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Sample records for biceps femoris muscles

  1. Accuracy assessment of CKC high-density surface EMG decomposition in biceps femoris muscle

    NASA Astrophysics Data System (ADS)

    Marateb, H. R.; McGill, K. C.; Holobar, A.; Lateva, Z. C.; Mansourian, M.; Merletti, R.

    2011-10-01

    The aim of this study was to assess the accuracy of the convolution kernel compensation (CKC) method in decomposing high-density surface EMG (HDsEMG) signals from the pennate biceps femoris long-head muscle. Although the CKC method has already been thoroughly assessed in parallel-fibered muscles, there are several factors that could hinder its performance in pennate muscles. Namely, HDsEMG signals from pennate and parallel-fibered muscles differ considerably in terms of the number of detectable motor units (MUs) and the spatial distribution of the motor-unit action potentials (MUAPs). In this study, monopolar surface EMG signals were recorded from five normal subjects during low-force voluntary isometric contractions using a 92-channel electrode grid with 8 mm inter-electrode distances. Intramuscular EMG (iEMG) signals were recorded concurrently using monopolar needles. The HDsEMG and iEMG signals were independently decomposed into MUAP trains, and the iEMG results were verified using a rigorous a posteriori statistical analysis. HDsEMG decomposition identified from 2 to 30 MUAP trains per contraction. 3 ± 2 of these trains were also reliably detected by iEMG decomposition. The measured CKC decomposition accuracy of these common trains over a selected 10 s interval was 91.5 ± 5.8%. The other trains were not assessed. The significant factors that affected CKC decomposition accuracy were the number of HDsEMG channels that were free of technical artifact and the distinguishability of the MUAPs in the HDsEMG signal (P < 0.05). These results show that the CKC method reliably identifies at least a subset of MUAP trains in HDsEMG signals from low force contractions in pennate muscles.

  2. Short-latency crossed responses in the human biceps femoris muscle

    PubMed Central

    Stevenson, Andrew J T; Kamavuako, Ernest N; Geertsen, Svend S; Farina, Dario; Mrachacz-Kersting, Natalie

    2015-01-01

    Interlimb reflexes contribute to the central neural co-ordination between different limbs in both humans and animals. Although commissural interneurons have only been directly identified in animals, spinally-mediated interlimb reflexes have been discovered in a number of human lower limb muscles, indicating their existence in humans. The present study aimed to investigate whether short-latency crossed-spinal reflexes are present in the contralateral biceps femoris (cBF) muscle following ipsilateral knee (iKnee) joint rotations during a sitting task, where participants maintained a slight pre-contraction in the cBF. Following iKnee extension joint rotations, an inhibitory reflex was observed in the surface electromyographic (EMG) activity of the cBF, whereas a facilitatory reflex was observed in the cBF following iKnee flexion joint rotations. The onset latency of both cBF reflexes was 44 ms, which is too fast for a transcortical pathway to contribute. The cBF inhibitory and facilitatory reflexes followed the automatic gain control principle, with the size of the response increasing as the level of background pre-contraction in the cBF muscle increased. In addition to the surface EMG, both short-latency inhibitory and facilitatory cBF reflexes were recorded directly at the motor unit level by i.m. EMG, and the same population of cBF motor units that were inhibited following iKnee extension joint rotations were facilitated following iKnee flexion joint rotations. Therefore, parallel interneuronal pathways (probably involving commissural interneurons) from ipsilateral afferents to common motoneurons in the contralateral leg can probably explain the perturbation direction-dependent reversal in the sign of the short-latency cBF reflex. PMID:25970767

  3. Quality properties and adsorption behavior of freeze-dried beef meat from the Biceps femoris and Semimembranosus muscles.

    PubMed

    Aykın, Elif; Erbaş, Mustafa

    2016-11-01

    The aim of this research was to determine the quality properties and adsorption behavior of freeze-dried beef meat from the Biceps femoris and Semimembranosus muscles. Most quality properties of both muscles were similar apart from total fat content. Freeze-dried meat pieces were kept in ten different equilibrium levels of relative humidity (2.0-97.3%) at 5, 15, 25 and 30°C. The experimental data were evaluated using BET (Brunauer-Emmett-Teller) and GAB (Guggenheim, Anderson and deBoer) models. The equilibrium moisture contents of freeze-dried Biceps femoris were lower than those of Semimembranosus at all water activities and temperature. The constants m0 and C of BET and GAB equations were determined to be between 6.27 and 8.07g/100g dry matter and 9.32-13.73, respectively. Constant k was about 0.90 at all temperatures, and the GAB equation exhibited a better fit to the experimental data of both muscles as a result of all %E values being approximately equal to 10%.

  4. Musculotendon variability influences tissue strains experienced by the biceps femoris long head muscle during high-speed running.

    PubMed

    Fiorentino, Niccolo M; Blemker, Silvia S

    2014-10-17

    The hamstring muscles frequently suffer injury during high-speed running, though the factors that make an individual more susceptible to injury remain poorly understood. The goals of this study were to measure the musculotendon dimensions of the biceps femoris long head (BFlh) muscle, the hamstring muscle injured most often, and to use computational models to assess the influence of variability in the BFlh's dimensions on internal tissue strains during high-speed running. High-resolution magnetic resonance (MR) images were acquired over the thigh in 12 collegiate athletes, and musculotendon dimensions were measured in the proximal free tendon/aponeurosis, muscle and distal free tendon/aponeurosis. Finite element meshes were generated based on the average, standard deviation and range of BFlh dimensions. Simulation boundary conditions were defined to match muscle activation and musculotendon length change in the BFlh during high-speed running. Muscle and connective tissue dimensions were found to vary between subjects, with a coefficient of variation (CV) of 17±6% across all dimensions. For all simulations peak local strain was highest along the proximal myotendinous junction, which is where injury typically occurs. Model variations showed that peak local tissue strain increased as the proximal aponeurosis width narrowed and the muscle width widened. The aponeurosis width and muscle width variation models showed that the relative dimensions of these structures influence internal muscle tissue strains. The results of this study indicate that a musculotendon unit's architecture influences its strain injury susceptibility during high-speed running.

  5. The physical and biochemical changes in springbok (Antidorcas marsupialis) Longissimus thoracis et lumborum and Biceps femoris muscle during ageing.

