Myofascial trigger points, pain, disability, and sleep quality in individuals with mechanical neck pain.

PubMed

Muñoz-Muñoz, Sonsoles; Muñoz-García, María T; Alburquerque-Sendín, Francisco; Arroyo-Morales, Manuel; Fernández-de-las-Peñas, César

2012-10-01

The purpose of this study was to investigate the presence of active myofascial trigger points (MTrPs) in a greater number of muscles than previous studies and the relation between the presence of MTrPs, the intensity of pain, disability, and sleep quality in mechanical neck pain. Fifteen patients with mechanical neck pain (80% women) and 12 comparable controls participated. Myofascial trigger points were bilaterally explored in the upper trapezius, splenius capitis, semispinalis capitis, sternocleidomastoid, levator scapulae, and scalene muscles in a blinded design. Myofascial trigger points were considered active if the subject recognized the elicited referred pain as a familiar symptom. Myofascial trigger points were considered latent if the elicited referred pain was not recognized as a symptom. Pain was collected with a numerical pain rate scale (0-10); disability was assessed with Neck Disability Index; and sleep quality, with the Pittsburgh Sleep Quality Index. Patients exhibited a greater disability and worse sleep quality than controls (P < .001). The Pittsburgh Sleep Quality Index score was associated with the worst intensity of pain (r = 0.589; P = .021) and disability (r = 0.552; P = .033). Patients showed a greater (P = .002) number of active MTrPs (mean, 2 ± 2) and similar number (P = .505) of latent MTrPs (1.6 ± 1.4) than controls (latent MTrPs, 1.3 ± 1.4). No significant association between the number of latent or active MTrPs and pain, disability, or sleep quality was found. The referred pain elicited by active MTrPs in the neck and shoulder muscles contributed to symptoms in mechanical neck pain. Patients exhibited higher disability and worse sleep quality than controls. Sleep quality was associated with pain intensity and disability. No association between active MTrPs and the intensity of pain, disability, or sleep quality was found. Copyright © 2012 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

Treatment of temporomandibular myofascial pain with deep dry needling

PubMed Central

Gonzalez-Perez, Luis M.; Granados-Nuñez, Mercedes; Urresti-Lopez, Francisco J.

2012-01-01

Objectives: The present study was designed to evaluate the usefulness of deep dry needling in the treatment of temporomandibular myofascial pain. Study Design: We selected 36 patients with myofascial pain located in the external pterygoid muscle (30 women/6 men, mean age=27 years with SD±6,5). We studied differences in pain with a visual analog scale and range of mandibular movements before and after intervention. Results: We found a statistically significant relationship (p<0,01) between therapeutic intervention and the improvement of pain and jaw movements, which continued up to 6 months after treatment. Pain reduction was greater the higher was the intensity of pain at baseline. Conclusions: Although further studies are needed, our findings suggest that deep dry needling in the trigger point in the external pterygoid muscle can be effective in the management of patients with myofascial pain located in that muscle. Key words:Temporomandibular joint, myofascial pain, external pterygoid muscle, trigger point, deep dry needling. PMID:22549679

Validity and Reliability of Clinical Examination in the Diagnosis of Myofascial Pain Syndrome and Myofascial Trigger Points in Upper Quarter Muscles.

PubMed

Mayoral Del Moral, Orlando; Torres Lacomba, María; Russell, I Jon; Sánchez Méndez, Óscar; Sánchez Sánchez, Beatriz

2017-12-15

To determine whether two independent examiners can agree on a diagnosis of myofascial pain syndrome (MPS). To evaluate interexaminer reliability in identifying myofascial trigger points in upper quarter muscles. To evaluate the reliability of clinical diagnostic criteria for the diagnosis of MPS. To evaluate the validity of clinical diagnostic criteria for the diagnosis of MPS. Validity and reliability study. Provincial Hospital. Toledo, Spain. Twenty myofascial pain syndrome patients and 20 healthy, normal control subjects, enrolled by a trained and experienced examiner. Ten bilateral muscles from the upper quarter were evaluated by two experienced examiners. The second examiner was blinded to the diagnosis group. The MPS diagnosis required at least one muscle to have an active myofascial trigger point. Three to four days separated the two examinations. The primary outcome measure was the frequency with which the two examiners agreed on the classification of the subjects as patients or as healthy controls. The kappa statistic (K) was used to determine the level of agreement between both examinations, interpreted as very good (0.81-1.00), good (0.61-0.80), moderate (0.41-0.60), fair (0.21-0.40), or poor (≤0.20). Interexaminer reliability for identifying subjects with MPS was very good (K = 1.0). Interexaminer reliability for identifying muscles leading to a diagnosis of MPS was also very good (K = 0.81). Sensitivity and specificity showed high values for most examination tests in all muscles, which confirms the validity of clinical diagnostic criteria in the diagnosis of MPS. Interrater reliability between two expert examiners identifying subjects with MPS involving upper quarter muscles exhibited substantial agreement. These results suggest that clinical criteria can be valid and reliable in the diagnosis of this condition. © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

The effect of trigger point management by positional release therapy on tension type headache.

PubMed

Ghanbari, Ali; Rahimijaberi, Abbas; Mohamadi, Marzieh; Abbasi, Leila; Sarvestani, Fahimeh Kamali

2012-01-01

The aim of this study was to compare the effectiveness of trigger points' management by Positional Release Therapy (PRT) and routine medical therapy in treatment of Tension Type Headache. Tension Type Headache is the most frequent headache with the basis of myofascial and trigger point disorders. PRT is an indirect technique that treats trigger points. 30 Patients with active trigger points in cervical muscles entered to the study. They were randomly assigned to PRT or medical therapy group. Headache frequency, intensity and duration and tablet count were recorded by use of a daily headache diary. Sensitivity of trigger points was assessed by numeric pain intensity and by use of a digital force gauge (FG 5020). Both groups showed significant reduction in headache frequency and duration and tablet count after treatment phase. However, the reduction of study variables was persisted only in PRT group after follow up phase. There was no significant reduction in headache intensity, neither in PRT and nor in medication group. Sensitivity of trigger points was significantly reduced. In comparison of the two study groups, there was no significant difference in headache frequency, intensity, duration and tablet count (p> 0.05). Both procedures were equally effective according to the study. Thus, PRT can be a treatment choice for patients with T.T.H.

Customized Interactive Robotic Treatment for Stroke: EMG-Triggered Therapy

PubMed Central

Dipietro, Laura; Ferraro, Mark; Palazzolo, Jerome Joseph; Krebs, Hermano Igo; Volpe, Bruce T.; Hogan, Neville

2009-01-01

A system for electromyographic (EMG) triggering of robot-assisted therapy (dubbed the EMG game) for stroke patients is presented. The onset of a patient’s attempt to move is detected by monitoring EMG in selected muscles, whereupon the robot assists her or him to perform point-to-point movements in a horizontal plane. Besides delivering customized robot-assisted therapy, the system can record signals that may be useful to better understand the process of recovery from stroke. Preliminary experiments aimed at testing the proposed system and gaining insight into the potential of EMG-triggered, robot-assisted therapy are reported. PMID:16200756

Comparison between newer local anesthetics for myofascial pain syndrome management.

PubMed

Zaralidou, A Th; Amaniti, E N; Maidatsi, P G; Gorgias, N K; Vasilakos, D F

2007-06-01

Myofascial pain syndromes are characterized by the presence of painful loci within muscles, tendons or ligaments, called trigger points. Infiltration of these points with local anesthetics is often used as a treatment modality. The aim of the study was to comparatively evaluate 0.25% levobupivacaine and 0.25% ropivacaine for trigger point injection regarding pain on injection, treatment efficacy and duration of symptoms remission. Sixty-eight patients, suffering from myofascial pain syndromes, were randomly assigned to two groups to receive either levobupivacaine or ropivacaine for trigger-point injection. After completion of the procedure, patients were asked to rate pain during injection and efficacy of the treatment, based on immediate relief. Two weeks later, they were asked about the duration of this relief. Statistical analysis did not reveal significant differences between groups with respect to pain during injection, efficacy of the treatment and duration of pain relief. The two local anesthetics seem to be equally effective for trigger point infiltration. (c) 2007 Prous Science. All rights reserved.

Kinesio taping and manual pressure release: Short-term effects in subjects with myofasical trigger point.

PubMed

Chao, Yu Wen; Lin, Jiu Jenq; Yang, Jing Lan; Wang, Wendy Tzyy-Jiuan

2016-01-01

Randomized controlled trial. Myofascial pain syndrome is characterized by myofascial trigger points (MTrPs) and fascia tenderness. We investigated the effects of manual pressure release (MPR) alone or in combination with taping (MPR/MKT) in subjects with MTrPs. Fifteen and 16 subjects received MPR and MPR/MKT respectively. Outcomes including Pressure pain threshold, muscle stiffness, mechanomyography were assessed at baseline, post-intervention and 7-days later. Pressure pain threshold improved significantly (d = 1.79, p < 0.005) in both groups. Significant improvement in muscle stiffness in the MPR/MKT group (0.27-0.49 mm) as compared to the MPR group (-0.02-0.23 mm). Mechanomyography amplitude in the MPR/MKT group was significantly higher than that of the MPR group (p < 0.05). MPR and MPR/MKT are effective in reducing pain in these subjects. MPR/MKT has a greater effect on muscle stiffness and contraction amplitude. IV. Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Myofascial Pain Syndrome

MedlinePlus

... to develop trigger points in their muscles. One theory holds that these people may be more likely ... doctors believe myofascial pain syndrome may play a role in starting this process. By Mayo Clinic Staff . ...

Tension - Type - Headache treated by Positional Release Therapy: a case report.

PubMed

Mohamadi, Marzieh; Ghanbari, Ali; Rahimi Jaberi, Abbas

2012-10-01

Tension Type Headache (T.T.H) is the most prevalent headache. Myofascial abnormalities & trigger points are important in this type of headache which can be managed by Positional Release Therapy (PRT). This is a report of a 47 years old female patient with Tension Type Headache treated by Positional Release Therapy for her trigger points. She had a constant dull headache, which continued all the day for 9 months. A physiotherapist evaluated the patient and found active trigger points in her cervical muscles. Then, she received Positional Release Therapy for her trigger points. After 3 treatment sessions, the patient's headache stopped completely. During the 8 months following the treatment she was without pain, and did not use any medication. Positional Release Therapy was effective in treating Tension Type Headache. This suggests that PRT could be an alternative treatment to medication in patients with T.T.H if the effectiveness of that can be confirmed by further studies. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effectiveness of dry needling for chronic nonspecific neck pain: a randomized, single-blinded, clinical trial.

PubMed

Cerezo-Téllez, Ester; Torres-Lacomba, María; Fuentes-Gallardo, Isabel; Perez-Muñoz, Milagros; Mayoral-Del-Moral, Orlando; Lluch-Girbés, Enrique; Prieto-Valiente, Luis; Falla, Deborah

2016-09-01

Chronic neck pain attributed to a myofascial pain syndrome is characterized by the presence of muscle contractures referred to as myofascial trigger points. In this randomized, parallel-group, blinded, controlled clinical trial, we examined the effectiveness of deep dry needling (DDN) of myofascial trigger points in people with chronic nonspecific neck pain. The study was conducted at a public Primary Health Care Centre in Madrid, Spain, from January 2010 to December 2014. A total of 130 participants with nonspecific neck pain presenting with active myofascial trigger points in their cervical muscles were included. These participants were randomly allocated to receive: DDN plus stretching (n = 65) or stretching only (control group [n = 65]). Four sessions of treatment were applied over 2 weeks with a 6-month follow-up after treatment. Pain intensity, mechanical hyperalgesia, neck active range of motion, neck muscle strength, and perceived neck disability were measured at baseline, after 2 sessions of intervention, after the intervention period, and 15, 30, 90, and 180 days after the intervention. Significant and clinically relevant differences were found in favour of dry needling in all the outcomes (all P < 0.001) at both short and long follow-ups. Deep dry needling and passive stretching is more effective than passive stretching alone in people with nonspecific neck pain. The results support the use of DDN in the management of myofascial pain syndrome in people with chronic nonspecific neck pain.

A comprehensive protocol to diagnose and treat pain of muscular origin may successfully and reliably decrease or eliminate pain in a chronic pain population.

PubMed

Marcus, Norman J; Gracely, Edward J; Keefe, Kelly O

2010-01-01

A comprehensive protocol is presented to identify muscular causes of regional pain syndromes utilizing an electrical stimulus in lieu of palpation, and combining elements of Prolotherapy with trigger point injections. One hundred seventy-six consecutive patients were evaluated for the presence of muscle pain by utilizing an electrical stimulus produced by the Muscle Pain Detection Device. The diagnosis of "Muscle Pain Amenable to Injection" (MPAI), rather than trigger points, was made if pain was produced for the duration of the stimulation. If MPAI was found, muscle tendon injections (MTI) were offered to patients along with post-MTI physical therapy, providing neuromuscular electrical stimulation followed by a validated exercise program [1]. A control group, evaluated 1 month prior to their actual consultation/evaluation when muscle pain was identified but not yet treated, was used for comparison. Forty-five patients who met criteria completed treatment. Patients' scores on the Brief Pain Inventory decreased an average of 62%; median 70% (P < 0.001) for pain severity and 68%; median 85% (P < 0.001) for pain interference one month following treatment. These changes were significantly greater (P < 0.001) than those observed in the untreated controls. A protocol incorporating an easily reproducible electrical stimulus to diagnose a muscle causing pain in a region of the body followed by an injection technique that involves the entirety of the muscle, and post injection restoration of muscle function, can successfully eliminate or significantly reduce regional pain present for years.

Thermographic and clinical correlation of myofascial trigger points in the masticatory muscles

PubMed Central

Haddad, D S; Brioschi, M L; Arita, E S

2012-01-01

Objectives The aim of the study was to identify and correlate myofascial trigger points (MTPs) in the masticatory muscles, using thermography and algometry. Methods 26 female volunteers were recruited. The surface facial area over the masseter and anterior temporalis muscles was divided into 15 subareas on each side (n = 780). This investigation consisted of three steps. The first step involved thermographic facial examination, using lateral views. The second step involved the pressure pain threshold (PPT), marking the MTP pattern areas for referred pain (n = 131) and local pain (n = 282) with a coloured pencil, and a photograph of the lateral face with the head in the same position as the infrared imaging. The last step was the fusion of these two images, using dedicated software (Reporter® 8.5—SP3 Professional Edition and QuickReport® 1.2, FLIR Systems, Wilsonville, OR); and the calculation of the temperature of each point. Results PPT levels measured at the points of referred pain in MTPs (1.28 ± 0.45 kgf) were significantly lower than the points of local pain in MTPs (1.73 ± 0.59 kgf; p < 0.05). Infrared imaging indicated differences between referred and local pain in MTPs of 0.5 °C (p < 0.05). Analysis of the correlation between the PPT and infrared imaging was done using the Spearman non-parametric method, in which the correlations were positive and moderate (0.4 ≤ r < 0.7). The sensitivity and specificity in MTPs were 62.5% and 71.3%, respectively, for referred pain, and 43.6% and 60.6%, respectively, for local pain. Conclusion Infrared imaging measurements can provide a useful, non-invasive and non-ionizing examination for diagnosis of MTPs in masticatory muscles. PMID:23166359

Improving understanding of trigger points and widespread pressure pain sensitivity in tension-type headache patients: clinical implications.

PubMed

Fernández-De-Las-Peñas, César; Arendt-Nielsen, Lars

2017-09-01

The underlying etiology of tension type headache (TTH) is not understood. The current paper highlights the etiologic role of muscle trigger points (TrPs) to the development and maintenance of central sensitization in TTH and its clinical repercussion for proper management of these patients. Areas covered: A literature search on Pub Med for English-language published papers between 1990 and May 2017 to provide the most updated data on the topic was conducted. Current literature suggests that the referred pain elicited by active trigger points (TrPs) contributes to the manifestations of TTH. There is also evidence supporting that TrPs represent a peripheral source of nociception and thereby a driver in the development of central sensitization. In fact, TrPs have been found to be associated with widespread pressure pain sensitivity in TTH. Temporal and spatial summation of TrP nociception suggests that inactivating TrP in the neck, head and shoulder muscles could help these patients; however, current evidence supporting the therapeutic role of TrPs in TTH is conflicting. Expert commentary: Understanding the role of TrPs in TTH in widespread pain sensitization may help to develop better management regimes and possibly prevent TTH from developing into more chronic conditions.

An Exploratory Study to Determine the Relationship between Cervical Dysfunction and Perimenstrual Migraines

PubMed Central

Horwitz, Simone

2015-01-01

ABSTRACT Purpose: To determine whether an association between cervical dysfunction and perimenstrual migraines exists. Methods: Forty perimenstrual migraine sufferers and 46 controls were compared. Information on the participants' ages and perceptions of neck pain and stiffness were solicited. The blinded physical examination of the cervical area consisted of postural, range of motion, muscle strength, muscle length, trigger point, neural mobility, and segmental cervical joint movement assessment. Results: The migraine group had increased perception of neck pain and stiffness (p<0.001); reduced bilateral rotation (p=0.013); decreased muscle length in both trapezii, left sternocleidomastoid, and right occipitals (p=0.045); more pain on muscle stretch in both levator scapulae, both trapezii, left sternocleidomastoid, and both occipitals (p=0.013); increased trigger points bilaterally in the left trapezius (p=0.021), right trapezius (p=0.023), left sternocleidomastoid (p=0.0.004), and right sternocleidomastoid (p=0.021); reduced neural mobility with bilateral elbow lag (p=0.043); greater C4–C6 pain (p=0.045); and increased cervical stiffness in C5–C7 (p=0.023). There were no differences in posture and muscle strength. Decreased muscle length increased the risk of perimenstrual migraines 2.4–6.7 fold, reduced neural mobility 5.8–10.7 fold, and increased C7 stiffness 17.0 fold. Conclusion: The results suggest that an association between cervical dysfunction and perimenstrual headaches should be further explored. PMID:25931651

Efficacy and Safety of Single Botulinum Toxin Type A (Botox®) Injection for Relief of Upper Trapezius Myofascial Trigger Point: A Randomized, Double-Blind, Placebo-Controlled Study.

PubMed

Kwanchuay, Photsawee; Petchnumsin, Thavatchai; Yiemsiri, Pichet; Pasuk, Nakkamol; Srikanok, Wannarat; Hathaiareerug, Chanasak

2015-12-01

Botulinum toxin injection has been applied for pain relief in various chronic pain syndromes. Recently, systematic review studies reported inconclusive effects of Botulinum toxin in myofascial pain management. The present study aimed to demonstrate the efficacy and safety of Botulinum toxin type A (BTxA) (Botox®) injection for pain reduction in myofascial trigger point (MTrP) of the upper trapezius muscle. Thirty-three patients with 48 MTrP on the upper trapezius muscles over three months with moderate to severe pain intensity diagnosed at physical medicine and rehabilitation outpatient department were recruited between December 2011 and March 2012. Eligible patients were blinded and randomly injected with single 0.2 ml (20 IU) of BTxA for 24 MTrP and 0.2 ml of 0.9% NaCl solution for 24 MTrP at the most tender trigger point on the upper trapezius muscle. All patients were advised for stretching exercise and ergonomic adaptation throughout the study. At 3- and 6-week after injections, visual analogue scale (VAS), the pressure pain threshold (PPT), and reported adverse effects were measured. Both BTxA and control groups demonstrated statistically significant differences in VAS reduction and increased PPT after 3 weeks and 6 weeks compared with before treatment. There were no statistically significant differences in VAS reduction from baseline between the two groups at 3- and 6-week after treatment. A statistically significant difference in improvement of PPT from baseline and 6-week after BTxA injection compared with 0.9% NaCl group was shown (1.0 ± 0.9 and 0.5 ± 0.7, p = 0.036). There was mild degree side-effects that spontaneous resolved within one week in both groups without significant difference in percentage. No severe adverse effects were reported during the study. The efficacy in VAS reduction of a single 20 IU of Botulinum toxin type A (Botox®) injection was not different from 0.9% NaCl for myofascial trigger point at the upper trapezius muscle. However Botulinum toxin type A (Botox®) showed statistically significant more increased in pressure pain threshold at 6-week after injection without severe adverse effects.

Regenerating muscle with arginine methylation

PubMed Central

Blanc, Roméo S.; Richard, Stéphane

2017-01-01

ABSTRACT Protein arginine methyltransferase (PRMT) is a family of nine proteins catalyzing the methylation of arginine residues. They were recently shown to be essential for proper regeneration of skeletal muscles. However, the mechanisms triggering the methylation event, as well as how the methylated substrates regulate muscle stem cell function and fate decision remain to be determined. This point-of-view will discuss the recent findings on the specific role of PRMT1, CARM1/PRMT4, PRMT5, and PRMT7 in muscle stem cell fate guidance, and shed light on the future challenges which could help defining the therapeutic potential of PRMT inhibitors against muscular disorders and aging. PMID:28301308

Regenerating muscle with arginine methylation.

PubMed

Blanc, Roméo S; Richard, Stéphane

2017-05-27

Protein arginine methyltransferase (PRMT) is a family of nine proteins catalyzing the methylation of arginine residues. They were recently shown to be essential for proper regeneration of skeletal muscles. However, the mechanisms triggering the methylation event, as well as how the methylated substrates regulate muscle stem cell function and fate decision remain to be determined. This point-of-view will discuss the recent findings on the specific role of PRMT1, CARM1/PRMT4, PRMT5, and PRMT7 in muscle stem cell fate guidance, and shed light on the future challenges which could help defining the therapeutic potential of PRMT inhibitors against muscular disorders and aging.

Trigger point-related sympathetic nerve activity in chronic sciatic leg pain: a case study.

PubMed

Skorupska, Elżbieta; Rychlik, Michał; Pawelec, Wiktoria; Bednarek, Agata; Samborski, Włodzimierz

2014-10-01

Sciatica has classically been associated with irritation of the sciatic nerve by the vertebral disc and consequent inflammation. Some authors suggest that active trigger points in the gluteus minimus muscle can refer pain in similar way to sciatica. Trigger point diagnosis is based on Travel and Simons criteria, but referred pain and twitch response are significant confirmatory signs of the diagnostic criteria. Although vasoconstriction in the area of a latent trigger point has been demonstrated, the vasomotor reaction of active trigger points has not been examined. We report the case of a 22-year-old Caucasian European man who presented with a 3-year history of chronic sciatic-type leg pain. In the third year of symptoms, coexistent myofascial pain syndrome was diagnosed. Acupuncture needle stimulation of active trigger points under infrared thermovisual camera showed a sudden short-term vasodilatation (an autonomic phenomenon) in the area of referred pain. The vasodilatation spread from 0.2 to 171.9 cm(2) and then gradually decreased. After needling, increases in average and maximum skin temperature were seen as follows: for the thigh, changes were +2.6°C (average) and +3.6°C (maximum); for the calf, changes were +0.9°C (average) and +1.4°C (maximum). It is not yet known whether the vasodilatation observed was evoked exclusively by dry needling of active trigger points. The complex condition of the patient suggests that other variables might have influenced the infrared thermovision camera results. We suggest that it is important to check if vasodilatation in the area of referred pain occurs in all patients with active trigger points. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Myofascial trigger point-focused head and neck massage for recurrent tension-type headache: A randomized, placebo-controlled clinical trial

PubMed Central

Moraska, Albert F.; Stenerson, Lea; Butryn, Nathan; Krutsch, Jason P.; Schmiege, Sarah J.; Mann, J. Douglas

2014-01-01

Objective Myofascial trigger points (MTrPs) are focal disruptions in skeletal muscle that can refer pain to the head and reproduce the pain patterns of tension-type headache (TTH). The present study applied massage focused on MTrPs of subjects with TTH in a placebo-controlled, clinical trial to assess efficacy on reducing headache pain. Methods Fifty-six subjects with TTH were randomized to receive 12 massage or placebo (detuned ultrasound) sessions over six weeks, or to wait-list. Trigger point release (TPR) massage focused on MTrPs in cervical musculature. Headache pain (frequency, intensity and duration) was recorded in a daily headache diary. Additional outcome measures included self-report of perceived clinical change in headache pain and pressure-pain threshold (PPT) at MTrPs in the upper trapezius and sub-occipital muscles. Results From diary recordings, group differences across time were detected in headache frequency (p=0.026), but not for intensity or duration. Post hoc analysis indicated headache frequency decreased from baseline for both massage (p<0.0003) and placebo (p=0.013), but no difference was detected between massage and placebo. Subject report of perceived clinical change was a greater reduction in headache pain for massage than placebo or wait-list groups (p=0.002). PPT improved in all muscles tested for massage only (all p's<0.002). Discussion Two findings from this study are apparent: 1) MTrPs are important components in the treatment of TTH, and 2) TTH, like other chronic conditions, is responsive to placebo. Clinical trials on headache that do not include a placebo group are at risk for overestimating the specific contribution from the active intervention. PMID:25329141

Myofascial trigger point-focused head and neck massage for recurrent tension-type headache: a randomized, placebo-controlled clinical trial.

PubMed

Moraska, Albert F; Stenerson, Lea; Butryn, Nathan; Krutsch, Jason P; Schmiege, Sarah J; Mann, John D

2015-02-01

Myofascial trigger points (MTrPs) are focal disruptions in the skeletal muscle that can refer pain to the head and reproduce the pain patterns of tension-type HA (TTH). The present study applied massage focused on MTrPs of patients with TTH in a placebo-controlled, clinical trial to assess efficacy on reducing headache (HA) pain. Fifty-six patients with TTH were randomized to receive 12 massage or placebo (detuned ultrasound) sessions over 6 weeks, or to wait-list. Trigger point release massage focused on MTrPs in cervical musculature. HA pain (frequency, intensity, and duration) was recorded in a daily HA diary. Additional outcome measures included self-report of perceived clinical change in HA pain and pressure-pain threshold at MTrPs in the upper trapezius and suboccipital muscles. From diary recordings, group differences across time were detected in HA frequency (P=0.026), but not for intensity or duration. Post hoc analysis indicated that HA frequency decreased from baseline for both massage (P<0.0003) and placebo (P=0.013), but no difference was detected between massage and placebo. Patient report of perceived clinical change was greater reduction in HA pain for massage than placebo or wait-list groups (P=0.002). Pressure-pain threshold improved in all muscles tested for massage only (all P's<0.002). Two findings from this study are apparent: (1) MTrPs are important components in the treatment of TTH, and (2) TTH, like other chronic conditions, is responsive to placebo. Clinical trials on HA that do not include a placebo group are at risk for overestimating the specific contribution from the active intervention.

Effectiveness of dry needling on the lower trapezius in patients with mechanical neck pain: a randomized controlled trial.

PubMed

Pecos-Martín, Daniel; Montañez-Aguilera, F Javier; Gallego-Izquierdo, Tomás; Urraca-Gesto, Alicia; Gómez-Conesa, Antonia; Romero-Franco, Natalia; Plaza-Manzano, Gustavo

2015-05-01

To evaluate the effect of dry needling into a myofascial trigger point (MTrP) in the lower trapezius muscle of patients with mechanical idiopathic neck pain. A single-center, randomized, double-blinded controlled study. Patients were recruited from the student population of a local hospital by advertisement in the university clinic from January 2010 to December 2011. Patients (N=72) with unilateral neck pain, neck pain for ≥3 months, and active trigger points in the lower trapezius muscle were randomly assigned to 1 of 2 treatment groups. All the patients completed the study. Dry needling in an MTrP in the lower trapezius muscle, or dry needling in the lower trapezius muscle but not at an MTrP. The visual analog scale (VAS), Neck Pain Questionnaire (NPQ), and pressure-pain threshold (PPT) were assessed before the intervention and 1 week and 1 month postintervention. Treatment with dry needling of the lower trapezius muscle close to the MTrP showed decreases in pain and PPT as well as an improvement in the degree of disability (P<.001) compared with the baseline and control group measurements (P<.001). The dry-needling technique performed in the MTrP showed more significant therapeutic effects (P<.001). The application of dry needling into an active MTrP of the lower trapezius muscle induces significant changes in the VAS, NPQ, and PPT levels compared with the application of dry needling in other locations of the same muscle in patients with mechanical neck pain. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Nonlinear analysis of electromyogram following gait training with myoelectrically triggered neuromuscular electrical stimulation in stroke survivors

NASA Astrophysics Data System (ADS)

Dutta, Anirban; Khattar, Bhawna; Banerjee, Alakananda

2012-12-01

Neuromuscular electrical stimulation (NMES) facilitates ambulatory function after paralysis by activating the muscles of the lower extremities. The NMES-assisted stepping can either be triggered by a heel-switch (switch-trigger), or by an electromyogram (EMG)-based gait event detector (EMG-trigger). The command sources—switch-trigger or EMG-trigger—were presented to each group of six chronic (>6 months post-stroke) hemiplegic stroke survivors. The switch-trigger group underwent transcutaneous NMES-assisted gait training for 1 h, five times a week for 2 weeks, where the stimulation of the tibialis anterior muscle of the paretic limb was triggered with a heel-switch detecting heel-rise of the same limb. The EMG-trigger group underwent transcutaneous NMES-assisted gait training of the same duration and frequency where the stimulation was triggered with surface EMG from medial gastrocnemius (MG) of the paretic limb in conjunction with a heel-switch detecting heel-rise of the same limb. During the baseline and post-intervention surface EMG assessment, a total of 10 s of surface EMG was recorded from bilateral MG muscle while the subjects tried to stand steady on their toes. A nonlinear tool—recurrence quantification analysis (RQA)—was used to analyze the surface EMG. The objective of this study was to find the effect of NMES-assisted gait training with switch-trigger or EMG-trigger on two RQA parameters—the percentage of recurrence (%Rec) and determinism (%Det), which were extracted from surface EMG during fatiguing contractions of the paretic muscle. The experimental results showed that during fatiguing contractions, (1) %Rec and %Det have a higher initial value for paretic muscle than the non-paretic muscle, (2) the rate of change in %Rec and %Det was negative for the paretic muscle but positive for the non-paretic muscle, (3) the rate of change in %Rec and %Det significantly increased from baseline for the paretic muscle after EMG-triggered NMES-assisted gait training. Therefore, the study showed an improvement in paretic muscle function during a fatiguing task following gait training with EMG-triggered NMES. This study also showed that RQA parameters—%Rec and %Det—were sensitive to changes in paretic/non-paretic muscle properties due to gait training and can be used for non-invasive muscle monitoring in stroke survivors undergoing rehabilitation.

Myofascial involvement of supra- and infraspinatus muscles contributes to ipsilateral shoulder pain after muscle-sparing thoracotomy and video-assisted thoracic surgery.

PubMed

Ohmori, Aki; Iranami, Hiroshi; Fujii, Keisuke; Yamazaki, Akinori; Doko, Yukari

2013-12-01

This study examined the hypothesis that ipsilateral upper extremity elevation for muscle-sparing thoracotomy procedures contributes to the postoperative shoulder pain. Prospective observational study. Medical center. ASA physical status 1-2 patients undergoing elective lung surgeries including pneumonectomy, lobectomy, and segmentectomy performed through either the anterolateral approach or video-assisted thoracotomy surgery. Postoperative observation of ipsilateral shoulder pain. Postoperative examinations of sites of shoulder pain (clavicle, anterior, lateral,or posterior aspect of acromion, posterior neck, supraspinatus, infraspinatus, and these entire areas) with or without trigger points, visual analog scale score of wound pain, and requested counts of analgesics. The number of patients who suffered from postoperative shoulder pain was 37 of 70 (52.9%). Demographic data, anterolateral/VATS ratio, VAS scores, and requested counts of rescue analgesics requirement were similar in the groups of patients with and without postoperative shoulder pain. The segmentectomy caused a significantly higher incidence of postoperative shoulder pain compared with other procedures (p < 0.05). The supra- and infraspinatus were significantly higher areas of painful regions compared to the other sites. The 16 of 37 patients (43.2%) with shoulder pain showed defined trigger points in their painful areas. These results supported the hypothesis that myofascial involvement contributed, to some extent, to shoulder pain after muscle-sparing thoracotomy with ipsilateral upper extremity elevation. Copyright © 2013 Elsevier Inc. All rights reserved.

Short-Term Effects of Kinesio Taping and Cross Taping Application in the Treatment of Latent Upper Trapezius Trigger Points: A Prospective, Single-Blind, Randomized, Sham-Controlled Trial

PubMed Central

Słupska, Lucyna; Paprocka-Borowicz, Małgorzata; Taradaj, Jakub; Bidzińska, Gabriela; Marczyński, Daniel; Cynarska, Aleksandra; Rosińczuk, Joanna

2015-01-01

Kinesio taping (KT) may be a new treatment in patients with myofascial trigger points (MTrPs). A new method available for taping practitioners is cross taping (CT). The main objective was to determine how CT, KT, and medical adhesive tape (sham group) affect the subjective assessment of resting bioelectrical activity and pain of the upper trapezius muscle (UT) in patients with MTrPs. 105 volunteers were recruited to participate. The primary outcome was resting bioelectrical activity of UT muscle as assessed by surface electromyography (sEMG) in each group and pain intensity on a visual analog scale (VAS). Assessments were collected before and after intervention and after the 24-hours follow-up. No significant differences were observed in bioelectrical activity of UT between pre-, post-, and follow-up results. In three groups patients had significantly lower pain VAS score after the intervention (CT—p < 0.001, KT—p < 0.001, and sham—p < 0.01). The Kruskal-Wallis ANOVA showed no significant differences in almost all measurements between groups. The application of all three types of tapes does not influence the resting bioelectrical activity of UT muscle and may not lead to a reduction in muscle tone in the case of MTrPs. PMID:26491458

Association of cross-sectional area of the rectus capitis posterior minor muscle with active trigger points in chronic tension-type headache: a pilot study.

PubMed

Fernández-de-Las-Peñas, César; Cuadrado, María Luz; Arendt-Nielsen, Lars; Ge, Hong-You; Pareja, Juan A

2008-03-01

To investigate whether cross-sectional area (CSA) of the suboccipital muscles was associated with active trigger points (TrPs) in chronic tension-type headache (CTTH). Magnetic resonance imaging (MRI) of the cervical spine was performed in 11 females with CTTH aged from 26 to 50 yrs old. CSA for both rectus capitis posterior minor (RCPmin) and rectus capitis posterior major (RCPmaj) muscles were measured from axial T1-weighted images, using axial MRI slices aligned parallel to the C2/3 intervertebral disc. A headache diary was kept for 4 wks to record the pain history. TrPs in the suboccipital muscle were identified by eliciting referred pain to palpation, and increased referred pain with muscle contraction. TrPs were considered active if the elicited referred pain reproduced the head pain pattern and features of the pattern seen during spontaneous headache attacks. Active TrPs were found in six patients (55%), whereas the remaining five patients showed latent TrPs. CSA of the RCPmin was significantly smaller (F = 13.843; P = 0.002) in the patients with active TrPs (right side: 55.9 +/- 4.4 mm; left side: 61.1 +/-: 3.8 mm) than in patients with latent TrPs (right side: 96.9 +/- 14.4 mm; left side: 88.7 +/- 9.7 mm). No significant differences were found for CSA of the RCPmaj between the patients with either active or latent TrP (P > 0.5). It seems that muscle atrophy in the RCPmin, but not in the RCPmaj, was associated with suboccipital active TrPs in CTTH, although studies with larger sample sizes are now required. It may be that nociceptive inputs in active TrPs could lead to muscle atrophy of the involved muscles. Muscle disuse or avoidance behavior can also be involved in atrophy.

Transvaginal Pelvic Floor Muscle Injection Technique: A Cadaver Study.

PubMed

Gupta, Priyanka; Ehlert, Michael; Sirls, Larry T; Peters, Kenneth

Women with pelvic floor dysfunction can have tender areas on vaginal examination, which can be treated with trigger-point injections. There are no publications to evaluate the accuracy of pelvic floor muscle injections. Trigger-point injections were performed on 2 fresh cadaveric pelvises using a curved nasal cannula guide and 7-in spinal needle. This was performed using our standard template of 2 sets of injections at the 1-, 3-, and 5-o'clock positions distally and proximally. The first pelvis was dissected to examine dye penetration. Based on these results, we modified our technique and repeated the injections on the second cadaver. We dissected the second pelvis and compared our findings. The 1-o'clock proximal and distal injections stained the obturator internus and externus near the insertion at the ischiopubic ramus. The 3-o'clock injections stained the midbody of the pubococcygeus and puborectalis. The distal 5-o'clock position was too deep and stained the fat of the ischiorectal space. The proximal 5-o'clock injection stained the area of the pudendal nerve. Our goal at the distal 5-o'clock position was to infuse the iliococcygeus muscle, so we shortened the needle depth from 2 to 1 cm beyond the cannula tip. In our second dissection, the distal 5-o'clock injection again stained only the fat of the ischiorectal space. This is the first study to characterize the distribution of pelvic floor muscle injections in a cadaver model and confirms the ability to deliver medications effectively to the pelvic floor muscles.

The influence of Positional Release Therapy on the myofascial trigger points of the upper trapezius muscle in computer users.

PubMed

Mohammadi Kojidi, M; Okhovatian, F; Rahimi, A; Baghban, A A; Azimi, H

2016-10-01

The purpose of the present study was to investigate the effect of Positional Release Therapy (PRT) in computer users via latent trigger points (LTrPs) of the upper trapezius muscle. Twenty-eight women with the upper trapezius MTrPs participated in this study. Subjects were randomly classified into two groups (14 in each group): the subjects in the Group 1 received PRT in shortened position while those in the group 2 received sham control in the neutral position of the upper trapezius muscle. They received three therapy sessions every other day for one week. The local pain intensity and Pressure pain threshold (PPT) were measured via Visual Analogue Scale (VAS) and algometry, respectively, before interventions and repeated 5 min after the first and third treatment sessions in each group. One-way ANOVA was used for data analysis. After treatment, between groups comparison revealed that for PPT and VAS, there were significant differences between the two groups (VAS and PPT; P < 0.05). Both groups (PRT and sham control) showed alleviation of pain and increase in PPT during three sessions of therapy although PRT showed to be more effective in these patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

Postneedling soreness after deep dry needling of a latent myofascial trigger point in the upper trapezius muscle: Characteristics, sex differences and associated factors.

PubMed

Martín-Pintado-Zugasti, Aitor; Rodríguez-Fernández, Ángel Luis; Fernandez-Carnero, Josue

2016-04-27

Postneedling soreness is considered the most frequent secondary effect associated to dry needling. A detailed description of postneedling soreness characteristics has not been previously reported. (1) to assess the intensity and duration of postneedling soreness and tenderness after deep dry needling of a trapezius latent myofascial trigger point (MTrP), (2) to evaluate the possible differences in postneedling soreness between sexes and (3) to analyze the influence on postneedling soreness of factors involved in the dry needling process. Sixty healthy subjects (30 men, 30 women) with latent MTrPs in the upper trapezius muscle received a dry needling intervention in the MTrP. Pain and pressure pain threshold (PPT) were assessed during a 72 hours follow-up period. Repeated measures analysis of covariance showed a significant effect for time in pain and in PPT. An interaction between sex and time in pain was obtained: women exhibited higher intensity in postneedling pain than men. The pain during needling and the number of needle insertions significantly correlated with postneedling soreness. Soreness and hyperalgesia are present in all subjects after dry needling of a latent MTrP in the upper trapezius muscle. Women exhibited higher intensity of postneedling soreness than men.

The immediate effects of traditional Thai massage on heart rate variability and stress-related parameters in patients with back pain associated with myofascial trigger points.

PubMed

Buttagat, Vitsarut; Eungpinichpong, Wichai; Chatchawan, Uraiwon; Kharmwan, Samerduen

2011-01-01

The purpose of this study was to investigate the immediate effects of traditional Thai massage (TTM) on stress-related parameters including heart rate variability (HRV), anxiety, muscle tension, pain intensity, pressure pain threshold, and body flexibility in patients with back pain associated with myofascial trigger points. Thirty-six patients were randomly allocated to receive a 30-min session of either TTM or control (rest on bed) for one session. Results indicated that TTM was associated with significant increases in HRV (increased total power frequency (TPF) and high frequency (HF)), pressure pain threshold (PPT) and body flexibility (p<0.05) and significant decreases in self-reported pain intensity, anxiety and muscle tension (p<0.001). For all outcomes, similar changes were not observed in the control group. The adjusted post-test mean values for TPF, HF, PPT and body flexibility were significantly higher in the TTM group when compared with the control group (p<0.01) and the values for pain intensity, anxiety and muscle tension were significantly lower. We conclude that TTM can increase HRV and improve stress-related parameters in this patient population. Copyright © 2009 Elsevier Ltd. All rights reserved.

Changes in pressure pain sensitivity in latent myofascial trigger points in the upper trapezius muscle after a cervical spine manipulation in pain-free subjects.

PubMed

Ruiz-Sáez, Mariana; Fernández-de-las-Peñas, César; Blanco, Cleofás Rodríguez; Martínez-Segura, Raquel; García-León, Rafael

2007-10-01

This study analyzed the immediate effects on pressure pain threshold (PPT) in latent myofascial trigger points (MTrPs) in the upper trapezius muscle of a single cervical spine manipulation directed at the C3 through C4 level. Seventy-two volunteers (27 men and 46 women; mean age, 31 years; SD, 10 years) participated in this study. Subjects underwent a screening process to establish both the presence of MTrPs in the upper trapezius muscle as described by Simons et al (Myofascial pain and dysfunction: the trigger point manual, vol 2. 3rd ed. Baltimore: Williams & Wilkins, 1999. p. 23-34) and the presence of intervertebral joint dysfunction at the C3 through C4 level by the lateral gliding test for the cervical spine. Subjects were divided randomly into 2 groups: manipulative group, which received a cervical spine manipulation directed at the C3 through C4 level, and a placebo group, which received a sham manual procedure. The outcome measure was the PPT on the MTrP in the upper trapezius muscle ipsilateral to the side of the joint dysfunction, which was assessed pretreatment and 1, 5, and 10 minutes posttreatment by an assessor blinded to the treatment allocation of the subject. The analysis of variance showed a significant effect for time (F = 5.157; P = .02) but not for side (F = 0.234; P = .63). Furthermore, an interaction between group and time was also found (F = 37.240; P < .001). The experimental group showed a trend toward an increase in PPT levels after the manipulative procedure, whereas the control group showed a trend toward a decrease in PPT. Positive within-group effect sizes ranging from medium to small were found in the manipulative group (0.1

Physical therapy in the treatment of fibromyalgia.

PubMed

Offenbächer, M; Stucki, G

2000-01-01

Fibromyalgia (FM) is a syndrome of unknown etiology characterized by chronic wide spread pain, increased tenderness to palpation and additional symptoms such as disturbed sleep, stiffness, fatigue and psychological distress. While medication mainly focus on pain reduction, physical therapy is aimed at disease consequences such as pain, fatigue, deconditioning, muscle weakness and sleep disturbances and other disease consequences. We systematically reviewed current treatment options in the treatment of fibromyalgia. Based on evidence from randomized controlled trials cardiovascular fitness training importantly improves cardiovascular fitness, both subjective and objective measures of pain as well as subjective energy and work capacity and physical and social activities. Based on anecdotal evidence or small observational studies physiotherapy may reduce overloading of the muscle system, improve postural fatigue and positioning, and condition weak muscles. Modalities and whole body cryotherapy may reduce localized as well as generalized pain in short term. Trigger point injection may reduce pain originating from concomitant trigger points in selected FM patient. Massage may reduce muscle tension and may be prescribed as a adjunct with other therapeutic interventions. Acupuncture may reduce pain and increase pain threshold. Biofeedback may positively influence subjective and objective disease measures. TENS may reduce localized musculoskeletal pain in fibromyalgia. While there seems to be no single best treatment option, physical therapy seem to reduce disease consequences. Accordingly a multidisciplinary approach combining these therapies in a well balanced program may be the most promising strategy and is currently recommended in the treatment of fibromyalgia.

Myofascial Trigger Points Then and Now: A Historical and Scientific Perspective

PubMed Central

Shah, Jay P.; Thaker, Nikki; Heimur, Juliana; Aredo, Jacqueline V.; Sikdar, Siddhartha; Gerber, Lynn H.

2015-01-01

The intent of this paper is to discuss the evolving role of the myofascial trigger point (MTrP) in myofascial pain syndrome (MPS) from both a historical and scientific perspective. MTrPs are hard, discrete, palpable nodules in a taut band of skeletal muscle that may be spontaneously painful (i.e. active), or painful only on compression (i.e. latent). MPS is a term used to describe a pain condition which can be acute or, more commonly, chronic and involves the muscle and its surrounding connective tissue (e.g. fascia). According to Travell and Simons, MTrPs are central to the syndrome—but are they necessary? Although the clinical study of muscle pain and MTrPs has proliferated over the past two centuries, the scientific literature often seems disjointed and confusing. Unfortunately, much of the terminology, theories, concepts, and diagnostic criteria are inconsistent, incomplete, or controversial. In order to address these deficiencies, investigators have recently applied clinical, imaging (of skeletal muscle and brain), and biochemical analyses to systematically and objectively study the MTrP and its role in MPS. Data suggest that the soft tissue milieu around the MTrP, neurogenic inflammation, sensitization, and limbic system dysfunction may all play a role in the initiation, amplification, and perpetuation of MPS. The authors will chronicle the advances that have led to the current understanding of MTrP pathophysiology and its relationship to MPS, and review the contributions of clinicians and researchers who have influenced and expanded our contemporary level of clinical knowledge and practice. PMID:25724849

Are tender point injections beneficial: the role of tonic nociception in fibromyalgia.

PubMed

Staud, Roland

2006-01-01

Characteristic symptoms of fibromyalgia syndrome (FM) include widespread pain, fatigue, sleep abnormalities, and distress. FM patients show psychophysical evidence for mechanical, thermal, and electrical hyperalgesia. To fulfill FM criteria, the mechanical hyperalgesia needs to be widespread and present in at least 11 out of 18 well-defined body areas (tender points). Peripheral and central abnormalities of nociception have been described in FM and these changes may be relevant for the increased pain experienced by these patients. Important nociceptor systems in the skin and muscle seem to undergo profound changes in FM patients by yet unknown mechanisms. These changes may result from the release of algesic substances after muscle or other soft tissue injury. These pain mediators can sensitize important nociceptor systems, including the transient receptor potential channel, vanilloid subfamily member 1 (TRPV1), acid sensing ion channel (ASIC) receptors, and purino-receptors (P2X3). Subsequently, tissue mediators of inflammation and nerve growth factors can excite these receptors and cause substantial changes in pain sensitivity. FM pain is widespread and does not seem to be restricted to tender points (TP). It frequently comprises multiple areas of deep tissue pain (trigger points) with adjacent much larger areas of referred pain. Analgesia of areas of extensive nociceptive input has been found to provide often long lasting local as well as general pain relief. Thus interventions aimed at reducing local FM pain seem to be effective but need to focus less on tender points but more on trigger points (TrP) and other body areas of heightened pain and inflammation.

The immediate effects of atlanto-occipital joint manipulation and suboccipital muscle inhibition technique on active mouth opening and pressure pain sensitivity over latent myofascial trigger points in the masticatory muscles.

PubMed

Oliveira-Campelo, Natalia M; Rubens-Rebelatto, José; Martí N-Vallejo, Francisco J; Alburquerque-Sendí N, Francisco; Fernández-de-Las-Peñas, César

2010-05-01

A randomized controlled trial. To investigate the immediate effects on pressure pain thresholds over latent trigger points (TrPs) in the masseter and temporalis muscles and active mouth opening following atlanto-occipital joint thrust manipulation or a soft tissue manual intervention targeted to the suboccipital muscles. Previous studies have described hypoalgesic effects of neck manipulative interventions over TrPs in the cervical musculature. There is a lack of studies analyzing these mechanisms over TrPs of muscles innervated by the trigeminal nerve. One hundred twenty-two volunteers, 31 men and 91 women, between the ages of 18 and 30 years, with latent TrPs in the masseter muscle, were randomly divided into 3 groups: a manipulative group who received an atlanto-occipital joint thrust, a soft tissue group who received an inhibition technique over the suboccipital muscles, and a control group who did not receive an intervention. Pressure pain thresholds over latent TrPs in the masseter and temporalis muscles, and active mouth opening were assessed pretreatment and 2 minutes posttreatment by a blinded assessor. Mixed-model analyses of variance (ANOVA) were used to examine the effects of interventions on each outcome, with group as the between-subjects variable and time as the within-subjects variable. The primary analysis was the group-by-time interaction. The 2-by-3 mixed-model ANOVA revealed a significant group-by-time interaction for changes in pressure pain thresholds over masseter (P<.01) and temporalis (P = .003) muscle latent TrPs and also for active mouth opening (P<.001) in favor of the manipulative and soft tissue groups. Between-group effect sizes were small. The application of an atlanto-occipital thrust manipulation or soft tissue technique targeted to the suboccipital muscles led to an immediate increase in pressure pain thresholds over latent TrPs in the masseter and temporalis muscles and an increase in maximum active mouth opening. Nevertheless, the effects of both interventions were small and future studies are required to elucidate the clinical relevance of these changes. Therapy, level 1b.J Orthop Sports Phys Ther 2010;40(5):310-317, Epub 12 April 2010. doi:10.2519/jospt.2010.3257.

Botulinum toxin for myofascial pain syndromes in adults.

PubMed

Soares, Adriana; Andriolo, Régis B; Atallah, Alvaro N; da Silva, Edina M K

2014-07-25

This is an updated version of the original Cochrane review published in Issue 4, 2012. Myofascial pain syndrome (MPS) is a regional muscular pain syndrome characterised by the presence of trigger points, which are painful points in one or more muscles. The pain can be felt at the site where the trigger point is located or it can be felt away from that place when the muscle is pressed (referred pain). Botulinum toxin is a protein produced by the bacterium Clostridium botulinum and is a potent neurotoxin that eventually inhibits muscle contractions. It is capable of selectively weakening painful muscles and interrupting the pain cycle. To assess the effectiveness and safety of botulinum toxin A (BTXA) in the treatment of myofascial pain syndrome (MPS), excluding MPS in neck and head muscles. This is an updated version of the original Cochrane review published in Issue 4, 2012. The search strategy for the update was the same as in the original review and we searched CENTRAL in The Cochrane Library (2013, Issue 11 of 12), MEDLINE (Ovid) (2012 to 29 November 2013) and EMBASE (Ovid) (2012 to 27 November 2013). The search strategy was composed of terms for myofascial pain and botulinum toxin. For the original review, we also searched the Cochrane Pain, Palliative and Supportive Care (PaPaS) Review Group Specialised Register until December 2011, PubMed (from 1966 to 2011) and LILACS (from 1982 to 2011). There was no language restriction. We included randomised controlled trials (RCTs) involving botulinum toxin for treating participants with MPS. We excluded studies with MPS of the neck and head from this review as they have already been assessed in existing systematic reviews. We considered a diagnosis of MPS to be based on the identification of trigger points in the taut band through palpation of sensitive nodules, local twitch response and specific patterns of referred pain associated with each trigger point. Two review authors independently screened identified studies, extracted data, assessed trial quality and analysed results using the Cochrane PaPaS Review Group criteria. Four studies with a total of 233 participants, comparing BTXA with placebo, met the inclusion criteria. In one study with 145 participants, significant improvement rates of pain intensity scores and duration of daily pain were demonstrated when comparing BTXA with placebo. The three other studies showed that there was no statistically significant difference between BTXA and placebo in pain intensity. Since the first publication of this review, no new studies were found. There is inconclusive evidence to support the use of botulinum toxin in the treatment of MPS based on data from four studies with a total of 233 participants, which we considered were of sufficient quality to be included in this review. Meta-analyses were not possible due to the heterogeneity between studies. We suggest that in future studies the same methodology to assess pain, a standardised dose of treatment, follow-up of at least four months (to observe the maximum and minimum curve of the drug effect) and appropriate data presentation should be used. More high-quality RCTs of botulinum toxin for treating MPS need to be conducted before firm conclusions on its effectiveness and safety can be drawn.

Botox combined with myofascial release physical therapy as a treatment for myofascial pelvic pain

PubMed Central

Scott, Lauren; Wyman, Allison; Mora, Nelsi; Miladinovic, Branko; Bassaly, Renee; Hoyte, Lennox

2017-01-01

Purpose To report the effects of combined onabotulinumtoxinA (Botox) injections and myofascial release physical therapy on myofascial pelvic pain (MFPP) by comparing pre- and posttreatment average pelvic pain scores, trigger points, and patient self-reported pelvic pain. Secondary outcomes were to examine posttreatment complications and determine demographic differences between patients with/without an improvement in pain. Materials and Methods This was an Institutional Review Board approved retrospective case series on women over 18 years with MFPP who received Botox and physical therapy between July 2006 and November 2014. Presence of trigger points and pelvic pain scores were determined by digital palpation of the iliococcygeus, puborectalis, obturator internus, and rectus muscles. Average pelvic pain scores (0–10) reflected an average of the scores obtained from palpation of each muscle. Self-reported improvement in pain was recorded as yes/no. Results Fifty women met the inclusion/exclusion criteria. Posttreatment, patients had lower average pelvic pain scores (3.7±4.0 vs. 6.4±1.8, p=0.005), and fewer trigger points (44% vs. 100%, p<0.001). Fifty-eight percent of patients (95% confidence interval, 44–72) noted an improvement in self-reported pain. Patients most likely to report no improvement in pain had chronic bowel disorders, while those most likely to report an improvement in pain had a history of past incontinence sling (p=0.03). Posttreatment complications included: constipation (8%), worsening urinary retention (2%), and urinary tract infection (4%). Conclusions Botox combined with soft tissue myofascial release physical therapy under anesthesia can be effective in treating women with chronic pelvic pain secondary to MFPP. PMID:28261683

Neuro Emotional Technique for the treatment of trigger point sensitivity in chronic neck pain sufferers: A controlled clinical trial

PubMed Central

Bablis, Peter; Pollard, Henry; Bonello, Rod

2008-01-01

Background Trigger points have been shown to be active in many myofascial pain syndromes. Treatment of trigger point pain and dysfunction may be explained through the mechanisms of central and peripheral paradigms. This study aimed to investigate whether the mind/body treatment of Neuro Emotional Technique (NET) could significantly relieve pain sensitivity of trigger points presenting in a cohort of chronic neck pain sufferers. Methods Sixty participants presenting to a private chiropractic clinic with chronic cervical pain as their primary complaint were sequentially allocated into treatment and control groups. Participants in the treatment group received a short course of Neuro Emotional Technique that consists of muscle testing, general semantics and Traditional Chinese Medicine. The control group received a sham NET protocol. Outcome measurements included pain assessment utilizing a visual analog scale and a pressure gauge algometer. Pain sensitivity was measured at four trigger point locations: suboccipital region (S); levator scapulae region (LS); sternocleidomastoid region (SCM) and temporomandibular region (TMJ). For each outcome measurement and each trigger point, we calculated the change in measurement between pre- and post- treatment. We then examined the relationships between these measurement changes and six independent variables (i.e. treatment group and the above five additional participant variables) using forward stepwise General Linear Model. Results The visual analog scale (0 to 10) had an improvement of 7.6 at S, 7.2 at LS, 7.5 at SCM and 7.1 at the TMJ in the treatment group compared with no improvement of at S, and an improvement of 0.04 at LS, 0.1 at SCM and 0.1 at the TMJ point in the control group, (P < 0.001). Conclusion After a short course of NET treatment, measurements of visual analog scale and pressure algometer recordings of four trigger point locations in a cohort of chronic neck pain sufferers were significantly improved when compared to a control group which received a sham protocol of NET. Chronic neck pain sufferers may benefit from NET treatment in the relief of trigger point sensitivity. Further research including long-term randomised controlled trials for the effect of NET on chronic neck pain, and other chronic pain syndromes are recommended. Trial Registration This trial has been registered and allocated the Australian Clinical Trials Registry (ACTR) number ACTRN012607000358448. The ACTR has met the requirements of the ICMJE's trials registration policy and is an ICMJE acceptable registry. PMID:18495042

Validation and Test-Retest Reliability of New Thermographic Technique Called Thermovision Technique of Dry Needling for Gluteus Minimus Trigger Points in Sciatica Subjects and TrPs-Negative Healthy Volunteers

PubMed Central

Rychlik, Michał; Samborski, Włodzimierz

2015-01-01

The aim of this study was to assess the validity and test-retest reliability of Thermovision Technique of Dry Needling (TTDN) for the gluteus minimus muscle. TTDN is a new thermography approach used to support trigger points (TrPs) diagnostic criteria by presence of short-term vasomotor reactions occurring in the area where TrPs refer pain. Method. Thirty chronic sciatica patients (n=15 TrP-positive and n=15 TrPs-negative) and 15 healthy volunteers were evaluated by TTDN three times during two consecutive days based on TrPs of the gluteus minimus muscle confirmed additionally by referred pain presence. TTDN employs average temperature (T avr), maximum temperature (T max), low/high isothermal-area, and autonomic referred pain phenomenon (AURP) that reflects vasodilatation/vasoconstriction. Validity and test-retest reliability were assessed concurrently. Results. Two components of TTDN validity and reliability, T avr and AURP, had almost perfect agreement according to κ (e.g., thigh: 0.880 and 0.938; calf: 0.902 and 0.956, resp.). The sensitivity for T avr, T max, AURP, and high isothermal-area was 100% for everyone, but specificity of 100% was for T avr and AURP only. Conclusion. TTDN is a valid and reliable method for T avr and AURP measurement to support TrPs diagnostic criteria for the gluteus minimus muscle when digitally evoked referred pain pattern is present. PMID:26137486

Changes in masseter muscle trigger points following strain-counterstrain or neuro-muscular technique.

PubMed

Ibáñez-García, Jordi; Alburquerque-Sendín, Francisco; Rodríguez-Blanco, Cleofás; Girao, Didac; Atienza-Meseguer, Albert; Planella-Abella, Sergi; Fernández-de-Las Peñas, César

2009-01-01

The aim of this study was to compare the immediate effects, on pressure pain sensitivity and active mouth opening, following the application of neuromuscular or strain/counter-strain technique in latent myofascial trigger points (MTrPs) in the masseter muscle. Seventy-one subjects, 34 men and 37 women, aged 20-65 years old, participated in this study. Subjects underwent a screening process to establish the presence of MTrPs in the masseter muscle. Subjects were divided randomly into three groups: group A which was treated with a neuromuscular intervention, group B treated with the strain/counter-strain technique, and group C as control group. Each treatment group received a weekly treatment session during 3 consecutive weeks. Outcomes measures were pressure pain thresholds (PPTs), active mouth opening and local pain (visual analogue scale, VAS) elicited by the application of 2.5kg/cm(2) of pressure over the MTrP. They were captured at baseline and 1 week after discharge by an assessor blinded to the treatment allocation of the subject. The ANOVA found a significant groupxtime interaction (F=25.3; p<0.001) for changes in PPT, changes in active mouth opening (F=10.5; p<0.001), and local pain evoked by 2.5kg/cm(2) of pressure (F=10.1; p<0.001). Within-group effect sizes were large (d>1) for PPT and mouth opening, and moderate for local pain (d<0.7, 0.5) in both intervention groups; but small (d<0.2) for the control group in all outcomes. No significant differences between both intervention groups were found for any outcome (p>0.8). Our results suggest that neuromuscular or strain/counter-strain technique might be employed in the management of latent MTrPs in the masseter muscle.

Effectiveness of Physical Therapy in Patients with Tension-type Headache: Literature Review.

PubMed

Espí-López, Gemma Victoria; Arnal-Gómez, Anna; Arbós-Berenguer, Teresa; González, Ángel Arturo López; Vicente-Herrero, Teófila

2014-01-01

Tension-type headache (TTH) is a disease with a great incidence on quality of life and with a significant socioeconomic impact. The aim of this review is to determine the effectiveness of physical therapy by using manual therapy (MT) for the relief of TTH. A review was done identifying randomized controlled trials through searches in MEDLINE, PEDro, Cochrane and CINAHL (January 2002 - April 2012). English-language studies, with adult patients and number of subjects not under 11, diagnosed with episodic tension-type headache (ETTH) and chronic tension-type headache (CTTH) were included. Initial search was undertaken with the words Effectiveness, Tension-type headache, and Manual therapy (39 studies). In addition, a search which included terms related to treatments such as physiotherapy, physical therapy, spinal manipulation was performed (25 studies). From the two searches 9 studies met the inclusion criteria and were analysed finding statistically significant results: 1) myofascial release, cervical traction, neck muscles trigger points in cervical thoracic muscles and stretching; 2) Superficial heat and massage, connective tissue manipulation and vertebral Cyriax mobilization; 3) cervical or thoracic spinal manipulation and cervical chin-occipital manual traction; 4) massage, progressive relaxation and gentle stretching, program of active exercises of shoulder, neck and pericranial muscles; 5) massage, passive rhythmic mobilization techniques, cervical, thoracic and lumbopelvic postural correction and cranio-cervical exercises; 6) progressive muscular relaxation combined with joint mobilization, functional, muscle energy, and strain/counterstrain techniques, and cranial osteopathic treatment; 7) massage focused on relieving myofascial trigger point activity; 8) pressure release and muscle energy in suboccipital muscles; 9) combination of mobilizations of the cervical and thoracic spine, exercises and postural correction. All studies used a combination of different techniques and none analyzed treatments separately, also all the studies have assessed aspects related to TTH beyond frequency and intensity of pain. The findings from these studies showed evidence that physiotherapy with articulatory MT, combined with cervical muscle stretching and massage are effective for this disease in different aspects related with TTH. No evidence was found of the effectiveness of the techniques applied separately.

Reproduction of overall spontaneous pain pattern by manual stimulation of active myofascial trigger points in fibromyalgia patients

PubMed Central

2011-01-01

Introduction It has previously been reported that local and referred pain from active myofascial trigger points (MTPs) in the neck and shoulder region contribute to fibromyalgia (FM) pain and that the pain pattern induced from active MTPs can reproduce parts of the spontaneous clinical FM pain pattern. The current study investigated whether the overall spontaneous FM pain pattern can be reproduced by local and referred pain from active MTPs located in different muscles. Methods A spontaneous pain pattern in FM was recorded in 30 FM patients and 30 healthy subjects served as controls. Local and referred pain patterns induced from active (patients) and latent (controls) MTPs were recorded following manual stimulation. The existence of MTPs was confirmed by intramuscular electromyographical registration of spontaneous electrical activity. Results Local and referred pain areas induced from key active MTPs in FM were larger than pain areas from latent MTPs in healthy controls (P < 0.001), but were similar to the overall spontaneous FM pain area in FM (P > 0.05). The induced pain area was positively associated with current spontaneous pain intensity in FM (P < 0.01). The locations of key active MTPs in FM patients were found to have latent MTPs in healthy subjects. The muscles containing key active MTPs in FM are often observed in the muscles of extensor digitorum, trapezius, infraspinatus in the upper part of the body and of quadratus lumborum, gluteus medius in the lower part of the body. Conclusions The overall spontaneous FM pain pattern can be reproduced by mechanical stimulation of active MTPs located in different muscles, suggesting that fibromyalgia pain is largely composed of pain arising from muscle pain and spasm. Targeting active MTPs and related perpetuating factors may be an important strategy in FM pain control. Trial registration ISRCTN ISRCTN43167547. PMID:21426569

Prevalence of myofascial trigger points in fibromyalgia: the overlap of two common problems.

PubMed

Ge, Hong-You

2010-10-01

With the objective evidence of their existence, myofascial trigger points (MTrPs) contribute to an increasing number of chronic regional and widespread pain conditions. The widespread spontaneous pain pattern in fibromyalgia (FM) is a summation of multiple regional pains due to active MTrPs. A regional pain in FM is from local active MTrPs and/or referred from remote active MTrPs. Positive tender points specified in FM are MTrPs, either active or latent. Manual stimulation of active MTrPs located in the muscles in different body regions completely reproduced overall spontaneous FM pain pattern. Active MTrPs as tonic peripheral nociceptive input contribute tremendously to the initiation and maintenance of central sensitization, to the impairment of descending inhibition, to the increased excitability of motor units, and to the induction of sympathetic hyperactivity observed in FM. The considerable overlap of MTrPs and FM in pain characteristics and pathophysiology suggests that FM pain is largely due to MTrPs.

Referred pain from myofascial trigger points in head, neck, shoulder, and arm muscles reproduces pain symptoms in blue-collar (manual) and white-collar (office) workers.

PubMed

Fernández-de-las-Peñas, César; Gröbli, Christian; Ortega-Santiago, Ricardo; Fischer, Christine Stebler; Boesch, Daniel; Froidevaux, Philippe; Stocker, Lilian; Weissmann, Richard; González-Iglesias, Javier

2012-07-01

To describe the prevalence and referred pain area of trigger points (TrPs) in blue-collar (manual) and white-collar (office) workers, and to analyze if the referred pain pattern elicited from TrPs completely reproduces the overall spontaneous pain pattern. Sixteen (62% women) blue-collar and 19 (75% women) white-collar workers were included in this study. TrPs in the temporalis, masseter, upper trapezius, sternocleidomastoid, splenius capitis, oblique capitis inferior, levator scapulae, scalene, pectoralis major, deltoid, infraspinatus, extensor carpi radialis brevis and longus, extensor digitorum communis, and supinator muscles were examined bilaterally (hyper-sensible tender spot within a palpable taut band, local twitch response with snapping palpation, and elicited referred pain pattern with palpation) by experienced assessors blinded to the participants' condition. TrPs were considered active when the local and referred pain reproduced any symptom and the patient recognized the pain as familiar. The referred pain areas were drawn on anatomic maps, digitized, and measured. Blue-collar workers had a mean of 6 (SD: 3) active and 10 (SD: 5) latent TrPs, whereas white-collar workers had a mean of 6 (SD: 4) active and 11 (SD: 6) latent TrPs (P>0.548). No significant differences in the distribution of active and latent TrPs in the analyzed muscles between groups were found. Active TrPs in the upper trapezius, infraspinatus, levator scapulae, and extensor carpi radialis brevis muscles were the most prevalent in both groups. Significant differences in referred pain areas between muscles (P<0.001) were found; pectoralis major, infraspinatus, upper trapezius, and scalene muscles showed the largest referred pain areas (P<0.01), whereas the temporalis, masseter, and splenius capitis muscles showed the smallest (P<0.05). The combination of the referred pain from TrPs reproduced the overall clinical pain area in all participants. Blue-collar and white-collar workers exhibited a similar number of TrPs in the upper quadrant musculature. The referred pain elicited by active TrPs reproduced the overall pain pattern. The distribution of TrPs was not significantly different between groups. Clinicians should examine for the presence of muscle TrPs in blue-collar and white-collar workers.

The Location of Peak Upper Trapezius Muscle Activity During Submaximal Contractions is not Associated With the Location of Myofascial Trigger Points: New Insights Revealed by High-density Surface EMG.

PubMed

Barbero, Marco; Falla, Deborah; Mafodda, Luca; Cescon, Corrado; Gatti, Roberto

2016-12-01

To apply topographical mapping of the electromyography (EMG) amplitude recorded from the upper trapezius muscle to evaluate the distribution of activity and the location of peak activity during a shoulder elevation task in participants with and without myofascial pain and myofascial trigger points (MTrP) and compare this location with the site of the MTrP. Thirteen participants with myofascial pain and MTrP in the upper trapezius muscle and 12 asymptomatic individuals participated. High-density surface EMG was recorded from the upper trapezius muscle using a matrix of 64 surface electrodes aligned with an anatomic landmark system (ALS). Each participant performed a shoulder elevation task consisting of a series of 30 s ramped contractions to 15% or 60% of their maximal voluntary contraction (MVC) force. Topographical maps of the EMG average rectified value were computed and the peak EMG amplitude during the ramped contractions was identified and its location determined with respect to the ALS. The location of the MTrP was also determined relative to the ALS and Spearman correlation coefficients were used to examine the relationship between MTrP and peak EMG amplitude location. The location of the peak EMG amplitude was significantly (P<0.05) different between groups (participants with pain/MTrP: -0.32±1.2 cm at 15% MVC and -0.35±0.9 cm at 60% MVC relative to the ALS; asymptomatic participants: 1.0±1.3 cm at 15% MVC and 1.3±1.1 cm relative to the ALS). However, no correlation was observed between the position of the MTrP and peak EMG amplitude during the ramped contractions at either force level (15%: rs=0.039, P=0.9; 60%: rs=-0.087, P=0.778). People with myofascial pain and MTrP displayed a caudal shift of the distribution of upper trapezius muscle activity compared with asymptomatic individuals during a submaximal shoulder elevation task. For the first time, we show that the location of peak muscle activity is not associated with the location of the MTrP.

A technical report on ultrasound-guided scapulocostal syndrome injection.

PubMed

McCarthy, C; Harmon, D

2016-08-01

We describe a case report and technique for using an ultrasound scanner and a linear transducer to guide serratus posterior superior (SPS) muscle injection. A 43-year-old female presented with chronic pain centered under the right upper portion of her scapula impacting her activities of daily living. For the ultrasound-guided SPS muscle injection, the patient was placed in the prone position. The transducer was oriented in a transverse orientation at the level of the C6-T1 vertebrae. Here the SPS muscle attaches to the lower portion of the ligament nuchae and the intervening interspinous ligaments. The muscle fibers run inferiorly and laterally to attach to the 2nd-5th ribs which were identified along with the lateral portion of the serratus posterior superior muscle which is covered by the scapula. Real-time imaging was used to direct a spinal needle into the trigger points of the SPS muscle, where solution was injected under direct vision. The patient's pain symptoms improved significantly. Serratus posterior superior injection can confirm a diagnosis of scapulocostal syndrome and be therapeutically beneficial.

Effect of lidocaine patches on upper trapezius EMG activity and pain intensity in patients with myofascial trigger points: A randomized clinical study.

PubMed

Firmani, Mónica; Miralles, Rodolfo; Casassus, Rodrigo

2015-04-01

To compare the effects of 5% lidocaine patches and placebo patches on pain intensity and electromyographic (EMG) activity of an active myofascial trigger point (MTrP) of the upper trapezius muscle. Thirty-six patients with a MTrP in the upper trapezius muscle were randomly divided into two groups: 20 patients received lidocaine patches (lidocaine group) and 16 patients received placebo patches (placebo group). They used the patches for 12 h each day, for 2 weeks. The patch was applied to the skin over the upper trapezius MTrP. Spontaneous pain, pressure pain thresholds, pain provoked by a 4-kg pressure applied to the MTrP and trapezius EMG activity were measured before and after treatment. Baseline spontaneous pain values were similar in both groups and significantly lower in the lidocaine group than the placebo group after treatment. The baseline pressure pain threshold was significantly lower in the lidocaine group, but after treatment it was significantly higher in this group. Baseline and final values of the pain provoked by a 4-kg pressure showed no significant difference between the groups. Baseline EMG activity at rest and during swallowing of saliva was significantly higher in the lidocaine group, but no significant difference was observed after treatment. Baseline EMG activity during maximum voluntary clenching was similar in both groups, but significantly higher in the lidocaine group after treatment. These clinical and EMG results support the use of 5% lidocaine patches for treating patients with MTrP of the upper trapezius muscle.

Wet needling of myofascial trigger points in abdominal muscles for treatment of primary dysmenorrhoea.

PubMed

Huang, Qiang-Min; Liu, Lin

2014-08-01

To evaluate the effect of wet needling (related to acupuncture) and home stretching exercises on myofascial trigger points (MTrPs) in abdominal muscles for the treatment of dysmenorrhoea. The effect of wet needing of MTrPs in abdominal muscles, supplemented by home stretching exercises, was observed in 65 patients with moderate and severe primary dysmenorrhoea. The MTrPs in the abdominal region were localised and repeatedly needled with lidocaine injection. Menstrual pain was evaluated with a Visual Analogue Scale (VAS) score after every treatment, with the final evaluation made at a 1-year follow-up. Treatment was stopped when the VAS pain score reduced to ≤3. Symptoms scores were analysed with one-way analysis of variance. The mean VAS pain score before treatment was 7.49±1.16. After a single wet needling session, 41 patients had a reduction in their VAS pain score to <3 during their following menstrual cycle, with a mean of 1.63±0.49. Twenty-four patients who needed two treatments showed a reduction in menstrual pain scores to 0.58±0.50. After 1 year, the mean VAS pain score among all patients was 0.28±0.45, with a response rate of 100%. Primary dysmenorrhoea was significantly reduced 1 year after wet needling to MTrPs in the abdominal region and home stretching exercises, justifying further research with controlled trials. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Successful use of botulinum toxin type a in the treatment of refractory postoperative dyspareunia.

PubMed

Park, Amy J; Paraiso, Marie Fidela R

2009-08-01

Refractory dyspareunia presents a challenging therapeutic dilemma. A woman with defecatory dysfunction and dyspareunia presented with stage 2 prolapse. She underwent laparoscopic and vaginal pelvic floor reconstruction with excision of endometriosis. The patient experienced increased dyspareunia and de novo vaginismus postoperatively that were refractory to trigger point injections, physical therapy, and medical and surgical management. She underwent botulinum toxin type A injections into her levator ani muscles, which allowed her to have sexual intercourse again after 2 years of apareunia with no recurrence of pain for 12 months. Injecting botulinum toxin into the levator ani muscles shows promise for postoperative patients who develop vaginismus and do not respond to conservative therapy.

The local and referred pain from myofascial trigger points in the temporalis muscle contributes to pain profile in chronic tension-type headache.

PubMed

Fernández-de-Las-Peñas, César; Ge, Hong-You; Arendt-Nielsen, Lars; Cuadrado, Maria Luz; Pareja, Juan A

2007-01-01

To assess the local and referred pain areas and pain characteristics evoked from temporalis muscle trigger points (TrPs) in chronic tension-type headache (CTTH). Thirty CTTH patients and 30 age and sex-matched controls were studied. A headache diary was kept for 4 weeks to substantiate the diagnosis and record the pain history. Both temporalis muscles were examined for the presence of myofascial TrPs in a blinded fashion. The local and referred pain intensities, referred pain pattern, and pressure pain threshold were recorded. Referred pain was evoked in 87% and 54% on the dominant and nondominant sides in CTTH patients, which was significantly higher (P<0.001) than in controls (10% vs. 17%, respectively). Referred pain spread to the temple ipsilateral to the stimulated muscle in both patients and controls, with additional referral behind the eyes in most patients, but none in controls. CTTH patients reported a higher local [visual analog scale (VAS): 5.6+/-1.2 right side, 5.3+/-1.4 left side] and referred pain (VAS: 4.7+/-2 right side, 3.5+/-2.8 left side) intensity than healthy controls (VAS: 0.8+/-0.7 right side, 0.7+/-0.7 left side for local pain; and 0.3+/-0.2 right side, 0.4+/-0.3 left side for referred pain) in both temporalis muscles (both, P<0.001). The local and referred pain areas were larger in patients than in controls (P<0.001). Twenty-three out of 30 CTTH patients (77%) had active TrPs in the temporalis muscle leading to their usual headache (17 patients on the right side; 12 on the left side, whereas 6 with bilateral active TrPs). CTTH patients with active TrPs in either right or left temporalis muscle showed longer headache duration than those with latent TrPs (P=0.004). CTTH patients showed significantly (P<0.001) lower pressure pain threshold (1.1+/-0.2 right side, 1.2+/-0.3 left side) as compared with controls (2.5+/-0.5 right side, 2.6+/-0.4 left side). In CTTH patients, the evoked local and referred pain from active TrPs in the temporalis muscle and its sensory characteristics shared similar patterns as their habitual headache pain. Local and referred pain from active TrPs in the temporalis muscles may constitute one of the sources contributing to the pain profile of CTTH.

High prevalence of shoulder girdle muscles with myofascial trigger points in patients with shoulder pain

PubMed Central

2011-01-01

Background Shoulder pain is reported to be highly prevalent and tends to be recurrent or persistent despite medical treatment. The pathophysiological mechanisms of shoulder pain are poorly understood. Furthermore, there is little evidence supporting the effectiveness of current treatment protocols. Although myofascial trigger points (MTrPs) are rarely mentioned in relation to shoulder pain, they may present an alternative underlying mechanism, which would provide new treatment targets through MTrP inactivation. While previous research has demonstrated that trained physiotherapists can reliably identify MTrPs in patients with shoulder pain, the percentage of patients who actually have MTrPs remains unclear. The aim of this observational study was to assess the prevalence of muscles with MTrPs and the association between MTrPs and the severity of pain and functioning in patients with chronic non-traumatic unilateral shoulder pain. Methods An observational study was conducted. Subjects were recruited from patients participating in a controlled trial studying the effectiveness of physical therapy on patients with unilateral non-traumatic shoulder pain. Sociodemographic and patient-reported symptom scores, including the Disabilities of the Arm, Shoulder, and Hand (DASH) Questionnaire, and Visual Analogue Scales for Pain were compared with other studies. To test for differences in age, gender distribution, and education level between the current study population and the populations from Dutch shoulder studies, the one sample T-test was used. One observer examined all subjects (n = 72) for the presence of MTrPs. Frequency distributions, means, medians, standard deviations, and 95% confidence intervals were calculated for descriptive purposes. The Spearman's rank-order correlation (ρ) was used to test for association between variables. Results MTrPs were identified in all subjects. The median number of muscles with MTrPs per subject was 6 (active MTrPs) and 4 (latent MTrPs). Active MTrPs were most prevalent in the infraspinatus (77%) and the upper trapezius muscles (58%), whereas latent MTrPs were most prevalent in the teres major (49%) and anterior deltoid muscles (38%). The number of muscles with active MTrPs was only moderately correlated with the DASH score. Conclusion The prevalence of muscles containing active and latent MTrPs in a sample of patients with chronic non-traumatic shoulder pain was high. PMID:21711512

Coherence between tissue oxygen indexes in vastus lateralis and gastrocnemius in repetition of impulse exercise with high intensity.

PubMed

Yano, T; Widjaja, W; Shirakawa, K; Lian, C-S; Xiao, Z; Yunoki, T

2015-06-01

The purpose of this study was to determine whether tissue oxygen indices (TOIs) in two muscle groups oscillated and were synchronized in repetition of impulse exercise with high intensity. Five impulse exercises of 400 watts for 10 s were repeated with intervals of 6 min. During this period, TOI was determined by near-infrared spectroscopy in the vastus lateralis and gastrocnemius muscles. TOIs in the two muscles oscillated at rest. The TOIs rapidly decreased during each impulse exercise and then recovered and overshot after each impulse. The TOIs oscillated during each interval period. During this test period, coherent and phase differences were determined. There was high coherence between TOIs in the two muscles with a peak value at 0.019 Hz. There was a phase difference of -45 ± 32.4 degrees between TOIs in the two muscles. This phase difference corresponded to about 6 s in time scale. It seemed from this time delay that impulse exercise was not a trigger factor for the starting point of TOIs in the two muscles. It has been concluded that TOIs oscillate and are synchronized between two muscles in repetition of impulse exercise with high intensity.

The relationship between latent trigger points and depression levels in healthy subjects.

PubMed

Celik, Derya; Kaya Mutlu, Ebru

2012-06-01

Our purpose was to study the relationship between latent trigger points (LTrP) and levels of depression in healthy subjects. A total of 76 healthy subjects consisting of 40 men and 36 women (mean age, 25.4 ± 4.8 years; age range, 19-42 years) from the School of Physical Therapy and Rehabilitation and the Orthopaedics and Traumatology Department of Istanbul University Medical Faculty were selected for the study. Latent trigger points on the scapular muscles of each subject were evaluated. The upper and middle trapezius, supraspinatus, serratus anterior, and rhomboideus muscles were examined respectively, by palpation with the thumb, to determine whether there was pain. The first group consisted of 30 subjects (20 men and 10 women; mean age, 24.2 ± 5.02 years) who had previously been diagnosed as negative after an LTrP examination (control group), while the second group consisted of 28 subjects (12 men and 16 women; mean age, 23.6 ± 2.24 years) who had been diagnosed with at least five LTrPs. The third group consisted of 18 subjects (8 men and 10 women; mean age, 26. 9 ± 7.23 years) who had been diagnosed with more than five LTrPs. All groups were assessed, using the Beck Depression Inventory (BDI). The mean BDI value was found to be 8.0 ± 4.2 in the first group, 10.3 ± 3.4 in the second, and 28.5 ± 4.8 in the third. A significant difference was found between the mean BDI values of the first and second groups and also between the first and third groups. The mean BDI values of the second and third groups were also found to be statistically significant (p = 0.042). We observed a close relationship between the presence of LTrPs and depression levels in healthy people.

Triggered intravoxel incoherent motion MRI for the assessment of calf muscle perfusion during isometric intermittent exercise.

PubMed

Mastropietro, Alfonso; Porcelli, Simone; Cadioli, Marcello; Rasica, Letizia; Scalco, Elisa; Gerevini, Simonetta; Marzorati, Mauro; Rizzo, Giovanna

2018-06-01

The main aim of this paper was to propose triggered intravoxel incoherent motion (IVIM) imaging sequences for the evaluation of perfusion changes in calf muscles before, during and after isometric intermittent exercise. Twelve healthy volunteers were involved in the study. The subjects were asked to perform intermittent isometric plantar flexions inside the MRI bore. MRI of the calf muscles was performed on a 3.0 T scanner and diffusion-weighted (DW) images were obtained using eight different b values (0 to 500 s/mm 2 ). Acquisitions were performed at rest, during exercise and in the subsequent recovery phase. A motion-triggered echo-planar imaging DW sequence was implemented to avoid movement artifacts. Image quality was evaluated using the average edge strength (AES) as a quantitative metric to assess the motion artifact effect. IVIM parameters (diffusion D, perfusion fraction f and pseudo-diffusion D*) were estimated using a segmented fitting approach and evaluated in gastrocnemius and soleus muscles. No differences were observed in quality of IVIM images between resting state and triggered exercise, whereas the non-triggered images acquired during exercise had a significantly lower value of AES (reduction of more than 20%). The isometric intermittent plantar-flexion exercise induced an increase of all IVIM parameters (D by 10%; f by 90%; D* by 124%; fD* by 260%), in agreement with the increased muscle perfusion occurring during exercise. Finally, IVIM parameters reverted to the resting values within 3 min during the recovery phase. In conclusion, the IVIM approach, if properly adapted using motion-triggered sequences, seems to be a promising method to investigate muscle perfusion during isometric exercise. Copyright © 2018 John Wiley & Sons, Ltd.

Surgical fasciectomy of the trapezius muscle combined with neurolysis of the Spinal accessory nerve; results and long-term follow-up in 30 consecutive cases of refractory chronic whiplash syndrome

PubMed Central

2010-01-01

Background Chronic problems from whiplash trauma generally include headache, pain and neck stiffness that may prove refractory to conservative treatment modalities. As has previously been reported, such afflicted patients may experience significant temporary relief with injections of local anesthetic to painful trigger points in muscles of the shoulder and neck, or lasting symptomatic improvement through surgical excision of myofascial trigger points. In a subset of patients who present with chronic whiplash syndrome, the clinical findings suggest an affliction of the spinal accessory nerve (CN XI, SAN) by entrapment under the fascia of the trapezius muscle. The present study was undertaken to assess the effectiveness of SAN neurolysis in chronic whiplash syndrome. Methods A standardized questionnaire and a linear visual-analogue scale graded 0-10 was used to assess disability related to five symptoms (pain, headache, insomnia, weakness, and stiffness) before, and one year after surgery in a series of thirty consecutive patients. Results The preoperative duration of symptoms ranged from seven months to 13 years. The following changes in disability scores were documented one year after surgery: Overall pain decreased from 9.5 +/- 0.9 to 3.2 +/- 2.6 (p < 0.001); headaches from 8.2 +/- 2.9 to 2.3 +/- 2.8 (p < 0.001); insomnia from 7.5 +/- 2.4 to 3.8 +/- 2.8 (p < 0.001); weakness from 7.6 +/- 2.6 to 3.6 +/- 2.8 (p < 0.001); and stiffness from 7.0 +/- 3.2 to 2.6 +/- 2.7 (p < 0.001). Conclusions Entrapment of the spinal accessory nerve and/or chronic compartment syndrome of the trapezius muscle may cause chronic debilitating pain after whiplash trauma, without radiological or electrodiagnostic evidence of injury. In such cases, surgical treatment may provide lasting relief. PMID:20374624

Referred pain from myofascial trigger points in head and neck-shoulder muscles reproduces head pain features in children with chronic tension type headache.

PubMed

Fernández-de-las-Peñas, César; Fernández-Mayoralas, Daniel M; Ortega-Santiago, Ricardo; Ambite-Quesada, Silvia; Palacios-Ceña, Domingo; Pareja, Juan A

2011-02-01

Our aim was to describe the referred pain pattern and areas from trigger points (TrPs) in head, neck, and shoulder muscles in children with chronic tension type headache (CTTH). Fifty children (14 boys, 36 girls, mean age: 8 ± 2) with CTTH and 50 age- and sex- matched children participated. Bilateral temporalis, masseter, superior oblique, upper trapezius, sternocleidomastoid, suboccipital, and levator scapula muscles were examined for TrPs by an assessor blinded to the children's condition. TrPs were identified with palpation and considered active when local and referred pains reproduce headache pain attacks. The referred pain areas were drawn on anatomical maps, digitalized, and also measured. The total number of TrPs was significantly greater in children with CTTH as compared to healthy children (P < 0.001). Active TrPs were only present in children with CTTH (P < 0.001). Within children with CTTH, a significant positive association between the number of active TrPs and headache duration (r (s) = 0.315; P = 0.026) was observed: the greater the number of active TrPs, the longer the duration of headache attack. Significant differences in referred pain areas between groups (P < 0.001) and muscles (P < 0.001) were found: the referred pain areas were larger in CTTH children (P < 0.001), and the referred pain area elicited by suboccipital TrPs was larger than the referred pain from the remaining TrPs (P < 0.001). Significant positive correlations between some headache clinical parameters and the size of the referred pain area were found. Our results showed that the local and referred pains elicited from active TrPs in head, neck and shoulder shared similar pain pattern as spontaneous CTTH in children, supporting a relevant role of active TrPs in CTTH in children.

Intensive short-term vasodilation effect in the pain area of sciatica patients--case study.

PubMed

Skorupska, Elżbieta; Rychlik, Michał; Pawelec, Wiktoria; Bednarek, Agata; Samborski, Włodzimierz

2014-09-09

Varied and complicated etiology of low back pain radiating distally to the extremities is still causing disagreement and controversy around the issue of its diagnosis and treatment. Most clinicians believe that the source of that pain is generally radicular. While some of them postulate the clinical significance of the sacroiliac joint syndrome, others demonstrate that almost one in five people with back pain experience symptoms indicative of the neuropathic pain component. To date, neuropathic involvement has not been completely understood, and different mechanisms are thought to play an important role. It has been established that muscle pain (myofascial pain) e.g. active trigger points from the gluteus minimus, can mimic pain similar to sciatica, especially in the chronic stage. This paper describes patients presenting with radicular sciatica (case one and two) and sciatica-like symptoms (case three). For the first time, intensive short-term vasodilation in the pain area following needle infiltration of the gluteus minimus trigger point was recorded. Three Caucasian, European women suffering from radicular sciatica (case one and two) and sciatica-like symptoms (case three) at the age of 57, 49 and 47 respectively underwent infrared camera observation during needle infiltration of the gluteus minimus trigger point. The patients were diagnosed by a neurologist; they underwent magnetic resonance imaging, electromyography, neurography and blood test analysis. Apart from that, the patients were diagnosed by a clinician specializing in myofascial pain diagnosis. In the examined cases, trigger points-related short-term vasodilation was recorded. Confirmation of these findings in a controlled, blinded study would indicate the existence of a link between the pain of sciatica patients (radicular or sciatica-like pain) and the activity of the autonomic nervous system. Further studies on a bigger group of patients are still needed.

Laryngeal reinnervation for bilateral vocal fold paralysis.

PubMed

Marina, Mat B; Marie, Jean-Paul; Birchall, Martin A

2011-12-01

Laryngeal reinnervation for bilateral vocal fold paralysis (BVFP) patients is a promising technique to achieve good airway, although preserving a good quality of voice. On the other hand, the procedure is not simple. This review explores the recent literature on surgical technique and factors that may contribute to the success. Research and literature in this area are limited due to variability and complexity of the nerve supply. The posterior cricoarytenoid (PCA) muscle also receives nerve supply from the interarytenoid branch. Transection of this nerve at the point between interarytenoid and PCA branch may prevent aberrant reinnervation of adductor nerve axons to the PCA muscle. A varying degree of regeneration of injured recurrent laryngeal nerves (RLN) in humans of more than 6 months confirms subclinical reinnervation, which may prevent denervation-induced atrophy. Several promising surgical techniques have been developed for bilateral selective reinnervation for BVFP patients. This involves reinnervation of the abductor and adductor laryngeal muscles. The surgical technique aims at reinnervating the PCA muscle to trigger abduction during the respiratory cycle and preservation of good voice by strengthening the adductor muscles as well as prevention of laryngeal synkinesis.

Amygdala Lesions Reduce Cataplexy in Orexin KO mice

PubMed Central

Burgess, C.R.; Oishi, Y.; Mochizuki, T.; Peever, J.H.; Scammell, T.E.

2013-01-01

Narcolepsy is characterized by excessive sleepiness and cataplexy, sudden episodes of muscle weakness during waking that are thought to be an intrusion of REM sleep muscle atonia into wakefulness. One of the most striking aspects of cataplexy is that it is often triggered by strong, generally positive emotions, but little is known about the neural pathways through which positive emotions trigger muscle atonia. We hypothesized that the amygdala is functionally important for cataplexy because the amygdala has a role in processing emotional stimuli and it contains neurons that are active during cataplexy. Using anterograde and retrograde tracing in mice, we found that GABAergic neurons in the central nucleus of the amygdala heavily innervate neurons that maintain waking muscle tone such as those in the ventrolateral periaqueductal grey, lateral pontine tegmentum, locus coeruleus, and dorsal raphe. We then found that bilateral, excitotoxic lesions of the amygdala markedly reduced cataplexy in orexin knockout mice, a model of narcolepsy. These lesions did not alter basic sleep/wake behavior, but substantially reduced the triggering of cataplexy. Lesions also reduced the cataplexy events triggered by conditions associated with high arousal and positive emotions (i.e., wheel running and chocolate). These observations demonstrate that the amygdala is a functionally important part of the circuitry underlying cataplexy and suggest that increased amygdala activity in response to emotional stimuli could directly trigger cataplexy by inhibiting brainstem regions that suppress muscle atonia. PMID:23739970

Amygdala lesions reduce cataplexy in orexin knock-out mice.