    PubMed

    North, M K; Frylinck, L; Hoffman, L C

    2015-12-01

    This study aimed to determine the optimum ageing period for vacuum-packed springbok (Antidorcas marsupialis) Longissimus thoracis et lumborum (LTL) and Biceps femoris (BF) muscle stored at 5.4 ± 1.0°C. Portions of muscle from seven male and six female springbok were aged 1, 2, 5, 8, 14 or 21 days. The Warner Bratzler shear force declined most during the first five days post-mortem (PM), while purge and cooking losses increased significantly with ageing. Calpains I and II and calpastatin activity declined significantly up to five days PM, suggesting that they may be responsible for tenderization. Cathepsins B, BL and H activity increased significantly during ageing. The BF muscle had significantly higher pH, lower purge loss, higher cooking loss, higher WBSF and higher calpain and calpastatin activity than the LTL. No significant differences between the genders or muscles were found for the collagen content or collagen solubility. Springbok LTL and BF muscles should not be aged for longer than five days.

  6. Neuromuscular efficiency of the vastus lateralis and biceps femoris muscles in individuals with anterior cruciate ligament injuries☆

    PubMed Central

    Aragão, Fernando Amâncio; Schäfer, Gabriel Santo; de Albuquerque, Carlos Eduardo; Vituri, Rogério Fonseca; de Azevedo, Fábio Mícolis; Bertolini, Gladson Ricardo Flor

    2015-01-01

    Objective To analyze strength and integrated electromyography (IEMG) data in order to determine the neuromuscular efficiency (NME) of the vastus lateralis (VL) and biceps femoris (BF) muscles in patients with anterior cruciate ligament (ACL) injuries, during the preoperative and postoperative periods; and to compare the injured limb at these two times, using the non-operated limb as a control. Methods EMG data and BF and VL strength data were collected during three maximum isometric contractions in knee flexion and extension movements. The assessment protocol was applied before the operation and two months after the operation, and the NME of the BF and VL muscles was obtained. Results There was no difference in the NME of the VL muscle from before to after the operation. On the other hand, the NME of the BF in the non-operated limb was found to have increased, two months after the surgery. Conclusions The NME provides a good estimate of muscle function because it is directly related to muscle strength and capacity for activation. However, the results indicated that two months after the ACL reconstruction procedure, at the time when loading in the open kinetic chain within rehabilitation protocols is usually started, the neuromuscular efficiency of the VL and BF had still not been reestablished. PMID:26229914

  7. The changes in springbok (Antidorcas marsupialis) Longissimus thoracis et lumborum and Biceps femoris muscles during the rigour period.

    PubMed

    North, M K; Frylinck, L; Hoffman, L C

    2016-02-01

    This study describes the changes taking place during rigour in springbok (Antidorcas marsupialis) Longissimus thoracis et lumborum (LTL) and Biceps femoris (BF) muscles. Samples from six male and six female springbok were snap-frozen at 2, 3, 5, 8, 12, 18, 24 and 30h post-mortem (PM) and the pH, calpains I, II and calpastatin activities and cathepsins B, BL and H activities were determined. The temperature was also recorded. Significant third-order interactions were found for the pH and temperature, with the female LTL cooling more rapidly and acidifying slower than the other samples. Female muscles were at risk of developing cold-shortening and all the samples cooled more rapidly than recommended for cattle or sheep. Cathepsin BL activity increased PM, likely due to the degradation of the lysosomes. Calpains I, II and calpastatin activity declined during rigour, indicating that the calpains were activated early PM. Gender and muscle had a significant effect on calpain and cathepsin activity.

  8. Proteome Changes in biceps femoris Muscle of Iranian
One-Humped Camel and Their Effect on Meat Quality Traits

    PubMed Central

    Varidi, Mohammad-Javad; Varidi, Mehdi

    2016-01-01

    Summary In this study physicochemical and quality traits of biceps femoris and longissimus thoracis muscles of male and female Iranian one-humped camel were determined during 14 days of refrigeration storage. Analysis of variance of the results showed that only shear force and temperature were affected by the gender (p<0.05). Anatomical location of the muscle influenced the meat properties except for drip loss (p<0.05). Also, except for cooking loss, ageing influenced the physicochemical and quality properties of meat; during 14 days of storage, proteolysis resulted in an increase of L* and b* values, drip loss and myofibrillar fragmentation index, and the decrease of a* value, expressed juice, shear force and sarcomere length. Proteome changes (myofibrillar proteins) during storage were investigated. Gel analysis revealed that 19 protein spots were significantly changed during 24, 72 and 168 h post-mortem. Fifteen spots were identified by MALDI-TOF/TOF mass spectrometer. Correlation analysis revealed significant correlations of actin, troponin T, capping protein, heat shock proteins (HSP) and desmin with physicochemical and quality properties of meat (p<0.05). Actin might be a potential protein marker for colour, tenderness and water-holding capacity, and HSP27 and desmin are good candidate markers for colour and tenderness, respectively. PMID:27956864

  9. Distal Insertions of the Biceps Femoris

    PubMed Central

    Branch, Eric A.; Anz, Adam W.

    2015-01-01

    Background: Avulsion of the biceps femoris from the fibula and proximal tibia is encountered in clinical practice. While the anatomy of the primary posterolateral corner structures has been qualitatively and quantitatively described, a quantitative analysis regarding the insertions of the biceps femoris on the fibula and proximal tibia is lacking. Purpose: To quantitatively assess the insertions of the biceps femoris, fibular collateral ligament (FCL), and anterolateral ligament (ALL) on the fibula and proximal tibia as well as establish relationships among these structures and to pertinent surgical anatomy. Study Design: Descriptive laboratory study. Methods: Dissections were performed on 12 nonpaired, fresh-frozen cadaveric specimens identifying the biceps femoris, FCL, and ALL, and their insertions on the proximal tibia and fibula. The footprint areas, orientations, and distances from relevant osseous landmarks were measured using a 3-dimensional coordinate measurement device. Results: Dissection produced 6 easily identifiable and reproducible anatomic footprints. Tibial footprints included the insertion of the ALL and an insertion of the biceps femoris (TBF). Fibular footprints included the insertion of the FCL, a distal insertion of the biceps femoris (DBF), a medial footprint of the biceps femoris (MBF), and a proximal footprint of the biceps femoris (PBF). The mean area of these footprints (95% CI) was as follows: ALL, 53.0 mm2 (38.4-67.6); TBF, 93.9 mm2 (72.0-115.8); FCL, 86.8 mm2 (72.3-101.2); DBF, 119 mm2 (91.1-146.9); MBF, 46.8 mm2 (29.0-64.5); and PBF, 215 mm2 (192.4-237.5). The mean distance (95% CI) from the Gerdy tubercle to the center of the ALL footprint was 24.3 mm (21.6-27.0) and to the center of the TBF was 22.5 mm (21.0-24.0). The center of the DBF was 8.68 mm (7.0-10.3) from the anterior border of the fibula, the center of the FCL was 14.6 mm (12.5-16.7) from the anterior border of the fibula and 20.7 mm (19.0-22.4) from the tip of the fibular

  10. Changes in the amounts of water-soluble umami-related substances in porcine longissimus and biceps femoris muscles during moist heat cooking.

    PubMed

    Sasaki, Keisuke; Motoyama, Michiyo; Mitsumoto, Mitsuru

    2007-10-01

    Time course changes in amounts of glutamic acid, total free amino acid, inosine monophosphate (IMP), and 2%-trichloroacetic acid-soluble oligopeptides in whole, muscle only, and cooking juice during wet-heat cooking in pork longissimus and biceps femoris muscles were investigated because the movements of umami-relevant substances during cooking treatment had not previously been clarified in detail. The amounts of glutamic acid, total free amino acid, and IMP significantly (P<.05) decreased and increased in muscle and cooking juice during 180min of cooking, respectively. The whole amounts of glutamic acid and total free amino acid remained unchanged during cooking treatment. The whole amount of IMP, however, increased significantly at 10min of cooking (P<.05) and was maintained after the 10-min period. The extramuscular oligopeptides amount increased significantly in response to the cooking treatment (P<.05). The intramuscular amount of oligopeptides decreased at 30min of cooking but increased significantly (P<.05) after 60min. The whole meat oligopeptides amount increased significantly during a 180-min cooking treatment (P<.05). These results indicate that glutamate, total free amino acid, and IMP were released from the muscle during cooking, and that IMP levels increased in the initial phase of cooking. In addition, oligopeptides increased during wet-heat cooking of pork muscles.

  11. A model of dynamic sacro-iliac joint instability from malrecruitment of gluteus maximus and biceps femoris muscles resulting in low back pain.

    PubMed

    Hossain, M; Nokes, L D M

    2005-01-01

    The objective of this work is to propose a biomechanical model of sacro-iliac joint dysfunction as a cause of low back pain. Sacro-iliac joint is known to be a source of low back pain. We also know that it is a very stable joint with little mobility. Surrounding lower limb and back muscles contribute a major part of this stability. Gait analysis studies have revealed an orderly sequence of muscle activation when we walk - that contributes to efficient stabilisation of the joint and effective weight transfer to the lower limb. Gluteus maximus fibres-lying almost perpendicular to the joint surfaces are ideally oriented for this purpose. Biceps femoris is another important muscle that can also influence joint stability by its proximal attachment to sacrotuberous ligament. Altered pattern of muscle recruitment has been observed in patients with low back pain. But we do not know the exact cause-effect relationship. Because of its position as a key linkage in transmission of weight from the upper limbs to the lower, poor joint stability could have major consequences on weight bearing. It is proposed that sacro-iliac joint dysfunction can result from malrecruitment of gluteus maximus motor units during weight bearing. This results in compensatory biceps over activation. The resulting soft tissue strain and joint instability may manifest itself in low back pain. If our hypothesis holds true, it may have positive implications for patients with sacro-iliac joint dysfunction - who could be offered a definite diagnosis and targeted physiotherapy. It may be possible to identify patients early in a primary care setting and offer direct physio referral. They could benefit from exercises to improve strengthening and recruitment of the affected muscles.

  12. Effects of live weight at slaughter on fatty acid composition of Longissimus dorsi and Biceps femoris muscles of indigenous Lori goat.

    PubMed

    Kiani, Ali; Fallah, Rozbeh

    2016-01-01

    This study aimed to determine fatty acid (FA) composition of Longissimus dorsi (LD) and Biceps femoris (BF) muscles of an Iranian indigenous goat (Lori goat) at two live weights at slaughter (LWS). Twenty male Lori goats (5 to 8 months) raised in nomadic system were slaughtered either at LWS less than 20 kg (light) or LWS more than 30 kg (heavy). Carcass dressing and FA composition of intramuscular fat of LD and BF muscles as well as cholesterol content of LD muscle were determined. Heavy goats had higher dressing percentage than light ones (42.7vs.39.3%, P < 0.01). The predominant n-6 FA were C18:2, and C20:4 while C22:5, C20:5, C18:3, C20:3, and C22:6 were the n-3 FA detected. Polyunsaturated and saturated FA contributed 22% and 36% of the total FA in both muscles, respectively. Palmitic acid (C16:0) of LD was higher in heavy compared to the light goats (P < 0.05). BF muscle had higher α-linolenic acid (18:3 n-3) as percentage than LD muscle (P < 0.05). The ratio of n-6/n-3 FA and polyunsaturated/saturated FA were 3.8 and 0.6, respectively. Cholesterol content of LD muscle of light and heavy goats were 71.2 ± 16 and 59.5 ± 14 mg per 100 g fresh meat respectively. In conclusion, desirable PUFA/SFA (0.6) and n-3/n-6 ratio (3.8) found in indigenous Lori goat propose healthy source of lean meat for the consumers.

  13. The use of dielectric properties and other physical analyses for assessing protein denaturation in beef biceps femoris muscle during cooking from 5 to 85°C.