PubMed

Burgess, Christian R; Oishi, Yo; Mochizuki, Takatoshi; Peever, John H; Scammell, Thomas E

2013-06-05

Narcolepsy is characterized by excessive sleepiness and cataplexy, sudden episodes of muscle weakness during waking that are thought to be an intrusion of rapid eye movement sleep muscle atonia into wakefulness. One of the most striking aspects of cataplexy is that it is often triggered by strong, generally positive emotions, but little is known about the neural pathways through which positive emotions trigger muscle atonia. We hypothesized that the amygdala is functionally important for cataplexy because the amygdala has a role in processing emotional stimuli and it contains neurons that are active during cataplexy. Using anterograde and retrograde tracing in mice, we found that GABAergic neurons in the central nucleus of the amygdala heavily innervate neurons that maintain waking muscle tone such as those in the ventrolateral periaqueductal gray, lateral pontine tegmentum, locus ceruleus, and dorsal raphe. We then found that bilateral, excitotoxic lesions of the amygdala markedly reduced cataplexy in orexin knock-out mice, a model of narcolepsy. These lesions did not alter basic sleep-wake behavior but substantially reduced the triggering of cataplexy. Lesions also reduced the cataplexy events triggered by conditions associated with high arousal and positive emotions (i.e., wheel running and chocolate). These observations demonstrate that the amygdala is a functionally important part of the circuitry underlying cataplexy and suggest that increased amygdala activity in response to emotional stimuli could directly trigger cataplexy by inhibiting brainstem regions that suppress muscle atonia.

The effects of KinesioTape on the treatment of lateral epicondylitis.

PubMed

Shakeri, Hassan; Soleimanifar, Manijeh; Arab, A M; Hamneshin Behbahani, Shirin

Randomized clinical trial. KinesioTape (KT) is a noninvasive method to treat pain and muscular dysfunction. To investigate the effect of KT with and without tension on pain intensity, pain pressure threshold, grip strength and disability in individuals with lateral epicondylitis, and myofacial trigger points in forearm muscles. Thirty women with lateral epicondylitis and myofacial trigger point in forearm muscles were randomly assigned to KT with tension and placebo (KT without tension). The treatment was provided 3 times in one week, and outcome measures were assess pre-post treatment. The mean score of visual analogue scale (VAS) during activity decreased significantly from 6.4 and 6 pretest to 2.53 and 4.66 posttest, respectively, for the KT with and without tension groups. The mean score of Disabilities of the Arm, Shoulder and Hand decreased significantly from 16.82 and 22.79 pretest to 8.65 and 8.29 posttest, respectively, for the KT with and without tension groups. A paired t-test revealed a significant reduction in VAS during activity and Disabilities of the Arm, Shoulder and Hand before and after treatment in both groups (P < .05). Pain pressure threshold, grip strength, and VAS using an algometer revealed no significant differences. The study showed no significant difference in variables immediately after intervention. Improvements in functional disability were superior when KT was used with tension, than obtained with a placebo-no tension application. The application of KT produces an improvement in pain intensity and upper extremity disability in subjects with LE and MTP in forearm muscles, and KT with tension was more effective than placebo group. NA. 100-216. Copyright © 2017 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

Improvement in clinical outcomes after dry needling versus myofascial release on pain pressure thresholds, quality of life, fatigue, pain intensity, quality of sleep, anxiety, and depression in patients with fibromyalgia syndrome.

PubMed

Castro Sánchez, Adelaida M; García López, Hector; Fernández Sánchez, Manuel; Pérez Mármol, José Manuel; Aguilar-Ferrándiz, María Encarnación; Luque Suárez, Alejandro; Matarán Peñarrocha, Guillermo Adolfo

2018-04-23

To compare the effectiveness of dry needling versus myofascial release on myofascial trigger points pain in cervical muscles, quality of life, impact of symptoms pain, quality of sleep, anxiety, depression, and fatigue in patients with fibromyalgia syndrome. A single-blind randomized controlled trial was conducted. Sixty-four subjects with fibromyalgia were randomly assigned to a dry needling group or a myofascial release group. Pain pressure thresholds of myofascial trigger points were evaluated in the cervical muscles. In addition, quality of life, impact of fibromyalgia symptoms, quality of sleep, intensity of pain, anxiety and depression symptoms, impact of fatigue at baseline and post treatment after four weeks of intervention were evaluated. Significant improvement was found in most pain pressure thresholds of the myofascial trigger points in cervical muscles in the dry needling group compared to myofascial release (p < 0.05). Similarly, these differences between groups were found for the components of quality of life of physical function (F = 12.74, p = 0.001), physical role (F = 11.24, p = 0.001), body pain (F =30.26, p < 0.001), general health (F = 15.83, p < 0.001), vitality (F = 13.51, p = 0.001), social function (F = 4.73, p = 0.034), emotional role (F = 8.01, p = 0.006), and mental health (F = 4.95, p = 0.030). Similar results were achieved for total impact of FMS symptoms (F = 42.91, p < 0.001), quality of sleep (F = 11.96, p = 0.001), state anxiety (F = 7.40, p = 0.009), and trait anxiety (F = -14.63, p < 0.001), hospital anxiety and depression (F = 20.60, p < 0.001), general pain intensity (F = 29.59, p < 0.001), and fatigue (F = -25.73, p < 0.001). The dry needling therapy showed higher improvements in comparison with myofascial release therapy for pain pressure thresholds, the components of quality of life of physical role, body pain, vitality and social function, as well as the total impact of FMS symptoms, quality of sleep, state and trait anxiety, hospital anxiety-depression, general pain intensity and fatigue. Implications for rehabilitation Dry needling therapy reduces myofascial trigger point pain in the short term in patients with fibromyalgia syndrome. This therapeutic approach improves anxiety, depression, fatigue symptoms, quality of life, and sleep after treatment. Dry needling and myofascial release therapies decrease intensity of pain, and the impact of fibromyalgia symptoms in this population. These intervention approaches should be considered in an independent manner as complementary therapies within a multidisciplinary setting.

Development of a clinical prediction rule for identifying women with tension-type headache who are likely to achieve short-term success with joint mobilization and muscle trigger point therapy.

PubMed

Fernández-de-las-Peñas, César; Cleland, Joshua A; Palomeque-del-Cerro, Luis; Caminero, Ana Belén; Guillem-Mesado, Amparo; Jiménez-García, Rodrigo

2011-02-01

To identify prognostic factors from the history and physical examination in women with tension-type headache (TTH) who are likely to experience self-perceived clinical improvement following a multimodal physical therapy session including joint mobilization and muscle trigger point (TrP) therapies. No definitive therapeutic intervention is available for TTH. It would be useful for clinicians to have a clinical prediction rule for selecting which TTH patients may experience improved outcomes following a multimodal physical therapy program. Women diagnosed with pure TTH by 3 experienced neurologists according to the International Headache Society criteria from different neurology departments were included. They underwent a standardized examination (neck mobility, pressure pain thresholds, total tenderness score, presence of muscle TrPs, Medical Outcomes Study 36-Item Short Form, the Neck Disability Index [NDI], the Beck Depression Inventory, and the Headache Disability Inventory) and then a multimodal physical therapy session including joint mobilization and TrP therapies. The treatment session included a 30-second grade III or IV central posterior-anterior nonthrust mobilization applied from T4 to T1 thoracic vertebrae, at C7-T1 cervico-thoracic junction and C1-C2 vertebrae for an overall intervention time of 5 minutes Different TrP techniques, particularly soft tissue stroke, pressure release, or muscle energy were applied to head and neck-shoulder muscles (temporalis, suboccipital, upper trapezius, splenius capitis, semispinalis capitis, sternocleidomastoid) to inactivate active muscle TrPs. Participants were classified as having achieved a successful outcome 1 week after the session based on their self-perceived recovery. Potential prognostic variables were entered into a stepwise logistic regression model to determine the most accurate set of variables for prediction of success. Data for 76 subjects were included in the analysis, of which 36 experienced a successful outcome (48%). Eight prognostic variables were retained in the regression model: mean age <44.5 years, presence of left sternocleidomastoid TrP, presence of suboccipital TrP, presence of left superior oblique muscle TrP, cervical rotation to the left > 69°, total tenderness score <20.5, NDI <18.5, referred pain area of right upper trapezius muscle TrP >42.23. The current clinical prediction rule may allow clinicians to make an a priori identification of women with TTH who are likely to experience short-term self-report improvement with a multimodal session including joint mobilizations and TrP therapies. Future studies are necessary to validate these findings. © 2010 American Headache Society.

The effects of electromyography-triggered electrical stimulation on shoulder subluxation, muscle activation, pain, and function in persons with stroke: A pilot study.

PubMed

Jeon, Somyung; Kim, Young; Jung, Kyoungsim; Chung, Yijung

2017-01-01

The purpose of this study was to examine the effects of task-oriented electromyography-triggered stimulation for shoulder subluxation, muscle activation, pain and upper extremity function in hemiparetic stroke patients. Twenty participants with subacute hemiparetic stroke were recruited for this study and were randomly divided into two groups: experimental group (n = 10) and control group (n = 10). Subjects in the experimental group participated in task-oriented electromyography triggered stimulation for 30 minutes, five times a week for four weeks, whereas the control group received cyclic functional electrical stimulation for 30 minutes, five times a week for four weeks. Subjects in both groups received conventional physical therapy for four weeks (30 min/day, five times/week). Data collected included the degree of shoulder subluxation which had been confirmed by X-ray, muscle activation of the supraspinatus and posterior deltoid muscles by electromyography, pain by the Visual Analogue Scale (VAS), and hand function by the Fugl-Meyer Assessment (FMA) before and after the four week exercise period. The results showed significant improvement in shoulder subluxation, muscle activation, and VAS results in the experimental group, compared with the control group(p < 0.05). FMA scores showed no significant differences between the two groups. In conclusion, task-oriented electromyography-triggered stimulation improved shoulder subluxation, muscle activation, pain and upper extremity function. These results suggest that task-oriented electromyography-triggered stimulation is effective and beneficial for individuals with subacute stroke, and that further studies should be conducted on multivarious anatomical regions.

Treatment of myofascial trigger points in patients with chronic shoulder pain: a randomized, controlled trial

PubMed Central

2011-01-01

Background Shoulder pain is a common musculoskeletal problem that is often chronic or recurrent. Myofascial trigger points (MTrPs) cause shoulder pain and are prevalent in patients with shoulder pain. However, few studies have focused on MTrP therapy. The aim of this study was to assess the effectiveness of multimodal treatment of MTrPs in patients with chronic shoulder pain. Methods A single-assessor, blinded, randomized, controlled trial was conducted. The intervention group received comprehensive treatment once weekly consisting of manual compression of the MTrPs, manual stretching of the muscles and intermittent cold application with stretching. Patients were instructed to perform muscle-stretching and relaxation exercises at home and received ergonomic recommendations and advice to assume and maintain good posture. The control group remained on the waiting list for 3 months. The Disabilities of Arm, Shoulder and Hand (DASH) questionnaire score (primary outcome), Visual Analogue Scale for Pain (VAS-P), Global Perceived Effect (GPE) scale and the number of muscles with MTrPs were assessed at 6 and 12 weeks in the intervention group and compared with those of a control group. Results Compared with the control group, the intervention group showed significant improvement (P < 0.05) on the DASH after 12 weeks (mean difference, 7.7; 95% confidence interval (95% CI), 1.2 to 14.2), on the VAS-P1 for current pain (mean difference, 13.8; 95% CI, 2.6 to 25.0), on the VAS-P2 for pain in the past 7 days (mean difference, 10.2; 95% CI, 0.7 to 19.7) and VAS-P3 most severe pain in the past 7 days (mean difference, 13.8; 95% CI, 0.8 to 28.4). After 12 weeks, 55% of the patients in the intervention group reported improvement (from slightly improved to completely recovered) versus 14% in the control group. The mean number of muscles with active MTrPs decreased in the intervention group compared with the control group (mean difference, 2.7; 95% CI, 1.2 to 4.2). Conclusions The results of this study show that 12-week comprehensive treatment of MTrPs in shoulder muscles reduces the number of muscles with active MTrPs and is effective in reducing symptoms and improving shoulder function in patients with chronic shoulder pain. Trial registration number ISRCTN: ISRCTN75722066 PMID:21261971

Role of Innate Immunity in a Model of Histidyl-tRNA Synthetase (Jo-1)-mediated Myositis

PubMed Central

Soejima, Makoto; Kang, Eun Ha; Gu, Xinyan; Katsumata, Yasuhiro; Clemens, Paula R.; Ascherman, Dana P.

2010-01-01

Objectives Previous work in humans and in animal models supports a key role for histidyl-tRNA synthetase (HRS=Jo-1) in the pathogenesis of idiopathic inflammatory myopathy. While most investigations have focused on the ability of HRS to trigger adaptive immune responses, in vitro studies clearly indicate that HRS possesses intrinsic chemokine-like properties capable of activating the innate immune system. The purpose of this study was therefore to examine the ability of HRS to direct innate immune responses in a murine model of myositis. Methods Following intramuscular immunization with soluble HRS in the absence of exogenous adjuvant, selected strains of mice were evaluated at different time points for histopathologic evidence of myositis. ELISA-based assessment of autoantibody formation and CFSE proliferation studies provided complementary measures of B and T cell responses triggered by HRS immunization. Results Compared to appropriate control proteins, a murine HRS fusion protein induced robust, statistically significant muscle inflammation in multiple congenic strains of C57BL/6 and NOD mice. Time course experiments revealed that this inflammatory response occurred as early as 7 days post immunization and persisted for up to 7 weeks. Parallel immunization strategies in DO11.10/Rag2−/− and C3H/HeJ (TLR4−/−) mice indicated that the ability of murine HRS to drive muscle inflammation was not dependent on B cell receptor or T cell receptor recognition and did not require TLR4 signaling. Conclusion Collectively, these experiments support a model in which HRS can trigger both innate and adaptive immune responses which culminate in severe muscle inflammation that is the hallmark of idiopathic inflammatory myopathy. PMID:21280002

[Pneumothorax following dry needling treatment: legal and ethical aspects].

PubMed

Ronconi, Gianpaolo; De Giorgio, Fabio; Ricci, Eleonora; Maggi, Loredana; Spagnolo, Antonio G; Ferrara, Paola Emilia

2016-01-01

Trigger point "dry needling" is a technique used to treat myofascial pain. It involves using filiform needles which are inserted into muscles to give local pain relief. Few cases of serious adverse events following this treatment have been reported in the literature. In this paper we describe the case of a professional swimmer who developed pneumothorax after dry needling treatment and discuss the medicolegal and ethical aspects related to competencies and responsibilities of medical doctors and physiotherapists performing the procedure.

Hyperexcitability to electrical stimulation and accelerated muscle fatiguability of taut bands in rats.

PubMed

Wang, Yong-Hui; Yin, Ming-Jing; Fan, Zhen-Zhen; Arendt-Nielsen, Lars; Ge, Hong-You; Yue, Shou-Wei

2014-04-01

Myofascial trigger points contribute significantly to musculoskeletal pain and motor dysfunction and may be associated with accelerated muscle fatiguability. The aim of this study was to investigate the electrically induced force and fatigue characteristics of muscle taut bands in rats. Muscle taut bands were dissected out and subjected to trains of electrical stimulation. The electrical threshold intensity for muscle contraction and maximum contraction force (MCF), electrical intensity dependent fatigue and electrical frequency dependent fatigue characteristics were assessed in three different sessions (n=10 each) and compared with non-taut bands in the biceps femoris muscle. The threshold intensity for muscle contraction and MCF at the 10th, 15th and 20th intensity dependent fatigue stimuli of taut bands were significantly lower than those of non-taut bands (all p<0.05). The MCF at the 15th and 20th intensity dependent fatigue stimuli of taut bands were significantly lower than those at the 1st and 5th stimuli (all p<0.01). The MCF in the frequency dependent fatigue test was significantly higher and the stimulus frequency that induced MCF was significantly lower for taut bands than for non-taut bands (both p<0.01). The present study demonstrates that the muscle taut band itself was more excitable to electrical stimulation and significantly less fatigue resistant than normal muscle fibres.

Prevalence of and referred pain from myofascial trigger points in the forearm muscles in patients with lateral epicondylalgia.

PubMed

Fernández-Carnero, Josué; Fernández-de-Las-Peñas, César; de la Llave-Rincón, Ana Isabel; Ge, Hong-You; Arendt-Nielsen, Lars

2007-05-01

Referred pain and pain characteristics evoked from the extensor carpi radialis brevis, extensor carpi radialis longus, extensor digitorum communis, and brachioradialis muscles was investigated in 20 patients with lateral epicondylalgia (LE) and 20-matched controls. Both groups were examined for the presence of myofascial trigger points (TrPs) in a blinded fashion. The quality and location of the evoked referred pain, and the pressure pain threshold (PPT) at the lateral epicondyle on the right upper extremity (symptomatic side in patients, and dominant-side on controls) were recorded. Several lateral elbow pain parameters were also evaluated. Within the patient group, the elicited referred pain by manual exploration of 13 out of 20 (65%) extensor carpi radialis brevis muscles, 12/20 (70%) extensor carpi radialis longus muscles, 10/20 (50%) brachioradialis muscles, and 5/20 (25%) extensor digitorum communis muscles, shares similar pain patterns as their habitual lateral elbow and forearm pain. The mean number of muscles with TrPs for each patient was 2.9 [95% confidence interval (CI) 1,4] of which 2 (95% CI 1,3) were active, and 0.9 (95% CI 0,2) were latent TrPs. Control participants only had latent TrPs (mean: 0.4; 95% CI 0,2). TrP occurrence between the 2 groups was significantly different for active TrPs (P<0.001), but not for latent TrPs (P>0.05). The referred pain pattern was larger in patients than in controls, with pain referral to the lateral epicondyle (proximally) and to the dorso-lateral aspect of the forearm in the patients, and confined to the dorso-lateral aspect of the forearm in the controls. Patients with LE showed a significant (P<0.001) lower PPT (mean: 2.1 kg/cm; 95% CI 0.8, 4 kg/cm) as compared with controls (mean: 4.5 kg/cm; 95% CI 3, 7 kg/cm). Within the patient group, PPT at the lateral epicondyle was negatively correlated with both the total number of TrPs (rs=-0.63; P=0.003) and the number of active TrPs (rs=-0.5; P=0.02): the greater the number of active TrPs, the lower the PPT at the lateral epicondyle. Our results suggest that in patients with LE, the evoked referred pain and its sensory characteristics shared similar patterns as their habitual elbow and forearm pain, consistent with active TrPs. Lower PPT and larger referred pain patterns suggest that peripheral and central sensitization exists in LE.

Unsupervised clustering of gene expression data points at hypoxia as possible trigger for metabolic syndrome.

PubMed

Ptitsyn, Andrey; Hulver, Matthew; Cefalu, William; York, David; Smith, Steven R

2006-12-19

Classification of large volumes of data produced in a microarray experiment allows for the extraction of important clues as to the nature of a disease. Using multi-dimensional unsupervised FOREL (FORmal ELement) algorithm we have re-analyzed three public datasets of skeletal muscle gene expression in connection with insulin resistance and type 2 diabetes (DM2). Our analysis revealed the major line of variation between expression profiles of normal, insulin resistant, and diabetic skeletal muscle. A cluster of most "metabolically sound" samples occupied one end of this line. The distance along this line coincided with the classic markers of diabetes risk, namely obesity and insulin resistance, but did not follow the accepted clinical diagnosis of DM2 as defined by the presence or absence of hyperglycemia. Genes implicated in this expression pattern are those controlling skeletal muscle fiber type and glycolytic metabolism. Additionally myoglobin and hemoglobin were upregulated and ribosomal genes deregulated in insulin resistant patients. Our findings are concordant with the changes seen in skeletal muscle with altitude hypoxia. This suggests that hypoxia and shift to glycolytic metabolism may also drive insulin resistance.

Genetics Home Reference: paramyotonia congenita

MedlinePlus

... tense (contract) and relax in a coordinated way. Muscle contractions are triggered by the flow of positively charged ... resulting increase in ion flow interferes with normal muscle contraction and relaxation, leading to episodes of muscle stiffness ...

Protocol: Testing the Relevance of Acupuncture Theory in the Treatment of Myofascial Pain in the Upper Trapezius Muscle.

PubMed

Elsdon, Dale S; Spanswick, Selina; Zaslawski, Chris; Meier, Peter C

2017-01-01

A protocol for a prospective single-blind parallel four-arm randomized placebo-controlled trial with repeated measures was designed to test the effects of various acupuncture methods compared with sham. Eighty self-selected participants with myofascial pain in the upper trapezius muscle were randomized into four groups. Group 1 received acupuncture to a myofascial trigger point (MTrP) in the upper trapezius. Group 2 received acupuncture to the MTrP in addition to relevant distal points. Group 3 received acupuncture to the relevant distal points only. Group 4 received a sham treatment to both the MTrP and distal points using a deactivated acupuncture laser device. Treatment was applied four times within 2 weeks with outcomes measured throughout the trial and at 2 weeks and 4 weeks posttreatment. Outcome measurements were a 100-mm visual analog pain scale, SF-36, pressure pain threshold, Neck Disability Index, the Upper Extremity Functional Index, lateral flexion in the neck, McGill Pain Questionnaire, Massachusetts General Hospital Acupuncture Sensation Scale, Working Alliance Inventory (short form), and the Credibility Expectance Questionnaire. Two-way analysis of variance (ANOVA) with repeated measures were used to assess the differences between groups. Copyright © 2017 Medical Association of Pharmacopuncture Institute. Published by Elsevier B.V. All rights reserved.

Short-term changes in neck pain, widespread pressure pain sensitivity, and cervical range of motion after the application of trigger point dry needling in patients with acute mechanical neck pain: a randomized clinical trial.

PubMed

Mejuto-Vázquez, María J; Salom-Moreno, Jaime; Ortega-Santiago, Ricardo; Truyols-Domínguez, Sebastián; Fernández-de-Las-Peñas, César

2014-04-01

Randomized clinical trial. To determine the effects of trigger point dry needling (TrPDN) on neck pain, widespread pressure pain sensitivity, and cervical range of motion in patients with acute mechanical neck pain and active trigger points in the upper trapezius muscle. TrPDN seems to be effective for decreasing pain in individuals with upper-quadrant pain syndromes. Potential effects of TrPDN for decreasing pain and sensitization in individuals with acute mechanical neck pain are needed. Methods Seventeen patients (53% female) were randomly assigned to 1 of 2 groups: a single session of TrPDN or no intervention (waiting list). Pressure pain thresholds over the C5-6 zygapophyseal joint, second metacarpal, and tibialis anterior muscle; neck pain intensity; and cervical spine range-of-motion data were collected at baseline (pretreatment) and 10 minutes and 1 week after the intervention by an assessor blinded to the treatment allocation of the patient. Mixed-model analyses of variance were used to examine the effects of treatment on each outcome variable. Patients treated with 1 session of TrPDN experienced greater decreases in neck pain, greater increases in pressure pain threshold, and higher increases in cervical range of motion than those who did not receive an intervention at both 10 minutes and 1 week after the intervention (P<.01 for all comparisons). Between-group effect sizes were medium to large immediately after the TrPDN session (standardized mean score differences greater than 0.56) and large at the 1-week follow-up (standardized mean score differences greater than 1.34). The results of the current randomized clinical trial suggest that a single session of TrPDN may decrease neck pain intensity and widespread pressure pain sensitivity, and also increase active cervical range of motion, in patients with acute mechanical neck pain. Changes in pain, pressure pain threshold, and cervical range of motion surpassed their respective minimal detectable change values, supporting clinically relevant treatment effects. Level of Evidence Therapy, level 1b-.

Exercise-mimetic AICAR transiently benefits brain function

PubMed Central

Guerrieri, Davide; van Praag, Henriette

2015-01-01

Exercise enhances learning and memory in animals and humans. The role of peripheral factors that may trigger the beneficial effects of running on brain function has been sparsely examined. In particular, it is unknown whether AMP-kinase (AMPK) activation in muscle can predict enhancement of brain plasticity. Here we compare the effects of running and administration of AMPK agonist 5-Aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR, 500 mg/kg), for 3, 7 or 14 days in one-month-old male C57BL/6J mice, on muscle AMPK signaling. At the time-points where we observed equivalent running- and AICAR-induced muscle pAMPK levels (7 and 14 days), cell proliferation, synaptic plasticity and gene expression, as well as markers of oxidative stress and inflammation in the dentate gyrus (DG) of the hippocampus and lateral entorhinal cortex (LEC) were evaluated. At the 7-day time-point, both regimens increased new DG cell number and brain-derived neurotrophic factor (BDNF) protein levels. Furthermore, microarray analysis of DG and LEC tissue showed a remarkable overlap between running and AICAR in the regulation of neuronal, mitochondrial and metabolism related gene classes. Interestingly, while similar outcomes for both treatments were stable over time in muscle, in the brain an inversion occurred at fourteen days. The compound no longer increased DG cell proliferation or neurotrophin levels, and upregulated expression of apoptotic genes and inflammatory cytokine interleukin-1β. Thus, an exercise mimetic that produces changes in muscle consistent with those of exercise does not have the same sustainable positive effects on the brain, indicating that only running consistently benefits brain function. PMID:26286955

Exercise-mimetic AICAR transiently benefits brain function.

PubMed

Guerrieri, Davide; van Praag, Henriette

2015-07-30

Exercise enhances learning and memory in animals and humans. The role of peripheral factors that may trigger the beneficial effects of running on brain function has been sparsely examined. In particular, it is unknown whether AMP-kinase (AMPK) activation in muscle can predict enhancement of brain plasticity. Here we compare the effects of running and administration of AMPK agonist 5-Aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR, 500 mg/kg), for 3, 7 or 14 days in one-month-old male C57BL/6J mice, on muscle AMPK signaling. At the time-points where we observed equivalent running- and AICAR-induced muscle pAMPK levels (7 and 14 days), cell proliferation, synaptic plasticity and gene expression, as well as markers of oxidative stress and inflammation in the dentate gyrus (DG) of the hippocampus and lateral entorhinal cortex (LEC) were evaluated. At the 7-day time-point, both regimens increased new DG cell number and brain-derived neurotrophic factor (BDNF) protein levels. Furthermore, microarray analysis of DG and LEC tissue showed a remarkable overlap between running and AICAR in the regulation of neuronal, mitochondrial and metabolism related gene classes. Interestingly, while similar outcomes for both treatments were stable over time in muscle, in the brain an inversion occurred at fourteen days. The compound no longer increased DG cell proliferation or neurotrophin levels, and upregulated expression of apoptotic genes and inflammatory cytokine interleukin-1β. Thus, an exercise mimetic that produces changes in muscle consistent with those of exercise does not have the same sustainable positive effects on the brain, indicating that only running consistently benefits brain function.

Characteristics of referred muscle pain to the head from active trigger points in women with myofascial temporomandibular pain and fibromyalgia syndrome.

PubMed

Alonso-Blanco, Cristina; Fernández-de-Las-Peñas, César; de-la-Llave-Rincón, Ana Isabel; Zarco-Moreno, Pedro; Galán-Del-Río, Fernando; Svensson, Peter

2012-11-01

Our aim was to compare the differences in the prevalence and the anatomical localization of referred pain areas of active trigger points (TrPs) between women with myofascial temporomandibular disorder (TMD) or fibromyalgia (FMS). Twenty women (age 46 ± 8 years) with TMD and 20 (age 48 ± 6 years) with FMS were recruited from specialized clinic. Bilateral temporalis, masseter, sternocleidomastoid, upper trapezius, and suboccipital muscles were examined for TrPs. TrPs were identified by palpation and considered active when the pain reproduced familiar pain symptom experienced by the patient. The referred pain areas were drawn on anatomical maps, digitalized and also measured. A new analysis technique based on a center of gravity (COG) method was used to quantitative estimate of the localization of the TrP referred pain areas. Women with FMS exhibited larger areas of usual pain symptoms than women with myofascial TMD (P < 0.001). The COG coordinates of the usual pain on the frontal and posterior pain maps were located more superior in TMD than in FMS. The number of active TrPs was significantly higher in TMD (mean ± SD 6 ± 1) than in FMS (4 ± 1) (P = 0.002). Women with TMD exhibited more active TrPs in the temporalis and masseter muscles than FMS (P < 0.01). Women with FMS had larger referred pain areas than those with TMD for sternocleidomastoid and suboccipital muscles (P < 0.001). Significant differences within COG coordinates of TrP referred pain areas were found in TMD, the referred pain was more pronounced in the orofacial region, whereas the referred pain in FMS was more pronounced in the cervical spine. This study showed that the referred pain elicited from active TrPs shared similar patterns as usual pain symptoms in women with TMD or FMS, but that distinct differences in TrP prevalence and location of the referred pain areas could be observed. Differences in location of referred pain areas may help clinicians to determine the most relevant TrPs for each pain syndrome in spite of overlaps in pain areas.

Induction of Sirt1 by Mechanical Stretch of Skeletal Muscle through the Early Response Factor EGR1 Triggers an Antioxidative Response*

PubMed Central

Pardo, Patricia S.; Mohamed, Junaith S.; Lopez, Michael A.; Boriek, Aladin M.

2011-01-01

Mechanical loading of muscles by intrinsic muscle activity or passive stretch leads to an increase in the production of reactive oxygen species (1, 2). The NAD-dependent protein deacetylase SIRT1 is involved in the protection against oxidative stress by enhancing FOXO-driven Sod2 transcription (3–5). In this report, we unravel a mechanism triggered by mechanical stretch of skeletal muscle cells that leads to an EGR1-dependent transcriptional activation of the Sirt1 gene. The resulting transient increase in SIRT1 expression generates an antioxidative response that contributes to reactive oxygen species scavenging. PMID:20971845

Effect of neuromuscular electrical stimulation on motor cortex excitability upon release of tonic muscle contraction.

PubMed

Sugawara, Kenichi; Tanabe, Shigeo; Suzuki, Tomotaka; Higashi, Toshio

The aim of the present study was to investigate the neurophysiological triggers underlying muscle relaxation from the contracted state, and to examine the mechanisms involved in this process and their subsequent modification by neuromuscular electrical stimulation (NMES). Single-pulse transcranial magnetic stimulation (TMS) was used to produce motor-evoked potentials (MEPs) and short-interval intracortical inhibition (SICI) in 23 healthy participants, wherein motor cortex excitability was examined at the onset of voluntary muscle relaxation following a period of voluntary tonic muscle contraction. In addition, the effects of afferent input on motor cortex excitability, as produced by NMES during muscle contraction, were examined. In particular, two NMES intensities were used for analysis: 1.2 times the sensory threshold and 1.2 times the motor threshold (MT). Participants were directed to execute constant wrist extensions and to release muscle contraction in response to an auditory "GO" signal. MEPs were recorded from the flexor carpi radialis (FCR) and extensor carpi radialis (ECR) muscles, and TMS was applied at three different time intervals (30, 60, and 90 ms) after the "GO" signal. Motor cortex excitability was greater during voluntary ECR and FCR relaxation using high-intensity NMES, and relaxation time was decreased. Each parameter differed significantly between 30 and 60 ms. Moreover, in both muscles, SICI was larger in the presence than in the absence of NMES. Therefore, the present findings suggest that terminating a muscle contraction triggers transient neurophysiological mechanisms that facilitate the NMES-induced modulation of cortical motor excitability in the period prior to muscle relaxation. High-intensity NMES might facilitate motor cortical excitability as a function of increased inhibitory intracortical activity, and therefore serve as a transient trigger for the relaxation of prime mover muscles in a therapeutic context.

Referred pain elicited by manual exploration of the lateral rectus muscle in chronic tension-type headache.

PubMed

Fernández-de-Las-Peñas, César; Cuadrado, Maria Luz; Gerwin, Robert D; Pareja, Juan A

2009-01-01

To analyze the presence of referred pain elicited by manual examination of the lateral rectus muscle in patients with chronic tension-type headache (CTTH). A case-control blinded study. It has been found previously that the manual examination of the superior oblique muscle can elicit referred pain to the head in some patients with migraine or tension-type headache. However, a referred pain from other extraocular muscles has not been investigated. Fifteen patients with CTTH and 15 healthy subjects without headache history were included. A blinded assessor performed a manual examination focused on the search for myofascial trigger points (TrPs) in the right and left lateral rectus muscles. TrP diagnosis was made when there was referred pain evoked by maintained pressure on the lateral corner of the orbit (anatomical projection of the lateral rectus muscle) for 20 seconds, and increased referred pain while the subject maintained a medial gaze on the corresponding side (active stretching of the muscle) for 15 seconds. On each side, a 10-point numerical pain rate scale was used to assess the intensity of referred pain at both stages of the examination. Ten patients with CTTH (66.6%) had referred pain that satisfied TrPs diagnostic criteria, while only one healthy control (0.07%) reported referred pain upon the examination of the lateral rectus muscles (P < 0.001). The elicited referred pain was perceived as a deep ache located at the supraorbital region or the homolateral forehead. Pain was evoked on both sides in all subjects with TrPs, with no difference in pain intensity between the right and the left. The average pain intensity was significantly greater in the patient group (P < 0.001). All CTTH patients with referred pain recognized it as the frontal pain that they usually experienced during their headache attacks, which was consistent with active TrPs. In some patients with CTTH, the manual examination of lateral rectus muscle TrPs elicits a referred pain that extends to the supraorbital region or the homolateral forehead. Nociceptive inputs from the extraocular muscles may sustain the activation of trigeminal neuron, thus sensitizing central pain pathways and exacerbating headache.

Contribution of myofascial trigger points to migraine symptoms.

PubMed

Giamberardino, Maria Adele; Tafuri, Emmanuele; Savini, Antonella; Fabrizio, Alessandra; Affaitati, Giannapia; Lerza, Rosanna; Di Ianni, Livio; Lapenna, Domenico; Mezzetti, Andrea

2007-11-01

This study evaluated the contribution of myofascial trigger points (TrPs) to migraine pain. Seventy-eight migraine patients with cervical active TrPs whose referred areas (RAs) coincided with migraine sites (frontal/temporal) underwent electrical pain threshold measurement in skin, subcutis, and muscle in TrPs and RAs at baseline and after 3, 10, 30, and 60 days; migraine pain assessment (number and intensity of attacks) for 60 days before and 60 days after study start. Fifty-four patients (group 1) underwent TrP anesthetic infiltration on the 3rd, 10th, 30th, and 60th day (after threshold measurement); 24 (group 2) received no treatment. Twenty normal subjects underwent threshold measurements in the same sites and time points as patients. At baseline, all patients showed lower than normal thresholds in TrPs and RAs in all tissues (P < .001). During treatment in group 1, all thresholds increased progressively in TrPs and RAs (P < .0001), with sensory normalization of skin/subcutis in RAs at the end of treatment; migraine pain decreased (P < .001). Threshold increase in RAs and migraine reduction correlated linearly (.0001 < P < .006). In group 2 and normal subjects, no changes occurred. Cervical TrPs with referred areas in migraine sites thus contribute substantially to migraine symptoms, the peripheral nociceptive input from TrPs probably enhancing the sensitization level of central sensory neurons. This article shows the beneficial effects of local therapy of active myofascial trigger points (TrPs) on migraine symptoms in patients in whom migraine sites coincide with the referred areas of the TrPs. These results suggest that migraine pain is often contributed to by myofascial inputs that enhance the level of central neuronal excitability.

Low-level laser therapy (LLLT) accelerates the sternomastoid muscle regeneration process after myonecrosis due to bupivacaine.

PubMed

Alessi Pissulin, Cristiane Neves; Henrique Fernandes, Ana Angélica; Sanchez Orellana, Alejandro Manuel; Rossi E Silva, Renata Calciolari; Michelin Matheus, Selma Maria

2017-03-01

Because of its long-lasting analgesic action, bupivacaine is an anesthetic used for peripheral nerve block and relief of postoperative pain. Muscle degeneration and neurotoxicity are its main limitations. There is strong evidence that low-level laser therapy (LLLT) assists in muscle and nerve repair. The authors evaluated the effects of a Gallium Arsenide laser (GaAs), on the regeneration of muscle fibers of the sternomastoid muscle and accessory nerve after injection of bupivacaine. In total, 30 Wistar adult rats were divided into 2 groups: control group (C: n=15) and laser group (L: n=15). The groups were subdivided by antimere, with 0.5% bupivacaine injected on the right and 0.9% sodium chloride on the left. LLLT (GaAs 904nm, 0,05W, 2.8J per point) was administered for 5 consecutive days, starting 24h after injection of the solutions. Seven days after the trial period, blood samples were collected for determination of creatine kinase (CK). The sternomastoid nerve was removed for morphological and morphometric analyses; the surface portion of the sternomastoid muscle was used for histopathological and ultrastructural analyses. Muscle CK and TNFα protein levels were measured. The anesthetic promoted myonecrosis and increased muscle CK without neurotoxic effects. The LLLT reduced myonecrosis, characterized by a decrease in muscle CK levels, inflammation, necrosis, and atrophy, as well as the number of central nuclei in the muscle fibers and the percentage of collagen. TNFα values remained constant. LLLT, at the dose used, reduced fibrosis and myonecrosis in the sternomastoid muscle triggered by bupivacaine, accelerating the muscle regeneration process. Copyright © 2017 Elsevier B.V. All rights reserved.

Clinical Assessment and Diagnostics of Patients With Hand Disorders: A Case Study Approach.

PubMed

Leow, Mabel Qi He; Lim, Rebecca Qian Ru; Tay, Shian Chao

Clinical assessment of the hand is important for diagnosing underlying hand disorders. Using a case study approach, the clinical assessment for three disorders of the hands is presented: trigger finger (stenosing tenosynovitis), carpal tunnel syndrome, and ulnar-sided wrist injury (styloid impingement). We assess the annular one pulley and finger range of motion for patients with trigger finger. To diagnose for carpal tunnel syndrome, assessment for Tinel's sign, Phalen's sign, abductor pollicis brevis muscle bulk, two-point discrimination, and obtaining a nerve conduction study are performed. Assessment for ulnar-sided wrist injury includes wrist range of motion, assessment of distal radial ulnar joint stability, provocation tests, grip strength, x-ray, and magnetic resonance imaging. This article begins with a description of the hand and wrist anatomy. For each case study, the clinical history is described, followed by a discussion of the pathophysiology, clinical assessments, and diagnostic tests.

Botulinum toxin (BoNT) and back pain.

PubMed

Porta, Mauro; Maggioni, G

2004-02-01

Myofascial pain syndrome is defined as subacute or chronic pain with sensory, motor and autonomic symptoms referred from active trigger points with associated painful dysfunctions. Authors present the usefulness of botulinum toxin A or B (BoNT/A or BoNT/B) injected into target muscles since the toxin is capable of controlling not only the muscular spasm but mostly the pain by alternative mechanisms of action, which are discussed. Posology of BoNT, technical aspects and results are presented. BoNT represents an interesting and useful tool for an adequate management of patients with myofascial pain.

[Multimodal therapeutic approach of vaginismus: an innovative approach through trigger point infiltration and pulsed radiofrequency of the pudendal nerve].

PubMed

Carvalho, Joana Chaves Gonçalves Rodrigues de; Agualusa, Luís Miguel; Moreira, Luísa Manuela Ribeiro; Costa, Joana Catarina Monteiro da

Vaginismus is a poorly understood disorder, characterized by an involuntary muscular spasm of the pelvic floor muscles and outer third of the vagina during intercourse attempt, which results in aversion to penetration. It is reported to affect 1-7% of women worldwide. With this report the authors aim to describe the case of a young patient with vaginismus in whom techniques usually from the chronic pain domain were used as part of her multimodal therapeutic regimen. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Muscle Expression of SOD1G93A Triggers the Dismantlement of Neuromuscular Junction via PKC-Theta.

PubMed

Dobrowolny, Gabriella; Martini, Martina; Scicchitano, Bianca Maria; Romanello, Vanina; Boncompagni, Simona; Nicoletti, Carmine; Pietrangelo, Laura; De Panfilis, Simone; Catizone, Angela; Bouchè, Marina; Sandri, Marco; Rudolf, Rüdiger; Protasi, Feliciano; Musarò, Antonio

2018-04-20

Neuromuscular junction (NMJ) represents the morphofunctional interface between muscle and nerve. Several chronic pathologies such as aging and neurodegenerative diseases, including muscular dystrophy and amyotrophic lateral sclerosis, display altered NMJ and functional denervation. However, the triggers and the molecular mechanisms underlying the dismantlement of NMJ remain unclear. Here we provide evidence that perturbation in redox signaling cascades, induced by muscle-specific accumulation of mutant SOD1 G93A in transgenic MLC/SOD1 G93A mice, is causally linked to morphological alterations of the neuromuscular presynaptic terminals, high turnover rate of acetylcholine receptor, and NMJ dismantlement. The analysis of potential molecular mechanisms that mediate the toxic activity of SOD1 G93A revealed a causal link between protein kinase Cθ (PKCθ) activation and NMJ disintegration. The study discloses the molecular mechanism that triggers functional denervation associated with the toxic activity of muscle SOD1 G93A expression and suggests the possibility of developing a new strategy to counteract age- and pathology-associated denervation based on pharmacological inhibition of PKCθ activity. Collectively, these data indicate that muscle-specific accumulation of oxidative damage can affect neuromuscular communication and induce NMJ dismantlement through a PKCθ-dependent mechanism. Antioxid. Redox Signal. 28, 1105-1119.

Cortical Effects on Ipsilateral Hindlimb Muscles Revealed with Stimulus-Triggered Averaging of EMG Activity

PubMed Central

Messamore, William G.; Van Acker, Gustaf M.; Hudson, Heather M.; Zhang, Hongyu Y.; Kovac, Anthony; Nazzaro, Jules; Cheney, Paul D.

2016-01-01

While a large body of evidence supports the view that ipsilateral motor cortex may make an important contribution to normal movements and to recovery of function following cortical injury (Chollet et al. 1991; Fisher 1992; Caramia et al. 2000; Feydy et al. 2002), relatively little is known about the properties of output from motor cortex to ipsilateral muscles. Our aim in this study was to characterize the organization of output effects on hindlimb muscles from ipsilateral motor cortex using stimulus-triggered averaging of EMG activity. Stimulus-triggered averages of EMG activity were computed from microstimuli applied at 60–120 μA to sites in both contralateral and ipsilateral M1 of macaque monkeys during the performance of a hindlimb push–pull task. Although the poststimulus effects (PStEs) from ipsilateral M1 were fewer in number and substantially weaker, clear and consistent effects were obtained at an intensity of 120 μA. The mean onset latency of ipsilateral poststimulus facilitation was longer than contralateral effects by an average of 0.7 ms. However, the shortest latency effects in ipsilateral muscles were as short as the shortest latency effects in the corresponding contralateral muscles suggesting a minimal synaptic linkage that is equally direct in both cases. PMID:26088970

Dry needling for the management of thoracic spine pain

PubMed Central

Fernández-de-las-Peñas, César; Layton, Michelle; Dommerholt, Jan

2015-01-01

Thoracic spine pain is as disabling as neck and low back pain without receiving the same level of attention in the scientific literature. Among the different structures that can refer pain to the thoracic spine, muscles often play a relevant role. Trigger points (TrPs) from neck, shoulder and spinal muscles can induce pain in the region of the thoracic spine. There is a lack of evidence reporting the presence of TrPs in the region of the thoracic spine, but clinical evidence suggests that TrPs can be a potential source of thoracic spine pain. The current paper discusses the role of TrPs in the thoracic spine and dry needling (DN) for the management of TrPs in the thoracic multifidi and longissimus thoracis. This paper also includes a brief discussion of the application of DN in other tissues such as tendons, ligaments and scars. PMID:26309385

Carpal tunnel syndrome - an occupational hazard facing dentistry.

PubMed

Abichandani, Sagar; Shaikh, Saquib; Nadiger, Ramesh

2013-10-01

The authors wished to evaluate the comprehensive literature on carpal tunnel syndrome to discover work specific to carpal tunnel syndrome among dentists in order to determine whether there is any correlation with dentists having a higher prevalence of its occurrence. A review of dental literature involving carpal tunnel syndrome was undertaken. Details appearing in the literature before 1995 was reviewed in a comprehensive manner and the literature after 1995 were reviewed electronically. The prevalence of carpal tunnel syndrome is higher in dental professionals involved in various aspects of dental specialties. Abnormal postures, including muscle imbalances, muscle necrosis, trigger points, hypomobile joints, nerve compression and spinal disk herniation or degeneration may result in serious detrimental physiological changes in the body. These changes often result in pain, injury or possible neuroskeletal disorders. Dentists have an increased risk of carpal tunnel syndrome and precautions and care should be exercised to prevent detrimental irreversible changes occurring. © 2013 FDI World Dental Federation.

Postsynaptic ERG potassium channels limit muscle excitability to allow distinct egg-laying behavior states in C. elegans

PubMed Central

Collins, Kevin M.; Koelle, Michael R.

2013-01-01

C. elegans regulates egg laying by alternating between an inactive phase and a serotonin-triggered active phase. We found that the conserved ERG potassium channel UNC-103 enables this two-state behavior by limiting excitability of the egg-laying muscles. Using both high-speed video recording and calcium imaging of egg-laying muscles in behaving animals, we found that the muscles appear to be excited at a particular phase of each locomotor body bend. During the inactive phase, this rhythmic excitation infrequently evokes calcium transients or contraction of the egg-laying muscles. During the serotonin-triggered active phase, however, these muscles are more excitable and each body bend is accompanied by a calcium transient that drives twitching or full contraction of the egg-laying muscles. We found that ERG null mutants lay eggs too frequently, and that ERG function is necessary and sufficient in the egg-laying muscles to limit egg laying. ERG K+ channels localize to postsynaptic sites in the egg-laying muscle, and mutants lacking ERG have more frequent calcium transients and contractions of the egg-laying muscles even during the inactive phase. Thus ERG channels set postsynaptic excitability at a threshold so that further adjustments of excitability by serotonin generate two distinct behavioral states. PMID:23303953

The mechanisms of cachexia underlying muscle dysfunction in COPD.

PubMed

Remels, A H V; Gosker, H R; Langen, R C J; Schols, A M W J

2013-05-01

Pulmonary cachexia is a prevalent, debilitating, and well-recognized feature of COPD associated with increased mortality and loss of peripheral and respiratory muscle function. The exact cause and underlying mechanisms of cachexia in COPD are still poorly understood. Increasing evidence, however, shows that pathological changes in intracellular mechanisms of muscle mass maintenance (i.e., protein turnover and myonuclear turnover) are likely involved. Potential factors triggering alterations in these mechanisms in COPD include oxidative stress, myostatin, and inflammation. In addition to muscle wasting, peripheral muscle in COPD is characterized by a fiber-type shift toward a more type II, glycolytic phenotype and an impaired oxidative capacity (collectively referred to as an impaired oxidative phenotype). Atrophied diaphragm muscle in COPD, however, displays an enhanced oxidative phenotype. Interestingly, intrinsic abnormalities in (lower limb) peripheral muscle seem more pronounced in either cachectic patients or weight loss-susceptible emphysema patients, suggesting that muscle wasting and intrinsic changes in peripheral muscle's oxidative phenotype are somehow intertwined. In this manuscript, we will review alterations in mechanisms of muscle mass maintenance in COPD and discuss the involvement of oxidative stress, inflammation, and myostatin as potential triggers of cachexia. Moreover, we postulate that an impaired muscle oxidative phenotype in COPD can accelerate the process of cachexia, as it renders muscle in COPD less energy efficient, thereby contributing to an energy deficit and weight loss when not dietary compensated. Furthermore, loss of peripheral muscle oxidative phenotype may increase the muscle's susceptibility to inflammation- and oxidative stress-induced muscle damage and wasting.

Chronic abdominal wall pain--a diagnostic challenge for the surgeon.

PubMed

Lindsetmo, Rolv-Ole; Stulberg, Jonah

2009-07-01

Chronic abdominal wall pain (CAWP) occurs in about 30% of all patients presenting with chronic abdominal pain. The authors review the literature identified in a PubMed search regarding the abdominal wall as the origin of chronic abdominal pain. CAWP is frequently misinterpreted as visceral or functional abdominal pain. Misdiagnosis often leads to a variety of investigational procedures and even abdominal operations with negative results. With a simple clinical test (Carnett's test), >90% of patients with CAWP can be recognized, without risk for missing intra-abdominal pathology. The condition can be confirmed when the injection of local anesthetics in the trigger point(s) relieves the pain. A fasciotomy in the anterior abdominal rectus muscle sheath through the nerve foramina of the affected branch of one of the anterior intercostal nerves heals the pain.

THE USE OF TRIGGER POINT DRY NEEDLING AND INTRAMUSCULAR ELECTRICAL STIMULATION FOR A SUBJECT WITH CHRONIC LOW BACK PAIN: A CASE REPORT

PubMed Central

2013-01-01

Study Design: Case Report. Background and Purpose: Myofascial trigger points (MTrPs) are widely accepted by clinicians and researchers as a primary source of regional neuromusculoskeletal pain. Trigger point dry needling (TrP‐DN) is an invasive procedure that involves stimulation of MTrPs using an monofilament needle. The purpose of this case report is to report the outcomes of TrP‐DN and intramuscular electrical stimulation (IES) as a primary treatment intervention in a subject with chronic low back pain. Case Description: The subject was a 30‐year‐old female, active duty military, who was referred to physical therapy for low back and right posterolateral hip pain. She noticed symptoms after suffering a lumbar flexion injury while picking up a barbell during weight training. Physical examination demonstrated findings that supported the diagnosis of lumbar segmental instability with a right hip stability dysfunction. Objective findings included a multi‐segmental flexion movement pattern dysfunction and MTrPs in the right gluteus maximus and gluteus medius muscles with deep palpation. The subject was treated with TrP‐DN and IES for a total of two visits. Bilateral L3 and L5 multifidus and right gluteus maximus and medius muscles were treated, along with implementing a home exercise program consisting of core stability exercises. Outcomes: The subject reported no existing pain and disability on the Numerical Pain Rating Scale and Oswestry Disability Questionnaire and a large perceived change in recovery on the Global Rating of Change at final follow‐up. Physical examination was normal, demonstrating no observed impairments or functional limitations, including normal multi‐segmental flexion and no MTrPs with deep palpation. Discussion: The subject was able to return to full military active duty without any physical limitations and resumed pre‐injury activity levels, including the ability to resume all activities without pain. There is much promise regarding the use of TrP‐DN with IES intervention for the treatment of lumbar and/or hip stability dysfunction. Future research is recommended to determine if TrP‐DN intervention, with and without IES, is effective for other body regions and long‐term subject outcomes. Level of Evidence: Level 4. PMID:23593553

Effect of Dry Needling on Thigh Muscle Strength and Hip Flexion in Elite Soccer Players.

PubMed

Haser, Christian; Stöggl, Thomas; Kriner, Monika; Mikoleit, Jörg; Wolfahrt, Bernd; Scherr, Johannes; Halle, Martin; Pfab, Florian

2017-02-01

Increase in muscle force, endurance, and flexibility is desired in elite athletes to improve performance and to avoid injuries, but it is often hindered by the occurrence of myofascial trigger points. Dry needling (DN) has been shown effective in eliminating myofascial trigger points. This randomized controlled study in 30 elite youth soccer players of a professional soccer Bundesliga Club investigated the effects of four weekly sessions of DN plus water pressure massage on thigh muscle force and range of motion of hip flexion. A group receiving placebo laser plus water pressure massage and a group with no intervention served as controls. Data were collected at baseline (M1), treatment end (M2), and 4 wk follow-up (M3). Furthermore, a 5-month muscle injury follow-up was performed. DN showed significant improvement of muscular endurance of knee extensors at M2 (P = 0.039) and M3 (P = 0.008) compared with M1 (M1:294.6 ± 15.4 N·m·s, M2:311 ± 25 N·m·s; M3:316.0 ± 28.6 N·m·s) and knee flexors at M2 compared with M1 (M1:163.5 ± 10.9 N·m·s, M2:188.5 ± 16.3 N·m·s) as well as hip flexion (M1: 81.5° ± 3.3°, M2:89.8° ± 2.8°; M3:91.8° ± 3.8°). Compared with placebo (3.8° ± 3.8°) and control (1.4° ± 2.9°), DN (10.3° ± 3.5°) showed a significant (P = 0.01 and P = 0.0002) effect at M3 compared with M1 on hip flexion; compared with nontreatment control (-10 ± 11.9 N·m), DN (5.2 ± 10.2 N·m) also significantly (P = 0.049) improved maximum force of knee extensors at M3 compared with M1. During the rest of the season, muscle injuries were less frequent in the DN group compared with the control group. DN showed a significant effect on muscular endurance and hip flexion range of motion that persisted 4 wk posttreatment. Compared with placebo, it showed a significant effect on hip flexion that persisted 4 wk posttreatment, and compared with nonintervention control, it showed a significant effect on maximum force of knee extensors 4 wk posttreatment in elite soccer players.

Mechanisms of Myofascial Pain

PubMed Central

Jafri, M. Saleet

2014-01-01

Myofascial pain syndrome is an important health problem. It affects a majority of the general population, impairs mobility, causes pain, and reduces the overall sense of well-being. Underlying this syndrome is the existence of painful taut bands of muscle that contain discrete, hypersensitive foci called myofascial trigger points. In spite of the significant impact on public health, a clear mechanistic understanding of the disorder does not exist. This is likely due to the complex nature of the disorder which involves the integration of cellular signaling, excitation-contraction coupling, neuromuscular inputs, local circulation, and energy metabolism. The difficulties are further exacerbated by the lack of an animal model for myofascial pain to test mechanistic hypothesis. In this review, current theories for myofascial pain are presented and their relative strengths and weaknesses are discussed. Based on new findings linking mechanoactivation of reactive oxygen species signaling to destabilized calcium signaling, we put forth a novel mechanistic hypothesis for the initiation and maintenance of myofascial trigger points. It is hoped that this lays a new foundation for understanding myofascial pain syndrome and how current therapies work, and gives key insights that will lead to the improvement of therapies for its treatment. PMID:25574501

Muscle-specific and age-related changes in protein synthesis and protein degradation in response to hindlimb unloading in rats

PubMed Central

Baehr, Leslie M.; West, Daniel W. D.; Marshall, Andrea G.; Marcotte, George R.; Baar, Keith

2017-01-01

Disuse is a potent inducer of muscle atrophy, but the molecular mechanisms driving this loss of muscle mass are highly debated. In particular, the extent to which disuse triggers decreases in protein synthesis or increases in protein degradation, and whether these changes are uniform across muscles or influenced by age, is unclear. We aimed to determine the impact of disuse on protein synthesis and protein degradation in lower limb muscles of varied function and fiber type in adult and old rats. Alterations in protein synthesis and degradation were measured in the soleus, medial gastrocnemius, and tibialis anterior (TA) muscles of adult and old rats subjected to hindlimb unloading (HU) for 3, 7, or 14 days. Loss of muscle mass was progressive during the unloading period, but highly variable (−9 to −38%) across muscle types and between ages. Protein synthesis decreased significantly in all muscles, except for the old TA. Atrophy-associated gene expression was only loosely associated with protein degradation as muscle RING finger-1, muscle atrophy F-box (MAFbx), and Forkhead box O1 expression significantly increased in all muscles, but an increase in proteasome activity was only observed in the adult soleus. MAFbx protein levels were significantly higher in the old muscles compared with adult muscles, despite the old having higher expression of microRNA-23a. These results indicate that adult and old muscles respond similarly to HU, and the greatest loss in muscle mass occurs in predominantly slow-twitch extensor muscles due to a concomitant decrease in protein synthesis and increase in protein degradation. NEW & NOTEWORTHY In this study, we showed that age did not intensify the atrophy response to unloading in rats, but rather that the degree of atrophy was highly variable across muscles, indicating that changes in protein synthesis and protein degradation occur in a muscle-specific manner. Our data emphasize the importance of studying muscles of varying fiber-type and physiological function at multiple time points to fully understand the molecular mechanisms responsible for disuse atrophy. PMID:28336537

Novel excitation-contraction coupling related genes reveal aspects of muscle weakness beyond atrophy—new hopes for treatment of musculoskeletal diseases

PubMed Central

Manring, Heather; Abreu, Eduardo; Brotto, Leticia; Weisleder, Noah; Brotto, Marco

2013-01-01

Research over the last decade strengthened the understanding that skeletal muscles are not only the major tissue in the body from a volume point of view but also function as a master regulator contributing to optimal organismal health. These new contributions to the available body of knowledge triggered great interest in the roles of skeletal muscle beyond contraction. The World Health Organization, through its Global Burden of Disease (GBD) report, recently raised further awareness about the key importance of skeletal muscles as the GDB reported musculoskeletal (MSK) diseases have become the second greatest cause of disability, with more than 1.7 billion people in the globe affected by a diversity of MSK conditions. Besides their role in MSK disorders, skeletal muscles are also seen as principal metabolic organs with essential contributions to metabolic disorders, especially those linked to physical inactivity. In this review, we have focused on the unique function of new genes/proteins (i.e., MTMR14, MG29, sarcalumenin, KLF15) that during the last few years have helped provide novel insights about muscle function in health and disease, muscle fatigue, muscle metabolism, and muscle aging. Next, we provide an in depth discussion of how these genes/proteins converge into a common function of acting as regulators of intracellular calcium homeostasis. A clear link between dysfunctional calcium homeostasis is established and the special role of store-operated calcium entry is analyzed. The new knowledge that has been generated by the understanding of the roles of previously unknown modulatory genes of the skeletal muscle excitation-contraction coupling (ECC) process brings exciting new possibilities for treatment of MSK diseases, muscle regeneration, and skeletal muscle tissue engineering. The next decade of skeletal muscle and MSK research is bound to bring to fruition applied knowledge that will hopefully offset the current heavy and sad burden of MSK diseases on the planet. PMID:24600395

Novel excitation-contraction coupling related genes reveal aspects of muscle weakness beyond atrophy-new hopes for treatment of musculoskeletal diseases.

PubMed

Manring, Heather; Abreu, Eduardo; Brotto, Leticia; Weisleder, Noah; Brotto, Marco

2014-01-01

Research over the last decade strengthened the understanding that skeletal muscles are not only the major tissue in the body from a volume point of view but also function as a master regulator contributing to optimal organismal health. These new contributions to the available body of knowledge triggered great interest in the roles of skeletal muscle beyond contraction. The World Health Organization, through its Global Burden of Disease (GBD) report, recently raised further awareness about the key importance of skeletal muscles as the GDB reported musculoskeletal (MSK) diseases have become the second greatest cause of disability, with more than 1.7 billion people in the globe affected by a diversity of MSK conditions. Besides their role in MSK disorders, skeletal muscles are also seen as principal metabolic organs with essential contributions to metabolic disorders, especially those linked to physical inactivity. In this review, we have focused on the unique function of new genes/proteins (i.e., MTMR14, MG29, sarcalumenin, KLF15) that during the last few years have helped provide novel insights about muscle function in health and disease, muscle fatigue, muscle metabolism, and muscle aging. Next, we provide an in depth discussion of how these genes/proteins converge into a common function of acting as regulators of intracellular calcium homeostasis. A clear link between dysfunctional calcium homeostasis is established and the special role of store-operated calcium entry is analyzed. The new knowledge that has been generated by the understanding of the roles of previously unknown modulatory genes of the skeletal muscle excitation-contraction coupling (ECC) process brings exciting new possibilities for treatment of MSK diseases, muscle regeneration, and skeletal muscle tissue engineering. The next decade of skeletal muscle and MSK research is bound to bring to fruition applied knowledge that will hopefully offset the current heavy and sad burden of MSK diseases on the planet.

Blunted Myoglobin and Quadriceps Soreness after Electrical Stimulation during the Luteal Phase or Oral Contraception

ERIC Educational Resources Information Center

Anderson, Lindsey J.; Baker, Lucinda L.; Schroeder, E. Todd

2017-01-01

Purpose: Acute muscle damage after exercise triggers subsequent regeneration, leading to hypertrophy and increased strength after repeated exercise. It has been debated whether acute exercise-induced muscle damage is altered under various premenopausal estrogen conditions. Acute contraction-induced muscle damage was compared during exogenous (oral…

Comparison of shoulder strength in males with and without myofascial trigger points in the upper trapezius.

PubMed

Kim, H A; Hwang, U J; Jung, S H; Ahn, S H; Kim, J H; Kwon, O Y

2017-11-01

This study was conducted in order to compare the strength of scapular elevator and shoulder abductor with and without restricted scapular elevation between male subjects with and without myofascial trigger points in the upper trapezius. In total, 15 male subjects with myofascial trigger points, and 15age- and weight-matched male subjects without myofascial trigger points in the upper trapezius. Each subject was measured in the strength of maximum isometric scapular elevation and shoulder abduction with and without restricted scapular elevation. Maximum isometric contractions were measured using the Smart KEMA strength measurement system. Independent t-tests were used to compare shoulder strength values between the myofascial trigger points and non- myofascial trigger points groups. The results showed that shoulder abductor strength in the group with myofascial trigger points (5.64kgf) was significantly lower than in the group without myofascial trigger points (11.96kgf) when scapular elevation was restricted (p<0.05). However, there was no significant difference in the strength of the scapular elevator or shoulder abductor between groups (p>0.05). These findings suggest that decreased strength in the shoulder abductor with restricted scapular elevation should be considered in evaluating and treating individuals with myofascial trigger points of the upper trapezius. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mechanisms underlying ICU muscle wasting and effects of passive mechanical loading

PubMed Central

2012-01-01

Introduction Critically ill ICU patients commonly develop severe muscle wasting and impaired muscle function, leading to delayed recovery, with subsequent increased morbidity and financial costs, and decreased quality of life for survivors. Critical illness myopathy (CIM) is a frequently observed neuromuscular disorder in ICU patients. Sepsis, systemic corticosteroid hormone treatment and post-synaptic neuromuscular blockade have been forwarded as the dominating triggering factors. Recent experimental results from our group using a unique experimental rat ICU model show that the mechanical silencing associated with CIM is the primary triggering factor. This study aims to unravel the mechanisms underlying CIM, and to evaluate the effects of a specific intervention aiming at reducing mechanical silencing in sedated and mechanically ventilated ICU patients. Methods Muscle gene/protein expression, post-translational modifications (PTMs), muscle membrane excitability, muscle mass measurements, and contractile properties at the single muscle fiber level were explored in seven deeply sedated and mechanically ventilated ICU patients (not exposed to systemic corticosteroid hormone treatment, post-synaptic neuromuscular blockade or sepsis) subjected to unilateral passive mechanical loading for 10 hours per day (2.5 hours, four times) for 9 ± 1 days. Results These patients developed a phenotype considered pathognomonic of CIM; that is, severe muscle wasting and a preferential myosin loss (P < 0.001). In addition, myosin PTMs specific to the ICU condition were observed in parallel with an increased sarcolemmal expression and cytoplasmic translocation of neuronal nitric oxide synthase. Passive mechanical loading for 9 ± 1 days resulted in a 35% higher specific force (P < 0.001) compared with the unloaded leg, although it was not sufficient to prevent the loss of muscle mass. Conclusion Mechanical silencing is suggested to be a primary mechanism underlying CIM; that is, triggering the myosin loss, muscle wasting and myosin PTMs. The higher neuronal nitric oxide synthase expression found in the ICU patients and its cytoplasmic translocation are forwarded as a probable mechanism underlying these modifications. The positive effect of passive loading on muscle fiber function strongly supports the importance of early physical therapy and mobilization in deeply sedated and mechanically ventilated ICU patients. PMID:23098317

Cardiovascular safety of antihistamines

PubMed Central

Olasiński, Jerzy; Grajek, Stefan

2014-01-01

Histamine is a mediator, which increases the permeability of capillaries during the early phase of allergic reaction, causes smooth muscle contraction of bronchi and stimulates mucous glands in the nasal cavity. Antihistamines are the basis of symptomatic treatment in the majority of allergic diseases, especially allergic rhinitis, allergic conjunctivitis, urticaria and anaphylaxis. The cardiotoxic effects of the two withdrawn drugs, terfenadine and astemizole, were manifested by prolonged QT intervals and triggering torsades de pointes (TdP) caused by blockade of the ‘rapid’ IKr potassium channels. These phenomena, however, are not a class effect. This review deals with a new generation of antihistamine drugs in the context of QT interval prolongation risk. PMID:25097491

Leptin signaling protects the gut from Entamoeba histolytica infection.

PubMed

Vedantam, Gayatri; Viswanathan, V K

2012-01-01

The role of the adipose-derived hormone leptin, and leptin receptors, in signaling satiety to the central nervous system and regulating energy balance is well recognized. But leptin also acts on peripheral tissues such as skeletal muscles, adipose tissues, pancreas, liver, intestine and the immune system. The existence of different splice variants of leptin receptor and the numerous intracellular signaling pathways triggered by leptin make this a truly versatile system. Two recent studies explore the link between malnutrition, leptin signaling and susceptibility to amebic infection. These studies point to important and novel aspects of leptin signaling in maintaining gut homeostasis and warding off infections.

Is There an Association Between Lumbosacral Radiculopathy and Painful Gluteal Trigger Points?: A Cross-sectional Study.

PubMed

Adelmanesh, Farhad; Jalali, Ali; Jazayeri Shooshtari, Seyed Mostafa; Raissi, Gholam Reza; Ketabchi, Seyed Mehdi; Shir, Yoram

2015-10-01

The objective of this study was to compare the prevalence of gluteal trigger point in patients with lumbosacral radiculopathy with that in healthy volunteers. In a cross-sectional, multistage sampling method, patients with clinical, electromyographic, and magnetic resonance imaging findings consistent with lumbosacral radiculopathy were examined for the presence of gluteal trigger point. Age- and sex-matched clusters of healthy volunteers were selected as the control group. The primary outcome of the study was the presence or absence of gluteal trigger point in the gluteal region of the patients and the control group. Of 441 screened patients, 271 met all the inclusion criteria for lumbosacral radiculopathy and were included in the study. Gluteal trigger point was identified in 207 (76.4%) of the 271 patients with radiculopathy, compared with 3 (1.9%) of 152 healthy volunteers (P < 0.001). The location of gluteal trigger point matched the side of painful radiculopathy in 74.6% of patients with a unilateral radicular pain. There was a significant correlation between the side of the gluteal trigger point and the side of patients' radicular pain (P < 0.001). Although rare in the healthy volunteers, most of the patients with lumbosacral radiculopathy had gluteal trigger point, located at the painful side. Further studies are required to test the hypothesis that specific gluteal trigger point therapy could be beneficial in these patients.

Role of calcium in triggering rapid ultrastructural damage in muscle: a study with chemically skinned fibres.

PubMed

Duncan, C J

1987-05-01

Agents (A23187, caffeine) believed to raise [Ca]i in vertebrate cardiac and skeletal muscles cause rapid and characteristic subcellular damage in vitro and in vivo. By using saponin-skinned amphibian pectoris cutaneous muscle and Ca-EGTA-buffered solutions it is shown that low [Ca] consistently triggers the same rapid (2-20 min), ultrastructural damage. Electron micrographs reveal a close similarity between the damaged intact and skinned preparations, namely loss of myofilament organization, specific Z-line damage, dissolution and hypercontraction bands, characteristic mitochondrial swelling and division. Where both actin and myosin filaments were lost, an underlying cytoskeletal network frequently remained, still attached to the Z-line framework. Ca was effective in skinned preparations from 5 X 10(-7) M to 8 X 10(-6) M, within the concentration range experienced by a contracting muscle. Damage was [Ca]- and time-dependent and it is suggested that it is probably the active movement of Ca ions across key membrane sites that is critical in triggering damage of the myofilament apparatus. Strontium can substitute for Ca at higher concentrations. The action of saponin suggests that the chemically skinned cell is partially activated. Ca-triggering can be bypassed experimentally by membrane-active agents or by sulphydryl agents. Ruthenium Red and trifluoperazine indirectly cause damage in the intact cell by raising [Ca]i. Studies with saponin-skinned cells and protease inhibitors show that changes in pHi, loss of ATP, Ca-activated neutral protease, or release of lysosomal enzymes (cathepsins B, D, L or H), are not involved in characteristic rapid myofilament damage.

Central mechanisms of stress-induced headache.

PubMed

Cathcart, S; Petkov, J; Winefield, A H; Lushington, K; Rolan, P

2010-03-01

Stress is the most commonly reported trigger of an episode of chronic tension-type headache (CTTH); however, the causal significance has not been experimentally demonstrated to date. Stress may trigger CTTH through hyperalgesic effects on already sensitized pain pathways in CTTH sufferers. This hypothesis could be partially tested by examining pain sensitivity in an experimental model of stress-induced headache in CTTH sufferers. Such examinations have not been reported to date. We measured pericranial muscle tenderness and pain thresholds at the finger, head and shoulder in 23 CTTH sufferers (CTH-S) and 25 healthy control subjects (CNT) exposed to an hour-long stressful mental task, and in 23 CTTH sufferers exposed to an hour-long neutral condition (CTH-N). Headache developed in 91% of CTH-S, 4% of CNT, and 17% of CTH-N subjects. Headache sufferers had increased muscle tenderness and reduced pain thresholds compared with healthy controls. During the task, muscle tenderness increased and pain thresholds decreased in the CTH-S group compared with CTH-N and CNT groups. Pre-task muscle tenderness and reduction in pain threshold during task were predictive of the development and intensity of headache following task. The main findings are that stress induced a headache in CTTH sufferers, and this was associated with pre-task muscle tenderness and stress-induced reduction in pain thresholds. The results support the hypothesis that stress triggers CTTH through hyperalgesic effects on already increased pain sensitivity in CTTH sufferers, reducing the threshold to noxious input from pericranial structures.

Amino Acid Sensing in Skeletal Muscle

PubMed Central

Moro, Tatiana; Ebert, Scott M.; Adams, Christopher M.; Rasmussen, Blake B.

2016-01-01

Aging impairs skeletal muscle protein synthesis, leading to muscle weakness and atrophy. However, the underlying molecular mechanisms remain poorly understood. Here, we review evidence that mTORC1- and ATF4-mediated amino acid sensing pathways, triggered by impaired amino acid delivery to aged skeletal muscle, may play important roles in skeletal muscle aging. Interventions that alleviate age-related impairments in muscle protein synthesis, strength and/or muscle mass appear to do so by reversing age-related changes in skeletal muscle amino acid delivery, mTORC1 activity and/or ATF4 activity. An improved understanding of the mechanisms and roles of amino acid sensing pathways in skeletal muscle may lead to evidence-based strategies to attenuate sarcopenia. PMID:27444066

The face of pain--a pilot study to validate the measurement of facial pain expression with an improved electromyogram method.

PubMed

Wolf, Karsten; Raedler, Thomas; Henke, Kai; Kiefer, Falk; Mass, Reinhard; Quante, Markus; Wiedemann, Klaus

2005-01-01

The purpose of this pilot study was to establish the validity of an improved facial electromyogram (EMG) method for the measurement of facial pain expression. Darwin defined pain in connection with fear as a simultaneous occurrence of eye staring, brow contraction and teeth chattering. Prkachin was the first to use the video-based Facial Action Coding System to measure facial expressions while using four different types of pain triggers, identifying a group of facial muscles around the eyes. The activity of nine facial muscles in 10 healthy male subjects was analyzed. Pain was induced through a laser system with a randomized sequence of different intensities. Muscle activity was measured with a new, highly sensitive and selective facial EMG. The results indicate two groups of muscles as key for pain expression. These results are in concordance with Darwin's definition. As in Prkachin's findings, one muscle group is assembled around the orbicularis oculi muscle, initiating eye staring. The second group consists of the mentalis and depressor anguli oris muscles, which trigger mouth movements. The results demonstrate the validity of the facial EMG method for measuring facial pain expression. Further studies with psychometric measurements, a larger sample size and a female test group should be conducted.

Scapular instability associated with brachial plexus irritation: a proposed causative relationship with treatment implications.

PubMed

Langley, P

1997-01-01

Brachial plexus irritation and other compression neuropathies can be diverse in their presentations and can cause a myriad of signs and symptoms. The purpose of this paper is to review the pertinent anatomy, kinesiology, and neurophysiology and to outline one possible cascade of events that may contribute to more diffuse upper extremity symptoms. Scapular instability and local myofascial trigger points resulting in possible secondary muscle imbalances are described. Their possible relationship to brachial plexus irritation in addition to the implications of the irritation are also discussed. The author postulates that proximal nerve irritation in the region of the thoracic outlet and shoulder may help to account for diffuse or unrelieved symptoms following conventional treatment of distal extremity problems in patients with occupational or cumulative trauma disorders. This paper outlines specific examination procedures for the therapist, which include upper limb tension testing, extensibility testing of the pectoralis minor, and gross manual muscle testing of the lower trapezius.

[Core muscle chains activation during core exercises determined by EMG-a systematic review].

PubMed

Rogan, Slavko; Riesen, Jan; Taeymans, Jan

2014-10-15

Good core muscles strength is essential for daily life and sports activities. However, the mechanism how core muscles may be effectively triggered by exercises is not yet precisely described in the literature. The aim of this systematic review was to evaluate the rate of activation as measured by electromyography of the ventral, lateral and dorsal core muscle chains during core (trunk) muscle exercises. A total of 16 studies were included. Exercises with a vertical starting position, such as the deadlift or squat activated significantly more core muscles than exercises in the horizontal initial position.

Botulinum Toxin for the Treatment of Myofascial Pain Syndromes Involving the Neck and Back: A Review from a Clinical Perspective

PubMed Central

Climent, José M.; Fenollosa, Pedro; Martin-del-Rosario, Francisco

2013-01-01

Introduction. Botulinum toxin inhibits acetylcholine (ACh) release and probably blocks some nociceptive neurotransmitters. It has been suggested that the development of myofascial trigger points (MTrP) is related to an excess release of ACh to increase the number of sensitized nociceptors. Although the use of botulinum toxin to treat myofascial pain syndrome (MPS) has been investigated in many clinical trials, the results are contradictory. The objective of this paper is to identify sources of variability that could explain these differences in the results. Material and Methods. We performed a content analysis of the clinical trials and systematic reviews of MPS. Results and Discussion. Sources of differences in studies were found in the diagnostic and selection criteria, the muscles injected, the injection technique, the number of trigger points injected, the dosage of botulinum toxin used, treatments for control group, outcome measures, and duration of followup. The contradictory results regarding the efficacy of botulinum toxin A in MPS associated with neck and back pain do not allow this treatment to be recommended or rejected. There is evidence that botulinum toxin could be useful in specific myofascial regions such as piriformis syndrome. It could also be useful in patients with refractory MPS that has not responded to other myofascial injection therapies. PMID:23533477

Lidocaine Injection in the Intramuscular Innervation Zone Can Effectively Treat Chronic Neck Pain Caused by MTrPs in the Trapezius Muscle.

PubMed

Xie, Peng; Qin, Bangyong; Yang, Fangjiu; Yu, Tian; Yu, Jin; Wang, Jiang; Zheng, Hong

2015-01-01

An increasing number of people suffer from neck pain due to life style and prolonged use of computers. Research has revealed that myofascial trigger points (MTrPs) and the intramuscular innervation zone (IZ) are involved in neck pain. MTrPs are induced mainly by IZ dysfunction of the affected skeletal muscle and the 2 do not overlap in location. The question is whether injection treatment in MTrPs or in the IZ is more effective to relieve MTrPs-associated pains. The precise location and body-surface map of the intramuscular IZ in the trapezius muscle and a clinical injection study in the IZ may provide a useful answer to the question. This study aimed to investigate the efficacy of lidocaine injection in the intramuscular IZ for the treatment of chronic neck pain caused by MTrPs in the trapezius muscle. Prospective observational study, approved by the local research ethics. University hospital, departments of Anesthesiology and Anatomy. First, for the determination of IZ distribution and body-surface mapping, a modified intramuscular Sihler's neural staining technique was applied to elucidate nerve distribution patterns of the trapezius muscle. Then, 120 patients with myofascial pain syndrome (MPS) of the trapezius muscle were randomly divided into 5 groups for analysis. Group 1 (n = 24) received injections of saline (0.9% NaCl) at the MTrPs. Group 2 (n = 24) received injections of 0.5% lidocaine at the MTrPs. Group 3 (n = 24) received injections of saline (0.9% NaCl) at the mid-upper trapezius (Point E). Group 4 (n = 24) received injections of 0.5% lidocaine at Point E. Group 5 (n = 24) received a combined injection of 0.5% lidocaine treatment at both Point E and the lower trapezius (Point F). The injection dose was 4 mL at each injection site. All patients received injections once a week for 4 weeks. The visual analogue scale (VAS) and the frequency of painful days per month (FPD) were obtained before treatment and at 2, 4, and 6 months after treatment. The intramuscular terminal nerve branches presented a "dendritic" distribution in the trapezius muscle and were connected with each other to form an S-shaped IZ belt in the middle of the muscle belly. Compared with the MTrP injection group, lidocaine-injection therapy in the IZ significantly reduced the degree and frequency of neck pain in patients at 6 months after treatment, especially the combined lidocaine-injection therapy in the IZ of both the mid-upper trapezius and the lower trapezius are more effective (all P < 0.05). This study confirms that lidocaine-injection therapy in the IZ significantly reduces the degree and frequency of neck pain in patients at 6 months after treatment. The combined lidocaine-injection therapy in the IZ of both the mid-upper trapezius and the lower trapezius is more effective. In addition, this study establishes a clear distribution map of intramuscular nerves that will be conducive to the future use of chemical blockers and electrical stimulation in the nervous system in treating MPS of the trapezius muscle. The small number of patients and the short duration of follow-up.

Crossed motor innervation of the base of human tongue

PubMed Central

Jordan, Amy S.; Nicholas, Christian L.; Cori, Jennifer M.; Semmler, John G.; Trinder, John

2015-01-01

Muscle fibers of the genioglossus (GG) form the bulk of the muscle mass at the base of the tongue. The motor control of the tongue is critical for vocalization, feeding, and breathing. Our goal was to assess the patterns of motor innervation of GG single motor units (SMUs) in humans. Simultaneous monopolar recordings were obtained from four sites in the base of the tongue bilaterally at two antero-posterior levels from 16 resting, awake, healthy adult males, who wore a face mask with airway pressure and airflow sensors. We analyzed 69 data segments in which at least one lead contained large action potentials generated by an SMU. Such potentials served as triggers for spike-triggered averaging (STA) of signals recorded from the other three sites. Spontaneous activity of the SMUs was classified as inspiratory modulated, expiratory modulated, or tonic. Consistent with the antero-posterior orientation of GG fibers, 44 STAs (77%) recorded ipsilateral to the trigger yielded sharp action potentials with a median amplitude of 52 μV [interquartile range (IQR): 25–190] that were time shifted relative to the trigger by about 1 ms. Notably, 48% of recordings on the side opposite to the trigger also yielded sharp action potentials. Of those, 17 (29%) had a median amplitude of 63 μV (IQR: 39–96), and most were generated by tonic SMUs. Thus a considerable proportion of GG muscle fibers receive a crossed motor innervation. Crossed innervation may help ensure symmetry and stability of tongue position and movements under normal conditions and following injury or degenerative changes affecting the tongue. PMID:25855691

Probable Mechanisms of Needling Therapies for Myofascial Pain Control

PubMed Central

Chou, Li-Wei; Kao, Mu-Jung; Lin, Jaung-Geng

2012-01-01

Myofascial pain syndrome (MPS) has been defined as a regional pain syndrome characterized by muscle pain caused by myofascial trigger points (MTrPs) clinically. MTrP is defined as the hyperirritable spot in a palpable taut band of skeletal muscle fibers. Appropriate treatment to MTrPs can effectively relieve the clinical pain of MPS. Needling therapies, such as MTrP injection, dry needling, or acupuncture (AcP) can effectively eliminate pain immediately. AcP is probably the first reported technique in treating MPS patients with dry needling based on the Traditional Chinese Medicine (TCM) theory. The possible mechanism of AcP analgesia were studied and published in recent decades. The analgesic effect of AcP is hypothesized to be related to immune, hormonal, and nervous systems. Compared to slow-acting hormonal system, nervous system acts in a faster manner. Given these complexities, AcP analgesia cannot be explained by any single mechanism. There are several principles for selection of acupoints based on the TCM principles: “Ah-Shi” point, proximal or remote acupoints on the meridian, and extra-meridian acupoints. Correlations between acupoints and MTrPs are discussed. Some clinical and animal studies of remote AcP for MTrPs and the possible mechanisms of remote effectiveness are reviewed and discussed. PMID:23346211

Test-retest reliability of myofascial trigger point detection in hip and thigh areas.

PubMed

Rozenfeld, E; Finestone, A S; Moran, U; Damri, E; Kalichman, L

2017-10-01

Myofascial trigger points (MTrP's) are a primary source of pain in patients with musculoskeletal disorders. Nevertheless, they are frequently underdiagnosed. Reliable MTrP palpation is the necessary for their diagnosis and treatment. The few studies that have looked for intra-tester reliability of MTrPs detection in upper body, provide preliminary evidence that MTrP palpation is reliable. Reliability tests for MTrP palpation on the lower limb have not yet been performed. To evaluate inter- and intra-tester reliability of MTrP recognition in hip and thigh muscles. Reliability study. 21 patients (15 males and 6 females, mean age 21.1 years) referred to the physical therapy clinic, 10 with knee or hip pain and 11 with pain in an upper limb, low back, shin or ankle. Two experienced physical therapists performed the examinations, blinded to the subjects' identity, medical condition and results of the previous MTrP evaluation. Each subject was evaluated four times, twice by each examiner in a random order. Dichotomous findings included a palpable taut band, tenderness, referred pain, and relevance of referred pain to patient's complaint. Based on these, diagnosis of latent MTrP's or active MTrP's was established. The evaluation was performed on both legs and included a total of 16 locations in the following muscles: rectus femoris (proximal), vastus medialis (middle and distal), vastus lateralis (middle and distal) and gluteus medius (anterior, posterior and distal). Inter- and intra-tester reliability (Cohen's kappa (κ)) values for single sites ranged from -0.25 to 0.77. Median intra-tester reliability was 0.45 and 0.46 for latent and active MTrP's, and median inter-tester reliability was 0.51 and 0.64 for latent and active MTrPs, respectively. The examination of the distal vastus medialis was most reliable for latent and active MTrP's (intra-tester k = 0.27-0.77, inter-tester k = 0.77 and intra-tester k = 0.53-0.72, inter-tester k = 0.72, correspondingly). Inter- and intra-tester reliability of active and latent MTrP evaluation was moderate to substantial. Palpation evaluation can be used for clinical diagnosis of MTrP's in the hip and thigh muscles. This study provides evidence that MTrP palpation is a moderately reliable diagnostic tool in the hip and thigh muscles and can be used in clinical practice and research. Copyright © 2017 Elsevier Ltd. All rights reserved.

The postural control can be optimized by the first movement initiation condition encountered when submitted to muscle fatigue.

PubMed

Monjo, Florian; Forestier, Nicolas

2017-08-01

We investigated whether and how the movement initiation condition (IC) encountered during the early movements performed following focal muscle fatigue affects the postural control of discrete ballistic movements. For this purpose, subjects performed shoulder flexions in a standing posture at maximal velocity under two movement IC, i.e., in self-paced conditions and submitted to a Stroop-like task in which participants had to trigger fast shoulder flexions at the presentation of incongruent colors. Shoulder flexion kinematics, surface muscle activity of focal and postural muscles as well as center-of-pressure kinematics were recorded. The initial IC and the order in which subjects were submitted to these two conditions were varied within two separate experimental sessions. IC schedule was repeated before and after fatigue protocols involving shoulder flexors. The aim of this fatigue procedure was to affect acceleration-generating capacities of focal muscles. In such conditions, the postural muscle activity preceding and accompanying movement execution is expected to decrease. Following fatigue, when subjects initially moved in self-paced conditions, postural muscle activity decreased and scaled to the lower focal peak acceleration. This postural strategy then transferred to the Stroop-like task. In contrast, when subjects initially moved submitted to the Stroop-like task, postural muscle activity did not decrease and this transferred to self-paced movements. Regarding the center-of-pressure peak velocity, which is indicative of the efficiency of the postural actions generated in stabilizing posture, no difference appeared between the two sessions post-fatigue. This highlights an optimization of the postural actions when subjects first moved in self-paced conditions, smaller postural muscle activation levels resulting in similar postural consequences. In conclusion, the level of neuromuscular activity associated with the postural control is affected and can be optimized by the initial movement IC experienced post-fatigue. Beyond the fundamental contributions arising from these results, we point out potential applications for trainers and sports instructors. Copyright © 2017 Elsevier B.V. All rights reserved.

What triggers the continuous muscle activity during upright standing?

PubMed

Masani, Kei; Sayenko, Dimitry G; Vette, Albert H

2013-01-01

The ankle extensors play a dominant role in controlling the equilibrium during bipedal quiet standing. Their primary role is to resist the gravity toppling torque that pulls the body forward. The purpose of this study was to investigate whether the continuous muscle activity of the anti-gravity muscles during standing is triggered by the joint torque requirement for opposing the gravity toppling torque, rather than by the vertical load on the lower limbs. Healthy adults subjects stood on a force plate. The ankle torque, ankle angle, and electromyograms from the right lower leg muscles were measured. A ground-fixed support device was used to support the subject at his/her knees, without changing the posture from the free standing one. During the supported condition, which eliminates the ankle torque requirement while maintaining both the vertical load on the lower limbs and the natural upright standing posture, the plantarflexor activity was attenuated to the resting level. Also, this attenuated plantarflexor activity was found only in one side when the ipsilateral leg was supported. Our results suggest that the vertical load on the lower limb is not determinant for inducing the continuous muscle activity in the anti-gravity muscles, but that it depends on the required joint torque to oppose the gravity toppling torque. Copyright © 2012 Elsevier B.V. All rights reserved.

Detection of the electromechanical delay and its components during voluntary isometric contraction of the quadriceps femoris muscle.

PubMed

Begovic, Haris; Zhou, Guang-Quan; Li, Tianjie; Wang, Yi; Zheng, Yong-Ping

2014-01-01

Electromechanical delay (EMD) was described as a time elapsed between first trigger and force output. Various results have been reported based on the measurement method with observed inconsistent results when the trigger is elicited by voluntary contraction. However, mechanomyographic (MMG) sensor placed far away on the skin from the contracting muscle was used to detect muscle fiber motion and excitation-contraction (EC) coupling which may give unreliable results. On this basis, the purpose of this study was to detect EMD during active muscle contraction whilst introducing an ultrafast ultrasound (US) method to detect muscle fiber motion from a certain depth of the muscle. Time delays between onsets of EMG-MMG, EMG-US, MMG-FORCE, US-FORCE, and EMG-FORCE were calculated as 20.5 ± 4.73, 28.63 ± 6.31, 19.21 ± 6.79, 30.52 ± 8.85, and 49.73 ± 6.99 ms, respectively. Intrarater correlation coefficient (ICC) was higher than MMG when ultrafast US was used for detecton of the Δt EMG-US and Δt US-FORCE, ICC values of 0.75 and 0.70, respectively. Synchronization of the ultrafast ultrasound with EMG and FORCE sensors can reveal reliable and clinically useful results related to the EMD and its components when muscle is voluntarily contracted. With ultrafast US, we detect onset from the certain depth of the muscle excluding the tissues above the muscle acting as a low-pass filter which can lead to inaccurate time detection about the onset of the contracting muscle fibers. With this non-invasive technique, understanding of the muscle dynamics can be facilitated.

Relationship of active trigger points with related disability and anxiety in people with tension-type headache

PubMed Central

Palacios-Ceña, María; Castaldo, Matteo; Wang, Kelun; Catena, Antonella; Torelli, Paola; Arendt-Nielsen, Lars; Fernández-de-las-Peñas, César

2017-01-01

Abstract To investigate the differences in the presence of trigger points (TrPs) and their association with headache-related disability and mood disorders in people with frequent episodic tension-type headache (TTH) (FETTH) and chronic TTH (CTTH). One hundred twenty-two individuals with TTH participated. Clinical features of headache (i.e., intensity, duration, and frequency) were recorded on a headache diary. Headache-related disability was assessed with the Headache Disability Inventory, trait and state anxiety levels with State-Trait Anxiety Inventory, and depression with the Hospital Anxiety and Depression Scale. TrPs were bilaterally explored in the temporalis, masseter, suboccipital, upper trapezius, splenius capitis, and sternocleidomastoid muscles. Sixty-two (51%) patients were classified as FETTH, whereas 60 (49%) were classified as CTTH. Individuals with CTTH showed higher burden of headache and depression than FETTH (P < 0.001). Subjects with FETTH showed similar number of TrPs (total number: 5.9 ± 3.1, active TrPs: 4.7 ± 2.5, and latent TrPs: 1.2 ± 1.9) than those with CTTH (total number: 5.7 ± 3.2, active TrPs: 4.2 ± 3.0, and latent TrPs: 1.5 ± 1.8). The number of active TrPs was significantly associated with the burden of headache (r = 0.189; P = 0.037) and trait anxiety (r = 0.273; P = 0.005): the higher the number of active TrPs, the greater the physical burden of headache or the more the trait anxiety level. No association with the depression was observed. The presence of active TrPs in head and neck/shoulder muscles was similar between individuals with FETTH and CTTH and associated with the physical burden of headache and trait anxiety levels independently of the subgroup of TTH. PMID:28353618

TREATMENT OF SUBACUTE POSTERIOR KNEE PAIN IN AN ADOLESCENT BALLET DANCER UTILIZING TRIGGER POINT DRY NEEDLING: A CASE REPORT

PubMed Central

Tansey, Kimberly A.; Westrick, Richard B.