    PubMed

    Brunton, N P; Lyng, J G; Zhang, L; Jacquier, J C

    2006-02-01

    Dielectric properties of beef biceps femoris muscle were recorded during heating (5-85°C) to assess their linkage to phase changes monitored by differential scanning calorimetry (DSC) and rheology. DSC indicated endotherms between 56 and 81°C corresponding to denaturation of actin, collagen and myosin. Matching changes in dielectric properties (dielectric constant (ε') and loss factor (ε″)) were noted at radio and/or microwave frequencies though the nature of the change differed depending upon frequency. The main observation in ε' was an increase above 65-66°C, most likely due to fluid release on collagen denaturation. This fluid plus liquid from myosin denaturation most likely solvated ions freed during myosin denaturation which manifested as an ε″ increase. However, it must be noted that meat structural protein denaturation is compounded with physical shrinkage which can also influence dielectric properties. Rheological parameters of beef muscle heated from 5 to 85°C also displayed marked changes relating to structural protein denaturation.

  14. Foam Rolling of Quadriceps Decreases Biceps Femoris Activation.

    PubMed

    Cavanaugh, Mark Tyler; Aboodarda, Saied Jalal; Hodgson, Daniel; Behm, David George

    2016-09-06

    Foam rolling has been shown to increase range of motion without subsequent performance impairments of the rolled muscle, however, there are no studies examining rolling effects on antagonist muscles. The objective of this study was to determine whether foam rolling the hamstrings and/or quadriceps would affect hamstrings and quadriceps activation in men and women. Recreationally active men (n=10, 25 ± 4.6 years, 180.1 ± 4.4 cm, 86.5 ± 15.7 kg) and women (n=8, 21.75 ± 3.2 years, 166.4 ± 8.8 cm, 58.9 ± 7.9 kg) had surface electromyographic activity analyzed in the dominant vastus lateralis (VL), vastus medialis (VM), and biceps femoris (BF) muscles upon a single leg landing from a hurdle jump under four conditions. Conditions included rolling of the hamstrings, quadriceps, both muscle groups and a control session. BF activation significantly decreased following quadriceps foam rolling (F(1,16) = 7.45, p = 0.015, -8.9%). There were no significant changes in quadriceps activation following hamstrings foam rolling. This might be attributed to the significantly greater levels of perceived pain with quadriceps rolling applications (F(1,18) = 39.067, p < 0.001, 98.2%). There were no sex-based changes in activation following foam rolling for VL (F(6,30) = 1.31, p = 0.283) VM (F(6,30) = 1.203, p = 0.332) or BF (F(6,36) = 1.703, p = 0.199). Antagonist muscle activation may be altered following agonist foam rolling, however, it can be suggested that any changes in activation are likely a result of reciprocal inhibition due to increased agonist pain perception.

  15. Use of Ultrasound to Monitor Biceps Femoris Mechanical Adaptations after Injury in a Professional Soccer Player.

    PubMed

    Kellis, Eleftherios; Galanis, Nikiforos; Chrysanthou, Chrysanthos; Kofotolis, Nikolaos

    2016-03-01

    This study examined the use of ultrasound to monitor changes in the long head of the biceps femoris (BF) architecture of aprofessional soccer player with acute first-time hamstring strain. The player followed a 14 session physiotherapy treatment until return to sport. The pennation angle and aponeurosis strain of the long head of the biceps femoris (BF) were monitored at 6 occasions (up until 1 year) after injury. The size of the scar / hematoma was reduced by 63.56% (length) and 67.9% (width) after the intervention and it was almost non-traceable one year after injury. The pennation angle of the fascicles underneath the scar showed a decline of 51.4% at the end of the intervention while an increase of 109.2% of the fascicles which were closer to deep aponeurosis was observed. In contrast, pennation angle of fascicles located away from the injury site were relatively unaffected. The treatment intervention resulted in a 57.9% to 77.3% decline of maximum strain per unit of MVC moment and remained similar one year after the intervention. This study provided an example of the potential use of ultrasound-based parameters to link the mechanical adaptations of the injured muscle to specific therapeutic intervention. Key pointsChanges in fascicle orientation after biceps femoris mild tear were reduced after a 28 day intervention and remained similar one year after injury.Tendon/aponeurosis strain per unit of moment of force decreased during the course of the therapeutic intervention.Future studies could utilize ultrasonography to monitor mechanical responses after various types of hamstring injury and interventions in order to improve criteria for a safe return to sport.

  16. Use of Ultrasound to Monitor Biceps Femoris Mechanical Adaptations after Injury in a Professional Soccer Player

    PubMed Central

    Kellis, Eleftherios; Galanis, Nikiforos; Chrysanthou, Chrysanthos; Kofotolis, Nikolaos

    2016-01-01

    This study examined the use of ultrasound to monitor changes in the long head of the biceps femoris (BF) architecture of aprofessional soccer player with acute first-time hamstring strain. The player followed a 14 session physiotherapy treatment until return to sport. The pennation angle and aponeurosis strain of the long head of the biceps femoris (BF) were monitored at 6 occasions (up until 1 year) after injury. The size of the scar / hematoma was reduced by 63.56% (length) and 67.9% (width) after the intervention and it was almost non-traceable one year after injury. The pennation angle of the fascicles underneath the scar showed a decline of 51.4% at the end of the intervention while an increase of 109.2% of the fascicles which were closer to deep aponeurosis was observed. In contrast, pennation angle of fascicles located away from the injury site were relatively unaffected. The treatment intervention resulted in a 57.9% to 77.3% decline of maximum strain per unit of MVC moment and remained similar one year after the intervention. This study provided an example of the potential use of ultrasound-based parameters to link the mechanical adaptations of the injured muscle to specific therapeutic intervention. Key points Changes in fascicle orientation after biceps femoris mild tear were reduced after a 28 day intervention and remained similar one year after injury. Tendon/aponeurosis strain per unit of moment of force decreased during the course of the therapeutic intervention. Future studies could utilize ultrasonography to monitor mechanical responses after various types of hamstring injury and interventions in order to improve criteria for a safe return to sport. PMID:26957929

  17. The effectiveness of two novel techniques in establishing the mechanical and contractile responses of biceps femoris.

    PubMed

    Ditroilo, Massimiliano; Hunter, Angus M; Haslam, Samuel; De Vito, Giuseppe

    2011-08-01

    Portable tensiomyography (TMG) and myotonometry (MMT) devices have been developed to measure mechanical and contractile properties of skeletal muscle. The aim of this study was to explore the sensitivity of the aforementioned techniques in detecting a change in passive mechanical properties of the biceps femoris (BF) muscle as a result of change in knee joint angle (i.e. muscle length). BF responses were assessed in 16 young participants (23.4 ± 4.9 years), at three knee joint angles (0°, 45° and 90°), for maximal isometric torque (MIT) along with myo-electrical activity. Contractile and mechanical properties were measured in a relaxed state. Inter-day reliability of the TMG and MMT was also assessed. MIT changed significantly (p < 0.01) across the three angles, so did stiffness and other parameters measured with MMT (p < 0.01). Conversely, TMG could detect changes only at two knee angles (0° and 45°, p < 0.01), when there is enough tension in the muscle. Reliability was overall insufficient for TMG whilst absolute reliability was excellent (coefficient of variation < 5%) for MMT. The ability of MMT more than TMG to detect an inherent change in stiffness can be conceivably exploited in a number of clinical/therapeutic applications that have to do with unnatural changes in passive muscle stiffness.

  18. Effect of 8-week high-intensity stretching training on biceps femoris architecture.

    PubMed

    Freitas, Sandro R; Mil-Homens, Pedro

    2015-06-01

    Previous studies have reported no changes on muscle architecture (MA) after static stretching interventions; however, authors have argued that stretching duration and intensity may not have been sufficient. A high-intensity stretching intervention targeting the knee flexors with an 8-week duration was conducted to observe the effects on biceps femoris long head (BF) architecture. Participants (n = 5) performed an average of 3.1 assisted-stretching sessions per week, whereas a control group (n = 5) did not perform stretching. The knee extension passive maximal range of motion (ROM), and BF fascicle length (FL), fascicle angle, and muscle thickness were assessed before and after the intervention. A significant increase was observed for FL (+12.3 mm, p = 0.04) and maximal ROM (+14.2°, p = 0.04) for the stretching group after the intervention. No significant changes were observed for the control group in any parameter. An 8-week high-intensity stretching program was observed to efficiently increase the BF FL, as well as the knee extension maximal ROM. Stretching intensity and duration may play an important role on MA adaptation.

  19. EMG amplitude of the biceps femoris during jumping compared to landing movements.

    PubMed

    Padulo, Johnny; Tiloca, Alessandra; Powell, Douglas; Granatelli, Giampietro; Bianco, Antonino; Paoli, Antonio

    2013-01-01

    Hamstrings injury is a common occurrence in athletic performance. These injuries tend to occur during a deceleration or landing task suggesting the negative work may be a key component in hamstrings injury. The purpose of this study was to investigate the muscular activity (EMG) of the biceps femoris (BF) in different phases (concentric vs. eccentric) of a Counter Movement Jump (CMJ), Squat Jump (SJ) and the Braking Phase (BP) of a landing task. Twelve female volleyball players performed 5 CMJs, SJs and BPs while surface EMG was recorded using a MuscleLab (BoscoSystem(TM), Norway). EMG values were normalized to an maximal voluntary contraction. A repeated measures analysis of variance (ANOVA) was used to compare mean normalized EMG values of the concentric and eccentric portions of the CMJ with the BP and SJ. The ANOVA revealed significantly lower BF activation in the concentric and eccentric portions of the CMJ compared to the BP (64%, p < 0.001) and SJ (7%, p = 0.02), respectively. These findings suggest that the CMJ relies on a greater contribution of elastic tissues during the concentric and eccentric portions of the movement and thus requires less muscle activation of the BF.

  20. Calcific tendinitis of biceps femoris: an unusual site and cause for lateral knee pain.

    PubMed

    Chan, Warwick; Chase, Helen Emily; Cahir, John G; Walton, Neil Patrick

    2016-07-29

    A 37-year-old man presented to the acute knee and sports medicine clinic with atraumatic lateral knee pain. He had point tenderness over the lateral aspect of his knee which had not settled with anti-inflammatory medications. Imaging revealed a large opaque lesion lateral to the knee and although there was no clear mechanism, injury to the posterolateral corner was considered. An MRI subsequently revealed a rare case of calcific tendinitis to the biceps femoris tendon insertion. This condition was self-limiting and did not require interventions such as steroid injections. This is the first reported case of calcific tendinitis of biceps femoris as a cause of acute knee pain.

  1. Biceps femoris and semitendinosus tendon/aponeurosis strain during passive and active (isometric) conditions.

    PubMed

    Kellis, Eleftherios

    2016-02-01

    The purpose of this study was to quantify strain and elongation of the long head of the biceps femoris (BFlh) and the semitendinosus (ST) tendon/aponeurosis. Forty participants performed passive knee extension trials from 90° of knee flexion to full extension (0°) followed by ramp isometric contractions of the knee flexors at 0°, 45° and 90° of knee flexion. Two ultrasound probes were used to visualize the displacement of BFlh and ST tendon/aponeurosis. Three-way analysis of variance designs indicated that: (a) Tendon/aponeurosis (passive) elongation and strain were higher for the BFlh than the ST as the knee was passively extended (p<0.05), (b) contraction at each angular position was accompanied by a smaller BFlh tendon/aponeurosis (active) strain and elongation than the ST at higher levels of effort (p<0.05) and (c) combined (passive and active) strain was significantly higher for the BFlh than ST during ramp contraction at 0° but the opposite was observed for the 45° and 90° flexion angle tests (p<0.05). Passive elongation of tendon/aponeurosis has an important effect on the tendon/aponeurosis behavior of the hamstrings and may contribute to a different loading of muscle fibers and tendinous tissue between BFlh and ST.