2014-01-01

Study Design: Case Report. Background and Purpose: Dry needling (DN) is an increasingly popular intervention used by clinicians as a treatment of regional neuromusculoskeletal pain. DN is an invasive procedure that involves insertion of a thin monofilament needle directly into a muscle trigger point (MTP) with the intent of stimulating a local twitch response. Current evidence is somewhat limited, but recent literature supports the use of this intervention in specific neuromusculoskeletal conditions. The purpose of this case report is to present the outcomes of DN as a primary treatment intervention in an adolescent subject with subacute posterior knee pain. Case Description: The subject was a 16‐year‐old female competitive ballet dancer referred to physical therapy with a two month history of right posterior knee pain. Palpation identified MTPs which reproduced the patient’s primary symptoms. In addition to an exercise program promoting lower extremity flexibility and hip stability, the subject was treated with DN to the right gastrocnemius, soleus, and popliteus muscles. Outcomes: The subject reported being pain free on the Numerical Pain Scale and a +7 improvement in perceived change in recovery on the Global Rating of Change at final follow‐up. Physical examination demonstrated no observed impairments or functional limitations, including normal mobility, full strength, and unrestricted execution of dance maneuvers. Discussion: The patient was able to return to high level dance training and competition without physical limitations and resumed pre‐injury dynamic movement activities including dancing, running, jumping, and pivoting without pain. DN can be an effective and efficient intervention to assist patients in decreasing pain and returning to high intensity physical activity. Additional research is needed to determine if DN is effective for other body regions and has long‐term positive outcomes. Level of Evidence: Level 4 PMID:24567862

Conservative chiropractic management of urinary incontinence using applied kinesiology: a retrospective case-series report.

PubMed

Cuthbert, Scott C; Rosner, Anthony L

2012-03-01

The purpose of this case series is to describe the chiropractic management of 21 patients with daily stress and occasional total urinary incontinence (UI). Twenty-one case files of patients 13 to 90 years of age with UI from a chiropractic clinic were reviewed. The patients had a 4-month to 49-year history of UI and associated muscle dysfunction and low back and/or pelvic pain. Eighteen wore an incontinence pad throughout the day and night at the time of their appointments because of unpredictable UI. Patients were evaluated for muscle impairments in the lumbar spine, pelvis, and pelvic floor and low back and/or hip pain. Positive manual muscle test results of the pelvis, lumbar spine muscles, and pelvic floor muscles were the most common findings. Lumbosacral dysfunction was found in 13 of the cases with pain provocation tests (applied kinesiology sensorimotor challenge); in 8 cases, this sensorimotor challenge was absent. Chiropractic manipulative therapy and soft tissue treatment addressed the soft tissue and articular dysfunctions. Chiropractic manipulative therapy involved high-velocity, low-amplitude manipulation; Cox flexion distraction manipulation; and/or use of a percussion instrument for the treatment of myofascial trigger points. Urinary incontinence symptoms resolved in 10 patients, considerably improved in 7 cases, and slightly improved in 4 cases. Periodic follow-up examinations for the past 6 years, and no less than 2 years, indicate that for each participant in this case-series report, the improvements of UI remained stable. The patients reported in this retrospective case series showed improvement in UI symptoms that persisted over time.

The Sick and the Weak: Neuropathies/Myopathies in the Critically Ill

PubMed Central

Friedrich, O.; Reid, M. B.; Van den Berghe, G.; Vanhorebeek, I.; Hermans, G.; Rich, M. M.; Larsson, L.

2015-01-01

Critical illness polyneuropathies (CIP) and myopathies (CIM) are common complications of critical illness. Several weakness syndromes are summarized under the term intensive care unit-acquired weakness (ICUAW). We propose a classification of different ICUAW forms (CIM, CIP, sepsis-induced, steroid-denervation myopathy) and pathophysiological mechanisms from clinical and animal model data. Triggers include sepsis, mechanical ventilation, muscle unloading, steroid treatment, or denervation. Some ICUAW forms require stringent diagnostic features; CIM is marked by membrane hypoexcitability, severe atrophy, preferential myosin loss, ultrastructural alterations, and inadequate autophagy activation while myopathies in pure sepsis do not reproduce marked myosin loss. Reduced membrane excitability results from depolarization and ion channel dysfunction. Mitochondrial dysfunction contributes to energy-dependent processes. Ubiquitin proteasome and calpain activation trigger muscle proteolysis and atrophy while protein synthesis is impaired. Myosin loss is more pronounced than actin loss in CIM. Protein quality control is altered by inadequate autophagy. Ca2+ dysregulation is present through altered Ca2+ homeostasis. We highlight clinical hallmarks, trigger factors, and potential mechanisms from human studies and animal models that allow separation of risk factors that may trigger distinct mechanisms contributing to weakness. During critical illness, altered inflammatory (cytokines) and metabolic pathways deteriorate muscle function. ICUAW prevention/treatment is limited, e.g., tight glycemic control, delaying nutrition, and early mobilization. Future challenges include identification of primary/secondary events during the time course of critical illness, the interplay between membrane excitability, bioenergetic failure and differential proteolysis, and finding new therapeutic targets by help of tailored animal models. PMID:26133937

Spatial and temporal profile of cisplatin delivery by ultrasound-assisted intravesical chemotherapy in a bladder cancer model.

PubMed

Sasaki, Noboru; Ishi, Kazuhiro; Kudo, Nobuki; Nakayama, Shouta M M; Nakamura, Kensuke; Morishita, Keitaro; Ohta, Hiroshi; Ishizuka, Mayumi; Takiguchi, Mitsuyoshi

2017-01-01

Non-muscle invasive bladder cancer is one of the most common tumors of the urinary tract. Despite the current multimodal therapy, recurrence and progression of disease have been challenging problems. We hereby introduced a new approach, ultrasound-assisted intravesical chemotherapy, intravesical instillation of chemotherapeutic agents and microbubbles followed by ultrasound exposure. We investigated the feasibility of the treatment for non-muscle invasive bladder cancer. In order to evaluate intracellular delivery and cytotoxic effect as a function to the thickness, we performed all experiments using a bladder cancer mimicking 3D culture model. Ultrasound-triggered microbubble cavitation increased both the intracellular platinum concentration and the cytotoxic effect of cisplatin at the thickness of 70 and 122 μm of the culture model. The duration of enhanced cytotoxic effect of cisplatin by ultrasound-triggered microbubble cavitation was approximately 1 hr. Based on the distance and duration of delivery, we further tested the feasibility of repetition of the treatment. Triple treatment increased the effective distance by 1.6-fold. Our results clearly showed spatial and temporal profile of delivery by ultrasound-triggered microbubble cavitation in a tumor-mimicking structure. Furthermore, we demonstrated that the increase in intracellular concentration results in the enhancement of the cytotoxic effect in a structure with the certain thickness. Repetition of ultrasound exposure would be treatment of choice in future clinical application. Our results suggest ultrasound-triggered microbubble cavitation can be repeatable and is promising for the local control of non-muscle invasive bladder cancer.

Two- and three-dimensional ultrasound imaging to facilitate detection and targeting of taut bands in myofascial pain syndrome.

PubMed

Shankar, Hariharan; Reddy, Sapna

2012-07-01

Ultrasound imaging has gained acceptance in pain management interventions. Features of myofascial pain syndrome have been explored using ultrasound imaging and elastography. There is a paucity of reports showing the benefit clinically. This report provides three-dimensional features of taut bands and highlights the advantages of using two-dimensional ultrasound imaging to improve targeting of taut bands in deeper locations. Fifty-eight-year-old man with pain and decreased range of motion of the right shoulder was referred for further management of pain above the scapula after having failed conservative management for myofascial pain syndrome. Three-dimensional ultrasound images provided evidence of aberrancy in the architecture of the muscle fascicles around the taut bands compared to the adjacent normal muscle tissue during serial sectioning of the accrued image. On two-dimensional ultrasound imaging over the palpated taut band, areas of hyperechogenicity were visualized in the trapezius and supraspinatus muscles. Subsequently, the patient received ultrasound-guided real-time lidocaine injections to the trigger points with successful resolution of symptoms. This is a successful demonstration of utility of ultrasound imaging of taut bands in the management of myofascial pain syndrome. Utility of this imaging modality in myofascial pain syndrome requires further clinical validation. Wiley Periodicals, Inc.

[Analysis of palpation laws of muscle meridian focus on knee osteoarthritis].

PubMed

Zhang, Shu-Jian; Zhang, Xiao-Qing; Han, Yu; Li, Chun-Ri; Dong, Bao-Qiang

2012-03-01

To explore the distribution regulars of proximal and distal focus of muscle meridian regions in knee osteoarthritis patients. Seven hundred and sixty-five knees were selected in 516 cases of knee osteoarthritis. Under the guidance of muscle meridian theory, with the anatomical features of muscle meridian focus, the frequency and the location where the proximal and distal focus of muscle meridian regions appeared were calculated by palpation. Of all the points, 11 835 points of proximal focus of muscle meridian regions were found out by palpation, and 9455 points of distal focus of muscle meridian regions were found out. The percentages of the frequency that the focus of muscle meridian of Foot-Yangming, Foot-Taiyang, Foot-Shaoyang and three foot Yin meridians appeared at proximal points of knee were 37.1% (4388/11 835), 34.9% (4127/11 835), 9.5% (1129/11 835) and 18.5% (2191/11 835) respectively; and the percentage of the frequency that the focus of muscle meridian appeared at distal points of knee were 24.7% (2333/9455), 25.2% (2380/9455), 28.5% (2700/9455) and 21.6% (2042/9455). The proximal and distal focus of muscle meridian in knee osteoarthritis patients are closely related with anatomy structure and biomechanical characteristics; the distribution regulars of focus of muscle meridians study provides evidence for the selection of effective treatment points from different clinical acupuncture therapies.

Trends in management of myofacial pain

PubMed Central

Pal, Uma Shanker; Kumar, Lakshya; Mehta, Gagan; Singh, Nimisha; Singh, Geeta; Singh, Mayank; Yadav, Hemant Kumar

2014-01-01

We systematically reviewed the myofascial pain publications in the literature. The aim of this article is to review the methods of management and their outcome and factors associated with prognosis. The topics of interest in the diagnostic process are myofascial trigger points electromyography, jaw tracking, joint sound recorder, sonography, and vibratography, exclusion of other orofacial pain and temporomandibular disorders. Management modalities are occlusal therapy, physiotherapy, multidimensional rehabilitation antinociceptive therapy, anti-inflammatory and analgesics, muscle relaxants, stretch, and spray technique, transcutaneous electric nerve stimulation, and in severe cases botulinum toxin may be tried. The disease required interdisciplinary interaction in terms of occlusal therapy, antinociceptive therapy and physiotherapy because management of the disease may be influenced by the specialist primarily treating the patients. PMID:25937719

Research on the effects of laser-therapy application in low back pain of musculo-capsulo-ligaments disorders

NASA Astrophysics Data System (ADS)

Nica, Adriana S.; Teleki, N.; Vasiliu, Virgil V.

1995-03-01

Usually, lumbosacrat aria is a very mechanical stressed aria because of insufficient adaptation to the verticality and because of many other getting in professional field (high physical stress, sedentary profession) or in daily living. Because of all these facts and the other can develop `low back pain syndromes' in variable places dorsolumbar, lumbar or lumbosacrat aria, in different degree of disability interesting the muscles, fasciae, aponevrosis tendons, capsules and ligaments. Specially the muscular tissue is in high sufferings in paravertebral lumbosacrat place where we can find frequently contractor (usually secondary to the static vertebral troubles) or retractors; sometimes we discover morphopathological disorder in muscles with trigger and tender points--very painful and cause of a high percent of disability of lumbosacrat region. The aim of this research is to prove by clinic--functional tests the effects of laser- therapy and to notice the answer of all the soft tissue from lumbosacrat region and all the structures treated which respond after laser-therapy to kinetotherapy, comparing with the other kinds of physical therapy.

A critical overview of the current myofascial pain literature - March 2016.

PubMed

Dommerholt, Jan; Hooks, Todd; Finnegan, Michelle; Grieve, Rob

2016-04-01

The worldwide interest in myofascial pain syndrome (MPS) and trigger points (TrPs) is reflected in the increasing number of publications. In this overview of the literature, we included 26 studies, case reports and review articles by authors from 18 different countries. Several research groups are exploring the characteristic of TrPs such as Chen and colleagues, who continued their work on the quantification of the taut bands. Meng and colleagues studied the relationships between TrPs and central sensitization, while Yu and colleagues examined the electrophysiological characteristics that occur as a result of active TrPs. Several researchers used objective measurements to determine clinical outcomes, such as Koppenhaver and colleagues who measured objective changes in the function and nociceptive sensitivity of lumbar multifidus muscle subjects with low back pain. Turo and colleagues quantified muscle tissue changes after dry needling in chronic myofascial pain using elastography. Multiple studies explored various treatment options for TrPs, such as dry needling, injections with lidocaine or granisetron, traditional Thai massage, self-myofascial release, kinesiotaping, and monochromatic infrared photo energy, among others. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reliability of assessment of upper trapezius morphology, its mechanical properties and blood flow in female patients with myofascial pain syndrome using ultrasonography.

PubMed

Adigozali, Hakimeh; Shadmehr, Azadeh; Ebrahimi, Esmail; Rezasoltani, Asghar; Naderi, Farrokh

2017-01-01

In the present study, the intra-rater reliability of upper trapezius morphology, its mechanical properties and intramuscular blood circulation in females with myofascial pain syndrome were assessed using ultrasonography. A total of 37 patients (31.05 ± 10 years old) participated in this study. Ultrasonography producer was set up in three stages: a) Gray-scale: to measure muscle thickness, size and area of trigger points; b) Ultrasound elastography: to measure muscle stiffness; and c) Doppler imaging: to assess blood flow indices. According to data analysis, all variables, except End Diastolic Velocity (EDV), had excellent reliability (>0.806). Intra-class Correlation Coefficient (ICC) for EDV was 0.738, which was considered a poor to good reliability. The results of this study introduced a reliable method for developing details of upper trapezius features using muscular ultrasonography in female patients. These variables could be used for objective examination and provide guidelines for treatment plans in clinical settings. Copyright © 2016 Elsevier Ltd. All rights reserved.

Aerobic Exercise and Pharmacological Treatments Counteract Cachexia by Modulating Autophagy in Colon Cancer

PubMed Central

Pigna, Eva; Berardi, Emanuele; Aulino, Paola; Rizzuto, Emanuele; Zampieri, Sandra; Carraro, Ugo; Kern, Helmut; Merigliano, Stefano; Gruppo, Mario; Mericskay, Mathias; Li, Zhenlin; Rocchi, Marco; Barone, Rosario; Macaluso, Filippo; Di Felice, Valentina; Adamo, Sergio; Coletti, Dario; Moresi, Viviana

2016-01-01

Recent studies have correlated physical activity with a better prognosis in cachectic patients, although the underlying mechanisms are not yet understood. In order to identify the pathways involved in the physical activity-mediated rescue of skeletal muscle mass and function, we investigated the effects of voluntary exercise on cachexia in colon carcinoma (C26)-bearing mice. Voluntary exercise prevented loss of muscle mass and function, ultimately increasing survival of C26-bearing mice. We found that the autophagic flux is overloaded in skeletal muscle of both colon carcinoma murine models and patients, but not in running C26-bearing mice, thus suggesting that exercise may release the autophagic flux and ultimately rescue muscle homeostasis. Treatment of C26-bearing mice with either AICAR or rapamycin, two drugs that trigger the autophagic flux, also rescued muscle mass and prevented atrogene induction. Similar effects were reproduced on myotubes in vitro, which displayed atrophy following exposure to C26-conditioned medium, a phenomenon that was rescued by AICAR or rapamycin treatment and relies on autophagosome-lysosome fusion (inhibited by chloroquine). Since AICAR, rapamycin and exercise equally affect the autophagic system and counteract cachexia, we believe autophagy-triggering drugs may be exploited to treat cachexia in conditions in which exercise cannot be prescribed. PMID:27244599

Support afferentation in the posture and locomotion control system

NASA Astrophysics Data System (ADS)

Grigoriev, Anatoly; Tomilovskaya, Elena; Kozlovskaya, Inesa

Mechanisms of support afferentation contribution in posture and locomotion control, which were uncertain up to now, became the point of intensive studies recently. This became possible since the space flights era started which created the conditions for simulated microgravity experiments under conditions of dry immersion and bedrest. The results of neurophysiological studies performed under the conditions of supportlessness have shown that decline or elimination of support loads is followed by deep and fast developing alterations in postural tonic system, including development of postural muscle atonia, changes of recruitment order of motoneurons innervating the shin muscles, spinal hyperreflexia development etc. (Kozlovskaya I.B. et al., 1987). It has been also shown that application of artificial support stimulation in the regimen of natural locomotion under these conditions decreases significantly or even eliminates the development of mentioned changes. The results of these studies laid down the basis for a new hypothesis on the trigger role of support afferentation in postural tonic system and its role in organization and control of postural synergies (Grigoriev A.I. et al., 2004). According to this hypothesis the muscle reception is considered to be the leading afferent input in the control of locomotion. However the data of recent studies pointed out strongly to the participation of support afferentation in definition of cognitive strategies and motor programs of locomotor movements (Chernikova L.A. et al., 2013) and, consequently, in the processes of their initiation (Gerasimenko Yu.P. et al., 2012). The cortical locomotor reflex composes apparently the basis of these processes. The receptive field of this reflex is located in the support zones of the soles and the central part is located in the posterior parietal areas (IPL) of brain cortex. The study is supported by RFBR grant N 13-04-12091 OFI-m.

Tropomodulin isoforms regulate thin filament pointed-end capping and skeletal muscle physiology

PubMed Central

Gokhin, David S.; Lewis, Raymond A.; McKeown, Caroline R.; Nowak, Roberta B.; Kim, Nancy E.; Littlefield, Ryan S.; Lieber, Richard L.

2010-01-01

During myofibril assembly, thin filament lengths are precisely specified to optimize skeletal muscle function. Tropomodulins (Tmods) are capping proteins that specify thin filament lengths by controlling actin dynamics at pointed ends. In this study, we use a genetic targeting approach to explore the effects of deleting Tmod1 from skeletal muscle. Myofibril assembly, skeletal muscle structure, and thin filament lengths are normal in the absence of Tmod1. Tmod4 localizes to thin filament pointed ends in Tmod1-null embryonic muscle, whereas both Tmod3 and -4 localize to pointed ends in Tmod1-null adult muscle. Substitution by Tmod3 and -4 occurs despite their weaker interactions with striated muscle tropomyosins. However, the absence of Tmod1 results in depressed isometric stress production during muscle contraction, systemic locomotor deficits, and a shift to a faster fiber type distribution. Thus, Tmod3 and -4 compensate for the absence of Tmod1 structurally but not functionally. We conclude that Tmod1 is a novel regulator of skeletal muscle physiology. PMID:20368620

Mitochondria in the Aging Muscles of Flies and Mice: New Perspectives for Old Characters

PubMed Central

2016-01-01

Sarcopenia is the loss of muscle mass accompanied by a decrease in muscle strength and resistance and is the main cause of disability among the elderly. Muscle loss begins long before there is any clear physical impact in the senior adult. Despite all this, the molecular mechanisms underlying muscle aging are far from being understood. Recent studies have identified that not only mitochondrial metabolic dysfunction but also mitochondrial dynamics and mitochondrial calcium uptake could be involved in the degeneration of skeletal muscle mass. Mitochondrial homeostasis influences muscle quality which, in turn, could play a triggering role in signaling of systemic aging. Thus, it has become apparent that mitochondrial status in muscle cells could be a driver of whole body physiology and organismal aging. In the present review, we discuss the existing evidence for the mitochondria related mechanisms underlying the appearance of muscle aging and sarcopenia in flies and mice. PMID:27630760

Mitochondria in the Aging Muscles of Flies and Mice: New Perspectives for Old Characters.

PubMed

Del Campo, Andrea; Jaimovich, Enrique; Tevy, Maria Florencia

2016-01-01

Sarcopenia is the loss of muscle mass accompanied by a decrease in muscle strength and resistance and is the main cause of disability among the elderly. Muscle loss begins long before there is any clear physical impact in the senior adult. Despite all this, the molecular mechanisms underlying muscle aging are far from being understood. Recent studies have identified that not only mitochondrial metabolic dysfunction but also mitochondrial dynamics and mitochondrial calcium uptake could be involved in the degeneration of skeletal muscle mass. Mitochondrial homeostasis influences muscle quality which, in turn, could play a triggering role in signaling of systemic aging. Thus, it has become apparent that mitochondrial status in muscle cells could be a driver of whole body physiology and organismal aging. In the present review, we discuss the existing evidence for the mitochondria related mechanisms underlying the appearance of muscle aging and sarcopenia in flies and mice.

Lowering Temperature is the Trigger for Glycogen Build-Up and Winter Fasting in Crucian Carp (Carassius carassius).

PubMed

Varis, Joonas; Haverinen, Jaakko; Vornanen, Matti

2016-02-01

Seasonal changes in physiology of vertebrate animals are triggered by environmental cues including temperature, day-length and oxygen availability. Crucian carp (Carassius carassius) tolerate prolonged anoxia in winter by using several physiological adaptations that are seasonally activated. This study examines which environmental cues are required to trigger physiological adjustments for winter dormancy in crucian carp. To this end, crucian carp were exposed to changing environmental factors under laboratory conditions: effects of declining water temperature, shortening day-length and reduced oxygen availability, separately and in different combinations, were examined on glycogen content and enzyme activities involved in feeding (alkaline phosphatase, AP) and glycogen metabolism (glycogen synthase, GyS; glycogen phosphorylase, GP). Lowering temperature induced a fall in activity of AP and a rise in glycogen content and rate of glycogen synthesis. Relative mass of the liver, and glycogen concentration of liver, muscle and brain increased with lowering temperature. Similarly activity of GyS in muscle and expression of GyS transcripts in brain were up-regulated by lowering temperature. Shortened day-length and oxygen availability had practically no effects on measured variables. We conclude that lowering temperature is the main trigger in preparation for winter anoxia in crucian carp.

Conservative chiropractic management of urinary incontinence using applied kinesiology: a retrospective case-series report

PubMed Central

Cuthbert, Scott C.; Rosner, Anthony L.

2012-01-01

Objective The purpose of this case series is to describe the chiropractic management of 21 patients with daily stress and occasional total urinary incontinence (UI). Clinical Features Twenty-one case files of patients 13 to 90 years of age with UI from a chiropractic clinic were reviewed. The patients had a 4-month to 49-year history of UI and associated muscle dysfunction and low back and/or pelvic pain. Eighteen wore an incontinence pad throughout the day and night at the time of their appointments because of unpredictable UI. Intervention and Outcome Patients were evaluated for muscle impairments in the lumbar spine, pelvis, and pelvic floor and low back and/or hip pain. Positive manual muscle test results of the pelvis, lumbar spine muscles, and pelvic floor muscles were the most common findings. Lumbosacral dysfunction was found in 13 of the cases with pain provocation tests (applied kinesiology sensorimotor challenge); in 8 cases, this sensorimotor challenge was absent. Chiropractic manipulative therapy and soft tissue treatment addressed the soft tissue and articular dysfunctions. Chiropractic manipulative therapy involved high-velocity, low-amplitude manipulation; Cox flexion distraction manipulation; and/or use of a percussion instrument for the treatment of myofascial trigger points. Urinary incontinence symptoms resolved in 10 patients, considerably improved in 7 cases, and slightly improved in 4 cases. Periodic follow-up examinations for the past 6 years, and no less than 2 years, indicate that for each participant in this case-series report, the improvements of UI remained stable. Conclusion The patients reported in this retrospective case series showed improvement in UI symptoms that persisted over time. PMID:22942842

Botulinum toxin type a injections for cervical and shoulder girdle myofascial pain using an enriched protocol design.

PubMed

Nicol, Andrea L; Wu, Irene I; Ferrante, F Michael

2014-06-01

Myofascial pain syndrome is a regional condition of muscle pain and stiffness and is classically characterized by the presence of trigger points in affected musculature. Botulinum toxin type A (BoNT-A) has been shown to have antinociceptive properties and elicit sustained muscle relaxation, thereby possibly affording even greater relief than traditional strategies. Our goal was to determine whether direct injection of BoNT-A into painful muscle groups is effective for cervical and shoulder girdle myofascial pain. An enriched protocol design was used, wherein 114 patients with cervical and shoulder girdle myofascial pain underwent injection of BoNT-A to determine their response to the drug. Fifty-four responders were then enrolled in a 12-week, randomized, double-blind, placebo-controlled trial. Pain scales and quality of life measures were assessed at baseline and at routine follow-up visits until completion of the study after 26 weeks. Injection of BoNT-A into painful muscle groups improved average visual numerical pain scores in subjects who received a second dose of BoNT-A compared to placebo (P = 0.019 [0.26, 2.78]). Subjects who received a second dose of BoNT-A had a reduced number of headaches per week (P = 0.04 [0.07, 4.55]). Brief Pain Inventory interference scores for general activity and sleep were improved (P = 0.046 [0.038, 3.700] and 0.02 [0.37, 4.33], respectively) in those who received a second dose of BoNT-A. BoNT-A injected directly into painful muscle groups improves average pain scores and certain aspects of quality of life in patients experiencing severe cervical and shoulder girdle myofascial pain.

Noradrenergic modulation of masseter muscle activity during natural rapid eye movement sleep requires glutamatergic signalling at the trigeminal motor nucleus

PubMed Central

Schwarz, Peter B; Mir, Saba; Peever, John H

2014-01-01

Noradrenergic neurotransmission in the brainstem is closely coupled to changes in muscle activity across the sleep–wake cycle, and noradrenaline is considered to be a key excitatory neuromodulator that reinforces the arousal-related stimulus on motoneurons to drive movement. However, it is unknown if α-1 noradrenoceptor activation increases motoneuron responsiveness to excitatory glutamate (AMPA) receptor-mediated inputs during natural behaviour. We studied the effects of noradrenaline on AMPA receptor-mediated motor activity at the motoneuron level in freely behaving rats, particularly during rapid eye movement (REM) sleep, a period during which both AMPA receptor-triggered muscle twitches and periods of muscle quiescence in which AMPA drive is silent are exhibited. Male rats were subjected to electromyography and electroencephalography recording to monitor sleep and waking behaviour. The implantation of a cannula into the trigeminal motor nucleus of the brainstem allowed us to perfuse noradrenergic and glutamatergic drugs by reverse microdialysis, and thus to use masseter muscle activity as an index of motoneuronal output. We found that endogenous excitation of both α-1 noradrenoceptor and AMPA receptors during waking are coupled to motor activity; however, REM sleep exhibits an absence of endogenous α-1 noradrenoceptor activity. Importantly, exogenous α-1 noradrenoceptor stimulation cannot reverse the muscle twitch suppression induced by AMPA receptor blockade and nor can it elevate muscle activity during quiet REM, a phase when endogenous AMPA receptor activity is subthreshold. We conclude that the presence of an endogenous glutamatergic drive is necessary for noradrenaline to trigger muscle activity at the level of the motoneuron in an animal behaving naturally. PMID:24860176

New insights into muscle function during pivot feeding in seahorses.

PubMed

Van Wassenbergh, Sam; Dries, Billy; Herrel, Anthony

2014-01-01

Seahorses, pipefish and their syngnathiform relatives are considered unique amongst fishes in using elastic recoil of post-cranial tendons to pivot the head extremely quickly towards small crustacean prey. It is known that pipefish activate the epaxial muscles for a considerable time before striking, at which rotations of the head and the hyoid are temporarily prevented to allow energy storage in the epaxial tendons. Here, we studied the motor control of this system in seahorses using electromyographic recordings of the epaxial muscles and the sternohyoideus-hypaxial muscles with simultaneous high-speed video recordings of prey capture. In addition we present the results from a stimulation experiment including the muscle hypothesised to be responsible for the locking and triggering of pivot feeding in seahorses (m. adductor arcus palatini). Our data confirmed that the epaxial pre-activation pattern observed previously for pipefish also occurs in seahorses. Similar to the epaxials, the sternohyoideus-hypaxial muscle complex shows prolonged anticipatory activity. Although a considerable variation in displacements of the mouth via head rotation could be observed, it could not be demonstrated that seahorses have control over strike distance. In addition, we could not identify the source of the kinematic variability in the activation patterns of the associated muscles. Finally, the stimulation experiment supported the previously hypothesized role of the m. adductor arcus palatini as the trigger in this elastic recoil system. Our results show that pre-stressing of both the head elevators and the hyoid retractors is taking place. As pre-activation of the main muscles involved in pivot feeding has now been demonstrated for both seahorses and pipefish, this is probably a generalized trait of Syngnathidae.

New Insights into Muscle Function during Pivot Feeding in Seahorses

PubMed Central

Van Wassenbergh, Sam; Dries, Billy; Herrel, Anthony

2014-01-01

Seahorses, pipefish and their syngnathiform relatives are considered unique amongst fishes in using elastic recoil of post-cranial tendons to pivot the head extremely quickly towards small crustacean prey. It is known that pipefish activate the epaxial muscles for a considerable time before striking, at which rotations of the head and the hyoid are temporarily prevented to allow energy storage in the epaxial tendons. Here, we studied the motor control of this system in seahorses using electromyographic recordings of the epaxial muscles and the sternohyoideus-hypaxial muscles with simultaneous high-speed video recordings of prey capture. In addition we present the results from a stimulation experiment including the muscle hypothesised to be responsible for the locking and triggering of pivot feeding in seahorses (m. adductor arcus palatini). Our data confirmed that the epaxial pre-activation pattern observed previously for pipefish also occurs in seahorses. Similar to the epaxials, the sternohyoideus-hypaxial muscle complex shows prolonged anticipatory activity. Although a considerable variation in displacements of the mouth via head rotation could be observed, it could not be demonstrated that seahorses have control over strike distance. In addition, we could not identify the source of the kinematic variability in the activation patterns of the associated muscles. Finally, the stimulation experiment supported the previously hypothesized role of the m. adductor arcus palatini as the trigger in this elastic recoil system. Our results show that pre-stressing of both the head elevators and the hyoid retractors is taking place. As pre-activation of the main muscles involved in pivot feeding has now been demonstrated for both seahorses and pipefish, this is probably a generalized trait of Syngnathidae. PMID:25271759

Caspase-12 ablation preserves muscle function in the mdx mouse

PubMed Central

Moorwood, Catherine; Barton, Elisabeth R.

2014-01-01

Duchenne muscular dystrophy (DMD) is a devastating muscle wasting disease caused by mutations in dystrophin. Several downstream consequences of dystrophin deficiency are triggers of endoplasmic reticulum (ER) stress, including loss of calcium homeostasis, hypoxia and oxidative stress. During ER stress, misfolded proteins accumulate in the ER lumen and the unfolded protein response (UPR) is triggered, leading to adaptation or apoptosis. We hypothesized that ER stress is heightened in dystrophic muscles and contributes to the pathology of DMD. We observed increases in the ER stress markers BiP and cleaved caspase-4 in DMD patient biopsies, compared with controls, and an increase in multiple UPR pathways in muscles of the dystrophin-deficient mdx mouse. We then crossed mdx mice with mice null for caspase-12, the murine equivalent of human caspase-4, which are resistant to ER stress. We found that deleting caspase-12 preserved mdx muscle function, resulting in a 75% recovery of both specific force generation and resistance to eccentric contractions. The compensatory hypertrophy normally found in mdx muscles was normalized in the absence of caspase-12; this was found to be due to decreased fibre sizes, and not to a fibre type shift or a decrease in fibrosis. Fibre central nucleation was not significantly altered in the absence of caspase-12, but muscle fibre degeneration found in the mdx mouse was reduced almost to wild-type levels. In conclusion, we have identified heightened ER stress and abnormal UPR signalling as novel contributors to the dystrophic phenotype. Caspase-4 is therefore a potential therapeutic target for DMD. PMID:24879640

JSA guideline for the management of malignant hyperthermia crisis 2016.

PubMed

2017-04-01

Malignant hyperthermia (MH) can be fatal if the crisis is not appropriately treated. It is an inherited disease usually triggered by the administration of volatile inhalational anesthetics and/or succinylcholine, a muscle relaxant. In a patient with suspected MH, the mechanism of calcium release from storage in the sarcoplasmic reticulum in the skeletal muscle is abnormally accelerated. Unexplained hypercarbia representing >55 mmHg of end-tidal carbon dioxide, tachycardia, and muscle rigidity (including masseter muscle rigidity) are early signs of the initiation of MH, because the metabolism is accelerated. The body temperature can rise by >0.5 °C/15 min and may reach ≥40 °C. Respiratory and metabolic acidosis, arrhythmia, cola-colored urine, increased levels of serum potassium, and tented T-waves on electrocardiogram are common and can lead to cardiac arrest. MH should be treated by discontinuation of the triggering agents, administration of intravenous dantrolene (initially 1 mg/kg), and reduction of the body temperature. Early diagnosis and sufficient dantrolene with body temperature reduction are essential to relieve the patient's MH crisis. This guideline in Japanese translation has been posted on the website: http://www.anesth.or.jp/guide/pdf/guideline_akuseikounetsu.pdf .

Experiment K-6-07. Metabolic and morphologic properties of muscle fibers after spaceflight

NASA Technical Reports Server (NTRS)

Edgerton, R.; Miu, B.; Martin, Thomas P.; Roy, R.; Marini, J.; Leger, J. J.; Oganov, V.; Ilyina-Kakueva, E.

1990-01-01

The present study demonstrates that the general capability of skeletal muscle to maintain its proteins decreases rapidly in response to space flight. The present findings suggest further that the magnitude of enzymatic and cell volumes changes in response to space flight depend on several factors including the muscle and its fiber type composition. It appears that in order to associate physiological relevance to the observed enzymatic changes, cell volume should be considered also. Although it remains unclear as to the stimulus, or lack of stimulus, that triggers the rapid changes in muscle proteins in response to space flight, ground-based models of muscle atrophy suggest that the reduction in mechanical loading of muscle may be more important than the total amount of activation over a 24-hr period.

Effect of low-power gallium-aluminum-arsenium noncoherent light (640 nm) on muscle activity: a clinical study.

PubMed

Kelencz, Carlos A; Muñoz, Ingrid S S; Amorim, César F; Nicolau, Renata A

2010-10-01

Studies have shown the significant effects of electromagnetic irradiation in the visible region, with laser as an irradiation source. However, the effect of LEDs (light-emitting diodes) irradiation in similar wavelengths is not known. The purpose of this clinical study was to verify the effects of the LED (640 nm with 40 nm full bandwidth at half maximum) on muscle activity. The study was done with 30 test subjects, of both genders, aged 23 ± 3 years, with a mean weight of 60 kg, divided into three groups (n = 10). Fatigue was induced through the maximum power of a bite, for 60 s in two overlaid occlusal platforms, coupled to a load cell and to a biologic signal-acquisition device. LED irradiation of the right masseter muscle was applied to all subjects. The left muscle received placebo treatment. Irradiation was applied in eight points on the right masseter muscle (transcutaneous), 1.044 J per point, 2.088 J per point, or 3.132 J per point, 0.116 W, 0.522 cm(2) spot size, 0.816 cm spot Ø, continuous wave, perpendicular to the skin. An increase in muscle activity was observed after irradiation with 1.044 J per point (p < 0.05). A significant increase (p < 0.01) in the time before fatigue was observed in the irradiated muscle with 2.088 J per point, without a change in the force of contraction (p > 0.05). This change was not observed with 1.044 J per point and 3.132 J per point. The results suggest a dose-dependent relation with this kind of noncoherent irradiation in the red region of the electromagnetic spectrum in the muscle-fatigue process. It was concluded that LED can be used as a clinical tool to increase muscle activity (1.044 J per point) and to prevent fatigue (2.088 J per point), without change in the muscle force.

COMPARISON OF DRY NEEDLING VS. SHAM ON THE PERFORMANCE OF VERTICAL JUMP.

PubMed

Bandy, William D; Nelson, Russell; Beamer, Lisa

2017-10-01

Dry needling has been reported to decrease pain in subjects having myofascial trigger points, as well as pain in muscle and connective tissue. The purpose of the study was to compare the effects on the ability to perform a two-legged vertical jump between a group who received one bout of dry needling and a group who received one bout of a sham treatment. Thirty-five healthy students (19 males, 16 females) were recruited to participate in this study (mean age 22.7+/- 2.4 years). The subjects were randomly divided into two groups- dry needling (n=18) vs sham (n=17). The dry needling group received needling to four sites on bilateral gastrocnemius muscles; two at the medial head and two at the lateral head. The sham group had the four areas of the gastrocnemius muscle pressed with the tube housing the needle, but the needle was never inserted into the skin. Two-legged vertical jump was measured with chalk marks on the wall before and after the dry needling and sham treatments. Analysis with a t-test indicated that the dry needling group significantly increased vertical jump height 1.2 inches over the sham group. One bout of dry needling showed an immediate effect at significantly increasing vertical jump height in healthy, young adults. Future research is needed to determine if dry needling has any long-term effects. 2b.

Comparing Trigger Point Dry Needling and Manual Pressure Technique for the Management of Myofascial Neck/Shoulder Pain: A Randomized Clinical Trial.

PubMed

De Meulemeester, Kayleigh E; Castelein, Birgit; Coppieters, Iris; Barbe, Tom; Cools, Ann; Cagnie, Barbara

2017-01-01

The aim of this study was to investigate short-term and long-term treatment effects of dry needling (DN) and manual pressure (MP) technique with the primary goal of determining if DN has better effects on disability, pain, and muscle characteristics in treating myofascial neck/shoulder pain in women. In this randomized clinical trial, 42 female office workers with myofascial neck/shoulder pain were randomly allocated to either a DN or MP group and received 4 treatments. They were evaluated with the Neck Disability Index, general numeric rating scale, pressure pain threshold, and muscle characteristics before and after treatment. For each outcome parameter, a linear mixed-model analysis was applied to reveal group-by-time interaction effects or main effects for the factor "time." No significant differences were found between DN and MP. In both groups, significant improvement in the Neck Disability Index was observed after 4 treatments and 3 months (P < .001); the general numerical rating scale also significantly decreased after 3 months. After the 4-week treatment program, there was a significant improvement in pain pressure threshold, muscle elasticity, and stiffness. Both treatment techniques lead to short-term and long-term treatment effects. Dry needling was found to be no more effective than MP in the treatment of myofascial neck/shoulder pain. Copyright © 2016. Published by Elsevier Inc.

Length oscillation induces force potentiation in infant guinea pig airway smooth muscle.

PubMed

Wang, Lu; Chitano, Pasquale; Murphy, Thomas M

2005-12-01

Deep inspiration counteracts bronchospasm in normal subjects but triggers further bronchoconstriction in hyperresponsive airways. Although the exact mechanisms for this contrary response by normal and hyperresponsive airways are unclear, it has been suggested that the phenomenon is related to changes in force-generating ability of airway smooth muscle after mechanical oscillation. It is known that healthy immature airways of both humans and animals exhibit hyperresponsiveness. We hypothesize that the profile of active force generation after mechanical oscillation changes with maturation and that this change contributes to the expression of airway hyperresponsiveness in juveniles. We examined the effect of an acute sinusoidal length oscillation on the force-generating ability of tracheal smooth muscle from 1 wk, 3 wk, and 2- to 3-mo-old guinea pigs. We found that the length oscillation produced 15-20% initial reduction in active force equally in all age groups. This was followed by a force recovery profile that displayed striking maturation-specific features. Unique to tracheal strips from 1-wk-old animals, active force potentiated beyond the maximal force generated before oscillation. We also found that actin polymerization was required in force recovery and that prostanoids contributed to the maturation-specific force potentiation in immature airway smooth muscle. Our results suggest a potentiated mechanosensitive contractile property of hyperresponsive airway smooth muscle. This can account for further bronchoconstriction triggered by deep inspiration in hyperresponsive airways.

Optical Cross-Sectional Muscle Area Determination of Drosophila Melanogaster Adult Indirect Flight Muscles.

PubMed

Selma-Soriano, Estela; Artero, Rubén; Llamusi, Beatriz

2018-03-31

Muscle mass wasting, known as muscle atrophy, is a common phenotype in Drosophila models of neuromuscular diseases. We have used the indirect flight muscles (IFMs) of flies, specifically the dorso-longitudinal muscles (DLM), as the experimental subject to measure the atrophic phenotype brought about by different genetic causes. In this protocol, we describe how to embed fly thorax muscles for semi thin sectioning, how to obtain a good contrast between muscle and the surrounding tissue, and how to process optical microscope images for semiautomatic acquisition of quantifiable data and analysis. We describe three specific applications of the methodological pipeline. First, we show how the method can be applied to quantify muscle degeneration in a myotonic dystrophy fly model; second, measurement of muscle cross-sectional area can help to identify genes that either promote or prevent muscle atrophy and/or muscle degeneration; third, this protocol can be applied to determine whether a candidate compound is able to significantly modify a given atrophic phenotype induced by a disease-causing mutation or by an environmental trigger.

[Manual trigger point therapy of shoulder pain : Randomized controlled study of effectiveness].

PubMed

Sohns, S; Schnieder, K; Licht, G; von Piekartz, H

2016-12-01

Although chronic shoulder pain is highly prevalent and myofascial trigger points (mTrP) are thought to be found in the majority of patients with shoulder complaints, the influence on the pain mechanism remains unclear. There are only very few controlled clinical studies on the effects of manual trigger point compression therapy. This randomized controlled trial (RCT) compared the short-term effects of manual trigger point compression therapy (n = 6) with manual sham therapy (n = 6) in patients with unilateral shoulder pain due to myofascial syndrome (MFS). The measurement data were collected before and after two sessions of therapy. Pressure pain thresholds (PPT) of mTrP and symmetrically located points on the asymptomatic side were measured together with neutral points in order to detect a potential unilateral or generalized hyperalgesia. Additionally, the pain was assessed on a visual analog scale (VAS) at rest and during movement and the neck disability index (NDI) and disabilities of the arm, shoulder and hand (DASH) questionnaires were also completed and evaluated. Both treatment modalities led to a significant improvement; however, the manual trigger point compression therapy was significantly more effective in comparison to sham therapy, as measured by different parameters. The significant improvement of PPT values in the interventional group even at sites that were not directly treated, indicates central mechanisms in pain threshold modulation induced by manual compression therapy. The weaker but still measurable effects of sham therapy might be explained by the sham modality being a hands on technique or by sufficient stimulation of the trigger point region during the diagnostics and PPT measurements.

Corticospinal control of antagonistic muscles in the cat.

PubMed

Ethier, Christian; Brizzi, Laurent; Giguère, Dominic; Capaday, Charles

2007-09-01

We recently suggested that movement-related inter-joint muscle synergies are recruited by selected excitation and selected release from inhibition of cortical points. Here we asked whether a similar cortical mechanism operates in the functional linking of antagonistic muscles. To this end experiments were done on ketamine-anesthetized cats. Intracortical microstimulation (ICMS) and intramuscular electromyographic recordings were used to find and characterize wrist, elbow and shoulder antagonistic motor cortical points. Simultaneous ICMS applied at two cortical points, each evoking activity in one of a pair of antagonistic muscles, produced co-contraction of antagonistic muscle pairs. However, we found an obvious asymmetry in the strength of reciprocal inhibition; it was always significantly stronger on physiological extensors than flexors. Following intravenous injection of a single bolus of strychnine, a cortical point at which only a physiological flexor was previously activated also elicited simultaneous activation of its antagonist. This demonstrates that antagonistic corticospinal neurons are closely grouped, or intermingled. To test whether releasing a cortical point from inhibition allows it to be functionally linked with an antagonistic cortical point, one of three GABA(A) receptor antagonists, bicuculline, gabazine or picrotoxin, was injected iontophoretically at one cortical point while stimulation was applied to an antagonistic cortical point. This coupling always resulted in co-contraction of the represented antagonistic muscles. Thus, antagonistic motor cortical points are linked by excitatory intracortical connections held in check by local GABAergic inhibition, with reciprocal inhibition occurring at the spinal level. Importantly, the asymmetry of cortically mediated reciprocal inhibition would appear significantly to bias muscle maps obtained by ICMS in favor of physiological flexors.

Muscle development and obesity

PubMed Central

2008-01-01

The formation of skeletal muscle from the epithelial somites involves a series of events triggered by temporally and spatially discrete signals resulting in the generation of muscle fibers which vary in their contractile and metabolic nature. The fiber type composition of muscles varies between individuals and it has now been found that there are differences in fiber type proportions between lean and obese animals and humans. Amongst the possible causes of obesity, it has been suggested that inappropriate prenatal environments may ‘program’ the fetus and may lead to increased risks for disease in adult life. The characteristics of muscle are both heritable and plastic, giving the tissue some ability to adapt to signals and stimuli both pre and postnatally. Given that muscle is a site of fatty acid oxidation and carbohydrate metabolism and that its development can be changed by prenatal events, it is interesting to examine the possible relationship between muscle development and the risk of obesity. PMID:19279728

Unilateral Renal Ischemia as a Model of Acute Kidney Injury and Renal Fibrosis in Cats.

PubMed

Schmiedt, C W; Brainard, B M; Hinson, W; Brown, S A; Brown, C A

2016-01-01

The objectives of this study were to define the acute and chronic effects of 1-hour unilateral in vivo renal ischemia on renal function and histology in cats. Twenty-one adult purpose-bred research cats were anesthetized, and 1 kidney underwent renal artery and vein occlusion for 1 hour. Serum creatinine and urea concentrations, urine protein:creatinine ratio, urine-specific gravity, glomerular filtration rate, hematocrit, platelet concentration and function, and white blood cell count were measured at baseline and variable time points after ischemia. Renal histopathology was evaluated on days 3, 6, 12, 21, 42, and 70 postischemia; changes in smooth muscle actin and interstitial collagen were examined. Following ischemia, whole animal glomerular filtration rate was significantly reduced (57% of baseline on day 6; P < .05). At the early time points, the ischemic kidneys exhibited severe acute epithelial necrosis accompanied by evidence of regeneration of tubules predominantly within the corticomedullary junction. At later periods, postischemic kidneys had evidence of tubular atrophy and interstitial inflammation with significantly more smooth muscle actin and interstitial collagen staining and interstitial fibrosis when compared with the contralateral control kidneys. This study characterizes the course of ischemic acute kidney injury in cats and demonstrates that ischemic acute kidney injury triggers chronic fibrosis, interstitial inflammation, and tubular atrophy in feline kidneys. These late changes are typical of those observed in cats with naturally occurring chronic kidney disease. © The Author(s) 2015.

Ensemble of shape functions and support vector machines for the estimation of discrete arm muscle activation from external biceps 3D point clouds.

PubMed

Abraham, Leandro; Bromberg, Facundo; Forradellas, Raymundo

2018-04-01

Muscle activation level is currently being captured using impractical and expensive devices which make their use in telemedicine settings extremely difficult. To address this issue, a prototype is presented of a non-invasive, easy-to-install system for the estimation of a discrete level of muscle activation of the biceps muscle from 3D point clouds captured with RGB-D cameras. A methodology is proposed that uses the ensemble of shape functions point cloud descriptor for the geometric characterization of 3D point clouds, together with support vector machines to learn a classifier that, based on this geometric characterization for some points of view of the biceps, provides a model for the estimation of muscle activation for all neighboring points of view. This results in a classifier that is robust to small perturbations in the point of view of the capturing device, greatly simplifying the installation process for end-users. In the discrimination of five levels of effort with values up to the maximum voluntary contraction (MVC) of the biceps muscle (3800 g), the best variant of the proposed methodology achieved mean absolute errors of about 9.21% MVC - an acceptable performance for telemedicine settings where the electric measurement of muscle activation is impractical. The results prove that the correlations between the external geometry of the arm and biceps muscle activation are strong enough to consider computer vision and supervised learning an alternative with great potential for practical applications in tele-physiotherapy. Copyright © 2018 Elsevier Ltd. All rights reserved.

Vasoactive intestinal peptide test

MedlinePlus

... found in cells in the nervous system and gut. VIP has many functions, including relaxing certain muscles, triggering release of hormones from the pancreas, gut, and hypothalamus, and increasing the amount of water ...

Quantification of birefringence readily measures the level of muscle damage in zebrafish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berger, Joachim, E-mail: Joachim.Berger@Monash.edu; Sztal, Tamar; Currie, Peter D.

2012-07-13

Highlights: Black-Right-Pointing-Pointer Report of an unbiased quantification of the birefringence of muscle of fish larvae. Black-Right-Pointing-Pointer Quantification method readily identifies level of overall muscle damage. Black-Right-Pointing-Pointer Compare zebrafish muscle mutants for level of phenotype severity. Black-Right-Pointing-Pointer Proposed tool to survey treatments that aim to ameliorate muscular dystrophy. -- Abstract: Muscular dystrophies are a group of genetic disorders that progressively weaken and degenerate muscle. Many zebrafish models for human muscular dystrophies have been generated and analysed, including dystrophin-deficient zebrafish mutants dmd that model Duchenne Muscular Dystrophy. Under polarised light the zebrafish muscle can be detected as a bright area in anmore » otherwise dark background. This light effect, called birefringence, results from the diffraction of polarised light through the pseudo-crystalline array of the muscle sarcomeres. Muscle damage, as seen in zebrafish models for muscular dystrophies, can readily be detected by a reduction in the birefringence. Therefore, birefringence is a very sensitive indicator of overall muscle integrity within larval zebrafish. Unbiased documentation of the birefringence followed by densitometric measurement enables the quantification of the birefringence of zebrafish larvae. Thereby, the overall level of muscle integrity can be detected, allowing the identification and categorisation of zebrafish muscle mutants. In addition, we propose that the establish protocol can be used to analyse treatments aimed at ameliorating dystrophic zebrafish models.« less

Compensatable muon collider calorimeter with manageable backgrounds

DOEpatents

Raja, Rajendran

2015-02-17

A method and system for reducing background noise in a particle collider, comprises identifying an interaction point among a plurality of particles within a particle collider associated with a detector element, defining a trigger start time for each of the pixels as the time taken for light to travel from the interaction point to the pixel and a trigger stop time as a selected time after the trigger start time, and collecting only detections that occur between the start trigger time and the stop trigger time in order to thereafter compensate the result from the particle collider to reduce unwanted background detection.

[Study on origin of meridians and collaterals through pain relieving effect of muscle regions].

PubMed

Dong, Bao-Qiang; Li, Chun-Ri; Huang, Feng-Yun; Zhang, Shu-Jian; Xue, Li-Gong

2011-08-01

Through analysis on sequencing of meridians and their muscle regions, their pertaining organs, run ning courses, linking and indications described in Zubi Shiyimai (Eleven Meridian of Foot and Hand), Yinyang Shiyimai (Eleven Meridian of Yinyang), Lingshu: Jingmai (Miraculous Pivot: Meridian) and Lingshu: Jinjing (Miraculous Pivot: Muscle Meridian), it is found that most of the indications of acupuncture in ancient time are symptoms of the muscle regions. 62.59% points of the national standard acupoints location close to tender points of the muscle regions, which indicates that the origin of early acupoints are tender points along the running courses of the muscle regions. Thus, it is concluded that meridians and their muscle regions have the same origin, which provides new train of thinking for a better comprehension of origin of meridians and collaterals.

Position sense at the human elbow joint measured by arm matching or pointing.

PubMed

Tsay, Anthony; Allen, Trevor J; Proske, Uwe

2016-10-01

Position sense at the human elbow joint has traditionally been measured in blindfolded subjects using a forearm matching task. Here we compare position errors in a matching task with errors generated when the subject uses a pointer to indicate the position of a hidden arm. Evidence from muscle vibration during forearm matching supports a role for muscle spindles in position sense. We have recently shown using vibration, as well as muscle conditioning, which takes advantage of muscle's thixotropic property, that position errors generated in a forearm pointing task were not consistent with a role by muscle spindles. In the present study we have used a form of muscle conditioning, where elbow muscles are co-contracted at the test angle, to further explore differences in position sense measured by matching and pointing. For fourteen subjects, in a matching task where the reference arm had elbow flexor and extensor muscles contracted at the test angle and the indicator arm had its flexors conditioned at 90°, matching errors lay in the direction of flexion by 6.2°. After the same conditioning of the reference arm and extension conditioning of the indicator at 0°, matching errors lay in the direction of extension (5.7°). These errors were consistent with predictions based on a role by muscle spindles in determining forearm matching outcomes. In the pointing task subjects moved a pointer to align it with the perceived position of the hidden arm. After conditioning of the reference arm as before, pointing errors all lay in a more extended direction than the actual position of the arm by 2.9°-7.3°, a distribution not consistent with a role by muscle spindles. We propose that in pointing muscle spindles do not play the major role in signalling limb position that they do in matching, but that other sources of sensory input should be given consideration, including afferents from skin and joint.

Ex vivo bupivacaine treatment results in increased adipogenesis of skeletal muscle cells in the rat.

PubMed

Yamanouchi, Keitaro; Nakamura, Katsuyuki; Takegahara, Yuki; Nakano, Shin-ichi; Nishihara, Masugi

2013-11-01

Intramuscular adipose tissue (IMAT) is observed in some skeletal muscle pathologies. IMAT is implicated not only in the disorders of muscle contraction, but also of metabolism and insulin sensitivity due to its nature as a secretary organ. Several studies indicate the presence of cells with adipogenic potential in skeletal muscle. However, the mechanism of fate specification that triggers these cells to enter an adipogenic program in vivo remains to be solved. In the present study, we examined whether activation of the adipogenic program of muscle-resident cells precedes their proliferation upon muscle injury. For this purpose, muscle injury was induced by injecting bupivacaine (BPVC) to excised skeletal muscle ex vivo. Cells isolated from ex vivo BPVC-treated muscle exhibited higher adipogenic potential than those from saline-treated muscle. Pre-plating exposure of skeletal muscle cells to basic fibroblast growth factor (bFGF) mimicked the effect of ex vivo BPVC-treatment, suggesting that bFGF released from extracellular matrix in response to muscle injury activates their adipogenic program. Interestingly, the number of myotubes were significantly reduced in the culture from BPVC-treated muscle, suggesting that adipocytes negatively regulate myogenesis. © 2013 Japanese Society of Animal Science.

A rare case of recurrent vasodepressive attacks of 2-hours duration: analysis of the mechanism by muscle sympathetic nerve activity recording.

PubMed

Yatomi, A; Iguchi, A; Uemura, K; Sakamoto, N; Iwase, S; Mano, T

1989-03-01

Muscle sympathetic nerve activity was recorded in a 57-year-old male patient suffering from severe hypotensive attacks with bradycardia for 10 years. Continuous blood pressure recording demonstrated frequent drastic falls in pressure. Disappearance and reappearance of muscle sympathetic nerve activity coincided with the onset and termination of attacks. Awakening from sleep or emotional and/or cardiovascular stress seems to trigger hypotension. Cardiac pacemaker was not useful in limiting the attack, because right ventricular pacing caused abrupt falls in both blood pressure and heart rate.

Review of the Diagnosis and Treatment of Periodic Paralysis

PubMed Central

Fontaine, Bertrand; Hanna, Michael G.; Johnson, Nicholas E.; Kissel, John T.; Sansone, Valeria A.; Shieh, Perry B.; Tawil, Rabi N.; Trivedi, Jaya; Cannon, Stephen C.; Griggs, Robert C.

2017-01-01

ABSTRACT Periodic paralyses (PPs) are rare neuromuscular disorders caused by mutations in skeletal muscle sodium, calcium, and potassium channel genes. PPs include hypokalemic paralysis, hyperkalemic paralysis, and Andersen‐Tawil syndrome. Common features of PP include autosomal dominant inheritance, onset typically in the first or second decades, episodic attacks of flaccid weakness, which are often triggered by diet or rest after exercise. Diagnosis is based on the characteristic clinic presentation then confirmed by genetic testing. In the absence of an identified genetic mutation, documented low or high potassium levels during attacks or a decrement on long exercise testing support diagnosis. The treatment approach should include both management of acute attacks and prevention of attacks. Treatments include behavioral interventions directed at avoidance of triggers, modification of potassium levels, diuretics, and carbonic anhydrase inhibitors. Muscle Nerve 57: 522–530, 2018 PMID:29125635

A New Perspective of Neuromyopathy to Explain Intractable Pancreatic Cancer Pains; Dry Needling as an Effective Adjunct to Neurolytic Blocks

PubMed Central

Vas, Lakshmi; Phanse, Sushama; Pai, Renuka

2016-01-01

We present a new perspective of neuromyopathy in pancreatic cancer pain (PCP) referral to bodywall; proposal of new rationale to include ultrasound guided dry needling (USGDN) of body wall muscles as an effective adjunct to neurolytic coeliac plexus block (NCPB) or splanchnic nerve radiofrequency ablation (SRF) for comprehensive interventional management. Methods: PCP response to SRF in 2 patients and NCPB in 3 patients was documented on numerical rating scale (NRS) on post procedure days 3 and 15. If the residual pain was >5 NRS on day 15, USGDN of abdominal and back muscles was started on a thrice weekly basis. The response to USGDN documented on day 30 after approximately 6 sessions of DN, showed a significant pain reduction (0-2 NRS) with 50% reduction of pre-treatment opioid consumption. This was sustained at 6 months or till their demise. Convergence of visceral and somatic nerves at the dorsal horn (viscerosomatic neurons) causes referral of visceral pain to the back and abdominal muscles. This leads to formation of myofascial trigger points (MTrPs) in the muscles which sets up a parallel network of sensitized peripheral and central motor nociceptive processing (neuromyopathy). USGDN specifically addressed the MTrPs that develop as an epiphenomenon of self-perpetuating neuromyopathy while SRF/NCPB, analgesics and neuromodulators could address only visceral nociceptive afferents (pain mediated through celiac plexus) which forms a meagre 10% of the total spinal cord afferent input. Thus, we conclude that combination of neuromyopathy and viscerosomatic convergence in PCP indicate a specific role for DN as an adjunct to SRF/NCPB in our patients PMID:26962286

Magnetic stimulation of the upper trapezius muscles in patients with migraine - A pilot study.

PubMed

Sollmann, Nico; Trepte-Freisleder, Florian; Albers, Lucia; Jung, Nikolai H; Mall, Volker; Meyer, Bernhard; Heinen, Florian; Krieg, Sandro M; Landgraf, Mirjam N

2016-11-01

Repetitive peripheral magnetic stimulation (rPMS) has been applied to musculoskeletal pain conditions. Since recent data show that migraine and tension-type headache (TTH) might be closely related to peripheral muscular pain in the neck and shoulder region (supporting the concept of the trigemino-cervical complex (TCC)), this pilot study explores the acceptance of rPMS to the upper trapezius muscles in migraine (partly in combination with TTH). We used rPMS to stimulate active myofascial trigger points (aTrPs) of the upper trapezius muscles in 20 young adults suffering from migraine. Acceptance was assessed by a standardized questionnaire, whereas self-rated effectiveness was evaluated by headache calendars and the Migraine Disability Assessment (MIDAS). Algometry was performed to explore the local effect of rPMS on the muscles. Acceptance of rPMS was shown in all subjects without any adverse events, and rPMS had a statistically significant impact on almost every parameter of the headache calendar and MIDAS. Among others, the number of migraine attacks (p < 0.001) and migraine intensity (p = 0.001) significantly decreased regarding pre- and post-stimulation assessments. Accordingly, 100.0% of subjects would repeat the stimulation, while 90.0% would recommend rPMS as a treatment option for migraine. rPMS might represent a promising tool to alleviate migraine symptoms within the context of myofascial pain. This might be due to stimulation-dependent modulation of the peripheral sensory effect within the TCC in migraine. However, sham-controlled studies with larger and more homogeneous cohorts are needed to prove a potential beneficial effect. Ethics Committee Registration Numbers: 356-14 and 447/14. Copyright © 2016 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Effects of a sour bolus on the intramuscular electromyographic (EMG) activity of muscles in the submental region.

PubMed

Palmer, Phyllis M; McCulloch, Timothy M; Jaffe, Debra; Neel, Amy T

2005-01-01

A sour bolus has been used as a modality in the treatment of oropharyngeal dysphagia based on the hypothesis that this stimulus provides an effective preswallow sensory input that lowers the threshold required to trigger a pharyngeal swallow. The result is a more immediate swallow onset time. Additionally, the sour bolus may invigorate the oral muscles resulting in stronger contractions during the swallow. The purpose of this investigation was to compare the intramuscular electromyographic activity of the mylohyoid, geniohyoid, and anterior belly of the digastric muscles during sour and water boluses with regard to duration, strength, and timing of muscle activation. Muscle duration, swallow onset time, and pattern of muscle activation did not differ for the two bolus types. Muscle activation time was more tightly approximated across the onsets of the three muscles when a sour bolus was used. A sour bolus also resulted in a stronger muscle contraction as evidenced by greater electromyographic activity. These data support the use of a sour bolus as part of a treatment paradigm.

Influence of cigarette smoking on human autonomic function

NASA Technical Reports Server (NTRS)

Niedermaier, O. N.; Smith, M. L.; Beightol, L. A.; Zukowska-Grojec, Z.; Goldstein, D. S.; Eckberg, D. L.

1993-01-01

BACKGROUND. Although cigarette smoking is known to lead to widespread augmentation of sympathetic nervous system activity, little is known about the effects of smoking on directly measured human sympathetic activity and its reflex control. METHODS AND RESULTS. We studied the acute effects of smoking two research-grade cigarettes on muscle sympathetic nerve activity and on arterial baroreflex-mediated changes of sympathetic and vagal neural cardiovascular outflows in eight healthy habitual smokers. Measurements were made during frequency-controlled breathing, graded Valsalva maneuvers, and carotid baroreceptor stimulation with ramped sequences of neck pressure and suction. Smoking provoked the following changes: Arterial pressure increased significantly, and RR intervals, RR interval spectral power at the respiratory frequency, and muscle sympathetic nerve activity decreased. Plasma nicotine levels increased significantly, but plasma epinephrine, norepinephrine, and neuropeptide Y levels did not change. Peak sympathetic nerve activity during and systolic pressure overshoots after Valsalva straining increased significantly in proportion to increases of plasma nicotine levels. The average carotid baroreceptor-cardiac reflex relation shifted rightward and downward on arterial pressure and RR interval axes; average gain, operational point, and response range did not change. CONCLUSIONS. In habitual smokers, smoking acutely reduces baseline levels of vagal-cardiac nerve activity and completely resets vagally mediated arterial baroreceptor-cardiac reflex responses. Smoking also reduces muscle sympathetic nerve activity but augments increases of sympathetic activity triggered by brief arterial pressure reductions. This pattern of autonomic changes is likely to influence smokers' responses to acute arterial pressure reductions importantly.

Quantitative Ultrasound Using Texture Analysis of Myofascial Pain Syndrome in the Trapezius.

PubMed

Kumbhare, Dinesh A; Ahmed, Sara; Behr, Michael G; Noseworthy, Michael D

2018-01-01

Objective-The objective of this study is to assess the discriminative ability of textural analyses to assist in the differentiation of the myofascial trigger point (MTrP) region from normal regions of skeletal muscle. Also, to measure the ability to reliably differentiate between three clinically relevant groups: healthy asymptomatic, latent MTrPs, and active MTrP. Methods-18 and 19 patients were identified with having active and latent MTrPs in the trapezius muscle, respectively. We included 24 healthy volunteers. Images were obtained by research personnel, who were blinded with respect to the clinical status of the study participant. Histograms provided first-order parameters associated with image grayscale. Haralick, Galloway, and histogram-related features were used in texture analysis. Blob analysis was conducted on the regions of interest (ROIs). Principal component analysis (PCA) was performed followed by multivariate analysis of variance (MANOVA) to determine the statistical significance of the features. Results-92 texture features were analyzed for factorability using Bartlett's test of sphericity, which was significant. The Kaiser-Meyer-Olkin measure of sampling adequacy was 0.94. PCA demonstrated rotated eigenvalues of the first eight components (each comprised of multiple texture features) explained 94.92% of the cumulative variance in the ultrasound image characteristics. The 24 features identified by PCA were included in the MANOVA as dependent variables, and the presence of a latent or active MTrP or healthy muscle were independent variables. Conclusion-Texture analysis techniques can discriminate between the three clinically relevant groups.

The effects of aerobic exercise and strengthening exercise on pain pressure thresholds.

PubMed

Lee, Han Suk

2014-07-01

[Purpose] We assessed the effects of aerobic exercise and strengthening exercise on pain pressure thresholds (PPTs) over time. [Subjects and Methods] Fifteen healthy participants were recruited and randomly divided into 3 groups: aerobic exercise, strengthening exercise, and control. The subjects in the aerobic group walked on a treadmill for 40 min at 6.5 km/h. The subjects in the strength group performed circuit training that included bench press, lat pull down, biceps curl, triceps extension, and shoulder press based on the perceived exertion for 40 min. The subjects in the control group rested without any exercise in a quiet room for 40 min. The PPTs of 5 potential muscle trigger points before exercise, and immediately after 10 and 40 min of exercise or rest were measured using an electronic algometer (JTECH Medical, USA). The Friedman's, Kruskal-Wallis, and Mann-Whitney tests were performed using SPSS 18.0 (IBM, Korea). [Results] The PPTs of all subjects decreased after 10 min of exercise, but the difference was not statistically significant. The PPTs of the control group decreased after 40 min. Furthermore, the PPTs of 3 muscles increased after 40 min of aerobic exercise and of 6 muscles after 40 min of strengthening exercise. No significant difference in PPTs was noted among the groups. [Conclusion] The results show that 40 min is a more appropriate exercise time, although the efficacy of controlling pain did not differ between strengthening exercise and aerobic exercise.

COMPARISON OF DRY NEEDLING VS. SHAM ON THE PERFORMANCE OF VERTICAL JUMP

PubMed Central

Nelson, Russell; Beamer, Lisa

2017-01-01

Introduction Dry needling has been reported to decrease pain in subjects having myofascial trigger points, as well as pain in muscle and connective tissue. Objective The purpose of the study was to compare the effects on the ability to perform a two-legged vertical jump between a group who received one bout of dry needling and a group who received one bout of a sham treatment. Methods Thirty-five healthy students (19 males, 16 females) were recruited to participate in this study (mean age 22.7+/- 2.4 years). The subjects were randomly divided into two groups- dry needling (n=18) vs sham (n=17). The dry needling group received needling to four sites on bilateral gastrocnemius muscles; two at the medial head and two at the lateral head. The sham group had the four areas of the gastrocnemius muscle pressed with the tube housing the needle, but the needle was never inserted into the skin. Two-legged vertical jump was measured with chalk marks on the wall before and after the dry needling and sham treatments. Results Analysis with a t-test indicated that the dry needling group significantly increased vertical jump height 1.2 inches over the sham group. Conclusion One bout of dry needling showed an immediate effect at significantly increasing vertical jump height in healthy, young adults. Future research is needed to determine if dry needling has any long-term effects. Level of Evidence 2b PMID:29181252

Verification of an optimized stimulation point on the abdominal wall for transcutaneous neuromuscular electrical stimulation for activation of deep lumbar stabilizing muscles.

PubMed

Baek, Seung Ok; Cho, Hee Kyung; Jung, Gil Su; Son, Su Min; Cho, Yun Woo; Ahn, Sang Ho

2014-09-01

Transcutaneous neuromuscular electrical stimulation (NMES) can stimulate contractions in deep lumbar stabilizing muscles. An optimal protocol has not been devised for the activation of these muscles by NMES, and information is lacking regarding an optimal stimulation point on the abdominal wall. The goal was to determine a single optimized stimulation point on the abdominal wall for transcutaneous NMES for the activation of deep lumbar stabilizing muscles. Ultrasound images of the spinal stabilizing muscles were captured during NMES at three sites on the lateral abdominal wall. After an optimal location for the placement of the electrodes was determined, changes in the thickness of the lumbar multifidus (LM) were measured during NMES. Three stimulation points were investigated using 20 healthy physically active male volunteers. A reference point R, 1 cm superior to the iliac crest along the midaxillary line, was used. Three study points were used: stimulation point S1 was located 2 cm superior and 2 cm medial to the anterior superior iliac spine, stimulation point S3 was 2 cm below the lowest rib along the same sagittal plane as S1, and stimulation point S2 was midway between S1 and S3. Sessions were conducted stimulating at S1, S2, or S3 using R for reference. Real-time ultrasound imaging (RUSI) of the abdominal muscles was captured during each stimulation session. In addition, RUSI images were captured of the LM during stimulation at S1. Thickness, as measured by RUSI, of the transverse abdominis (TrA), obliquus internus, and obliquus externus was greater during NMES than at rest for all three study points (p<.05). Transverse abdominis was significantly stimulated more by NMES at S1 than at the other points (p<.05). The LM thickness was also significantly greater during NMES at S1 than at rest (p<.05). Neuromuscular electrical stimulation at S1 optimally activated deep spinal stabilizing muscles, TrA and LM, as evidenced by RUSI. The authors recommend this optimal stimulation point be used for NMES in the course of lumbar spine stabilization training in patients having difficulty initiating contraction of these muscles. Copyright © 2014 Elsevier Inc. All rights reserved.

Over the Counter Laxatives for Constipation: Use with Caution

MedlinePlus

... bowel movements Electrolyte imbalance with prolonged use Oral stimulants (Dulcolax, Senokot) Trigger rhythmic contractions of intestinal muscles ... combine different types of laxatives, such as a stimulant and a stool softener. But combination products don' ...

Morphological changes in hind limb muscles elicited by adjuvant-induced arthritis of the rat knee.

PubMed

Ozawa, J; Kurose, T; Kawamata, S; Yamaoka, K

2010-02-01

We investigated qualitative and quantitative changes in rat hind limb muscles caused by complete Freund's adjuvant (CFA)-induced knee joint pain. One week after CFA injection, muscle atrophy was induced only on the CFA-injected side. Wet weight of the rectus femoris (RF) and soleus (SOL) muscles were significantly decreased by 20% and 19%, respectively. The reduction in cross-sectional areas by CFA was similar for fast and slow muscle fibers in the RF (10% vs 15%, respectively) and SOL muscles (16% vs 16%, respectively). At the light microscopic level, pathological changes were not found in the RF muscles on both sides, although the infiltration of mononuclear cells and muscle regeneration were found in the SOL muscles on CFA-injected and contralateral control sides. On the other hand, electron microscopy revealed degenerative changes in the RF and SOL muscles on the CFA-injected side. Interestingly, sarcomere hypercontraction, indicating overexercise, was observed to a limited extent in the SOL muscles on the control side. In conclusions, knee joint pain can trigger the rapid development of muscle atrophy with degenerative changes not only in thigh but also calf muscles. This indicates that early interventions to inhibit joint pain or inflammation may prevent muscle atrophy.

Sepsis induces long-term metabolic and mitochondrial muscle stem cell dysfunction amenable by mesenchymal stem cell therapy

PubMed Central

Rocheteau, P.; Chatre, L.; Briand, D.; Mebarki, M.; Jouvion, G.; Bardon, J.; Crochemore, C.; Serrani, P.; Lecci, P. P.; Latil, M.; Matot, B.; Carlier, P. G.; Latronico, N.; Huchet, C.; Lafoux, A.; Sharshar, T.; Ricchetti, M.; Chrétien, F.

2015-01-01

Sepsis, or systemic inflammatory response syndrome, is the major cause of critical illness resulting in admission to intensive care units. Sepsis is caused by severe infection and is associated with mortality in 60% of cases. Morbidity due to sepsis is complicated by neuromyopathy, and patients face long-term disability due to muscle weakness, energetic dysfunction, proteolysis and muscle wasting. These processes are triggered by pro-inflammatory cytokines and metabolic imbalances and are aggravated by malnutrition and drugs. Skeletal muscle regeneration depends on stem (satellite) cells. Herein we show that mitochondrial and metabolic alterations underlie the sepsis-induced long-term impairment of satellite cells and lead to inefficient muscle regeneration. Engrafting mesenchymal stem cells improves the septic status by decreasing cytokine levels, restoring mitochondrial and metabolic function in satellite cells, and improving muscle strength. These findings indicate that sepsis affects quiescent muscle stem cells and that mesenchymal stem cells might act as a preventive therapeutic approach for sepsis-related morbidity. PMID:26666572

Sepsis induces long-term metabolic and mitochondrial muscle stem cell dysfunction amenable by mesenchymal stem cell therapy.

PubMed

Rocheteau, P; Chatre, L; Briand, D; Mebarki, M; Jouvion, G; Bardon, J; Crochemore, C; Serrani, P; Lecci, P P; Latil, M; Matot, B; Carlier, P G; Latronico, N; Huchet, C; Lafoux, A; Sharshar, T; Ricchetti, M; Chrétien, F

2015-12-15

Sepsis, or systemic inflammatory response syndrome, is the major cause of critical illness resulting in admission to intensive care units. Sepsis is caused by severe infection and is associated with mortality in 60% of cases. Morbidity due to sepsis is complicated by neuromyopathy, and patients face long-term disability due to muscle weakness, energetic dysfunction, proteolysis and muscle wasting. These processes are triggered by pro-inflammatory cytokines and metabolic imbalances and are aggravated by malnutrition and drugs. Skeletal muscle regeneration depends on stem (satellite) cells. Herein we show that mitochondrial and metabolic alterations underlie the sepsis-induced long-term impairment of satellite cells and lead to inefficient muscle regeneration. Engrafting mesenchymal stem cells improves the septic status by decreasing cytokine levels, restoring mitochondrial and metabolic function in satellite cells, and improving muscle strength. These findings indicate that sepsis affects quiescent muscle stem cells and that mesenchymal stem cells might act as a preventive therapeutic approach for sepsis-related morbidity.

[Effect of caffeine on active Ca2+ ion transport in a homogenate of skeletal muscles and myocardium].

PubMed

Ritov, V B; Murzakhmetova, M K

1985-08-01

A Ca2-selective electrode was used to study active transport of Ca2+ by sarcoplasmic reticulum fragments of rabbit skeletal muscle and myocardium homogenates. The specific Ca2+ transport activities (mumol Ca2+/min/mg tissue) are 40 = 60 and 3 = 5 units for fast and slow muscles and the myocardium, respectively. Caffeine (5 mM) exerts a powerful inhibitory influence on Ca2+ transport in skeletal muscle homogenates. For fast muscles, the degree of inhibition exceeds 50%. The rate of Ca2+ transport in the myocardium homogenate increases in the presence of creatine phosphate. The latter produces no effect on Ca2+ transport in skeletal muscle homogenates. The high sensitivity of Ca2 transport to caffeine, a specific blocker of Ca2+ transport to the terminal cisterns of the sarcoplasmic reticulum, suggests that the terminal cisterns, apart from being a reservoir for Ca2+ needed for contraction trigger, may play an essential role in muscle relaxation.

Changes in blood flow and cellular metabolism at a myofascial trigger point with trigger point release (ischemic compression): a proof-of-principle pilot study

PubMed Central

Moraska, Albert F.; Hickner, Robert C.; Kohrt, Wendy M.; Brewer, Alan

2012-01-01

Objective To demonstrate proof-of-principle measurement for physiological change within an active myofascial trigger point (MTrP) undergoing trigger point release (ischemic compression). Design Interstitial fluid was sampled continuously at a trigger point before and after intervention. Setting A biomedical research clinic at a university hospital. Participants Two subjects from a pain clinic presenting with chronic headache pain. Interventions A single microdialysis catheter was inserted into an active MTrP of the upper trapezius to allow for continuous sampling of interstitial fluid before and after application of trigger point therapy by a massage therapist. Main Outcome Measures Procedural success, pain tolerance, feasibility of intervention during sample collection, determination of physiologically relevant values for local blood flow, as well as glucose and lactate concentrations. Results Both patients tolerated the microdialysis probe insertion into the MTrP and treatment intervention without complication. Glucose and lactate concentrations were measured in the physiological range. Following intervention, a sustained increase in lactate was noted for both subjects. Conclusions Identifying physiological constituents of MTrP’s following intervention is an important step toward understanding pathophysiology and resolution of myofascial pain. The present study forwards that aim by showing proof-of-concept for collection of interstitial fluid from an MTrP before and after intervention can be accomplished using microdialysis, thus providing methodological insight toward treatment mechanism and pain resolution. Of the biomarkers measured in this study, lactate may be the most relevant for detection and treatment of abnormalities in the MTrP. PMID:22975226

Neural basis for hand muscle synergies in the primate spinal cord.

PubMed

Takei, Tomohiko; Confais, Joachim; Tomatsu, Saeka; Oya, Tomomichi; Seki, Kazuhiko

2017-08-08

Grasping is a highly complex movement that requires the coordination of multiple hand joints and muscles. Muscle synergies have been proposed to be the functional building blocks that coordinate such complex motor behaviors, but little is known about how they are implemented in the central nervous system. Here we demonstrate that premotor interneurons (PreM-INs) in the primate cervical spinal cord underlie the spatiotemporal patterns of hand muscle synergies during a voluntary grasping task. Using spike-triggered averaging of hand muscle activity, we found that the muscle fields of PreM-INs were not uniformly distributed across hand muscles but rather distributed as clusters corresponding to muscle synergies. Moreover, although individual PreM-INs have divergent activation patterns, the population activity of PreM-INs reflects the temporal activation of muscle synergies. These findings demonstrate that spinal PreM-INs underlie the muscle coordination required for voluntary hand movements in primates. Given the evolution of neural control of primate hand functions, we suggest that spinal premotor circuits provide the fundamental coordination of multiple joints and muscles upon which more fractionated control is achieved by superimposed, phylogenetically newer, pathways.

Immediate and long-term transcriptional response of hind muscle tissue to transient variation of incubation temperature in broilers.

PubMed

Naraballobh, Watcharapong; Trakooljul, Nares; Muráni, Eduard; Brunner, Ronald; Krischek, Carsten; Janisch, Sabine; Wicke, Michael; Ponsuksili, Siriluck; Wimmers, Klaus

2016-05-04

In oviparous species accidental variation of incubation temperatures may occur under natural conditions and mechanisms may have evolved by natural selection that facilitate coping with these stressors. However, under controlled artificial incubation modification of egg incubation temperature has been shown to have a wide-ranging impact on post-hatch development in several poultry species. Because developmental changes initiated in-ovo can affect poultry production, understanding the molecular routes and epigenetic alterations induced by incubation temperature differences may allow targeted modification of phenotypes. In order to identify molecular pathways responsive to variable incubation temperature, broiler eggs were incubated at a lower or higher temperature (36.8 °C, 38.8 °C) relative to control (37.8 °C) over two developmental intervals, embryonic days (E) 7-10 and 10-13. Global gene expression of M. gastrocnemius was assayed at E10, E13, and slaughter age [post-hatch day (D) 35] (6 groups; 3 time points; 8 animals each) by microarray analysis and treated samples were compared to controls within each time point. Transcript abundance differed for between 113 and 738 genes, depending on treatment group, compared to the respective control. In particular, higher incubation temperature during E7-10 immediately affected pathways involved in energy and lipid metabolism, cell signaling, and muscle development more so than did other conditions. But lower incubation temperature during E10-13 affected pathways related to cellular function and growth, and development of organ, tissue, and muscle as well as nutrient metabolism pathways at D35. Shifts in incubation temperature provoke specific immediate and long-term transcriptional responses. Further, the transcriptional response to lower incubation temperature, which did not affect the phenotypes, mediates compensatory effects reflecting adaptability. In contrast, higher incubation temperature triggers gene expression and has long-term effects on the phenotype, reflecting considerable phenotypic plasticity.

Anaesthetic injection versus ischemic compression for the pain relief of abdominal wall trigger points in women with chronic pelvic pain.

PubMed

Montenegro, Mary L L S; Braz, Carolina A; Rosa-e-Silva, Julio C; Candido-dos-Reis, Francisco J; Nogueira, Antonio A; Poli-Neto, Omero B

2015-12-01

Chronic pelvic pain is a common condition among women, and 10 to 30 % of causes originate from the abdominal wall, and are associated with trigger points. Although little is known about their pathophysiology, variable methods have been practiced clinically. The purpose of this study was to evaluate the efficacy of local anaesthetic injections versus ischemic compression via physical therapy for pain relief of abdominal wall trigger points in women with chronic pelvic pain. We conducted a parallel group randomized trial including 30 women with chronic pelvic pain with abdominal wall trigger points. Subjects were randomly assigned to one of two intervention groups. One group received an injection of 2 mL 0.5 % lidocaine without a vasoconstrictor into a trigger point. In the other group, ischemic compression via physical therapy was administered at the trigger points three times, with each session lasting for 60 s, and a rest period of 30 s between applications. Both treatments were administered during one weekly session for four weeks. Our primary outcomes were satisfactory clinical response rates and percentages of pain relief. Our secondary outcomes are pain threshold and tolerance at the trigger points. All subjects were evaluated at baseline and 1, 4, and 12 weeks after the interventions. The study was conducted at a tertiary hospital that was associated with a university providing assistance predominantly to working class women who were treated by the public health system. Clinical response rates and pain relief were significantly better at 1, 4, and 12 weeks for those receiving local anaesthetic injections than ischemic compression via physical therapy. The pain relief of women treated with local anaesthetic injections progressively improved at 1, 4, and 12 weeks after intervention. In contrast, women treated with ischemic compression did not show considerable changes in pain relief after intervention. In the local anaesthetic injection group, pain threshold and tolerance improved with time in the absence of significant differences between groups. Lidocaine injection seems to be better for reducing the severity of chronic pelvic pain secondary to abdominal wall trigger points compared to ischemic compression via physical therapy. ClinicalTrials.gov NCT00628355. Date of registration: February 25, 2008.

[Myofascial pain syndrome--frequent occurrence and often misdiagnosed].

PubMed

Pongratz, D E; Späth, M

1998-09-30

Myofascial pain syndrome (MPS) is a very common localized--sometimes also polytopic--painful musculoskeletal condition associated with trigger points, for which, however, diagnostic criteria established in well-designed studies are still lacking. These two facts form the basis for differentiating between MPS and the fibromyalgia syndrome. The difference between trigger points (MPS) and tender points (fibromyalgia) is of central importance--not merely in a linguistic sense. A knowledge of the signs and symptoms typically associated with a trigger point often obviates the need for time-consuming and expensive technical diagnostic measures. The assumption that many cases of unspecific complaints affecting the musculoskeletal system may be ascribed to MPS makes clear the scope for the saving of costs.

Heterotypic endosomal fusion as an initial trigger for insulin-induced glucose transporter 4 (GLUT4) translocation in skeletal muscle.

PubMed

Hatakeyama, Hiroyasu; Kanzaki, Makoto

2017-08-15

Comprehensive imaging analyses of glucose transporter 4 (GLUT4) behaviour in mouse skeletal muscle was conducted. Quantum dot-based single molecule nanometry revealed that GLUT4 molecules in skeletal myofibres are governed by regulatory systems involving 'static retention' and 'stimulus-dependent liberation'. Vital imaging analyses and super-resolution microscopy-based morphometry demonstrated that insulin liberates the GLUT4 molecule from its static state by triggering acute heterotypic endomembrane fusion arising from the very small GLUT4-containing vesicles in skeletal myofibres. Prior exposure to exercise-mimetic stimuli potentiated this insulin-responsive endomembrane fusion event involving GLUT4-containing vesicles, suggesting that this endomembranous regulation process is a potential site related to the effects of exercise. Skeletal muscle is the major systemic glucose disposal site. Both insulin and exercise facilitate translocation of the glucose transporter glucose transporter 4 (GLUT4) via distinct signalling pathways and exercise also enhances insulin sensitivity. However, the trafficking mechanisms controlling GLUT4 mobilization in skeletal muscle remain poorly understood as a resuly of technical limitations. In the present study, which employs various imaging techniques on isolated skeletal myofibres, we show that one of the initial triggers of insulin-induced GLUT4 translocation is heterotypic endomembrane fusion arising from very small static GLUT4-containing vesicles with a subset of transferrin receptor-containing endosomes. Importantly, pretreatment with exercise-mimetic stimuli potentiated the susceptibility to insulin responsiveness, as indicated by these acute endomembranous activities. We also found that AS160 exhibited stripe-like localization close to sarcomeric α-actinin and that insulin induced a reduction of the stripe-like localization accompanying changes in its detergent solubility. The results of the present study thus provide a conceptual framework indicating that GLUT4 protein trafficking via heterotypic fusion is a critical feature of GLUT4 translocation in skeletal muscles and also suggest that the efficacy of the endomembranous fusion process in response to insulin is involved in the benefits of exercise. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

A forced damped oscillation framework for undulatory swimming provides new insights into how propulsion arises in active and passive swimming.

PubMed

Bhalla, Amneet Pal Singh; Griffith, Boyce E; Patankar, Neelesh A

2013-01-01

A fundamental issue in locomotion is to understand how muscle forcing produces apparently complex deformation kinematics leading to movement of animals like undulatory swimmers. The question of whether complicated muscle forcing is required to create the observed deformation kinematics is central to the understanding of how animals control movement. In this work, a forced damped oscillation framework is applied to a chain-link model for undulatory swimming to understand how forcing leads to deformation and movement. A unified understanding of swimming, caused by muscle contractions ("active" swimming) or by forces imparted by the surrounding fluid ("passive" swimming), is obtained. We show that the forcing triggers the first few deformation modes of the body, which in turn cause the translational motion. We show that relatively simple forcing patterns can trigger seemingly complex deformation kinematics that lead to movement. For given muscle activation, the forcing frequency relative to the natural frequency of the damped oscillator is important for the emergent deformation characteristics of the body. The proposed approach also leads to a qualitative understanding of optimal deformation kinematics for fast swimming. These results, based on a chain-link model of swimming, are confirmed by fully resolved computational fluid dynamics (CFD) simulations. Prior results from the literature on the optimal value of stiffness for maximum speed are explained.

A Forced Damped Oscillation Framework for Undulatory Swimming Provides New Insights into How Propulsion Arises in Active and Passive Swimming

PubMed Central

Bhalla, Amneet Pal Singh; Griffith, Boyce E.; Patankar, Neelesh A.

2013-01-01

A fundamental issue in locomotion is to understand how muscle forcing produces apparently complex deformation kinematics leading to movement of animals like undulatory swimmers. The question of whether complicated muscle forcing is required to create the observed deformation kinematics is central to the understanding of how animals control movement. In this work, a forced damped oscillation framework is applied to a chain-link model for undulatory swimming to understand how forcing leads to deformation and movement. A unified understanding of swimming, caused by muscle contractions (“active” swimming) or by forces imparted by the surrounding fluid (“passive” swimming), is obtained. We show that the forcing triggers the first few deformation modes of the body, which in turn cause the translational motion. We show that relatively simple forcing patterns can trigger seemingly complex deformation kinematics that lead to movement. For given muscle activation, the forcing frequency relative to the natural frequency of the damped oscillator is important for the emergent deformation characteristics of the body. The proposed approach also leads to a qualitative understanding of optimal deformation kinematics for fast swimming. These results, based on a chain-link model of swimming, are confirmed by fully resolved computational fluid dynamics (CFD) simulations. Prior results from the literature on the optimal value of stiffness for maximum speed are explained. PMID:23785272

Macrophages commit postnatal endothelium-derived progenitors to angiogenesis and restrict endothelial to mesenchymal transition during muscle regeneration.

PubMed

Zordan, P; Rigamonti, E; Freudenberg, K; Conti, V; Azzoni, E; Rovere-Querini, P; Brunelli, S

2014-01-30

The damage of the skeletal muscle prompts a complex and coordinated response that involves the interactions of many different cell populations and promotes inflammation, vascular remodeling and finally muscle regeneration. Muscle disorders exist in which the irreversible loss of tissue integrity and function is linked to defective neo-angiogenesis with persistence of tissue necrosis and inflammation. Here we show that macrophages (MPs) are necessary for efficient vascular remodeling in the injured muscle. In particular, MPs sustain the differentiation of endothelial-derived progenitors to contribute to neo-capillary formation, by secreting pro-angiogenic growth factors. When phagocyte infiltration is compromised endothelial-derived progenitors undergo a significant endothelial to mesenchymal transition (EndoMT), possibly triggered by the activation of transforming growth factor-β/bone morphogenetic protein signaling, collagen accumulates and the muscle is replaced by fibrotic tissue. Our findings provide new insights in EndoMT in the adult skeletal muscle, and suggest that endothelial cells in the skeletal muscle may represent a new target for therapeutic intervention in fibrotic diseases.

Cut-off Points for Muscle Mass - Not Grip Strength or Gait Speed - Determine Variations in Sarcopenia Prevalence.

PubMed

Masanés, F; Rojano I Luque, X; Salvà, A; Serra-Rexach, J A; Artaza, I; Formiga, F; Cuesta, F; López Soto, A; Ruiz, D; Cruz-Jentoft, A J

2017-01-01

The European Working Group on Sarcopenia in Older People (EWGSOP) has proposed different methods and cut-off points for the three parameters that define sarcopenia: muscle mass, muscle strength and physical performance. Although this facilitates clinical practice, it limits comparability between studies and leads to wide differences in published prevalence rates. The aim of this study was to assess how changes in cut-off points for muscle mass, gait speed and grip strength affected sarcopenia prevalence according to EWGSOP criteria. Cross-sectional analysis of elderly individuals recruited from outpatient clinics (n=298) and nursing homes (n=276). We measured muscle mass, grip strength and gait speed and assessed how changes in cut-off points changed sarcopenia prevalence in both populations. An increase from 5.45 kg/m2 to 6.68 kg/m2 in the muscle mass index for female outpatients and nursing-home residents increased sarcopenia prevalence from 4% to 23% and from 9% to 47%, respectively; for men, for an increase from 7.25 kg/m2 to 8.87 kg/m2, the corresponding increases were from 1% to 22% and from 6% to 41%, respectively. Changes in gait speed and grip strength had a limited impact on sarcopenia prevalence. The cut-off points used for muscle mass affect the reported prevalence rates for sarcopenia and, in turn, affect comparability between studies. The main factors influencing the magnitude of the change are muscle mass index distribution in the population and the absolute value of the cut-off points: the same difference between two references (e.g., 7.5 kg/m2 to 7.75 kg/m2 or 7.75 kg/m2 to 8 kg/m2) may produce different changes in prevalence. Changes in cut-off points for gait speed and grip strength had a limited impact on sarcopenia prevalence and on study comparability.

ROS Production via P2Y1-PKC-NOX2 Is Triggered by Extracellular ATP after Electrical Stimulation of Skeletal Muscle Cells.