  2. Anatomy of the long head of biceps femoris: An ultrasound study.

    PubMed

    Tosovic, D; Muirhead, J C; Brown, J M M; Woodley, S J

    2016-09-01

    Hamstring strains, particularly involving the long head of biceps femoris (BFlh) at the proximal musculotendinous junction (MTJ), are commonly experienced by athletes. With the use of diagnostic ultrasound increasing, an in-depth knowledge of normal ultrasonographic anatomy is fundamental to better understanding hamstring strain. The aim of this study was to describe the architecture of BFlh, using ultrasonography, in young men and cadaver specimens. BFlh morphology was examined in 19 healthy male participants (mean age 21.6 years) using ultrasound. Muscle, tendon and MTJ lengths were recorded and architectural parameters assessed at four standardised points along the muscle. Measurement accuracy was validated by ultrasound and dissection of BFlh in six male cadaver lower limbs (mean age 76 years). Intra-rater reliability of architectural parameters was examined for repeat scans, image analysis and dissection measurements. Distally the BFlh muscle had significantly (P < 0.05) shorter fascicles and larger pennation angles than proximal sites. Agreement between ultrasound and dissection (cadaver study) was excellent for all architectural parameters, except pennation angle (PA), and MTJ length. All other measures demonstrated good-excellent repeatability. BFlh is not uniform in architecture when imaged using ultrasound. It is likely that its distal-most segment is better suited for force production in comparison to the more proximal segments, which show excursive potential, traits which possibly contribute to the high rate of injury at the proximal MTJ. The data presented in this study provide specific knowledge of the normal ultrasonographic anatomy of BFlh, which should be of assistance in analysing BFlh injury via imaging. Clin. Anat. 29:738-745, 2016. © 2016 Wiley Periodicals, Inc.

  3. Influence of extended aging on beef quality characteristics and sensory perception of steaks from the biceps femoris and semimembranosus.

    PubMed

    Colle, M J; Richard, R P; Killinger, K M; Bohlscheid, J C; Gray, A R; Loucks, W I; Day, R N; Cochran, A S; Nasados, J A; Doumit, M E

    2016-09-01

    The objective was to determine the influence of post-fabrication aging (2, 14, 21, 42, and 63days) on beef quality characteristics and consumer sensory perception of biceps femoris (BF) and semimembranosus (SM) steaks. Lipid oxidation and aerobic plate counts increased (P<0.05) with longer aging periods and retail display times. An aging period by day of retail display interaction (P<0.05) was observed for a* and b* values of the BF and SM. Warner-Bratzler shear force values decreased (P<0.05) with longer aging for the SM, while no difference was observed for the BF. Consumer panel results revealed that longer aging periods increased (P<0.05) acceptability of the SM, tenderness of both muscles, and tended to increase (P=0.07) juiciness of the SM. Our results show that extended aging reduces retail color stability yet has positive effects on consumer perception of tenderness of both muscles and overall acceptability of the SM.

  4. The relationship between shear force, compression, collagen characteristics, desmin degradation and sarcomere length in lamb biceps femoris.

    PubMed

    Starkey, Colin P; Geesink, Geert H; van de Ven, Remy; Hopkins, David L

    2017-04-01

    This study aimed to identity the relationships between known variants of tenderness (collagen content (total and soluble), desmin degradation and sarcomere length) and shear force and compression in the biceps femoris aged for 14days from 112 mixed sex lambs. Desmin degradation was related to compression (P<0.05) such that as desmin degradation increased compression decreased. Sarcomere length (SL) was related to shear force (P<0.05), such that as SL increased shear force declined. Shear force was also related to compression (P<0.05), and soluble collagen (P<0.05), with male lambs producing higher shear force values than females (4.4±1.72N: P<0.05) when adjusted for compression, sarcomere length and soluble collagen. The findings from this experiment indicate that the known variants (soluble collagen, sarcomere length and desmin degradation) are related to shear force and compression in ovine biceps femoris.

  5. Reduced biceps femoris myoelectrical activity influences eccentric knee flexor weakness after repeat sprint running.

    PubMed

    Timmins, R G; Opar, D A; Williams, M D; Schache, A G; Dear, N M; Shield, A J

    2014-08-01

    The aim of this study was to determine whether declines in knee flexor strength following overground repeat sprints were related to changes in hamstrings myoelectrical activity. Seventeen recreationally active men completed maximal isokinetic concentric and eccentric knee flexor strength assessments at 180°/s before and after repeat sprint running. Myoelectrical activity of the biceps femoris (BF) and medial hamstrings (MHs) was measured during all isokinetic contractions. Repeated measures mixed model [fixed factors = time (pre- and post-repeat sprint) and leg (dominant and nondominant), random factor = participants] design was fitted with the restricted maximal likelihood method. Repeat sprint running resulted in significant declines in eccentric, and concentric, knee flexor strength (eccentric = 26 ± 4 Nm, 15% P < 0.001; concentric 11 ± 2 Nm, 10% P < 0.001). Eccentric BF myoelectrical activity was significantly reduced (10%; P = 0.035). Concentric BF and all MH myoelectrical activity were not altered. The declines in maximal eccentric torque were associated with the change in eccentric BF myoelectrical activity (P = 0.013). Following repeat sprint running, there were preferential declines in the myoelectrical activity of the BF, which explained declines in eccentric knee flexor strength.

  6. Effects of aging and freezing/thawing sequence on quality attributes of bovine Mm. gluteus medius and biceps femoris

    PubMed Central

    Kim, Hyun-Wook; Brad Kim, Yuan H.

    2017-01-01

    Objective The effects of aging and freezing/thawing sequence on color, physicochemical, and enzymatic characteristics of two beef muscles (Mm. gluteus medius, GM and biceps femoris, BF) were evaluated. Methods Beef muscles at 3 d postmortem were assigned to four different combinations of aging and freezing/thawing sequence as follows; aging at 2°C for 3 wk (A3, never-frozen control), freezing at −28°C for 2 wk then thawing (F2, frozen/thawed-only), aging at 2°C for 3 wk, freezing at −28°C for 2 wk then thawing (A3F2), and freezing at −28°C for 2 wk, thawing then further aging at 2°C for 3 wk (F2A3). Results No significant interactions between different aging/freezing/thawing treatments and muscle type on all measurements were found. Postmortem aging, regardless of aging/freezing/thawing sequence, had no impact on color stability of frozen/thawed beef muscles (p<0.05). F2A3 resulted in higher purge loss than F2 and A3F2 treatments (p<0.05). A3F2 and F2A3 treatments resulted in lower shear force of beef muscles compared to F2 (p<0.05). Although there was no significant difference in glutathione peroxidase (GSH-Px) activity, F2A3 had the highest β-N-acetyl glucominidase (BNAG) activity in purge, but the lowest BNAG activity in muscle (p<0.05). GM muscle exhibited higher total color changes and purge loss, and lower GSH-Px activity than BF muscle. Conclusion The results from this present study indicate that different combinations of aging/freezing/thawing sequence would result in considerable impacts on meat quality attributes, particularly thaw/purge loss and tenderness. Developing a novel freezing strategy combined with postmortem aging will be beneficial for the food/meat industry to maximize its positive impacts on tenderness, while minimizing thaw/purge loss of frozen/thawed meat. PMID:27488843

  7. The biceps muscle from shoulder to elbow.

    PubMed

    Stevens, Kathryn; Kwak, Andrew; Poplawski, Stephen

    2012-09-01

    The biceps brachii plays an integral role in movement of the shoulder and elbow, and pathology can occur in athletes of all ages. Injuries of the proximal biceps tendon can be seen in overhead athletes as a result of chronic impingement, tendon instability, or tensile overload, often with accompanying lesions of the labrum or rotator cuff. Presentation may be insidious or can be precipitated by an acute event. Injuries to the distal biceps are more common in athletes involved in strength training such as weightlifters, or occasionally in contact sports. Although injury to the proximal and distal biceps can often be diagnosed clinically, MRI is an excellent imaging modality to evaluate the extent of disease and involvement of adjacent structures. This article reviews the anatomy of the biceps brachii from the shoulder to elbow and discusses commonly occurring pathology of the biceps and adjacent anatomical structures.

  8. A Comparison of Gluteus Maximus, Biceps Femoris, and Vastus Lateralis Electromyography Amplitude in the Parallel, Full, and Front Squat Variations in Resistance-Trained Females.

    PubMed

    Contreras, Bret; Vigotsky, Andrew D; Schoenfeld, Brad J; Beardsley, Chris; Cronin, John

    2016-02-01

    Front, full, and parallel squats are some of the most popular squat variations. The purpose of this investigation was to compare mean and peak electromyography (EMG) amplitude of the upper gluteus maximus, lower gluteus maximus, biceps femoris, and vastus lateralis of front, full, and parallel squats. Thirteen healthy women (age = 28.9 ± 5.1 y; height = 164 ± 6.3 cm; body mass = 58.2 ± 6.4 kg) performed 10 repetitions of their estimated 10-repetition maximum of each respective variation. There were no statistical (P ≤ .05) differences between full, front, and parallel squats in any of the tested muscles. Given these findings, it can be concluded that the front, full, or parallel squat can be performed for similar EMG amplitudes. However, given the results of previous research, it is recommended that individuals use a full range of motion when squatting, assuming full range can be safely achieved, to promote more favorable training adaptations. Furthermore, despite requiring lighter loads, the front squat may provide a similar training stimulus to the back squat.

  9. A Comparison of Gluteus Maximus, Biceps Femoris, and Vastus Lateralis Electromyographic Activity in the Back Squat and Barbell Hip Thrust Exercises.

    PubMed

    Contreras, Bret; Vigotsky, Andrew D; Schoenfeld, Brad J; Beardsley, Chris; Cronin, John

    2015-12-01

    The back squat and barbell hip thrust are both popular exercises used to target the lower body musculature; however, these exercises have yet to be compared. Therefore, the purpose of this study was to compare the surface electromyographic (EMG) activity of the upper and lower gluteus maximus, biceps femoris, and vastus lateralis between the back squat and barbell hip thrust. Thirteen trained women (n = 13; age = 28.9 years; height = 164 cm; mass = 58.2 kg) performed estimated 10-repetition maximums (RM) in the back squat and barbell hip thrust. The barbell hip thrust elicited significantly greater mean (69.5% vs 29.4%) and peak (172% vs 84.9%) upper gluteus maximus, mean (86.8% vs 45.4%) and peak (216% vs 130%) lower gluteus maximus, and mean (40.8% vs 14.9%) and peak (86.9% vs 37.5%) biceps femoris EMG activity than the back squat. There were no significant differences in mean (99.5% vs 110%) or peak (216% vs 244%) vastus lateralis EMG activity. The barbell hip thrust activates the gluteus maximus and biceps femoris to a greater degree than the back squat when using estimated 10RM loads. Longitudinal training studies are needed to determine if this enhanced activation correlates with increased strength, hypertrophy, and performance.

  10. [Paragliding-associated bilateral partial rupture of the rectus femoris muscle].

    PubMed

    Schulze Bertelsbeck, D; Veelken, D

    2004-12-01

    Pain in the thigh or groin due to a rupture of the rectus femoris muscle is rather uncommon. We report on a patient with a bilateral rupture of the rectus femoris muscle that occurred due to a landing maneuver while para-gliding. The diagnosis was confirmed by ultrasound and MRI. Additionally, an old unilateral anterior cruciate ligament rupture was present. As a functional deficit of the quadriceps muscle could not be observed, a primarily conservative treatment seems to be appropriate.

  11. Giant pseudocyst of the rectus femoris muscle--repetitive strain injury in recreational soccer player.

    PubMed

    Cicvarić, Tedi; Lucin, Ksenija; Roth, Sandor; Ivancić, Aldo; Marinović, Marin; Santić, Veljko

    2010-04-01

    We report a case of a traumatic pseudocyst, in a recreational soccer player, after rupture of rectus femoris muscle. 37-year-old male, with history of repetitive painful accidents, was examined because of a double fist-sized mass in the anterior thigh. Ultrasound examination revealed a cystic mass in the rectus femoris muscle. Surgical removal of the mass and proximal remnant of muscle was done. Primary healing and functional recovery was achieved. Histological analysis revealed pseudocyst filled with degenerating clot and surrounded with thick fibrous capsule. The repetitive strain muscle injury, with prolonged period of healing, can occur like pseudocyst.

  12. Muscle hardness characteristics of the masseter muscle after repetitive muscle activation: comparison to the biceps brachii muscle.