PubMed

Díaz-Vegas, Alexis; Campos, Cristian A; Contreras-Ferrat, Ariel; Casas, Mariana; Buvinic, Sonja; Jaimovich, Enrique; Espinosa, Alejandra

2015-01-01

During exercise, skeletal muscle produces reactive oxygen species (ROS) via NADPH oxidase (NOX2) while inducing cellular adaptations associated with contractile activity. The signals involved in this mechanism are still a matter of study. ATP is released from skeletal muscle during electrical stimulation and can autocrinely signal through purinergic receptors; we searched for an influence of this signal in ROS production. The aim of this work was to characterize ROS production induced by electrical stimulation and extracellular ATP. ROS production was measured using two alternative probes; chloromethyl-2,7- dichlorodihydrofluorescein diacetate or electroporation to express the hydrogen peroxide-sensitive protein Hyper. Electrical stimulation (ES) triggered a transient ROS increase in muscle fibers which was mimicked by extracellular ATP and was prevented by both carbenoxolone and suramin; antagonists of pannexin channel and purinergic receptors respectively. In addition, transient ROS increase was prevented by apyrase, an ecto-nucleotidase. MRS2365, a P2Y1 receptor agonist, induced a large signal while UTPyS (P2Y2 agonist) elicited a much smaller signal, similar to the one seen when using ATP plus MRS2179, an antagonist of P2Y1. Protein kinase C (PKC) inhibitors also blocked ES-induced ROS production. Our results indicate that physiological levels of electrical stimulation induce ROS production in skeletal muscle cells through release of extracellular ATP and activation of P2Y1 receptors. Use of selective NOX2 and PKC inhibitors suggests that ROS production induced by ES or extracellular ATP is mediated by NOX2 activated by PKC.

Measuring the motor output of the pontomedullary reticular formation in the monkey: do stimulus-triggered averaging and stimulus trains produce comparable results in the upper limbs?

PubMed

Herbert, Wendy J; Davidson, Adam G; Buford, John A

2010-06-01

The pontomedullary reticular formation (PMRF) of the monkey produces motor outputs to both upper limbs. EMG effects evoked from stimulus-triggered averaging (StimulusTA) were compared with effects from stimulus trains to determine whether both stimulation methods produced comparable results. Flexor and extensor muscles of scapulothoracic, shoulder, elbow, and wrist joints were studied bilaterally in two male M. fascicularis monkeys trained to perform a bilateral reaching task. The frequency of facilitation versus suppression responses evoked in the muscles was compared between methods. Stimulus trains were more efficient (94% of PMRF sites) in producing responses than StimulusTA (55%), and stimulus trains evoked responses from more muscles per site than from StimulusTA. Facilitation (72%) was more common from stimulus trains than StimulusTA (39%). In the overall results, a bilateral reciprocal activation pattern of ipsilateral flexor and contralateral extensor facilitation was evident for StimulusTA and stimulus trains. When the comparison was restricted to cases where both methods produced a response in a given muscle from the same site, agreement was very high, at 80%. For the remaining 20%, discrepancies were accounted for mainly by facilitation from stimulus trains when StimulusTA produced suppression, which was in agreement with the under-representation of suppression in the stimulus train data as a whole. To the extent that the stimulus train method may favor transmission through polysynaptic pathways, these results suggest that polysynaptic pathways from the PMRF more often produce facilitation in muscles that would typically demonstrate suppression with StimulusTA.

Ryanodine receptor fragmentation and sarcoplasmic reticulum Ca2+ leak after one session of high-intensity interval exercise

PubMed Central

Place, Nicolas; Ivarsson, Niklas; Venckunas, Tomas; Neyroud, Daria; Brazaitis, Marius; Cheng, Arthur J.; Ochala, Julien; Kamandulis, Sigitas; Girard, Sebastien; Volungevičius, Gintautas; Paužas, Henrikas; Mekideche, Abdelhafid; Kayser, Bengt; Martinez-Redondo, Vicente; Bruton, Joseph; Truffert, Andre; Lanner, Johanna T.; Skurvydas, Albertas; Westerblad, Håkan

2015-01-01

High-intensity interval training (HIIT) is a time-efficient way of improving physical performance in healthy subjects and in patients with common chronic diseases, but less so in elite endurance athletes. The mechanisms underlying the effectiveness of HIIT are uncertain. Here, recreationally active human subjects performed highly demanding HIIT consisting of 30-s bouts of all-out cycling with 4-min rest in between bouts (≤3 min total exercise time). Skeletal muscle biopsies taken 24 h after the HIIT exercise showed an extensive fragmentation of the sarcoplasmic reticulum (SR) Ca2+ release channel, the ryanodine receptor type 1 (RyR1). The HIIT exercise also caused a prolonged force depression and triggered major changes in the expression of genes related to endurance exercise. Subsequent experiments on elite endurance athletes performing the same HIIT exercise showed no RyR1 fragmentation or prolonged changes in the expression of endurance-related genes. Finally, mechanistic experiments performed on isolated mouse muscles exposed to HIIT-mimicking stimulation showed reactive oxygen/nitrogen species (ROS)-dependent RyR1 fragmentation, calpain activation, increased SR Ca2+ leak at rest, and depressed force production due to impaired SR Ca2+ release upon stimulation. In conclusion, HIIT exercise induces a ROS-dependent RyR1 fragmentation in muscles of recreationally active subjects, and the resulting changes in muscle fiber Ca2+-handling trigger muscular adaptations. However, the same HIIT exercise does not cause RyR1 fragmentation in muscles of elite endurance athletes, which may explain why HIIT is less effective in this group. PMID:26575622

Ryanodine receptor fragmentation and sarcoplasmic reticulum Ca2+ leak after one session of high-intensity interval exercise.

PubMed

Place, Nicolas; Ivarsson, Niklas; Venckunas, Tomas; Neyroud, Daria; Brazaitis, Marius; Cheng, Arthur J; Ochala, Julien; Kamandulis, Sigitas; Girard, Sebastien; Volungevičius, Gintautas; Paužas, Henrikas; Mekideche, Abdelhafid; Kayser, Bengt; Martinez-Redondo, Vicente; Ruas, Jorge L; Bruton, Joseph; Truffert, Andre; Lanner, Johanna T; Skurvydas, Albertas; Westerblad, Håkan

2015-12-15

High-intensity interval training (HIIT) is a time-efficient way of improving physical performance in healthy subjects and in patients with common chronic diseases, but less so in elite endurance athletes. The mechanisms underlying the effectiveness of HIIT are uncertain. Here, recreationally active human subjects performed highly demanding HIIT consisting of 30-s bouts of all-out cycling with 4-min rest in between bouts (≤3 min total exercise time). Skeletal muscle biopsies taken 24 h after the HIIT exercise showed an extensive fragmentation of the sarcoplasmic reticulum (SR) Ca(2+) release channel, the ryanodine receptor type 1 (RyR1). The HIIT exercise also caused a prolonged force depression and triggered major changes in the expression of genes related to endurance exercise. Subsequent experiments on elite endurance athletes performing the same HIIT exercise showed no RyR1 fragmentation or prolonged changes in the expression of endurance-related genes. Finally, mechanistic experiments performed on isolated mouse muscles exposed to HIIT-mimicking stimulation showed reactive oxygen/nitrogen species (ROS)-dependent RyR1 fragmentation, calpain activation, increased SR Ca(2+) leak at rest, and depressed force production due to impaired SR Ca(2+) release upon stimulation. In conclusion, HIIT exercise induces a ROS-dependent RyR1 fragmentation in muscles of recreationally active subjects, and the resulting changes in muscle fiber Ca(2+)-handling trigger muscular adaptations. However, the same HIIT exercise does not cause RyR1 fragmentation in muscles of elite endurance athletes, which may explain why HIIT is less effective in this group.

Powered ankle-foot prosthesis to assist level-ground and stair-descent gaits.

PubMed

Au, Samuel; Berniker, Max; Herr, Hugh

2008-05-01

The human ankle varies impedance and delivers net positive work during the stance period of walking. In contrast, commercially available ankle-foot prostheses are passive during stance, causing many clinical problems for transtibial amputees, including non-symmetric gait patterns, higher gait metabolism, and poorer shock absorption. In this investigation, we develop and evaluate a myoelectric-driven, finite state controller for a powered ankle-foot prosthesis that modulates both impedance and power output during stance. The system employs both sensory inputs measured local to the external prosthesis, and myoelectric inputs measured from residual limb muscles. Using local prosthetic sensing, we first develop two finite state controllers to produce biomimetic movement patterns for level-ground and stair-descent gaits. We then employ myoelectric signals as control commands to manage the transition between these finite state controllers. To transition from level-ground to stairs, the amputee flexes the gastrocnemius muscle, triggering the prosthetic ankle to plantar flex at terminal swing, and initiating the stair-descent state machine algorithm. To transition back to level-ground walking, the amputee flexes the tibialis anterior muscle, triggering the ankle to remain dorsiflexed at terminal swing, and initiating the level-ground state machine algorithm. As a preliminary evaluation of clinical efficacy, we test the device on a transtibial amputee with both the proposed controller and a conventional passive-elastic control. We find that the amputee can robustly transition between the finite state controllers through direct muscle activation, allowing rapid transitioning from level-ground to stair walking patterns. Additionally, we find that the proposed finite state controllers result in a more biomimetic ankle response, producing net propulsive work during level-ground walking and greater shock absorption during stair descent. The results of this study highlight the potential of prosthetic leg controllers that exploit neural signals to trigger terrain-appropriate, local prosthetic leg behaviors.

Superoxide anion radical-triggered Ca2+ release from cardiac sarcoplasmic reticulum through ryanodine receptor Ca2+ channel.

PubMed

Kawakami, M; Okabe, E

1998-03-01

The ryanodine receptor Ca2+ channel (RyRC) constitutes the Ca2+-release pathway in sarcoplasmic reticulum (SR) of cardiac muscle. A direct mechanical and a Ca2+-triggered mechanism (Ca2+-induced Ca2+ release) have been proposed to explain the in situ activation of Ca2+ release in cardiac muscle. A variety of chemical oxidants have been shown to activate RyRC; however, the role of modification induced by oxygen-derived free radicals in pathological states of the muscle remains to be elucidated. It has been hypothesized that oxygen-derived free radicals initiate Ca2+-mediated functional changes in or damage to cardiac muscle by acting on the SR and promoting an increase in Ca2+ release. We confirmed that superoxide anion radical (O2-) generated from hypoxanthine-xanthine oxidase reaction decreases calmodulin content and increases 45Ca2+ efflux from the heavy fraction of canine cardiac SR vesicles; hypoxanthine-xanthine oxidase also decreases Ca2+ free within the intravesicular space of the SR with no effect on Ca2+-ATPase activity. Current fluctuations through single Ca2+-release channels have been monitored after incorporation into planar phospholipid bilayers. We demonstrate that activation of the channel by O2- is dependent of the presence of calmodulin and identified calmodulin as a functional mediator of O2--triggered Ca2+ release through the RyRC. For the first time, we show that O2- stimulates Ca2+ release from heavy SR vesicles and suggest the importance of accessory proteins such as calmodulin in modulating the effect of O2-. The decreased calmodulin content induced by oxygen-derived free radicals, especially O2-, is a likely mechanism of accumulation of cytosolic Ca2+ (due to increased Ca2+ release from SR) after reperfusion of the ischemic heart.

Coordinating Upper and Lower Body During FES-Assisted Transfers in Persons With Spinal Cord Injury in Order to Reduce Arm Support.

PubMed

Jovic, Jovana; Azevedo Coste, Christine; Fraisse, Philippe; Henkous, Sonia; Fattal, Charles

2015-12-01

The goal of this study is to minimize arm forces applied during sit-to-stand (STS) transfers in persons with spinal cord injury (SCI) by using functional electrical stimulation (FES) applied to lower limbs muscles. A new FES system has been used to automatically trigger muscle stimulation of the lower limbs, at the desired moment in regards to trunk motion. The objective was to decrease arm participation during STS motion of a person with complete paraplegia and low-level tetraplegia. Six participants with chronic SCI participated in the study. Participants with SCI were recruited to complete STS movement using a new system for FES-assisted STS transfer. All participants attended one muscle mapping session to test their muscles condition, two training sessions to become familiarized with the experimental setup, and two measurement sessions using the proposed system for FES-assisted STS movement. The applied arm forces during STS movement were recorded and analyzed for different stimulation onset values with respect to the maximal trunk acceleration signal using one-way ANOVA statistical test. Post-hoc analysis was performed using Tukey's method. The results of this study showed that the moment of the stimulation onset has an influence on the arm forces applied during the STS motion. The lowest values of arm forces were obtained for STS movements where the electrical stimulation was triggered before and around the time corresponding to the maximal value of the trunk acceleration signal. Lowest arm forces values were obtained for STS motions that were similar to those of healthy persons in terms of trunk movements and beginning of lower limb movements in regards to maximal trunk acceleration signal. The FES system was able to mimic the rising motion of a healthy individual by triggering the FES at the appropriate moment. This method could prove useful for pivot transfer, therapeutic or functional verticalization. © 2015 International Neuromodulation Society.

Loss of muscle mass: Current developments in cachexia and sarcopenia focused on biomarkers and treatment.

PubMed

Drescher, Cathleen; Konishi, Masaaki; Ebner, Nicole; Springer, Jochen

2016-01-01

Loss of muscle mass arises from an imbalance of protein synthesis and protein degradation. Potential triggers of muscle wasting and function are immobilization, loss of appetite, dystrophies and chronic diseases as well as aging. All these conditions lead to increased morbidity and mortality in patients, which makes it a timely matter to find new biomarkers to get a fast clinical diagnosis and to develop new therapies. This mini-review covers current developments in the field of biomarkers and drugs on cachexia and sarcopenia. Here, we reported about promising markers, e.g. tartrate-resistant acid phosphatase 5a (TRACP5a), and novel substances like Epigallocatechin-3-gallate (EGCg). In summary, the progress to combat muscle wasting is in full swing and perhaps diagnosis of muscle atrophy and of course patient treatments could be soon supported by improved and more helpful strategies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Equilibrium-point control of human elbow-joint movement under isometric environment by using multichannel functional electrical stimulation

PubMed Central

Matsui, Kazuhiro; Hishii, Yasuo; Maegaki, Kazuya; Yamashita, Yuto; Uemura, Mitsunori; Hirai, Hiroaki; Miyazaki, Fumio

2014-01-01

Functional electrical stimulation (FES) is considered an effective technique for aiding quadriplegic persons. However, the human musculoskeletal system has highly non-linearity and redundancy. It is thus difficult to stably and accurately control limbs using FES. In this paper, we propose a simple FES method that is consistent with the motion-control mechanism observed in humans. We focus on joint motion by a pair of agonist-antagonist muscles of the musculoskeletal system, and define the “electrical agonist-antagonist muscle ratio (EAA ratio)” and “electrical agonist-antagonist muscle activity (EAA activity)” in light of the agonist-antagonist muscle ratio and agonist-antagonist muscle activity, respectively, to extract the equilibrium point and joint stiffness from electromyography (EMG) signals. These notions, the agonist-antagonist muscle ratio and agonist-antagonist muscle activity, are based on the hypothesis that the equilibrium point and stiffness of the agonist-antagonist motion system are controlled by the central nervous system. We derived the transfer function between the input EAA ratio and force output of the end-point. We performed some experiments in an isometric environment using six subjects. This transfer-function model is expressed as a cascade-coupled dead time element and a second-order system. High-speed, high-precision, smooth control of the hand force were achieved through the agonist-antagonist muscle stimulation pattern determined by this transfer function model. PMID:24987326

Equilibrium-point control of human elbow-joint movement under isometric environment by using multichannel functional electrical stimulation.

PubMed

Matsui, Kazuhiro; Hishii, Yasuo; Maegaki, Kazuya; Yamashita, Yuto; Uemura, Mitsunori; Hirai, Hiroaki; Miyazaki, Fumio

2014-01-01

Functional electrical stimulation (FES) is considered an effective technique for aiding quadriplegic persons. However, the human musculoskeletal system has highly non-linearity and redundancy. It is thus difficult to stably and accurately control limbs using FES. In this paper, we propose a simple FES method that is consistent with the motion-control mechanism observed in humans. We focus on joint motion by a pair of agonist-antagonist muscles of the musculoskeletal system, and define the "electrical agonist-antagonist muscle ratio (EAA ratio)" and "electrical agonist-antagonist muscle activity (EAA activity)" in light of the agonist-antagonist muscle ratio and agonist-antagonist muscle activity, respectively, to extract the equilibrium point and joint stiffness from electromyography (EMG) signals. These notions, the agonist-antagonist muscle ratio and agonist-antagonist muscle activity, are based on the hypothesis that the equilibrium point and stiffness of the agonist-antagonist motion system are controlled by the central nervous system. We derived the transfer function between the input EAA ratio and force output of the end-point. We performed some experiments in an isometric environment using six subjects. This transfer-function model is expressed as a cascade-coupled dead time element and a second-order system. High-speed, high-precision, smooth control of the hand force were achieved through the agonist-antagonist muscle stimulation pattern determined by this transfer function model.

Low level laser therapy on injured rat muscle

NASA Astrophysics Data System (ADS)

Mantineo, M.; Pinheiro, J. P.; Morgado, A. M.

2013-06-01

Although studies show the clinical effectiveness of low level laser therapy (LLLT) in facilitating the muscle healing process, scientific evidence is still required to prove the effectiveness of LLLT and to clarify the cellular and molecular mechanisms triggered by irradiation. Here we evaluate the effect of different LLLT doses, using continuous illumination (830 nm), in the treatment of inflammation induced in the gastrocnemius muscle of Wistar rats, through the quantification of cytokines in systemic blood and histological analysis of muscle tissue. We verified that all applied doses produce an effect on reducing the number of inflammatory cells and the concentration of pro-inflammatory TNF-α and IL-1β cytokines. The best results were obtained for 40 mW. The results may suggest a biphasic dose response curve.

JAK/STAT signaling in Drosophila muscles controls the cellular immune response against parasitoid infection.

PubMed

Yang, Hairu; Kronhamn, Jesper; Ekström, Jens-Ola; Korkut, Gül Gizem; Hultmark, Dan

2015-12-01

The role of JAK/STAT signaling in the cellular immune response of Drosophila is not well understood. Here, we show that parasitoid wasp infection activates JAK/STAT signaling in somatic muscles of the Drosophila larva, triggered by secretion of the cytokines Upd2 and Upd3 from circulating hemocytes. Deletion of upd2 or upd3, but not the related os (upd1) gene, reduced the cellular immune response, and suppression of the JAK/STAT pathway in muscle cells reduced the encapsulation of wasp eggs and the number of circulating lamellocyte effector cells. These results suggest that JAK/STAT signaling in muscles participates in a systemic immune defense against wasp infection. © 2015 The Authors. Published under the terms of the CC BY 4.0 license.

Cardiac Sarcoidosis

MedlinePlus

... every part of the heart, including the electrical system, muscle, valves, arteries and surrounding tissue called the pericardium. It is important to remember CS can precede, follow, or occur as the same time ... of an immune system response to an unidentified trigger. Infectious agents as ...

HDAC4 preserves skeletal muscle structure following long-term denervation by mediating distinct cellular responses.

PubMed

Pigna, Eva; Renzini, Alessandra; Greco, Emanuela; Simonazzi, Elena; Fulle, Stefania; Mancinelli, Rosa; Moresi, Viviana; Adamo, Sergio

2018-02-24

Denervation triggers numerous molecular responses in skeletal muscle, including the activation of catabolic pathways and oxidative stress, leading to progressive muscle atrophy. Histone deacetylase 4 (HDAC4) mediates skeletal muscle response to denervation, suggesting the use of HDAC inhibitors as a therapeutic approach to neurogenic muscle atrophy. However, the effects of HDAC4 inhibition in skeletal muscle in response to long-term denervation have not been described yet. To further study HDAC4 functions in response to denervation, we analyzed mutant mice in which HDAC4 is specifically deleted in skeletal muscle. After an initial phase of resistance to neurogenic muscle atrophy, skeletal muscle with a deletion of HDAC4 lost structural integrity after 4 weeks of denervation. Deletion of HDAC4 impaired the activation of the ubiquitin-proteasome system, delayed the autophagic response, and dampened the OS response in skeletal muscle. Inhibition of the ubiquitin-proteasome system or the autophagic response, if on the one hand, conferred resistance to neurogenic muscle atrophy; on the other hand, induced loss of muscle integrity and inflammation in mice lacking HDAC4 in skeletal muscle. Moreover, treatment with the antioxidant drug Trolox prevented loss of muscle integrity and inflammation in in mice lacking HDAC4 in skeletal muscle, despite the resistance to neurogenic muscle atrophy. These results reveal new functions of HDAC4 in mediating skeletal muscle response to denervation and lead us to propose the combined use of HDAC inhibitors and antioxidant drugs to treat neurogenic muscle atrophy.

Harnessing bistability for directional propulsion of soft, untethered robots.

PubMed

Chen, Tian; Bilal, Osama R; Shea, Kristina; Daraio, Chiara

2018-05-29

In most macroscale robotic systems, propulsion and controls are enabled through a physical tether or complex onboard electronics and batteries. A tether simplifies the design process but limits the range of motion of the robot, while onboard controls and power supplies are heavy and complicate the design process. Here, we present a simple design principle for an untethered, soft swimming robot with preprogrammed, directional propulsion without a battery or onboard electronics. Locomotion is achieved by using actuators that harness the large displacements of bistable elements triggered by surrounding temperature changes. Powered by shape memory polymer (SMP) muscles, the bistable elements in turn actuate the robot's fins. Our robots are fabricated using a commercially available 3D printer in a single print. As a proof of concept, we show the ability to program a vessel, which can autonomously deliver a cargo and navigate back to the deployment point.

Muscle contraction increases carnitine uptake via translocation of OCTN2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Furuichi, Yasuro; Sugiura, Tomoko; Kato, Yukio

Highlights: Black-Right-Pointing-Pointer Muscle contraction augmented carnitine uptake into rat hindlimb muscles. Black-Right-Pointing-Pointer An increase in carnitine uptake was due to an intrinsic clearance, not blood flow. Black-Right-Pointing-Pointer Histochemical analysis showed sarcolemmal OCTN2 was emphasized after contraction. Black-Right-Pointing-Pointer OCTN2 protein in sarcolemmal fraction was increased in contracting muscles. -- Abstract: Since carnitine plays an important role in fat oxidation, influx of carnitine could be crucial for muscle metabolism. OCTN2 (SLC22A5), a sodium-dependent solute carrier, is assumed to transport carnitine into skeletal muscle cells. Acute regulation of OCTN2 activity in rat hindlimb muscles was investigated in response to electrically induced contractile activity.more » The tissue uptake clearance (CL{sub uptake}) of L-[{sup 3}H]carnitine during muscle contraction was examined in vivo using integration plot analysis. The CL{sub uptake} of [{sup 14}C]iodoantipyrine (IAP) was also determined as an index of tissue blood flow. To test the hypothesis that increased carnitine uptake involves the translocation of OCTN2, contraction-induced alteration in the subcellular localization of OCTN2 was examined. The CL{sub uptake} of L-[{sup 3}H]carnitine in the contracting muscles increased 1.4-1.7-fold as compared to that in the contralateral resting muscles (p < 0.05). The CL{sub uptake} of [{sup 14}C]IAP was much higher than that of L-[{sup 3}H]carnitine, but no association between the increase in carnitine uptake and blood flow was obtained. Co-immunostaining of OCTN2 and dystrophin (a muscle plasma membrane marker) showed an increase in OCTN2 signal in the plasma membrane after muscle contraction. Western blotting showed that the level of sarcolemmal OCTN2 was greater in contracting muscles than in resting muscles (p < 0.05). The present study showed that muscle contraction facilitated carnitine uptake in skeletal muscles, possibly via the contraction-induced translocation of its specific transporter OCTN2 to the plasma membrane.« less

Effects of physical activity programmes in the workplace (PAPW) on the perception and intensity of musculoskeletal pain experienced by garment workers.

PubMed

Pereira, Cynara Cristina Domingues Alves; López, Ramón Fabian Alonso; Vilarta, Roberto

2013-01-01

The physical activity programmes in the workplace (PAPW) are applied to minimize the prevalence, incidence and intensity of pain. This study evaluated the perception of pain and quantifies its intensity among garment workers before and after performing a PAPW. We included 61 workers of a clothing company, who were classified randomly into experimental group (n = 44) 28.7 ± 8.8 years old and a control group (n = 17) 27.8 ± 7.4 years (20-43 years). The Trigger Points test questionnaire was used to assess pain perception and quantify its intensity. The PAPW was conducted in 15-minute sessions per day, consisting of stretching exercises (40%), muscular endurance (40%), self-massage relaxation and massage techniques (10%), and group dynamics (10%). The garment workers who participated in the PAPW showed a significant reduction of pain felt in the neck and wrists, and also a reduction in pain intensity in shoulders, arms, fingers and wrists that are most often strained during sewing. Our findings suggest that PAPW that target muscle groups that are more tense in sewing tasks, may be considered by companies for supporting adaptation to the work environment and improving health by reducing muscle and joint pain.

Diagnosis and treatment of abnormal dental pain.

PubMed

Fukuda, Ken-Ichi

2016-03-01

Most dental pain is caused by an organic problem such as dental caries, periodontitis, pulpitis, or trauma. Diagnosis and treatment of these symptoms are relatively straightforward. However, patients often also complain of abnormal dental pain that has a non-dental origin, whose diagnosis is challenging. Such abnormal dental pain can be categorized on the basis of its cause as referred pain, neuromodulatory pain, and neuropathic pain. When it is difficult to diagnose a patient's dental pain, these potential alternate causes should be considered. In this clinical review, we have presented a case of referred pain from the digastric muscle (Patient 1), of pulpectomized (Patient 2), and of pulpectomized pain (Patient 3) to illustrate referred, neuromodulatory, and neuropathic pain, respectively. The Patient 1 was advised muscle stretching and gentle massage of the trigger points, as well as pain relief using a nonsteroidal anti-inflammatory and the tricyclic antidepressant amitriptyline. The pain in Patient 2 was relieved completely by the tricyclic antidepressant amitriptyline. In Patient 3, the pain was controlled using either a continuous drip infusion of adenosine triphosphate or intravenous Mg2+ and lidocaine administered every 2 weeks. In each case of abnormal dental pain, the patient's diagnostic chart was used (Fig.2 and 3). Pain was satisfactorily relieved in all cases.

Immediate and short-term effects of the combination of dry needling and percutaneous TENS on post-needling soreness in patients with chronic myofascial neck pain

PubMed Central

León-Hernández, Jose V.; Martín-Pintado-Zugasti, Aitor; Frutos, Laura G.; Alguacil-Diego, Isabel M.; de la Llave-Rincón, Ana I.; Fernandez-Carnero, Josue

2016-01-01

ABSTRACT Background Dry needling (DN) and percutaneous electrical nerve stimulation (PENS) are widely used techniques in the treatment of myofascial pain. Objective To investigate the immediate and short-term effects of the combination of DN and PENS compared to DN alone on the upper trapezius muscle. Method This is a 72-hour follow-up single-blinded randomized controlled trial. Sixty-two volunteer patients with chronic myofascial neck pain with active Myofascial Trigger Points (MTrPs) in the upper trapezius muscle were recruited. Randomization was performed, and 31 patients received DN treatment (DN group) and 31 received DN and PENS (DN+PENS group). The primary outcomes were neck disability index (NDI) and visual analog scale for pain for both post-needling soreness (PNS) and neck pain intensity (NPI). Pressure pain threshold (PPT) and cervical range of motion (CROM) were the secondary outcomes. Results We detected between-group differences in NPI and PNS in favor of the DN+PENS group immediately after treatment. No between-group differences in NDI were observed. Conclusion PENS application after dry needling treatment is more effective than dry needling alone for decreasing soreness in the short term and improving neck pain intensity immediately in patients with myofascial chronic neck pain. PMID:27410163

Intraspinal microstimulation and diaphragm activation after cervical spinal cord injury

PubMed Central

Mercier, L. M.; Gonzalez-Rothi, E. J.; Streeter, K. A.; Posgai, S. S.; Poirier, A. S.; Fuller, D. D.; Reier, P. J.

2016-01-01

Intraspinal microstimulation (ISMS) using implanted electrodes can evoke locomotor movements after spinal cord injury (SCI) but has not been explored in the context of respiratory motor output. An advantage over epidural and direct muscle stimulation is the potential of ISMS to selectively stimulate components of the spinal respiratory network. The present study tested the hypothesis that medullary respiratory activity could be used to trigger midcervical ISMS and diaphragm motor unit activation in rats with cervical SCI. Studies were conducted after acute (hours) and subacute (5–21 days) C2 hemisection (C2Hx) injury in adult rats. Inspiratory bursting in the genioglossus (tongue) muscle was used to trigger a 250-ms train stimulus (100 Hz, 100–200 μA) to the ventral C4 spinal cord, targeting the phrenic motor nucleus. After both acute and subacute injury, genioglossus EMG activity effectively triggered ISMS and activated diaphragm motor units during the inspiratory phase. The ISMS paradigm also evoked short-term potentiation of spontaneous inspiratory activity in the previously paralyzed hemidiaphragm (i.e., bursting persisting beyond the stimulus period) in ∼70% of the C2Hx animals. We conclude that medullary inspiratory output can be used to trigger cervical ISMS and diaphragm activity after SCI. Further refinement of this method may enable “closed-loop-like” ISMS approaches to sustain ventilation after severe SCI. NEW & NOTEWORTHY We examined the feasibility of using intraspinal microstimulation (ISMS) of the cervical spinal cord to evoke diaphragm activity ipsilateral to acute and subacute hemisection of the upper cervical spinal cord of the rat. This proof-of-concept study demonstrated the efficacy of diaphragm activation, using an upper airway respiratory EMG signal to trigger ISMS at the level of the ipsilesional phrenic nucleus during acute and advanced postinjury intervals. PMID:27881723

Anatomic variations found on dissection of depressor septi nasi muscles in cadavers.

PubMed

Ebrahimi, Ali; Nejadsarvari, Nasrin; Motamedi, Mohammad Hosein Kalantar; Rezaee, Maryam; Koushki, Ehsan Shams

2012-01-01

To define variations of the depressor septi muscle in Iranians; to provide guidance for modification of this muscle during rhinoplasty in patients with an active muscle and short upper lip; and to correlate our findings with our clinical experience to develop the applied algorithms. This study was conducted by dissecting 82 depressor septi nasi muscles in 41 Iranian cadavers. Origin and insertion points of each muscle were studied. Three variations were found in muscle insertion points: periosteal, orbicularis oris, and floating. Forty-four percent of the muscles were inserted into the periosteum of the maxilla (n = 36); 39% of muscles were inserted into the orbicularis oris muscle (n = 32); and 17% were diminutive or floating (n = 14). Periosteal insertion was thicker and stronger than the other variations. In all cadavers, the origin of the muscle was medial crus of alar cartilage and caudal of the nasal septum. This cadaveric dissection showed that the percentage of depressor septi muscle insertions is not similar to that found in other surveys. In this study, periosteal insertion of the depressor septi muscle was the most common variation.

Muscle Mitochondrial Uncoupling Dismantles Neuromuscular Junction and Triggers Distal Degeneration of Motor Neurons

PubMed Central

Dupuis, Luc; Gonzalez de Aguilar, Jose-Luis; Echaniz-Laguna, Andoni; Eschbach, Judith; Rene, Frédérique; Oudart, Hugues; Halter, Benoit; Huze, Caroline; Schaeffer, Laurent; Bouillaud, Frédéric; Loeffler, Jean-Philippe

2009-01-01

Background Amyotrophic lateral sclerosis (ALS), the most frequent adult onset motor neuron disease, is associated with hypermetabolism linked to defects in muscle mitochondrial energy metabolism such as ATP depletion and increased oxygen consumption. It remains unknown whether muscle abnormalities in energy metabolism are causally involved in the destruction of neuromuscular junction (NMJ) and subsequent motor neuron degeneration during ALS. Methodology/Principal Findings We studied transgenic mice with muscular overexpression of uncoupling protein 1 (UCP1), a potent mitochondrial uncoupler, as a model of muscle restricted hypermetabolism. These animals displayed age-dependent deterioration of the NMJ that correlated with progressive signs of denervation and a mild late-onset motor neuron pathology. NMJ regeneration and functional recovery were profoundly delayed following injury of the sciatic nerve and muscle mitochondrial uncoupling exacerbated the pathology of an ALS animal model. Conclusions/Significance These findings provide the proof of principle that a muscle restricted mitochondrial defect is sufficient to generate motor neuron degeneration and suggest that therapeutic strategies targeted at muscle metabolism might prove useful for motor neuron diseases. PMID:19404401

Development of mapped stress-field boundary conditions based on a Hill-type muscle model.

PubMed

Cardiff, P; Karač, A; FitzPatrick, D; Flavin, R; Ivanković, A

2014-09-01

Forces generated in the muscles and tendons actuate the movement of the skeleton. Accurate estimation and application of these musculotendon forces in a continuum model is not a trivial matter. Frequently, musculotendon attachments are approximated as point forces; however, accurate estimation of local mechanics requires a more realistic application of musculotendon forces. This paper describes the development of mapped Hill-type muscle models as boundary conditions for a finite volume model of the hip joint, where the calculated muscle fibres map continuously between attachment sites. The applied muscle forces are calculated using active Hill-type models, where input electromyography signals are determined from gait analysis. Realistic muscle attachment sites are determined directly from tomography images. The mapped muscle boundary conditions, implemented in a finite volume structural OpenFOAM (ESI-OpenCFD, Bracknell, UK) solver, are employed to simulate the mid-stance phase of gait using a patient-specific natural hip joint, and a comparison is performed with the standard point load muscle approach. It is concluded that physiological joint loading is not accurately represented by simplistic muscle point loading conditions; however, when contact pressures are of sole interest, simplifying assumptions with regard to muscular forces may be valid. Copyright © 2014 John Wiley & Sons, Ltd.

Spatially localized phosphorous metabolism of skeletal muscle in Duchenne muscular dystrophy patients: 24-month follow-up.

PubMed

Hooijmans, M T; Doorenweerd, N; Baligand, C; Verschuuren, J J G M; Ronen, I; Niks, E H; Webb, A G; Kan, H E

2017-01-01

To assess the changes in phosphodiester (PDE)-levels, detected by 31P magnetic resonance spectroscopy (MRS), over 24-months to determine the potential of PDE as marker for muscle tissue changes in Duchenne Muscular Dystrophy (DMD) patients. Spatially resolved phosphorous datasets were acquired in the right lower leg of 18 DMD patients (range: 5-15.4 years) and 12 age-matched healthy controls (range: 5-14 years) at three time-points (baseline, 12-months, and 24-months) using a 7T MR-System (Philips Achieva). 3-point Dixon images were acquired at 3T (Philips Ingenia) to determine muscle fat fraction. Analyses were done for six muscles that represent different stages of muscle wasting. Differences between groups and time-points were assessed with non-parametric tests with correction for multiple comparisons. Coefficient of variance (CV) were determined for PDE in four healthy adult volunteers in high and low signal-to-noise ratio (SNR) datasets. PDE-levels were significantly higher (two-fold) in DMD patients compared to controls in all analyzed muscles at almost every time point and did not change over the study period. Fat fraction was significantly elevated in all muscles at all time points compared to healthy controls, and increased significantly over time, except in the tibialis posterior muscle. The mean within subject CV for PDE-levels was 4.3% in datasets with high SNR (>10:1) and 5.7% in datasets with low SNR. The stable two-fold increase in PDE-levels found in DMD patients in muscles with different levels of muscle wasting over 2-year time, including DMD patients as young as 5.5 years-old, suggests that PDE-levels may increase very rapidly early in the disease process and remain elevated thereafter. The low CV values in high and low SNR datasets show that PDE-levels can be accurately and reproducibly quantified in all conditions. Our data confirms the great potential of PDE as a marker for muscle tissue changes in DMD patients.

Spatially localized phosphorous metabolism of skeletal muscle in Duchenne muscular dystrophy patients: 24–month follow-up

PubMed Central

Doorenweerd, N.; Baligand, C.; Verschuuren, J. J. G. M.; Ronen, I.; Niks, E. H.; Webb, A. G.; Kan, H. E.

2017-01-01

Objectives To assess the changes in phosphodiester (PDE)-levels, detected by 31P magnetic resonance spectroscopy (MRS), over 24-months to determine the potential of PDE as marker for muscle tissue changes in Duchenne Muscular Dystrophy (DMD) patients. Methods Spatially resolved phosphorous datasets were acquired in the right lower leg of 18 DMD patients (range: 5–15.4 years) and 12 age-matched healthy controls (range: 5–14 years) at three time-points (baseline, 12-months, and 24-months) using a 7T MR-System (Philips Achieva). 3-point Dixon images were acquired at 3T (Philips Ingenia) to determine muscle fat fraction. Analyses were done for six muscles that represent different stages of muscle wasting. Differences between groups and time-points were assessed with non-parametric tests with correction for multiple comparisons. Coefficient of variance (CV) were determined for PDE in four healthy adult volunteers in high and low signal-to-noise ratio (SNR) datasets. Results PDE-levels were significantly higher (two-fold) in DMD patients compared to controls in all analyzed muscles at almost every time point and did not change over the study period. Fat fraction was significantly elevated in all muscles at all time points compared to healthy controls, and increased significantly over time, except in the tibialis posterior muscle. The mean within subject CV for PDE-levels was 4.3% in datasets with high SNR (>10:1) and 5.7% in datasets with low SNR. Discussion and conclusion The stable two-fold increase in PDE-levels found in DMD patients in muscles with different levels of muscle wasting over 2-year time, including DMD patients as young as 5.5 years-old, suggests that PDE-levels may increase very rapidly early in the disease process and remain elevated thereafter. The low CV values in high and low SNR datasets show that PDE-levels can be accurately and reproducibly quantified in all conditions. Our data confirms the great potential of PDE as a marker for muscle tissue changes in DMD patients. PMID:28763477

ELECTRONIC TRIGGER CIRCUIT

DOEpatents

Russell, J.A.G.

1958-01-01

An electronic trigger circuit is described of the type where an output pulse is obtained only after an input voltage has cqualed or exceeded a selected reference voltage. In general, the invention comprises a source of direct current reference voltage in series with an impedance and a diode rectifying element. An input pulse of preselected amplitude causes the diode to conduct and develop a signal across the impedance. The signal is delivered to an amplifier where an output pulse is produced and part of the output is fed back in a positive manner to the diode so that the amplifier produces a steep wave front trigger pulsc at the output. The trigger point of the described circuit is not subject to variation due to the aging, etc., of multi-electrode tabes, since the diode circuit essentially determines the trigger point.

Anatomical study of phrenic nerve course in relation to neck dissection.

PubMed

Hamada, Tomohiro; Usami, Akinobu; Kishi, Asuka; Kon, Hideki; Takada, Satoshi

2015-04-01

The present study sought to clarify the course of the phrenic nerve and its correlation with anatomical landmarks in the neck region. We examined 17 cadavers (30 sides). In each, the phrenic nerves was dissected from the lateral side of the neck, and its position within the triangle formed by the mastoid process and sternal and acromial ends of the clavicle was determined. The point where the phrenic nerve arises in the posterior triangle was found to be similar to the point where the cutaneous blanches of the cervical plexus emerge at the middle of the posterior border of the sternocleidomastoid muscle. In the supraclavian triangle, the phrenic nerve crosses the anterior border of the anterior scalene muscle near Erb's point where the superficial point is 2-3 cm superior from the clavicle and posterior border of the sternocleidomastoid muscle. The phrenic nerve arises in the posterior triangle near the nerve point, then descends to the anterior surface of the anterior scalene muscle in the supraclavian triangle. It is necessary to be aware of the supraclavian triangle below Erb's point during neck dissection procedures.

[Cellular mechanism of the generation of spontaneous activity in gastric muscle].

PubMed

Nakamura, Eri; Kito, Yoshihiko; Fukuta, Hiroyasu; Yanai, Yoshimasa; Hashitani, Hikaru; Yamamoto, Yoshimichi; Suzuki, Hikaru

2004-03-01

In gastric smooth muscles, interstitial cells of Cajal (ICC) might be the pacemaker cells of spontaneous activities since ICC are rich in mitochondria and are connected with smooth muscle cells via gap junctions. Several types of ICC are distributed widely in the stomach wall. A group of ICC distributed in the myenteric layer (ICC-MY) were the pacemaker cells of gastrointestinal smooth muscles. Pacemaker potentials were generated in ICC-MY, and the potentials were conducted to circular smooth muscles to trigger slow waves and also conducted to longitudinal muscles to form follower potentials. In circular muscle preparations, interstitial cells distributed within muscle bundles (ICC-IM) produced unitary potentials, which were conducted to circular muscles to form slow potentials by summation. In mutant mice lacking inositol trisphosphate (IP(3)) receptor, slow waves were absent in gastric smooth muscles. The generation of spontaneous activity was impaired by the inhibition of Ca(2+)-release from internal stores through IP(3) receptors, inhibition of mitochondrial Ca(2+)-handling with proton pump inhibitors, and inhibition of ATP-sensitive K(+)-channels at the mitochondrial inner membrane. These results suggested that mitochondrial Ca(2+)-handling causes the generation of spontaneous activity in pacemaker cells. Possible involvement of protein kinase C (PKC) in the Ca(2+) signaling system was also suggested.

Activity-dependent degeneration of axotomized neuromuscular synapses in WldS mice

PubMed Central

Brown, R.; Hynes-Allen, A.; Swan, A.J.; Dissanayake, K.N.; Gillingwater, T.H.; Ribchester, R.R.

2015-01-01

Activity and disuse of synapses are thought to influence progression of several neurodegenerative diseases in which synaptic degeneration is an early sign. Here we tested whether stimulation or disuse renders neuromuscular synapses more or less vulnerable to degeneration, using axotomy as a robust trigger. We took advantage of the slow synaptic degeneration phenotype of axotomized neuromuscular junctions in flexor digitorum brevis (FDB) and deep lumbrical (DL) muscles of Wallerian degeneration-Slow (WldS) mutant mice. First, we maintained ex vivo FDB and DL nerve-muscle explants at 32 °C for up to 48 h. About 90% of fibers from WldS mice remained innervated, compared with about 36% in wild-type muscles at the 24-h checkpoint. Periodic high-frequency nerve stimulation (100 Hz: 1 s/100 s) reduced synaptic protection in WldS preparations by about 50%. This effect was abolished in reduced Ca2+ solutions. Next, we assayed FDB and DL innervation after 7 days of complete tetrodotoxin (TTX)-block of sciatic nerve conduction in vivo, followed by tibial nerve axotomy. Five days later, only about 9% of motor endplates remained innervated in the paralyzed muscles, compared with about 50% in 5 day-axotomized muscles from saline-control-treated WldS mice with no conditioning nerve block. Finally, we gave mice access to running wheels for up to 4 weeks prior to axotomy. Surprisingly, exercising WldS mice ad libitum for 4 weeks increased about twofold the amount of subsequent axotomy-induced synaptic degeneration. Together, the data suggest that vulnerability of mature neuromuscular synapses to axotomy, a potent neurodegenerative trigger, may be enhanced bimodally, either by disuse or by hyperactivity. PMID:25617654

Hip proprioceptors preferentially modulate reflexes of the leg in human spinal cord injury

PubMed Central

Onushko, Tanya; Hyngstrom, Allison

2013-01-01

Stretch-sensitive afferent feedback from hip muscles has been shown to trigger long-lasting, multijoint reflex responses in people with chronic spinal cord injury (SCI). These reflexes could have important implications for control of leg movements during functional activities, such as walking. Because the control of leg movement relies on reflex regulation at all joints of the limb, we sought to determine whether stretch of hip muscles modulates reflex activity at the knee and ankle and, conversely, whether knee and ankle stretch afferents affect hip-triggered reflexes. A custom-built servomotor apparatus was used to stretch the hip muscles in nine chronic SCI subjects by oscillating the legs about the hip joint bilaterally from 10° of extension to 40° flexion. To test whether stretch-related feedback from the knee or ankle would be affected by hip movement, patellar tendon percussions and Achilles tendon vibration were delivered when the hip was either extending or flexing. Surface electromyograms (EMGs) and joint torques were recorded from both legs. Patellar tendon percussions and Achilles tendon vibration both elicited reflex responses local to the knee or ankle, respectively, and did not influence reflex responses observed at the hip. Rather, the movement direction of the hip modulated the reflex responses local to the joint. The patellar tendon reflex amplitude was larger when the perturbation was delivered during hip extension compared with hip flexion. The response to Achilles vibration was modulated by hip movement, with an increased tonic component during hip flexion compared with extension. These results demonstrate that hip-mediated sensory signals modulate activity in distal muscles of the leg and appear to play a unique role in modulation of spastic muscle activity throughout the leg in SCI. PMID:23615544

ROS Production via P2Y1-PKC-NOX2 Is Triggered by Extracellular ATP after Electrical Stimulation of Skeletal Muscle Cells

PubMed Central

Díaz-Vegas, Alexis; Campos, Cristian A.; Contreras-Ferrat, Ariel; Casas, Mariana; Buvinic, Sonja; Jaimovich, Enrique; Espinosa, Alejandra

2015-01-01

During exercise, skeletal muscle produces reactive oxygen species (ROS) via NADPH oxidase (NOX2) while inducing cellular adaptations associated with contractile activity. The signals involved in this mechanism are still a matter of study. ATP is released from skeletal muscle during electrical stimulation and can autocrinely signal through purinergic receptors; we searched for an influence of this signal in ROS production. The aim of this work was to characterize ROS production induced by electrical stimulation and extracellular ATP. ROS production was measured using two alternative probes; chloromethyl-2,7- dichlorodihydrofluorescein diacetate or electroporation to express the hydrogen peroxide-sensitive protein Hyper. Electrical stimulation (ES) triggered a transient ROS increase in muscle fibers which was mimicked by extracellular ATP and was prevented by both carbenoxolone and suramin; antagonists of pannexin channel and purinergic receptors respectively. In addition, transient ROS increase was prevented by apyrase, an ecto-nucleotidase. MRS2365, a P2Y1 receptor agonist, induced a large signal while UTPyS (P2Y2 agonist) elicited a much smaller signal, similar to the one seen when using ATP plus MRS2179, an antagonist of P2Y1. Protein kinase C (PKC) inhibitors also blocked ES-induced ROS production. Our results indicate that physiological levels of electrical stimulation induce ROS production in skeletal muscle cells through release of extracellular ATP and activation of P2Y1 receptors. Use of selective NOX2 and PKC inhibitors suggests that ROS production induced by ES or extracellular ATP is mediated by NOX2 activated by PKC. PMID:26053483

CAV3 mutations causing exercise intolerance, myalgia and rhabdomyolysis: Expanding the phenotypic spectrum of caveolinopathies.

PubMed

Scalco, Renata Siciliani; Gardiner, Alice R; Pitceathly, Robert D S; Hilton-Jones, David; Schapira, Anthony H; Turner, Chris; Parton, Matt; Desikan, Mahalekshmi; Barresi, Rita; Marsh, Julie; Manzur, Adnan Y; Childs, Anne-Marie; Feng, Lucy; Murphy, Elaine; Lamont, Phillipa J; Ravenscroft, Gianina; Wallefeld, William; Davis, Mark R; Laing, Nigel G; Holton, Janice L; Fialho, Doreen; Bushby, Kate; Hanna, Michael G; Phadke, Rahul; Jungbluth, Heinz; Houlden, Henry; Quinlivan, Ros

2016-08-01

Rhabdomyolysis is often due to a combination of environmental trigger(s) and genetic predisposition; however, the underlying genetic cause remains elusive in many cases. Mutations in CAV3 lead to various neuromuscular phenotypes with partial overlap, including limb girdle muscular dystrophy type 1C (LGMD1C), rippling muscle disease, distal myopathy and isolated hyperCKemia. Here we present a series of eight patients from seven families presenting with exercise intolerance and rhabdomyolysis caused by mutations in CAV3 diagnosed by next generation sequencing (NGS) (n = 6). Symptoms included myalgia (n = 7), exercise intolerance (n = 7) and episodes of rhabdomyolysis (n = 2). Percussion-induced rapid muscle contractions (PIRCs) were seen in five out of six patients examined. A previously reported heterozygous mutation in CAV3 (p.T78M) and three novel variants (p.V14I, p.F41S, p.F54V) were identified. Caveolin-3 immunolabeling in muscle was normal in 3/4 patients; however, immunoblotting showed more than 50% reduction of caveolin-3 in five patients compared with controls. This case series demonstrates that exercise intolerance, myalgia and rhabdomyolysis may be caused by CAV3 mutations and broadens the phenotypic spectrum of caveolinopathies. In our series, immunoblotting was a more sensitive method to detect reduced caveolin-3 levels than immunohistochemistry in skeletal muscle. Patients presenting with muscle pain, exercise intolerance and rhabdomyolysis should be routinely tested for PIRCs as this may be an important clinical clue for caveolinopathies, even in the absence of other "typical" features. The use of NGS may expand current knowledge concerning inherited diseases, and unexpected/atypical phenotypes may be attributed to well-known human disease genes. Copyright © 2016 Elsevier B.V. All rights reserved.

Muscle mitohormesis promotes cellular survival via serine/glycine pathway flux.

PubMed

Ost, Mario; Keipert, Susanne; van Schothorst, Evert M; Donner, Verena; van der Stelt, Inge; Kipp, Anna P; Petzke, Klaus-Jürgen; Jove, Mariona; Pamplona, Reinald; Portero-Otin, Manuel; Keijer, Jaap; Klaus, Susanne

2015-04-01

Recent studies on mouse and human skeletal muscle (SM) demonstrated the important link between mitochondrial function and the cellular metabolic adaptation. To identify key compensatory molecular mechanisms in response to chronic mitochondrial distress, we analyzed mice with ectopic SM respiratory uncoupling in uncoupling protein 1 transgenic (UCP1-TG) mice as model of muscle-specific compromised mitochondrial function. Here we describe a detailed metabolic reprogramming profile associated with mitochondrial perturbations in SM, triggering an increased protein turnover and amino acid metabolism with induced biosynthetic serine/1-carbon/glycine pathway and the longevity-promoting polyamine spermidine as well as the trans-sulfuration pathway. This is related to an induction of NADPH-generating pathways and glutathione metabolism as an adaptive mitohormetic response and defense against increased oxidative stress. Strikingly, consistent muscle retrograde signaling profiles were observed in acute stress states such as muscle cell starvation and lipid overload, muscle regeneration, and heart muscle inflammation, but not in response to exercise. We provide conclusive evidence for a key compensatory stress-signaling network that preserves cellular function, oxidative stress tolerance, and survival during conditions of increased SM mitochondrial distress, a metabolic reprogramming profile so far only demonstrated for cancer cells and heart muscle. © FASEB.

The effects of arm movement on reaction time in patients with latent and active upper trapezius myofascial trigger point.

PubMed

Yassin, Marzieh; Talebian, Saeed; Ebrahimi Takamjani, Ismail; Maroufi, Nader; Ahmadi, Amir; Sarrafzadeh, Javad; Emrani, Anita

2015-01-01

Myofascial pain syndrome is a significant source of mechanical pain. The aim of this study was to investigate the effects of arm movement on reaction time in females with latent and active upper trapezius myofascial trigger point. In this interventional study, a convenience sample of fifteen women with one active MTP, fifteen women with one latent MTP in the upper trapezius, and fifteen normal healthy women were participated. Participants were asked to stand for 10 seconds in an erect standing position. Muscle reaction times were recorded including anterior deltoid (AD), cervical paraspinal (CP) lumbar paraspinal (LP), both of upper trapezius (UT), sternocleidomastoid (SCM) and medial head of gastrocnemius (GcM). Participants were asked to flex their arms in response to a sound stimulus preceded by a warning sound stimulus. Data were analyzed using one-way ANOVA Test. There was significant differences in motor time and reaction time between active and control groups (p< 0.05) except for GcM. There was no significant difference in motor time between active and passive groups except for UT without MTP and SCM (p< 0.05). Also, there were no significant differences in motor times between latent MTP and control groups. Furthermore, there was no significant difference in premotor times between the three groups. The present study shows that patients with active MTP need more time to react to stimulus, but patients with latent MTP are similar to healthy subjects in the reaction time. Patients with active MTP had less compatibility with environmental stimulations, and they responded to a specific stimulation with variability in Surface Electromyography (SEMG).

Neuroscience education in addition to trigger point dry needling for the management of patients with mechanical chronic low back pain: A preliminary clinical trial.

PubMed

Téllez-García, Mario; de-la-Llave-Rincón, Ana I; Salom-Moreno, Jaime; Palacios-Ceña, Maria; Ortega-Santiago, Ricardo; Fernández-de-Las-Peñas, César

2015-07-01

The objective of the current study was to determine the short-term effects of trigger point dry needling (TrP-DN) alone or combined with neuroscience education on pain, disability, kinesiophobia and widespread pressure sensitivity in patients with mechanical low back pain (LBP). Twelve patients with LBP were randomly assigned to receive either TrP-DN (TrP-DN) or TrP-DN plus neuroscience education (TrP-DN + EDU). Pain intensity (Numerical Pain Rating Scale, 0-10), disability (Roland-Morris Disability Questionnaire-RMQ-, Oswestry Low Back Pain Disability Index-ODI), kinesiophobia (Tampa Scale of Kinesiophobia-TSK), and pressure pain thresholds (PPT) over the C5-C6 zygapophyseal joint, transverse process of L3 vertebra, second metacarpal, and tibialis anterior muscle were collected at baseline and 1-week after the intervention. Patients treated with TrP-DN + EDU experienced a significantly greater reduction of kinesiophobia (P = 0.008) and greater increases in PPT over the transverse process of L3 (P = 0.049) than those patients treated only with TrP-DN. Both groups experienced similar decreases in pain, ODI and RMQ, and similar increases in PPT over the C5/C6 joint, second metacarpal, and tibialis anterior after the intervention (all, P > 0.05). The results suggest that TrP-DN was effective for improving pain, disability, kinesiophobia and widespread pressure sensitivity in patients with mechanical LBP at short-term. The inclusion of a neuroscience educational program resulted in a greater improvement in kinesiophobia. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cervical spine dysfunctions in patients with chronic subjective tinnitus.

PubMed

Michiels, Sarah; De Hertogh, Willem; Truijen, Steven; Van de Heyning, Paul

2015-04-01

To assess, characterize, and quantify cervical spine dysfunction in patients with cervicogenic somatic tinnitus (CST) compared to patients suffering from other forms of chronic subjective non-pulsatile tinnitus. Cross-sectional study. Tertiary referral center. Consecutive adult patients suffering from chronic subjective non-pulsatile tinnitus were included. Ménière's disease, middle ear pathology, intracranial pathology, cervical spine surgery, whiplash trauma, temporomandibular dysfunction. Assessment comprises medical history, ENT examination with micro-otoscopy, audiometry, tinnitus assessment, temporomandibular and cervical spine investigation, and brain MRI. Patients were classified into CST and non-CST population. Cervical spine dysfunction was investigated using the Neck Bournemouth Questionnaire (NBQ) and clinical tests of the cervical spine, containing range of motion, pain provocation (adapted Spurling test, AST), and muscle tests (tenderness via trigger points, strength and endurance of deep neck flexors). Between-group analysis was performed. The prevalence of cervical spine dysfunction was described for the total group and for CST and non-CST groups. In total, 87 patients were included, of which 37 (43%) were diagnosed with CST. In comparison with the non-CST group, the CST group demonstrated a significantly higher prevalence of cervical spine dysfunction. In the CST group, 68% had a positive manual rotation test, 47% a positive AST, 49% a positive score on both, and 81% had positive trigger points. In the non-CST group, these percentages were 36, 18, 10, and 50%, respectively. Furthermore, 79% of the CST group had a positive NBQ versus 40% in the non-CST group. Significant differences between the both groups were found for all the aforementioned variables (all p < 0.005). Although a higher prevalence of neck dysfunction was found in the CST group, neck dysfunction is often in non-CST patients.

A myofascial component of pain in knee osteoarthritis.

PubMed

Dor, Adi; Kalichman, Leonid

2017-07-01

Osteoarthritis (OA) is the most common cause of musculoskeletal pain and disability. The knee is the most common site of OA. Numerous studies have shown an inconsistency between patients' reports of pain and their radiographic findings. This inconsistency may be partially explained by the fact that a portion of the pain originates from the myofascial trigger points (MTrPs) located in the surrounding muscles. To assess the role of myofascial pain in OA patients. Critical review. PubMed, Google Scholar, Scopus, and PEDro databases were searched from inception until December 2016 for the following keywords: "myofascial pain", "osteoarthritis", "trigger points", "knee" or any combination of these words. The reference lists of all articles retrieved were searched as well. The current review included two observational studies evaluating the prevalence of MTrPs in OA patients and six interventional studies describing the treatment of myofascial pain in OA patients. Data from two of the interventional studies also included an observational section. The reviewed observational studies offered initial evidence as to the assumption that myofascial pain and the presence of MTrPs may play a role in pain and disability of knee OA. Because of the cross-sectional design of these studies, the causal relationships could not be established. Additional studies are needed to confirm this assumption as well as to clarify if MTrPs are a portion of OA etiology or that OA is the basis for MTrPs formation. Each interventional study elaborated on various myofascial treatment techniques. However, treatment focusing on MTrPs seems to be effective in reducing pain and improving function in OA patients. Due to the heterogeneity in treatment methods and outcome measures, it is difficult to attain a definite conclusion and therefore, additional high-quality randomized controlled trials are warranted. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ethanol Exposure Causes Muscle Degeneration in Zebrafish

PubMed Central

Coffey, Elizabeth C.; Pasquarella, Maggie E.; Goody, Michelle F.

2018-01-01

Alcoholic myopathies are characterized by neuromusculoskeletal symptoms such as compromised movement and weakness. Although these symptoms have been attributed to neurological damage, EtOH may also target skeletal muscle. EtOH exposure during zebrafish primary muscle development or adulthood results in smaller muscle fibers. However, the effects of EtOH exposure on skeletal muscle during the growth period that follows primary muscle development are not well understood. We determined the effects of EtOH exposure on muscle during this phase of development. Strikingly, muscle fibers at this stage are acutely sensitive to EtOH treatment: EtOH induces muscle degeneration. The severity of EtOH-induced muscle damage varies but muscle becomes more refractory to EtOH as muscle develops. NF-kB induction in muscle indicates that EtOH triggers a pro-inflammatory response. EtOH-induced muscle damage is p53-independent. Uptake of Evans blue dye shows that EtOH treatment causes sarcolemmal instability before muscle fiber detachment. Dystrophin-null sapje mutant zebrafish also exhibit sarcolemmal instability. We tested whether Trichostatin A (TSA), which reduces muscle degeneration in sapje mutants, would affect EtOH-treated zebrafish. We found that TSA and EtOH are a lethal combination. EtOH does, however, exacerbate muscle degeneration in sapje mutants. EtOH also disrupts adhesion of muscle fibers to their extracellular matrix at the myotendinous junction: some detached muscle fibers retain beta-Dystroglycan indicating failure of muscle end attachments. Overexpression of Paxillin, which reduces muscle degeneration in zebrafish deficient for beta-Dystroglycan, is not sufficient to rescue degeneration. Taken together, our results suggest that EtOH exposure has pleiotropic deleterious effects on skeletal muscle. PMID:29615556

Triggers and Anatomical Substrates in the Genesis and Perpetuation of Atrial Fibrillation

PubMed Central

Sánchez-Quintana, Damián; López-Mínguez, José Ramón; Pizarro, Gonzalo; Murillo, Margarita; Cabrera, José Angel

2012-01-01

The definition of atrial fibrillation (AF) as a functional electrical disorder does not reflect the significant underlying structural abnormalities. Atrial and Pulmonary Vein (PV) muscle sleeve microstructural remodeling is present, and establishes a vulnerable substrate for AF maintenance. In spite of an incomplete understanding of the anatomo-functional basis for AF, current evidence demonstrates that this arrhythmia usually requires a trigger for initiation and a vulnerable electrophysiological and/or anatomical substrate for maintenance. It is still unclear whether the trigger mechanisms include focal enhanced automaticity, triggered activity and/or micro re-entry from myocardial tissue. Initiation of AF can be favored by both parasympathetic and sympathetic stimulation, which also seem to play a role in maintaining AF. Finally, evolving clinical evidence demonstrates that inflammation is associated with new-onset and recurrent AF through a mechanism that possibly involves cellular degeneration, apoptosis, and subsequent atrial fibrosis. PMID:22920484

Swing- and support-related muscle actions differentially trigger human walk-run and run-walk transitions.

PubMed

Prilutsky, B I; Gregor, R J

2001-07-01

There has been no consistent explanation as to why humans prefer changing their gait from walking to running and from running to walking at increasing and decreasing speeds, respectively. This study examined muscle activation as a possible determinant of these gait transitions. Seven subjects walked and ran on a motor-driven treadmill for 40s at speeds of 55, 70, 85, 100, 115, 130 and 145% of the preferred transition speed. The movements of subjects were videotaped, and surface electromyographic activity was recorded from seven major leg muscles. Resultant moments at the leg joints during the swing phase were calculated. During the swing phase of locomotion at preferred running speeds (115, 130, 145%), swing-related activation of the ankle, knee and hip flexors and peaks of flexion moments were typically lower (P<0.05) during running than during walking. At preferred walking speeds (55, 70, 85%), support-related activation of the ankle and knee extensors was typically lower during stance of walking than during stance of running (P<0.05). These results support the hypothesis that the preferred walk-run transition might be triggered by the increased sense of effort due to the exaggerated swing-related activation of the tibialis anterior, rectus femoris and hamstrings; this increased activation is necessary to meet the higher joint moment demands to move the swing leg during fast walking. The preferred run-walk transition might be similarly triggered by the sense of effort due to the higher support-related activation of the soleus, gastrocnemius and vastii that must generate higher forces during slow running than during walking at the same speed.

SiC/Si diode trigger circuit provides automatic range switching for log amplifier

NASA Technical Reports Server (NTRS)

1967-01-01

SiC/Si diode pair provides automatic range change to extend the operating range of a logarithmic amplifier-conversion circuit and assures stability at or near the range switch-over point. the diode provides hysteresis for a trigger circuit that actuates a relay at the desired range extension point.

The actin-related p41ARC subunit contributes to p21-activated kinase-1 (PAK1)-mediated glucose uptake into skeletal muscle cells.

PubMed

Tunduguru, Ragadeepthi; Zhang, Jing; Aslamy, Arianne; Salunkhe, Vishal A; Brozinick, Joseph T; Elmendorf, Jeffrey S; Thurmond, Debbie C

2017-11-17

Defects in translocation of the glucose transporter GLUT4 are associated with peripheral insulin resistance, preclinical diabetes, and progression to type 2 diabetes. GLUT4 recruitment to the plasma membrane of skeletal muscle cells requires F-actin remodeling. Insulin signaling in muscle requires p21-activated kinase-1 (PAK1), whose downstream signaling triggers actin remodeling, which promotes GLUT4 vesicle translocation and glucose uptake into skeletal muscle cells. Actin remodeling is a cyclic process, and although PAK1 is known to initiate changes to the cortical actin-binding protein cofilin to stimulate the depolymerizing arm of the cycle, how PAK1 might trigger the polymerizing arm of the cycle remains unresolved. Toward this, we investigated whether PAK1 contributes to the mechanisms involving the actin-binding and -polymerizing proteins neural Wiskott-Aldrich syndrome protein (N-WASP), cortactin, and ARP2/3 subunits. We found that the actin-polymerizing ARP2/3 subunit p41ARC is a PAK1 substrate in skeletal muscle cells. Moreover, co-immunoprecipitation experiments revealed that insulin stimulates p41ARC phosphorylation and increases its association with N-WASP coordinately with the associations of N-WASP with cortactin and actin. Importantly, all of these associations were ablated by the PAK inhibitor IPA3, suggesting that PAK1 activation lies upstream of these actin-polymerizing complexes. Using the N-WASP inhibitor wiskostatin, we further demonstrated that N-WASP is required for localized F-actin polymerization, GLUT4 vesicle translocation, and glucose uptake. These results expand the model of insulin-stimulated glucose uptake in skeletal muscle cells by implicating p41ARC as a new component of the insulin-signaling cascade and connecting PAK1 signaling to N-WASP-cortactin-mediated actin polymerization and GLUT4 vesicle translocation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Influence of duty cycle on the time course of muscle fatigue and the onset of neuromuscular compensation during exhaustive dynamic isolated limb exercise

PubMed Central

Sundberg, Christopher W.

2015-01-01

We investigated the influence of altered muscle duty cycle on the performance decrements and neuromuscular responses occurring during constant-load, fatiguing bouts of knee extension exercise. We experimentally altered the durations of the muscularly inactive portion of the limb movement cycle and hypothesized that greater relative durations of inactivity within the same movement task would 1) reduce the rates and extent of muscle performance loss and 2) increase the forces necessary to trigger muscle fatigue. In each condition (duty cycle = 0.6 and 0.3), male subjects [age = 25.9 ± 2.0 yr (SE); mass = 85.4 ± 2.6 kg], completed 9–11 exhaustive bouts of two-legged knee extension exercise, at force outputs that elicited failure between 4 and 290 s. The novel duty cycle manipulation produced two primary results; first, we observed twofold differences in both the extent of muscle performance lost (DC0.6 = 761 ± 35 N vs. DC0.3 = 366 ± 49 N) and the time course of performance loss. For example, exhaustive trials at the midpoint of these force ranges differed in duration by more than 30 s (t0.6 = 36 ± 2.6 vs. t0.3 = 67 ± 4.3 s). Second, both the minimum forces necessary to exceed the peak aerobic capacity and initiate a reliance on anaerobic metabolism, and the forces necessary to elicit compensatory increases in electromyogram activity were 300% greater in the lower vs. higher duty cycle condition. These results indicate that the fatigue-induced compensatory behavior to recruit additional motor units is triggered by a reliance on anaerobic metabolism for ATP resynthesis and is independent of the absolute level or fraction of the maximum force produced by the muscle. PMID:25876654

Applying threshold concepts to conservation management of dryland ecosystems: Case studies on the Colorado Plateau

USGS Publications Warehouse

Bowker, Matthew A.; Miller, Mark E.; Garman, Steven L.; Belote, Travis; Guntenspergen, Glenn R.

2014-01-01

Ecosystems may occupy functionally distinct alternative states, some of which are more or less desirable from a management standpoint. Transitions from state to state are usually associated with a particular trigger or sequence of triggers, such as the addition or subtraction of a disturbance. Transitions are often not linear, rather it is common to see an abrupt transition come about even though the trigger increases only incrementally; these are examples of threshold behaviors. An ideal monitoring program, such as the National Park Service’s Inventory and Monitoring Program, would quantify triggers, and be able to inform managers when measurements of a trigger are approaching a threshold so that management action can avoid an unwanted state transition. Unfortunately, both triggers and the threshold points at which state transitions occur are generally only partially known. Using case studies, we advance a general procedure to help identify triggers and estimate where threshold dynamics may occur. Our procedure is as follows: (1) Operationally define the ecosystem type being considered; we suggest that the ecological site concept of the Natural Resource Conservation Service is a useful system, (2) Using all available a priori knowledge to develop a state-and-transition model (STM), which defines possible ecosystem states, plausible transitions among them and likely triggers, (3) Validate the STM by verifying the existence of its states to the greatest degree possible, (4) Use the STM model to identify transitions and triggers likely to be detectable by a monitoring program, and estimate to the greatest degree possible the value of a measurable indicator of a trigger at the point that a state transition is imminent (tipping point), and values that may indicate when management intervention should be considered (assessment points). We illustrate two different methods for attaining these goals using a data-rich case study in Canyonlands National Park, and a data-poor case study in Wupatki National Monument. In the data-rich case, STMs are validated and revised, and tipping and assessment points are estimated using statistical analysis of data. In the data-poor case, we develop an iterative expert opinion survey approach to validate the degree of confidence in an STM, revise the model, identify lack of confidence in specific model components, and create reasonable first approximations of tipping and assessment points, which can later be refined when more data are available. Our goal should be to develop the best set of models possible given the level of information available to support decisions, which is often not much. The approach presented here offers a flexible means of achieving this goal, and determining specific research areas in need of study.

Contractile properties and sarcoplasmic reticulum calcium content in type I and type II skeletal muscle fibres in active aged humans

PubMed Central

Lamboley, C R; Wyckelsma, V L; Dutka, T L; McKenna, M J; Murphy, R M; Lamb, G D

2015-01-01

This study examined the contractile properties and sarcoplasmic reticulum (SR) Ca2+ content in mechanically skinned vastus lateralis muscle fibres of Old (70 ± 4 years) and Young (22 ± 3 years) humans to investigate whether changes in muscle fibre properties contribute to muscle weakness in old age. In type II fibres of Old subjects, specific force was reduced by ∼17% and Ca2+ sensitivity was also reduced (pCa50 decreased ∼0.05 pCa units) relative to that in Young. S-Glutathionylation of fast troponin I (TnIf) markedly increased Ca2+ sensitivity in type II fibres, but the increase was significantly smaller in Old versus Young (+0.136 and +0.164 pCa unit increases, respectively). Endogenous and maximal SR Ca2+ content were significantly smaller in both type I and type II fibres in Old subjects. In fibres of Young, the SR could be nearly fully depleted of Ca2+ by a combined caffeine and low Mg2+ stimulus, whereas in fibres of Old the amount of non-releasable Ca2+ was significantly increased (by > 12% of endogenous Ca2+ content). Western blotting showed an increased proportion of type I fibres in Old subjects, and increased amounts of calsequestrin-2 and calsequestrin-like protein. The findings suggest that muscle weakness in old age is probably attributable in part to (i) an increased proportion of type I fibres, (ii) a reduction in both maximum specific force and Ca2+ sensitivity in type II fibres, and also a decreased ability of S-glutathionylation of TnIf to counter the fatiguing effects of metabolites on Ca2+ sensitivity, and (iii) a reduction in the amount of releasable SR Ca2+ in both fibre types. Key points Muscle weakness in old age is due in large part to an overall loss of skeletal muscle tissue, but it remains uncertain how much also stems from alterations in the properties of the individual muscle fibres. This study examined the contractile properties and amount of stored intracellular calcium in single muscle fibres of Old (70 ± 4 years) and Young (22 ± 3 years) adults. The maximum level of force production (per unit cross-sectional area) in fast twitch fibres in Old subjects was lower than in Young subjects, and the fibres were also less sensitive to activation by calcium. The amount of calcium stored inside muscle fibres and available to trigger contraction was also lower in both fast- and slow-twitch muscle fibres in the Old subjects. These findings indicate that muscle weakness in old age stems in part from an impaired capacity for force production in the individual muscle fibres. PMID:25809942

Finger muscle attachments for an OpenSim upper-extremity model.

PubMed

Lee, Jong Hwa; Asakawa, Deanna S; Dennerlein, Jack T; Jindrich, Devin L

2015-01-01

We determined muscle attachment points for the index, middle, ring and little fingers in an OpenSim upper-extremity model. Attachment points were selected to match both experimentally measured locations and mechanical function (moment arms). Although experimental measurements of finger muscle attachments have been made, models differ from specimens in many respects such as bone segment ratio, joint kinematics and coordinate system. Likewise, moment arms are not available for all intrinsic finger muscles. Therefore, it was necessary to scale and translate muscle attachments from one experimental or model environment to another while preserving mechanical function. We used a two-step process. First, we estimated muscle function by calculating moment arms for all intrinsic and extrinsic muscles using the partial velocity method. Second, optimization using Simulated Annealing and Hooke-Jeeves algorithms found muscle-tendon paths that minimized root mean square (RMS) differences between experimental and modeled moment arms. The partial velocity method resulted in variance accounted for (VAF) between measured and calculated moment arms of 75.5% on average (range from 48.5% to 99.5%) for intrinsic and extrinsic index finger muscles where measured data were available. RMS error between experimental and optimized values was within one standard deviation (S.D) of measured moment arm (mean RMS error = 1.5 mm < measured S.D = 2.5 mm). Validation of both steps of the technique allowed for estimation of muscle attachment points for muscles whose moment arms have not been measured. Differences between modeled and experimentally measured muscle attachments, averaged over all finger joints, were less than 4.9 mm (within 7.1% of the average length of the muscle-tendon paths). The resulting non-proprietary musculoskeletal model of the human fingers could be useful for many applications, including better understanding of complex multi-touch and gestural movements.

Finger Muscle Attachments for an OpenSim Upper-Extremity Model

PubMed Central

Lee, Jong Hwa; Asakawa, Deanna S.; Dennerlein, Jack T.; Jindrich, Devin L.

2015-01-01

We determined muscle attachment points for the index, middle, ring and little fingers in an OpenSim upper-extremity model. Attachment points were selected to match both experimentally measured locations and mechanical function (moment arms). Although experimental measurements of finger muscle attachments have been made, models differ from specimens in many respects such as bone segment ratio, joint kinematics and coordinate system. Likewise, moment arms are not available for all intrinsic finger muscles. Therefore, it was necessary to scale and translate muscle attachments from one experimental or model environment to another while preserving mechanical function. We used a two-step process. First, we estimated muscle function by calculating moment arms for all intrinsic and extrinsic muscles using the partial velocity method. Second, optimization using Simulated Annealing and Hooke-Jeeves algorithms found muscle-tendon paths that minimized root mean square (RMS) differences between experimental and modeled moment arms. The partial velocity method resulted in variance accounted for (VAF) between measured and calculated moment arms of 75.5% on average (range from 48.5% to 99.5%) for intrinsic and extrinsic index finger muscles where measured data were available. RMS error between experimental and optimized values was within one standard deviation (S.D) of measured moment arm (mean RMS error = 1.5 mm < measured S.D = 2.5 mm). Validation of both steps of the technique allowed for estimation of muscle attachment points for muscles whose moment arms have not been measured. Differences between modeled and experimentally measured muscle attachments, averaged over all finger joints, were less than 4.9 mm (within 7.1% of the average length of the muscle-tendon paths). The resulting non-proprietary musculoskeletal model of the human fingers could be useful for many applications, including better understanding of complex multi-touch and gestural movements. PMID:25853869

Liver kinase B1 inhibits the expression of inflammation-related genes postcontraction in skeletal muscle

PubMed Central

Chen, Ting; Moore, Timothy M.; Ebbert, Mark T. W.; McVey, Natalie L.; Madsen, Steven R.; Hallowell, David M.; Harris, Alexander M.; Char, Robin E.; Mackay, Ryan P.; Hancock, Chad R.; Hansen, Jason M.; Kauwe, John S.

2016-01-01

Skeletal muscle-specific liver kinase B1 (LKB1) knockout mice (skmLKB1-KO) exhibit elevated mitogen-activated protein kinase (MAPK) signaling after treadmill running. MAPK activation is also associated with inflammation-related signaling in skeletal muscle. Since exercise can induce muscle damage, and inflammation is a response triggered by damaged tissue, we therefore hypothesized that LKB1 plays an important role in dampening the inflammatory response to muscle contraction, and that this may be due in part to increased susceptibility to muscle damage with contractions in LKB1-deficient muscle. Here we studied the inflammatory response and muscle damage with in situ muscle contraction or downhill running. After in situ muscle contractions, the phosphorylation of both NF-κB and STAT3 was increased more in skmLKB1-KO vs. wild-type (WT) muscles. Analysis of gene expression via microarray and RT-PCR shows that expression of many inflammation-related genes increased after contraction only in skmLKB1-KO muscles. This was associated with mild skeletal muscle fiber membrane damage in skmLKB1-KO muscles. Gene markers of oxidative stress were also elevated in skmLKB1-KO muscles after contraction. Using the downhill running model, we observed significantly more muscle damage after running in skmLKB1-KO mice, and this was associated with greater phosphorylation of both Jnk and STAT3 and increased expression of SOCS3 and Fos. In conclusion, we have shown that the lack of LKB1 in skeletal muscle leads to an increased inflammatory state in skeletal muscle that is exacerbated by muscle contraction. Increased susceptibility of the muscle to damage may underlie part of this response. PMID:26796753

Dopaminergic modulation of multi-muscle synergies in postural tasks performed by patients with Parkinson’s disease

PubMed Central

Falaki, Ali; Huang, Xuemei; Lewis, Mechelle M.; Latash, Mark L.

2017-01-01

Background Postural instability is one of most disabling motor symptoms in Parkinson’s disease. Indices of multi-muscle synergies are new measurements of postural stability. Objectives We explored the effects of dopamine-replacement drugs on multi-muscle synergies stabilizing center of pressure coordinate and their adjustments prior to a self-triggered perturbation in patients with Parkinson’s disease. We hypothesized that both synergy indices and synergy adjustments would be improved on dopaminergic drugs. Methods Patients at Hoehn-Yahr stages II and III performed whole-body tasks both off- and on-drugs while standing. Muscle modes were identified as factors in the muscle activation space. Synergy indices stabilizing center of pressure in the anterior-posterior direction were quantified in the muscle mode space during a load-release task. Results Dopamine-replacement drugs led to more consistent organization of muscles in stable groups (muscle modes). On-drugs patients showed larger indices of synergies and anticipatory synergy adjustments. In contrast, no medication effects were seen on anticipatory postural adjustments or other performance indices. Conclusions Dopamine-replacement drugs lead to significant changes in characteristics of multi-muscle synergies in Parkinson’s disease. Studies of synergies may provide a biomarker sensitive to problems with postural stability and agility and to efficacy of dopamine-replacement therapy. PMID:28110044

Molecular mechanism of emotional stress-induced and catecholamine-induced heart attack.

PubMed

Ueyama, Takashi; Senba, Emiko; Kasamatsu, Ken; Hano, Takuzo; Yamamoto, Katsuhiro; Nishio, Ichiro; Tsuruo, Yoshihiro; Yoshida, Ken-ichi

2003-01-01

Emotional or physical stress triggers 'tako-tsubo' cardiomyopathy or 'transient left ventricular apical ballooning', but the pathogenesis is unclear. In response to the immobilization stress of rats, a useful model of emotional stress, rapid activation of p44/p42 mitogen-activated protein kinase was observed in the heart, followed by a transient upregulation of immediate early genes in the smooth muscle cells of coronary arteries, the endothelial cells and the myocardium. Heat shock protein 70 was induced in the aortic and coronary arterial smooth muscle cells and in the myocardium. Natriuretic peptide genes were also upregulated in the myocardium. Sequential gene expression can be considered as an adaptive response to emotional stress. Blocking of both alpha-adrenoceptors and beta-adrenoceptors eliminated the upregulation of immediate early genes induced by stress, while alpha-agonists and beta-agonists upregulated immediate early genes in the perfused heart. Activation of alpha-adrenoceptors and beta-adrenoceptors is the primary trigger of emotional stress-induced molecular changes in the heart.

Can surface electromyography improve surgery planning? Electromyographic assessment and intraoperative verification of the nerve bundle entry point location of the gracilis muscle.

PubMed

Romaniszyn, Michal; Walega, Piotr; Nowakowski, Michal; Nowak, Wojciech

2016-06-01

To verify the precision of surface electromyography (sEMG) in locating the innervation zone of the gracilis muscle, by comparing the location of the IZ estimated by means of sEMG with in vivo location of the nerve bundle entry point in patients before graciloplasty procedure due to fecal incontinence. Nine patients who qualified for the graciloplasty procedure underwent sEMG on both gracilis muscle before their operations. During surgery the nerve bundle was identified by means of electrical stimulation. The distance between the proximal attachment and the nerve entry point into the muscle's body was measured. Both measurements (sEMG and in vivo identification) were compared for each subject. On average, the IZ was located 65.5mm from the proximal attachment. The mean difference in location of the innervation zones in each individual was 10±9.7mm, maximal - 30mm, the difference being statistically significant (p=0.017). It was intraoperatively confirmed, that the nerve entered the muscle an average of 62mm from the proximal attachment. The largest difference between the EMG IZ estimation and nerve bundle entry point was 5mm (mean difference 2.8mm, p=0.767). Preoperative surface electromyography of both gracilis muscles is a safe, precise and reliable method of assessing the location of the innervation zones of the gracilis muscles. The asymmetry of the IZ location in left and right muscles may be important in context of technical aspects of the graciloplasty procedure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Twitch analysis as an approach to motor unit activation during electrical stimulation.

PubMed

Heyters, M; Carpentier, A; Duchateau, J; Hainaut, K

1994-12-01

The mechanical twitch in response to increasing electrical stimulus intensity, delivered both over the motor point and motor nerve, was recorded in the first dorsal interosseous (FDI) and the adductor pollicis (AP), and only over the motor point in the soleus (Sol), lateral (LG), and medial (MG) gastrocnemius muscles of human subjects. The relationship between intensity of electrical stimulation (ES) and twitch torque showed a positive linear regression in all muscles. In the FDI and AP the relationship was not significantly different when ES was applied at the motor point or over the motor nerve. At small intensities of activation, ES induced larger twitch torques in the MG and LG, which contain a roughly equal proportion of slow and fast motor units (MUs) compared to the Sol, which is composed mainly of slow type fibres. Moreover, the relationship between ES intensity and twitch time-to-peak is best fitted in all muscles by a power curve that shows a greater twitch time-to-peak range in its initial part for muscles containing a larger proportion of fast MUs (LG, MG) than for muscles mainly composed of slow MUs (Sol). In conclusion, these results induced by ES at the motor point and/or over the motor nerve confirm the concept of a reversed sequence of MU activation, as compared to voluntary contractions, and document this viewpoint in muscles of different function and composition. The reversed sequence of MU activation is more clearly evident during motor point ES.

Oligomeric status of the dihydropyridine receptor in aged skeletal muscle.

PubMed

Ryan, M; Carlson, B M; Ohlendieck, K

2000-10-01

A prominent feature of aging is represented by a decrease in muscle mass and strength. Abnormalities in Ca2+ -regulatory membrane complexes are involved in many muscular disorders. In analogy, we determined potential age-related changes in a key component of excitation-contraction coupling, the dihydropyridine receptor. Immunoblotting of the microsomal fraction from aged rabbit muscle revealed a drastic decline in the voltage-sensing alpha1-subunit of this transverse-tubular receptor, but only marginally altered expression of its auxiliary alpha(2)-subunit and the Na+/K+ -ATPase. A shift to slower fibre type characteristics was indicated by an age-related increase in the slow calsequestrin isoform. Chemical crosslinking analysis showed that the triad receptor complex has a comparable tendency of protein-protein interactions in young and aged muscles. Hence, a reduced expression and not modified oligomerization of the principal dihydropyridine receptor subunit might be involved in triggering impaired triadic signal transduction and abnormal Ca2+ -homeostasis resulting in a progressive functional decline of skeletal muscles. Copyright 2001 Academic Press.

Evidence for ACTN3 as a genetic modifier of Duchenne muscular dystrophy

PubMed Central

Hogarth, Marshall W.; Houweling, Peter J.; Thomas, Kristen C.; Gordish-Dressman, Heather; Bello, Luca; Vishwanathan, V.; Chidambaranathan, S.; Douglas Biggar, W.; McAdam, Laura C.; Mah, Jean K.; Tulinius, Mar; Cnaan, Avital; Morgenroth, Lauren P.; Leshner, Robert; Tesi-Rocha, Carolina; Thangarajh, Mathula; Duong, Tina; Kornberg, Andrew; Ryan, Monique; Nevo, Yoram; Dubrovsky, Alberto; Clemens, Paula R.; Abdel-Hamid, Hoda; Connolly, Anne M.; Pestronk, Alan; Teasley, Jean; Bertorini, Tulio E.; Webster, Richard; Kolski, Hanna; Kuntz, Nancy; Driscoll, Sherilyn; Bodensteiner, John B.; Carlo, Jose; Gorni, Ksenija; Lotze, Timothy; Day, John W.; Karachunski, Peter; Henricson, Erik K.; Abresch, Richard T.; McDonald, Craig M.; Pegoraro, Elena; Hoffman, Eric P.; Head, Stewart I.; North, Kathryn N.

2017-01-01

Duchenne muscular dystrophy (DMD) is characterized by muscle degeneration and progressive weakness. There is considerable inter-patient variability in disease onset and progression, which can confound the results of clinical trials. Here we show that a common null polymorphism (R577X) in ACTN3 results in significantly reduced muscle strength and a longer 10 m walk test time in young, ambulant patients with DMD; both of which are primary outcome measures in clinical trials. We have developed a double knockout mouse model, which also shows reduced muscle strength, but is protected from stretch-induced eccentric damage with age. This suggests that α-actinin-3 deficiency reduces muscle performance at baseline, but ameliorates the progression of dystrophic pathology. Mechanistically, we show that α-actinin-3 deficiency triggers an increase in oxidative muscle metabolism through activation of calcineurin, which likely confers the protective effect. Our studies suggest that ACTN3 R577X genotype is a modifier of clinical phenotype in DMD patients. PMID:28139640

Deficiency in Cardiac Dystrophin Affects the Abundance of the α-/β-Dystroglycan Complex

PubMed Central

2005-01-01

Although Duchenne muscular dystrophy is primarily categorised as a skeletal muscle disease, deficiency in the membrane cytoskeletal protein dystrophin also affects the heart. The central transsarcolemmal linker between the actin membrane cytoskeleton and the extracellular matrix is represented by the dystrophin-associated dystroglycans. Chemical cross-linking analysis revealed no significant differences in the dimeric status of the α-/β-dystroglycan subcomplex in the dystrophic mdx heart as compared to normal cardiac tissue. In analogy to skeletal muscle fibres, heart muscle also exhibited a greatly reduced abundance of both dystroglycans in dystrophin-deficient cells. Immunoblotting demonstrated that the degree of reduction in α-dystroglycan is more pronounced in matured mdx skeletal muscle as contrasted to the mdx heart. The fact that the deficiency in dystrophin triggers a similar pathobiochemical response in both types of muscle suggests that the cardiomyopathic complications observed in x-linked muscular dystrophy might be initiated by the loss of the dystrophin-associated surface glycoprotein complex. PMID:15689636

Voluntary Ambulation by Upper Limb-Triggered HAL® in Patients with Complete Quadri/Paraplegia Due to Chronic Spinal Cord Injury.

PubMed

Shimizu, Yukiyo; Kadone, Hideki; Kubota, Shigeki; Suzuki, Kenji; Abe, Tetsuya; Ueno, Tomoyuki; Soma, Yuichiro; Sankai, Yoshiyuki; Hada, Yasushi; Yamazaki, Masashi

2017-01-01

Patients with complete paraplegia after spinal cord injury (SCI) are unable to stand or walk on their own. Standing exercise decreases the risk of decubitus ulcers, osteoporosis, and joint deformities in patients with SCI. Conventional gait training for complete paraplegia requires excessive upper limb usage for weight bearing and is difficult in cases of complete quadriplegia. The purpose of this study was to describe voluntary ambulation triggered by upper limb activity using the Hybrid Assistive Limb® (HAL) in patients with complete quadri/paraplegia after chronic SCI. Four patients (3 men, 1 woman) were enrolled in this study. The mean patient age ± standard deviation was 37.2 ± 17.8 (range, 20-67) years. Clinical evaluation before intervention revealed the following findings: case 1, neurological level C6, American Spinal Cord Injury Association impairment scale (AIS) grade B; case 2, T6, AIS A; case 3, T10 AIS A; and case 4, T11, AIS A. The HAL intervention consisted of 10 sessions. Each HAL session lasted 60-90 min. The HAL electrodes for hip and knee flexion-extension were placed on the anterior and posterior sides of the upper limbs contralaterally corresponding to each of the lower limbs. Surface electromyography (EMG) was used to evaluate muscle activity of the tensor fascia lata and quadriceps femoris (Quad) in synchronization with a Vicon motion capture system. The modified Ashworth scale (mAs) score was also evaluated before and after each session. All participants completed all 10 sessions. Cases 1, 2, and 3 demonstrated significant decreases in mAs score after the sessions compared to pre-session measurements. In all cases, EMG before the intervention showed no apparent activation in either Quad. However, gait phase dependent activity of the lower limb muscles was seen during voluntarily triggered ambulation driven by upper limb muscle activities. In cases 3 and 4, active contraction in both Quads was observed after intervention. These findings suggest that upper-limb-triggered HAL ambulation is a safe and feasible option for rehabilitation in patients with complete quadri/paraplegia caused by chronic SCI.

Mice expressing T4826I-RYR1 are viable but exhibit sex- and genotype-dependent susceptibility to malignant hyperthermia and muscle damage

PubMed Central

Yuen, Benjamin; Boncompagni, Simona; Feng, Wei; Yang, Tianzhong; Lopez, Jose R.; Matthaei, Klaus I.; Goth, Samuel R.; Protasi, Feliciano; Franzini-Armstrong, Clara; Allen, Paul D.; Pessah, Isaac N.

2012-01-01

Mutation T4825I in the type 1 ryanodine receptor (RYR1T4825I/+) confers human malignant hyperthermia susceptibility (MHS). We report a knock-in mouse line that expresses the isogenetic mutation T4826I. Heterozygous RYR1T4826I/+ (Het) or homozygous RYR1T4826I/T4826I (Hom) mice are fully viable under typical rearing conditions but exhibit genotype- and sex-dependent susceptibility to environmental conditions that trigger MH. Hom mice maintain higher core temperatures than WT in the home cage, have chronically elevated myoplasmic[Ca2+]rest, and present muscle damage in soleus with a strong sex bias. Mice subjected to heat stress in an enclosed 37°C chamber fail to trigger MH regardless of genotype, whereas heat stress at 41°C invariably triggers fulminant MH in Hom, but not Het, mice within 20 min. WT and Het female mice fail to maintain euthermic body temperature when placed atop a bed whose surface is 37°C during halothane anesthesia (1.75%) and have no hyperthermic response, whereas 100% Hom mice of either sex and 17% of the Het males develop fulminant MH. WT mice placed on a 41°C bed maintain body temperature while being administered halothane, and 40% of the Het females and 100% of the Het males develop fulminant MH within 40 min. Myopathic alterations in soleus were apparent by 12 mo, including abnormally distributed and enlarged mitochondria, deeply infolded sarcolemma, and frequent Z-line streaming regions, which were more severe in males. These data demonstrate that an MHS mutation within the S4-S5 cytoplasmic linker of RYR1 confers genotype- and sex-dependent susceptibility to pharmacological and environmental stressors that trigger fulminant MH and promote myopathy.—Yuen, B., Boncompagni, S., Feng, W., Yang, T., Lopez, J. R., Matthaei, K. I., Goth, S. R., Protasi, F., Franzini-Armstrong, C., Allen, P. D., Pessah, I. N. Mice expressing T4826I-RYR1 are viable but exhibit sex- and genotype-dependent susceptibility to malignant hyperthermia and muscle damage. PMID:22131268

Voluntary Ambulation by Upper Limb-Triggered HAL® in Patients with Complete Quadri/Paraplegia Due to Chronic Spinal Cord Injury

PubMed Central

Shimizu, Yukiyo; Kadone, Hideki; Kubota, Shigeki; Suzuki, Kenji; Abe, Tetsuya; Ueno, Tomoyuki; Soma, Yuichiro; Sankai, Yoshiyuki; Hada, Yasushi; Yamazaki, Masashi

2017-01-01

Patients with complete paraplegia after spinal cord injury (SCI) are unable to stand or walk on their own. Standing exercise decreases the risk of decubitus ulcers, osteoporosis, and joint deformities in patients with SCI. Conventional gait training for complete paraplegia requires excessive upper limb usage for weight bearing and is difficult in cases of complete quadriplegia. The purpose of this study was to describe voluntary ambulation triggered by upper limb activity using the Hybrid Assistive Limb® (HAL) in patients with complete quadri/paraplegia after chronic SCI. Four patients (3 men, 1 woman) were enrolled in this study. The mean patient age ± standard deviation was 37.2 ± 17.8 (range, 20–67) years. Clinical evaluation before intervention revealed the following findings: case 1, neurological level C6, American Spinal Cord Injury Association impairment scale (AIS) grade B; case 2, T6, AIS A; case 3, T10 AIS A; and case 4, T11, AIS A. The HAL intervention consisted of 10 sessions. Each HAL session lasted 60–90 min. The HAL electrodes for hip and knee flexion-extension were placed on the anterior and posterior sides of the upper limbs contralaterally corresponding to each of the lower limbs. Surface electromyography (EMG) was used to evaluate muscle activity of the tensor fascia lata and quadriceps femoris (Quad) in synchronization with a Vicon motion capture system. The modified Ashworth scale (mAs) score was also evaluated before and after each session. All participants completed all 10 sessions. Cases 1, 2, and 3 demonstrated significant decreases in mAs score after the sessions compared to pre-session measurements. In all cases, EMG before the intervention showed no apparent activation in either Quad. However, gait phase dependent activity of the lower limb muscles was seen during voluntarily triggered ambulation driven by upper limb muscle activities. In cases 3 and 4, active contraction in both Quads was observed after intervention. These findings suggest that upper-limb-triggered HAL ambulation is a safe and feasible option for rehabilitation in patients with complete quadri/paraplegia caused by chronic SCI. PMID:29209163

Strenuous exercise induces mitochondrial damage in skeletal muscle of old mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Sangho; Kim, Minjung; Lim, Wonchung

Strenuous exercise is known to cause excessive ROS generation and inflammation. However, the mechanisms responsible for the regulation of mitochondrial integrity in the senescent muscle during high-intensity exercise (HE) are not well studied. Here, we show that HE suppresses up-regulation of mitochondrial function despite increase in mitochondrial copy number, following excessive ROS production, proinflammatory cytokines and NFκB activation. Moreover, HE in the old group resulted in the decreasing of both fusion (Mfn2) and fission (Drp1) proteins that may contribute to alteration of mitochondrial morphology. This study suggests that strenuous exercise does not reverse age-related mitochondrial damage and dysfunction by themore » increased ROS and inflammation. - Highlights: • Effect of exercise on mitochondrial function of aged skeletal muscles was studied. • Strenuous exercise triggered excessive ROS production and inflammatory cytokines. • Strenuous exercise suppressed mitochondrial function in senescent muscle.« less

Pharmacological targeting of exercise adaptations in skeletal muscle: Benefits and pitfalls.

PubMed

Weihrauch, Martin; Handschin, Christoph

2018-01-01

Exercise exerts significant effects on the prevention and treatment of many diseases. However, even though some of the key regulators of training adaptation in skeletal muscle have been identified, this biological program is still poorly understood. Accordingly, exercise-based pharmacological interventions for many muscle wasting diseases and also for pathologies that are triggered by a sedentary lifestyle remain scarce. The most efficacious compounds that induce muscle hypertrophy or endurance are hampered by severe side effects and are classified as doping. In contrast, dietary supplements with a higher safety margin exert milder outcomes. In recent years, the design of pharmacological agents that activate the training program, so-called "exercise mimetics", has been proposed, although the feasibility of such an approach is highly debated. In this review, the most recent insights into key regulatory factors and therapeutic approaches aimed at leveraging exercise adaptations are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

Methodology for assessment of low level laser therapy (LLLT) irradiation parameters in muscle inflammation treatment

NASA Astrophysics Data System (ADS)

Mantineo, M.; Pinheiro, J. P.; Morgado, A. M.

2013-11-01

Several studies in human and animals show the clinical effectiveness of low level laser therapy (LLLT) in reducing some types of pain, treating inflammation and wound healing. However, more scientific evidence is required to prove the effectiveness of LLLT since many aspects of the cellular and molecular mechanisms triggered by irradiation of injured tissue with laser remain unknown. Here, we present a methodology that can be used to evaluate the effect of different LLLT irradiation parameters on the treatment of muscle inflammation on animals, through the quantification of four cytokines (TNF-α, IL-1β, IL-2 and IL-6) in systemic blood and histological analysis of muscle tissue. We have used this methodology to assess the effect of LLLT parameters (wavelength, dose, power and type of illumination) in the treatment of inflammation induced in the gastrocnemius muscle of Wistar rats. Results obtained for laser dose evaluation with continuous illumination are presented.

Muscle Atrophy Induced by Mechanical Unloading: Mechanisms and Potential Countermeasures

PubMed Central

Gao, Yunfang; Arfat, Yasir; Wang, Huiping; Goswami, Nandu

2018-01-01

Prolonged periods of skeletal muscle inactivity or mechanical unloading (bed rest, hindlimb unloading, immobilization, spaceflight and reduced step) can result in a significant loss of musculoskeletal mass, size and strength which ultimately lead to muscle atrophy. With advancement in understanding of the molecular and cellular mechanisms involved in disuse skeletal muscle atrophy, several different signaling pathways have been studied to understand their regulatory role in this process. However, substantial gaps exist in our understanding of the regulatory mechanisms involved, as well as their functional significance. This review aims to update the current state of knowledge and the underlying cellular mechanisms related to skeletal muscle loss during a variety of unloading conditions, both in humans and animals. Recent advancements in understanding of cellular and molecular mechanisms, including IGF1-Akt-mTOR, MuRF1/MAFbx, FOXO, and potential triggers of disuse atrophy, such as calcium overload and ROS overproduction, as well as their role in skeletal muscle protein adaptation to disuse is emphasized. We have also elaborated potential therapeutic countermeasures that have shown promising results in preventing and restoring disuse-induced muscle loss. Finally, identified are the key challenges in this field as well as some future prospectives. PMID:29615929

Sarcopenia in patients with advanced liver disease.

PubMed

Ponziani, Francesca Romana; Gasbarrini, Antonio

2017-04-28

Sarcopenia is the loss of muscle mass and function, affecting up to 70% of patients with advanced liver disease. Liver cirrhosis is characterized by an altered glucose metabolism, lipid oxidation, ketogenesis and protein catabolism, leading to the loss of adipose and muscle tissue. The gastrointestinal dysfunction of cirrhotic patients results in inadequate nutrients intake and is responsible for muscle weakness thus limiting physical exercise and perpetuating the reduction of muscle mass. Recently, alterations of hormonal pathways involved in muscle growth, increased intestinal permeability and changes in the gut microbiota composition have been reported in cirrhotic patients. Interestingly, a role of intestinal bacteria in maintaining muscle health has been hypothesized through the translocation of bacteria and bacterial products into the bloodstream triggering the production of muscle wasting-associated cytokines. Sarcopenia is associated with severe outcomes in patients with liver cirrhosis, mostly due to the incidence of disease complications. Furthermore, sarcopenia may represent an important prognostic factor for patients with hepatocellular carcinoma and for those undergoing liver transplantation and can be considered a useful additional tool in the global assessment of patients with advanced liver disease. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Muscle cramps: A comparison of the two-leading hypothesis.

PubMed

Giuriato, Gaia; Pedrinolla, Anna; Federico, Schena; Venturelli, Massimo

2018-05-26

Exercise-Associated Muscle Cramps (EAMC) are a common painful condition of muscle spasms. Despite scientists tried to understand the physiological mechanism that underlies these common phenomena, the etiology is still unclear. From 1900 to nowadays, the scientific world retracted several times the original hypothesis of heat cramps. However, recent literature seems to focus on two potential mechanisms: the dehydration or electrolyte depletion mechanism, and the neuromuscular mechanism. The aim of this review is to examine the recent literature, in terms of physiological mechanisms of EAMC. A comprehensive search was conducted on PubMed and Google Scholar. The following terminology was applied: muscle cramps, neuromuscular hypothesis (or thesis), dehydration hypothesis, Exercise-Associated muscle cramps, nocturnal cramps, muscle spasm, muscle fatigue. From the initial literature of 424 manuscripts, sixty-nine manuscripts were included, analyzed, compared and summarized. Literature analysis indicates that neuromuscular hypothesis may prevails over the initial hypothesis of the dehydration as the trigger event of muscle cramps. New evidence suggests that the action potentials during a muscle cramp are generated in the motoneuron soma, likely accompanied by an imbalance between the rising excitatory drive from the muscle spindles (Ia) and the decreasing inhibitory drive from the Golgi tendon organs. In conclusion, from the latest investigations there seem to be a spinal involvement rather than a peripheral excitation of the motoneurons. Copyright © 2018 Elsevier Ltd. All rights reserved.

Imbalance between pSmad3 and Notch induces CDK inhibitors in old muscle stem cells.

PubMed

Carlson, Morgan E; Hsu, Michael; Conboy, Irina M

2008-07-24

Adult skeletal muscle robustly regenerates throughout an organism's life, but as the muscle ages, its ability to repair diminishes and eventually fails. Previous work suggests that the regenerative potential of muscle stem cells (satellite cells) is not triggered in the old muscle because of a decline in Notch activation, and that it can be rejuvenated by forced local activation of Notch. Here we report that, in addition to the loss of Notch activation, old muscle produces excessive transforming growth factor (TGF)-beta (but not myostatin), which induces unusually high levels of TGF-beta pSmad3 in resident satellite cells and interferes with their regenerative capacity. Importantly, endogenous Notch and pSmad3 antagonize each other in the control of satellite-cell proliferation, such that activation of Notch blocks the TGF-beta-dependent upregulation of the cyclin-dependent kinase (CDK) inhibitors p15, p16, p21 and p27, whereas inhibition of Notch induces them. Furthermore, in muscle stem cells, Notch activity determines the binding of pSmad3 to the promoters of these negative regulators of cell-cycle progression. Attenuation of TGF-beta/pSmad3 in old, injured muscle restores regeneration to satellite cells in vivo. Thus a balance between endogenous pSmad3 and active Notch controls the regenerative competence of muscle stem cells, and deregulation of this balance in the old muscle microniche interferes with regeneration.

Fish proteins as targets of ferrous-catalyzed oxidation: identification of protein carbonyls by fluorescent labeling on two-dimensional gels and MALDI-TOF/TOF mass spectrometry.

PubMed

Pazos, Manuel; da Rocha, Angela Pereira; Roepstorff, Peter; Rogowska-Wrzesinska, Adelina

2011-07-27

Protein oxidation in fish meat is considered to affect negatively the muscle texture. An important source of free radicals taking part in this process is Fenton's reaction dependent on ferrous ions present in the tissue. The aim of this study was to investigate the susceptibility of cod muscle proteins in sarcoplasmic and myofibril fractions to in vitro metal-catalyzed oxidation and to point out protein candidates that might play a major role in the deterioration of fish quality. Extracted control proteins and proteins subjected to free radicals generated by Fe(II)/ascorbate mixture were labeled with fluorescein-5-thiosemicarbazide (FTSC) to tag carbonyl groups and separated by two-dimensional gel electrophoresis. Consecutive visualization of protein carbonyl levels by capturing the FTSC signal and total protein levels by capturing the SyproRuby staining signal allowed us to quantify the relative change in protein carbonyl levels corrected for changes in protein content. Proteins were identified using MALDI-TOF/TOF mass spectrometry and homology-based searches. The results show that freshly extracted cod muscle proteins exhibit a detectable carbonylation background and that the incubation with Fe(II)/ascorbate triggers a further oxidation of both sarcoplasmic and myofibril proteins. Different proteins exhibited various degrees of sensitivity to oxidation processes. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH), nucleoside diphosphate kinase B (NDK), triosephosphate isomerase, phosphoglycerate mutase, lactate dehydrogenase, creatine kinase, and enolase were the sarcoplasmic proteins most vulnerable to ferrous-catalyzed oxidation. Moreover, NDK, phosphoglycerate mutase, and GAPDH were identified in several spots differing by their pI, and those forms showed different susceptibilities to metal-catalyzed oxidation, indicating that post-translational modifications may change the resistance of proteins to oxidative damage. The Fe(II)/ascorbate treatment significantly increased carbonylation of important structural proteins in fish muscle, mainly actin and myosin, and degradation products of those proteins were observed, some of them exhibiting increased carbonylation levels.

Moderate and intense muscular exercises induce marked intramyocellular metabolic acidosis in sickle cell disease mice.

PubMed

Chatel, Benjamin; Messonnier, Laurent A; Hourdé, Christophe; Vilmen, Christophe; Bernard, Monique; Bendahan, David

2017-05-01

Sickle cell disease (SCD) is associated with an impaired oxygen delivery to skeletal muscle that could alter ATP production processes. The present study aimed to determine the effects of sickle hemoglobin (HbS) on muscle pH homeostasis in response to exercise in homozygous (HbSS, n = 9) and heterozygous (HbAS, n = 10) SCD (Townes) mice in comparison to control (HbAA, n = 10) littermates. Magnetic resonance spectroscopy of phosphorus 31 enabled to measure intramuscular pH and phosphocreatine (PCr) concentration during rest-stimulation-recovery protocols at two different intensities. Maximal activity of some enzymes involved in muscle energetics and content of proteins involved in pH regulation were also investigated. HbSS mice presented a more pronounced exercise-induced intramuscular acidosis, whatever the intensity of exercise. Moreover, the depletion of PCr was also exacerbated in HbSS mice in response to intense exercise as compared with both HbAA and HbAS mice ( P < 0.01). While no difference was observed concerning proteins involved in muscle pH regulation, the activity of enolase (a glycolytic enzyme) was higher in both HbSS and HbAS mice as compared with controls ( P < 0.05). Interestingly, HbAS mice presented also metabolic impairments as compared with their control counterparts. This study has identified for the first time an exacerbated exercise-induced intramuscular acidosis in SCD mice. NEW & NOTEWORTHY The main finding of the present study was that the exercise-induced intramuscular acidosis was systematically more pronounced in sickle cell disease (SCD) mice as compared with their control counterparts. This result is important since it has been demonstrated in vitro that acidosis can trigger hemoglobin polymerization. From that point of view, our results tend to support the idea that high-intensity exercise may increase the risk of hemoglobin polymerization in SCD. Copyright © 2017 the American Physiological Society.

A novel mechanism of autophagic cell death in dystrophic muscle regulated by P2RX7 receptor large-pore formation and HSP90.

PubMed

Young, Christopher N J; Sinadinos, Anthony; Lefebvre, Alexis; Chan, Philippe; Arkle, Stephen; Vaudry, David; Gorecki, Dariusz C

2015-01-01

P2RX7 is an ATP-gated ion channel, which can also exhibit an open state with a considerably wider permeation. However, the functional significance of the movement of molecules through the large pore (LP) and the intracellular signaling events involved are not known. Here, analyzing the consequences of P2RX7 activation in primary myoblasts and myotubes from the Dmd(mdx) mouse model of Duchenne muscular dystrophy, we found ATP-induced P2RX7-dependent autophagic flux, leading to CASP3-CASP7-independent cell death. P2RX7-evoked autophagy was triggered by LP formation but not Ca(2+) influx or MAPK1-MAPK3 phosphorylation, 2 canonical P2RX7-evoked signals. Phosphoproteomics, protein expression inference and signaling pathway prediction analysis of P2RX7 signaling mediators pointed to HSPA2 and HSP90 proteins. Indeed, specific HSP90 inhibitors prevented LP formation, LC3-II accumulation, and cell death in myoblasts and myotubes but not in macrophages. Pharmacological blockade or genetic ablation of p2rx7 also proved protective against ATP-induced death of muscle cells, as did inhibition of autophagy with 3-MA. The functional significance of the P2RX7 LP is one of the great unknowns of purinergic signaling. Our data demonstrate a novel outcome--autophagy--and show that molecules entering through the LP can be targeted to phagophores. Moreover, we show that in muscles but not in macrophages, autophagy is needed for the formation of this LP. Given that P2RX7-dependent LP and HSP90 are critically interacting in the ATP-evoked autophagic death of dystrophic muscles, treatments targeting this axis could be of therapeutic benefit in this debilitating and incurable form of muscular dystrophy.

Anatomical association between wrist extensor musculature and topographical pain sensitivity maps of the elbow area.

PubMed

Prados-Frutos, Juan Carlos; Ruiz-Ruiz, Beatriz; De-la-Llave-Rincón, Ana Isabel; Arendt-Nielsen, Lars; Madeleine, Pascal; Fernández-de-Las-Peñas, César

2012-06-01

High-density topographical sensitivity maps have been developed to visualize nonuniformity deep tissue pain sensitivity in, for example, lateral epicondylitis (LE). The aim of this cadaveric study was to determine the anatomical association between the topographical sensitivity maps over the elbow area and wrist extensor musculature. A topographical pressure sensitivity map consisting of 12 points forming a 3 × 4 matrix: 4 points in the superior part, 4 points in the middle, and 4 points in the lower part around the lateral epicondyle was marker on a 50-year embalmed cadaver. Color marker pins were inserted into each point. Pins were removed during the process of dissection, but the small holes created by their removal assured accurate relocation. Progressive dissection revealed that points 1 to 4 (superior line) were placed over the musculotendinous junction and belly of the extensor carpi radialis brevis (ECRB) muscle, points 6 to 8 (middle line) were placed over the musculotendinous junction and belly of the extensor digitorum communis muscle, and points 9 to 12 (inferior line) were located over the musculotendinous junction and belly of the extensor carpi ulnaris muscle. It was also observed that the superficial branch of the radial nerve runs between the belly of the ECRB and extensor digitorum communis muscles. This study confirmed that anatomical location previously assumed supporting the important wrist extensor muscles, particularly the ECRB, in patients with LE as depicted by pressure pain sensitivity maps. This study also suggests a potential role of the superficial branch of the radial nerve in LE. Copyright © 2012 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

Recruitment of motor units in the medial gastrocnemius muscle during human quiet standing: is recruitment intermittent? What triggers recruitment?

PubMed Central

Loram, Ian D.; Muceli, Silvia; Merletti, Roberto; Farina, Dario

2012-01-01

The recruitment and the rate of discharge of motor units are determinants of muscle force. Within a motoneuron pool, recruitment and rate coding of individual motor units might be controlled independently, depending on the circumstances. In this study, we tested whether, during human quiet standing, the force of the medial gastrocnemius (MG) muscle is predominantly controlled by recruitment or rate coding. If MG control during standing was mainly due to recruitment, then we further asked what the trigger mechanism is. Is it determined internally, or is it related to body kinematics? While seven healthy subjects stood quietly, intramuscular electromyograms were recorded from the MG muscle with three pairs of wire electrodes. The number of active motor units and their mean discharge rate were compared for different sway velocities and positions. Motor unit discharges occurred more frequently when the body swayed faster and forward (Pearson R = 0.63; P < 0.0001). This higher likelihood of observing motor unit potentials was explained chiefly by the recruitment of additional units. During forward body shifts, the median number of units detected increased from 3 to 11 (P < 0.0001), whereas the discharge rate changed from 8 ± 1.1 (mean ± SD) to 10 ± 0.9 pulses/s (P = 0.001). Strikingly, motor units did not discharge continuously throughout standing. They were recruited within individual, forward sways and intermittently, with a modal rate of two recruitments per second. This modal rate is consistent with previous circumstantial evidence relating the control of standing to an intrinsic, higher level planning process. PMID:21994258

Recruitment of motor units in the medial gastrocnemius muscle during human quiet standing: is recruitment intermittent? What triggers recruitment?

PubMed

Vieira, Taian M M; Loram, Ian D; Muceli, Silvia; Merletti, Roberto; Farina, Dario

2012-01-01

The recruitment and the rate of discharge of motor units are determinants of muscle force. Within a motoneuron pool, recruitment and rate coding of individual motor units might be controlled independently, depending on the circumstances. In this study, we tested whether, during human quiet standing, the force of the medial gastrocnemius (MG) muscle is predominantly controlled by recruitment or rate coding. If MG control during standing was mainly due to recruitment, then we further asked what the trigger mechanism is. Is it determined internally, or is it related to body kinematics? While seven healthy subjects stood quietly, intramuscular electromyograms were recorded from the MG muscle with three pairs of wire electrodes. The number of active motor units and their mean discharge rate were compared for different sway velocities and positions. Motor unit discharges occurred more frequently when the body swayed faster and forward (Pearson R = 0.63; P < 0.0001). This higher likelihood of observing motor unit potentials was explained chiefly by the recruitment of additional units. During forward body shifts, the median number of units detected increased from 3 to 11 (P < 0.0001), whereas the discharge rate changed from 8 ± 1.1 (mean ± SD) to 10 ± 0.9 pulses/s (P = 0.001). Strikingly, motor units did not discharge continuously throughout standing. They were recruited within individual, forward sways and intermittently, with a modal rate of two recruitments per second. This modal rate is consistent with previous circumstantial evidence relating the control of standing to an intrinsic, higher level planning process.

Recognizing Myofascial Pelvic Pain in the Female Patient with Chronic Pelvic Pain

PubMed Central

Pastore, Elizabeth Anne; Katzman, Wendy B.

2012-01-01

Myofascial pelvic pain (MFPP) is a major component of chronic pelvic pain (CPP) and often is not properly identified by healthcare providers. The hallmark diagnostic indicator of MFPP is myofascial trigger points in the pelvic floor musculature that refer pain to adjacent sites. Effective treatments are available to reduce MFPP, including myofascial trigger point release, PMID:22862153

The effectiveness of manual versus algometer pressure release techniques for treating active myofascial trigger points of the upper trapezius.

PubMed

Abu Taleb, Walaa; Rehan Youssef, Aliaa; Saleh, Amir

2016-10-01

Manual pressure release (MPR) is a popular treatment of trigger points. Yet, treatment response may be influenced by inconsistent application of pressure. Further, it may contribute to increased risk of work-related musculoskeletal disorders of the wrist and hand in therapists. Therefore, this study aimed at introducing a novel method to apply pressure using the algometer and to compare its effectiveness to MPR. Forty-five volunteers with active trigger points of the upper trapezius received algometer pressure release (APR), MPR, or sham ultrasound (US). Pain pressure threshold (PPT) and contralateral active and passive neck side-bending ranges were assessed at baseline and immediately after a single session. Results showed no significant differences in post-treatment PPT between the study groups (p > 0.05). The APR group showed a significant increase in passive side-bending range compared with the two other groups, whereas active range improved in the APR compared with the US group (p < 0.05). Our results show that using algometer to apply pressure release to upper trapezius trigger points is more effective compared with manual release and sham US. Copyright © 2016 Elsevier Ltd. All rights reserved.

Velocity-based planning of rapid elbow movements expands the control scheme of the equilibrium point hypothesis.

PubMed

Suzuki, Masataka; Yamazaki, Yoshihiko

2005-01-01

According to the equilibrium point hypothesis of voluntary motor control, control action of muscles is not explicitly computed, but rather arises as a consequence of interaction between moving equilibrium position, current kinematics and stiffness of the joint. This approach is attractive as it obviates the need to explicitly specify the forces controlling limb movements. However, many debatable aspects of this hypothesis remain in the manner of specification of the equilibrium point trajectory and muscle activation (or its stiffness), which elicits a restoring force toward the planned equilibrium trajectory. In this study, we expanded the framework of this hypothesis by assuming that the control system uses the velocity measure as the origin of subordinate variables scaling descending commands. The velocity command is translated into muscle control inputs by second order pattern generators, which yield reciprocal command and coactivation commands, and create alternating activation of the antagonistic muscles during movement and coactivation in the post-movement phase, respectively. The velocity command is also integrated to give a position command specifying a moving equilibrium point. This model is purely kinematics-dependent, since the descending commands needed to modulate the visco-elasticity of muscles are implicitly given by simple parametric specifications of the velocity command alone. The simulated movements of fast elbow single-joint movements corresponded well with measured data performed over a wide range of movement distances, in terms of both muscle excitations and kinematics. Our proposal on a synthesis for the equilibrium point approach and velocity command, may offer some insights into the control scheme of the single-joint arm movements.

Complex Movement Disorders at Disease Onset in Childhood Narcolepsy with Cataplexy

ERIC Educational Resources Information Center

Plazzi, Giuseppe; Pizza, Fabio; Palaia, Vincenzo; Franceschini, Christian; Poli, Francesca; Moghadam, Keivan K.; Cortelli, Pietro; Nobili, Lino; Bruni, Oliviero; Dauvilliers, Yves; Lin, Ling; Edwards, Mark J.; Mignot, Emmanuel; Bhatia, Kailash P.

2011-01-01

Narcolepsy with cataplexy is characterized by daytime sleepiness, cataplexy (sudden loss of bilateral muscle tone triggered by emotions), sleep paralysis, hypnagogic hallucinations and disturbed nocturnal sleep. Narcolepsy with cataplexy is most often associated with human leucocyte antigen-DQB1*0602 and is caused by the loss of…

Clinical and electrophysiological aspects of tics in children.

PubMed

Safiullina, G I; Safiullina, A A

2015-01-01

Tics are diverse in nature inappropriate movements or vocalizations. They significantly degrade patients' quality of life, lead to social difficulties, and disturbance of learning especially during exacerbations. The prevalence of tics among children ranges from 4% to 24%, thus emphasizing the relevance of the problem. To study clinical and electrophysiological features of tics in children with development of new treatment methods. We conducted a comprehensive clinical and electrophysiological examination of 50 patients with tics, aged 5 to 15 years. The control group consisted of 20 healthy children. The research included a thorough study of the history, neurological examination, manual testing of skeletal muscles, psychological testing. Electrophysiological examination included a review of the functional state of corticospinal tract (CST) by the method of magnetic stimulation (MS), study of polysynaptic reflex excitability (PRE) according to a late component of the blink reflex (BR). Statistical analysis included parametric and nonparametric methods of data processing. All children of the study group showed signs of minimal brain dysfunction (MBD), they had complicated antenatal and postnatal history (trauma, disease, occurring with intoxication). There was a trend towards the increase of MBD signs with worsening of tics. Manual diagnosis in patients identified functional blockade at different levels of the vertebral column, sacroiliac joints, we identified latent myofascial trigger points (MFTP) mainly in the cervical-collar zone, in the area of the paravertebral muscles, periosteal triggers in the area of the sacroiliac joints.The research allowed determining decrease in propagation velocity of excitation (PVE) throughout CST in patients with tics. Correlation analysis revealed a negative correlation between the severity of tics and PVE (r = -0.38; p < 0.001).When studying polysynaptic reflex excitability (PRE) a significant predominance of hyper-excited types of blink reflex (BR) (90% of cases) was revealed. However, in 10% of patients there was a moderate decrease in propagation velocity of excitation (PVE), which allowed us to identify two subgroups of patients with tics: I - low and moderate type of reflex responses; and II - high type of reflex responses. Collation of data of MS and BR revealed a significant decrease of PVE in patients of the subgroup I, which probably reflects a deeper disturbance of the neuro-motor apparatus. The presence of numerous myofascial trigger points (MFTP) in patients of the subgroup I with moderately low polysynaptic reflex excitability (p < 0.05) was characteristic. The data show extraordinary sensitivity of neuromuscular system of children to various physiological and pathological stimuli, occurring in the body in the ontogenesis or diseases, and multifactorial origin of the pain syndrome in tics.The results suggest that one of the main mechanisms of development of pathological process is dysfunction of descending inhibitory control. However, further clarification of the type of polysynaptic reflex excitability in a certain patient is needed, that will allow to develop individualized approach to the choice of therapeutic interventions.

Ultrasound-Based Detection of Low Muscle Mass for Diagnosis of Sarcopenia in Older Adults.

PubMed

Minetto, Marco A; Caresio, Cristina; Menapace, Tommaso; Hajdarevic, Arnel; Marchini, Andrea; Molinari, Filippo; Maffiuletti, Nicola A

2016-05-01

To establish muscle-specific cut-off values for ultrasound-based detection of low muscle mass, and to assess its prevalence in a population of frail older subjects when applying the cut-points of different muscles and those of different sarcopenic indices. Cross-sectional study. Geriatric outpatient clinic and clinical research laboratory. A total of 44 older adults (30 women and 14 men, mean age 82 years, range 67-93 years) and 60 younger individuals (30 women and 30 men, mean age 26 years, range 20-36 years) participated. Body composition and thickness of 4 lower limb muscles (rectus femoris, vastus lateralis, tibialis anterior, medial gastrocnemius) were respectively assessed by bioelectrical impedance analysis (BIA) and ultrasonography. Site-specific cut-points for ultrasound-based assessment of low muscle mass (muscle thickness values 2 standard deviations below the gender-specific means of our sample of younger subjects) and comparative prevalence rates of low muscle mass. The following site-specific cut-points for muscle thickness were identified: rectus femoris: 20 mm in men and 16 mm in women; vastus lateralis: 17 mm in men and 15 mm in women; tibialis anterior: 23 mm in men and 22 mm in women; and medial gastrocnemius: 13 mm in both men and women. The prevalence of low muscle mass in older adults was highly dependent on the muscle being investigated; it varied from 86% for thigh muscles to 30% for leg muscles. Moreover, the prevalence of low muscle mass was highly dependent on the applied diagnostic criterion and on the adopted cut-off value; it ranged from 2% to 75% for different BIA-derived criteria. We suggest that muscle ultrasonography provides physiatrists with a practical and accurate tool for identifying individuals with low muscle mass. However, the usability of cut-off values established in our group of healthy younger subjects of white ethnicity to identify low muscle mass in older individuals of different ethnic groups remains to be demonstrated in future studies. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Anatomical Regional Targeted (ART) BOTOX Injection Technique: A Novel Paradigm for Migraines and Chronic Headaches

PubMed Central

Sanniec, Kyle; Pezeshk, Ronnie; Chung, Michael

2016-01-01

Summary: Migraine headaches are a debilitating disease that causes significant socioeconomic problems. One of the speculated etiologies of the generation of migraines is peripheral nerve irritation at different trigger points. The use of Onabotulinum toxin A (BOTOX), although initially a novel approach, has now been determined to be a valid treatment for chronic headaches and migraines as described in the Phase III Research Evaluating Migraine Prophylaxis Therapy trials that prompted the approval by the Food and Drug Administration for treatment of chronic migraines. The injection paradigm established by this trial was one of a broad injection pattern across large muscle groups that did not always correspond to the anatomical locations of nerves. The senior author developed the Anatomical Regional Targeted BOTOX injection paradigm as an alternative to the current injection model. This technique targets both the anatomical location of nerves known to have causal effects with migraines and the region where the pain localizes, to provide relief across a wide distribution of the peripheral nerve. This article serves as a guide to the Anatomical Regional Targeted injection technique, which, to our knowledge, is the first comprehensive BOTOX injection paradigm described in the literature for treatment of migraines that targets nerves and nerve areas rather than purely muscle groups. This technique is based on the most up-to-date anatomical and scientific studies and large-volume migraine surgery experience. PMID:28293532

Botulinum toxin for pain.

PubMed

Casale, Roberto; Tugnoli, Valeria

2008-01-01

Botulinum toxin (BTX) injection is being increasingly used 'off label' in the management of chronic pain. Data support the hypothesis of a direct analgesic effect of BTX, different to that exerted on muscle. Although the pain-reducing effect of BTX is mainly due to its ability to block acetylcholine release at the synapse, other effects on the nervous system are also thought to be involved. BTX affects cholinergic transmission in both the somatic and the autonomic nervous systems. Proposed mechanisms of action of BTX for pain relief of trigger points, muscular spasms, fibromyalgia and myofascial pain include direct action on muscle and indirect effects via action at the neuromuscular junction. Invitro and invivo data have shown that BTX has specific antinociceptive activity relating to its effects on inflammation, axonal transport, ganglion inhibition, and spinal and suprasegmental level inhibition. Our review of the mechanisms of action, efficacy, administration techniques and therapeutic dosage of BTX for the management of chronic pain in a variety of conditions shows that although muscular tone and movement disorders remain the most important therapeutic applications for BTX, research suggests that BTX can also provide benefits related to effects on cholinergic control of the vascular system, autonomic function, and cholinergic control of nociceptive and antinociceptive systems. Furthermore, it appears that BTX may influence the peripheral and central nervous systems. The therapeutic potential of BTX depends mainly on the ability to deliver the toxin to the target structures, cholinergic or otherwise. Evidence suggests that BTX can be administered at standard dosages in pain disorders, where the objective is alteration of muscle tone. For conditions requiring an analgesic effect, the optimal therapeutic dosage of BTX remains to be defined.

Treatment of whiplash associated neck pain [corrected] with botulinum toxin-A: a pilot study.

PubMed

Freund, B J; Schwartz, M

2000-02-01

Up to 87% of patients with whiplash associated disorder (WAD) have some degree of muscle spasm that is contributory to both pain and dysfunction. Botulinum toxin A (BTX-A) produces prolonged muscle relaxation that is dose-dependent and can be easily targeted to affected muscles. BTX-A therapy may be an effective form of therapy offering an alternative or adjunct to conventional modalities. We investigated BTX-A as therapy in patients with WAD. This randomized, double blind, placebo controlled study compares outcome measures in 26 patients with chronic neck pain (WAD-II chronic) subsequent to a motor vehicle accident. One-half of the patients received 100 units BTX-A, diluted in 1 ml saline, while the other half received just saline (1 ml). Five trigger points received 0.2 ml each of injectant via a 30 gauge needle. Outcome measures included total subjective neck, shoulder, and head pain based on visual analog scales; objective total range of neck motion (ROM), and the Vernon-Mior subjective function index. Followup assessments were carried out at 2 and 4 weeks post-treatment. Fourteen subjects receiving BTX-A and 12 receiving saline completed the study. The treatment group showed a trend toward improvement in ROM and reduction in pain at 2 weeks post-injection. At 4 weeks post-injection the treatment group was significantly improved from preinjection levels (p < 0.01). The placebo group showed no statistically significant changes at any post-treatment time. The Vernon-Mior scale revealed a trend to improvement for both groups. BTX-A treatment of subjects with chronic WAD II neck pain resulted in a significant (p < 0.01) improvement in ROM and subjective pain compared to a placebo group, but only a trend to improvement in subjective functioning.

Adult and juvenile dermatomyositis: are the distinct clinical features explained by our current understanding of serological subgroups and pathogenic mechanisms?

PubMed Central

2013-01-01

Adult and juvenile dermatomyositis share the hallmark features of pathognomic skin rash and muscle inflammation, but are heterogeneous disorders with a range of additional disease features and complications. The frequency of important clinical features such as calcinosis, interstitial lung disease and malignancy varies markedly between adult and juvenile disease. These differences may reflect different disease triggers between children and adults, but whilst various viral and other environmental triggers have been implicated, results are so far conflicting. Myositis-specific autoantibodies can be detected in both adults and children with idiopathic inflammatory myopathies. They are associated with specific disease phenotypes and complications, and divide patients into clinically homogenous subgroups. Interestingly, whilst the same autoantibodies are found in both adults and children, the disease features remain different within autoantibody subgroups, particularly with regard to life-threatening disease associations, such as malignancy and rapidly progressive interstitial lung disease. Our understanding of the mechanisms that underlie these differences is limited by a lack of studies directly comparing adults and children. Dermatomyositis is an autoimmune disease, which is believed to develop as a result of an environmental trigger in a genetically predisposed individual. Age-specific host immune responses and muscle physiology may be additional complicating factors that have significant impact on disease presentation. Further study into this area may produce new insights into disease pathogenesis. PMID:23566358

Complement activation promotes muscle inflammation during modified muscle use

NASA Technical Reports Server (NTRS)

Frenette, J.; Cai, B.; Tidball, J. G.

2000-01-01

Modified muscle use can result in muscle inflammation that is triggered by unidentified events. In the present investigation, we tested whether the activation of the complement system is a component of muscle inflammation that results from changes in muscle loading. Modified rat hindlimb muscle loading was achieved by removing weight-bearing from the hindlimbs for 10 days followed by reloading through normal ambulation. Experimental animals were injected with the recombinant, soluble complement receptor sCR1 to inhibit complement activation. Assays for complement C4 or factor B in sera showed that sCR1 produced large reductions in the capacity for activation of the complement system through both the classical and alternative pathways. Analysis of complement C4 concentration in serum in untreated animals showed that the classical pathway was activated during the first 2 hours of reloading. Analysis of factor B concentration in untreated animals showed activation of the alternative pathway at 6 hours of reloading. Administration of sCR1 significantly attenuated the invasion of neutrophils (-49%) and ED1(+) macrophages (-52%) that occurred in nontreated animals after 6 hours of reloading. The presence of sCR1 also reduced significantly the degree of edema by 22% as compared to untreated animals. Together, these data show that increased muscle loading activated the complement system which then briefly contributes to the early recruitment of inflammatory cells during modified muscle loading.

Sirtuin 1 Mediates the Actions of Peroxisome Proliferator-Activated Receptor δ on the Oxidized Low-Density Lipoprotein-Triggered Migration and Proliferation of Vascular Smooth Muscle Cells.

PubMed

Hwang, Jung Seok; Ham, Sun Ah; Yoo, Taesik; Lee, Won Jin; Paek, Kyung Shin; Lee, Chi-Ho; Seo, Han Geuk

2016-11-01

Peroxisome proliferator-activated receptor δ (PPARδ) has been implicated in vascular pathophysiology. However, its functions in atherogenic changes of the vascular wall have not been fully elucidated. PPARδ activated by GW501516 (2-[2-methyl-4-[[4-methyl-2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-5-yl]methylsulfanyl]phenoxy]acetic acid) significantly inhibited the migration and proliferation of vascular smooth muscle cells (VSMCs) triggered by oxidized low-density lipoprotein (oxLDL). These GW501516-mediated effects were significantly reversed by PPARδ-targeting small-interfering RNA (siRNA), indicating that PPARδ is involved in the action of GW501516. The antiproliferative effect of GW501516 was directly linked to cell cycle arrest at the G 0 /G 1 to S phase transition, which was followed by the down-regulation of cyclin-dependent kinase 4 along with increased levels of p21 and p53. In VSMCs treated with GW501516, the expression of sirtuin 1 (SIRT1) mRNA and protein was time-dependently increased. This GW501516-mediated up-regulation of SIRT1 expression was also demonstrated even in the presence of oxLDL. In addition, GW501516-dependent inhibition of oxLDL-triggered migration and proliferation of VSMCs was almost completely abolished in the presence of SIRT1-targeting siRNA. These effects of GW501516 on oxLDL-triggered phenotypic changes of VSMCs were also demonstrated via activation or inhibition of SIRT1 activity by resveratrol or sirtinol, respectively. Finally, gain or loss of SIRT1 function imitated the action of PPARδ on oxLDL-triggered migration and proliferation of VSMCs. Taken together, these observations indicate that PPARδ-dependent up-regulation of SIRT1 contributes to the antiatherogenic activities of PPARδ by suppressing the migration and proliferation of VSMCs linked to vascular diseases such as restenosis and atherosclerosis. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Hypoxia inducible factor 1 links fast-patterned muscle activity and fast muscle phenotype in rats.

PubMed

Lunde, Ida G; Anton, Siobhan L; Bruusgaard, Jo C; Rana, Zaheer A; Ellefsen, Stian; Gundersen, Kristian

2011-03-15

Exercise influences muscle phenotype by the specific pattern of action potentials delivered to the muscle, triggering intracellular signalling pathways. PO2 can be reduced by an order of magnitude in working muscle. In humans, carriers of a hyperactive polymorphism of the transcription factor hypoxia inducible factor 1α (HIF-1α) have 50% more fast fibres, and this polymorphism is prevalent among strength athletes. We have investigated the putative role of HIF-1α in mediating activity changes in muscle.When rat muscles were stimulated with short high frequency bursts of action potentials known to induce a fast muscle phenotype, HIF-1α increased by about 80%. In contrast, a pattern consisting of long low frequency trains known to make fast muscles slow reduced the HIF-1α level of the fast extensor digitorum longus (EDL) muscle by 44%. Nuclear protein extracts from normal EDL contained 2.3-fold more HIF-1α and 4-fold more HIF-1β than the slow soleus muscle, while von-Hippel-Lindau protein was 4.8-fold higher in slow muscles. mRNA displayed a reciprocal pattern; thus FIH-1 mRNA was almost 2-fold higher in fast muscle, while the HIF-1α level was half, and consequently protein/mRNA ratio for HIF-1α was more than 4-fold higher in the fast muscle, suggesting that HIF-1α is strongly suppressed post-transcriptionally in slow muscles.When HIF-1α was overexpressed for 14 days after somatic gene transfer in adult rats, a slow-to-fast transformation was observed, encompassing an increase in fibre cross sectional area, oxidative enzyme activity and myosin heavy chain. The latter was shown to be regulated at the mRNA level in C2C12 myotubes.

[Spasm of accommodation].

PubMed

Lindberg, Laura

2014-01-01

Spasm of accommodation refers to prolonged contraction of the ciliary muscle, most commonly causing pseudomyopia to varying degrees in both eyes by keeping the lens in a state of short sightedness. It may also be manifested as inability to allow the adaptation spasticity prevailing in the ciliary muscle relax without measurable myopia. As a rule, this is a functional ailment triggered by prolonged near work and stress. The most common symptoms include blurring of distance vision, varying visual acuity as well as pains in the orbital region and the head, progressing into a chronic state. Cycloplegic eye drops are used as the treatment.

p21‐Activated kinase (Pak) regulates airway smooth muscle contraction by regulating paxillin complexes that mediate actin polymerization

PubMed Central

Zhang, Wenwu; Huang, Youliang

2016-01-01

Key points In airway smooth muscle, tension development caused by a contractile stimulus requires phosphorylation of the 20 kDa myosin light chain (MLC), which activates crossbridge cycling and the polymerization of a pool of submembraneous actin.The p21‐activated kinases (Paks) can regulate the contractility of smooth muscle and non‐muscle cells, and there is evidence that this occurs through the regulation of MLC phosphorylation.We show that Pak has no effect on MLC phosphorylation during the contraction of airway smooth muscle, and that it regulates contraction by mediating actin polymerization.We find that Pak phosphorylates the adhesion junction protein, paxillin, on Ser273, which promotes the formation of a signalling complex that activates the small GTPase, cdc42, and the actin polymerization catalyst, neuronal Wiskott–Aldrich syndrome protein (N‐WASP).These studies demonstrate a novel role for Pak in regulating the contractility of smooth muscle by regulating actin polymerization. Abstract The p21‐activated kinases (Pak) can regulate contractility in smooth muscle and other cell and tissue types, but the mechanisms by which Paks regulate cell contractility are unclear. In airway smooth muscle, stimulus‐induced contraction requires phosphorylation of the 20 kDa light chain of myosin, which activates crossbridge cycling, as well as the polymerization of a small pool of actin. The role of Pak in airway smooth muscle contraction was evaluated by inhibiting acetylcholine (ACh)‐induced Pak activation through the expression of a kinase inactive mutant, Pak1 K299R, or by treating tissues with the Pak inhibitor, IPA3. Pak inhibition suppressed actin polymerization and contraction in response to ACh, but it did not affect myosin light chain phosphorylation. Pak activation induced paxillin phosphorylation on Ser273; the paxillin mutant, paxillin S273A, inhibited paxillin Ser273 phosphorylation and inhibited actin polymerization and contraction. Immunoprecipitation analysis of tissue extracts and proximity ligation assays in dissociated cells showed that Pak activation and paxillin Ser273 phosphorylation triggered the formation of an adhesion junction signalling complex with paxillin that included G‐protein‐coupled receptor kinase‐interacting protein (GIT1) and the cdc42 guanine exchange factor, βPIX (Pak interactive exchange factor). Assembly of the Pak–GIT1–βPIX–paxillin complex was necessary for cdc42 and neuronal Wiskott–Aldrich syndrome protein (N‐WASP) activation, actin polymerization and contraction in response to ACh. RhoA activation was also required for the recruitment of Pak to adhesion junctions, Pak activation, paxillin Ser273 phosphorylation and paxillin complex assembly. These studies demonstrate a novel role for Pak in the regulation of N‐WASP activation, actin dynamics and cell contractility. PMID:27038336

Further considerations on in vitro skeletal muscle cell death

PubMed Central

Battistelli, Michela; Salucci, Sara; Burattini, Sabrina; Falcieri, Elisabetta

2013-01-01

Summary The present review discusses the apoptotic behavior induced by chemical and physical triggers in C2C12 skeletal muscle cells, comparing myoblast to myotube sensitivity, and investigating it by means of morphological, biochemical and cytofluorimetric analyses. After all treatments, myotubes, differently from myoblasts, showed a poor sensitivity to cell death. Intriguingly, in cells exposed to staurosporine, etoposide and UVB radiation, apoptotic and normal nuclei within the same fibercould be revealed. The presence of nuclear-dependent “territorial” death domains in the syncytium could explain a delayed cell death of myotubes compared to mononucleated cells. Moreover, autophagic granules abundantly appeared in myotubes after each treatment. Autophagy could protect muscle cell integrity against chemical and physical stimuli, making C2C12 myotubes, more resistant to cell death induction. PMID:24596689

Task-specific motor performance and musculoskeletal response in self-classified right handers.

PubMed

Kumar, Sameer; Mandal, Manas K

2003-11-01

We examined the difference between the left and right hand motor performance (in terms of erg produced) of self-classified right handers (15 men, 15 women) for power (task involving muscle force) and skilled (task involving precision and eye hand coordination) tasks. Musculoskeletal response during task performance was measured by electromyogram to test the hypothesis that performance with the nondominant hand would trigger more generalized muscle tension. The difference between the left and right hand performance of men was nonsignificant for power task; for women, right hand performance was significantly superior than left for such task. Men excelled in power and women excelled in skilled tasks relative to their counterparts. Generalized muscle tension was significantly more during the left than the right hand performance for power but not for skilled tasks.

Skeletal muscle Kv7 (KCNQ) channels in myoblast differentiation and proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roura-Ferrer, Meritxell; Sole, Laura; Martinez-Marmol, Ramon

Voltage-dependent K{sup +} channels (Kv) are involved in myocyte proliferation and differentiation by triggering changes in membrane potential and regulating cell volume. Since Kv7 channels may participate in these events, the purpose of this study was to investigate whether skeletal muscle Kv7.1 and Kv7.5 were involved during proliferation and myogenesis. Here we report that, while myotube formation did not regulate Kv7 channels, Kv7.5 was up-regulated during cell cycle progression. Although, Kv7.1 mRNA also increased during the G{sub 1}-phase, pharmacological evidence mainly involves Kv7.5 in myoblast growth. Our results indicate that the cell cycle-dependent expression of Kv7.5 is involved in skeletalmore » muscle cell proliferation.« less

Ezrin enhances line tension along transcellular tunnel edges via NMIIa driven actomyosin cable formation

NASA Astrophysics Data System (ADS)

Stefani, Caroline; Gonzalez-Rodriguez, David; Senju, Yosuke; Doye, Anne; Efimova, Nadia; Janel, Sébastien; Lipuma, Justine; Tsai, Meng Chen; Hamaoui, Daniel; Maddugoda, Madhavi P.; Cochet-Escartin, Olivier; Prévost, Coline; Lafont, Frank; Svitkina, Tatyana; Lappalainen, Pekka; Bassereau, Patricia; Lemichez, Emmanuel

2017-06-01

Transendothelial cell macroaperture (TEM) tunnels control endothelium barrier function and are triggered by several toxins from pathogenic bacteria that provoke vascular leakage. Cellular dewetting theory predicted that a line tension of uncharacterized origin works at TEM boundaries to limit their widening. Here, by conducting high-resolution microscopy approaches we unveil the presence of an actomyosin cable encircling TEMs. We develop a theoretical cellular dewetting framework to interpret TEM physical parameters that are quantitatively determined by laser ablation experiments. This establishes the critical role of ezrin and non-muscle myosin II (NMII) in the progressive implementation of line tension. Mechanistically, fluorescence-recovery-after-photobleaching experiments point for the upstream role of ezrin in stabilizing actin filaments at the edges of TEMs, thereby favouring their crosslinking by NMIIa. Collectively, our findings ascribe to ezrin and NMIIa a critical function of enhancing line tension at the cell boundary surrounding the TEMs by promoting the formation of an actomyosin ring.

Ezrin enhances line tension along transcellular tunnel edges via NMIIa driven actomyosin cable formation

PubMed Central

Stefani, Caroline; Gonzalez-Rodriguez, David; Senju, Yosuke; Doye, Anne; Efimova, Nadia; Janel, Sébastien; Lipuma, Justine; Tsai, Meng Chen; Hamaoui, Daniel; Maddugoda, Madhavi P.; Cochet-Escartin, Olivier; Prévost, Coline; Lafont, Frank; Svitkina, Tatyana; Lappalainen, Pekka; Bassereau, Patricia; Lemichez, Emmanuel

2017-01-01

Transendothelial cell macroaperture (TEM) tunnels control endothelium barrier function and are triggered by several toxins from pathogenic bacteria that provoke vascular leakage. Cellular dewetting theory predicted that a line tension of uncharacterized origin works at TEM boundaries to limit their widening. Here, by conducting high-resolution microscopy approaches we unveil the presence of an actomyosin cable encircling TEMs. We develop a theoretical cellular dewetting framework to interpret TEM physical parameters that are quantitatively determined by laser ablation experiments. This establishes the critical role of ezrin and non-muscle myosin II (NMII) in the progressive implementation of line tension. Mechanistically, fluorescence-recovery-after-photobleaching experiments point for the upstream role of ezrin in stabilizing actin filaments at the edges of TEMs, thereby favouring their crosslinking by NMIIa. Collectively, our findings ascribe to ezrin and NMIIa a critical function of enhancing line tension at the cell boundary surrounding the TEMs by promoting the formation of an actomyosin ring. PMID:28643776

Ezrin enhances line tension along transcellular tunnel edges via NMIIa driven actomyosin cable formation.

PubMed

Stefani, Caroline; Gonzalez-Rodriguez, David; Senju, Yosuke; Doye, Anne; Efimova, Nadia; Janel, Sébastien; Lipuma, Justine; Tsai, Meng Chen; Hamaoui, Daniel; Maddugoda, Madhavi P; Cochet-Escartin, Olivier; Prévost, Coline; Lafont, Frank; Svitkina, Tatyana; Lappalainen, Pekka; Bassereau, Patricia; Lemichez, Emmanuel

2017-06-23

Transendothelial cell macroaperture (TEM) tunnels control endothelium barrier function and are triggered by several toxins from pathogenic bacteria that provoke vascular leakage. Cellular dewetting theory predicted that a line tension of uncharacterized origin works at TEM boundaries to limit their widening. Here, by conducting high-resolution microscopy approaches we unveil the presence of an actomyosin cable encircling TEMs. We develop a theoretical cellular dewetting framework to interpret TEM physical parameters that are quantitatively determined by laser ablation experiments. This establishes the critical role of ezrin and non-muscle myosin II (NMII) in the progressive implementation of line tension. Mechanistically, fluorescence-recovery-after-photobleaching experiments point for the upstream role of ezrin in stabilizing actin filaments at the edges of TEMs, thereby favouring their crosslinking by NMIIa. Collectively, our findings ascribe to ezrin and NMIIa a critical function of enhancing line tension at the cell boundary surrounding the TEMs by promoting the formation of an actomyosin ring.

Using Contingent Reinforcement to Augment Muscle Activation After Perinatal Brachial Plexus Injury: A Pilot Study.

PubMed

Duff, S V; Sargent, B; Kutch, J J; Berggren, J; Leiby, B E; Fetters, L

2017-10-20

Examine the feasibility of increasing muscle activation with electromyographically (EMG)-triggered musical-video as reinforcement for children with perinatal brachial plexus injury (PBPI). Six children with PBPI (9.3 ± 6.3 months; 5 female, 1 male) and 13 typically developing (TD) controls (7.8 ± 3.5 months; 4 female, 9 males) participated. The left arm was affected in 5/6 children with PBPI. We recorded the integral (Vs) of biceps activation with surface EMG during two conditions per arm in one session: (1) 100 second (s) baseline without reinforcement and (2) 300 s reinforcement (musical-video triggered to play with biceps activation above threshold [V]). We examined the relation between the mean integral with reinforcement and hand preference. Mean biceps activation significantly increased from baseline in the affected arm of the group with PBPI by the 2nd (p < .008) and 3rd (p < .0004) 100 s intervals of reinforcement. Six of 6 children with PBPI and 12/13 TD controls increased activation in at least one arm. A lower integral was linked with hand preference for the unaffected right side in the PBPI group. This study supports contingent reinforcement as a feasible method to increase muscle activation. Future work will examine training dose and intensity to increase arm function.

Joint cross-correlation analysis reveals complex, time-dependent functional relationship between cortical neurons and arm electromyograms

PubMed Central

Zhuang, Katie Z.; Lebedev, Mikhail A.

2014-01-01

Correlation between cortical activity and electromyographic (EMG) activity of limb muscles has long been a subject of neurophysiological studies, especially in terms of corticospinal connectivity. Interest in this issue has recently increased due to the development of brain-machine interfaces with output signals that mimic muscle force. For this study, three monkeys were implanted with multielectrode arrays in multiple cortical areas. One monkey performed self-timed touch pad presses, whereas the other two executed arm reaching movements. We analyzed the dynamic relationship between cortical neuronal activity and arm EMGs using a joint cross-correlation (JCC) analysis that evaluated trial-by-trial correlation as a function of time intervals within a trial. JCCs revealed transient correlations between the EMGs of multiple muscles and neural activity in motor, premotor and somatosensory cortical areas. Matching results were obtained using spike-triggered averages corrected by subtracting trial-shuffled data. Compared with spike-triggered averages, JCCs more readily revealed dynamic changes in cortico-EMG correlations. JCCs showed that correlation peaks often sharpened around movement times and broadened during delay intervals. Furthermore, JCC patterns were directionally selective for the arm-reaching task. We propose that such highly dynamic, task-dependent and distributed relationships between cortical activity and EMGs should be taken into consideration for future brain-machine interfaces that generate EMG-like signals. PMID:25210153

Longitudinal 2-point dixon muscle magnetic resonance imaging in becker muscular dystrophy.

PubMed

Bonati, Ulrike; Schmid, Maurice; Hafner, Patricia; Haas, Tanja; Bieri, Oliver; Gloor, Monika; Fischmann, Arne; Fischer, Dirk

2015-06-01

Quantitative MRI techniques detect disease progression in myopathies more sensitively than muscle function measures or conventional MRI. To date, only conventional MRI data using visual rating scales are available for measurement of disease progression in Becker muscular dystrophy (BMD). In 3 patients with BMD (mean age 36.8 years), the mean fat fraction (MFF) of the thigh muscles was assessed by MRI at baseline and at 1-year follow-up using a 2-point Dixon approach (2PD). The motor function measurement scale (MFM) was used for clinical assessment. The mean MFF of all muscles at baseline was 61.6% (SD 7.6). It increased by 3.7% to 65.3% (SD 4.7) at follow-up. The severity of muscle involvement varied between various muscle groups. As in other myopathies, 2PD can quantify fatty muscle degeneration in BMD and can detect disease progression in a small sample size and at relatively short imaging intervals. © 2015 Wiley Periodicals, Inc.

Conflict-Triggered Top-Down Control: Default Mode, Last Resort, or No Such Thing?

ERIC Educational Resources Information Center

Bugg, Julie M.

2014-01-01

The conflict monitoring account posits that globally high levels of conflict trigger engagement of top-down control; however, recent findings point to the mercurial nature of top-down control in high conflict contexts. The current study examined the potential moderating effect of associative learning on conflict-triggered top-down control…

Novel Applications of Ultrasound Technology to Visualize and Characterize Myofascial Trigger Points and Surrounding Soft Tissue

PubMed Central

Sikdar, Siddhartha; Shah, Jay P.; Gebreab, Tadesse; Yen, Ru-Huey; Gilliams, Elizabeth; Danoff, Jerome; Gerber, Lynn H.

2009-01-01

Objective Apply ultrasound (US) imaging techniques to better describe the characteristics of myofascial trigger points (MTrPs) and the immediately adjacent soft tissue. Design Descriptive (exploratory) study. Setting Biomedical research center. Participants 9 subjects meeting Travell and Simons’s criteria for MTrPs in a taut band in the upper trapezius. Interventions (None) Main Outcome Measures MTrPs were evaluated by 1) physical examination, 2) pressure algometry, and 3) three types of ultrasound imaging including grayscale (2D US), vibration sonoelastography (VSE), and Doppler. Methods Four sites in each patient were labeled based on physical examination as either active MTrP (spontaneously-painful, A-MTrP), latent MTrP (non-painful, L-MTrP), or normal myofascial tissue. US examination was performed on each subject by a team blinded to the physical findings. A 12-5 MHz US transducer was used. VSE was performed by color Doppler variance imaging while simultaneously inducing vibrations (~92Hz) with a handheld massage vibrator. Each site was assigned a tissue imaging score (TIS) as follows: 0 = uniform echogenicity and stiffness; 1 = focal hypoechoic region with stiff nodule; 2 = multiple hypoechoic regions with stiff nodules. Blood flow in the neighborhood of MTrPs was assessed using Doppler imaging. Each site was assigned a blood flow waveform score (BFS) as follows: 0 = normal arterial flow in muscle; 1 = elevated diastolic flow; 2 = high-resistance flow waveform with retrograde diastolic flow. Results MTrPs appeared as focal, hypoechoic regions on 2D US, indicating local changes in tissue echogenicity, and as focal regions of reduced vibration amplitude on VSE, indicating a localized stiff nodule. MTrPs were elliptical in shape, with a size of 0.16 ± 0.11 cm2. There were no significant differences in size between A-MTrPs and L-MTrPs. Sites containing MTrPs were more likely to have higher TIS compared to normal myofascial tissue (p<0.002). Small arteries (or enlarged arterioles) near A-MTrPs showed retrograde flow in diastole indicating a highly resistive vascular bed. A-MTrP sites were more likely to have higher BFS compared to L-MTrPs (p<0.021). Conclusions Preliminary findings show that, under the conditions of this investigation, US imaging techniques can be used to distinguish myofascial tissue containing MTrPs from normal myofascial tissue (lacking trigger points). Ultrasound enables visualization and some characterization of MTrPs and adjacent soft tissue. PMID:19887205

Protein disulfide isomerase-mediated apoptosis and proliferation of vascular smooth muscle cells induced by mechanical stress and advanced glycosylation end products result in diabetic mouse vein graft atherosclerosis.

PubMed

Ping, Suning; Liu, Shuying; Zhou, Yuhuan; Li, Ziqing; Li, Yuhuang; Liu, Kefeng; Bardeesi, Adham Sa; Wang, Linli; Chen, Jingbo; Deng, Lie; Wang, Jingjing; Wang, Hong; Chen, Dadi; Zhang, Zhengyu; Sheng, Puyi; Li, Chaohong

2017-05-25

Protein disulfide isomerase (PDI) involves cell survival and death. Whether PDI mediates mechanical stretch stress (SS) and/or advanced glycosylation end products (AGEs) -triggered simultaneous increases in proliferation and apoptosis of vascular smooth muscle cells (VSMCs) is unknown. Here, we hypothesized that different expression levels of PDI trigger completely opposite cell fates among the different VSMC subtypes. Mouse veins were grafted into carotid arteries of non-diabetic and diabetic mice for 8 weeks; the grafted veins underwent simultaneous increases in proliferation and apoptosis, which triggered vein graft arterializations in non-diabetic or atherosclerosis in diabetic mice. A higher rate of proliferation and apoptosis was seen in the diabetic group. SS and/or AGEs stimulated the quiescent cultured VSMCs, resulting in simultaneous increases in proliferation and apoptosis; they could induce increased PDI activation and expression. Both in vivo and in vitro, the proliferating VSMCs indicated weak co-expression of PDI and SM-α-actin while apoptotic or dead cells showed strong co-expression of both. Either SS or AGEs rapidly upregulated the expression of PDI, NOX1 and ROS, and their combination had synergistic effects. Inhibiting PDI simultaneously suppressed the proliferation and apoptosis of VSMCs, while inhibition of SM-α-actin with cytochalasin D led to increased apoptosis and cleaved caspases-3 but had no effect on proliferation. In conclusion, different expression levels of PDI in VSMCs induced by SS and/or AGEs triggered a simultaneous increase in proliferation and apoptosis, accelerated vein graft arterializations or atherosclerosis, leading us to propose PDI as a novel target for the treatment of vascular remodeling and diseases.

Protein disulfide isomerase-mediated apoptosis and proliferation of vascular smooth muscle cells induced by mechanical stress and advanced glycosylation end products result in diabetic mouse vein graft atherosclerosis

PubMed Central

Ping, Suning; Liu, Shuying; Zhou, Yuhuan; Li, Ziqing; Li, Yuhuang; Liu, Kefeng; Bardeesi, Adham SA; Wang, Linli; Chen, Jingbo; Deng, Lie; Wang, Jingjing; Wang, Hong; Chen, Dadi; Zhang, Zhengyu; Sheng, Puyi; Li, Chaohong

2017-01-01

Protein disulfide isomerase (PDI) involves cell survival and death. Whether PDI mediates mechanical stretch stress (SS) and/or advanced glycosylation end products (AGEs) -triggered simultaneous increases in proliferation and apoptosis of vascular smooth muscle cells (VSMCs) is unknown. Here, we hypothesized that different expression levels of PDI trigger completely opposite cell fates among the different VSMC subtypes. Mouse veins were grafted into carotid arteries of non-diabetic and diabetic mice for 8 weeks; the grafted veins underwent simultaneous increases in proliferation and apoptosis, which triggered vein graft arterializations in non-diabetic or atherosclerosis in diabetic mice. A higher rate of proliferation and apoptosis was seen in the diabetic group. SS and/or AGEs stimulated the quiescent cultured VSMCs, resulting in simultaneous increases in proliferation and apoptosis; they could induce increased PDI activation and expression. Both in vivo and in vitro, the proliferating VSMCs indicated weak co-expression of PDI and SM-α-actin while apoptotic or dead cells showed strong co-expression of both. Either SS or AGEs rapidly upregulated the expression of PDI, NOX1 and ROS, and their combination had synergistic effects. Inhibiting PDI simultaneously suppressed the proliferation and apoptosis of VSMCs, while inhibition of SM-α-actin with cytochalasin D led to increased apoptosis and cleaved caspases-3 but had no effect on proliferation. In conclusion, different expression levels of PDI in VSMCs induced by SS and/or AGEs triggered a simultaneous increase in proliferation and apoptosis, accelerated vein graft arterializations or atherosclerosis, leading us to propose PDI as a novel target for the treatment of vascular remodeling and diseases. PMID:28542133

Changes in oxygen consumption of human muscle and tendon following repeat muscle contractions.

PubMed

Kubo, Keitaro; Ikebukuro, Toshihiro; Tsunoda, Naoya; Kanehisa, Hiroaki

2008-11-01

The purpose of this study was to investigate changes in the oxygen consumption (VO(2)) of muscle and tendon following repeat muscle contractions. During endurance tests (50 repetitions at 70% of the maximum voluntary contraction with 5-s contractions and 5-s rest) and the recovery period (0-10 min), we measured the blood volume and oxygen saturation (StO(2)) of the medial gastrocnemius muscle and Achilles tendon using near infrared spectroscopy and red laser light. Nine male subjects performed the endurance tests three times on separate days (tests-1, 2, and 3). Before and after (test-1: immediately after, test-2: at the 5-min recovery point, test-3: at the 10-min recovery point) the endurance tests, the rate of StO(2) during 8-min period of arterial occlusion was measured to estimate the VO(2) of muscle and tendon. In test-3, after the end of exercise, the THb and StO(2) of the Achilles tendon increased gradually, and these values were higher than the pre-exercise levels until the end of the recovery period. The VO(2) of tendon as well as muscle increased significantly after the repeat muscle contractions. Furthermore, the VO(2) of tendon returned to the pre-exercise level at the 10-min point of recovery, although that of muscle was significantly higher compared to the pre-exercise level until the end of the recovery period. These results indicate that the difference between oxygen supply and consumption within tendon was greater after compared to before exercise.

Retrosternal abscess after trigger point injections in a pregnant woman: a case report.

PubMed

Usman, Faisal; Bajwa, Abubakr; Shujaat, Adil; Cury, James

2011-08-23

Although retrosternal abscess is a well known complication of sternotomy and intravenous drug abuse, to date it has not been described as a consequence of trigger point injections. There are reported cases of serious complications as a result of this procedure including epidural abscess, necrotizing fasciitis, osteomyelitis and gas gangrene. A 37-year-old African-American woman, who was 20 weeks pregnant, presented to our emergency room with complaints of progressively worsening chest pain and shortness of breath over the course of the last two months. She was undergoing trigger point injections at multiple different sites including the sternoclavicular joint for chest pain and dystonia. Two years previously she had developed a left-sided pneumothorax as a result of this procedure, requiring chest tube placement and subsequent pleurodesis. Her vital signs in our emergency room were normal except for resting tachycardia, with a pulse of 100 beats per minute. A physical examination revealed swelling and tenderness of the sternal notch with tenderness to palpation over the left sternoclavicular joint. Laboratory data was significant for a white blood count of 13.3 × 109/L with 82% granulocytes. A chest radiograph revealed left basilar scarring with blunting of the left costophrenic angle. A computed tomography angiogram showed a 4.7 cm abscess in the retrosternal region behind the manubrium with associated sclerosis and cortical irregularity of the manubrium and left clavicle. Trigger point injection is generally considered very safe. However, there are reported cases of serious complications as a result of this procedure. A computed tomography scan of the chest should strongly be considered in the evaluation of chest pain and shortness of breath of unclear etiology in patients with even a remote history of trigger point injections.

Extracorporeal shock wave therapy of gastroc-soleus trigger points in patients with plantar fasciitis: A randomized, placebo-controlled trial.

PubMed

Moghtaderi, Alireza; Khosrawi, Saeid; Dehghan, Farnaz

2014-01-01

Plantar fasciitis is the most common cause of heel pain. Extracorporeal shock wave therapy (ESWT) is an alternative treatment for refractory cases of plantar fasciitis. Studies also demonstrated that ESWT may be an appropriate treatment for myofascial trigger points. This study was designed to evaluate its effectiveness by comparing the ESWT of Gastrocnemius/Soleus (gastroc-soleus) trigger points and heel region with the ESWT of the heel region alone. The study was carried out among 40 patients with a clinical diagnosis of plantar fasciitis, divided randomly to case (n = 20) and control (n = 20) groups. The case group received ESWT for the heel region and for the gastroc-soleus trigger points. The control group received ESWT just for the heel region. The protocol was the same in both groups and they were treated for three sessions every week. The pain score (100 mm visual analog score [VAS]) and the modified Roles and Maudsley score was evaluated before the first session and eight weeks after the last session. Eight weeks after the last session, although the mean VAS had decreased significantly in both groups, this decrement was more significant in the case group. (P = 0.04). According to the modified Roles and Maudsley score, there was a significant improvement in both the case (P < 0.001) and control (P = 0.01) groups, eight weeks after treatment, but there were significantly better results in the case group. The combination of ESWT for both plantar fasciitis and gastroc-soleus trigger points in treating patients with plantar fasciitis is more effective than utilizing it solely for plantar fasciitis.

cAMP levels in fast- and slow-twitch skeletal muscle after an acute bout of aerobic exercise

NASA Technical Reports Server (NTRS)

Sheldon, A.; Booth, F. W.; Kirby, C. R.

1993-01-01

The present study examined whether exercise duration was associated with elevated and/or sustained elevations of postexercise adenosine 3',5'-cyclic monophosphate (cAMP) by measuring cAMP levels in skeletal muscle for up to 4 h after acute exercise bouts of durations that are known to either produce (60 min) or not produce (10 min) mitochondrial proliferation after chronic training. Treadmill-acclimatized, but untrained, rats were run at 22 m/min for 0 (control), 10, or 60 min and were killed at various postexercise (0, 0.5, 1, 2, and 4 h) time points. Fast-twitch white and red (quadriceps) and slow-twitch (soleus) muscles were quickly excised, frozen in liquid nitrogen, and assayed for cAMP with a commercial kit. Unexpectedly, cAMP contents in all three muscles were similar to control (nonexercise) at most (21 of 30) time points after a single 10- or 60-min run. Values at 9 of 30 time points were significantly different from control (P < 0.05); i.e., 3 time points were significantly higher than control and 6 were significantly less than control. These data suggest that the cAMP concentration of untrained skeletal muscle after a single bout of endurance-type exercise is not, by itself, associated with exercise duration.

Voltage clamp methods for the study of membrane currents and SR Ca2+ release in adult skeletal muscle fibres

PubMed Central

Hernández-Ochoa, Erick O.; Schneider, Martin F.

2012-01-01

Skeletal muscle excitation-contraction (E-C)1 coupling is a process composed of multiple sequential stages, by which an action potential triggers sarcoplasmic reticulum (SR)2 Ca2+ release and subsequent contractile activation. The various steps in the E-C coupling process in skeletal muscle can be studied using different techniques. The simultaneous recordings of sarcolemmal electrical signals and the accompanying elevation in myoplasmic Ca2+, due to depolarization-initiated SR Ca2+ release in skeletal muscle fibres, have been useful to obtain a better understanding of muscle function. In studying the origin and mechanism of voltage dependency of E-C coupling a variety of different techniques have been used to control the voltage in adult skeletal fibres. Pioneering work in muscles isolated from amphibians or crustaceans used microelectrodes or ‘high resistance gap’ techniques to manipulate the voltage in the muscle fibres. The development of the patch clamp technique and its variant, the whole-cell clamp configuration that facilitates the manipulation of the intracellular environment, allowed the use of the voltage clamp techniques in different cell types, including skeletal muscle fibres. The aim of this article is to present an historical perspective of the voltage clamp methods used to study skeletal muscle E-C coupling as well as to describe the current status of using the whole-cell patch clamp technique in studies in which the electrical and Ca2+ signalling properties of mouse skeletal muscle membranes are being investigated. PMID:22306655

Mesoangioblasts from facioscapulohumeral muscular dystrophy display in vivo a variable myogenic ability predictable by their in vitro behavior.

PubMed

Morosetti, Roberta; Gidaro, Teresa; Broccolini, Aldobrando; Gliubizzi, Carla; Sancricca, Cristina; Tonali, Pietro Attilio; Ricci, Enzo; Mirabella, Massimiliano

2011-01-01

Facioscapulohumeral muscular dystrophy (FSHD) is the third most frequent inherited myopathy. We previously demonstrated that mesoangioblasts can be efficiently isolated from FSHD muscles, although their differentiation ability into skeletal muscle was variably impaired. This correlates with overall disease severity and degree of histopathologic abnormalities, since mesoangioblasts from morphologically normal muscles did not show any myogenic differentiation block. The aim of our present study was to verify whether mesoangioblasts from differentially affected FSHD muscles reproduce in vivo the same differentiation ability shown in vitro by studying their capability to form new muscle fibers during muscle regeneration of experimentally damaged muscles. We show that a diverse ability of FSHD mesoangioblasts to engraft and differentiate into skeletal muscle of SCID mice is strictly related to the characteristics of the muscle of origin, closely replicating in vivo what was previously observed in vitro. Moreover, we demonstrate that mesoangioblasts obtained from severely affected muscles scarcely integrate into muscle fibers, remaining mainly localized in the connective tissue. This suggests a defective migration in response to chemoattractants released by damaged fibers, as indicated by cell migration assays in response to HMGB1 and very low levels of RAGE expression, along with a decreased ability to fuse or to appropriately trigger the myogenic program. Our study indicates that FSHD mesoangioblasts from unaffected muscles can be used as selective treatment to halt muscle degeneration in severely affected muscles, and suggests that pharmacological and molecular interventions aimed to ameliorate homing and engraftment of transplanted autologous mesoangioblasts may open the way to cell therapy for FSHD patients, without requiring immunosuppression or genetic correction in vitro.

Role of mast cells in bronchial contraction in nonallergic obstructive lung pathology.

PubMed

Kuzubova, Nataliya A; Lebedeva, Elena S; Titova, Olga N; Fedin, Anatoliy N; Dvorakovskaya, Ivetta V

2017-01-01

The role of mast cells in contractile bronchial smooth muscle activity has been evaluated in a model of chronic obstructive pulmonary disease induced in rats that were intermittently exposed to nitrogen dioxide (NO 2 ) for 60 days. Starting from the 31st day, one group of rats inhaled sodium cromoglycate before exposure to NO 2 to stabilize mast cell membranes. The second group (control) was not treated. Isometric smooth muscle contraction was analysed in isolated bronchial samples in response to nerve and smooth muscle stimulation. Histological analysis revealed large numbers of mast cells in lung tissue of COPD model rats. The inhibition of mast cell degranulation by sodium cromoglycate prevented the development of nerve-stimulated bronchial smooth muscle hyperactivity in COPD model rats. Histamine or adenosine-induced hyperactivity on nerve stimulation was also inhibited by sodium cromoglycate in bronchial smooth muscle in both control and COPD model rats. This suggests that the mechanism of contractile activity enhancement of bronchial wall smooth muscle cells may be mediated through the activation of resident mast cells transmembrane adenosine receptors resulting in their partial degranulation, with the released histamine acting upon histamine H1-receptors which trigger reflex pathways via intramural ganglion neurons.

Pigment epithelium-derived factor stimulates skeletal muscle glycolytic activity through NADPH oxidase-dependent reactive oxygen species production.

PubMed

Carnagarin, Revathy; Carlessi, Rodrigo; Newsholme, Philip; Dharmarajan, Arun M; Dass, Crispin R

2016-09-01

Pigment epithelium-derived factor is a multifunctional serpin implicated in insulin resistance in metabolic disorders. Recent evidence suggests that exposure of peripheral tissues such as skeletal muscle to PEDF has profound metabolic consequences with predisposition towards chronic conditions such as obesity, type 2 diabetes, metabolic syndrome and polycystic ovarian syndrome. Chronic inflammation shifts muscle metabolism towards increased glycolysis and decreased oxidative metabolism. In the present study, we demonstrate a novel effect of PEDF on cellular metabolism in mouse cell line (C2C12) and human primary skeletal muscle cells. PEDF addition to skeletal muscle cells induced enhanced phospholipase A2 activity. This was accompanied with increased production of reactive oxygen species in a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-dependent manner that triggered a shift towards a more glycolytic phenotype. Extracellular flux analysis and glucose consumption assays demonstrated that PEDF treatment resulted in enhanced glycolysis but did not change mitochondrial respiration. Our results demonstrate that skeletal muscle cells express a PEDF-inducible oxidant generating system that enhances glycolysis but is sensitive to antioxidants and NADPH oxidase inhibition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Role of mast cells in bronchial contraction in nonallergic obstructive lung pathology

PubMed Central

Kuzubova, Nataliya A.; Lebedeva, Elena S.; Titova, Olga N.; Fedin, Anatoliy N.; Dvorakovskaya, Ivetta V.

2017-01-01

Abstract The role of mast cells in contractile bronchial smooth muscle activity has been evaluated in a model of chronic obstructive pulmonary disease induced in rats that were intermittently exposed to nitrogen dioxide (NO2) for 60 days. Starting from the 31st day, one group of rats inhaled sodium cromoglycate before exposure to NO2 to stabilize mast cell membranes. The second group (control) was not treated. Isometric smooth muscle contraction was analysed in isolated bronchial samples in response to nerve and smooth muscle stimulation. Histological analysis revealed large numbers of mast cells in lung tissue of COPD model rats. The inhibition of mast cell degranulation by sodium cromoglycate prevented the development of nerve-stimulated bronchial smooth muscle hyperactivity in COPD model rats. Histamine or adenosine-induced hyperactivity on nerve stimulation was also inhibited by sodium cromoglycate in bronchial smooth muscle in both control and COPD model rats. This suggests that the mechanism of contractile activity enhancement of bronchial wall smooth muscle cells may be mediated through the activation of resident mast cells transmembrane adenosine receptors resulting in their partial degranulation, with the released histamine acting upon histamine H1-receptors which trigger reflex pathways via intramural ganglion neurons. PMID:28867718

Localized intracellular calcium signaling in muscle: calcium sparks and calcium quarks.

PubMed

Niggli, E

1999-01-01

Subcellularly localized Ca2+ signals in cardiac and skeletal muscle have recently been identified as elementary Ca2+ signaling events. The signals, termed Ca2+ sparks and Ca2+ quarks, represent openings of Ca2+ release channels located in the membrane of the sarcoplasmic reticulum (SR). In cardiac muscle, the revolutionary discovery of Ca2+ sparks has allowed the development of a fundamentally different concept for the amplification of Ca2+ signals by Ca(2+)-induced Ca2+ release. In such a system, a graded amplification of the triggering Ca2+ signal entering the myocyte via L-type Ca2+ channels is accomplished by a recruitment process whereby individual SR Ca2+ release units are locally controlled by L-type Ca2+ channels. In skeletal muscle, the initial SR Ca2+ release is governed by voltage-sensors but subsequently activates additional Ca2+ sparks by Ca(2+)-induced Ca2+ release from the SR. Results from studies on elementary Ca2+ release events will improve our knowledge of muscle Ca2+ signaling at all levels of complexity, from the molecule to normal cellular function, and from the regulation of cardiac and skeletal muscle force to the pathophysiology of excitation-contraction coupling.

A new Caenorhabditis elegans model of human huntingtin 513 aggregation and toxicity in body wall muscles.

PubMed

Lee, Amy L; Ung, Hailey M; Sands, L Paul; Kikis, Elise A

2017-01-01

Expanded polyglutamine repeats in different proteins are the known determinants of at least nine progressive neurodegenerative disorders whose symptoms include cognitive and motor impairment that worsen as patients age. One such disorder is Huntington's Disease (HD) that is caused by a polyglutamine expansion in the human huntingtin protein (htt). The polyglutamine expansion destabilizes htt leading to protein misfolding, which in turn triggers neurodegeneration and the disruption of energy metabolism in muscle cells. However, the molecular mechanisms that underlie htt proteotoxicity have been somewhat elusive, and the muscle phenotypes have not been well studied. To generate tools to elucidate the basis for muscle dysfunction, we engineered Caenorhabditis elegans to express a disease-associated 513 amino acid fragment of human htt in body wall muscle cells. We show that this htt fragment aggregates in C. elegans in a polyglutamine length-dependent manner and is toxic. Toxicity manifests as motor impairment and a shortened lifespan. Compared to previous models, the data suggest that the protein context in which a polyglutamine tract is embedded alters aggregation propensity and toxicity, likely by affecting interactions with the muscle cell environment.

Kinematics, muscular activity and propulsion in gopher snakes

PubMed

Moon; Gans

1998-10-01

Previous studies have addressed the physical principles and muscular activity patterns underlying terrestrial lateral undulation in snakes, but not the mechanism by which muscular activity produces curvature and propulsion. In this study, we used synchronized electromyography and videography to examine the muscular basis and propulsive mechanism of terrestrial lateral undulation in gopher snakes Pituophis melanoleucus affinis. Specifically, we used patch electrodes to record from the semispinalis, longissimus dorsi and iliocostalis muscles in snakes pushing against one or more pegs. Axial bends propagate posteriorly along the body and contact the pegs at or immediately posterior to an inflection of curvature, which then reverses anterior to the peg. The vertebral column bends broadly around a peg, whereas the body wall bends sharply and asymmetrically around the anterior surface of the peg. The epaxial muscles are always active contralateral to the point of contact with a peg; they are activated slightly before or at the point of maximal convexity and deactivated variably between the inflection point and the point of maximal concavity. This pattern is consistent with muscular shortening and the production of axial bends, although variability in the pattern indicates that other muscles may affect the mechanics of the epaxial muscles. The kinematic and motor patterns in snakes crawling against experimentally increased drag indicated that forces are produced largely by muscles that are active in the axial bend around each peg, rather than by distant muscles from which the forces might be transmitted by connective tissues. At each point of force exertion, the propulsive mechanism of terrestrial lateral undulation may be modeled as a type of cam-follower, in which continuous bending of the trunk around the peg produces translation of the snake.

The acute benefits and risks of passive stretching to the point of pain.

PubMed

Muanjai, Pornpimol; Jones, David A; Mickevicius, Mantas; Satkunskiene, Danguole; Snieckus, Audrius; Skurvydas, Albertas; Kamandulis, Sigitas

2017-06-01

This study evaluated the acute effects of two different stretch intensities on muscle damage and extensibility. Twenty-two physically active women (age 20 ± 1.0 years) were divided into two matched groups and undertook eight sets of 30-s passive hamstring stretching. One group stretched to the point of discomfort (POD) and the other to the point of pain (POP). Hamstring passive torque, sit and reach (S&R), straight leg raise (SLR), and markers of muscle damage were measured before, immediately after stretching and 24 h later. S&R acutely increased and was still increased at 24 h with median (interquartile range) of 2.0 cm (0.5-3.75 cm) and 2.0 cm (0.25-3.0 cm) for POP and POD (p < 0.05), respectively, with no difference between groups; similar changes were seen with SLR. Passive stiffness fully recovered by 24 h and there was no torque deficit. A small, but significant increase in muscle tenderness occurred at 24 h in both groups and there was a very small increase in thigh circumference in both groups which persisted at 24 h in POP. Plasma CK activity was not raised at 24 h. Stretching to the point of pain had no acute advantages over stretching to the discomfort point. Both forms of stretching resulted in very mild muscle tenderness but with no evidence of muscle damage. The increased ROM was not associated with changes in passive stiffness of the muscle but most likely resulted from increased tolerance of the discomfort.

Chronic pain in a patient with Ehlers-Danlos syndrome (hypermobility type): The role of myofascial trigger point injections.

PubMed

Tewari, Saipriya; Madabushi, Rajashree; Agarwal, Anil; Gautam, Sujeet K; Khuba, Sandeep

2017-01-01

Chronic widespread musculoskeletal pain is a cardinal symptom in hypermobility type of Ehler Danlos Syndrome (EDS type III). The management of pain in EDS, however, has not been studied in depth. A 30 year old female, known case of EDS, presented to the pain clinic with complaints of severe upper back pain for 6 months. Physical examination of the back revealed two myofascial trigger points over the left rhomboids and the left erector spinae. Local anaesthetic trigger point injections were given at these points, followed by stretching exercises under analgesic cover for the first week. After 1 week the patient reported 60-80% pain relief. This case highlights that we must keep a high index of suspicion for the more treatable causes of pain like myofascial pain syndrome in patients suffering from EDS, and should address it promptly and appropriately in order to maximise patient comfort. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fish skeletal muscle tissue is an important focus of immune reactions during pathogen infection.

PubMed

Valenzuela, Cristián A; Zuloaga, Rodrigo; Poblete-Morales, Matías; Vera-Tobar, Tamara; Mercado, Luis; Avendaño-Herrera, Ruben; Valdés, Juan Antonio; Molina, Alfredo

2017-08-01

Skeletal muscle in mammals can express and secrete immune-related molecules during pathogen infection. Despite in fish is known that classical immune tissues participate in innate immunity, the role of skeletal muscle in this function is poorly understood. To determine the immunocompetence of fish skeletal muscle, juvenile fine flounder (Paralichthys adpersus) were challenged with Vibrio ordalii. Different Toll-like receptors, pro-inflammatory cytokines (TNFα, Il-1β, and IL-8), and immune-effector molecules (NKEF and the antimicrobial peptides hepcidin and LEAP-2) were analyzed. Infection initially triggered IL-1β upregulation and P38-MAPK/AP-1 pathway activation. Next, the NFĸB pathway was activated, together with an upregulation of intracellular Toll-like receptor expressions (tlr3, tlr8a tlr9, and tlr21), TNFα production, and leap-2 expression. Finally, transcriptions of il-1β, il-8, tnfα, nkef-a, and hepcidin were also upregulated. These results suggest that fish skeletal muscle is an immunologically active organ that could play an important role against pathogens. Copyright © 2017 Elsevier Ltd. All rights reserved.

Activity Dependent Signal Transduction in Skeletal Muscle

NASA Technical Reports Server (NTRS)

Hamilton, Susan L.

1999-01-01

The overall goals of this project are: 1) to define the initial signal transduction events whereby the removal of gravitational load from antigravity muscles, such as the soleus, triggers muscle atrophy, and 2) to develop countermeasures to prevent this from happening. Our rationale for this approach is that, if countermeasures can be developed to regulate these early events, we could avoid having to deal with the multiple cascades of events that occur downstream from the initial event. One of our major findings is that hind limb suspension causes an early and sustained increase in intracellular Ca(2+) concentration ([Ca (2+)](sub i)). In most cells the consequences of changes in ([Ca (2+)](sub i))depend on the amplitude, frequency and duration of the Ca(2+) signal and on other factors in the intracellular environment. We propose that muscle remodeling in microgravity represents a change in the balance among several CA(2+) regulated signal transduction pathways, in particular those involving the transcription factors NFAT and NFkB and the pro-apoptotic protein BAD. Other Ca(2+) sensitive pathways involving PKC, ras, rac, and CaM kinase II may also contribute to muscle remodeling.

[New insights of myositis-specific and -associated autoantibodies in juvenile and adult type myositis].

PubMed

Váncsa, Andrea; Dankó, Katalin

2016-07-01

Myositis, which means inflammation of the muscles, is a general term used for inflammatory myopathies. Myositis is a rare idiopathic autoimmune disease. It is believed that environmental factors such as virus, bacteria, parasites, direct injuries, drugs side effect can trigger the immune system of genetically susceptible individuals to act against muscle tissues. There are several types of myositis with the same systemic symptoms such as muscle weakness, fatigue, muscle pain and inflammation. These include dermatomyositis, juvenile dermatomyositis, inclusion-body myositis, polymyositis, orbital myositis and myositis ossificans. Juvenile and adult dermatomyositis are chronic, immune-mediated inflammatory myopathies characterized by progressive proximal muscle weakness and typical skin symptoms. The aim of the authors was to compare the symptoms, laboratory and serological findings and disease course in children and adult patients with idiopathic inflammatory myopathy. Early diagnosis and aggressive immunosuppressive treatment improve the mortality of these patients. Myositis-specific autoantibodies have predictive and prognostic values regarding the associated overlap disease, response to treatment and disease course. The authors intend to lighten the clinical and pathogenetic significance of the new target autoantigens. Orv. Hetil., 2016, 157(29), 1179-1184.

[Malignant hyperthermia in a black child. A case report].

PubMed

Hugo, J M; Ungerer, M J; Erasmus, F R; du Toit, P W; Muller, F O; van Velden, D J

1978-05-20

A case of malignant hyperthermia in a Black boy is presented. He developed this condition during repair of a cleft palate, with halothane as the triggering agent. The importance of the high incidence of malignant hyperthermia in patients with certain musculoskeletal abnormalities is stressed. Despite a cool and well air-conditioned theatre, the patient's temperature was 41 degree C when the condition was suspected. At that stage general muscle rigidity was present. The patient was successfully treated with procainamide, sodium bicarbonate and hydrocortisone; surface cooling (with ice packs) was instituted and the stomach was washed out with ice-cold Ringer's solution. Over a period of 14 days serum creatine phosphokinase values decreased from 630 IU (on the day of the incident) to 12 IU. A muscle biopsy showed variation in muscle fibre size. Electron microscopical studies showed myofibrillar disruption and folding of the basement membrane. A modified version of Denborough's technique was used for the in vitro exposure of muscle strips to halothane and suxamethonium. Isometric contraction was measured and recorded. A severe contraction followed the exposure of muscle strips to halothane, which confirmed the diagnosis.

Relationships between motor unit size and recruitment threshold in older adults: implications for size principle.

PubMed

Fling, Brett W; Knight, Christopher A; Kamen, Gary

2009-08-01

As a part of the aging process, motor unit reorganization occurs in which small motoneurons reinnervate predominantly fast-twitch muscle fibers that have lost their innervation. We examined the relationship between motor unit size and the threshold force for recruitment in two muscles to determine whether older individuals might develop an alternative pattern of motor unit activation. Young and older adults performed isometric contractions ranging from 0 to 50% of maximal voluntary contraction in both the first dorsal interosseous (FDI) and tibialis anterior (TA) muscles. Muscle fiber action potentials were recorded with an intramuscular needle electrode and motor unit size was computed using spike-triggered averaging of the global EMG signal (macro EMG), which was also obtained from the intramuscular needle electrode. As expected, older individuals exhibited larger motor units than young subjects in both the FDI and the TA. However, moderately strong correlations were obtained for the macro EMG amplitude versus recruitment threshold relationship in both the young and older adults within both muscles, suggesting that the size principle of motor unit recruitment seems to be preserved in older adults.

The flexibility of two tropomyosin mutants, D175N and E180G, that cause hypertrophic cardiomyopathy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xiaochuan; Suphamungmee, Worawit; Janco, Miro

2012-08-03

Highlights: Black-Right-Pointing-Pointer Well-known tropomyosin mutants, D175N and E180G are linked to cardiomyopathies. Black-Right-Pointing-Pointer The structural mechanics of D175N and E180G tropomyosins have been investigated. Black-Right-Pointing-Pointer D175N and E180G mutations increase both local and global tropomyosin flexibility. Black-Right-Pointing-Pointer In muscle, this increased flexibility will enhance myosin interactions on actin. Black-Right-Pointing-Pointer Extra myosin interaction can alter cardiac Ca{sup 2+}-switching, leading to dysfunction. -- Abstract: Point mutations targeting muscle thin filament proteins are the cause of a number of cardiomyopathies. In many cases, biological effects of the mutations are well-documented, whereas their structural and mechanical impact on filament assembly and regulatory function ismore » lacking. In order to elucidate molecular defects leading to cardiac dysfunction, we have examined the structural mechanics of two tropomyosin mutants, E180G and D175N, which are associated with hypertrophic cardiomyopathy (HCM). Tropomyosin is an {alpha}-helical coiled-coil dimer which polymerizes end-to-end to create an elongated superhelix that wraps around F-actin filaments of muscle and non-muscle cells, thus modulating the binding of other actin-binding proteins. Here, we study how flexibility changes in the E180G and D175N mutants might affect tropomyosin binding and regulatory motion on F-actin. Electron microscopy and Molecular Dynamics simulations show that E180G and D175N mutations cause an increase in bending flexibility of tropomyosin both locally and globally. This excess flexibility is likely to increase accessibility of the myosin-binding sites on F-actin, thus destabilizing the low-Ca{sup 2+} relaxed-state of cardiac muscle. The resulting imbalance in the on-off switching mechanism of the mutants will shift the regulatory equilibrium towards Ca{sup 2+}-activation of cardiac muscle, as is observed in affected muscle, accompanied by enhanced systolic activity, diastolic dysfunction, and cardiac compensations associated with HCM and heart failure.« less

Altered Skeletal Muscle Mitochondrial Proteome As the Basis of Disruption of Mitochondrial Function in Diabetic Mice

PubMed Central

Zabielski, Piotr; Lanza, Ian R.; Gopala, Srinivas; Holtz Heppelmann, Carrie J.; Bergen, H. Robert; Dasari, Surendra

2016-01-01

Insulin plays pivotal role in cellular fuel metabolism in skeletal muscle. Despite being the primary site of energy metabolism, the underlying mechanism on how insulin deficiency deranges skeletal muscle mitochondrial physiology remains to be fully understood. Here we report an important link between altered skeletal muscle proteome homeostasis and mitochondrial physiology during insulin deficiency. Deprivation of insulin in streptozotocin-induced diabetic mice decreased mitochondrial ATP production, reduced coupling and phosphorylation efficiency, and increased oxidant emission in skeletal muscle. Proteomic survey revealed that the mitochondrial derangements during insulin deficiency were related to increased mitochondrial protein degradation and decreased protein synthesis, resulting in reduced abundance of proteins involved in mitochondrial respiration and β-oxidation. However, a paradoxical upregulation of proteins involved in cellular uptake of fatty acids triggered an accumulation of incomplete fatty acid oxidation products in skeletal muscle. These data implicate a mismatch of β-oxidation and fatty acid uptake as a mechanism leading to increased oxidative stress in diabetes. This notion was supported by elevated oxidative stress in cultured myotubes exposed to palmitate in the presence of a β-oxidation inhibitor. Together, these results indicate that insulin deficiency alters the balance of proteins involved in fatty acid transport and oxidation in skeletal muscle, leading to impaired mitochondrial function and increased oxidative stress. PMID:26718503

Osmosensation in TRPV2 dominant negative expressing skeletal muscle fibres

PubMed Central

Zanou, Nadège; Mondin, Ludivine; Fuster, Clarisse; Seghers, François; Dufour, Inès; de Clippele, Marie; Schakman, Olivier; Tajeddine, Nicolas; Iwata, Yuko; Wakabayashi, Shigeo; Voets, Thomas; Allard, Bruno; Gailly, Philippe

2015-01-01

Abstract Increased plasma osmolarity induces intracellular water depletion and cell shrinkage followed by activation of a regulatory volume increase (RVI). In skeletal muscle, this is accompanied by transverse tubule (TT) dilatation and by a membrane depolarization responsible for a release of Ca2+ from intracellular pools. We observed that both hyperosmotic shock-induced Ca2+ transients and RVI were inhibited by Gd3+, ruthenium red and GsMTx4 toxin, three inhibitors of mechanosensitive ion channels. The response was also completely absent in muscle fibres overexpressing a non-permeant, dominant negative (DN) mutant of the transient receptor potential, V2 isoform (TRPV2) ion channel, suggesting the involvement of TRPV2 or of a TRP isoform susceptible to heterotetramerization with TRPV2. The release of Ca2+ induced by hyperosmotic shock was increased by cannabidiol, an activator of TRPV2, and decreased by tranilast, an inhibitor of TRPV2, suggesting a role for the TRPV2 channel itself. Hyperosmotic shock-induced membrane depolarization was impaired in TRPV2-DN fibres, suggesting that TRPV2 activation triggers the release of Ca2+ from the sarcoplasmic reticulum by depolarizing TTs. RVI requires the sequential activation of STE20/SPS1-related proline/alanine-rich kinase (SPAK) and NKCC1, a Na+–K+–Cl− cotransporter, allowing ion entry and driving osmotic water flow. In fibres overexpressing TRPV2-DN as well as in fibres in which Ca2+ transients were abolished by the Ca2+ chelator BAPTA, the level of P-SPAKSer373 in response to hyperosmotic shock was reduced, suggesting a modulation of SPAK phosphorylation by intracellular Ca2+. We conclude that TRPV2 is involved in osmosensation in skeletal muscle fibres, acting in concert with P-SPAK-activated NKCC1. Key points Increased plasma osmolarity induces intracellular water depletion and cell shrinkage (CS) followed by activation of a regulatory volume increase (RVI). In skeletal muscle, the hyperosmotic shock-induced CS is accompanied by a small membrane depolarization responsible for a release of Ca2+ from intracellular pools. Hyperosmotic shock also induces phosphorylation of STE20/SPS1-related proline/alanine-rich kinase (SPAK). TRPV2 dominant negative expressing fibres challenged with hyperosmotic shock present a slower membrane depolarization, a diminished Ca2+ response, a smaller RVI response, a decrease in SPAK phosphorylation and defective muscle function. We suggest that hyperosmotic shock induces TRPV2 activation, which accelerates muscle cell depolarization and allows the subsequent Ca2+ release from the sarcoplasmic reticulum, activation of the Na+–K+–Cl− cotransporter by SPAK, and the RVI response. PMID:26108786

Early Detection of Heterotopic Ossification for Effective Prevention and Treatment

DTIC Science & Technology

2014-04-01

selectively induced in rat model of myocardial infarction . Inflammation. 2001;25(5):293-300. 20. Tögel F, Isaac J, Hu Z, Weiss K, Westenfelder C. Renal SDF...the development of HO, subtle muscle injuries could trigger SDF-1 build-up locally and MSC recruitment. This project is based on a hypothesis that

Reduced surround inhibition in musicians.

PubMed

Shin, Hae-Won; Kang, Suk Y; Hallett, Mark; Sohn, Young H

2012-06-01

To investigate whether surround inhibition (SI) in the motor system is altered in professional musicians, we performed a transcranial magnetic stimulation (TMS) study in 10 professional musicians and 15 age-matched healthy non-musicians. TMS was set to be triggered by self-initiated flexion of the index finger at different intervals ranging from 3 to 1,000 ms. Average motor evoked potential (MEP) amplitudes obtained from self-triggered TMS were normalized to average MEPs of the control TMS at rest and expressed as a percentage. Normalized MEP amplitudes of the abductor digiti minimi (ADM) muscles were compared between the musicians and non-musicians with the primary analysis being the intervals between 3 and 80 ms (during the movement). A mixed-design ANOVA revealed a significant difference in normalized ADM MEPs during the index finger flexion between groups, with less SI in the musicians. This study demonstrated that the functional operation of SI is less strong in musicians than non-musicians, perhaps due to practice of movement synergies involving both muscles. Reduced SI, however, could lead susceptible musicians to be prone to develop task-specific dystonia.

Smooth muscle myosin light chain kinase efficiently phosphorylates serine 15 of cardiac myosin regulatory light chain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Josephson, Matthew P.; Sikkink, Laura A.; Penheiter, Alan R.

2011-12-16

Highlights: Black-Right-Pointing-Pointer Cardiac myosin regulatory light chain (MYL2) is phosphorylated at S15. Black-Right-Pointing-Pointer Smooth muscle myosin light chain kinase (smMLCK) is a ubiquitous kinase. Black-Right-Pointing-Pointer It is a widely believed that MYL2 is a poor substrate for smMLCK. Black-Right-Pointing-Pointer In fact, smMLCK efficiently and rapidly phosphorylates S15 in MYL2. Black-Right-Pointing-Pointer Phosphorylation kinetics measured by novel fluorescence method without radioactivity. -- Abstract: Specific phosphorylation of the human ventricular cardiac myosin regulatory light chain (MYL2) modifies the protein at S15. This modification affects MYL2 secondary structure and modulates the Ca{sup 2+} sensitivity of contraction in cardiac tissue. Smooth muscle myosin light chainmore » kinase (smMLCK) is a ubiquitous kinase prevalent in uterus and present in other contracting tissues including cardiac muscle. The recombinant 130 kDa (short) smMLCK phosphorylated S15 in MYL2 in vitro. Specific modification of S15 was verified using the direct detection of the phospho group on S15 with mass spectrometry. SmMLCK also specifically phosphorylated myosin regulatory light chain S15 in porcine ventricular myosin and chicken gizzard smooth muscle myosin (S20 in smooth muscle) but failed to phosphorylate the myosin regulatory light chain in rabbit skeletal myosin. Phosphorylation kinetics, measured using a novel fluorescence method eliminating the use of radioactive isotopes, indicates similar Michaelis-Menten V{sub max} and K{sub M} for regulatory light chain S15 phosphorylation rates in MYL2, porcine ventricular myosin, and chicken gizzard myosin. These data demonstrate that smMLCK is a specific and efficient kinase for the in vitro phosphorylation of MYL2, cardiac, and smooth muscle myosin. Whether smMLCK plays a role in cardiac muscle regulation or response to a disease causing stimulus is unclear but it should be considered a potentially significant kinase in cardiac tissue on the basis of its specificity, kinetics, and tissue expression.« less

Effects of photobiomodulation therapy and topical non-steroidal anti-inflammatory drug on skeletal muscle injury induced by contusion in rats-part 2: biochemical aspects.

PubMed

Tomazoni, Shaiane Silva; Frigo, Lúcio; Dos Reis Ferreira, Tereza Cristina; Casalechi, Heliodora Leão; Teixeira, Simone; de Almeida, Patrícia; Muscara, Marcelo Nicolas; Marcos, Rodrigo Labat; Serra, Andrey Jorge; de Carvalho, Paulo de Tarso Camillo; Leal-Junior, Ernesto Cesar Pinto

2017-11-01

Muscle injuries trigger an inflammatory process, releasing important biochemical markers for tissue regeneration. The use of non-steroidal anti-inflammatory drugs (NSAIDs) is the treatment of choice to promote pain relief due to muscle injury. NSAIDs exhibit several adverse effects and their efficacy is questionable. Photobiomodulation therapy (PBMT) has been demonstrated to effectively modulate inflammation induced from musculoskeletal disorders and may be used as an alternative to NSAIDs. Here, we assessed and compared the effects of different doses of PBMT and topical NSAIDs on biochemical parameters during an acute inflammatory process triggered by a controlled model of contusion-induced musculoskeletal injury in rats. Muscle injury was induced by trauma to the anterior tibial muscle of rats. After 1 h, rats were treated with PBMT (830 nm, continuous mode, 100 mW of power, 35.71 W/cm 2 ; 1, 3, and 9 J; 10, 30, and 90 s) or diclofenac sodium (1 g). Our results demonstrated that PBMT, 1 J (35.7 J/cm 2 ), 3 J (107.1 J/cm 2 ), and 9 J (321.4 J/cm 2 ) reduced the expression of tumor necrosis factor alpha (TNF-α) and cyclooxygenase-2 (COX-2) genes at all assessed times as compared to the injury and diclofenac groups (p < 0.05). The diclofenac group showed reduced levels of COX-2 only in relation to the injury group (p < 0.05). COX-2 protein expression remained unchanged with all therapies except with PBMT at a 3-J dose at 12 h (p < 0.05 compared to the injury group). In addition, PBMT (1, 3, and 9 J) effectively reduced levels of cytokines TNF-α, interleukin (IL)-1β, and IL-6 at all assessed times as compared to the injury and diclofenac groups (p < 0.05). Thus, PBMT at a 3-J dose was more effective than other doses of PBMT and topical NSAIDs in the modulation of the inflammatory process caused by muscle contusion injuries.

Onset of Oviposition Triggers Abrupt Reduction in Migratory Flight Behavior and Flight Muscle in the Female Beet Webworm, Loxostege sticticalis

PubMed Central

Cheng, Yunxia; Luo, Lizhi; Sappington, Thomas W.; Jiang, Xingfu; Zhang, Lei; Frolov, Andrei N.

2016-01-01

Flight and reproduction are usually considered as two life history traits that compete for resources in a migratory insect. The beet webworm, Loxostege sticticalis L., manages the costs of migratory flight and reproduction through a trade-off in timing of these two life history traits, where migratory behavior occurs during the preoviposition period. To gain insight into how migratory flight and reproduction are coordinated in the female beet webworm, we conducted experiments beginning at the end of the preoviposition period. We used flight mills to test whether flight performance and supportive flight musculature and fuel are affected by the number of eggs oviposited, or by the age of mated and unmated females after onset of oviposition by the former. The results showed that flight distance, flight velocity, flight duration, and flight muscle mass decreased abruptly at the onset of oviposition, compared to that of virgin females of the same age which did not change over the next 7 d. These results indicate that onset of oviposition triggers a decrease in flight performance and capacity in female beet webworms, as a way of actively managing reallocation of resources away from migratory flight and into egg production. In addition to the abrupt switch, there was a gradual, linear decline in flight performance, flight muscle mass, and flight fuel relative to the number of eggs oviposited. The histolysis of flight muscle and decrease of triglyceride content indicate a progressive degradation in the ability of adults to perform additional migratory flights after onset of oviposition. Although the results show that substantial, albeit reduced, long-duration flights remain possible after oviposition begins, additional long-distance migratory flights probably are not launched after the initiation of oviposition. PMID:27893835

Onset of Oviposition Triggers Abrupt Reduction in Migratory Flight Behavior and Flight Muscle in the Female Beet Webworm, Loxostege sticticalis.

PubMed

Cheng, Yunxia; Luo, Lizhi; Sappington, Thomas W; Jiang, Xingfu; Zhang, Lei; Frolov, Andrei N

2016-01-01

Flight and reproduction are usually considered as two life history traits that compete for resources in a migratory insect. The beet webworm, Loxostege sticticalis L., manages the costs of migratory flight and reproduction through a trade-off in timing of these two life history traits, where migratory behavior occurs during the preoviposition period. To gain insight into how migratory flight and reproduction are coordinated in the female beet webworm, we conducted experiments beginning at the end of the preoviposition period. We used flight mills to test whether flight performance and supportive flight musculature and fuel are affected by the number of eggs oviposited, or by the age of mated and unmated females after onset of oviposition by the former. The results showed that flight distance, flight velocity, flight duration, and flight muscle mass decreased abruptly at the onset of oviposition, compared to that of virgin females of the same age which did not change over the next 7 d. These results indicate that onset of oviposition triggers a decrease in flight performance and capacity in female beet webworms, as a way of actively managing reallocation of resources away from migratory flight and into egg production. In addition to the abrupt switch, there was a gradual, linear decline in flight performance, flight muscle mass, and flight fuel relative to the number of eggs oviposited. The histolysis of flight muscle and decrease of triglyceride content indicate a progressive degradation in the ability of adults to perform additional migratory flights after onset of oviposition. Although the results show that substantial, albeit reduced, long-duration flights remain possible after oviposition begins, additional long-distance migratory flights probably are not launched after the initiation of oviposition.

Tissue remodeling: a mating-induced differentiation program for the Drosophila oviduct.

PubMed

Kapelnikov, Anat; Rivlin, Patricia K; Hoy, Ronald R; Heifetz, Yael

2008-12-08

In both vertebrates and invertebrates, the oviduct is an epithelial tube surrounded by visceral muscles that serves as a conduit for gamete transport between the ovary and uterus. While Drosophila is a model system for tubular organ development, few studies have addressed the development of the fly's oviduct. Recent studies in Drosophila have identified mating-responsive genes and proteins whose levels in the oviduct are altered by mating. Since many of these molecules (e.g. Muscle LIM protein 84B, Coracle, Neuroglian) have known roles in the differentiation of muscle and epithelia of other organs, mating may trigger similar differentiation events in the oviduct. This led us to hypothesize that mating mediates the last stages of oviduct differentiation in which organ-specific specializations arise. Using electron- and confocal-microscopy we identified tissue-wide post-mating changes in the oviduct including differentiation of cellular junctions, remodeling of extracellular matrix, increased myofibril formation, and increased innervation. Analysis of once- and twice-mated females reveals that some mating-responsive proteins respond only to the first mating, while others respond to both matings. We uncovered ultrastructural changes in the mated oviduct that are consistent with the roles that mating-responsive proteins play in muscle and epithelial differentiation elsewhere. This suggests that mating triggers the late differentiation of the oviduct. Furthermore, we suggest that mating-responsive proteins that respond only to the first mating are involved in the final maturation of the oviduct while proteins that remain responsive to later matings are also involved in maintenance and ongoing function of the oviduct. Taken together, our results establish the oviduct as an attractive system to address mechanisms that regulate the late stages of differentiation and maintenance of a tubular organ.

Tissue remodeling: a mating-induced differentiation program for the Drosophila oviduct

PubMed Central

Kapelnikov, Anat; Rivlin, Patricia K; Hoy, Ronald R; Heifetz, Yael

2008-01-01

Background In both vertebrates and invertebrates, the oviduct is an epithelial tube surrounded by visceral muscles that serves as a conduit for gamete transport between the ovary and uterus. While Drosophila is a model system for tubular organ development, few studies have addressed the development of the fly's oviduct. Recent studies in Drosophila have identified mating-responsive genes and proteins whose levels in the oviduct are altered by mating. Since many of these molecules (e.g. Muscle LIM protein 84B, Coracle, Neuroglian) have known roles in the differentiation of muscle and epithelia of other organs, mating may trigger similar differentiation events in the oviduct. This led us to hypothesize that mating mediates the last stages of oviduct differentiation in which organ-specific specializations arise. Results Using electron- and confocal-microscopy we identified tissue-wide post-mating changes in the oviduct including differentiation of cellular junctions, remodeling of extracellular matrix, increased myofibril formation, and increased innervation. Analysis of once- and twice-mated females reveals that some mating-responsive proteins respond only to the first mating, while others respond to both matings. Conclusion We uncovered ultrastructural changes in the mated oviduct that are consistent with the roles that mating-responsive proteins play in muscle and epithelial differentiation elsewhere. This suggests that mating triggers the late differentiation of the oviduct. Furthermore, we suggest that mating-responsive proteins that respond only to the first mating are involved in the final maturation of the oviduct while proteins that remain responsive to later matings are also involved in maintenance and ongoing function of the oviduct. Taken together, our results establish the oviduct as an attractive system to address mechanisms that regulate the late stages of differentiation and maintenance of a tubular organ. PMID:19063748

75 FR 34049 - Magnuson-Stevens Fishery Conservation and Management Act Provisions; Fisheries of the...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-16

... limits, in season possession limit triggers, and other measures to improve management of the skate... given year, the possession limit trigger (80 percent in the wing fishery, 90 percent in the bait fishery... is exceeded by more than 5 percent, the trigger point at which the possession limit is reduced would...

Insulin-induced redistribution of GLUT4 glucose carriers in the muscle fiber. In search of GLUT4 trafficking pathways.

PubMed

Zorzano, A; Muñoz, P; Camps, M; Mora, C; Testar, X; Palacín, M

1996-01-01

Insulin rapidly stimulates glucose transport in muscle fiber. This process controls the utilization of glucose in skeletal muscle, and it is deficient in various insulin-resistant states, such as non-insulin-dependent diabetes mellitus. The effect of insulin on muscle glucose transport is mainly due to the recruitment of GLUT4 glucose carriers to the cell surface of the muscle fiber. There is increasing evidence that the recruitment of GLUT4 carriers triggered by insulin affects selective domains of sarcolemma and transverse tubules. In contrast, GLUT1 is located mainly in sarcolemma and is absent in transverse tubules, and insulin does not alter its cellular distribution in muscle fiber. The differential distribution of GLUT1 and GLUT4 in the cell surface raises new questions regarding the precise endocytic and exocytic pathways that are functional in the muscle fiber. The current view of insulin-induced GLUT4 translocation is based mainly on studies performed in adipocytes. These studies have proposed the existence of intracellular compartments of GLUT4 that respond to insulin in a highly homogeneous manner. However, studies performed in skeletal muscle have identified insulin-sensitive as well as insulin-insensitive intracellular GLUT4-containing membranes. These data open a new perspective on the dynamics of intracellular GLUT4 compartments in insulin-sensitive cells.

Divergent impact of Toll-like receptor 2 deficiency on repair mechanisms in healthy muscle versus Duchenne muscular dystrophy.

PubMed

Mojumdar, Kamalika; Giordano, Christian; Lemaire, Christian; Liang, Feng; Divangahi, Maziar; Qureshi, Salman T; Petrof, Basil J

2016-05-01

Injury to skeletal muscle, whether acute or chronic, triggers macrophage-mediated innate immunity in a manner which can be either beneficial or harmful for subsequent repair. Endogenous ligands for Toll-like receptor 2 (TLR2) are released by damaged tissues and might play an important role in activating the innate immune system following muscle injury. To test this hypothesis, we compared macrophage behaviour and muscle repair mechanisms in mice lacking TLR2 under conditions of either acute (cardiotoxin-induced) or chronic (mdx mouse genetic model of Duchenne muscular dystrophy; DMD) muscle damage. In previously healthy muscle subjected to acute damage, TLR2 deficiency reduced macrophage numbers in the muscle post-injury but did not alter the expression pattern of the prototypical macrophage polarization markers iNOS and CD206. In addition, there was abnormal persistence of necrotic fibres and impaired regeneration in TLR2-/- muscles after acute injury. In contrast, TLR2 ablation in chronically diseased muscles of mdx mice not only resulted in significantly reduced macrophage numbers but additionally modified their phenotype by shifting from inflammatory (iNOS(pos) CD206(neg) ) to more anti-inflammatory (iNOS(neg) CD206(pos) ) characteristics. This decrease in macrophage-mediated inflammation was associated with ameliorated muscle histopathology and improved force-generating capacity of the dystrophic muscle. Our results suggest that the role of TLR2 in macrophage function and skeletal muscle repair depends greatly upon the muscle injury context, and raise the possibility that inhibition of TLR2 could serve as a useful therapeutic measure in DMD. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Pilot study on quantitative assessment of muscle imbalance: differences of muscle synergies, equilibrium-point trajectories, and endpoint stiffness in normal and pathological upper-limb movements.

PubMed

Oku, Takanori; Uno, Kanna; Nishi, Tomoki; Kageyama, Masayuki; Phatiwuttipat, Pipatthana; Koba, Keitaro; Yamashita, Yuto; Murakami, Kenta; Uemura, Mitsunori; Hirai, Hiroaki; Miyazaki, Fumio; Naritomi, Hiroaki

2014-01-01

This paper proposes a novel method for assessment of muscle imbalance based on muscle synergy hypothesis and equilibrium point (EP) hypothesis of motor control. We explain in detail the method for extracting muscle synergies under the concept of agonist-antagonist (AA) muscle pairs and for estimating EP trajectories and endpoint stiffness of human upper limbs in a horizontal plane using an electromyogram. The results of applying this method to the reaching movement of one normal subject and one hemiplegic subject suggest that (1) muscle synergies (the balance among coactivation of AA muscle pairs), particularly the synergies that contributes to the angular directional kinematics of EP and the limb stiffness, are quite different between the normal subject and the hemiplegic subject; (2) the concomitant EP trajectory is also different between the normal and hemiplegic subjects, corresponding to the difference of muscle synergies; and (3) the endpoint (hand) stiffness ellipse of the hemiplegic subject becomes more elongated and orientation of the major axis rotates clockwise more than that of the normal subject. The level of motor impairment would be expected to be assessed from a comparison of these differences of muscle synergies, EP trajectories, and endpoint stiffness among normal and pathological subjects using the method.

BRANCHED FIBERS FROM OLD FAST-TWITCH DYSTROPHIC MUSCLES ARE THE SITES OF TERMINAL DAMAGE IN MUSCULAR DYSTROPHY.

PubMed

Kiriaev, Leonit; Kueh, Sindy; Morley, John W; North, Kathryn N; Houweling, Peter J; Head, Stewart I

2018-02-07

A striking pathological feature of dystrophinopathies is the presence of morphologically abnormal branched skeletal muscle fibers. The deterioration of muscle contractile function in Duchenne muscular dystrophy is accompanied by both an increase in number and complexity of these branched fibers. We propose that when number and complexity of branched fibers reaches a critical threshold, "tipping point" the branches in and of themselves are the site of contraction-induced rupture. In the present study, we use the dystrophic mdx mouse and littermate controls to study the pre-diseased dystrophic fast-twitch EDL muscle at 2-3-weeks, the peak myonecrotic phase at 6-9 weeks and finally "old" at 58-112 weeks. Using a combination of isolated muscle function contractile measurements coupled with single fiber imaging and confocal microscope imaging of cleared whole muscles we identified a distinct pathophysiology; acute fiber rupture at branch nodes, which occurs in "old" fast-twitch EDL muscle approaching the end stage of the dystrophinopathy muscle disease, where the EDL muscles are entirely composed of complexed branched fibers. This evidence supports our concept of "tipping point" where the number and extent of fiber branching reaches a level where the branching itself terminally compromises muscle function, irrespective of the absence of dystrophin.

Flipping the Metabolic Switch: Understanding and Applying Health Benefits of Fasting

PubMed Central

Anton, Stephen D.; Moehl, Keelin; Donahoo, William T.; Marosi, Krisztina; Lee, Stephanie; Mainous, Arch G.; Leeuwenburgh, Christiaan; Mattson, Mark P.

2017-01-01

Intermittent fasting (IF) is a term used to describe a variety of eating patterns in which no or few calories are consumed for time periods that can range from 12 hours to several days, on a recurring basis. Here we focus on the physiological responses of major organ systems, including the musculoskeletal system, to the onset of the metabolic switch – the point of negative energy balance at which liver glycogen stores are depleted and fatty acids are mobilized (typically beyond 12 hours after cessation of food intake). Emerging findings suggest the metabolic switch from glucose to fatty acid-derived ketones represents an evolutionarily conserved trigger point that shifts metabolism from lipid/cholesterol synthesis and fat storage to mobilization of fat through fatty acid oxidation and fatty-acid derived ketones, which serve to preserve muscle mass and function. Thus, IF regimens that induce the metabolic switch have the potential to improve body composition in overweight individuals. Moreover, IF regimens also induce the coordinated activation of signaling pathways that optimize physiological function, enhance performance, and slow aging and disease processes. Future randomized controlled IF trials should use biomarkers of the metabolic switch (e.g., plasma ketone levels) as a measure of compliance and the magnitude of negative energy balance during the fasting period. PMID:29086496

Flipping the Metabolic Switch: Understanding and Applying the Health Benefits of Fasting.

PubMed

Anton, Stephen D; Moehl, Keelin; Donahoo, William T; Marosi, Krisztina; Lee, Stephanie A; Mainous, Arch G; Leeuwenburgh, Christiaan; Mattson, Mark P

2018-02-01

Intermittent fasting (IF) is a term used to describe a variety of eating patterns in which no or few calories are consumed for time periods that can range from 12 hours to several days, on a recurring basis. This review is focused on the physiological responses of major organ systems, including the musculoskeletal system, to the onset of the metabolic switch: the point of negative energy balance at which liver glycogen stores are depleted and fatty acids are mobilized (typically beyond 12 hours after cessation of food intake). Emerging findings suggest that the metabolic switch from glucose to fatty acid-derived ketones represents an evolutionarily conserved trigger point that shifts metabolism from lipid/cholesterol synthesis and fat storage to mobilization of fat through fatty acid oxidation and fatty acid-derived ketones, which serve to preserve muscle mass and function. Thus, IF regimens that induce the metabolic switch have the potential to improve body composition in overweight individuals. Moreover, IF regimens also induce the coordinated activation of signaling pathways that optimize physiological function, enhance performance, and slow aging and disease processes. Future randomized controlled IF trials should use biomarkers of the metabolic switch (e.g., plasma ketone levels) as a measure of compliance and of the magnitude of negative energy balance during the fasting period. © 2017 The Obesity Society.

Effectiveness of myofascial trigger point manual therapy combined with a self-stretching protocol for the management of plantar heel pain: a randomized controlled trial.

PubMed

Renan-Ordine, Rômulo; Alburquerque-Sendín, Francisco; de Souza, Daiana Priscila Rodrigues; Cleland, Joshua A; Fernández-de-Las-Peñas, César

2011-02-01

A randomized controlled clinical trial. To investigate the effects of trigger point (TrP) manual therapy combined with a self-stretching program for the management of patients with plantar heel pain. Previous studies have reported that stretching of the calf musculature and the plantar fascia are effective management strategies for plantar heel pain. However, it is not known if the inclusion of soft tissue therapy can further improve the outcomes in this population. Sixty patients, 15 men and 45 women (mean ± SD age, 44 ± 10 years) with a clinical diagnosis of plantar heel pain were randomly divided into 2 groups: a self-stretching (Str) group who received a stretching protocol, and a self-stretching and soft tissue TrP manual therapy (Str-ST) group who received TrP manual interventions (TrP pressure release and neuromuscular approach) in addition to the same self-stretching protocol. The primary outcomes were physical function and bodily pain domains of the quality of life SF-36 questionnaire. Additionally, pressure pain thresholds (PPT) were assessed over the affected gastrocnemii and soleus muscles, and over the calcaneus, by an assessor blinded to the treatment allocation. Outcomes of interest were captured at baseline and at a 1-month follow-up (end of treatment period). Mixed-model ANOVAs were used to examine the effects of the interventions on each outcome, with group as the between-subjects variable and time as the within-subjects variable. The primary analysis was the group-by-time interaction. The 2 × 2 mixed-model analysis of variance (ANOVA) revealed a significant group-by-time interaction for the main outcomes of the study: physical function (P = .001) and bodily pain (P = .005); patients receiving a combination of self-stretching and TrP tissue intervention experienced a greater improvement in physical function and a greater reduction in pain, as compared to those receiving the self-stretching protocol. The mixed ANOVA also revealed significant group-by-time interactions for changes in PPT over the gastrocnemii and soleus muscles, and the calcaneus (all P<.001). Patients receiving a combination of self-stretching and TrP tissue intervention showed a greater improvement in PPT, as compared to those who received only the self-stretching protocol. This study provides evidence that the addition of TrP manual therapies to a self-stretching protocol resulted in superior short-term outcomes as compared to a self-stretching program alone in the treatment of patients with plantar heel pain. Therapy, level 1b.

Electrophysiological and neuromuscular stability of persons with chronic inflammatory demyelinating polyneuropathy.

PubMed

Gilmore, Kevin J; Allen, Matti D; Doherty, Timothy J; Kimpinski, Kurt; Rice, Charles L

2017-09-01

We assessed motor unit (MU) properties and neuromuscular stability in the tibialis anterior (TA) of chronic inflammatory demyelinating polyneuropathy (CIDP) patients using decomposition-based quantitative electromyography. Dorsiflexion strength was assessed, and surface and concentric needle electromyography were sampled from the TA. Estimates of MU numbers were derived using decomposition-based quantitative electromyography and spike-triggered averaging. Neuromuscular transmission stability was assessed from concentric needle-detected MU potentials. CIDP patients had 43% lower compound muscle action potential amplitude than controls, and despite near-maximum voluntary activation, were 37% weaker. CIDP had 27% fewer functioning MUs in the TA, and had 90% and 44% higher jiggle and jitter values, respectively compared with controls. CIDP had lower strength and compound muscle action potential values, moderately fewer numbers of MUs, and significant neuromuscular instability compared with controls. Thus, in addition to muscle atrophy, voluntary weakness is also due to limitations of peripheral neural transmission consistent with demyelination. Muscle Nerve 56: 413-420, 2017. © 2016 Wiley Periodicals, Inc.

The work of titin protein folding as a major driver in muscle contraction

PubMed Central

Eckels, Edward C.; Tapia-Rojo, Rafael; Rivas-Pardo, Jamie Andrés; Fernández, Julio M.

2018-01-01

Single molecule atomic force microscopy and magnetic tweezers experiments have demonstrated that titin Ig domains are capable of folding against a pulling force, generating mechanical work which exceeds that produced by a myosin motor. We hypothesize that upon muscle activation, formation of actomyosin crossbridges reduces the force on titin causing entropic recoil of the titin polymer and triggering the folding of the titin Ig domains. In the physiological force range of 4–15 pN under which titin operates in muscle, the folding contraction of a single Ig domain can generate 200% of the work of entropic recoil, and occurs at forces which exceed the maximum stalling force of single myosin motors. Thus titin operates like a mechanical battery storing elastic energy efficiently by unfolding Ig domains, and delivering the charge back by folding when the motors are activated during a contraction. We advance the hypothesis that titin folding and myosin activation act as inextricable partners during muscle contraction. PMID:29433413

Use of electromyography to detect muscle exhaustion in finishing barrows fed ractopamine HCl.

PubMed

Noel, J A; Broxterman, R M; McCoy, G M; Craig, J C; Phelps, K J; Burnett, D D; Vaughn, M A; Barstow, T J; O'Quinn, T G; Woodworth, J C; DeRouchey, J M; Rozell, T G; Gonzalez, J M

2016-06-01

The objectives of this study were to determine the effects of dietary ractopamine HCl (RAC) on muscle fiber characteristics and electromyography (EMG) measures of finishing barrow exhaustion when barrows were subjected to increased levels of activity. Barrows ( = 34; 92 ± 2 kg initial BW) were assigned to 1 of 2 treatments: a conventional swine finishing diet containing 0 mg/kg ractopamine HCl (CON) or a diet formulated to meet the requirements of finishing barrows fed 10 mg/kg RAC (RAC+). After 32 d on feed, barrows were individually moved around a track at 0.79 m/s until subjectively exhausted. Wireless EMG sensors were affixed to the deltoideus (DT), triceps brachii lateral head (TLH), tensor fasciae latae (TFL), and semitendinosus (ST) muscles to measure median power frequency (MdPF) and root mean square (RMS) as indicators of action potential conduction velocity and muscle fiber recruitment, respectively. After harvest, samples of each muscle were collected for fiber type, succinate dehydrogenase (SDH), and capillary density analysis. Speed was not different ( = 0.82) between treatments, but RAC+ barrows reached subjective exhaustion earlier and covered less distance than CON barrows ( < 0.01). There were no treatment × muscle interactions or treatment effects for end-point MdPF values ( > 0.29). There was a treatment × muscle interaction ( = 0.04) for end-point RMS values. The RAC diet did not change end-point RMS values in the DT or TLH ( > 0.37); however, the diet tended to decrease and increase end-point RMS in the ST and TFL, respectively ( < 0.07). There were no treatment × muscle interactions for fiber type, SDH, or capillary density measures ( > 0.10). Muscles of RAC+ barrows tended to have less type I fibers and more capillaries per fiber ( < 0.07). Type I and IIA fibers of RAC+ barrows were larger ( < 0.07). Compared with all other muscles, the ST had more ( < 0.01) type IIB fibers and larger type I, IIA, and IIX fibers ( < 0.01). Type I, IIA, and IIX fibers of the ST also contained less SDH compared with the other muscles ( < 0.01). Barrows fed a RAC diet had increased time to subjective exhaustion due to loss of active muscle fibers in the ST, possibly due to fibers being larger and less oxidative in metabolism. Size increases in type I and IIA fibers with no change in oxidative capacity could also contribute to early exhaustion of RAC+ barrows. Overall, EMG technology can measure real-time muscle fiber loss to help explain subjective exhaustion in barrows.

Triggering Factor of Strong Earthquakes and Its Prediction Verification

NASA Astrophysics Data System (ADS)

Ren, Z. Q.; Ren, S. H.

After 30 yearsS research, we have found that great earthquakes are triggered by tide- generation force of the moon. ItSs not the tide-generation force in classical view- points, but is a non-classical viewpoint tide-generation force. We call it as TGFR (Tide-Generation ForcesS Resonance). TGFR strongly depends on the tide-generation force at time of the strange astronomical points (SAP). The SAP mostly are when the moon and another celestial body are arranged with the earth along a straight line (with the same apparent right ascension or 180o difference), the other SAP are the turning points of the moonSs relatively motion to the earth. Moreover, TGFR have four different types effective areas. Our study indicates that a majority of earthquakes are triggering by the rare superimposition of TGFRsS effective areas. In China the great earthquakes in the plain area of Hebei Province, Taiwan, Yunnan Province and Sichuan province are trigger by the decompression TGFR; Other earthquakes are trig- gered by compression TGFR which are in Gansu Province, Ningxia Provinces and northwest direction of Beijing. The great earthquakes in Japan, California, southeast of Europe also are triggered by compression of the TGFR. and in the other part of the world like in Philippines, Central America countries, and West Asia, great earthquakes are triggered by decompression TGFR. We have carried out examinational immediate prediction cooperate TGFR method with other earthquake impending signals such as suggested by Professor Li Junzhi. The successful ratio is about 40%(from our fore- cast reports to the China Seismological Administration). Thus we could say the great earthquake can be predicted (include immediate earthquake prediction). Key words: imminent prediction; triggering factor; TGFR (Tide-Generation ForcesS Resonance); TGFR compression; TGFR compression zone; TGFR decompression; TGFR decom- pression zone

Effects of exercise on obesity-induced mitochondrial dysfunction in skeletal muscle

PubMed Central

Heo, Jun-Won; No, Mi-Hyun; Park, Dong-Ho; Kang, Ju-Hee; Seo, Dae Yun; Han, Jin; Neufer, P. Darrell

2017-01-01

Obesity is known to induce inhibition of glucose uptake, reduction of lipid metabolism, and progressive loss of skeletal muscle function, which are all associated with mitochondrial dysfunction in skeletal muscle. Mitochondria are dynamic organelles that regulate cellular metabolism and bioenergetics, including ATP production via oxidative phosphorylation. Due to these critical roles of mitochondria, mitochondrial dysfunction results in various diseases such as obesity and type 2 diabetes. Obesity is associated with impairment of mitochondrial function (e.g., decrease in O2 respiration and increase in oxidative stress) in skeletal muscle. The balance between mitochondrial fusion and fission is critical to maintain mitochondrial homeostasis in skeletal muscle. Obesity impairs mitochondrial dynamics, leading to an unbalance between fusion and fission by favorably shifting fission or reducing fusion proteins. Mitophagy is the catabolic process of damaged or unnecessary mitochondria. Obesity reduces mitochondrial biogenesis in skeletal muscle and increases accumulation of dysfunctional cellular organelles, suggesting that mitophagy does not work properly in obesity. Mitochondrial dysfunction and oxidative stress are reported to trigger apoptosis, and mitochondrial apoptosis is induced by obesity in skeletal muscle. It is well known that exercise is the most effective intervention to protect against obesity. Although the cellular and molecular mechanisms by which exercise protects against obesity-induced mitochondrial dysfunction in skeletal muscle are not clearly elucidated, exercise training attenuates mitochondrial dysfunction, allows mitochondria to maintain the balance between mitochondrial dynamics and mitophagy, and reduces apoptotic signaling in obese skeletal muscle. PMID:29200899

Costamere remodeling with muscle loading and unloading in healthy young men

PubMed Central

Li, Ruowei; Narici, Marco V; Erskine, Robert M; Seynnes, Olivier R; Rittweger, Jörn; Pišot, Rado; Šimunič, Boštjan; Flück, Martin

2013-01-01

Costameres are mechano-sensory sites of focal adhesion in the sarcolemma that provide a structural anchor for myofibrils. Their turnover is regulated by integrin-associated focal adhesion kinase (FAK). We hypothesized that changes in content of costamere components (beta 1 integrin, FAK, meta-vinculin, gamma-vinculin) with increased and reduced loading of human anti-gravity muscle would: (i) relate to changes in muscle size and molecular parameters of muscle size regulation [p70S6K, myosin heavy chain (MHC)1 and MHCIIA]; (ii) correspond to adjustments in activity and expression of FAK, and its negative regulator, FRNK; and (iii) reflect the temporal response to reduced and increased loading. Unloading induced a progressive decline in thickness of human vastus lateralis muscle after 8 and 34 days of bedrest (−4% and −14%, respectively; n = 9), contrasting the increase in muscle thickness after 10 and 27 days of resistance training (+5% and +13%; n = 6). Changes in muscle thickness were correlated with changes in cross-sectional area of type I muscle fibers (r = 0.66) and beta 1 integrin content (r = 0.76) at the mid-point of altered loading. Changes in meta-vinculin and FAK-pY397 content were correlated (r = 0.85) and differed, together with the changes of beta 1 integrin, MHCI, MHCII and p70S6K, between the mid- and end-point of resistance training. By contrast, costamere protein level changes did not differ between time points of bedrest. The findings emphasize the role of FAK-regulated costamere turnover in the load-dependent addition and removal of myofibrils, and argue for two phases of muscle remodeling with resistance training, which do not manifest at the macroscopic level. PMID:24010829

Effects of Cooking End-point Temperature and Muscle Part on Sensory 'Hardness' and 'Chewiness' Assessed Using Scales Presented in ISO11036:1994.

PubMed

Sasaki, Keisuke; Motoyama, Michiyo; Narita, Takumi; Chikuni, Koichi

2013-10-01

Texture and 'tenderness' in particular, is an important sensory characteristic for consumers' satisfaction of beef. Objective and detailed sensory measurements of beef texture have been needed for the evaluation and management of beef quality. This study aimed to apply the sensory scales defined in ISO11036:1994 to evaluate the texture of beef. Longissimus and Semitendinosus muscles of three Holstein steers cooked to end-point temperatures of 60°C and 72°C were subjected to sensory analyses by a sensory panel with expertise regarding the ISO11036 scales. For the sensory analysis, standard scales of 'chewiness' (9-points) and 'hardness' (7-points) were presented to the sensory panel with reference materials defined in ISO11036. As a result, both 'chewiness' and 'hardness' assessed according to the ISO11036 scales increased by increasing the cooking end-point temperature, and were different between Longissimus and Semitendinosus muscles. The sensory results were in good agreement with instrumental texture measurements. However, both texture ratings in this study were in a narrower range than the full ISO scales. For beef texture, ISO11036 scales for 'chewiness' and 'hardness' are useful for basic studies, but some alterations are needed for practical evaluation of muscle foods.

Promiscuous Actions of Small Molecule Inhibitors of the Protein Kinase D-Class IIa HDAC Axis in Striated Muscle

PubMed Central

Lemon, Douglas D.; Harrison, Brooke C.; Horn, Todd R.; Stratton, Matthew S.; Ferguson, Bradley S.; Wempe, Michael F.; McKinsey, Timothy A.

2015-01-01

PKD-mediated phosphorylation of class IIa HDACs frees the MEF2 transcription factor to activate genes that govern muscle differentiation and growth. Studies of the regulation and function of this signaling axis have involved MC1568 and Gö-6976, which are small molecule inhibitors of class IIa HDAC and PKD catalytic activity, respectively. We describe unanticipated effects of these compounds. MC1568 failed to inhibit class IIa HDAC catalytic activity in vitro, and exerted divergent effects on skeletal muscle differentiation compared to a bona fide inhibitor of these HDACs. In cardiomyocytes, Gö-6976 triggered calcium signaling and activated stress-inducible kinases. Based on these findings, caution is warranted when employing MC1568 and Gö-6976 as pharmacological tool compounds to assess functions of class IIa HDACs and PKD. PMID:25816750

GABAergic Neurons of the Central Amygdala Promote Cataplexy

PubMed Central

Agostinelli, Lindsay J.; Lowell, Bradford B.

2017-01-01

Narcolepsy is characterized by chronic sleepiness and cataplexy—sudden muscle paralysis triggered by strong, positive emotions. This condition is caused by a lack of orexin (hypocretin) signaling, but little is known about the neural mechanisms that mediate cataplexy. The amygdala regulates responses to rewarding stimuli and contains neurons active during cataplexy. In addition, lesions of the amygdala reduce cataplexy. Because GABAergic neurons of the central nucleus of the amygdala (CeA) target brainstem regions known to regulate muscle tone, we hypothesized that these cells promote emotion-triggered cataplexy. We injected adeno-associated viral vectors coding for Cre-dependent DREADDs or a control vector into the CeA of orexin knock-out mice crossed with vGAT-Cre mice, resulting in selective expression of the excitatory hM3 receptor or the inhibitory hM4 receptor in GABAergic neurons of the CeA. We measured sleep/wake behavior and cataplexy after injection of saline or the hM3/hM4 ligand clozapine-N-oxide (CNO) under baseline conditions and under conditions that should elicit positive emotions. In mice expressing hM3, CNO approximately doubled the amount of cataplexy in the first 3 h after dosing under baseline conditions. Rewarding stimuli (chocolate or running wheels) also increased cataplexy, but CNO produced no further increase. In mice expressing hM4, CNO reduced cataplexy in the presence of chocolate or running wheels. These results demonstrate that GABAergic neurons of the CeA are sufficient and necessary for the production of cataplexy in mice, and they likely are a key part of the mechanism through which positive emotions trigger cataplexy. SIGNIFICANCE STATEMENT Cataplexy is one of the major symptoms of narcolepsy, but little is known about how strong, positive emotions trigger these episodes of muscle paralysis. Prior research shows that amygdala neurons are active during cataplexy and cataplexy is reduced by lesions of the amygdala. We found that cataplexy is substantially increased by selective activation of GABAergic neurons in the central nucleus of the amygdala (CeA). We also demonstrate that inhibition of these neurons reduces reward-promoted cataplexy. These results build upon prior work to establish the CeA as a crucial element in the neural mechanisms of cataplexy. These results demonstrate the importance of the CeA in regulating responses to rewarding stimuli, shedding light on the broader neurobiology of emotions and motor control. PMID:28235898

Fracture of the clavicle and second rib: an indirect injury from tricep dips.

PubMed

Malavolta, Eduardo A; Assunção, Jorge H; Gracitelli, Mauro E; Lobo, Frederico L; Ferreira Neto, Arnaldo A

2016-01-01

Due to the recent rise in the interest in strength training, an increment in the number of lesions is expected, whether of the tendons, muscles, or bones. We describe a case of fracture involving the middle third of the clavicle and the second rib in a low-demand weightlifter. The fractures occurred suddenly while performing a triceps dips exercise, and the patient had no previous symptoms. He was treated conservatively and was able to return to sports six months later. To our knowledge, this is the first study describing the association of these fractures triggered by a single event of muscle contraction.

Axonal regeneration through acellular muscle grafts

PubMed Central

HALL, SUSAN

1997-01-01

The management of peripheral nerve injury remains a major clinical problem. Progress in this field will almost certainly depend upon manipulating the pathophysiological processes which are triggered by traumatic injuries. One of the most important determinants of functional outcome after the reconstruction of a transected peripheral nerve is the length of the gap between proximal and distal nerve stumps. Long defects (> 2 cm) must be bridged by a suitable conduit in order to support axonal regrowth. This review examines the cellular and acellular elements which facilitate axonal regrowth and the use of acellular muscle grafts in the repair of injuries in the peripheral nervous system. PMID:9034882

Prostaglandin E2 is essential for efficacious skeletal muscle stem-cell function, augmenting regeneration and strength.

PubMed

Ho, Andrew T V; Palla, Adelaida R; Blake, Matthew R; Yucel, Nora D; Wang, Yu Xin; Magnusson, Klas E G; Holbrook, Colin A; Kraft, Peggy E; Delp, Scott L; Blau, Helen M

2017-06-27

Skeletal muscles harbor quiescent muscle-specific stem cells (MuSCs) capable of tissue regeneration throughout life. Muscle injury precipitates a complex inflammatory response in which a multiplicity of cell types, cytokines, and growth factors participate. Here we show that Prostaglandin E2 (PGE2) is an inflammatory cytokine that directly targets MuSCs via the EP4 receptor, leading to MuSC expansion. An acute treatment with PGE2 suffices to robustly augment muscle regeneration by either endogenous or transplanted MuSCs. Loss of PGE2 signaling by specific genetic ablation of the EP4 receptor in MuSCs impairs regeneration, leading to decreased muscle force. Inhibition of PGE2 production through nonsteroidal anti-inflammatory drug (NSAID) administration just after injury similarly hinders regeneration and compromises muscle strength. Mechanistically, the PGE2 EP4 interaction causes MuSC expansion by triggering a cAMP/phosphoCREB pathway that activates the proliferation-inducing transcription factor, Nurr1 Our findings reveal that loss of PGE2 signaling to MuSCs during recovery from injury impedes muscle repair and strength. Through such gain- or loss-of-function experiments, we found that PGE2 signaling acts as a rheostat for muscle stem-cell function. Decreased PGE2 signaling due to NSAIDs or increased PGE2 due to exogenous delivery dictates MuSC function, which determines the outcome of regeneration. The markedly enhanced and accelerated repair of damaged muscles following intramuscular delivery of PGE2 suggests a previously unrecognized indication for this therapeutic agent.

Oxidative stress exaggerates skeletal muscle contraction-evoked reflex sympathoexcitation in rats with hypertension induced by angiotensin II.

PubMed

Koba, Satoshi; Watanabe, Ryosuke; Kano, Naoko; Watanabe, Tatsuo

2013-01-01

Muscle contraction stimulates thin fiber muscle afferents and evokes reflex sympathoexcitation. In hypertension, this reflex is exaggerated. ANG II, which is elevated in hypertension, has been reported to trigger the production of superoxide and other reactive oxygen species. In the present study, we tested the hypothesis that increased ANG II in hypertension exaggerates skeletal muscle contraction-evoked reflex sympathoexcitation by inducing oxidative stress in the muscle. In rats, subcutaneous infusion of ANG II at 450 ng·kg(-1)·min(-1) for 14 days significantly (P < 0.05) elevated blood pressure compared with sham-operated (sham) rats. Electrically induced 30-s hindlimb muscle contraction in decerebrate rats with hypertension evoked larger renal sympathoexcitatory and pressor responses [+1,173 ± 212 arbitrary units (AU) and +35 ± 5 mmHg, n = 10] compared with sham normotensive rats (+419 ± 103 AU and +13 ± 2 mmHg, n = 11). Tempol, a SOD mimetic, injected intra-arterially into the hindlimb circulation significantly reduced responses in hypertensive rats, whereas this compound had no effect on responses in sham rats. Tiron, another SOD mimetic, also significantly reduced reflex renal sympathetic and pressor responses in a subset of hypertensive rats (n = 10). Generation of muscle superoxide, as evaluated by dihydroethidium staining, was increased in hypertensive rats. RT-PCR and immunoblot experiments showed that mRNA and protein for gp91(phox), a NADPH oxidase subunit, in skeletal muscle tissue were upregulated in hypertensive rats. Taken together, hese results suggest that increased ANG II in hypertension induces oxidative stress in skeletal muscle, thereby exaggerating the muscle reflex.

AMPLITUDE DISCRIMINATOR HAVING SEPARATE TRIGGERING AND RECOVERY CONTROLS UTILIZING AUTOMATIC TRIGGERING

DOEpatents

Chase, R.L.

1962-01-23

A transistorized amplitude discriminator circuit is described in which the initial triggering sensitivity and the recovery threshold are separately adjustable in a convenient manner. The discriminator is provided with two independent bias components, one of which is for circuit hysteresis (recovery) and one of which is for trigger threshold level. A switching circuit is provided to remove the second bias component upon activation of the trigger so that the recovery threshold is always at the point where the trailing edge of the input signal pulse goes through zero or other desired value. (AEC)

Onset of oviposition triggers abrupt reduction in migratory flight behavior and flight muscle in the female beet webworm, Loxostege sticticalis

USDA-ARS?s Scientific Manuscript database

Flight and reproduction are usually considered as two life history traits that compete for resources in a migratory insect. The beet webworm, Loxostege sticticalis L., manages the costs of migratory flight and reproduction through a trade-off in timing of these two life history traits, where migrato...

Role of the medial prefrontal cortex in cataplexy.

PubMed

Oishi, Yo; Williams, Rhiannan H; Agostinelli, Lindsay; Arrigoni, Elda; Fuller, Patrick M; Mochizuki, Takatoshi; Saper, Clifford B; Scammell, Thomas E

2013-06-05

Narcolepsy is characterized by chronic sleepiness and cataplexy, episodes of profound muscle weakness that are often triggered by strong, positive emotions. Narcolepsy with cataplexy is caused by a loss of orexin (also known as hypocretin) signaling, but almost nothing is known about the neural mechanisms through which positive emotions trigger cataplexy. Using orexin knock-out mice as a model of narcolepsy, we found that palatable foods, especially chocolate, markedly increased cataplexy and activated neurons in the medial prefrontal cortex (mPFC). Reversible suppression of mPFC activity using an engineered chloride channel substantially reduced cataplexy induced by chocolate but did not affect spontaneous cataplexy. In addition, neurons in the mPFC innervated parts of the amygdala and lateral hypothalamus that contain neurons active during cataplexy and that innervate brainstem regions known to regulate motor tone. These observations indicate that the mPFC is a critical site through which positive emotions trigger cataplexy.

Role of the medial prefrontal cortex in cataplexy

PubMed Central

Oishi, Yo; Williams, Rhiannan H.; Agostinelli, Lindsay; Arrigoni, Elda; Fuller, Patrick M.; Mochizuki, Takatoshi; Saper, Clifford B.; Scammell, Thomas E.

2013-01-01

Narcolepsy is characterized by chronic sleepiness and cataplexy - episodes of profound muscle weakness that are often triggered by strong, positive emotions. Narcolepsy with cataplexy is caused by a loss of orexin (also known as hypocretin) signaling, but almost nothing is known about the neural mechanisms through which positive emotions trigger cataplexy. Using orexin knockout mice as a model of narcolepsy, we found that palatable foods, especially chocolate, markedly increased cataplexy and activated neurons in the medial prefrontal cortex (mPFC). Reversible suppression of mPFC activity using an engineered chloride channel substantially reduced cataplexy induced by chocolate but did not affect spontaneous cataplexy. In addition, neurons in the mPFC innervated parts of the amygdala and lateral hypothalamus that contain neurons active during cataplexy, and that innervate brainstem regions known to regulate motor tone. These observations indicate that the mPFC is a critical site through which positive emotions trigger cataplexy. PMID:23739971

Knee joint contact mechanics during downhill gait and its relationship with varus/valgus motion and muscle strength in patients with knee osteoarthritis.

PubMed

Farrokhi, Shawn; Voycheck, Carrie A; Gustafson, Jonathan A; Fitzgerald, G Kelley; Tashman, Scott

2016-01-01

The objective of this exploratory study was to evaluate tibiofemoral joint contact point excursions and velocities during downhill gait and assess the relationship between tibiofemoral joint contact mechanics with frontal-plane knee joint motion and lower extremity muscle weakness in patients with knee osteoarthritis (OA). Dynamic stereo X-ray was used to quantify tibiofemoral joint contact mechanics and frontal-plane motion during the loading response phase of downhill gait in 11 patients with knee OA and 11 control volunteers. Quantitative testing of the quadriceps and the hip abductor muscles was also performed. Patients with knee OA demonstrated larger medial/lateral joint contact point excursions (p < 0.02) and greater heel-strike joint contact point velocities (p < 0.05) for the medial and lateral compartments compared to the control group. The peak medial/lateral joint contact point velocity of the medial compartment was also greater for patients with knee OA compared to their control counterparts (p = 0.02). Additionally, patients with knee OA demonstrated significantly increased frontal-plane varus motion excursions (p < 0.01) and greater quadriceps and hip abductor muscle weakness (p = 0.03). In general, increased joint contact point excursions and velocities in patients with knee OA were linearly associated with greater frontal-plane varus motion excursions (p < 0.04) but not with quadriceps or hip abductor strength. Altered contact mechanics in patients with knee OA may be related to compromised frontal-plane joint stability but not with deficits in muscle strength.

The combined action of a passive exoskeleton and an EMG-controlled neuroprosthesis for upper limb stroke rehabilitation: First results of the RETRAINER project.

PubMed

Ambrosini, E; Ferrante, S; Zajc, J; Bulgheroni, M; Baccinelli, W; d'Amico, E; Schauer, T; Wiesener, C; Russold, M; Gfoehler, M; Puchinger, M; Weber, M; Becker, S; Krakow, K; Rossini, M; Proserpio, D; Gasperini, G; Molteni, F; Ferrigno, G; Pedrocchi, A

2017-07-01

The combined use of Functional Electrical Stimulation (FES) and robotic technologies is advocated to improve rehabilitation outcomes after stroke. This work describes an arm rehabilitation system developed within the European project RETRAINER. The system consists of a passive 4-degrees-of-freedom exoskeleton equipped with springs to provide gravity compensation and electromagnetic brakes to hold target positions. FES is integrated in the system to provide additional support to the most impaired muscles. FES is triggered based on the volitional EMG signal of the same stimulated muscle; in order to encourage the active involvement of the patient the volitional EMG is also monitored throughout the task execution and based on it a happy or sad emoji is visualized at the end of each task. The control interface control of the system provides a GUI and multiple software tools to organize rehabilitation exercises and monitor rehabilitation progress. The functionality and the usability of the system was evaluated on four stroke patients. All patients were able to use the system and judged positively its wearability and the provided support. They were able to trigger the stimulation based on their residual muscle activity and provided different levels of active involvement in the exercise, in agreement with their level of impairment. A randomized controlled trial aimed at evaluating the effectiveness of the RETRAINER system to improve arm function after stroke is currently ongoing.

Neuropeptide Secreted from a Pacemaker Activates Neurons to Control a Rhythmic Behavior

PubMed Central

Wang, Han; Girskis, Kelly; Janssen, Tom; Chan, Jason P.; Dasgupta, Krishnakali; Knowles, James A.; Schoofs, Liliane; Sieburth, Derek

2013-01-01

Summary Background Rhythmic behaviors are driven by endogenous biological clocks in pacemakers, which must reliably transmit timing information to target tissues that execute rhythmic outputs. During the defecation motor program in C. elegans, calcium oscillations in the pacemaker (intestine), which occur about every 50 seconds, trigger rhythmic enteric muscle contractions through downstream GABAergic neurons that innervate enteric muscles. However, the identity of the timing signal released by the pacemaker and the mechanism underlying the delivery of timing information to the GABAergic neurons are unknown. Results Here we show that a neuropeptide-like protein (NLP-40) released by the pacemaker triggers a single rapid calcium transient in the GABAergic neurons during each defecation cycle. We find that mutants lacking nlp-40 have normal pacemaker function, but lack enteric muscle contractions. NLP-40 undergoes calcium-dependent release that is mediated by the calcium sensor, SNT-2/synaptotagmin. We identify AEX-2, the G protein-coupled receptor on the GABAergic neurons, as the receptor of NLP-40. Functional calcium imaging reveals that NLP-40 and AEX-2/GPCR are both necessary for rhythmic activation of these neurons. Furthermore, acute application of synthetic NLP-40-derived peptide depolarizes the GABAergic neurons in vivo. Conclusions Our results show that NLP-40 carries the timing information from the pacemaker via calcium-dependent release and delivers it to the GABAergic neurons by instructing their activation. Thus, we propose that rhythmic release of neuropeptides can deliver temporal information from pacemakers to downstream neurons to execute rhythmic behaviors. PMID:23583549

Trunk muscle recruitment patterns in simulated precrash events.

PubMed

Ólafsdóttir, Jóna Marín; Fice, Jason B; Mang, Daniel W H; Brolin, Karin; Davidsson, Johan; Blouin, Jean-Sébastien; Siegmund, Gunter P

2018-02-28

To quantify trunk muscle activation levels during whole body accelerations that simulate precrash events in multiple directions and to identify recruitment patterns for the development of active human body models. Four subjects (1 female, 3 males) were accelerated at 0.55 g (net Δv = 4.0 m/s) in 8 directions while seated on a sled-mounted car seat to simulate a precrash pulse. Electromyographic (EMG) activity in 4 trunk muscles was measured using wire electrodes inserted into the left rectus abdominis, internal oblique, iliocostalis, and multifidus muscles at the L2-L3 level. Muscle activity evoked by the perturbations was normalized by each muscle's isometric maximum voluntary contraction (MVC) activity. Spatial tuning curves were plotted at 150, 300, and 600 ms after acceleration onset. EMG activity remained below 40% MVC for the three time points for most directions. At the 150- and 300 ms time points, the highest EMG amplitudes were observed during perturbations to the left (-90°) and left rearward (-135°). EMG activity diminished by 600 ms for the anterior muscles, but not for the posterior muscles. These preliminary results suggest that trunk muscle activity may be directionally tuned at the acceleration level tested here. Although data from more subjects are needed, these preliminary data support the development of modeled trunk muscle recruitment strategies in active human body models that predict occupant responses in precrash scenarios.

Triggerable electro-optic amplitude modulator bias stabilizer for integrated optical devices

DOEpatents

Conder, A.D.; Haigh, R.E.; Hugenberg, K.F.

1995-09-26

An improved Mach-Zehnder integrated optical electro-optic modulator is achieved by application and incorporation of a DC bias box containing a laser synchronized trigger circuit, a DC ramp and hold circuit, a modulator transfer function negative peak detector circuit, and an adjustable delay circuit. The DC bias box ramps the DC bias along the transfer function curve to any desired phase or point of operation at which point the RF modulation takes place. 7 figs.

Triggerable electro-optic amplitude modulator bias stabilizer for integrated optical devices

DOEpatents

Conder, Alan D.; Haigh, Ronald E.; Hugenberg, Keith F.

1995-01-01

An improved Mach-Zehnder integrated optical electro-optic modulator is achieved by application and incorporation of a DC bias box containing a laser synchronized trigger circuit, a DC ramp and hold circuit, a modulator transfer function negative peak detector circuit, and an adjustable delay circuit. The DC bias box ramps the DC bias along the transfer function curve to any desired phase or point of operation at which point the RF modulation takes place.

Additional Effect of Static Ultrasound and Diadynamic Currents on Myofascial Trigger Points in a Manual Therapy Program for Patients With Chronic Neck Pain: A Randomized Clinical Trial.

PubMed

Dibai-Filho, Almir Vieira; de Oliveira, Alessandra Kelly; Girasol, Carlos Eduardo; Dias, Fabiana Rodrigues Cancio; Guirro, Rinaldo Roberto de Jesus

2017-04-01

To assess the additional effect of static ultrasound and diadynamic currents on myofascial trigger points in a manual therapy program to treat individuals with chronic neck pain. A single-blind randomized trial was conducted. Both men and women, between ages 18 and 45, with chronic neck pain and active myofascial trigger points in the upper trapezius were included in the study. Subjects were assigned to 3 different groups: group 1 (n = 20) was treated with manual therapy; group 2 (n = 20) was treated with manual therapy and static ultrasound; group 3 (n = 20) was treated with manual therapy and diadynamic currents. Individuals were assessed before the first treatment session, 48 hours after the first treatment session, 48 hours after the tenth treatment session, and 4 weeks after the last session. There was no group-versus-time interaction for Numeric Rating Scale, Neck Disability Index, Pain-Related Self-Statement Scale, pressure pain threshold, cervical range of motion, and skin temperature (F-value range, 0.089-1.961; P-value range, 0.106-0.977). Moreover, we found no differences between groups regarding electromyographic activity (P > 0.05). The use of static ultrasound or diadynamic currents on myofascial trigger points in upper trapezius associated with a manual therapy program did not generate greater benefits than manual therapy alone.

Tubular localization of silent calcium channels in crustacean skeletal muscle fibers.

PubMed

Monterrubio, J; Ortiz, G; Orkand, P M; Zuazaga, C

2002-01-01

Ca2+-induced Ca2+ release (CICR) in the superficial abdominal flexor muscle of the crustacean Atya lanipes appears to be mediated by a local control mechanism similar to that of vertebrate cardiac muscle, but with an unusually high gain. Thus, Ca2+ influx increases sufficiently the local concentration of Ca2+ in the immediate vicinity of the sarcoplasmic reticulum Ca2+ release channels to trigger the highly amplified release of Ca2+ required for contraction, but is too low to generate a macroscopic inward current (i.e., the Ca2+ channels are silent). To determine the localization of the silent Ca2+ Channels, the mechanical, electrophysiological and ultrastructural properties of the muscle were examined before and after formamide treatment, a procedure that produces the disruption of transverse tubules of striated muscle. We found that tubular disruption decreased tension generation by about 90%; reduced inward current (measured as Vmax, the maximum rate of rise of Sr2+ action potentials) by about 80%; and decreased membrane capacitance by about 77%. The results suggest that ca. 80% of the silent Ca2+ channels are located in the tubular system. Thus, these studies provide further evidence to support the local control mechanism of CICR in crustacean skeletal muscle.

Type 1 Inositol (1,4,5)-Trisphosphate Receptor Activates Ryanodine Receptor 1 to Mediate Calcium Spark Signaling in Adult Mammalian Skeletal Muscle*♦

PubMed Central

Tjondrokoesoemo, Andoria; Li, Na; Lin, Pei-Hui; Pan, Zui; Ferrante, Christopher J.; Shirokova, Natalia; Brotto, Marco; Weisleder, Noah; Ma, Jianjie

2013-01-01

Functional coupling between inositol (1,4,5)-trisphosphate receptor (IP3R) and ryanodine receptor (RyR) represents a critical component of intracellular Ca2+ signaling in many excitable cells; however, the role of this mechanism in skeletal muscle remains elusive. In skeletal muscle, RyR-mediated Ca2+ sparks are suppressed in resting conditions, whereas application of transient osmotic stress can trigger activation of Ca2+ sparks that are restricted to the periphery of the fiber. Here we show that onset of these spatially confined Ca2+ sparks involves interaction between activation of IP3R and RyR near the sarcolemmal membrane. Pharmacological prevention of IP3 production or inhibition of IP3R channel activity abolishes stress-induced Ca2+ sparks in skeletal muscle. Although genetic ablation of the type 2 IP3R does not appear to affect Ca2+ sparks in skeletal muscle, specific silencing of the type 1 IP3R leads to ablation of stress-induced Ca2+ sparks. Our data indicate that membrane-delimited signaling involving cross-talk between IP3R1 and RyR1 contributes to Ca2+ spark activation in skeletal muscle. PMID:23223241

Asymmetry of neck motion and activation of the cervical paraspinal muscles during prone neck extension in subjects with unilateral posterior neck pain.

PubMed

Park, Kyue-Nam; Kwon, Oh-Yun; Kim, Su-Jung; Kim, Si-Hyun

2017-01-01

Although unilateral posterior neck pain (UPNP) is more prevalent than central neck pain, little is known about how UPNP affects neck motion and the muscle activation pattern during prone neck extension. To investigate whether deviation in neck motion and asymmetry of activation of the bilateral cervical paraspinal muscles occur during prone neck extension in subjects with UPNP compared to subjects without UPNP. This study recruited 20 subjects with UPNP and 20 age- and sex-matched control subjects without such pain. Neck motion and muscle onset time during prone neck extension were measured using a three-dimensional motion-analysis system and surface electromyography. The deviation during prone neck extension was greater in the UPNP group than in the controls (p < 0.05). Compared with the controls, cervical extensor muscle activation in the UPNP group was significantly delayed on the painful side during prone neck extension (p < 0.05). Subjects with UPNP showed greater asymmetry of neck motion and muscle activation during prone neck extension compared with the controls. This suggests that UPNP has specific effects on neck motion asymmetry and the functions of the cervical extensors, triggering a need for specific evaluation and exercises in the management of patients with UPNP.

Voluntary ambulation using voluntary upper limb muscle activity and Hybrid Assistive Limb® (HAL®) in a patient with complete paraplegia due to chronic spinal cord injury: A case report.

PubMed

Shimizu, Yukiyo; Kadone, Hideki; Kubota, Shigeki; Suzuki, Kenji; Saotome, Kousaku; Ueno, Tomoyuki; Abe, Tetsuya; Marushima, Aiki; Watanabe, Hiroki; Endo, Ayumu; Tsurumi, Kazue; Ishimoto, Ryu; Matsushita, Akira; Koda, Masao; Matsumura, Akira; Sankai, Yoshiyuki; Hada, Yasushi; Yamazaki, Masashi

2018-01-19

We sought to describe our experience with the Hybrid Assistive Limb® (HAL®) for active knee extension and voluntary ambulation with remaining muscle activity in a patient with complete paraplegia after spinal cord injury. A 30-year-old man with complete paraplegia used the HAL® for 1 month (10 sessions) using his remaining muscle activity, including hip flexor and upper limb activity. Electromyography was used to evaluate muscle activity of the gluteus maximus, tensor fascia lata, quadriceps femoris, and hamstring muscles in synchronization with the Vicon motion capture system. A HAL® session included a knee extension session with the hip flexor and voluntary gait with upper limb activity. After using the HAL® for one month, the patient's manual muscle hip flexor scores improved from 1/5 to 2/5 for the right and from 2/5 to 3/5 for the left knee, and from 0/5 to 1/5 for the extension of both knees. Knee extension sessions with HAL®, and hip flexor and upper-limb-triggered HAL® ambulation seem a safe and feasible option in a patient with complete paraplegia due to spinal cord injury.

Motor plan differs for young and older adults during similar movements.

PubMed

Casamento-Moran, Agostina; Chen, Yen-Ting; Lodha, Neha; Yacoubi, Basma; Christou, Evangelos A

2017-04-01

Older adults exhibit altered activation of the agonist and antagonist muscles during goal-directed movements compared with young adults. However, it remains unclear whether the differential activation of the antagonistic muscles in older adults results from an impaired motor plan or an altered ability of the muscle to contract. The purpose of this study, therefore, was to determine whether the motor plan differs for young and older adults. Ten young (26.1 ± 4.3 yr, 4 women) and 16 older adults (71.9 ± 6.9 yr, 9 women) participated in the study. Participants performed 100 trials of fast goal directed movements with ankle dorsiflexion while we recorded the electromyographic activity of the primary agonist (tibialis anterior; TA) and antagonist (soleus; SOL) muscles. From those 100 trials we selected 5 trials in each of 3 movement end-point categories (fast, accurate, and slow). We investigated age-associated differences in the motor plan by quantifying the individual activity and coordination of the agonist and antagonist muscles. During similar movement end points, older adults exhibited similar activation of the agonist (TA) and antagonist (SOL) muscles compared with young adults. In addition, the coordination of the agonist and antagonist muscles (TA and SOL) was different between the two age groups. Specifically, older adults exhibited lower TA-SOL overlap ( F 1,23 = 41.2, P < 0.001) and greater TA-SOL peak EMG delay ( F 1,25 = 35.5, P < 0.001). This finding suggests that although subjects in both age groups displayed similar movement end points, they exhibited a different motor plan, as demonstrated by altered coordination between the agonist and antagonist muscles. NEW & NOTEWORTHY We aimed to determine whether the altered activation of muscles in older adults compared with young adults during fast goal-directed movements is related to an altered motor plan. For matched movements, there were differences in the coordination of antagonistic muscles but no differences in the individual activation of muscles. We provide novel evidence that the differential activation of muscles in older adults is related to an altered motor plan. Copyright © 2017 the American Physiological Society.

Properties of primary motor cortex output to hindlimb muscles in the macaque monkey

PubMed Central

Hudson, Heather M.; Griffin, Darcy M.; Belhaj-Saïf, Abderraouf

2014-01-01

The cortical control of forelimb motor function has been studied extensively, especially in the primate. In contrast, cortical control of the hindlimb has been relatively neglected. This study assessed the output properties of the primary motor cortex (M1) hindlimb representation in terms of the sign, latency, magnitude, and distribution of effects in stimulus-triggered averages (StTAs) of electromyography (EMG) activity recorded from 19 muscles, including hip, knee, ankle, digit, and intrinsic foot muscles, during a push-pull task compared with data reported previously on the forelimb. StTAs (15, 30, and 60 μA at 15 Hz) of EMG activity were computed at 317 putative layer V sites in two rhesus macaques. Poststimulus facilitation (PStF) was distributed equally between distal and proximal muscles, whereas poststimulus suppression (PStS) was more common in distal muscles than proximal muscles (51/49%, respectively, for PStF; 72/28%, respectively, for PStS) at 30 μA. Mean PStF and PStS onset latency generally increased the more distal the joint of a muscle's action. Most significantly, the average magnitude of hindlimb poststimulus effects was considerably weaker than the average magnitude of effects from forelimb M1. In addition, forelimb PStF magnitude increased consistently from proximal to distal joints, whereas hindlimb PStF magnitude was similar at all joints except the intrinsic foot muscles, which had a magnitude of approximately double that of all of the other muscles. The results suggest a greater monosynaptic input to forelimb compared with hindlimb motoneurons, as well as a more direct synaptic linkage for the intrinsic foot muscles compared with the other hindlimb muscles. PMID:25411454

Loss of the Inducible Hsp70 Delays the Inflammatory Response to Skeletal Muscle Injury and Severely Impairs Muscle Regeneration

PubMed Central

Howard, Travis M.; Ahn, Bumsoo; Ferreira, Leonardo F.

2013-01-01

Skeletal muscle regeneration following injury is a highly coordinated process that involves transient muscle inflammation, removal of necrotic cellular debris and subsequent replacement of damaged myofibers through secondary myogenesis. However, the molecular mechanisms which coordinate these events are only beginning to be defined. In the current study we demonstrate that Heat shock protein 70 (Hsp70) is increased following muscle injury, and is necessary for the normal sequence of events following severe injury induced by cardiotoxin, and physiological injury induced by modified muscle use. Indeed, Hsp70 ablated mice showed a significantly delayed inflammatory response to muscle injury induced by cardiotoxin, with nearly undetected levels of both neutrophil and macrophage markers 24 hours post-injury. At later time points, Hsp70 ablated mice showed sustained muscle inflammation and necrosis, calcium deposition and impaired fiber regeneration that persisted several weeks post-injury. Through rescue experiments reintroducing Hsp70 intracellular expression plasmids into muscles of Hsp70 ablated mice either prior to injury or post-injury, we confirm that Hsp70 optimally promotes muscle regeneration when expressed during both the inflammatory phase that predominates in the first four days following severe injury and the regenerative phase that predominates thereafter. Additional rescue experiments reintroducing Hsp70 protein into the extracellular microenvironment of injured muscles at the onset of injury provides further evidence that Hsp70 released from damaged muscle may drive the early inflammatory response to injury. Importantly, following induction of physiological injury through muscle reloading following a period of muscle disuse, reduced inflammation in 3-day reloaded muscles of Hsp70 ablated mice was associated with preservation of myofibers, and increased muscle force production at later time points compared to WT. Collectively our findings indicate that depending on the nature and severity of muscle injury, therapeutics which differentially target both intracellular and extracellular localized Hsp70 may optimally preserve muscle tissue and promote muscle functional recovery. PMID:23626847

Estimation of skeletal muscle interstitial adenosine during forearm dynamic exercise in humans

NASA Technical Reports Server (NTRS)

Costa, F.; Heusinkveld, J.; Ballog, R.; Davis, S.; Biaggioni, I.

2000-01-01

It has been proposed that adenosine is a metabolic signal that triggers activation of muscle afferents involved in the exercise pressor reflex. Furthermore, exogenous adenosine induces sympathetic activation that mimics the exercise pressor reflex, and blockade of adenosine receptors inhibits sympathetic activation induced by exercise. Thus, we hypothesize that adenosine is released locally by the muscle during exercise. We used microdialysis probes, placed in the flexor digitorium superficialis muscle, to estimate muscle interstitial adenosine levels in humans. We estimated resting in vivo muscle interstitial adenosine concentrations (0.292+/-0.058 micromol/L, n=4) by perfusing increasing concentrations of adenosine to determine the gradient produced in the dialysate. Muscle interstitial adenosine concentrations increased from 0.23+/-0.04 to 0.82+/-0.14 micromol/L (n=14, P<0.001) during intermittent dynamic exercise at 50% of maximal voluntary contraction. Lactate increased from 0.8+/-0.1 to 2.3+/-0.3 mmol/L (P<0.001). Lower intensity (15% maximal voluntary contraction) intermittent dynamic exercise increased adenosine concentrations from 0.104+/-0.02 to 0.42+/-0.16 micromol/L (n=7). The addition of ischemia to this low level of exercise produced a greater increase in adenosine (from 0.095+/-0.02 to 0.48+/-0.2 micromol/L) compared with nonischemic exercise (0. 095+/-0.02 to 0.25+/-0.12 micromol/L). These results indicate that microdialysis is useful in estimating adenosine concentrations and in reflecting changes in muscle interstitial adenosine during dynamic exercise in humans.

Knee Joint Contact Mechanics during Downhill Gait and its Relationship with Varus/Valgus Motion and Muscle Strength in Patients with Knee Osteoarthritis

PubMed Central

Farrokhi, Shawn; Voycheck, Carrie A.; Gustafson, Jonathan A.; Fitzgerald, G. Kelley; Tashman, Scott

2015-01-01

Objective The objective of this exploratory study was to evaluate tibiofemoral joint contact point excursions and velocities during downhill gait and assess the relationship between tibiofemoral joint contact mechanics with frontal-plane knee joint motion and lower extremity muscle weakness in patients with knee osteoarthritis (OA). Methods Dynamic stereo X-ray was used to quantify tibiofemoral joint contact mechanics and frontal-plane motion during the loading response phase of downhill gait in 11 patients with knee OA and 11 control volunteers. Quantitative testing of the quadriceps and the hip abductor muscles was also performed. Group differences in contact mechanics and frontal-plane motion excursions were compared using analysis of covariance with adjustments for body mass index. Differences in strength were compared using independent sample t-tests. Additionally, linear associations between contact mechanics with frontal-plane knee motion and muscle strength were evaluated using Pearson's correlation coefficients. Results Patients with knee OA demonstrated larger medial/lateral joint contact point excursions (p<0.02) and greater heel-strike joint contact point velocities (p<0.05) for the medial and lateral compartments compared to the control group. The peak medial/lateral joint contact point velocity of the medial compartment was also greater for patients with knee OA compared to their control counterparts (p=0.02). Additionally, patients with knee OA demonstrated significantly increased frontal-plane varus motion excursions (p<0.01) and greater quadriceps and hip abductor muscle weakness (p=0.03). In general, increased joint contact point excursions and velocities in patients with knee OA were linearly associated with greater frontal-plane varus motion excursions (p<0.04) but not with quadriceps or hip abductor strength. Conclusion Altered contact mechanics in patients with knee OA may be related to compromised frontal-plane joint stability but not with deficits in muscle strength. PMID:27030846

Association of Chronic Pelvic Pain and Endometriosis With Signs of Sensitization and Myofascial Pain

PubMed Central

Stratton, Pamela; Khachikyan, Izabella; Sinaii, Ninet; Ortiz, Robin; Shah, Jay

2014-01-01

Objective To evaluate sensitization, myofascial trigger points, and quality of life in women with chronic pelvic pain with and without endometriosis. Methods A cross-sectional prospective study of women aged 18 to 50 with pain suggestive of endometriosis and healthy, pain-free volunteers without history of endometriosis. Patients underwent a physiatric neuro-musculoskeletal assessment of clinical signs of sensitization and myofascial trigger points in the abdominopelvic region. Pain symptoms, psychosocial, and quality-of-life measures were also assessed. All pain participants underwent laparoscopic excision of suspicious lesions to confirm endometriosis diagnosis by histologic evaluation. Results Patients included 18 with current, biopsy-proven endometriosis, 11 with pain only, and 20 healthy volunteers. The prevalence of sensitization as measured by regional allodynia and hyperalgesia was similar in both pain groups (83% and 82%) but much lower among healthy volunteers (15%, p<0.001). Nearly all women with pain had myofascial trigger points (94% and 91%). Adjusting for study group, those with high anxiety (OR=1.05, 95% CI:1.004–1.099; p=0.031) and depression (OR=1.06, 95% CI:1.005–1.113; p=0.032) scores were more likely to have sensitization. Pain patients with any history of endometriosis had the highest proportion of sensitization compared to the others (87% v 67% v 15%; p<0.001). Adjusting for any history of endometriosis, those with myofascial trigger points were most likely sensitized (OR=9.41, 95% CI:1.77–50.08, p=0.009). Conclusions Sensitization and myofascial trigger points were common in women with pain regardless of whether they had endometriosis at surgery. Those with any history of endometriosis were most likely to have sensitization. Traditional methods of classifying endometriosis-associated pain based on disease, duration, and anatomy are inadequate and should be replaced by a mechanism-based evaluation, as our study illustrates. PMID:25730237

Functional interdependence at the chromatin level between the MKK6/p38 and IGF1/PI3K/AKT pathways during muscle differentiation.

PubMed

Serra, Carlo; Palacios, Daniela; Mozzetta, Chiara; Forcales, Sonia V; Morantte, Ianessa; Ripani, Meri; Jones, David R; Du, Keyong; Jhala, Ulupi S; Simone, Cristiano; Puri, Pier Lorenzo

2007-10-26

During muscle regeneration, the mechanism integrating environmental cues at the chromatin of muscle progenitors is unknown. We show that inflammation-activated MKK6-p38 and insulin growth factor 1 (IGF1)-induced PI3K/AKT pathways converge on the chromatin of muscle genes to target distinct components of the muscle transcriptosome. p38 alpha/beta kinases recruit the SWI/SNF chromatin-remodeling complex; AKT1 and 2 promote the association of MyoD with p300 and PCAF acetyltransferases, via direct phosphorylation of p300. Pharmacological or genetic interference with either pathway led to partial assembly of discrete chromatin-bound complexes, which reflected two reversible and distinct cellular phenotypes. Remarkably, PI3K/AKT blockade was permissive for chromatin recruitment of MEF2-SWI/SNF complex, whose remodeling activity was compromised in the absence of MyoD and acetyltransferases. The functional interdependence between p38 and IGF1/PI3K/AKT pathways was further established by the evidence that blockade of AKT chromatin targets was sufficient to prevent the activation of the myogenic program triggered by deliberate activation of p38 signaling.

Functional interdependence at the chromatin level between the MKK6/p38 and IGF1/Pi3K/AKT pathways during muscle differentiation

PubMed Central

Carlo, Serra; Daniela, Palacios; Chiara, Mozzetta; Sonia, Forcales; Ianessa, Morantte; Meri, Ripani; Jones David, R.; Keyong, Du; Jhala Ulupi, S.; Cristiano, Simone; Lorenzo, Puri Pier

2009-01-01

During muscle regeneration, the mechanism integrating environmental cues at the chromatin of muscle progenitors is unknown. We show that inflammation-activated MKK6-p38 and IGF1-induced Pi3K/AKT pathways converge on the chromatin of muscle genes to target distinct components of the muscle transcriptosome. p38 α/β kinases recruit the SWI/SNF chromatin-remodeling complex; AKT 1 and 2 promote the association of MyoD with p300 and PCAF acetyltransferases, via direct phosphorylation of p300. Pharmacological or genetic interference with either pathway led to partial assembly of discrete chromatin-bound complexes, which reflected two reversible and distinct cellular phenotypes. Remarkably, Pi3K/AKT blockade was permissive for chromatin recruitment of MEF2-SWI/SNF complex, whose remodeling activity was compromised in the absence of MyoD and acetyltransferases. The functional interdependence between p38 and IGF1/Pi3K/AKT pathways was further established by the evidence that blockade of AKT chromatin targets was sufficient to prevent the activation of the myogenic program triggered by deliberate activation of p38 signaling PMID:17964260

Quantitative assessment of fatty infiltration and muscle volume of the rotator cuff muscles using 3-dimensional 2-point Dixon magnetic resonance imaging.

PubMed

Matsumura, Noboru; Oguro, Sota; Okuda, Shigeo; Jinzaki, Masahiro; Matsumoto, Morio; Nakamura, Masaya; Nagura, Takeo

2017-10-01

In patients with rotator cuff tears, muscle degeneration is known to be a predictor of irreparable tears and poor outcomes after surgical repair. Fatty infiltration and volume of the whole muscles constituting the rotator cuff were quantitatively assessed using 3-dimensional 2-point Dixon magnetic resonance imaging. Ten shoulders with a partial-thickness tear, 10 shoulders with an isolated supraspinatus tear, and 10 shoulders with a massive tear involving supraspinatus and infraspinatus were compared with 10 control shoulders after matching age and sex. With segmentation of muscle boundaries, the fat fraction value and the volume of the whole rotator cuff muscles were computed. After reliabilities were determined, differences in fat fraction, muscle volume, and fat-free muscle volume were evaluated. Intra-rater and inter-rater reliabilities were regarded as excellent for fat fraction and muscle volume. Tendon rupture adversely increased the fat fraction value of the respective rotator cuff muscle (P < .002). In the massive tear group, muscle volume was significantly decreased in the infraspinatus (P = .035) and increased in the teres minor (P = .039). With subtraction of fat volume, a significant decrease of fat-free volume of the supraspinatus muscle became apparent with a massive tear (P = .003). Three-dimensional measurement could evaluate fatty infiltration and muscular volume with excellent reliabilities. The present study showed that chronic rupture of the tendon adversely increases the fat fraction of the respective muscle and indicates that the residual capacity of the rotator cuff muscles might be overestimated in patients with severe fatty infiltration. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Lower limb muscle strength is associated with poor balance in middle-aged women: linear and nonlinear analyses.

PubMed

Wu, F; Callisaya, M; Laslett, L L; Wills, K; Zhou, Y; Jones, G; Winzenberg, T

2016-07-01

This was the first study investigating both linear associations between lower limb muscle strength and balance in middle-aged women and the potential for thresholds for the associations. There was strong evidence that even in middle-aged women, poorer LMS was associated with reduced balance. However, no evidence was found for thresholds. Decline in balance begins in middle age, yet, the role of muscle strength in balance is rarely examined in this age group. We aimed to determine the association between lower limb muscle strength (LMS) and balance in middle-aged women and investigate whether cut-points of LMS exist that might identify women at risk of poorer balance. Cross-sectional analysis of 345 women aged 36-57 years was done. Associations between LMS and balance tests (timed up and go (TUG), step test (ST), functional reach test (FRT), and lateral reach test (LRT)) were assessed using linear regression. Nonlinear associations were explored using locally weighted regression smoothing (LOWESS) and potential cut-points identified using nonlinear least-squares estimation. Segmented regression was used to estimate associations above and below the identified cut-points. Weaker LMS was associated with poorer performance on the TUG (β -0.008 (95 % CI: -0.010, -0.005) second/kg), ST (β 0.031 (0.011, 0.051) step/kg), FRT (β 0.071 (0.047, 0.096) cm/kg), and LRT (β 0.028 (0.011, 0.044) cm/kg), independent of confounders. Potential nonlinear associations were evident from LOWESS results; significant cut-points of LMS were identified for all balance tests (29-50 kg). However, excepting ST, cut-points did not persist after excluding potentially influential data points. In middle-aged women, poorer LMS is associated with reduced balance. Therefore, improving muscle strength in middle-age may be a useful strategy to improve balance and reduce falls risk in later life. Middle-aged women with low muscle strength may be an effective target group for future randomized controlled trials. Australian New Zealand Clinical Trials Registry (ANZCTR) NCT00273260.

A Three Dimensional Model of the Feline Hindlimb

PubMed Central

Burkholder, Thomas J.; Richard Nichols, T.

2007-01-01

This paper describes a three dimensional musculoskeletal model of the feline hindlimb based on digitized musculoskeletal anatomy. The model consists of seven degrees of freedom: three at the hip and two each at the knee and ankle. Lines of action and via points for 32 major muscles of the limb are described. Interspecimen variability of muscle paths was surprisingly low: most via points displayed a scatter of only a few millimeters. Joint axes identified by mechanical techniques as non-coincident and non-orthogonal were further honed to yield moment arms consistent with previous reports. Interspecimen variability in joint axes was greater than that of muscle paths and highlights the importance of joint axes in kinematic models. The contribution of specific muscles to the direction of endpoint force generation is discussed. PMID:15164372

Cardiac myofilaments: mechanics and regulation

NASA Technical Reports Server (NTRS)

de Tombe, Pieter P.; Bers, D. M. (Principal Investigator)

2003-01-01

The mechanical properties of the cardiac myofilament are an important determinant of pump function of the heart. This report is focused on the regulation of myofilament function in cardiac muscle. Calcium ions form the trigger that induces activation of the thin filament which, in turn, allows for cross-bridge formation, ATP hydrolysis, and force development. The structure and protein-protein interactions of the cardiac sarcomere that are responsible for these processes will be reviewed. The molecular mechanism that underlies myofilament activation is incompletely understood. Recent experimental approaches have been employed to unravel the mechanism and regulation of myofilament mechanics and energetics by activator calcium and sarcomere length, as well as contractile protein phosphorylation mediated by protein kinase A. Central to these studies is the question whether such factors impact on muscle function simply by altering thin filament activation state, or whether modulation of cross-bridge cycling also plays a part in the responses of muscle to these stimuli.

Mechanotransduction in skeletal muscle

PubMed Central

Burkholder, Thomas J.

2007-01-01

Mechanical signals are critical to the development and maintenance of skeletal muscle, but the mechanisms that convert these shape changes to biochemical signals is not known. When a deformation is imposed on a muscle, changes in cellular and molecular conformations link the mechanical forces with biochemical signals, and the close integration of mechanical signals with electrical, metabolic, and hormonal signaling may disguise the aspect of the response that is specific to the mechanical forces. The mechanically induced conformational change may directly activate downstream signaling and may trigger messenger systems to activate signaling indirectly. Major effectors of mechanotransduction include the ubiquitous mitogen activated protein kinase (MAP) and phosphatidylinositol-3’ kinase (PI-3K), which have well described receptor dependent cascades, but the chain of events leading from mechanical stimulation to biochemical cascade is not clear. This review will discuss the mechanics of biological deformation, loading of cellular and molecular structures, and some of the principal signaling mechanisms associated with mechanotransduction. PMID:17127292

Mechanotransduction in skeletal muscle.

PubMed

Burkholder, Thomas J

2007-01-01

Mechanical signals are critical to the development and maintenance of skeletal muscle, but the mechanisms that convert these shape changes to biochemical signals is not known. When a deformation is imposed on a muscle, changes in cellular and molecular conformations link the mechanical forces with biochemical signals, and the close integration of mechanical signals with electrical, metabolic, and hormonal signaling may disguise the aspect of the response that is specific to the mechanical forces. The mechanically induced conformational change may directly activate downstream signaling and may trigger messenger systems to activate signaling indirectly. Major effectors of mechanotransduction include the ubiquitous mitogen activated protein kinase (MAP) and phosphatidylinositol-3' kinase (PI-3K), which have well described receptor dependent cascades, but the chain of events leading from mechanical stimulation to biochemical cascade is not clear. This review will discuss the mechanics of biological deformation, loading of cellular and molecular structures, and some of the principal signaling mechanisms associated with mechanotransduction.

The Role of Androgens and Estrogens on Healthy Aging and Longevity

PubMed Central

Dillon, E. Lichar; Urban, Randall J.; Sheffield-Moore, Melinda

2012-01-01

Aging is associated with a loss of sex hormone in both men (andropause) and women (menopause). In men, reductions in testosterone can trigger declines in muscle mass, bone mass, and in physical function. In women, the impact of the loss of sex hormones, such as estradiol, on bone is well elucidated, but evidence is limited on whether the loss of estradiol negatively affects muscle mass and physical function. However, deficiencies in multiple anabolic hormones have been shown to predict health status and longevity in older persons. Thus, consideration should be given as to whether targeted hormone replacement therapies may prove effective at treating clinical conditions, such as age-related sarcopenia, cancer cachexia, and/or acute or chronic illnesses. If initiated carefully in the appropriate clinical population, hormone replacement therapies in men and women may prevent and reverse muscle and bone loss and functional declines and perhaps promote healthy aging and longevity. PMID:22451474

Sporadic inclusion body myositis: the genetic contributions to the pathogenesis

PubMed Central

2014-01-01

Sporadic inclusion body myositis (sIBM) is the commonest idiopathic inflammatory muscle disease in people over 50 years old. It is characterized by slowly progressive muscle weakness and atrophy, with typical pathological changes of inflammation, degeneration and mitochondrial abnormality in affected muscle fibres. The cause(s) of sIBM are still unknown, but are considered complex, with the contribution of multiple factors such as environmental triggers, ageing and genetic susceptibility. This review summarizes the current understanding of the genetic contributions to sIBM and provides some insights for future research in this mysterious disease with the advantage of the rapid development of advanced genetic technology. An international sIBM genetic study is ongoing and whole-exome sequencing will be applied in a large cohort of sIBM patients with the aim of unravelling important genetic risk factors for sIBM. PMID:24948216

The myasthenic patient in crisis: an update of the management in Neurointensive Care Unit.

PubMed

Godoy, Daniel Agustin; Mello, Leonardo Jardim Vaz de; Masotti, Luca; Di Napoli, Mario

2013-09-01

Myasthenia gravis (MG) is an autoimmune disorder affecting neuromuscular transmission leading to generalized or localized muscle weakness due most frequently to the presence of autoantibodies against acetylcholine receptors in the postsynaptic motor end-plate. Myasthenic crisis (MC) is a complication of MG characterized by worsening muscle weakness, resulting in respiratory failure that requires intubation and mechanical ventilation. It also includes postsurgical patients, in whom exacerbation of muscle weakness from MG causes a delay in extubation. MC is a very important, serious, and reversible neurological emergency that affects 20-30% of the myasthenic patients, usually within the first year of illness and maybe the debut form of the disease. Most patients have a predisposing factor that triggers the crisis, generally an infection of the respiratory tract. Immunoglobulins, plasma exchange, and steroids are the cornerstones of immunotherapy. Today with the modern neurocritical care, mortality rate of MC is less than 5%.

Low level laser therapy on injured rat muscle: assessment of irradiation parameters

NASA Astrophysics Data System (ADS)

Mantineo, M.; Pinheiro, J. P.; Morgado, A. M.

2013-11-01

Although studies show the clinical effectiveness of low level laser therapy (LLLT) in facilitating the muscle healing process, scientific evidence is still required to prove the effectiveness of LLLT and to clarify the cellular and molecular mechanisms triggered by irradiation. Here we evaluate the effect of different LLLT wavelengths, using continuous coherent Laser illumination (830 nm and 980 nm) and non-coherent LED illumination (850 nm), in the treatment of inflammation induced in the gastrocnemius muscle of Wistar rats, through the quantification of cytokines in systemic blood. We verified that all applied doses of coherent radiation produce an effect on reducing the concentration of pro-inflammatory TNF-α and IL-1β cytokines, while no treatment effect was observed after irradiation with non-coherent radiation. The best results were obtained for 40 mW at 830 nm. The results may suggest an important role of coherence properties of laser in LLLT.

RYR1-related rhabdomyolysis: A common but probably underdiagnosed manifestation of skeletal muscle ryanodine receptor dysfunction.

PubMed

Voermans, N C; Snoeck, M; Jungbluth, H

2016-10-01

Mutations in the skeletal muscle ryanodine receptor (RYR1) gene are associated with a wide spectrum of inherited myopathies presenting throughout life. Malignant hyperthermia susceptibility (MHS)-related RYR1 mutations have emerged as a common cause of exertional rhabdomyolysis, accounting for up to 30% of rhabdomyolysis episodes in otherwise healthy individuals. Common triggers are exercise and heat and, less frequently, viral infections, alcohol and drugs. Most subjects are normally strong and have no personal or family history of malignant hyperthermia. Heat intolerance and cold-induced muscle stiffness may be a feature. Recognition of this (probably not uncommon) rhabdomyolysis cause is vital for effective counselling, to identify potentially malignant hyperthermia-susceptible individuals and to adapt training regimes. Studies in various animal models provide insights regarding possible pathophysiological mechanisms and offer therapeutic perspectives. Copyright © 2016. Published by Elsevier Masson SAS.

Control of abdominal muscles by brain stem respiratory neurons in the cat

NASA Technical Reports Server (NTRS)

Miller, Alan D.; Ezure, Kazuhisa; Suzuki, Ichiro

1985-01-01

The nature of the control of abdominal muscles by the brain stem respiratory neurons was investigated in decerebrate unanesthetized cats. First, it was determined which of the brain stem respiratory neurons project to the lumbar cord (from which the abdominal muscles receive part of their innervation), by stimulating the neurons monopolarly. In a second part of the study, it was determined if lumbar-projecting respiratory neurons make monosynaptic connections with abdominal motoneurons; in these experiments, discriminate spontaneous spikes of antidromically acivated expiratory (E) neurons were used to trigger activity from both L1 and L2 nerves. A large projection was observed from E neurons in the caudal ventral respiratory group to the contralateral upper lumber cord. However, cross-correlation experiments found only two (out of 47 neuron pairs tested) strong monosynaptic connections between brain stem neurons and abdominal motoneurons.

Geniohyoid muscle properties and myosin heavy chain composition are altered after short-term intermittent hypoxic exposure.

PubMed

Pae, Eung-Kwon; Wu, Jennifer; Nguyen, Daniel; Monti, Ryan; Harper, Ronald M

2005-03-01

Patients with obstructive sleep apnea (OSA) often exhibit fatigued or inefficient upper airway dilator and constrictor muscles; an upper airway dilator, the geniohyoid (GH) muscle, is a particular example. Intermittent hypoxia (IH) is a frequent concomitant of OSA, and it may trigger muscle fiber composition changes that are characteristic of a fatigable nature. We examined effects of short-term IH on diaphragmatic and GH muscle fiber composition and fatigue properties by exposing 24 rats to alternating 10.3% O(2)-balance N(2) and room air every 480 s (240 s duty cycle) for a total duration of 5, 10, 15, 20, or 30 h. Sternohyoid fiber composition was also examined. Control animals were exposed to room air on the same schedule. Single-fiber analyses showed that GH muscle fiber types changed completely from myosin heavy chain (MHC) type 2A to MHC type 2B after 10 h of exposure, and the conversion was maintained for at least 30 h. Sternohyoid muscle fibers showed a delayed transition from MHC type 2A/2B to MHC type 2B. In contrast, major fiber types of the diaphragm were not significantly altered. The GH muscles showed similar tension-frequency relationships in all groups, but an increased fatigability developed, proportional to the duration of IH treatment. We conclude that short-term IH exposure alters GH muscle composition and physical properties toward more fatigable, fast-twitch types and that it may account for the fatigable upper airway fiber types found in sleep-disturbed breathing.

Hyperammonemia in cirrhosis induces transcriptional regulation of myostatin by an NF-κB–mediated mechanism

PubMed Central

Qiu, Jia; Thapaliya, Samjhana; Runkana, Ashok; Yang, Yu; Tsien, Cynthia; Mohan, Maradumane L.; Narayanan, Arvind; Eghtesad, Bijan; Mozdziak, Paul E.; McDonald, Christine; Stark, George R.; Welle, Stephen; Naga Prasad, Sathyamangla V.; Dasarathy, Srinivasan

2013-01-01

Loss of muscle mass, or sarcopenia, is nearly universal in cirrhosis and adversely affects patient outcome. The underlying cross-talk between the liver and skeletal muscle mediating sarcopenia is not well understood. Hyperammonemia is a consistent abnormality in cirrhosis due to impaired hepatic detoxification to urea. We observed elevated levels of ammonia in both plasma samples and skeletal muscle biopsies from cirrhotic patients compared with healthy controls. Furthermore, skeletal muscle from cirrhotics had increased expression of myostatin, a known inhibitor of skeletal muscle accretion and growth. In vivo studies in mice showed that hyperammonemia reduced muscle mass and strength and increased myostatin expression in wild-type compared with postdevelopmental myostatin knockout mice. We postulated that hyperammonemia is an underlying link between hepatic dysfunction in cirrhosis and skeletal muscle loss. Therefore, murine C2C12 myotubes were treated with ammonium acetate resulting in intracellular concentrations similar to those in cirrhotic muscle. In this system, we demonstrate that hyperammonemia stimulated myostatin expression in a NF-κB–dependent manner. This finding was also observed in primary murine muscle cell cultures. Hyperammonemia triggered activation of IκB kinase, NF-κB nuclear translocation, binding of the NF-κB p65 subunit to specific sites within the myostatin promoter, and stimulation of myostatin gene transcription. Pharmacologic inhibition or gene silencing of NF-κB abolished myostatin up-regulation under conditions of hyperammonemia. Our work provides unique insights into hyperammonemia-induced myostatin expression and suggests a mechanism by which sarcopenia develops in cirrhotic patients. PMID:24145431

Chronic losartan administration reduces mortality and preserves cardiac but not skeletal muscle function in dystrophic mice.

PubMed

Bish, Lawrence T; Yarchoan, Mark; Sleeper, Meg M; Gazzara, Jeffrey A; Morine, Kevin J; Acosta, Pedro; Barton, Elisabeth R; Sweeney, H Lee

2011-01-01

Duchenne muscular dystrophy (DMD) is a degenerative disorder affecting skeletal and cardiac muscle for which there is no effective therapy. Angiotension receptor blockade (ARB) has excellent therapeutic potential in DMD based on recent data demonstrating attenuation of skeletal muscle disease progression during 6-9 months of therapy in the mdx mouse model of DMD. Since cardiac-related death is major cause of mortality in DMD, it is important to evaluate the effect of any novel treatment on the heart. Therefore, we evaluated the long-term impact of ARB on both the skeletal muscle and cardiac phenotype of the mdx mouse. Mdx mice received either losartan (0.6 g/L) (n = 8) or standard drinking water (n = 9) for two years, after which echocardiography was performed to assess cardiac function. Skeletal muscle weight, morphology, and function were assessed. Fibrosis was evaluated in the diaphragm and heart by Trichrome stain and by determination of tissue hydroxyproline content. By the study endpoint, 88% of treated mice were alive compared to only 44% of untreated (p = 0.05). No difference in skeletal muscle morphology, function, or fibrosis was noted in losartan-treated animals. Cardiac function was significantly preserved with losartan treatment, with a trend towards reduction in cardiac fibrosis. We saw no impact on the skeletal muscle disease progression, suggesting that other pathways that trigger fibrosis dominate over angiotensin II in skeletal muscle long term, unlike the situation in the heart. Our study suggests that ARB may be an important prophylactic treatment for DMD-associated cardiomyopathy, but will not impact skeletal muscle disease.

Hyperammonemia in cirrhosis induces transcriptional regulation of myostatin by an NF-κB-mediated mechanism.

PubMed

Qiu, Jia; Thapaliya, Samjhana; Runkana, Ashok; Yang, Yu; Tsien, Cynthia; Mohan, Maradumane L; Narayanan, Arvind; Eghtesad, Bijan; Mozdziak, Paul E; McDonald, Christine; Stark, George R; Welle, Stephen; Naga Prasad, Sathyamangla V; Dasarathy, Srinivasan

2013-11-05

Loss of muscle mass, or sarcopenia, is nearly universal in cirrhosis and adversely affects patient outcome. The underlying cross-talk between the liver and skeletal muscle mediating sarcopenia is not well understood. Hyperammonemia is a consistent abnormality in cirrhosis due to impaired hepatic detoxification to urea. We observed elevated levels of ammonia in both plasma samples and skeletal muscle biopsies from cirrhotic patients compared with healthy controls. Furthermore, skeletal muscle from cirrhotics had increased expression of myostatin, a known inhibitor of skeletal muscle accretion and growth. In vivo studies in mice showed that hyperammonemia reduced muscle mass and strength and increased myostatin expression in wild-type compared with postdevelopmental myostatin knockout mice. We postulated that hyperammonemia is an underlying link between hepatic dysfunction in cirrhosis and skeletal muscle loss. Therefore, murine C2C12 myotubes were treated with ammonium acetate resulting in intracellular concentrations similar to those in cirrhotic muscle. In this system, we demonstrate that hyperammonemia stimulated myostatin expression in a NF-κB-dependent manner. This finding was also observed in primary murine muscle cell cultures. Hyperammonemia triggered activation of IκB kinase, NF-κB nuclear translocation, binding of the NF-κB p65 subunit to specific sites within the myostatin promoter, and stimulation of myostatin gene transcription. Pharmacologic inhibition or gene silencing of NF-κB abolished myostatin up-regulation under conditions of hyperammonemia. Our work provides unique insights into hyperammonemia-induced myostatin expression and suggests a mechanism by which sarcopenia develops in cirrhotic patients.

Comparative morphology of the muscles of mastication in the giant panda and the Asiatic black bear.

PubMed

Endo, Hideki; Taru, Hajime; Yamamoto, Masako; Arishima, Kazuyoshi; Sasaki, Motoki

2003-06-01

The morphological differences in the muscles of mastication between the giant panda (Ailuropoda melanoleuca) and the Asiatic black bear (Ursus thibetanus) were sought to confirm the adaptational strategy of these muscles in the giant panda. We measured some skull characteristics and weighed the muscles of mastication, and macroscopically observed the muscles of mastication in the two species. The noticeable differences between the two species are classified as follows: (1) The size ratio of the zygomatic width was much larger in the giant panda than in the Asiatic black bear. (2) The weight ratio of the two pterygoid muscles was also much larger in the giant panda than in the Asiatic black bear. (3) The lateral slips of the temporal muscles are thicker and stronger in the Asiatic black bear than in the giant panda. (4) The deep layer of the masseter muscle was rostrocaudally divided, and a complicated running of tendons is observed in the giant panda. (5) The two pterygoid muscles were much larger and well-developed in the giant panda than in the Asiatic black bear. The points (1) and (4) may be related to the generation of the force necessary to chew the bamboo in the giant panda. We thought that the large mass of the masseter and temporal muscles are needed in this species. In the points of (2) and (5), the two pterygoid muscles were obviously different in form and weight ratio between the two species. We suggest that the two pterygoid muscles may act as an additional force generator to dorsoventrally press and crush bamboo stems.

Neurorehabilitation with new functional electrical stimulation for hemiparetic upper extremity in stroke patients.

PubMed

Hara, Yukihiro

2008-02-01

In recent years, our understanding of motor learning, neuroplasticity, and functional recovery after the occurrence of brain lesion has grown significantly. New findings in basic neuroscience have stimulated research in motor rehabilitation. Repeated motor practice and motor activity in a real-world environment have been identified in several prospective studies as favorable for motor recovery in stroke patients. Electrical stimulation can be applied in a variety of ways to the hemiparetic upper extremity following stroke. In this paper, an overview of current research into clinical and therapeutic applications of functional electrical stimulation (FES) is presented. In particular, electromyography (EMG)-initiated electrical muscle stimulation--but not electrical muscle stimulation alone--improves the motor function of the hemiparetic arm and hand. Triggered electrical stimulation is reported to be more effective than untriggered electrical stimulation in facilitating upper extremity motor recovery following stroke. Power-assisted FES induces greater muscle contraction by electrical stimulation in proportion to the voluntary integrated EMG signal picked up, which is regulated by a closed-loop control system. Power-assisted FES and motor point block for antagonist muscles have been applied with good results as a new hybrid FES therapy in an outpatient rehabilitation clinic for patients with stroke. Furthermore, a daily home program therapy with power-assisted FES using new equipment has been able to effectively improve wrist and finger extension and shoulder flexion. Proprioceptive sensory feedback might play an important role in power-assisted FES therapy. Although many physiotherapeutic modalities have been established, conclusive proof of their benefit and physiological models of their effects on neuronal structures and processes are still missing. A multichannel near-infrared spectroscopy study to noninvasively and dynamically measure hemoglobin levels in the brain during functional activity has shown that cerebral blood flow in the sensory-motor cortex on the injured side is higher during a power-assisted FES session than during simple active movement or simple electrical stimulation. Nevertheless, evidence-based strategies for motor rehabilitation are more easily available, particularly for patients with hemiparesis.

Ex Vivo Machine Perfusion in CTA with a Novel Oxygen Carrier System to Enhance Graft Preservation and Immunologic Outcomes

DTIC Science & Technology

2014-10-01

rectus abdominal muscle, autotransplantation, heterotopic, superior epigastric vein, cold ischemia time, immunomodulation, transcriptomics...composite flap (muscle, adipose tissue and skin) from the whole rectus abdominal muscle (RAM). This model was maximized through extensive anatomical...The biopsies included Skin - Subcutaneous Fat – Muscle. (9 tissue samples per each biopsy time point for each flap) The biopsies were taken by punches

Identification of Differentially Expressed Genes in Breast Muscle and Skin Fat of Postnatal Pekin Duck

PubMed Central

Schachtschneider, Kyle Michael; Liu, Xiaolin; Huang, Wei; Xie, Ming; Hou, Shuisheng

2014-01-01

Lean-type Pekin duck is a commercial breed that has been obtained through long-term selection. Investigation of the differentially expressed genes in breast muscle and skin fat at different developmental stages will contribute to a comprehensive understanding of the potential mechanisms underlying the lean-type Pekin duck phenotype. In the present study, RNA-seq was performed on breast muscle and skin fat at 2-, 4- and 6-weeks of age. More than 89% of the annotated duck genes were covered by our RNA-seq dataset. Thousands of differentially expressed genes, including many important genes involved in the regulation of muscle development and fat deposition, were detected through comparison of the expression levels in the muscle and skin fat of the same time point, or the same tissue at different time points. KEGG pathway analysis showed that the differentially expressed genes clustered significantly in many muscle development and fat deposition related pathways such as MAPK signaling pathway, PPAR signaling pathway, Calcium signaling pathway, Fat digestion and absorption, and TGF-beta signaling pathway. The results presented here could provide a basis for further investigation of the mechanisms involved in muscle development and fat deposition in Pekin duck. PMID:25264787

Non-linear scaling of a musculoskeletal model of the lower limb using statistical shape models.

PubMed

Nolte, Daniel; Tsang, Chui Kit; Zhang, Kai Yu; Ding, Ziyun; Kedgley, Angela E; Bull, Anthony M J

2016-10-03

Accurate muscle geometry for musculoskeletal models is important to enable accurate subject-specific simulations. Commonly, linear scaling is used to obtain individualised muscle geometry. More advanced methods include non-linear scaling using segmented bone surfaces and manual or semi-automatic digitisation of muscle paths from medical images. In this study, a new scaling method combining non-linear scaling with reconstructions of bone surfaces using statistical shape modelling is presented. Statistical Shape Models (SSMs) of femur and tibia/fibula were used to reconstruct bone surfaces of nine subjects. Reference models were created by morphing manually digitised muscle paths to mean shapes of the SSMs using non-linear transformations and inter-subject variability was calculated. Subject-specific models of muscle attachment and via points were created from three reference models. The accuracy was evaluated by calculating the differences between the scaled and manually digitised models. The points defining the muscle paths showed large inter-subject variability at the thigh and shank - up to 26mm; this was found to limit the accuracy of all studied scaling methods. Errors for the subject-specific muscle point reconstructions of the thigh could be decreased by 9% to 20% by using the non-linear scaling compared to a typical linear scaling method. We conclude that the proposed non-linear scaling method is more accurate than linear scaling methods. Thus, when combined with the ability to reconstruct bone surfaces from incomplete or scattered geometry data using statistical shape models our proposed method is an alternative to linear scaling methods. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

EEG controlled neuromuscular electrical stimulation of the upper limb for stroke patients

NASA Astrophysics Data System (ADS)

Tan, Hock Guan; Shee, Cheng Yap; Kong, Keng He; Guan, Cuntai; Ang, Wei Tech

2011-03-01

This paper describes the Brain Computer Interface (BCI) system and the experiments to allow post-acute (<3 months) stroke patients to use electroencephalogram (EEG) to trigger neuromuscular electrical stimulation (NMES)-assisted extension of the wrist/fingers, which are essential pre-requisites for useful hand function. EEG was recorded while subjects performed motor imagery of their paretic limb, and then analyzed to determine the optimal frequency range within the mu-rhythm, with the greatest attenuation. Aided by visual feedback, subjects then trained to regulate their mu-rhythm EEG to operate the BCI to trigger NMES of the wrist/finger. 6 post-acute stroke patients successfully completed the training, with 4 able to learn to control and use the BCI to initiate NMES. This result is consistent with the reported BCI literacy rate of healthy subjects. Thereafter, without the loss of generality, the controller of the NMES is developed and is based on a model of the upper limb muscle (biceps/triceps) groups to determine the intensity of NMES required to flex or extend the forearm by a specific angle. The muscle model is based on a phenomenological approach, with parameters that are easily measured and conveniently implemented.

Physical activity and sarcopenic obesity: definition, assessment, prevalence and mechanism.

PubMed

Lee, Duck-Chul; Shook, Robin P; Drenowatz, Clemens; Blair, Steven N

2016-09-01

Sarcopenic obesity is the coexistance of sarcopenia and obesity. Modern sarcopenia definition includes low muscle mass, weak muscle strength (handgrip strength) and poor physical function (slow walking), although the clinical definition of each varies worldwide. The cut-points for low muscle mass for men and women using appendicular lean mass divided by height (kg/m 2 ) are ≤7.0 and ≤5.4 in Asians, and ≤7.23 and ≤5.67 in Caucasians, respectively. The cut-points for weak handgrip strength (kg) for men and women are <26 and <18 in Asians, and <30 and <20 in Caucasians, respectively. The cut-point for slow walking is ≤0.8 m/s in men and women. Current data suggest the potential benefits of physical activity and fitness on sarcopenic obesity in older adults.

Ergonomic comparison of operating a built-in touch-pad pointing device and a trackball mouse on posture and muscle activity.

PubMed

Lee, Tzu-Hsien

2005-12-01

This study examined the effects of operating a built-in touch-pad pointing device and a trackball mouse on participants' completion times, hand positions during operation, postural angles, and muscle activities. 8 young men were asked to perform a cursor travel task on a notebook computer using both 60- and 80-cm high table conditions. Analysis showed that the trackball mouse significantly decreased completion times. Participants selected a hand position farther from the table edge and larger elbow angle for the trackball mouse than for the built-in touch-pad pointing device. Participants' neck, thoracic, and arm angles, or splenius capitis, trapezius, deltoid, and erector spinae muscle activities were not significantly affected by the devices, but table height significantly affected participants' completion times, hand positions, and postural angles.

Development of anticipatory postural adjustments during locomotion in children.

PubMed

Hirschfeld, H; Forssberg, H

1992-08-01

1. Anticipatory postural adjustments were studied in children (6-14 yr of age) walking on a treadmill while pulling a handle. Electromyographs (EMGs) and movements were recorded from the left arm and leg. 2. Postural activity in the leg muscles preceded voluntary arm muscle activity in all age groups, including the youngest children (6 yr of age). The latency to both leg and arm muscle activity, from a triggering audio signal, decreased with age. 3. In older children the latency to both voluntary and postural activity was influenced by the phase of the step cycle. The shortest latency to the first activated postural muscle occurred during single support phase in combination with a long latency to arm muscle activity. 4. In the youngest children, there was no phase-dependent modulation of the latency to the activation of the postural muscles. The voluntary activity was delayed during the beginning of the support phase resulting in a long delay between leg and arm muscle activity. 5. The postural muscle activation pattern was modified in a phase-dependent manner in all children. Lateral gastrocnemius (LG) and hamstring muscles (HAM) were activated during the early support phase, whereas tibialis anterior (TA) and quadriceps (Q) muscles were activated during the late support phase and during the swing phase. However, in the 6-yr-old children, LG was also activated in the swing phase. LG was activated before the HAM activity in the youngest children but after HAM in 14-yr-old children and adults. 6. The occurrence of LG activity in postural responses before heel strike suggests an immature (nonplantigrade) gating of postural activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Vitamin D-binding protein deficiency in mice decreases systemic and select tissue levels of inflammatory cytokines in a murine model of acute muscle injury.

PubMed

Kew, Richard R; Tabrizian, Tahmineh; Vosswinkel, James A; Davis, James E; Jawa, Randeep S

2018-06-01

Severe acute muscle injury results in massive cell damage, causing the release of actin into extracellular fluids where it complexes with the vitamin D-binding protein (DBP). We hypothesized that a systemic DBP deficiency would result in a less proinflammatory phenotype. C57BL/6 wild-type (WT) and DBP-deficient (DBP-/-) mice received intramuscular injections of either 50% glycerol or phosphate-buffered saline into thigh muscles. Muscle injury was assessed by histology. Cytokine levels were measured in plasma, muscle, kidney, and lung. All animals survived the procedure, but glycerol injection in both strains of mice showed lysis of skeletal myocytes and inflammatory cell infiltrate. The muscle inflammatory cell infiltrate in DBP-deficient mice had remarkably few neutrophils as compared with WT mice. The neutrophil chemoattractant CXCL1 was significantly reduced in muscle tissue from DBP-/- mice. However, there were no other significant differences in muscle cytokine levels. In contrast, plasma obtained 48 hours after glycerol injection revealed that DBP-deficient mice had significantly lower levels of systemic cytokines interleukin 6, CCL2, CXCL1, and granulocyte colony-stimulating factor. Lung tissue from DBP-/- mice showed significantly decreased amounts of CCL2 and CXCL1 as compared with glycerol-treated WT mice. Several chemokines in kidney homogenates following glycerol-induced injury were significantly reduced in DBP-/- mice: CCL2, CCL5, CXCL1, and CXCL2. Acute muscle injury triggered a systemic proinflammatory response as noted by elevated plasma cytokine levels. However, mice with a systemic DBP deficiency demonstrated a change in their cytokine profile 48 hours after muscle injury to a less proinflammatory phenotype.

A rat model of spontaneous myopathy and malignant hyperthermia.

PubMed Central

Gonzalez, L. E.; Meléndez-Vásquez, C. V.; Gregson, N. A.; File, S. E.

1998-01-01

Malignant hyperthermia is a main cause of death during general anesthesia, particularly in children. However, research has been hampered by the lack of a convenient animal model, the only one available being a special strain of pig. In this study, we describe spontaneous myopathy and a fatal syndrome of generalized muscle rigidity triggered by halothane in an outbred strain of rat. Histological examination of skeletal muscle reveals severe abnormalities indicating chronic underlying myopathy. The association of histological abnormalities with an acute, fatal syndrome clinically resembling malignant hyperthermia provides a strong basis for a new and extremely useful animal model to study this fatal disorder. Images Figure 1 Figure 2 PMID:9546371

A multi-responsive water-driven actuator with instant and powerful performance for versatile applications

NASA Astrophysics Data System (ADS)

Mu, Jiuke; Hou, Chengyi; Zhu, Bingjie; Wang, Hongzhi; Li, Yaogang; Zhang, Qinghong

2015-03-01

Mechanical actuators driven by water that respond to multiple stimuli, exhibit fast responses and large deformations, and generate high stress have potential in artificial muscles, motors, and generators. Meeting all these requirements in a single device remains a challenge. We report a graphene monolayer paper that undergoes reversible deformation. Its graphene oxide cells wrinkle and extend in response to water desorption and absorption, respectively. Its fast (~0.3 s), powerful (>100 MPa output stress, 7.5 × 105 N kg-1 unit mass force), and controllable actuation can be triggered by moisture, heat, and light. The graphene monolayer paper has potential in artificial muscles, robotic hands, and electromagnetic-free generators.

Immune-mediated statin myopathy.

PubMed

Loganathan, Priyadarshini; Oddis, Chester V; Aggarwal, Rohit

2016-01-01

Statin-induced necrotizing autoimmune myopathy (SINAM) is associated with a unique clinical 5 phenotype of severe proximal muscle weakness during or after exposure to statins in patients with high creatine kinase (CK) levels. Electromyography (EMG) and muscle biopsy reveal features of a necrotizing myopathy and the anti-HMGCR autoantibody is frequently detected. Treatment requires a combination of statin discontinuation as well as immunomodulatory or immunosuppressive therapy. HLA typing (HLADRB1*1101) is strongly associated with anti-10 HMGCR autoantibody positivity in statin-exposed patients. It is well documented that statin triggers autoimmune disease in those with a genetic susceptibility. With the commercial availability of an accurate ELISA test, the natural history of the disease and its phenotypic features are becoming increasingly understood.

Neurophysiological and clinical effects of dry needling in patients with upper trapezius myofascial trigger points.

PubMed

Abbaszadeh-Amirdehi, Maryam; Ansari, Noureddin Nakhostin; Naghdi, Soofia; Olyaei, Gholamreza; Nourbakhsh, Mohammad Reza

2017-01-01

Dry needling (DN) is a widely used in treatment of myofascial trigger points (MTrPs). The purpose of this pretest-posttest clinical trial was to investigate the neurophysiological and clinical effects of DN in patients with MTrPs. A sample of 20 patients (3 man, 17 women; mean age 31.7 ± 10.8) with upper trapezius MTrPs received one session of deep DN. The outcomes of neuromuscular junction response (NMJR), sympathetic skin response (SSR), pain intensity (PI) and pressure pain threshold (PPT) were measured at baseline and immediately after DN. There were significant improvements in SSR latency and amplitude, pain, and PPT after DN. The NMJR decreased and returned to normal after DN. A single session of DN to the active upper trapezius MTrP was effective in improving pain, PPT, NMJR, and SSR in patients with myofascial trigger points. Further studies are needed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Costamere remodeling with muscle loading and unloading in healthy young men.

PubMed

Li, Ruowei; Narici, Marco V; Erskine, Robert M; Seynnes, Olivier R; Rittweger, Jörn; Pišot, Rado; Šimunič, Boštjan; Flück, Martin

2013-11-01

Costameres are mechano-sensory sites of focal adhesion in the sarcolemma that provide a structural anchor for myofibrils. Their turnover is regulated by integrin-associated focal adhesion kinase (FAK). We hypothesized that changes in content of costamere components (beta 1 integrin, FAK, meta-vinculin, gamma-vinculin) with increased and reduced loading of human anti-gravity muscle would: (i) relate to changes in muscle size and molecular parameters of muscle size regulation [p70S6K, myosin heavy chain (MHC)1 and MHCIIA]; (ii) correspond to adjustments in activity and expression of FAK, and its negative regulator, FRNK; and (iii) reflect the temporal response to reduced and increased loading. Unloading induced a progressive decline in thickness of human vastus lateralis muscle after 8 and 34 days of bedrest (-4% and -14%, respectively; n = 9), contrasting the increase in muscle thickness after 10 and 27 days of resistance training (+5% and +13%; n = 6). Changes in muscle thickness were correlated with changes in cross-sectional area of type I muscle fibers (r = 0.66) and beta 1 integrin content (r = 0.76) at the mid-point of altered loading. Changes in meta-vinculin and FAK-pY397 content were correlated (r = 0.85) and differed, together with the changes of beta 1 integrin, MHCI, MHCII and p70S6K, between the mid- and end-point of resistance training. By contrast, costamere protein level changes did not differ between time points of bedrest. The findings emphasize the role of FAK-regulated costamere turnover in the load-dependent addition and removal of myofibrils, and argue for two phases of muscle remodeling with resistance training, which do not manifest at the macroscopic level. © 2013 The Authors. Journal of Anatomy published by John Wiley & Sons Ltd on behalf of Anatomical Society.

Voluntary Control of Residual Antagonistic Muscles in Transtibial Amputees: Feedforward Ballistic Contractions and Implications for Direct Neural Control of Powered Lower Limb Prostheses.

PubMed

Huang, Stephanie; Huang, He

2018-04-01

Discrete, rapid (i.e., ballistic like) muscle activation patterns have been observed in ankle muscles (i.e., plantar flexors and dorsiflexors) of able-bodied individuals during voluntary posture control. This observation motivated us to investigate whether transtibial amputees are capable of generating such a ballistic-like activation pattern accurately using their residual ankle muscles in order to assess whether the volitional postural control of a powered ankle prosthesis using proportional myoelectric control via residual muscles could be feasible. In this paper, we asked ten transtibial amputees to generate ballistic-like activation patterns using their residual lateral gastrocnemius and residual tibialis anterior to control a computer cursor via proportional myoelectric control to hit targets positioned at 20% and 40% of maximum voluntary contraction of the corresponding residual muscle. During practice conditions, we asked amputees to hit a single target repeatedly. During testing conditions, we asked amputees to hit a random sequence of targets. We compared movement time to target and end-point accuracy. We also examined motor recruitment synchronization via time-frequency representations of residual muscle activation. The result showed that median end-point error ranged from -0.6% to 1% maximum voluntary contraction across subjects during practice, which was significantly lower compared to testing ( ). Average movement time for all amputees was 242 ms during practice and 272 ms during testing. Motor recruitment synchronization varied across subjects, and amputees with the highest synchronization achieved the fastest movement times. End-point accuracy was independent of movement time. Results suggest that it is feasible for transtibial amputees to generate ballistic control signals using their residual muscles. Future work on volitional control of powered power ankle prostheses might consider anticipatory postural control based on ballistic-like residual muscle activation patterns and direct continuous proportional myoelectric control.

An analysis of the relationships between subthreshold electrical properties and excitability in skeletal muscle

PubMed Central

L.-H. Huang, Christopher; Fraser, James A.

2011-01-01

Skeletal muscle activation requires action potential (AP) initiation followed by its sarcolemmal propagation and tubular excitation to trigger Ca2+ release and contraction. Recent studies demonstrate that ion channels underlying the resting membrane conductance (GM) of fast-twitch mammalian muscle fibers are highly regulated during muscle activity. Thus, onset of activity reduces GM, whereas prolonged activity can markedly elevate GM. Although these observations implicate GM regulation in control of muscle excitability, classical theoretical studies in un-myelinated axons predict little influence of GM on membrane excitability. However, surface membrane morphologies differ markedly between un-myelinated axons and muscle fibers, predominantly because of the tubular (t)-system of muscle fibers. This study develops a linear circuit model of mammalian muscle fiber and uses this to assess the role of subthreshold electrical properties, including GM changes during muscle activity, for AP initiation, AP propagation, and t-system excitation. Experimental observations of frequency-dependent length constant and membrane-phase properties in fast-twitch rat fibers could only be replicated by models that included t-system luminal resistances. Having quantified these resistances, the resulting models showed enhanced conduction velocity of passive current flow also implicating elevated AP propagation velocity. Furthermore, the resistances filter passive currents such that higher frequency current components would determine sarcolemma AP conduction velocity, whereas lower frequency components excite t-system APs. Because GM modulation affects only the low-frequency membrane impedance, the GM changes in active muscle would predominantly affect neuromuscular transmission and low-frequency t-system excitation while exerting little influence on the high-frequency process of sarcolemmal AP propagation. This physiological role of GM regulation was increased by high Cl− permeability, as in muscle endplate regions, and by increased extracellular [K+], as observed in working muscle. Thus, reduced GM at the onset of exercise would enhance t-system excitation and neuromuscular transmission, whereas elevated GM after sustained activity would inhibit these processes and thereby accentuate muscle fatigue. PMID:21670208

The TORC1/P70S6K and TORC1/4EBP1 signaling pathways have a stronger contribution on skeletal muscle growth than MAPK/ERK in an early vertebrate: Differential involvement of the IGF system and atrogenes.

PubMed

Fuentes, Eduardo N; Einarsdottir, Ingibjörg Eir; Paredes, Rodolfo; Hidalgo, Christian; Valdes, Juan Antonio; Björnsson, Björn Thrandur; Molina, Alfredo

2015-01-01

Knowledge about the underlying mechanisms, particularly the signaling pathways that account for muscle growth in vivo in early vertebrates is still scarce. Fish (Paralichthys adspersus) were fasted for 3weeks to induce a catabolic period of strong muscle atrophy. Subsequently, fish were refed for 2weeks to induce compensatory muscle hypertrophy. During refeeding, the fish were treated daily with either rapamycin (TORC blocker), PD98059 (MEK blocker), or PBS (V; vehicle), or were untreated (C; control). Rapamycin and PD98059 differentially impaired muscle cellularity in vivo, growth performance, and the expression of growth-related genes, and the inhibition of TORC1 had a greater impact on fish muscle growth than the inhibition of MAPK. Blocking TORC1 inhibited the phosphorylation of P70S6K and 4EBP1, two downstream components activated by TORC1, thus affecting protein contents in muscle. Concomitantly, the gene expression in muscle of igf-1, 2 and igfbp-4, 5 was down-regulated while the expression of atrogin-1, murf-1, and igfbp-2, 3 was up-regulated. Muscle hypertrophy was abolished and muscle atrophy was promoted, which finally affected body weight. TORC2 complex was not affected by rapamycin. On the other hand, the PD98059 treatment triggered ERK inactivation, a downstream component activated by MEK. mRNA contents of igf-1 in muscle were down-regulated, and muscle hypertrophy was partially impaired. The present study provides the first direct data on the in vivo contribution of TORC1/P70S6K, TORC1/4EBP1, and MAPK/ERK signaling pathways in the skeletal muscle of an earlier vertebrate, and highlights the transcendental role of TORC1 in growth from the cellular to organism level. Copyright © 2014 Elsevier Inc. All rights reserved.

DNA methyltransferase inhibitor CDA-II inhibits myogenic differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Zirong; Department of Molecular Genetics and Microbiology, Shands Cancer Center, University of Florida, Gainesville, FL 32610; Jin, Guorong

2012-06-08

Highlights: Black-Right-Pointing-Pointer CDA-II inhibits myogenic differentiation in a dose-dependent manner. Black-Right-Pointing-Pointer CDA-II repressed expression of muscle transcription factors and structural proteins. Black-Right-Pointing-Pointer CDA-II inhibited proliferation and migration of C2C12 myoblasts. -- Abstract: CDA-II (cell differentiation agent II), isolated from healthy human urine, is a DNA methyltransferase inhibitor. Previous studies indicated that CDA-II played important roles in the regulation of cell growth and certain differentiation processes. However, it has not been determined whether CDA-II affects skeletal myogenesis. In this study, we investigated effects of CDA-II treatment on skeletal muscle progenitor cell differentiation, migration and proliferation. We found that CDA-II blocked differentiationmore » of murine myoblasts C2C12 in a dose-dependent manner. CDA-II repressed expression of muscle transcription factors, such as Myogenin and Mef2c, and structural proteins, such as myosin heavy chain (Myh3), light chain (Mylpf) and MCK. Moreover, CDA-II inhibited C1C12 cell migration and proliferation. Thus, our data provide the first evidence that CDA-II inhibits growth and differentiation of muscle progenitor cells, suggesting that the use of CDA-II might affect skeletal muscle functions.« less

How to Quantify Penile Corpus Cavernosum Structures with Histomorphometry: Comparison of Two Methods

PubMed Central

Felix-Patrício, Bruno; De Souza, Diogo Benchimol; Gregório, Bianca Martins; Costa, Waldemar Silva; Sampaio, Francisco José

2015-01-01

The use of morphometrical tools in biomedical research permits the accurate comparison of specimens subjected to different conditions, and the surface density of structures is commonly used for this purpose. The traditional point-counting method is reliable but time-consuming, with computer-aided methods being proposed as an alternative. The aim of this study was to compare the surface density data of penile corpus cavernosum trabecular smooth muscle in different groups of rats, measured by two observers using the point-counting or color-based segmentation method. Ten normotensive and 10 hypertensive male rats were used in this study. Rat penises were processed to obtain smooth muscle immunostained histological slices and photomicrographs captured for analysis. The smooth muscle surface density was measured in both groups by two different observers by the point-counting method and by the color-based segmentation method. Hypertensive rats showed an increase in smooth muscle surface density by the two methods, and no difference was found between the results of the two observers. However, surface density values were higher by the point-counting method. The use of either method did not influence the final interpretation of the results, and both proved to have adequate reproducibility. However, as differences were found between the two methods, results obtained by either method should not be compared. PMID:26413547

How to Quantify Penile Corpus Cavernosum Structures with Histomorphometry: Comparison of Two Methods.

PubMed

Felix-Patrício, Bruno; De Souza, Diogo Benchimol; Gregório, Bianca Martins; Costa, Waldemar Silva; Sampaio, Francisco José

2015-01-01

The use of morphometrical tools in biomedical research permits the accurate comparison of specimens subjected to different conditions, and the surface density of structures is commonly used for this purpose. The traditional point-counting method is reliable but time-consuming, with computer-aided methods being proposed as an alternative. The aim of this study was to compare the surface density data of penile corpus cavernosum trabecular smooth muscle in different groups of rats, measured by two observers using the point-counting or color-based segmentation method. Ten normotensive and 10 hypertensive male rats were used in this study. Rat penises were processed to obtain smooth muscle immunostained histological slices and photomicrographs captured for analysis. The smooth muscle surface density was measured in both groups by two different observers by the point-counting method and by the color-based segmentation method. Hypertensive rats showed an increase in smooth muscle surface density by the two methods, and no difference was found between the results of the two observers. However, surface density values were higher by the point-counting method. The use of either method did not influence the final interpretation of the results, and both proved to have adequate reproducibility. However, as differences were found between the two methods, results obtained by either method should not be compared.

Differences in end-point force trajectories elicited by electrical stimulation of individual human calf muscles

PubMed Central

Giordano, S B; Segal, R L; Abelew, T A

2009-01-01

The purpose of this study was to investigate the end-point force trajectories of the fibularis longus (FIB), lateral gastrocnemius (LG) and medial gastrocnemius (MG) muscles. Most information about individual muscle function has come from studies which use models based on electromyographic (EMG) recordings. In this study (N=20 subjects) we used electrical stimulation (20Hz) to elicit activity in individual muscles, recorded the end-point forces at the foot and verified the selectivity of stimulation by using magnetic resonance imaging. Unexpectedly, no significant differences were found between LG and MG force directions. Stimulation of LG and MG resulted in downward and medial or lateral forces depending on the subject. We found FIB end-point forces to be significantly different than those of LG and MG. In all subjects, stimulation of FIB resulted in downward and lateral forces. Based on our results, we suggest that there are multiple factors determining when and whether LG or MG will produce a medial or lateral force and FIB consistently plays a significant role in eversion/abduction and plantarflexion. We suggest that the inter-subject variability we found is not simply an artifact of experimental or technical error but is functionally relevant and should be addressed in future studies and models. PMID:20095454

Channelopathies of skeletal muscle excitability

PubMed Central

Cannon, Stephen C.

2016-01-01

Familial disorders of skeletal muscle excitability were initially described early in the last century and are now known to be caused by mutations of voltage-gated ion channels. The clinical manifestations are often striking, with an inability to relax after voluntary contraction (myotonia) or transient attacks of severe weakness (periodic paralysis). An essential feature of these disorders is fluctuation of symptoms that are strongly impacted by environmental triggers such as exercise, temperature, or serum K+ levels. These phenomena have intrigued physiologists for decades, and in the past 25 years the molecular lesions underlying these disorders have been identified and mechanistic studies are providing insights for therapeutic strategies of disease modification. These familial disorders of muscle fiber excitability are “channelopathies” caused by mutations of a chloride channel (ClC-1), sodium channel (NaV1.4), calcium channel (CaV1.1) and several potassium channels (Kir2.1, Kir2.6, Kir3.4). This review provides a synthesis of the mechanistic connections between functional defects of mutant ion channels, their impact on muscle excitability, how these changes cause clinical phenotypes, and approaches toward therapeutics. PMID:25880512

The PERK arm of the unfolded protein response regulates satellite cell-mediated skeletal muscle regeneration

PubMed Central

Xiong, Guangyan; Hindi, Sajedah M; Mann, Aman K; Gallot, Yann S; Bohnert, Kyle R; Cavener, Douglas R; Whittemore, Scott R; Kumar, Ashok

2017-01-01

Regeneration of skeletal muscle in adults is mediated by satellite stem cells. Accumulation of misfolded proteins triggers endoplasmic reticulum stress that leads to unfolded protein response (UPR). The UPR is relayed to the cell through the activation of PERK, IRE1/XBP1, and ATF6. Here, we demonstrate that levels of PERK and IRE1 are increased in satellite cells upon muscle injury. Inhibition of PERK, but not the IRE1 arm of the UPR in satellite cells inhibits myofiber regeneration in adult mice. PERK is essential for the survival and differentiation of activated satellite cells into the myogenic lineage. Deletion of PERK causes hyper-activation of p38 MAPK during myogenesis. Blocking p38 MAPK activity improves the survival and differentiation of PERK-deficient satellite cells in vitro and muscle formation in vivo. Collectively, our results suggest that the PERK arm of the UPR plays a pivotal role in the regulation of satellite cell homeostasis during regenerative myogenesis. DOI: http://dx.doi.org/10.7554/eLife.22871.001 PMID:28332979

[Readjustment of the efferent activity of the scratching generator in response to stimulation of muscle afferents of the hindlimb of the decerebrate immobilized cat].

PubMed

Shimanskiĭ, Iu P; Baev, K V

1987-01-01

Rebuildings of the scratching generator activity caused by phasic electrical stimulation of ipsilateral hindlimb muscle nerves during different hindlimb positions were studied in decerebrated immobilized cats. Strong dependence of these rebuildings on the stimulation phase was observed. The character of the "scratch" cycle duration rebuilding was formed by the scratching generator tendency to bring efferent activity into such correlation with the stimulus that the stimulation moment coincided with the moment of efferent activity phase triggering. Phasic altering of the efferent activity intensity rebuilding was observed against a background of "aiming" and "scratching" activity correlation shift in the direction of strengthening activation of muscles innervated by the stimulated nerve. This rebuilding was intensified when the hindlimb deflects from the aimed position in the direction of corresponding muscles stretching. Physiological sense of "rebuilding absence phases" is discussed. It is postulated that absence of the duration and intensity changes can be achieved simultaneously only with definite correlation between phase and intensity of the afferent impulsation burst.

Acid mediates a prolonged antinociception via substance P signaling in acid-induced chronic widespread pain.

PubMed

Chen, Wei-Nan; Chen, Chih-Cheng

2014-05-21

Substance P is an important neuropeptide released from nociceptors to mediate pain signals. We recently revealed antinociceptive signaling by substance P in acid-sensing ion channel 3 (ASIC3)-expressing muscle nociceptors in a mouse model of acid-induced chronic widespread pain. However, methods to specifically trigger the substance P antinociception were still lacking. Here we show that acid could induce antinociceptive signaling via substance P release in muscle. We prevented the intramuscular acid-induced hyperalgesia by pharmacological inhibition of ASIC3 and transient receptor potential V1 (TRPV1). The antinociceptive effect of non-ASIC3, non-TRPV1 acid signaling lasted for 2 days. The non-ASIC3, non-TRPV1 acid antinociception was largely abolished in mice lacking substance P. Moreover, pretreatment with substance P in muscle mimicked the acid antinociceptive effect and prevented the hyperalgesia induced by next-day acid injection. Acid could mediate a prolonged antinociceptive signaling via the release of substance P from muscle afferent neurons in a non-ASIC3, non-TRPV1 manner.

Surface electromyographic mapping of the orbicularis oculi muscle for real-time blink detection.

PubMed

Frigerio, Alice; Cavallari, Paolo; Frigeni, Marta; Pedrocchi, Alessandra; Sarasola, Andrea; Ferrante, Simona

2014-01-01

Facial paralysis is a life-altering condition that significantly impairs function, appearance, and communication. Facial rehabilitation via closed-loop pacing represents a potential but as yet theoretical approach to reanimation. A first critical step toward closed-loop facial pacing in cases of unilateral paralysis is the detection of healthy movements to use as a trigger to prosthetically elicit automatic artificial movements on the contralateral side of the face. To test and to maximize the performance of an electromyography (EMG)-based blink detection system for applications in closed-loop facial pacing. Blinking was detected across the periocular region by means of multichannel surface EMG at an academic neuroengineering and medical robotics laboratory among 15 healthy volunteers. Real-time blink detection was accomplished by mapping the surface of the orbicularis oculi muscle on one side of the face with a multichannel surface EMG. The biosignal from each channel was independently processed; custom software registered a blink when an amplitude-based or slope-based suprathreshold activity was detected. The experiments were performed when participants were relaxed and during the production of particular orofacial movements. An F1 score metric was used to analyze software performance in detecting blinks. The maximal software performance was achieved when a blink was recorded from the superomedial orbit quadrant. At this recording location, the median F1 scores were 0.89 during spontaneous blinking, 0.82 when chewing gum, 0.80 when raising the eyebrows, and 0.70 when smiling. The overall performance of blink detection was significantly better at the superomedial quadrant (F1 score, 0.75) than at the traditionally used inferolateral quadrant (F1 score, 0.40) (P < .05). Electromyographic recording represents an accurate tool to detect spontaneous blinks as part of closed-loop facial pacing systems. The early detection of blink activity may allow real-time pacing via rapid triggering of contralateral muscles. Moreover, an EMG detection system can be integrated in external devices and in implanted neuroprostheses. A potential downside to this approach involves cross talk from adjacent muscles, which can be notably reduced by recording from the superomedial quadrant of the orbicularis oculi muscle and by applying proper signal processing. NA.

Vasoconstriction triggered by hydrogen sulfide: Evidence for Na+,K+,2Cl-cotransport and L-type Ca2+ channel-mediated pathway.

PubMed

Orlov, Sergei N; Gusakova, Svetlana V; Smaglii, Liudmila V; Koltsova, Svetlana V; Sidorenko, Svetalana V

2017-12-01

This study examined the dose-dependent actions of hydrogen sulfide donor sodium hydrosulphide (NaHS) on isometric contractions and ion transport in rat aorta smooth muscle cells (SMC). Isometric contraction was measured in ring aortas segments from male Wistar rats. Activity of Na + /K + -pump and Na + ,K + ,2Cl - cotransport was measured in cultured endothelial and smooth muscle cells from the rat aorta as ouabain-sensitive and ouabain-resistant, bumetanide-sensitive components of the 86 Rb influx, respectively. NaHS exhibited the bimodal action on contractions triggered by modest depolarization ([K + ] o =30 mM). At 10 -4 M, NaHS augmented contractions of intact and endothelium-denuded strips by ~ 15% and 25%, respectively, whereas at concentration of 10 -3  M it decreased contractile responses by more than two-fold. Contractions evoked by 10 -4  M NaHS were completely abolished by bumetanide, a potent inhibitor of Na + ,K + ,2Cl - cotransport, whereas the inhibition seen at 10 -3  M NaHS was suppressed in the presence of K + channel blocker TEA. In cultured SMC, 5×10 -5  M NaHS increased Na + ,K + ,2Cl - - cotransport without any effect on the activity of this carrier in endothelial cells. In depolarized SMC, 45 Ca influx was enhanced in the presence of 10 -4  M NaHS and suppressed under elevation of [NaHS] up to 10 -3  M. 45 Ca influx triggered by 10 -4  M NaHS was abolished by bumetanide and L-type Ca 2+ channel blocker nicardipine. Our results strongly suggest that contractions of rat aortic rings triggered by low doses of NaHS are mediated by activation of Na + ,K + ,2Cl - cotransport and Ca 2+ influx via L-type channels.

Recent advances in our understanding of giant cell arteritis pathogenesis.

PubMed

Samson, Maxime; Corbera-Bellalta, Marc; Audia, Sylvain; Planas-Rigol, Ester; Martin, Laurent; Cid, Maria Cinta; Bonnotte, Bernard

2017-08-01

Giant cell arteritis (GCA) is a granulomatous vasculitis affecting large arteries, especially the aorta and the extracranial branches of the external carotid artery. Its exact pathogenesis is not fully understood but major progress has been made in recent years, leading to new therapeutic targets like inhibition of the interleukin-6 pathway or the modulation of immune checkpoints. The cause of GCA has not been clearly identified but it is thought that GCA occurs on a genetic background and is triggered by unknown environmental factors that could activate and lead to the maturation of dendritic cells localized in the adventitia of normal arteries. These activated dendritic cells then produce chemokines which trigger the recruitment of CD4 + T cells, which in turn become activated, proliferate and polarize into Th1 and Th17 cells, which produce IFN-γ and IL-17, respectively. Exposed to IFN-γ, endothelial cells and vascular smooth muscle cells produce chemokines leading to the recruitment of further Th1 cells, CD8 + T cells and monocytes. The latter differentiate into macrophages, which, when persistently exposed to IFN-γ, form giant cells, the histological hallmark of GCA. With the contribution of vascular smooth muscle cells, immune cells then trigger the destruction and remodeling of the arterial wall, thus leading to the formation of a neo-intima resulting in progressive occlusion of the arterial lumen, which is responsible for the ischemic symptoms of GCA. In this paper, we review recent progress in our understanding of GCA pathogenesis in the fields of genetics, epigenetics, infections, immunology and vascular remodeling. Copyright © 2017 Elsevier B.V. All rights reserved.

Intramuscular nerve distribution of the hamstring muscles: Application to treating spasticity.

PubMed

Rha, Dong-Wook; Yi, Kyu-Ho; Park, Eun Sook; Park, Chunung; Kim, Hee-Jin

2016-09-01

The aim of this article is to elucidate the ideal sites for botulinum toxin injection by examining the intramuscular nerve distributions in the hamstring muscles. The hamstring muscles, biceps femoris, semitendinosus, and semimembranosus (10 specimens each) were stained by the modified Sihler method. The locations of the muscle origins, nerve entry points, and intramuscular arborized areas were recorded as percentages of the total distance from the line crossing the medial and lateral tibial condyles (0%) to the ischial tuberosity (100%). Intramuscular arborization patterns were observed at 15-30% and 50-60% for the biceps femoris, 25-40% and 60-80% for the semitendinosus, and 20-40% for the semimembranosus. This study suggests that botulinum toxin injection for spasticity of the hamstring muscles should be targeted to specific areas. These areas, where the arborization of intramuscular nerve branches is maximal, are recommended as the most effective and safest points for injection. Clin. Anat. 29:746-751, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

EMG parameters and EEG α Index change at fatigue period during different types of muscle contraction

NASA Astrophysics Data System (ADS)

Zhang, Li; Zhou, Bin; Song, Gaoqing

2010-10-01

The purpose of this study is to measure and analyze the characteristics in change of EMG and EEG parameters at muscle fatigue period in participants with different exercise capacity. Twenty participants took part in the tests. They were divided into two groups, Group A (constant exerciser) and Group B (seldom-exerciser). MVC dynamic and 1/3 isometric exercises were performed; EMG and EEG signals were recorded synchronously during different type of muscle contraction. Results indicated that values of MVC, RMS and IEMG in Group A were greater than Group B, but isometric exercise time was shorter than the time of dynamic exercise although its intensity was light. Turning point of IEMG and α Index occurred synchronously during constant muscle contraction of isometric or dynamic exercise. It is concluded that IEMG turning point may be an indication to justify muscle fatigue. Synchronization of EEG and EMG reflects its common characteristics on its bio-electric change.

EMG parameters and EEG α Index change at fatigue period during different types of muscle contraction

NASA Astrophysics Data System (ADS)

Zhang, Li; Zhou, Bin; Song, Gaoqing

2011-03-01

The purpose of this study is to measure and analyze the characteristics in change of EMG and EEG parameters at muscle fatigue period in participants with different exercise capacity. Twenty participants took part in the tests. They were divided into two groups, Group A (constant exerciser) and Group B (seldom-exerciser). MVC dynamic and 1/3 isometric exercises were performed; EMG and EEG signals were recorded synchronously during different type of muscle contraction. Results indicated that values of MVC, RMS and IEMG in Group A were greater than Group B, but isometric exercise time was shorter than the time of dynamic exercise although its intensity was light. Turning point of IEMG and α Index occurred synchronously during constant muscle contraction of isometric or dynamic exercise. It is concluded that IEMG turning point may be an indication to justify muscle fatigue. Synchronization of EEG and EMG reflects its common characteristics on its bio-electric change.

Smart material platforms for miniaturized devices: implications in disease models and diagnostics.

PubMed

Verma, Ritika; Adhikary, Rishi Rajat; Banerjee, Rinti

2016-05-24

Smart materials are responsive to multiple stimuli like light, temperature, pH and redox reactions with specific changes in state. Various functionalities in miniaturised devices can be achieved through the application of "smart materials" that respond to changes in their surroundings. The change in state of the materials in the presence of a stimulus may be used for on demand alteration of flow patterns in devices, acting as microvalves, as scaffolds for cellular aggregation or as modalities for signal amplification. In this review, we discuss the concepts of smart trigger responsive materials and their applications in miniaturized devices both for organ-on-a-chip disease models and for point-of-care diagnostics. The emphasis is on leveraging the smartness of these materials for example, to allow on demand sample actuation, ion dependent spheroid models for cancer or light dependent contractility of muscle films for organ-on-a-chip applications. The review throws light on the current status, scope for technological enhancements, challenges for translation and future prospects of increased incorporation of smart materials as integral parts of miniaturized devices.

Video display terminal operation: a potential risk in the etiology and maintenance of temporomandibular disorders.

PubMed

Horowitz, L; Sarkin, J M

1992-01-01

Surveys indicate over 50 million Americans, mostly women, currently operate video display terminals (VDTs) at home or in the workplace. Recent epidemiological studies reveal more than 75% of approximately 30 million American temporomandibular disorder (TMD) sufferers are women. What does the VDT and TMD have in common besides an affinity for the female gender? TMD is associated with numerous risk factors that commonly initiate sympathetic nervous system and stress hormone response mechanisms resulting in muscle spasms, trigger point formation, and pain in the head and neck. Likewise VDT operation may be linked to three additional sympathetic nervous system irritants including: (1) electrostatic ambient air negative ion depletion, (2) electromagnetic radiation, and (3) eyestrain and postural stress associated with poor work habits and improper work station design. Additional research considering the roles these three factors may play in the etiology of TMD and other myofascial pain problems is indicated. Furthermore, dentists are advised to educate patients as to these possible risks, encourage preventive behaviors on the part of employers and employees, and recommend workplace health, safety, and ergonomic upgrades when indicated.

Dry needling: a literature review with implications for clinical practice guidelines1

PubMed Central

Dunning, James; Butts, Raymond; Mourad, Firas; Young, Ian; Flannagan, Sean; Perreault, Thomas

2014-01-01

Background: Wet needling uses hollow-bore needles to deliver corticosteroids, anesthetics, sclerosants, botulinum toxins, or other agents. In contrast, dry needling requires the insertion of thin monofilament needles, as used in the practice of acupuncture, without the use of injectate into muscles, ligaments, tendons, subcutaneous fascia, and scar tissue. Dry needles may also be inserted in the vicinity of peripheral nerves and/or neurovascular bundles in order to manage a variety of neuromusculoskeletal pain syndromes. Nevertheless, some position statements by several US State Boards of Physical Therapy have narrowly defined dry needling as an ‘intramuscular’ procedure involving the isolated treatment of ‘myofascial trigger points’ (MTrPs). Objectives: To operationalize an appropriate definition for dry needling based on the existing literature and to further investigate the optimal frequency, duration, and intensity of dry needling for both spinal and extremity neuromusculoskeletal conditions. Major findings: According to recent findings in the literature, the needle tip touches, taps, or pricks tiny nerve endings or neural tissue (i.e. ‘sensitive loci’ or ‘nociceptors’) when it is inserted into a MTrP. To date, there is a paucity of high-quality evidence to underpin the use of direct dry needling into MTrPs for the purpose of short and long-term pain and disability reduction in patients with musculoskeletal pain syndromes. Furthermore, there is a lack of robust evidence validating the clinical diagnostic criteria for trigger point identification or diagnosis. High-quality studies have also demonstrated that manual examination for the identification and localization of a trigger point is neither valid nor reliable between-examiners. Conclusions: Several studies have demonstrated immediate or short-term improvements in pain and/or disability by targeting trigger points (TrPs) using in-and-out techniques such as ‘pistoning’ or ‘sparrow pecking’; however, to date, no high-quality, long-term trials supporting in-and-out needling techniques at exclusively muscular TrPs exist, and the practice should therefore be questioned. The insertion of dry needles into asymptomatic body areas proximal and/or distal to the primary source of pain is supported by the myofascial pain syndrome literature. Physical therapists should not ignore the findings of the Western or biomedical ‘acupuncture’ literature that have used the very same ‘dry needles’ to treat patients with a variety of neuromusculoskeletal conditions in numerous, large scale randomized controlled trials. Although the optimal frequency, duration, and intensity of dry needling has yet to be determined for many neuromusculoskeletal conditions, the vast majority of dry needling randomized controlled trials have manually stimulated the needles and left them in situ for between 10 and 30 minute durations. Position statements and clinical practice guidelines for dry needling should be based on the best available literature, not a single paradigm or school of thought; therefore, physical therapy associations and state boards of physical therapy should consider broadening the definition of dry needling to encompass the stimulation of neural, muscular, and connective tissues, not just ‘TrPs’. PMID:25143704

[Biomechanics and bio-energetics of smooth muscle contraction. Relation to bronchial hyperreactivity].

PubMed

Coirault, C; Blanc, F X; Chemla, D; Salmeron, S; Lecarpentier, Y

2000-06-01

Mechanical studies of isolated muscle and analysis of molecular actomyosin interactions have improved our understanding of the pathophysiology of airway smooth muscle. Mechanical properties of airway smooth muscle are similar to those of other smooth muscles. Airway smooth muscle exhibits spontaneous intrinsic tone and its maximum shortening velocity (Vmax) is 10-30 fold lower than in striated muscle. Smooth muscle myosin generates step size and elementary force per crossbridge interaction approximately similar to those of skeletal muscle myosin. Special slow cycling crossbridges, termed latch-bridges, have been attributed to myosin light chain dephosphorylation. From a mechanical point of view, it has been shown that airway hyperresponsiveness is characterized by an increased Vmax and an increased shortening capacity, with no significant change in the force-generating capacity.

Mechanisms for greater insulin-stimulated glucose uptake in normal and insulin-resistant skeletal muscle after acute exercise

PubMed Central

2015-01-01

Enhanced skeletal muscle and whole body insulin sensitivity can persist for up to 24–48 h after one exercise session. This review focuses on potential mechanisms for greater postexercise and insulin-stimulated glucose uptake (ISGU) by muscle in individuals with normal or reduced insulin sensitivity. A model is proposed for the processes underlying this improvement; i.e., triggers initiate events that activate subsequent memory elements, which store information that is relayed to mediators, which translate memory into action by controlling an end effector that directly executes increased insulin-stimulated glucose transport. Several candidates are potential triggers or memory elements, but none have been conclusively verified. Regarding potential mediators in both normal and insulin-resistant individuals, elevated postexercise ISGU with a physiological insulin dose coincides with greater Akt substrate of 160 kDa (AS160) phosphorylation without improved proximal insulin signaling at steps from insulin receptor binding to Akt activity. Causality remains to be established between greater AS160 phosphorylation and improved ISGU. The end effector for normal individuals is increased GLUT4 translocation, but this remains untested for insulin-resistant individuals postexercise. Following exercise, insulin-resistant individuals can attain ISGU values similar to nonexercising healthy controls, but after a comparable exercise protocol performed by both groups, ISGU for the insulin-resistant group has been consistently reported to be below postexercise values for the healthy group. Further research is required to fully understand the mechanisms underlying the improved postexercise ISGU in individuals with normal or subnormal insulin sensitivity and to explain the disparity between these groups after similar exercise. PMID:26487009

Neuropeptide secreted from a pacemaker activates neurons to control a rhythmic behavior.

PubMed

Wang, Han; Girskis, Kelly; Janssen, Tom; Chan, Jason P; Dasgupta, Krishnakali; Knowles, James A; Schoofs, Liliane; Sieburth, Derek

2013-05-06

Rhythmic behaviors are driven by endogenous biological clocks in pacemakers, which must reliably transmit timing information to target tissues that execute rhythmic outputs. During the defecation motor program in C. elegans, calcium oscillations in the pacemaker (intestine), which occur about every 50 s, trigger rhythmic enteric muscle contractions through downstream GABAergic neurons that innervate enteric muscles. However, the identity of the timing signal released by the pacemaker and the mechanism underlying the delivery of timing information to the GABAergic neurons are unknown. Here, we show that a neuropeptide-like protein (NLP-40) released by the pacemaker triggers a single rapid calcium transient in the GABAergic neurons during each defecation cycle. We find that mutants lacking nlp-40 have normal pacemaker function, but lack enteric muscle contractions. NLP-40 undergoes calcium-dependent release that is mediated by the calcium sensor, SNT-2/synaptotagmin. We identify AEX-2, the G-protein-coupled receptor on the GABAergic neurons, as the receptor for NLP-40. Functional calcium imaging reveals that NLP-40 and AEX-2/GPCR are both necessary for rhythmic activation of these neurons. Furthermore, acute application of synthetic NLP-40-derived peptide depolarizes the GABAergic neurons in vivo. Our results show that NLP-40 carries the timing information from the pacemaker via calcium-dependent release and delivers it to the GABAergic neurons by instructing their activation. Thus, we propose that rhythmic release of neuropeptides can deliver temporal information from pacemakers to downstream neurons to execute rhythmic behaviors. Copyright © 2013 Elsevier Ltd. All rights reserved.

Combined system for high-time-resolution dual-excitation fluorescence photometry and fluorescence imaging of calcium transients in single normal and diseased skeletal muscle fibers

NASA Astrophysics Data System (ADS)

Uttenweiler, Dietmar; Wojciechowski, Reinhold; Makabe, Makoto; Veigel, Claudia; Fink, Rainer H.

1994-12-01

Fast photometric measurements and video-imaging of fluorescent indicators both are powerful tools in measuring the intracellular free calcium concentration of muscle and many other cells. as photometric systems yield a high temporal resolution, calcium imaging systems have high spatial but significantly reduced temporal resolution. Therefore we have developed an integrated system combining both methods and based mostly on standard components. As a common, sensitive Ca2+- indicator we used the fluorescent probe Fura-2, which is alternatingly excited for ratio measurements at 340/380 nm. We used a commercially available dual excitation photometric system (OSP-3; Olympus) for attaching a CCD-camera and a frame grabber board. To achieve the synchronization we had to design circuitries for external triggering, synchronization and accurate control of the filter changer, which we added to the system. Additionally, the software for a triggered image acquisition was developed. With this integrated setup one can easily switch between the fast photometric mode (ratio frequency 100 Hz) and the imaging mode (ratio frequency 4.17 Hz). The calcium images are correlated with the 25 times faster spot measurements and are analyzed by means of image processing. With this combined system we study release and uptake of calcium ions of normal and diseased skeletal muscle from mdx mice. Such a system will also be important for other cellular studies in which fluorescence indicators are used to monitor similar time dependent alterations as well as changes in cellular distributions of calcium.

Orbital flourine-18-fluorodeoxyglucose positron emission tomography in patients with Graves' disease for evaluation of active inflammation.

PubMed

Uslu-Beşli, Lebriz; Kabasakal, Levent; Sağer, Sait; Cicik, Erdoğan; Asa, Sertaç; Sönmezoğlu, Kerim

2017-11-01

Prediction and early diagnosis of orbitopathy is needed in patients with Graves' disease, especially when radioiodine therapy is planned. Positron emission tomography/computerized tomography (PET/CT) using flourine-18-fluorodeoxyglucose (FDG) is an effective imaging modality in detection of inflammation, however, its ability to detect orbital inflammation has not been well studied. The aim of our study is to determine the ability of FDG PET/CT to detect orbital inflammation related with Graves' disease, identify active orbitopathy, predict the radioiodine-triggered orbitopathy, and find out the effects of radioiodine on orbital inflammation. Total 31 Graves' disease patients and 17 controls were included. All Graves' disease patients underwent cranial FDG PET/CT imaging prior therapy. Radioiodine therapy and post-treatment PET/CT study was applied to 21 patients. PET/CT images of all examinees were evaluated, measuring extraocular muscle maximum standard uptake value (SUVmax) and muscle thickness. FDG uptake was increased in the majority of extraocular muscles in Graves' disease patients in comparison to controls and this increase was found to be irrelevant from muscle thickness. Extraocular muscle SUVmax values did not increase in Graves' orbitopathy patients who received radioiodine under corticosteroid prophylaxis. SUVmax level of all orbital rectus muscles were increased after radioiodine therapy in nonsmokers, whereas no increase was detected in smokers. FDG PET/CT may be helpful in detection of extraocular muscle inflammation and it may show ongoing orbitopathy in early stages of inflammation before anatomical changes occur.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rovetta, Francesca; Interuniversity Institute of Myology; Stacchiotti, Alessandra

Severe poisoning has recently been diagnosed in humans having hip implants composed of cobalt–chrome alloys due to the release of particulate wear debris on polyethylene and ceramic implants which stimulates macrophagic infiltration and destroys bone and soft tissue, leading to neurological, sensorial and muscular impairments. Consistent with this premise, in this study, we focused on the mechanisms underlying the toxicity of Co(II) ions on skeletal muscle using mouse skeletal C2C12 myotubes as an in vitro model. As detected using propidium iodide incorporation, increasing CoCl{sub 2} doses (from 5 to 200 μM) affected the viability of C2C12 myotubes, mainly by cellmore » necrosis, which was attenuated by necrostatin-1, an inhibitor of the necroptotic branch of the death domain receptor signaling pathway. On the other hand, apoptosis was hardly detectable as supported by the lack of caspase-3 and -8 activation, the latter resulting in only faint activation after exposure to higher CoCl{sub 2} doses for prolonged time points. Furthermore, CoCl{sub 2} treatment resulted in atrophy of the C2C12 myotubes which was characterized by the increased expression of HSP25 and GRP94 stress proteins and other typical 'pro-atrophic molecular hallmarks, such as early activation of the NF-kB pathway and down-regulation of AKT phosphorylation, followed by the activation of the proteasome and autophagy systems. Overall, these results suggested that cobalt may impact skeletal muscle homeostasis as an inducer of cell necrosis and myofiber atrophy. - Highlights: • The effects of cobalt on muscle myofibers in vitro were investigated. • Cobalt treatment mainly causes cell necrosis in skeletal C2C12 myotubes. • Cobalt impacts the PI3K/AKT and NFkB pathways and induces cell stress markers. • Cobalt induces atrophy of C2C12 myotubes through the activation of proteasome and autophagy systems. • Co treatment triggers NF-kB and PI3K/AKT pathways in C2C12 myotubes.« less

Investigation of quality of life in mothers of children withcerebral palsy in Iran: association with socio-economic status,marital satisfaction and fatigue.

PubMed

Khayatzadeh, Mohammad Mahani; Rostami, Hamid Reza; Amirsalari, Susan; Karimloo, Masood

2013-05-01

This study aimed to compare the quality of life (QOL) of Mothers of Children with Cerebral Palsy (MCCPs) with mothers of Typically Developing (TD) children as a Control Group (CG). The association of the mediating variables including socio-economic status (SES), marital satisfaction and fatigue with maternal QOL was also evaluated. The MCCPs group consisted of 120 mothers (mean age: 30.3 ± 5.5 years) of children with CP. The CG included 100 mothers (mean age: 29.9 ± 4.5 years) of TD children. Demographic characteristics of the participants were recorded and the data was collected by World Health Organization Quality of Life-BREF (WHOQOL-BREF), SES Questionnaire, Index of Marital Satisfaction (IMS) and Fatigue Severity Scale-Persian (FSS-P). Data analysis was done by SPSS version 16.0. The QOL and SES were lower, while FSS-P and IMS were higher in MCCPs group than CG (p < 0.001). The SES, IMS and FSS-P associated with all domains of QOL in MCCPs group, while they did just with some domains of QOL in CG (p < 0.05). The lower QOL in MCCPs group is supposed to be mediated by the SES, marital satisfaction and fatigue so, maternal empowerment in terms of these mediators and family-centered approach are recommended. • Improper activity of trapezius muscle motor units can be a reason of the cervicogenic headache. • Increased muscle tension at rest can lead to decrease of its contractile properties. • Rehabilitation of patients is effective when includes first postisometric relaxation procedures and myofascial mobilization of trigger points, then head protraction and retraction exercises according to McKenzie therapy and finally muscles strengthening exercises supplemented with self-control of the correct body posture.

Physiology of a microgravity environment invited review: microgravity and skeletal muscle

NASA Technical Reports Server (NTRS)

Fitts, R. H.; Riley, D. R.; Widrick, J. J.

2000-01-01

Spaceflight (SF) has been shown to cause skeletal muscle atrophy; a loss in force and power; and, in the first few weeks, a preferential atrophy of extensors over flexors. The atrophy primarily results from a reduced protein synthesis that is likely triggered by the removal of the antigravity load. Contractile proteins are lost out of proportion to other cellular proteins, and the actin thin filament is lost disproportionately to the myosin thick filament. The decline in contractile protein explains the decrease in force per cross-sectional area, whereas the thin-filament loss may explain the observed postflight increase in the maximal velocity of shortening in the type I and IIa fiber types. Importantly, the microgravity-induced decline in peak power is partially offset by the increased fiber velocity. Muscle velocity is further increased by the microgravity-induced expression of fast-type myosin isozymes in slow fibers (hybrid I/II fibers) and by the increased expression of fast type II fiber types. SF increases the susceptibility of skeletal muscle to damage, with the actual damage elicited during postflight reloading. Evidence in rats indicates that SF increases fatigability and reduces the capacity for fat oxidation in skeletal muscles. Future studies will be required to establish the cellular and molecular mechanisms of the SF-induced muscle atrophy and functional loss and to develop effective exercise countermeasures.

Subcutaneous immunoglobulin preserves muscle strength in chronic inflammatory demyelinating polyneuropathy.

PubMed

Markvardsen, L H; Harbo, T; Sindrup, S H; Christiansen, I; Andersen, H; Jakobsen, J

2014-12-01

Subcutaneous immunoglobulin (SCIG) is superior to placebo treatment for maintenance of muscle strength during 12 weeks in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). The present study evaluated whether SCIG preserves muscle strength for 1 year in an open-label follow-up study. Seventeen responders to intravenous immunoglobulin (IVIG) who had participated in the previous study of SCIG versus placebo in CIDP were included. After one IVIG infusion 2 weeks prior to baseline, all continued on SCIG treatment at weekly equal dosage and were evaluated after 3, 6 and 12 months. Primary end-points were changes in muscle strength evaluated by isokinetic dynamometry in four affected muscle groups and a composite score of muscle performance and function tests, including Medical Research Council (MRC) score, grip strength, 40-m walking test (40-MWT) and nine-hole peg test (9-HPT). Secondary end-points were changes of each of the listed parameters at each time point as well as an overall disability sum score (ODSS). The dose of SCIG was significantly unaltered during the follow-up period. Overall the isokinetic dynamometry value increased by 7.2% (P = 0.033) and after 3, 6 and 12 months by 5.7%, 8.2% and 6.8% (ns). The overall composite score at all time intervals and for each interval remained unchanged. Amongst the secondary parameters the MRC score increased significantly by 1.7% (P = 0.007), whereas grip strength, 40-MWT, 9-HPT and ODSS remained unchanged. SCIG preserves muscle strength and functional ability in patients with CIDP who previously responded to IVIG. SCIG should be considered as an alternative in long-term treatment of CIDP patients. © 2014 The Author(s) European Journal of Neurology © 2014 EAN.

GABAergic Neurons of the Central Amygdala Promote Cataplexy.

PubMed

Mahoney, Carrie E; Agostinelli, Lindsay J; Brooks, Jessica N K; Lowell, Bradford B; Scammell, Thomas E

2017-04-12

Narcolepsy is characterized by chronic sleepiness and cataplexy-sudden muscle paralysis triggered by strong, positive emotions. This condition is caused by a lack of orexin (hypocretin) signaling, but little is known about the neural mechanisms that mediate cataplexy. The amygdala regulates responses to rewarding stimuli and contains neurons active during cataplexy. In addition, lesions of the amygdala reduce cataplexy. Because GABAergic neurons of the central nucleus of the amygdala (CeA) target brainstem regions known to regulate muscle tone, we hypothesized that these cells promote emotion-triggered cataplexy. We injected adeno-associated viral vectors coding for Cre-dependent DREADDs or a control vector into the CeA of orexin knock-out mice crossed with vGAT-Cre mice, resulting in selective expression of the excitatory hM3 receptor or the inhibitory hM4 receptor in GABAergic neurons of the CeA. We measured sleep/wake behavior and cataplexy after injection of saline or the hM3/hM4 ligand clozapine -N- oxide (CNO) under baseline conditions and under conditions that should elicit positive emotions. In mice expressing hM3, CNO approximately doubled the amount of cataplexy in the first 3 h after dosing under baseline conditions. Rewarding stimuli (chocolate or running wheels) also increased cataplexy, but CNO produced no further increase. In mice expressing hM4, CNO reduced cataplexy in the presence of chocolate or running wheels. These results demonstrate that GABAergic neurons of the CeA are sufficient and necessary for the production of cataplexy in mice, and they likely are a key part of the mechanism through which positive emotions trigger cataplexy. SIGNIFICANCE STATEMENT Cataplexy is one of the major symptoms of narcolepsy, but little is known about how strong, positive emotions trigger these episodes of muscle paralysis. Prior research shows that amygdala neurons are active during cataplexy and cataplexy is reduced by lesions of the amygdala. We found that cataplexy is substantially increased by selective activation of GABAergic neurons in the central nucleus of the amygdala (CeA). We also demonstrate that inhibition of these neurons reduces reward-promoted cataplexy. These results build upon prior work to establish the CeA as a crucial element in the neural mechanisms of cataplexy. These results demonstrate the importance of the CeA in regulating responses to rewarding stimuli, shedding light on the broader neurobiology of emotions and motor control. Copyright © 2017 the authors 0270-6474/17/373995-12$15.00/0.

Effects of leucine and its metabolite β-hydroxy-β-methylbutyrate on human skeletal muscle protein metabolism

PubMed Central

Wilkinson, D J; Hossain, T; Hill, D S; Phillips, B E; Crossland, H; Williams, J; Loughna, P; Churchward-Venne, T A; Breen, L; Phillips, S M; Etheridge, T; Rathmacher, J A; Smith, K; Szewczyk, N J; Atherton, P J

2013-01-01

Maintenance of skeletal muscle mass is contingent upon the dynamic equilibrium (fasted losses–fed gains) in protein turnover. Of all nutrients, the single amino acid leucine (Leu) possesses the most marked anabolic characteristics in acting as a trigger element for the initiation of protein synthesis. While the mechanisms by which Leu is ‘sensed’ have been the subject of great scrutiny, as a branched-chain amino acid, Leu can be catabolized within muscle, thus posing the possibility that metabolites of Leu could be involved in mediating the anabolic effect(s) of Leu. Our objective was to measure muscle protein anabolism in response to Leu and its metabolite HMB. Using [1,2-13C2]Leu and [2H5]phenylalanine tracers, and GC-MS/GC-C-IRMS we studied the effect of HMB or Leu alone on MPS (by tracer incorporation into myofibrils), and for HMB we also measured muscle proteolysis (by arteriovenous (A–V) dilution). Orally consumed 3.42 g free-acid (FA-HMB) HMB (providing 2.42 g of pure HMB) exhibited rapid bioavailability in plasma and muscle and, similarly to 3.42 g Leu, stimulated muscle protein synthesis (MPS; HMB +70%vs. Leu +110%). While HMB and Leu both increased anabolic signalling (mechanistic target of rapamycin; mTOR), this was more pronounced with Leu (i.e. p70S6K1 signalling ≤90 min vs. ≤30 min for HMB). HMB consumption also attenuated muscle protein breakdown (MPB; −57%) in an insulin-independent manner. We conclude that exogenous HMB induces acute muscle anabolism (increased MPS and reduced MPB) albeit perhaps via distinct, and/or additional mechanism(s) to Leu. PMID:23551944

Ultra-structural time-course study in the C. elegans model for Duchenne muscular dystrophy highlights a crucial role for sarcomere-anchoring structures and sarcolemma integrity in the earliest steps of the muscle degeneration process.

PubMed

Brouilly, Nicolas; Lecroisey, Claire; Martin, Edwige; Pierson, Laura; Mariol, Marie-Christine; Qadota, Hiroshi; Labouesse, Michel; Streichenberger, Nathalie; Mounier, Nicole; Gieseler, Kathrin

2015-11-15

Duchenne muscular dystrophy (DMD) is a genetic disease characterized by progressive muscle degeneration due to mutations in the dystrophin gene. In spite of great advances in the design of curative treatments, most patients currently receive palliative therapies with steroid molecules such as prednisone or deflazacort thought to act through their immunosuppressive properties. These molecules only slightly slow down the progression of the disease and lead to severe side effects. Fundamental research is still needed to reveal the mechanisms involved in the disease that could be exploited as therapeutic targets. By studying a Caenorhabditis elegans model for DMD, we show here that dystrophin-dependent muscle degeneration is likely to be cell autonomous and affects the muscle cells the most involved in locomotion. We demonstrate that muscle degeneration is dependent on exercise and force production. Exhaustive studies by electron microscopy allowed establishing for the first time the chronology of subcellular events occurring during the entire process of muscle degeneration. This chronology highlighted the crucial role for dystrophin in stabilizing sarcomeric anchoring structures and the sarcolemma. Our results suggest that the disruption of sarcomeric anchoring structures and sarcolemma integrity, observed at the onset of the muscle degeneration process, triggers subcellular consequences that lead to muscle cell death. An ultra-structural analysis of muscle biopsies from DMD patients suggested that the chronology of subcellular events established in C. elegans models the pathogenesis in human. Finally, we found that the loss of sarcolemma integrity was greatly reduced after prednisone treatment suggesting a role for this molecule in plasma membrane stabilization. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Calcium influx through L-type channels attenuates skeletal muscle contraction via inhibition of adenylyl cyclases.

PubMed

Menezes-Rodrigues, Francisco Sandro; Pires-Oliveira, Marcelo; Duarte, Thiago; Paredes-Gamero, Edgar Julian; Chiavegatti, Tiago; Godinho, Rosely Oliveira

2013-11-15

Skeletal muscle contraction is triggered by acetylcholine induced release of Ca(2+) from sarcoplasmic reticulum. Although this signaling pathway is independent of extracellular Ca(2+), L-type voltage-gated calcium channel (Cav) blockers have inotropic effects on frog skeletal muscles which occur by an unknown mechanism. Taking into account that skeletal muscle fiber expresses Ca(+2)-sensitive adenylyl cyclase (AC) isoforms and that cAMP is able to increase skeletal muscle contraction force, we investigated the role of Ca(2+) influx on mouse skeletal muscle contraction and the putative crosstalk between extracellular Ca(2+) and intracellular cAMP signaling pathways. The effects of Cav blockers (verapamil and nifedipine) and extracellular Ca(2+) chelator EGTA were evaluated on isometric contractility of mouse diaphragm muscle under direct electrical stimulus (supramaximal voltage, 2 ms, 0.1 Hz). Production of cAMP was evaluated by radiometric assay while Ca(2+) transients were assessed by confocal microscopy using L6 cells loaded with fluo-4/AM. Ca(2+) channel blockers verapamil and nifedipine had positive inotropic effect, which was mimicked by removal of extracellular Ca(+2) with EGTA or Ca(2+)-free Tyrode. While phosphodiesterase inhibitor IBMX potentiates verapamil positive inotropic effect, it was abolished by AC inhibitors SQ22536 and NYK80. Finally, the inotropic effect of verapamil was associated with increased intracellular cAMP content and mobilization of intracellular Ca(2+), indicating that positive inotropic effects of Ca(2+) blockers depend on cAMP formation. Together, our results show that extracellular Ca(2+) modulates skeletal muscle contraction, through inhibition of Ca(2+)-sensitive AC. The cross-talk between extracellular calcium and cAMP-dependent signaling pathways appears to regulate the extent of skeletal muscle contraction responses. © 2013 Published by Elsevier B.V.

TRPV1 channel-mediated bilateral allodynia induced by unilateral masseter muscle inflammation in rats.

PubMed

Simonic-Kocijan, Suncana; Zhao, Xuehong; Liu, Wen; Wu, Yuwei; Uhac, Ivone; Wang, KeWei

2013-12-30

Pain in masticatory muscles is among the most prominent symptoms of temperomandibular disorders (TMDs) that have diverse and complex etiology. A common complaint of TMD is that unilateral pain of craniofacial muscle can cause a widespread of bilateral pain sensation, although the underlying mechanism remains unknown. To investigate whether unilateral inflammation of masseter muscle can cause a bilateral allodynia, we generated masseter muscle inflammation induced by unilateral injection of complete Freund's adjuvant (CFA) in rats, and measured the bilateral head withdrawal threshold at different time points using a von Frey anesthesiometer. After behavioral assessment, both right and left trigeminal ganglia (TRG) were dissected and examined for histopathology and transient receptor potential vanilloid 1 (TRPV1) mRNA expression using quantitative real-time PCR analysis. A significant increase in TRPV1 mRNA expression occurred in TRG ipsilateral to CFA injected masseter muscle, whereas no significant alteration in TRPV1 occurred in the contralateral TRG. Interestingly, central injection of TRPV1 antagonist 5-iodoresiniferatoxin into the hippocampus significantly attenuated the head withdrawal response of both CFA injected and non-CFA injected contralateral masseter muscle. Our findings show that unilateral inflammation of masseter muscle is capable of inducing bilateral allodynia in rats. Upregulation of TRPV1 at the TRG level is due to nociception caused by inflammation, whereas contralateral nocifensive behavior in masticatory muscle nociception is likely mediated by central TRPV1, pointing to the involvement of altered information processing in higher centers.

[Characteristics of opening movement in patients with unilateral mastication].

PubMed

Jia, Ling; Wang, Yun; Wang, Mengya

2016-08-01

To analyze characteristics of mandibular movement in patients with unilateral mastication.
 Undergraduate students in oral medicine from Grade 2011 and 2012 in Wannan Medical College were enrolled for this study by cluster sampling method, which include 30 people with unilateral mastication and 30 people with bilateral mastication. The surface electromyogram (sEMG) of masseter muscle and anterovent of digastric muscle were recorded and the trajectory of mandibular incisor point was recorded simultaneously in the maximum opening and closing movement. The results were analyzed by SPSS 19.0 software.
 Average electrical peak of left anterior digastric muscle and right anterior digastric muscle in the unilateral chewing group was lower than that in the bilateral chewing group (P<0.05). The jaw tangent point trajectory was separate in the unilateral chewing group. There were significant differences at the opening type between the 2 groups. The vertical displacement and the sagittal displacement in the unilateral chewing group were significantly lower than those in the bilateral chewing group (P<0.01). There was significant positive correlation between the average peak potential of masseter muscle and displacement on the right side.
 Average electrical peak of left masseter muscle, left anterior digastric muscle, and right anterior digastric muscle decreases in the unilateral chewing group. Jaw tracking in most people deflects to the working side. Opening and closing jaw tracking is separate in 50% unilateral chewing individuals with the decreased opening degree. Unilateral chewing leads to changes in muscle performance accompanied by trajectory anomalies.

Coexistence of a pectoralis quartus muscle, a supernumerary head of biceps brachii muscle and an accessory head of flexor digitorum profundus muscle.

PubMed

Song, Halim; Kim, Jinu; Yoon, Sang-Pil

2018-05-26

Although anatomical variations in the upper limb are frequent, coexistence of multiple combined variations is rare. During a routine educational dissection at Jeju National University Medical School, three muscular variations were found in a 75-year-old Korean male cadaver, in which a supraclavicular cephalic vein was also found in ipsilateral upper extremity during skinning (Go et al., 2017). Here we describe characteristics of the pectoralis quartus muscle, the supernumerary head of biceps brachii muscle and an accessory head of flexor digitorum profundus muscle, and discuss their coexistence from morphological and embryological points of view.

Assessment of the rotation motion at the papillary muscle short-axis plane with normal subjects by two-dimensional speckle tracking imaging: a basic clinical study.

PubMed

Ni, Xian-Da; Huang, Jun; Hu, Yuan-Ping; Xu, Rui; Yang, Wei-Yu; Zhou, Li-Ming

2013-01-01

The aim of this study was to observe the rotation patterns at the papillary muscle plane in the Left Ventricle(LV) with normal subjects using two-dimensional speckle tracking imaging(2D-STI). We acquired standard of the basal, the papillary muscle and the apical short-axis images of the LV in 64 subjects to estimate the LV rotation motion by 2D-STI. The rotational degrees at the papillary muscle short-axis plane were measured at 15 different time points in the analysis of two heart cycles. There were counterclockwise rotation, clockwise rotation, and counterclockwise to clockwise rotation at the papillary muscle plane in the LV with normal subjects, respectively. The ROC analysis of the rotational degrees was performed at the papillary muscle short-axis plane at the peak LV torsion for predicting whether the turnaround point of twist to untwist motion pattern was located at the papillary muscle level. Sensitivity and specificity were 97% and 67%, respectively, with a cut-off value of 0.34°, and an area under the ROC curve of 0.8. At the peak LV torsion, there was no correlation between the rotational degrees at the papillary muscle short-axis plane and the LVEF in the normal subjects(r = 0.000, p = 0.998). In the study, we conclude that there were three rotation patterns at the papillary muscle short-axis levels, and the transition from basal clockwise rotation to apical counterclockwise rotation is located at the papillary muscle level.

Effect of Vibram FiveFingers Minimalist Shoes on the Abductor Hallucis Muscle.

PubMed

Campitelli, Nicholas A; Spencer, Scott A; Bernhard, Kaitlyn; Heard, Kristen; Kidon, Alan

2016-09-02

This study investigated the effect of Vibram FiveFingers Bikila minimalist shoes on intrinsic foot musculature. We hypothesized that a gradual transition into minimalist shoes will increase the thickness of the abductor hallucis muscle. Forty-one individuals were divided into four groups: control (traditional shod) (n = 9), restricted walking in Vibram FiveFingers (n = 11), running in Vibram FiveFingers (n = 10), and unlimited walking in Vibram FiveFingers (n = 11). At baseline, 12 weeks, and 24 weeks, the thickness of the abductor hallucis muscle was determined using ultrasound. Statistical analysis was performed to determine the significance of differences in muscle thickness at the three different time points. The mean thickness of the abductor hallucis muscle at 24 weeks was significantly greater than that at baseline for the restricted walking (P = .005) and running (P < .001) groups. In the unlimited walking group, the mean thickness of the muscle at 12 weeks was significantly greater than that at baseline (P < .05) but not at 24 weeks. There were no significant differences in muscle thickness among the three time points for the control group (P = .432). This study demonstrated that wearing Vibram FiveFinger Bikila footwear over a controlled period of time, an unlimited amount of time, as well as transitioning runners over a 6-month period of time using the 10% philosophy for increasing mileage, significantly increases intrinsic muscle thickness of the abductor hallucis. The abductor hallucis muscle aids in support of the medial longitudinal arch, and an increase in this muscle thickness may help reduce running-related injuries thought to arise from arch weakness.

On the Transition from Reconsolidation to Extinction of Contextual Fear Memories

ERIC Educational Resources Information Center

Cassini, Lindsey F.; Flavell, Charlotte R.; Amaral, Olavo B.; Lee, Jonathan L. C.

2017-01-01

Retrieval of an associative memory can lead to different phenomena. Brief reexposure sessions tend to trigger reconsolidation, whereas more extended ones trigger extinction. In appetitive and fear cued Pavlovian memories, an intermediate "null point" period has been observed where neither process seems to be engaged. Here we investigated…

Skeletal Muscle and Lymphocyte Mitochondrial Dysfunctions in Septic Shock Trigger ICU-Acquired Weakness and Sepsis-Induced Immunoparalysis.

PubMed

Maestraggi, Quentin; Lebas, Benjamin; Clere-Jehl, Raphaël; Ludes, Pierre-Olivier; Chamaraux-Tran, Thiên-Nga; Schneider, Francis; Diemunsch, Pierre; Geny, Bernard; Pottecher, Julien

2017-01-01

Fundamental events driving the pathological processes of septic shock-induced multiorgan failure (MOF) at the cellular and subcellular levels remain debated. Emerging data implicate mitochondrial dysfunction as a critical factor in the pathogenesis of sepsis-associated MOF. If macrocirculatory and microcirculatory dysfunctions undoubtedly participate in organ dysfunction at the early stage of septic shock, an intrinsic bioenergetic failure, sometimes called "cytopathic hypoxia," perpetuates cellular dysfunction. Short-term failure of vital organs immediately threatens patient survival but long-term recovery is also severely hindered by persistent dysfunction of organs traditionally described as nonvital, such as skeletal muscle and peripheral blood mononuclear cells (PBMCs). In this review, we will stress how and why a persistent mitochondrial dysfunction in skeletal muscles and PBMC could impair survival in patients who overcome the first acute phase of their septic episode. First, muscle wasting protracts weaning from mechanical ventilation, increases the risk of mechanical ventilator-associated pneumonia, and creates a state of ICU-acquired muscle weakness, compelling the patient to bed. Second, failure of the immune system ("immunoparalysis") translates into its inability to clear infectious foci and predisposes the patient to recurrent nosocomial infections. We will finally emphasize how mitochondrial-targeted therapies could represent a realistic strategy to promote long-term recovery after sepsis.

Motor unit activity within the depth of the masseter characterized by an adapted scanning EMG technique.

PubMed

van Dijk, J P; Eiglsperger, U; Hellmann, D; Giannakopoulos, N N; McGill, K C; Schindler, H J; Lapatki, B G

2016-09-01

To study motor unit activity in the medio-lateral extension of the masseter using an adapted scanning EMG technique that allows studying the territories of multiple motor units (MUs) in one scan. We studied the m. masseter of 10 healthy volunteers in whom two scans were performed. A monopolar scanning needle and two pairs of fine-wire electrodes were inserted into the belly of the muscle. The signals of the fine wire electrodes were decomposed into the contribution of single MUs and used as a trigger for the scanning needle. In this manner multiple MU territory scans were obtained simultaneously. We determined 161 MU territories. The maximum number of territories obtained in one scan was 15. The median territory size was 4.0mm. Larger and smaller MU territories were found throughout the muscle. The presented technique showed its feasibility in obtaining multiple MU territories in one scan. MUs were active throughout the depth of the muscle. The distribution of electrical and anatomical size of MUs substantiates the heterogeneous distribution of MUs throughout the muscle volume. This distributed activity may be of functional significance for the stabilization of the muscle during force generation. Copyright © 2016 International Federation of Clinical Neurophysiology. All rights reserved.

New phenotypic aspects of the decidual spiral artery wall during early post-implantation mouse pregnancy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elia, Artemis; Charalambous, Fotini; Georgiades, Pantelis, E-mail: pgeor@ucy.ac.cy

Highlights: Black-Right-Pointing-Pointer Spiral artery (SA) wall remodeling (SAR) is ill-defined and clinically important. Black-Right-Pointing-Pointer SA muscular phenotype prior to and during SAR in mice is underexplored. Black-Right-Pointing-Pointer SA muscular wall consists of contractile and non-contractile components. Black-Right-Pointing-Pointer SA wall non-contractile component may be synthetic smooth muscle. Black-Right-Pointing-Pointer Timing and extent of SA wall contractile component loss is revealed. -- Abstract: During pregnancy the walls of decidual spiral arteries (SAs) undergo clinically important structural modifications crucial for embryo survival/growth and maternal health. However, the mechanisms of SA remodeling (SAR) are poorly understood. Although an important prerequisite to this understanding is knowledgemore » about the phenotype of SA muscular wall prior to and during the beginning of mouse SAR, this remains largely unexplored and was the main aim of this work. Using histological and immunohistochemical techniques, this study shows for the first time that during early mouse gestation, from embryonic day 7.5 (E7.5) to E10.5, the decidual SA muscular coat is not a homogeneous structure, but consists of two concentric layers. The first is a largely one cell-thick sub-endothelial layer of contractile mural cells (positive for {alpha}-smooth muscle actin, calponin and SM22{alpha}) with pericyte characteristics (NG2 positive). The second layer is thicker, and evidence is presented that it may be of the synthetic/proliferative smooth muscle phenotype, based on absence ({alpha}-smooth muscle actin and calponin) or weak (SM22{alpha}) expression of contractile mural cell markers, and presence of synthetic smooth muscle characteristics (expression of non-muscle Myosin heavy chain-IIA and of the cell proliferation marker PCNA). Importantly, immunohistochemistry and morphometrics showed that the contractile mural cell layer although prominent at E7.5-E8.5, becomes drastically reduced by E10.5 and is undetectable by E12.5. In conclusion, this study reveals novel aspects of the decidual SA muscular coat phenotype prior to and during early SAR that may have important implications for understanding the mechanisms of SAR.« less

[Electrocoagulation on a fragment of anterior abdominal rectal muscle for the control of presacral bleeding during rectal resection].

PubMed

Casal Núñez, José Enrique; Martínez, María Teresa García; Poblador, Alejandro Ruano

2012-03-01

Presacral venous haemorrhage during rectal movement is low, but is often massive, and even fatal. Our objective is the "in vitro" determination of the results of electrocoagulation applied to a fragment of muscle on the sacral bone surface during rectal resection due to a malignant neoplasm of the rectum. Single-pole coagulation was applied "in vitro" with the selector at maximum power on a 2×2 cms muscle fragment, applied to the anterior side of the IV sacral vertebra until reaching boiling point. The method was used on 6 patients with bleeding of the presacral venous plexus. In the "in vitro" study, boiling point was reached in 90 seconds from applying the single-pole current on the muscle fragment. Electrocoagulation was applied to a 2×2 cm rectal muscle fragment in 6 patients with presacral venous haemorrhage, using pressure on the surface of the presacral bone, with the stopping of the bleeding being achieved in all cases. The use of indirect electrocoagulation on a fragment of the rectus abdominis muscle is a straightforward and highly effective technique for controlling presacral venous haemorrhage. Copyright © 2011 AEC. Published by Elsevier Espana. All rights reserved.

Rejecting the equilibrium-point hypothesis.

PubMed

Gottlieb, G L

1998-01-01

The lambda version of the equilibrium-point (EP) hypothesis as developed by Feldman and colleagues has been widely used and cited with insufficient critical understanding. This article offers a small antidote to that lack. First, the hypothesis implicitly, unrealistically assumes identical transformations of lambda into muscle tension for antagonist muscles. Without that assumption, its definitions of command variables R, C, and lambda are incompatible and an EP is not defined exclusively by R nor is it unaffected by C. Second, the model assumes unrealistic and unphysiological parameters for the damping properties of the muscles and reflexes. Finally, the theory lacks rules for two of its three command variables. A theory of movement should offer insight into why we make movements the way we do and why we activate muscles in particular patterns. The EP hypothesis offers no unique ideas that are helpful in addressing either of these questions.

Progesterone signalling in broiler skeletal muscle is associated with divergent feed efficiency.

PubMed

Bottje, Walter; Kong, Byung-Whi; Reverter, Antonio; Waardenberg, Ashley J; Lassiter, Kentu; Hudson, Nicholas J

2017-02-24

We contrast the pectoralis muscle transcriptomes of broilers selected from within a single genetic line expressing divergent feed efficiency (FE) in an effort to improve our understanding of the mechanistic basis of FE. Application of a virtual muscle model to gene expression data pointed to a coordinated reduction in slow twitch muscle isoforms of the contractile apparatus (MYH15, TPM3, MYOZ2, TNNI1, MYL2, MYOM3, CSRP3, TNNT2), consistent with diminishment in associated slow machinery (myoglobin and phospholamban) in the high FE animals. These data are in line with the repeated transition from red slow to white fast muscle fibres observed in agricultural species selected on mass and FE. Surprisingly, we found that the expression of 699 genes encoding the broiler mitoproteome is modestly-but significantly-biased towards the high FE group, suggesting a slightly elevated mitochondrial content. This is contrary to expectation based on the slow muscle isoform data and theoretical physiological capacity arguments. Reassuringly, the extreme 40 most DE genes can successfully cluster the 12 individuals into the appropriate FE treatment group. Functional groups contained in this DE gene list include metabolic proteins (including opposing patterns of CA3 and CA4), mitochondrial proteins (CKMT1A), oxidative status (SEPP1, HIG2A) and cholesterol homeostasis (APOA1, INSIG1). We applied a differential network method (Regulatory Impact Factors) whose aim is to use patterns of differential co-expression to detect regulatory molecules transcriptionally rewired between the groups. This analysis clearly points to alterations in progesterone signalling (via the receptor PGR) as the major driver. We show the progesterone receptor localises to the mitochondria in a quail muscle cell line. Progesterone is sometimes used in the cattle industry in exogenous hormone mixes that lead to a ~20% increase in FE. Because the progesterone receptor can localise to avian mitochondria, our data continue to point to muscle mitochondrial metabolism as an important component of the phenotypic expression of variation in broiler FE.

Clinical features and predictors for disease natural progression in adults with Pompe disease: a nationwide prospective observational study

PubMed Central

2012-01-01

Background Due partly to physicians’ unawareness, many adults with Pompe disease are diagnosed with great delay. Besides, it is not well known which factors influence the rate of disease progression, and thus disease outcome. We delineated the specific clinical features of Pompe disease in adults, and mapped out the distribution and severity of muscle weakness, and the sequence of involvement of the individual muscle groups. Furthermore, we defined the natural disease course and identified prognostic factors for disease progression. Methods We conducted a single-center, prospective, observational study. Muscle strength (manual muscle testing, and hand-held dynamometry), muscle function (quick motor function test), and pulmonary function (forced vital capacity in sitting and supine positions) were assessed every 3–6 months and analyzed using repeated-measures ANOVA. Results Between October 2004 and August 2009, 94 patients aged between 25 and 75 years were included in the study. Although skeletal muscle weakness was typically distributed in a limb-girdle pattern, many patients had unfamiliar features such as ptosis (23%), bulbar weakness (28%), and scapular winging (33%). During follow-up (average 1.6 years, range 0.5-4.2 years), skeletal muscle strength deteriorated significantly (mean declines of −1.3% point/year for manual muscle testing and of −2.6% points/year for hand-held dynamometry; both p<0.001). Longer disease duration (>15 years) and pulmonary involvement (forced vital capacity in sitting position <80%) at study entry predicted faster decline. On average, forced vital capacity in supine position deteriorated by 1.3% points per year (p=0.02). Decline in pulmonary function was consistent across subgroups. Ten percent of patients declined unexpectedly fast. Conclusions Recognizing patterns of common and less familiar characteristics in adults with Pompe disease facilitates timely diagnosis. Longer disease duration and reduced pulmonary function stand out as predictors of rapid disease progression, and aid in deciding whether to initiate enzyme replacement therapy, or when. PMID:23147228

Core Research Program, Year 5

NASA Technical Reports Server (NTRS)

2002-01-01

Dramatic losses of bone mineral density (BMD) and muscle strength are two of the best documented changes observed in humans after prolonged exposure to microgravity. Recovery of muscle upon return to a 1-G environment is well studied, however, far less is known about the rate and completeness of BMD recovery to pre-flight values. Using the mature tail-suspended adult rat model, this proposal will focus on the temporal course of recovery in tibial bone following a 28-d period of skeletal unloading. Through the study of bone density and muscle strength in the same animal, time-points during recovery from simulated microgravity will be identified when bone is at an elevated risk for fracture. These will occur due to the rapid recovery of muscle strength coupled with a slower recovery of bone, producing a significant mismatch in functional strength of these two tissues. Once the time-point of maximal mismatch is defined, various mechanical and pharmacological interventions will be tested at and around this time-point in attempt to minimize the functional difference of bone and muscle. The outcomes of this research will have high relevance for optimizing the rehabilitation of astronauts upon return to Earth, as well as upon landing on the Martian surface before assuming arduous physical tasks. Further. it will impact significantly on rehabilitation issues common to patients experiencing long periods of limb immobilization or bed rest.

Idiopathic scoliosis: the tethered spine II: post-surgical pain.

PubMed

Whyte Ferguson, Lucy

2014-10-01

The treatment of severe chronic pain in young people following surgery for the correction of curvatures of idiopathic scoliosis (IS) is presented through two case histories. Effective treatment involved release of myofascial trigger points (TrPs) known to refer pain into the spine, and treatment of related fascia and joint dysfunction. The TrPs found to be contributing to spinal area pain were located in muscles at some distance from the spine rather than in the paraspinal muscles. Referred pain from these TrPs apparently accounted for pain throughout the base of the neck and thoracolumbar spine. Exploratory surgery was considered for one patient to address pain following rod placement but the second surgery became unnecessary when the pain was controlled with treatment of the myofascial pain and joint dysfunction. The other individual had both scoliosis and hyperkyphosis, had undergone primary scoliosis surgery, and subsequently underwent a second surgery to remove hardware in an attempt to address her persistent pain following the initial surgery (and because of dislodged screws). The second surgery did not, however, reduce her pain. In both cases these individuals, with severe chronic pain following scoliosis corrective surgery, experienced a marked decrease of pain after myofascial treatment. As will be discussed below, despite the fact that a significant minority of individuals who have scoliosis corrective surgery are thought to require a second surgery, and despite the fact that pain is the most common reason leading to such revision surgery, myofascial pain syndrome (MPS) had apparently not previously been considered as a possible factor in their pain. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cobalt triggers necrotic cell death and atrophy in skeletal C2C12 myotubes.

PubMed

Rovetta, Francesca; Stacchiotti, Alessandra; Faggi, Fiorella; Catalani, Simona; Apostoli, Pietro; Fanzani, Alessandro; Aleo, Maria Francesca

2013-09-01

Severe poisoning has recently been diagnosed in humans having hip implants composed of cobalt-chrome alloys due to the release of particulate wear debris on polyethylene and ceramic implants which stimulates macrophagic infiltration and destroys bone and soft tissue, leading to neurological, sensorial and muscular impairments. Consistent with this premise, in this study, we focused on the mechanisms underlying the toxicity of Co(II) ions on skeletal muscle using mouse skeletal C2C12 myotubes as an in vitro model. As detected using propidium iodide incorporation, increasing CoCl2 doses (from 5 to 200μM) affected the viability of C2C12 myotubes, mainly by cell necrosis, which was attenuated by necrostatin-1, an inhibitor of the necroptotic branch of the death domain receptor signaling pathway. On the other hand, apoptosis was hardly detectable as supported by the lack of caspase-3 and -8 activation, the latter resulting in only faint activation after exposure to higher CoCl2 doses for prolonged time points. Furthermore, CoCl2 treatment resulted in atrophy of the C2C12 myotubes which was characterized by the increased expression of HSP25 and GRP94 stress proteins and other typical `pro-atrophic molecular hallmarks, such as early activation of the NF-kB pathway and down-regulation of AKT phosphorylation, followed by the activation of the proteasome and autophagy systems. Overall, these results suggested that cobalt may impact skeletal muscle homeostasis as an inducer of cell necrosis and myofiber atrophy. Copyright © 2013 Elsevier Inc. All rights reserved.

Inhibition of Stat3 activation suppresses caspase-3 and the ubiquitin-proteasome system, leading to preservation of muscle mass in cancer cachexia.

PubMed

Silva, Kleiton Augusto Santos; Dong, Jiangling; Dong, Yanjun; Dong, Yanlan; Schor, Nestor; Tweardy, David J; Zhang, Liping; Mitch, William E

2015-04-24

Cachexia occurs in patients with advanced cancers. Despite the adverse clinical impact of cancer-induced muscle wasting, pathways causing cachexia are controversial, and clinically reliable therapies are not available. A trigger of muscle protein loss is the Jak/Stat pathway, and indeed, we found that conditioned medium from C26 colon carcinoma (C26) or Lewis lung carcinoma cells activates Stat3 (p-Stat3) in C2C12 myotubes. We identified two proteolytic pathways that are activated in muscle by p-Stat3; one is activation of caspase-3, and the other is p-Stat3 to myostatin, MAFbx/Atrogin-1, and MuRF-1 via CAAT/enhancer-binding protein δ (C/EBPδ). Using sequential deletions of the caspase-3 promoter and CHIP assays, we determined that Stat3 activation increases caspase-3 expression in C2C12 cells. Caspase-3 expression and proteolytic activity were stimulated by p-Stat3 in muscles of tumor-bearing mice. In mice with cachexia caused by Lewis lung carcinoma or C26 tumors, knock-out of p-Stat3 in muscle or with a small chemical inhibitor of p-Stat3 suppressed muscle mass losses, improved protein synthesis and degradation in muscle, and increased body weight and grip strength. Activation of p-Stat3 stimulates a pathway from C/EBPδ to myostatin and expression of MAFbx/Atrogin-1 and increases the ubiquitin-proteasome system. Indeed, C/EBPδ KO decreases the expression of MAFbx/Atrogin-1 and myostatin, while increasing muscle mass and grip strength. In conclusion, cancer stimulates p-Stat3 in muscle, activating protein loss by stimulating caspase-3, myostatin, and the ubiquitin-proteasome system. These results could lead to novel strategies for preventing cancer-induced muscle wasting. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Inhibition of Stat3 Activation Suppresses Caspase-3 and the Ubiquitin-Proteasome System, Leading to Preservation of Muscle Mass in Cancer Cachexia*

PubMed Central

Silva, Kleiton Augusto Santos; Dong, Jiangling; Dong, Yanjun; Dong, Yanlan; Schor, Nestor; Tweardy, David J.; Zhang, Liping; Mitch, William E.

2015-01-01

Cachexia occurs in patients with advanced cancers. Despite the adverse clinical impact of cancer-induced muscle wasting, pathways causing cachexia are controversial, and clinically reliable therapies are not available. A trigger of muscle protein loss is the Jak/Stat pathway, and indeed, we found that conditioned medium from C26 colon carcinoma (C26) or Lewis lung carcinoma cells activates Stat3 (p-Stat3) in C2C12 myotubes. We identified two proteolytic pathways that are activated in muscle by p-Stat3; one is activation of caspase-3, and the other is p-Stat3 to myostatin, MAFbx/Atrogin-1, and MuRF-1 via CAAT/enhancer-binding protein δ (C/EBPδ). Using sequential deletions of the caspase-3 promoter and CHIP assays, we determined that Stat3 activation increases caspase-3 expression in C2C12 cells. Caspase-3 expression and proteolytic activity were stimulated by p-Stat3 in muscles of tumor-bearing mice. In mice with cachexia caused by Lewis lung carcinoma or C26 tumors, knock-out of p-Stat3 in muscle or with a small chemical inhibitor of p-Stat3 suppressed muscle mass losses, improved protein synthesis and degradation in muscle, and increased body weight and grip strength. Activation of p-Stat3 stimulates a pathway from C/EBPδ to myostatin and expression of MAFbx/Atrogin-1 and increases the ubiquitin-proteasome system. Indeed, C/EBPδ KO decreases the expression of MAFbx/Atrogin-1 and myostatin, while increasing muscle mass and grip strength. In conclusion, cancer stimulates p-Stat3 in muscle, activating protein loss by stimulating caspase-3, myostatin, and the ubiquitin-proteasome system. These results could lead to novel strategies for preventing cancer-induced muscle wasting. PMID:25787076

8-Bromo-cAMP decreases the Ca2+ sensitivity of airway smooth muscle contraction through a mechanism distinct from inhibition of Rho-kinase.

PubMed

Endou, Katsuaki; Iizuka, Kunihiko; Yoshii, Akihiro; Tsukagoshi, Hideo; Ishizuka, Tamotsu; Dobashi, Kunio; Nakazawa, Tsugio; Mori, Masatomo

2004-10-01

To clarify whether cyclic AMP (cAMP)/cAMP-dependent protein kinase (PKA) activation and Rho-kinase inhibition share a common mechanism to decrease the Ca2+ sensitivity of airway smooth muscle contraction, we examined the effects of 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP), a stable cAMP analog, and (+)-(R)-trans-4-(1-aminoethyl)-N-(4-pyridyl) cyclohexane carboxamide dihydrochloride, monohydrate (Y-27632), a Rho-kinase inhibitor, on carbachol (CCh)-, guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS)-, 4beta-phorbol 12,13-dibutyrate (PDBu)-, and leukotriene D4 (LTD4)-induced Ca2+ sensitization in alpha-toxin-permeabilized rabbit tracheal and human bronchial smooth muscle. In rabbit trachea, CCh-induced smooth muscle contraction was inhibited by 8-BrcAMP and Y-27632 to a similar extent. However, GTPgammaS-induced smooth muscle contraction was resistant to 8-BrcAMP. In the presence of a saturating concentration of Y-27632, PDBu-induced smooth muscle contraction was completely reversed by 8-BrcAMP. Conversely, PDBu-induced smooth muscle contraction was resistant to Y-27632. In the presence of a saturating concentration of 8-BrcAMP, GTPgammaS-induced Ca2+ sensitization was also reversed by Y-27632. The 8-BrcAMP had no effect on the ATP-triggered contraction of tracheal smooth muscle that had been treated with calyculin A in rigor solutions. The 8-BrcAMP and Y-27632 additively accelerated the relaxation rate of PDBu- and GTPgammaS-treated smooth muscle under myosin light chain kinase-inhibited conditions. In human bronchus, LTD4-induced smooth muscle contraction was inhibited by both 8-BrcAMP and Y-27632. We conclude that cAMP/PKA-induced Ca2+ desensitization contains at least two mechanisms: 1) inhibition of the muscarinic receptor signaling upstream from Rho activation and 2) cAMP/PKA's preferential reversal of PKC-mediated Ca2+ sensitization in airway smooth muscle.

[Vecuronium in dystrophia myotonica (Curschmann-Steinert)].

PubMed

Wruck, G; Tryba, M

1989-05-01

An emergency laparotomy was performed in a 31-year-old female (body wt 48 kg) with known myotonic dystrophy. Premedication with dantrolene (1 mg/kg i.v.) was used to prevent a myotonic response. Muscle relaxation was monitored electromyographically. Following induction with fentanyl (0.3 mg) and thiopental (200 mg), muscle relaxation was achieved with 2 mg vecuronium titrated for about 3 min until the T1-response was reduced to 10%. The recovery time was normal. A repetitive dose of 0.5 mg vecuronium was necessary after 20 min, when the T1 reached 60%. Extubation and the early postoperative period were uneventful. Because of the unknown predisposition of our patient for the development of malignant hyperthermia, anesthesia was performed with trigger-free anesthetics.

Orion Exploration Flight Test-1 Contingency Drogue Deploy Velocity Trigger

NASA Technical Reports Server (NTRS)

Gay, Robert S.; Stochowiak, Susan; Smith, Kelly

2013-01-01

As a backup to the GPS-aided Kalman filter and the Barometric altimeter, an "adjusted" velocity trigger is used during entry to trigger the chain of events that leads to drogue chute deploy for the Orion Multi-Purpose Crew Vehicle (MPCV) Exploration Flight Test-1 (EFT-1). Even though this scenario is multiple failures deep, the Orion Guidance, Navigation, and Control (GN&C) software makes use of a clever technique that was taken from the Mars Science Laboratory (MSL) program, which recently successfully landing the Curiosity rover on Mars. MSL used this technique to jettison the heat shield at the proper time during descent. Originally, Orion use the un-adjusted navigated velocity, but the removal of the Star Tracker to save costs for EFT-1, increased attitude errors which increased inertial propagation errors to the point where the un-adjusted velocity caused altitude dispersions at drogue deploy to be too large. Thus, to reduce dispersions, the velocity vector is projected onto a "reference" vector that represents the nominal "truth" vector at the desired point in the trajectory. Because the navigation errors are largely perpendicular to the truth vector, this projection significantly reduces dispersions in the velocity magnitude. This paper will detail the evolution of this trigger method for the Orion project and cover the various methods tested to determine the reference "truth" vector; and at what point in the trajectory it should be computed.

Cisplatin triggers atrophy of skeletal C2C12 myotubes via impairment of Akt signalling pathway and subsequent increment activity of proteasome and autophagy systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fanzani, Alessandro, E-mail: fanzani@med.unibs.it; Zanola, Alessandra; Rovetta, Francesca

2011-02-01

Cisplatin (cisPt) is an antineoplastic drug which causes an array of adverse effects on different organs and tissues, including skeletal muscle. In this work we show that cisPt behaves as a potent trigger to activate protein hypercatabolism in skeletal C2C12 myotubes. Within 24 h of 50 {mu}M cisPt administration, C2C12 myotubes displayed unchanged cell viability but showed a subset of hallmark signs typically recognized during atrophy, including severe reduction in body size, repression of Akt phosphorylation, transcriptional up-regulation of atrophy-related genes, such as atrogin-1, gabarap, beclin-1 and bnip-3, and loss of myogenic markers. As a consequence, proteasomal activity and formationmore » of autophagosomes were remarkably increased in cisPt-treated myotubes, but forced stimulation of Akt pathway, as obtained through insulin administration or delivery of a constitutively activated Akt form, was sufficient to counter the cisPt-induced protein breakdown, leading to rescue of atrophic size. Overall, these results indicate that cisPt induces atrophy of C2C12 myotubes via activation of proteasome and autophagy systems, suggesting that the Akt pathway represents one sensitive target of cisPt molecular action in skeletal muscle.« less

DJ-1 links muscle ROS production with metabolic reprogramming and systemic energy homeostasis in mice.

PubMed

Shi, Sally Yu; Lu, Shun-Yan; Sivasubramaniyam, Tharini; Revelo, Xavier S; Cai, Erica P; Luk, Cynthia T; Schroer, Stephanie A; Patel, Prital; Kim, Raymond H; Bombardier, Eric; Quadrilatero, Joe; Tupling, A Russell; Mak, Tak W; Winer, Daniel A; Woo, Minna

2015-06-16

Reactive oxygen species (ROS) have been linked to a wide variety of pathologies, including obesity and diabetes, but ROS also act as endogenous signalling molecules, regulating numerous biological processes. DJ-1 is one of the most evolutionarily conserved proteins across species, and mutations in DJ-1 have been linked to some cases of Parkinson's disease. Here we show that DJ-1 maintains cellular metabolic homeostasis via modulating ROS levels in murine skeletal muscles, revealing a role of DJ-1 in maintaining efficient fuel utilization. We demonstrate that, in the absence of DJ-1, ROS uncouple mitochondrial respiration and activate AMP-activated protein kinase, which triggers Warburg-like metabolic reprogramming in muscle cells. Accordingly, DJ-1 knockout mice exhibit higher energy expenditure and are protected from obesity, insulin resistance and diabetes in the setting of fuel surplus. Our data suggest that promoting mitochondrial uncoupling may be a potential strategy for the treatment of obesity-associated metabolic disorders.

Sensing muscle ischemia: coincident detection of acid and ATP via interplay of two ion channels.

PubMed

Birdsong, William T; Fierro, Leonardo; Williams, Frank G; Spelta, Valeria; Naves, Ligia A; Knowles, Michelle; Marsh-Haffner, Josephine; Adelman, John P; Almers, Wolfhard; Elde, Robert P; McCleskey, Edwin W

2010-11-18

Ischemic pain--examples include the chest pain of a heart attack and the leg pain of a 30 s sprint--occurs when muscle gets too little oxygen for its metabolic need. Lactic acid cannot act alone to trigger ischemic pain because the pH change is so small. Here, we show that another compound released from ischemic muscle, adenosine tri-phosphate (ATP), works together with acid by increasing the pH sensitivity of acid-sensing ion channel number 3 (ASIC3), the molecule used by sensory neurons to detect lactic acidosis. Our data argue that ATP acts by binding to P2X receptors that form a molecular complex with ASICs; the receptor on sensory neurons appears to be P2X5, an electrically quiet ion channel. Coincident detection of acid and ATP should confer sensory selectivity for ischemia over other conditions of acidosis. Copyright © 2010 Elsevier Inc. All rights reserved.

Effects of a prior stretching of the plantarflexor muscles on the capacity to control upright stance maintenance in healthy adults.

PubMed

Rougier, Patrice; Burdet, Cyril; Genthon, Nicolas

2006-10-01

To assess whether prior stretching of a muscle can induce improved postural control, 15 healthy adults stood still upright with their eyes closed before and after a series of bilateral stretches of the triceps surae muscles. The analysis focused on the center of pressure (CP) and the vertical projection of the center of gravity (CGv) trajectories and their difference (CP - CGv). The prolonged stretching induced a forward shift of the mean position of the CGv. The frequency analysis showed a constancy of the amplitudes of both basic movements whereas an increased mean power frequency was seen for the CP - CGv movements. A fractional Brownian motion modeling of the trajectories indicates shortest time intervals and lower covered distances by the CGv before a change in its control occurs along the antero-posterior axis. This reorganization is thought to be a result of improved body movement detection, which allows postural control over the longest time intervals to be triggered more rapidly.

Fibromyalgia

MedlinePlus

Fibromyalgia is a disorder that causes muscle pain and fatigue. People with fibromyalgia have "tender points" on the body. Tender points are specific places on the neck, shoulders, back, hips, arms, and ...

Handgrip Strength Cutoff Points to Identify Mobility Limitation in Community-dwelling Older People and Associated Factors.

PubMed

Vasconcelos, K S de Souza; Dias, J M Domingues; Bastone, A de Carvalho; Vieira, R Alvarenga; Andrade, A C de Souza; Perracini, M Rodrigues; Guerra, R Oliveira; Dias, R Corrêa

2016-03-01

Sarcopenia is defined as a progressive and generalized loss of skeletal muscle mass and strength. The specific threshold of muscle weakness that leads to mobility limitations has not been identified. To determine the best cutoff point of handgrip strength for identifying mobility limitation and to investigate the factors associated with muscle weakness and mobility limitation in community-dwelling older people. Transversal study. Cities of Belo Horizonte, Barueri and Santa Cruz in Brazil. 1374 community-dwelling older people from the Frailty study in Brazilian older people (FIBRA Study). Outcomes included muscle weakness determined according to gender-specific handgrip strength cutoff points generated by Receiver Operating Characteristic curves, mobility limitation defined as a gait speed ≤ 0.8 m/s; and a combination of both muscle weakness and mobility limitation. Associated factors included socio-demographic variables, lifestyle, anthropometrics, health conditions, use of health services and disability. The cutoff points of handgrip strength with the best balancing between sensitivity and specificity for mobility limitation were 25.8 kgf for men (sensitivity 69%, specificity 73%) and 17.4 kgf (sensitivity 60%, specificity 66%) for women. Age and disability in instrumental activities of daily living were associated with all outcomes. Women had greater odds of mobility limitation than men. Physical inactivity, body fat, diabetes, depression, sleeping disturbances, number of medications and occurrence of falls remained as significant associated factors in the final model. Handgrip strength can be a useful tool to identify mobility limitation in clinical practice. Interventions to prevent or minimize impacts of sarcopenia should stimulate physical activity and improvement of body composition in addition to the management of chronic diseases and disabilities.

Biomechanical implications of lateral pterygoid contribution to biting and jaw opening in humans.

PubMed

Osborn, J W

1995-12-01

The contributions of the lateral pterygoid muscle to a variety of different tasks were analysed by a linear programming mode based on the equations for static equilibrium in three dimensions and containing 12 muscles. The model was used to study lateral pterygoid activity at maximum bite force (MBF) for changes in (i) the direction and point of application of the bite force, (ii) the orientation of the masseter and medial pterygoid muscles and (iii) the slope of the articular eminence (glenoid slope). The effects on MBF of removing one or both lateral pterygoids were also examined. Lateral pterygoid provided a very important indirect contribution to some clenching forces. Under some conditions removing one lateral pterygoid muscle (simulating guarding an injured muscle) halved the MBF. Its activity at MBF was reduced as masseter was tilted more forward, the glenoid slope was made more horizontal and the bite force was made more vertical. The muscle helped to oppose (balance) the horizontal reaction forces at the bite point and joints, which potentially pushed the condyle backward. A balancing muscle is now defined as one (like lateral pterygoid) whose activity increases the output force by far more than its direct contribution to that force. In a larger model containing 16 muscles, every muscle was most active when its line of action was parallel to the output force. Finally, in a model which divided lateral pterygoid into superior and inferior heads, activity suddenly switched from the superior head to the inferior head when the angle of opening changed from 120 degrees (forward from the vertical) to 140 degrees.

Intraoperative muscle electrical stimulation for accurate positioning of the temporalis muscle tendon during dynamic, one-stage lengthening temporalis myoplasty for facial and lip reanimation.

PubMed

Har-Shai, Yaron; Gil, Tamir; Metanes, Issa; Labbé, Daniel

2010-07-01

Facial paralysis is a significant functional and aesthetic handicap. Facial reanimation is performed either by two-stage microsurgical methods or by regional one-stage muscle pedicle flaps. Labbé has modified and improved the regional muscle pedicle transfer flaps for facial reanimation (i.e., the lengthening temporalis myoplasty procedure). This true myoplasty technique is capable of producing a coordinated, spontaneous, and symmetrical smile. An intraoperative electrical stimulation of the temporal muscle is proposed to simulate the smile of the paralyzed side on the surgical table. The intraoperative electrical stimulation of the temporalis muscle, employing direct percutaneous electrode needles or transcutaneous electrical stimulation electrodes, was utilized in 11 primary and four secondary cases with complete facial palsy. The duration of the facial paralysis was up to 12 years. Postoperative follow-up ranged from 3 to 12 months. The insertion points of the temporalis muscle tendon to the nasolabial fold, upper lip, and oral commissure had been changed according to the intraoperative muscle stimulation in six patients of the 11 primary cases (55 percent) and in all four secondary (revisional) cases. A coordinated, spontaneous, and symmetrical smile was achieved in all patients by 3 months after surgery by employing speech therapy and biofeedback. This adjunct intraoperative refinement provides crucial feedback for the surgeon in both primary and secondary facial palsy cases regarding the vector of action of the temporalis muscle and the accuracy of the anchoring points of its tendon, thus enhancing a more coordinated and symmetrical smile.

Vascular smooth muscle cell apoptosis is an early trigger for hypothyroid atherosclerosis.

PubMed

Wang, Pei; Xu, Tian-Ying; Guan, Yun-Feng; Zhao, Yan; Li, Zhi-Yong; Lan, Xiao-Hong; Wang, Xia; Yang, Peng-Yuan; Kang, Zhi-Min; Vanhoutte, Paul M; Miao, Chao-Yu

2014-06-01

Endothelial dysfunction is an initial and vascular smooth muscle cell (VSMC) apoptosis, a later step of atherosclerosis. Hypothyroidism accelerates atherosclerosis. However, the early events responsible for this pro-atherosclerotic effect are unclear. Rats were resistant to induction of atherosclerosis by high cholesterol diet alone, but became susceptible in hypothyroid state achieved by administration of propylthiouracil (PTU) for 6 weeks. VSMC dysfunction and apoptosis were obvious within 1 week after PTU treatment, without signs of endothelial dysfunction. This early VSMC damage was caused by hypothyroidism but not the high cholesterol diet. In ApoE knockout mice, PTU-induced hypothyroidism triggered early VSMC apoptosis, increased oxidative stress, and accelerated atherosclerosis development. Thyroid hormone supplementation (T4, 10, or 50 μg/kg) prevented atherogenic phenotypes in hypothyroid rats and mice. In rats, thyroidectomy caused severe hypothyroidism 5 days after operation, which also led to rapid VSMC dysfunction and apoptosis. In vitro studies did not show a direct toxic effect of PTU on VSMCs. In contrast, thyroid hormone (T3, 0.75 μg/L plus T4, 50 nmol/L) exerted a direct protection against VSMC apoptosis, which was reduced by knockdown of TRα1, rather than TRβ1 and TRβ2 receptors. TRα1-mediated inhibition of apoptotic signalling of JNKs and caspase-3 contributed to the anti-apoptotic action of thyroid hormone. These findings provide an in vivo example for VSMC apoptosis as an early trigger of hypothyroidism-associated atherosclerosis, and reveal activation of TRα1 receptors to prevent VSMC apoptosis as a therapeutic strategy in this disease. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

The analgesic effect of photobiomodulation therapy (830 nm) on the masticatory muscles: a randomized, double-blind study.

PubMed

Costa, Sabrina Araújo Pinho; Florezi, Giovanna Piacenza; Artes, Gisele Ebling; Costa, Jessica Ribeiro da; Gallo, Rosane Tronchin; Freitas, Patricia Moreira de; Witzel, Andrea Lusvarghi

2017-12-18

This study assesses the efficacy of photobiomodulation therapy (830 nm) for myalgia treatment of masticatory muscles. Sixty patients with muscular myalgia were selected and randomly allocated into 2 groups (n=30): Group A comprised patients given a placebo (control), and Group B consisted of those undergoing photobiomodulation therapy (PBMT). PBMT and placebo were applied bilaterally to specific points on the masseter and temporal muscles. Referred pain elicited by palpation and maximum mouth opening were measured before (EV1) and after (EV2) the treatments. The data were analyzed using statistical tests, considering a significance level of 5%. No significant differences in range were observed for active or passive mouth opening (p ≥ 0.05). Comparing the final outcomes (EV1-EV2) of both treatments, statistical significance was verified for total pain in the right masseter muscle (p = 0.001) and total pain (p = 0.005). In EV2, significant differences in pain reported with palpation were found between Groups A and B for the following: left posterior temporal muscle (p = 0.025), left superior masseter muscle (p = 0.036), inferior masseter muscle (p = 0.021), total pain (left side) (p = 0.009), total masseter muscle (left side) (p = 0.014), total temporal (left side) (p = 0.024), and total pain (p = 0.035). We concluded that PBMT (830 nm) reduces pain in algic points, but does not influence the extent of mouth opening in patients with myalgia.

Assessment of the Rotation Motion at the Papillary Muscle Short-Axis Plane with Normal Subjects by Two-Dimensional Speckle Tracking Imaging: A Basic Clinical Study

PubMed Central

Ni, Xian-Da; Huang, Jun; Hu, Yuan-Ping; Xu, Rui; Yang, Wei-Yu; Zhou, Li-Ming

2013-01-01

Background The aim of this study was to observe the rotation patterns at the papillary muscle plane in the Left Ventricle(LV) with normal subjects using two-dimensional speckle tracking imaging(2D-STI). Methods We acquired standard of the basal, the papillary muscle and the apical short-axis images of the LV in 64 subjects to estimate the LV rotation motion by 2D-STI. The rotational degrees at the papillary muscle short-axis plane were measured at 15 different time points in the analysis of two heart cycles. Results There were counterclockwise rotation, clockwise rotation, and counterclockwise to clockwise rotation at the papillary muscle plane in the LV with normal subjects, respectively. The ROC analysis of the rotational degrees was performed at the papillary muscle short-axis plane at the peak LV torsion for predicting whether the turnaround point of twist to untwist motion pattern was located at the papillary muscle level. Sensitivity and specificity were 97% and 67%, respectively, with a cut-off value of 0.34°, and an area under the ROC curve of 0.8. At the peak LV torsion, there was no correlation between the rotational degrees at the papillary muscle short-axis plane and the LVEF in the normal subjects(r = 0.000, p = 0.998). Conclusions In the study, we conclude that there were three rotation patterns at the papillary muscle short-axis levels, and the transition from basal clockwise rotation to apical counterclockwise rotation is located at the papillary muscle level. PMID:24376634

Oxidative and proteolysis-related parameters of skeletal muscle from hamsters with experimental pulmonary emphysema: a comparison between papain and elastase induction.

PubMed

Brunnquell, Cláudia R; Vieira, Nichelle A; Sábio, Laís R; Sczepanski, Felipe; Cecchini, Alessandra L; Cecchini, Rubens; Guarnier, Flávia A

2015-06-01

The objective of this study was to investigate whether emphysema induced by elastase or papain triggers the same effects on skeletal muscle, related to oxidative stress and proteolysis, in hamsters. For this purpose, we evaluated pulmonary lesions, body weight, muscle loss, oxidative stress (thiobarbituric acid-reactive substances, total and oxidized glutathiones, chemiluminescence stimulated by tert-butyl hydroperoxide and carbonyl proteins), chymotrypsin-like and calpain-like proteolytic activities and muscle fibre cross-sectional area in the gastrocnemius muscles of emphysemic hamsters. Two groups of animals received different intratracheal inductions of experimental emphysema: by 40 mg/ml papain (EP) or 5.2 IU/100 g animal (EE) elastase (n = 10 animals/group). The control group received intratracheal instillation of 300 μl sterile NaCl 0.9%. Compared with the control group, the EP group had reduced muscle weight (18.34%) and the EE group had increased muscle weight (8.37%). Additionally, tert-butyl hydroperoxide-initiated chemiluminescence, carbonylated proteins and chymotrypsin-like proteolytic activity were all elevated in the EP group compared to the CS group, while total glutathione was decreased compared to the EE group. The EE group showed more fibres with increased cross-sectional areas and increased calpain-like activity. Together, these data show that elastase and papain, when used to induce experimental models of emphysema, lead to different speeds and types of adaptation. These findings provide more information on choosing a suitable experimental model for studying skeletal muscle adaptations in emphysema. © 2015 The Authors. International Journal of Experimental Pathology © 2015 International Journal of Experimental Pathology.

[Clinical profile of persistent generalized muscle contraction following the insult of developing brain].

PubMed

Maruyama, Koichi; Iai, Mizue; Arai, Hiroshi; Yokochi, Kenji

2014-01-01

Persons with severe motor and intellectual disabilities (SMID) caused by injury to the developing brain sometimes present generalized hypertonia in a specific position with extreme muscle overactivity persisting for most of the time during wakefulness. This "persistent generalized muscle contraction" is often associated with bad humor, sleep disturbance, hyperhidrosis, wasting, elevation of serum creatine kinase levels, regular daytime use of hypnotic or sedative medication, and the necessity to maintain the neck or hip in a flexed position manually. The aim of this study is to elucidate the clinical profile of this condition. We retrospectively examined the medical records and brain imaging data of 66 SMID patients in the state of persistent generalized muscle contraction. Most patients could be classified into 2 major categories on the basis of clinical presentation and brain imaging: (A) those with premature birth and bilateral lesion of globus pallidus interna (kernicterus) (n = 16), and (B) those with various widespread bilateral basal ganglia/thalamic and/or cerebral lesions such as hypoxia-ischemia, acute encephalopathy, malformation, etc (n = 50). Group A assumed an asymmetrical tonic-neck-reflex-like position, torsion of the trunk, fluctuation of hypertonia, and better mental development. Three of them exhibited extreme hypertonia resembling status dystonicus. Group B often exhibited persistent and fixed retroflexion of the neck and trunk or opisthotonus. Drugs such as oral muscular relaxants were ineffective in both groups. Injection of botulinum toxin into the cervical and paravertebral muscles partially alleviated symptoms. Persistent generalized muscle contraction in SMID has at least two different types. Group A has characteristics of severe dystonic hypertonia that could lead to status dystonicus. Group B might have peculiar characteristics of muscle overactivity triggered by wakefulness or discomfort, which probably results from inability to achieve spontaneous muscle relaxation.

Regulation of Contraction by the Thick Filaments in Skeletal Muscle.

PubMed

Irving, Malcolm

2017-12-19

Contraction of skeletal muscle cells is initiated by a well-known signaling pathway. An action potential in a motor nerve triggers an action potential in a muscle cell membrane, a transient increase of intracellular calcium concentration, binding of calcium to troponin in the actin-containing thin filaments, and a structural change in the thin filaments that allows myosin motors from the thick filaments to bind to actin and generate force. This calcium/thin filament mediated pathway provides the "START" signal for contraction, but it is argued that the functional response of the muscle cell, including the speed of its contraction and relaxation, adaptation to the external load, and the metabolic cost of contraction is largely determined by additional mechanisms. This review considers the role of the thick filaments in those mechanisms, and puts forward a paradigm for the control of contraction in skeletal muscle in which both the thick and thin filaments have a regulatory function. The OFF state of the thick filament is characterized by helical packing of most of the myosin head or motor domains on the thick filament surface in a conformation that makes them unavailable for actin binding or ATP hydrolysis, although a small fraction of the myosin heads are constitutively ON. The availability of the majority fraction of the myosin heads for contraction is controlled in part by the external load on the muscle, so that these heads only attach to actin and hydrolyze ATP when they are required. This phenomenon seems to be the major determinant of the well-known force-velocity relationship of muscle, and controls the metabolic cost of contraction. The regulatory state of the thick filament also seems to control the dynamics of both muscle activation and relaxation. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Gain of postural responses increases in response to real and anticipated pain.

PubMed

Hodges, Paul W; Tsao, Henry; Sims, Kevin

2015-09-01

This study tested two contrasting theories of adaptation of postural control to pain. One proposes alteration to the postural strategy including inhibition of muscles that produce painful movement; another proposes amplification of the postural adjustment to recruit strategies normally reserved for higher load. This study that aimed to determine which of these alternatives best explains pain-related adaptation of the hip muscle activity associated with stepping down from steps of increasing height adaptation of postural control to increasing load was evaluated from hip muscle electromyography (fine-wire and surface electrodes) as ten males stepped from steps of increasing height (i.e. increasing load). In one set of trials, participants stepped from a low step (5 cm) and pain was induced by noxious electrical stimulation over the sacrum triggered from foot contact with a force plate or was anticipated. Changes in EMG amplitude and onset timing were compared between conditions. Hip muscle activation was earlier and larger when stepping from higher steps. Although ground reaction forces (one of the determinants of joint load) were unchanged before, during and after pain, trials with real or anticipated noxious stimulation were accompanied by muscle activity indistinguishable from that normally reserved for higher steps (EMG amplitude increased from 9 to 17 % of peak). These data support the notion that muscle activation for postural control is augmented when challenged by real/anticipated noxious stimulation. Muscle activation was earlier and greater than that required for the task and is likely to create unnecessary joint loading. This could have long-term consequences if maintained.

Altered Ca2+ signaling in skeletal muscle fibers of the R6/2 mouse, a model of Huntington’s disease

PubMed Central

Braubach, Peter; Orynbayev, Murat; Andronache, Zoita; Hering, Tanja; Landwehrmeyer, Georg Bernhard; Lindenberg, Katrin S.

2014-01-01

Huntington’s disease (HD) is caused by an expanded CAG trinucleotide repeat within the gene encoding the protein huntingtin. The resulting elongated glutamine (poly-Q) sequence of mutant huntingtin (mhtt) affects both central neurons and skeletal muscle. Recent reports suggest that ryanodine receptor–based Ca2+ signaling, which is crucial for skeletal muscle excitation–contraction coupling (ECC), is changed by mhtt in HD neurons. Consequently, we searched for alterations of ECC in muscle fibers of the R6/2 mouse, a mouse model of HD. We performed fluorometric recordings of action potentials (APs) and cellular Ca2+ transients on intact isolated toe muscle fibers (musculi interossei), and measured L-type Ca2+ inward currents on internally dialyzed fibers under voltage-clamp conditions. Both APs and AP-triggered Ca2+ transients showed slower kinetics in R6/2 fibers than in fibers from wild-type mice. Ca2+ removal from the myoplasm and Ca2+ release flux from the sarcoplasmic reticulum were characterized using a Ca2+ binding and transport model, which indicated a significant reduction in slow Ca2+ removal activity and Ca2+ release flux both after APs and under voltage-clamp conditions. In addition, the voltage-clamp experiments showed a highly significant decrease in L-type Ca2+ channel conductance. These results indicate profound changes of Ca2+ turnover in skeletal muscle of R6/2 mice and suggest that these changes may be associated with muscle pathology in HD. PMID:25348412

Weaning failure and respiratory muscle function: What has been done and what can be improved?

PubMed

Magalhães, Paulo A F; Camillo, Carlos A; Langer, Daniel; Andrade, Lívia B; Duarte, Maria do Carmo M B; Gosselink, Rik

2018-01-01

Respiratory muscle dysfunction, being a common cause of weaning failure, is strongly associated with prolonged mechanical ventilation (MV) and prolonged stay in intensive care units. Inspiratory muscle training (IMT) has been described as an important contributor to the treatment of respiratory muscle dysfunction in critically ill patients. Its effectiveness is however yet controversial. To discuss evidence for assessment of readiness and the effectiveness of interventions for liberation from MV, with special attention to the role of IMT. PubMed, LILACS, PEDro and Web of Science were searched for papers of assessment and treatment of patients who failed liberation from MV after at least one attempt published in English or Portuguese until June 2016. Weaning predictors are related to weaning success (86%-100% for sensitivity and 7%-69% for specificity) and work of breathing (73%-100% for sensitivity and 56%-100% for specificity). Spontaneous breathing trials (SBT), noninvasive MV and early mobilization have been reported to improve weaning outcomes. Two modalities of IMT were identified in five selected studies: 1) adjustment of ventilator trigger sensitivity 2) inspiratory threshold loading. Both IMT training modalities promoted significant increases in respiratory muscle strength. IMT with threshold loading showed positive effect on endurance compared to control. Methods to indentify respiratory muscle weakness in critically ill patients are feasible and described as indexes that show good accuracy. Individualized and supervised rehabilitation programs including IMT, SBT, noninvasive MV and early mobilization should be encouraged in patients with inspiratory muscle weakness. Copyright © 2017 Elsevier Ltd. All rights reserved.

Focal myositis: A review.

PubMed

Devic, P; Gallay, L; Streichenberger, N; Petiot, P

2016-11-01

Amongst the heterogeneous group of inflammatory myopathies, focal myositis stands as a rare and benign dysimmune disease. Although it can be associated with root and/or nerve lesions, traumatic muscle lesions and autoimmune diseases, its triggering factors remain poorly understood. Defined as an isolated inflammatory pseudotumour usually restricted to one skeletal muscle, clinical presentation of focal myositis is that of a rapidly growing solitary mass within a single muscle, usually in the lower limbs. Electromyography shows spontaneous activity associated with a myopathic pattern. MRI reveals a contrast enhanced enlarged muscle appearing hyper-intense on FAT-SAT T2 weighted images. Adjacent structures are spared and there are no calcifications. Serum creatine kinase (CK) levels are usually moderately augmented and biological markers of systemic inflammation are absent in most cases. Pathological histological features include marked variation in fibre size, inflammatory infiltrates mostly composed of T CD4+ lymphocytes and macrophages, degenerating/regenerating fibres and interstitial fibrosis. Differential diagnoses are numerous and include myositis of other origin with focal onset. Steroid treatment should be reserved for patients who present with major pain, nerve lesions, associated autoimmune disease, or elevated C reactive protein or CK. Copyright © 2016 Elsevier B.V. All rights reserved.

Influence of Lumbar Muscle Fatigue on Trunk Adaptations during Sudden External Perturbations

PubMed Central

Abboud, Jacques; Nougarou, François; Lardon, Arnaud; Dugas, Claude; Descarreaux, Martin

2016-01-01

Introduction: When the spine is subjected to perturbations, neuromuscular responses such as reflex muscle contractions contribute to the overall balance control and spinal stabilization mechanisms. These responses are influenced by muscle fatigue, which has been shown to trigger changes in muscle recruitment patterns. Neuromuscular adaptations, e.g., attenuation of reflex activation and/or postural oscillations following repeated unexpected external perturbations, have also been described. However, the characterization of these adaptations still remains unclear. Using high-density electromyography (EMG) may help understand how the nervous system chooses to deal with an unknown perturbation in different physiological and/or mechanical perturbation environments. Aim: To characterize trunk neuromuscular adaptations following repeated sudden external perturbations after a back muscle fatigue task using high-density EMG. Methods: Twenty-five healthy participants experienced a series of 15 sudden external perturbations before and after back muscle fatigue. Erector spinae muscle activity was recorded using high-density EMG. Trunk kinematics during perturbation trials were collected using a 3-D motion analysis system. A two-way repeated measure ANOVA was conducted to assess: (1) the adaptation effect across trials; (2) the fatigue effect; and (3) the interaction effect (fatigue × adaptation) for the baseline activity, the reflex latency, the reflex peak and trunk kinematic variables (flexion angle, velocity and time to peak velocity). Muscle activity spatial distribution before and following the fatigue task was also compared using t-tests for dependent samples. Results: An attenuation of muscle reflex peak was observed across perturbation trials before the fatigue task, but not after. The spatial distribution of muscle activity was significantly higher before the fatigue task compared to post-fatigue trials. Baseline activity showed a trend to higher values after muscle fatigue, as well as reduction through perturbation trials. Main effects of fatigue and adaptation were found for time to peak velocity. No adaptation nor fatigue effect were identified for reflex latency, flexion angle or trunk velocity. Conclusion: The results show that muscle fatigue leads to reduced spatial distribution of back muscle activity and suggest a limited ability to use across-trial redundancy to adapt EMG reflex peak and optimize spinal stabilization using retroactive control. PMID:27895569

Combined Electrocardiography- and Respiratory-Triggered CT of the Lung to Reduce Respiratory Misregistration Artifacts between Imaging Slabs in Free-Breathing Children: Initial Experience.

PubMed

Goo, Hyun Woo; Allmendinger, Thomas

2017-01-01

Cardiac and respiratory motion artifacts degrade the image quality of lung CT in free-breathing children. The aim of this study was to evaluate the effect of combined electrocardiography (ECG) and respiratory triggering on respiratory misregistration artifacts on lung CT in free-breathing children. In total, 15 children (median age 19 months, range 6 months-8 years; 7 boys), who underwent free-breathing ECG-triggered lung CT with and without respiratory-triggering were included. A pressure-sensing belt of a respiratory gating system was used to obtain the respiratory signal. The degree of respiratory misregistration artifacts between imaging slabs was graded on a 4-point scale (1, excellent image quality) on coronal and sagittal images and compared between ECG-triggered lung CT studies with and without respiratory triggering. A p value < 0.05 was considered significant. Lung CT with combined ECG and respiratory triggering showed significantly less respiratory misregistration artifacts than lung CT with ECG triggering only (1.1 ± 0.4 vs. 2.2 ± 1.0, p = 0.003). Additional respiratory-triggering reduces respiratory misregistration artifacts on ECG-triggered lung CT in free-breathing children.

Sites of Successful Ventricular Fibrillation Ablation in Bileaflet Mitral Valve Prolapse Syndrome.

PubMed

Syed, Faisal F; Ackerman, Michael J; McLeod, Christopher J; Kapa, Suraj; Mulpuru, Siva K; Sriram, Chenni S; Cannon, Bryan C; Asirvatham, Samuel J; Noseworthy, Peter A

2016-05-01

Although the vast majority of mitral valve prolapse (MVP) is benign, a small subset of patients, predominantly women, with bileaflet prolapse, complex ventricular ectopy (VE), and abnormal T waves comprise the recently described bileaflet MVP syndrome. We compared findings on electrophysiological study in bileaflet MVP syndrome patients with and without cardiac arrest to identify factors that may predispose to malignant ventricular arrhythmia. Fourteen consecutive bileaflet MVP syndrome patients (n=13 women; median [limits], age at index ablation, 33.8 [21.0-58.7] years; ejection fraction, 60% [45%-67%]; all ≤ moderate mitral regurgitation; n=6 with previous cardiac arrest and implantable cardioverter defibrillator shocks for ventricular fibrillation; and n=8 without implantable cardioverter defibrillator although with symptomatic complex VE) were included. The 2 groups had similar baseline echocardiographic and electrocardiographic characteristics. All patients had at least 1 left ventricular papillary or fascicular VE focus. Purkinje origin VE was identified as the ventricular fibrillation trigger in 6 of 6 cardiac arrest patients (4 from papillary muscle) and Purkinje origin of dominant VE was seen in 5 of 8 (3 from papillary muscle) nonarrest patients. Acute success was seen in 17 of 19 procedures, and a ventricular fibrillation storm occurred within 24 hours of ablation in a single patient. Repeat ablation for recurrent symptomatic arrhythmia was performed in 6 patients. At 478 (39-2099) days of follow-up, 2 cardiac arrest patients received appropriate shocks. Symptoms from VE were reduced in 12 of 14. Bileaflet MVP syndrome is characterized by fascicular and papillary muscle VE that triggers ventricular fibrillation. Ablation of clinically dominant VE foci improves symptoms and reduces appropriate implantable cardioverter defibrillator shocks. © 2016 American Heart Association, Inc.

Bilateral force transients in the upper limbs evoked by single-pulse microstimulation in the pontomedullary reticular formation.

PubMed

Hirschauer, Thomas J; Buford, John A

2015-04-01

Neurons in the pontomedullary reticular formation (PMRF) give rise to the reticulospinal tract. The motor output of the PMRF was investigated using stimulus-triggered averaging of electromyography (EMG) and force recordings in two monkeys (M. fascicularis). EMG was recorded from 12 pairs of upper limb muscles, and forces were detected using two isometric force-sensitive handles. Of 150 stimulation sites, 105 (70.0%) produced significant force responses, and 139 (92.5%) produced significant EMG responses. Based on the average flexor EMG onset latency of 8.3 ms and average force onset latency of 15.9 ms poststimulation, an electromechanical delay of ∼7.6 ms was calculated. The magnitude of force responses (∼10 mN) was correlated with the average change in EMG activity (P < 0.001). A multivariate linear regression analysis was used to estimate the contribution of each muscle to force generation, with flexors and extensors exhibiting antagonistic effects. A predominant force output pattern of ipsilateral flexion and contralateral extension was observed in response to PMRF stimulation, with 65.3% of significant ipsilateral force responses directed medially and posteriorly (P < 0.001) and 78.6% of contralateral responses directed laterally and anteriorly (P < 0.001). This novel approach permits direct measurement of force outputs evoked by central nervous system microstimulation. Despite the small magnitude of poststimulus EMG effects, low-intensity single-pulse microstimulation of the PMRF evoked detectable forces. The forces, showing the combined effect of all muscle activity in the arms, are consistent with reciprocal pattern of force outputs from the PMRF detectable with stimulus-triggered averaging of EMG. Copyright © 2015 the American Physiological Society.

Chinese Massage Combined with Herbal Ointment for Athletes with Nonspecific Low Back Pain: A Randomized Controlled Trial

PubMed Central

Kong, Ling Jun; Fang, Min; Zhan, Hong Sheng; Yuan, Wei An; Tao, Ji Ming; Qi, Gao Wei; Cheng, Ying Wu

2012-01-01

Non-specific low back pain (NLBP) is an increasing health problem for athletes. This randomized controlled trial was designed to investigate the effects of Chinese massage combined with herbal ointment for NLBP. 110 athletes with NLBP were randomly assigned to experimental group with Chinese massage combined with herbal ointment or control group with simple massage therapy. The primary outcome was pain by Chinese Short Form McGill Pain Questionnaire (C-SFMPQ). The secondary outcome was local muscle stiffness by Myotonometer. After 4 weeks, the experimental group experienced significant improvements in C-SFMPQ and in local muscle stiffness compared with control group (between-group difference in mean change from baseline, −1.24 points, P = 0.005 in sensory scores; −3.14 points, P < 0.001 in affective scores; −4.39 points, P < 0.001 in total scores; −0.64 points, P = 0.002 in VAS; −1.04 points, P = 0.005 in local muscle stiffness during relaxation state). The difference remained at one month followup, but it was only significant in affective scores (−2.83 points, P < 0.001) at three months followup. No adverse events were observed. These findings suggest that Chinese massage combined with herbal ointment may be a beneficial complementary and alternative therapy for athletes with NLBP. PMID:23258996

Automated muscle wrapping using finite element contact detection.

PubMed

Favre, Philippe; Gerber, Christian; Snedeker, Jess G

2010-07-20

Realistic muscle path representation is essential to musculoskeletal modeling of joint function. Algorithms predicting these muscle paths typically rely on a labor intensive predefinition of via points or underlying geometries to guide wrapping for given joint positions. While muscle wrapping using anatomically precise three-dimensional (3D) finite element (FE) models of bone and muscle has been achieved, computational expense and pre-processing associated with this approach exclude its use in applications such as subject-specific modeling. With the intention of combining advantageous features of both approaches, an intermediate technique relying on contact detection capabilities of commercial FE packages is presented. We applied the approach to the glenohumeral joint, and validated the method by comparison against existing experimental data. Individual muscles were modeled as a straight series of deformable beam elements and bones as anatomically precise 3D rigid bodies. Only the attachment locations and a default orientation of the undeformed muscle segment were pre-defined. The joint was then oriented in a static position of interest. The muscle segment free end was then moved along the shortest Euclidean path to its origin on the scapula, wrapping the muscle along bone surfaces by relying on software contact detection. After wrapping for a given position, the resulting moment arm was computed as the perpendicular distance from the line of action vector to the humeral head center of rotation. This approach reasonably predicted muscle length and moment arm for 27 muscle segments when compared to experimental measurements over a wide range of shoulder motion. Artificial via points or underlying contact geometries were avoided, contact detection and multiobject wrapping on the bone surfaces were automatic, and low computational cost permitted wrapping of individual muscles within seconds on a standard desktop PC. These advantages may be valuable for both general and subject-specific musculoskeletal modeling. 2010 Elsevier Ltd. All rights reserved.

Continuous Release of Tumor-Derived Factors Improves the Modeling of Cachexia in Muscle Cell Culture.

PubMed

Jackman, Robert W; Floro, Jess; Yoshimine, Rei; Zitin, Brian; Eiampikul, Maythita; El-Jack, Kahlid; Seto, Danielle N; Kandarian, Susan C

2017-01-01

Cachexia is strongly associated with a poor prognosis in cancer patients but the biological trigger is unknown and therefore no therapeutics exist. The loss of skeletal muscle is the most deleterious aspect of cachexia and it appears to depend on secretions from tumor cells. Models for studying wasting in cell culture consist of experiments where skeletal muscle cells are incubated with medium conditioned by tumor cells. This has led to candidates for cachectic factors but some of the features of cachexia in vivo are not yet well-modeled in cell culture experiments. Mouse myotube atrophy measured by myotube diameter in response to medium conditioned by mouse colon carcinoma cells (C26) is consistently less than what is seen in muscles of mice bearing C26 tumors with moderate to severe cachexia. One possible reason for this discrepancy is that in vivo the C26 tumor and skeletal muscle share a circulatory system exposing the muscle to tumor factors in a constant and increasing way. We have applied Transwell®-adapted cell culture conditions to more closely simulate conditions found in vivo where muscle is exposed to the ongoing kinetics of constant tumor secretion of active factors. C26 cells were incubated on a microporous membrane (a Transwell® insert) that constitutes the upper compartment of wells containing plated myotubes. In this model, myotubes are exposed to a constant supply of cancer cell secretions in the medium but without direct contact with the cancer cells, analogous to a shared circulation of muscle and cancer cells in tumor-bearing animals. The results for myotube diameter support the idea that the use of Transwell® inserts serves as a more physiological model of the muscle wasting associated with cancer cachexia than the bolus addition of cancer cell conditioned medium. The Transwell® model supports the notion that the dose and kinetics of cachectic factor delivery to muscle play a significant role in the extent of pathology.

AMPKα2 deficiency uncovers time dependency in the regulation of contraction-induced palmitate and glucose uptake in mouse muscle.

PubMed

Abbott, Marcia J; Bogachus, Lindsey D; Turcotte, Lorraine P

2011-07-01

AMP-activated protein kinase (AMPK) is a fuel sensor in skeletal muscle with multiple downstream signaling targets that may be triggered by increases in intracellular Ca(2+) concentration ([Ca(2+)]). The purpose of this study was to determine whether increases in intracellular [Ca(2+)] induced by caffeine act solely via AMPKα(2) and whether AMPKα(2) is essential to increase glucose uptake, fatty acid (FA) uptake, and FA oxidation in contracting skeletal muscle. Hindlimbs from wild-type (WT) or AMPKα(2) dominant-negative (DN) transgene mice were perfused during rest (n = 11), treatment with 3 mM caffeine (n = 10), or muscle contraction (n = 11). Time-dependent effects on glucose and FA uptake were uncovered throughout the 20-min muscle contraction perfusion period (P < 0.05). Glucose uptake rates did not increase in DN mice during muscle contraction until the last 5 min of the protocol (P < 0.05). FA uptake rates were elevated at the onset of muscle contraction and diminished by the end of the protocol in DN mice (P < 0.05). FA oxidation rates were abolished in the DN mice during muscle contraction (P < 0.05). The DN transgene had no effect on caffeine-induced FA uptake and oxidation (P > 0.05). Glucose uptake rates were blunted in caffeine-treated DN mice (P < 0.05). The DN transgene resulted in a greater use of intramuscular triglycerides as a fuel source during muscle contraction. The DN transgene did not alter caffeine- or contraction-mediated changes in the phosphorylation of Ca(2+)/calmodulin-dependent protein kinase I or ERK1/2 (P > 0.05). These data suggest that AMPKα(2) is involved in the regulation of substrate uptake in a time-dependent manner in contracting muscle but is not necessary for regulation of FA uptake and oxidation during caffeine treatment.

Upregulation of Immunoproteasome Subunits in Myositis Indicates Active Inflammation with Involvement of Antigen Presenting Cells, CD8 T-Cells and IFNγ

PubMed Central

Ghannam, Khetam; Martinez-Gamboa, Lorena; Spengler, Lydia; Krause, Sabine; Smiljanovic, Biljana; Bonin, Marc; Bhattarai, Salyan; Grützkau, Andreas; Burmester, Gerd-R.

2014-01-01

Objective In idiopathic inflammatory myopathies (IIM) infiltration of immune cells into muscle and upregulation of MHC-I expression implies increased antigen presentation and involvement of the proteasome system. To decipher the role of immunoproteasomes in myositis, we investigated individual cell types and muscle tissues and focused on possible immune triggers. Methods Expression of constitutive (PSMB5, -6, -7) and corresponding immunoproteasomal subunits (PSMB8, -9, -10) was analyzed by real-time RT-PCR in muscle biopsies and sorted peripheral blood cells of patients with IIM, non-inflammatory myopathies (NIM) and healthy donors (HD). Protein analysis in muscle biopsies was performed by western blot. Affymetrix HG-U133 platform derived transcriptome data from biopsies of different muscle diseases and from immune cell types as well as monocyte stimulation experiments were used for validation, coregulation and coexpression analyses. Results Real-time RT-PCR revealed significantly increased expression of immunoproteasomal subunits (PSMB8/-9/-10) in DC, monocytes and CD8+ T-cells in IIM. In muscle biopsies, the immunosubunits were elevated in IIM compared to NIM and exceeded levels of matched blood samples. Proteins of PSMB8 and -9 were found only in IIM but not NIM muscle biopsies. Reanalysis of 78 myositis and 20 healthy muscle transcriptomes confirmed these results and revealed involvement of the antigen processing and presentation pathway. Comparison with reference profiles of sorted immune cells and healthy muscle confirmed upregulation of PSMB8 and -9 in myositis biopsies beyond infiltration related changes. This upregulation correlated highest with STAT1, IRF1 and IFNγ expression. Elevation of T-cell specific transcripts in active IIM muscles was accompanied by increased expression of DC and monocyte marker genes and thus reflects the cell type specific involvement observed in peripheral blood. Conclusions Immunoproteasomes seem to indicate IIM activity and suggest that dominant involvement of antigen processing and presentation may qualify these diseases exemplarily for the evolving therapeutic concepts of immunoproteasome specific inhibition. PMID:25098831

Upregulation of immunoproteasome subunits in myositis indicates active inflammation with involvement of antigen presenting cells, CD8 T-cells and IFNΓ.

PubMed

Ghannam, Khetam; Martinez-Gamboa, Lorena; Spengler, Lydia; Krause, Sabine; Smiljanovic, Biljana; Bonin, Marc; Bhattarai, Salyan; Grützkau, Andreas; Burmester, Gerd-R; Häupl, Thomas; Feist, Eugen

2014-01-01

In idiopathic inflammatory myopathies (IIM) infiltration of immune cells into muscle and upregulation of MHC-I expression implies increased antigen presentation and involvement of the proteasome system. To decipher the role of immunoproteasomes in myositis, we investigated individual cell types and muscle tissues and focused on possible immune triggers. Expression of constitutive (PSMB5, -6, -7) and corresponding immunoproteasomal subunits (PSMB8, -9, -10) was analyzed by real-time RT-PCR in muscle biopsies and sorted peripheral blood cells of patients with IIM, non-inflammatory myopathies (NIM) and healthy donors (HD). Protein analysis in muscle biopsies was performed by western blot. Affymetrix HG-U133 platform derived transcriptome data from biopsies of different muscle diseases and from immune cell types as well as monocyte stimulation experiments were used for validation, coregulation and coexpression analyses. Real-time RT-PCR revealed significantly increased expression of immunoproteasomal subunits (PSMB8/-9/-10) in DC, monocytes and CD8+ T-cells in IIM. In muscle biopsies, the immunosubunits were elevated in IIM compared to NIM and exceeded levels of matched blood samples. Proteins of PSMB8 and -9 were found only in IIM but not NIM muscle biopsies. Reanalysis of 78 myositis and 20 healthy muscle transcriptomes confirmed these results and revealed involvement of the antigen processing and presentation pathway. Comparison with reference profiles of sorted immune cells and healthy muscle confirmed upregulation of PSMB8 and -9 in myositis biopsies beyond infiltration related changes. This upregulation correlated highest with STAT1, IRF1 and IFNγ expression. Elevation of T-cell specific transcripts in active IIM muscles was accompanied by increased expression of DC and monocyte marker genes and thus reflects the cell type specific involvement observed in peripheral blood. Immunoproteasomes seem to indicate IIM activity and suggest that dominant involvement of antigen processing and presentation may qualify these diseases exemplarily for the evolving therapeutic concepts of immunoproteasome specific inhibition.

Opposite effects of statins on mitochondria of cardiac and skeletal muscles: a ‘mitohormesis’ mechanism involving reactive oxygen species and PGC-1

PubMed Central

Bouitbir, Jamal; Charles, Anne-Laure; Echaniz-Laguna, Andoni; Kindo, Michel; Daussin, Frédéric; Auwerx, Johan; Piquard, François; Geny, Bernard; Zoll, Joffrey

2012-01-01

Aims Statins protect against cardiovascular-related mortality but induce skeletal muscle toxicity. To investigate mechanisms of statins, we tested the hypothesis that statins optimized cardiac mitochondrial function but impaired vulnerable skeletal muscle by inducing different level of reactive oxygen species (ROS). Methods and results In atrium of patients treated with statins, ROS production was decreased and oxidative capacities were enhanced together with an extensive augmentation of mRNAs expression of peroxisome proliferator-activated receptor gamma co-activator (PGC-1) family. However, in deltoid biopsies from patients with statin-induced muscular myopathy, oxidative capacities were decreased together with ROS increase and a collapse of PGC-1 mRNA expression. Several animal and cell culture experiments were conducted and showed by using ROS scavengers that ROS production was the triggering factor responsible of atorvastatin-induced activation of mitochondrial biogenesis pathway and improvement of antioxidant capacities in heart. Conversely, in skeletal muscle, the large augmentation of ROS production following treatment induced mitochondrial impairments, and reduced mitochondrial biogenesis mechanisms. Quercetin, an antioxidant molecule, was able to counteract skeletal muscle deleterious effects of atorvastatin in rat. Conclusion Our findings identify statins as a new activating factor of cardiac mitochondrial biogenesis and antioxidant capacities, and suggest the importance of ROS/PGC-1 signalling pathway as a key element in regulation of mitochondrial function in cardiac as well as skeletal muscles. PMID:21775390

Gender variability in electromyographic activity, in vivo behaviour of the human gastrocnemius and mechanical capacity during the take-off phase of a countermovement jump.

PubMed

Rubio-Arias, Jacobo Ángel; Ramos-Campo, Domingo Jesús; Peña Amaro, José; Esteban, Paula; Mendizábal, Susana; Jiménez, José Fernando

2017-11-01

The purpose of this study was to analyse gender differences in neuromuscular behaviour of the gastrocnemius and vastus lateralis during the take-off phase of a countermovement jump (CMJ), using direct measures (ground reaction forces, muscle activity and dynamic ultrasound). Sixty-four young adults (aged 18-25 years) participated voluntarily in this study, 35 men and 29 women. The firing of the trigger allowed obtainment of data collection vertical ground reaction forces (GRF), surface electromyography activity (sEMG) and dynamic ultrasound gastrocnemius of both legs. Statistically significant gender differences were observed in the jump performance, which appear to be based on differences in muscle architecture and the electrical activation of the gastrocnemius muscles and vastus lateralis. So while men developed greater peak power, velocity take-offs and jump heights, jump kinetics compared to women, women also required a higher electrical activity to develop lower power values. Additionally, the men had higher values pennation angles and muscle thickness than women. Men show higher performance of the jump test than women, due to significant statistical differences in the values of muscle architecture (pennation angle and thickness muscle), lower Neural Efficiency Index and a higher amount of sEMG activity per second during the take-off phase of a CMJ. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Patterns of gene expression in atrophying skeletal muscles: response to food deprivation

NASA Technical Reports Server (NTRS)

Jagoe, R. Thomas; Lecker, Stewart H.; Gomes, Marcelo; Goldberg, Alfred L.

2002-01-01

During fasting and many systemic diseases, muscle undergoes rapid loss of protein and functional capacity. To define the transcriptional changes triggering muscle atrophy and energy conservation in fasting, we used cDNA microarrays to compare mRNAs from muscles of control and food-deprived mice. Expression of >94% of genes did not change, but interesting patterns emerged among genes that were differentially expressed: 1) mRNAs encoding polyubiquitin, ubiquitin extension proteins, and many (but not all) proteasome subunits increased, which presumably contributes to accelerated protein breakdown; 2) a dramatic increase in mRNA for the ubiquitin ligase, atrogin-1, but not most E3s; 3) a significant suppression of mRNA for myosin binding protein H (but not other myofibrillar proteins) and IGF binding protein 5, which may favor cell protein loss; 4) decreases in mRNAs for several glycolytic enzymes and phosphorylase kinase subunits, and dramatic increases in mRNAs for pyruvate dehydrogenase kinase 4 and glutamine synthase, which should promote glucose sparing and gluconeogenesis. During fasting, metallothionein mRNA increased dramatically, mRNAs for extracellular matrix components fell, and mRNAs that may favor cap-independent mRNA translation rose. Significant changes occurred in mRNAs for many growth-related proteins and transcriptional regulators. These transcriptional changes indicate a complex adaptive program that should favor protein degradation and suppress glucose oxidation in muscle. Similar analysis of muscles atrophying for other causes is allowing us to identify a set of atrophy-specific changes in gene expression.

Length adaptation of airway smooth muscle.

PubMed

Bossé, Ynuk; Sobieszek, Apolinary; Paré, Peter D; Seow, Chun Y

2008-01-01

Many types of smooth muscle, including airway smooth muscle (ASM), are capable of generating maximal force over a large length range due to length adaptation, which is a relatively rapid process in which smooth muscle regains contractility after experiencing a force decrease induced by length fluctuation. Although the underlying mechanism is unclear, it is believed that structural malleability of smooth muscle cells is essential for the adaptation to occur. The process is triggered by strain on the cell cytoskeleton that results in a series of yet undefined biochemical and biophysical events leading to restructuring of the cytoskeleton and contractile apparatus and consequently optimization of the overlap between the myosin and actin filaments. Although length adaptability is an intrinsic property of smooth muscle, maladaptation of ASM could result in excessive constriction of the airways and the inability of deep inspirations to dilate them. In this article, we describe the phenomenon of length adaptation in ASM and some possible underlying mechanisms that involve the myosin filament assembly and disassembly. We discuss a possible role of maladaptation of ASM in the pathogenesis of asthma. We believe that length adaptation in ASM is mediated by specific proteins and their posttranslational regulations involving covalent modifications, such as phosphorylation. The discovery of these molecules and the processes that regulate their activity will greatly enhance our understanding of the basic mechanisms of ASM contraction and will suggest molecular targets to alleviate asthma exacerbation related to excessive constriction of the airways.

Phosphatidylinositol 3-kinase inhibition restores Ca2+ release defects and prolongs survival in myotubularin-deficient mice

PubMed Central

Kutchukian, Candice; Lo Scrudato, Mirella; Tourneur, Yves; Poulard, Karine; Vignaud, Alban; Berthier, Christine; Allard, Bruno; Lawlor, Michael W.; Buj-Bello, Ana; Jacquemond, Vincent

2016-01-01

Mutations in the gene encoding the phosphoinositide 3-phosphatase myotubularin (MTM1) are responsible for a pediatric disease of skeletal muscle named myotubular myopathy (XLMTM). Muscle fibers from MTM1-deficient mice present defects in excitation–contraction (EC) coupling likely responsible for the disease-associated fatal muscle weakness. However, the mechanism leading to EC coupling failure remains unclear. During normal skeletal muscle EC coupling, transverse (t) tubule depolarization triggers sarcoplasmic reticulum (SR) Ca2+ release through ryanodine receptor channels gated by conformational coupling with the t-tubule voltage-sensing dihydropyridine receptors. We report that MTM1 deficiency is associated with a 60% depression of global SR Ca2+ release over the full range of voltage sensitivity of EC coupling. SR Ca2+ release in the diseased fibers is also slower than in normal fibers, or delayed following voltage activation, consistent with the contribution of Ca2+-gated ryanodine receptors to EC coupling. In addition, we found that SR Ca2+ release is spatially heterogeneous within myotubularin-deficient muscle fibers, with focally defective areas recapitulating the global alterations. Importantly, we found that pharmacological inhibition of phosphatidylinositol 3-kinase (PtdIns 3-kinase) activity rescues the Ca2+ release defects in isolated muscle fibers and increases the lifespan and mobility of XLMTM mice, providing proof of concept for the use of PtdIns 3-kinase inhibitors in myotubular myopathy and suggesting that unbalanced PtdIns 3-kinase activity plays a critical role in the pathological process. PMID:27911767

Dynamic Pointing Triggers Shifts of Visual Attention in Young Infants

ERIC Educational Resources Information Center

Rohlfing, Katharina J.; Longo, Matthew R.; Bertenthal, Bennett I.

2012-01-01

Pointing, like eye gaze, is a deictic gesture that can be used to orient the attention of another person towards an object or an event. Previous research suggests that infants first begin to follow a pointing gesture between 10 and 13 months of age. We investigated whether sensitivity to pointing could be seen at younger ages employing a technique…

Thoracic dysfunction in whiplash associated disorders: A systematic review

PubMed Central

Smith, Richard; Tyros, Isaak; Falla, Deborah; Rushton, Alison

2018-01-01

Background Research investigating Whiplash Associated Disorder (WAD) has largely focused on the cervical spine yet symptoms can be widespread. Thoracic spine pain prevalence is reported ~66%; perhaps unsurprising given the forceful stretch/eccentric loading of posterior structures of the spine, and the thoracic spine’s contribution to neck mobility/function. Approximately 50% WAD patients develop chronic pain and disability resulting in high levels of societal and healthcare costs. It is time to look beyond the cervical spine to fully understand anatomical dysfunction in WAD and provide new directions for clinical practice and research. Purpose To evaluate the scope and nature of dysfunction in the thoracic region in patients with WAD. Methods A systematic review and data synthesis was conducted according to a pre-defined, registered (PROSPERO, CRD42015026983) and published protocol. All forms of observational study were included. A sensitive topic-based search strategy was designed from inception to 1/06/16. Databases, grey literature and registers were searched using a study population terms and key words derived from scoping search. Two reviewers independently searched information sources, assessed studies for inclusion, extracted data and assessed risk of bias. A third reviewer checked for consistency and clarity. Extracted data included summary data: sample size and characteristics, outcomes, and timescales to reflect disorder state. Risk of bias was assessed using the Newcastle-Ottawa Scale. Data were tabulated to allow enabling a semi-qualitative comparison and grouped by outcome across studies. Strength of the overall body of evidence was assessed using a modified GRADE. Results Thirty eight studies (n>50,000) which were conducted across a range of countries were included. Few authors responded to requests for further data (5 of 9 contacted). Results were reported in the context of overall quality and were presented for measures of pain or dysfunction and presented, where possible, according to WAD severity and time point post injury. Key findings include: 1) high prevalence of thoracic pain (>60%); higher for those with more severe presentations and in the acute stage, 2) low prevalence of chest pain (<22%), 3) evidence of thoracic outlet syndrome, with some association to and involvement of the brachial plexus, 4) muscle dysfunction in the form of heightened activity of the sternocleidomastoid or delayed onset of action of the serratus anterior, 5) high prevalence of myofascial pain and trigger points in the scalene muscles, sternocleidomastoid and mid/lower fibres of trapezius muscle (48–65%), and 6) inconclusive evidence of altered thoracic posture or mobility. Conclusions Considerable evidence supports thoracic pain and dysfunction in patients with WAD, involving primarily nerves and muscles. Notwithstanding the low/very low level of evidence from this review, our findings do support a more extensive clinical evaluation of patients presenting with WAD. Additional high quality research is required to further characterise dysfunction across other structures in the thoracic region, including but not limited to the thoracic spine (mobility and posture) and thoracic muscles (stiffness, activation patterns). In turn this may inform the design of clinical trials targeting such dysfunction. PMID:29570722

Adding motor control training to muscle strengthening did not substantially improve the effects on clinical or kinematic outcomes in women with patellofemoral pain: A randomised controlled trial.

PubMed

Rabelo, Nayra Deise Dos Anjos; Costa, Leonardo Oliveira Pena; Lima, Bruna Maria de; Dos Reis, Amir Curcio; Bley, André Serra; Fukuda, Thiago Yukio; Lucareli, Paulo Roberto Garcia

2017-10-01

Randomized controlled trial. Patients with Patellofemoral pain (PFP) usually present muscular weakness, pain and impaired motor control. Muscle strengthening is an effective treatment strategy for PFP, but the additional benefits of movement control training remain unknown. Therefore, the aim of this study was to compare the effects of movement control training associated with muscle strengthening, with a conventional program of strengthening alone in women with PFP. Thirty-four women were randomly assigned to two groups. The Strengthening group (S group) performed 12 sessions to strengthen the knee and hip muscles. The Movement Control & Strengthening group (MC&S group) performed the same exercises and movement control training of the trunk and lower limbs. Effects of the treatment (i.e., between-group differences) were calculated using linear mixed models. Primary outcomes were function and pain intensity after completion of the treatment protocol. Secondary outcomes were; muscle strength and kinematic outcomes during the step down task after 4 weeks of treatment; and function and pain intensity 3 and 6 months after randomization. The MC&S group did not present significantly better function (MD -2.5 points, 95% CI;-10.7-5.5) or pain (MD -0.3 points, 95% CI;-1.7-1.0) at 4 weeks. There was a small difference in favour of the MC&S group for AKPS scores at 3 months (MD -8.5 points; 95% CI;-16.8 to -0.3). No significant between-group differences were observed for the other outcomes. Movement control training was no more effective than the isolated strengthening protocol, in terms of pain, function, muscle strength, or kinematics. Copyright © 2017 Elsevier B.V. All rights reserved.

Reduced Short- and Long-Latency Afferent Inhibition Following Acute Muscle Pain: A Potential Role in the Recovery of Motor Output.

PubMed

Burns, Emma; Chipchase, Lucinda Sian; Schabrun, Siobhan May

2016-02-13

. Corticomotor output is reduced in response to acute muscle pain, yet the mechanisms that underpin this effect remain unclear. Here the authors investigate the effect of acute muscle pain on short-latency afferent inhibition, long-latency afferent inhibition, and long-interval intra-cortical inhibition to determine whether these mechanisms could plausibly contribute to reduced motor output in pain. . Observational same subject pre-post test design. . Neurophysiology research laboratory. . Healthy, right-handed human volunteers (n = 22, 9 male; mean age ± standard deviation, 22.6 ± 7.8 years). . Transcranial magnetic stimulation was used to assess corticomotor output, short-latency afferent inhibition, long-latency afferent inhibition, and long-interval intra-cortical inhibition before, during, immediately after, and 15 minutes after hypertonic saline infusion into right first dorsal interosseous muscle. Pain intensity and quality were recorded using an 11-point numerical rating scale and the McGill Pain Questionnaire. . Compared with baseline, corticomotor output was reduced at all time points (p = 0.001). Short-latency afferent inhibition was reduced immediately after (p = 0.039), and long-latency afferent inhibition 15 minutes after (p = 0.035), the resolution of pain. Long-interval intra-cortical inhibition was unchanged at any time point (p = 0.36). . These findings suggest short- and long-latency afferent inhibition, mechanisms thought to reflect the integration of sensory information with motor output at the cortex, are reduced following acute muscle pain. Although the functional relevance is unclear, the authors hypothesize a reduction in these mechanisms may contribute to the restoration of normal motor output after an episode of acute muscle pain. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Problem-Based Assignments as a Trigger for Developing Ethical and Reflective Competencies

ERIC Educational Resources Information Center

Euler, Dieter; Kühner, Patrizia

2017-01-01

The following research question serves as the starting point of this research and development project: How, in the context of a didactic design, can problem-based assignments trigger learning activities for the development of ethical and reflective competencies in students in economics courses? This paper focuses on the design of problem-based…

Anatomic and isometric points on femoral attachment site of popliteus muscle-tendon complex for the posterolateral corner reconstruction.

PubMed

Yang, Jae-Hyuk; Lim, Hong Chul; Bae, Ji Hoon; Fernandez, Harry; Bae, Tae Soo; Wang, Joon Ho

2011-10-01

Descriptive laboratory study. The femoral anatomic insertion site and the optimal isometric point of popliteus tendon for posterolateral reconstruction are not well known. Purpose of this study was to determine the relative relationship between the femoral anatomic insertion and isometric point of popliteus muscle-tendon complex with the lateral epicondyle of femur. Thirty unpaired cadaveric knees were dissected to determine the anatomic femoral insertion of the popliteus tendon. The distance and the angle from the lateral epicondyle of femur to the center of the anatomic insertion of the popliteus tendon were measured using digital caliper and goniometer. Eight unpaired fresh cadaveric knees were examined to determine the optimal isometric point of femoral insertion of popliteus tendon using computer-controlled motion capture analysis system (Motion Analysis, CA, USA). Distances from targeted tibial tunnel for popliteus tendon reconstruction to the 35 points gained on the lateral surface of femur were recorded at 0, 30, 60, 90, and 120° knee flexion. A point with the least excursion (<2.0 mm) was determined as the isometric point. The center of anatomic insertion points and the optimal isometric point for the main fibers of popliteus tendon were found to be posterior and distal to the lateral epicondyle of femur. The distance from the lateral epicondyle of femur to the center of anatomic femoral insertion of popliteus tendon was 11.3 ± 1.2 mm (mean ± SD). The angle between long axis of femur and the line from lateral epicondyle of femur to anatomic femoral insertion of popliteus tendon was 31.4 ± 5.3°. The isometric points for the femoral insertion of popliteus muscle-tendon complex were situated posterior and distal to the lateral epicondyle in all 8 knees. The distance between the least excursion point and the lateral epicondyle was calculated as 10.4 ± 1.7 mm. The angle between the long axis of femur and the line from lateral epicondyle of femur to optimum isometric point of popliteus tendon was calculated as 41.3 ± 14.9°. The optimal isometric point for the femoral insertion of popliteus muscle-tendon complex is situated posterior and distal to the lateral epicondyle of femur. Femoral tunnel for "posterolateral corner sling procedure" should be placed at this point to achieve least amount of graft excursion during knee motion.

[Clinical observation on therapeutic effect of cupping combined with acupuncture stimulation at trigger points for lumbar myofascial pain syndrome].

PubMed

Zhao, Hong

2014-08-01

To observe the clinical effect of cupping combined with acupuncture stimulation of trigger points on lumbar myofascial pain syndrome (MPS). Sixty MPS patients were randomly divided into acupuncture + TDP group (n = 30), and cupping + acupuncture group (n = 30). Patients in the acupuncture + TDP group were treated by acupuncture stimulation of trigger points and local TDP irradiation, and patients of the cupping + acupuncture group treated by intensive cupping applied to the myofascial band and acupuncture stimulation of the locus according to the position of muscular tension band. The therapeutic effects were assessed according to the score of the McGill pain questionnaire composing of pain rating index (PRI), visual analogue scale (VAS) and present pain intensity (PPI) before, immediately and 1 month after the treatment. After the treatment, the total effective rates of the acupuncture+ TDP and cupping + acupuncture groups were 83.3% (25/30) and 96.6% (29/30), respectively, without significant difference between the two groups (P > 0.05). One month's follow-up showed that the total effective rates of the acupuncture + TDP and cupping + acupuncture groups were 40.0% and 90.0% respectively, and the latter group was significantly better than the acupuncture + TDP group in the therapeutic effect (P < 0.05). The scores of PRI, VAS, PPI after the treatment were markedly decreased in both groups (P < 0.05). One month later, the scores of PRI, VAS and PPI in the cupping + acupuncture group were obviously lower than those of the acupuncture group (P < 0.05). Both acupuncture stimulation of trigger points plus TDP and cupping plus acupuncture can effectively relieve pain in MPS patients, while the therapeutic effect of cupping plus acupuncture treatment lasts longer analgesic effect.