    PubMed

    Kashima, Koji; Higashinaka, Shuichi; Watanabe, Naoshi; Maeda, Sho; Shiba, Ryosuke

    2004-10-01

    The purpose of this study was to compare hardness characteristics of the masseter muscle to those of the biceps brachii muscle during repetitive muscle movements. Seventeen asymptomatic female subjects participated in this study. Each subject, on separate days, undertook a 5-minute unilateral chewing gum task on the right side and a 5-minute flexion-extension exercise on the right hand with a 2kg dumbbell. Using a handheld hardness meter, muscle hardness was measured in the right masseter and in the biceps brachii muscle at eight time points (before the task, immediately after the task, and at 1, 3, 5, 10, 30, and 60 minutes after the task), and the data obtained before and after the task on each muscle were compared. Comparisons of the normalized data were also performed between the two muscles at each time point. As a result, a significant increase in muscle hardness was seen at 1 minute after the task in the biceps brachii muscle (p=0.0093). In contrast, the masseter muscle showed a tendency to lower hardness, with the lowest point of hardness occurring at 10 minutes after the task (p = 0.0160). Between the two muscles, there was a difference in the normalized data immediately after the task, and at 1, 5, and 10 minutes after the task (0.01 muscle hardness characteristics of the masseter muscle completely differed from those of the biceps brachii muscle after repetitive muscle activation.

  13. Rabbit rectus femoris muscle for ischemia-reperfusion studies: an improved model.

    PubMed

    Hoballah, J J; Mohan, C R; Schipper, P H; Chalmers, R T; Corry, D C; Corson, J D

    1996-11-01

    The rabbit rectus femoris muscle was evaluated as a potential model for skeletal muscle reperfusion injury studies. Six white New Zealand rabbits were used. On one randomly selected hind limb, ischemia was induced by direct clamping of the rectus femoris muscle's vascular pedicle. On the other side, blood flow was interrupted by clamping the femoral artery above and below the origin of the vascular pedicle that supplies the rectus femoris muscle. The duration of normothermic ischemia was 4 hr and was followed by 24 hr of normothermic reperfusion. The interruption and restoration of blood flow was monitored using a laser flow meter. The rectus femoris muscles were weighed on a suspension spring balance prior to ischemia and at the end of reperfusion to estimate edema. The extent of muscle necrosis was determined using planimetry following staining with nitroblue tetrazolium. The muscle necrosis obtained by direct clamping of the vascular pedicle (66.9 +/- 14.3%) was significantly greater than that obtained by indirect clamping (18.6 +/- 11.4%) (P < 0.03 by t test). Unlike the indirect clamping technique, direct clamping achieved a good magnitude of muscle necrosis, thus allowing that specific model to be used in skeletal muscle reperfusion injury studies. The muscle weight gain observed in the direct clamping muscle group was 19.8 +/- 9.0% and was significantly greater than that observed in the opposite group being 6.3 +/- 6.5% (P < 0.05 by t test). The rabbit rectus femoris muscle is a suitable model for evaluating skeletal muscle reperfusion injury provided that direct clamping of the vascular pedicle is utilized.

  14. The force-length curves of the human rectus femoris and gastrocnemius muscles in vivo.

    PubMed

    Winter, Samantha L; Challis, John H

    2010-02-01

    For a physiologically realistic joint range of motion and therefore range of muscle fiber lengths, only part of the whole muscle force-length curve can be used in vivo; that is, only a section of the force-length curve is expressed. Previous work has determined that the expressed section of the force-length curve for individual muscles can vary between subjects; however, the degree of intersubject variability is different for different muscles. This study determined the expressed section of both the rectus femoris and gastrocnemius--muscles with very different ratios of tendon slack length to muscle fiber optimum length--for 28 nonspecifically trained subjects to test the hypothesis that the value of this ratio affects the amount of variability in the expressed section. The force-length curves of the two muscles were reconstructed from moment-angle data using the method of Herzog & ter Keurs (1988). There was no relationship between the expressed sections of the force-length curve for the two muscles. Less variability was found in the expressed section of the gastrocnemius compared with the rectus femoris, supporting the hypothesis. The lack of relationship between the expressed sections of the two muscles has implications for motor control and for training muscle for rehabilitation.

  15. Hemipelvectomy for Buttock Tumors Utilizing an Anterior Myocutaneous Flap of Quadriceps Femoris Muscle

    PubMed Central

    Sugarbaker, Paul H.; Chretien, Paul A.

    1983-01-01

    Hemipelvectomy utilizing an anterior myocutaneous flap is indicated for aggressive tumors of the buttock and proximal portion of the posterior thigh. A large operative defect created posteriorly by amputation of the lower extremity, hemipelvis, and buttock is covered by a myocutaneous flap of quadriceps femoris muscle and overlying skin and subcutaneous tissue. The superficial femoral artery is preserved to sustain the myocutaneous flap. ImagesFig. 2A,B,C.Fig. 2A,B,C. PMID:6848048

  16. Rectus femoris muscle injuries in football: a clinically relevant review of mechanisms of injury, risk factors and preventive strategies.

    PubMed

    Mendiguchia, Jurdan; Alentorn-Geli, Eduard; Idoate, Fernando; Myer, Gregory D

    2013-04-01

    Quadriceps muscle strains frequently occur in sports that require repetitive kicking and sprinting, and are common in football in its different forms around the world. This paper is a review of aetiology, mechanism of injury and the natural history of rectus femoris injury. Investigating the mechanism and risk factors for rectus femoris muscle injury aims to allow the development of a framework for future initiatives to prevent quadriceps injury in football players.

  17. A Comparison of Gluteus Maximus, Biceps Femoris, and Vastus Lateralis Electromyography Amplitude for the Barbell, Band, and American Hip Thrust Variations.

    PubMed

    Contreras, Bret; Vigotsky, Andrew D; Schoenfeld, Brad J; Beardsley, Chris; Cronin, John

    2016-06-01

    Bridging exercise variations are well researched and commonly employed for both rehabilitation and sport performance. However, resisted bridge exercise variations have not yet been compared in a controlled experimental study. Therefore, the purpose of this study was to compare the differences in upper and lower gluteus maximus, biceps femoris, and vastus lateralis electromyography (EMG) amplitude for the barbell, band, and American hip thrust variations. Thirteen healthy female subjects (age = 28.9 y; height = 164.3 cm; body mass = 58.2 kg) familiar with the hip thrust performed 10 repetitions of their 10-repetition maximum of each variation in a counterbalanced and randomized order. The barbell hip thrust variation elicited statistically greater mean gluteus maximus EMG amplitude than the American and band hip thrusts, and statistically greater peak gluteus maximus EMG amplitude than the band hip thrust (P ≤ .05), but no other statistical differences were observed. It is recommended that resisted bridging exercise be prescribed according to the individual's preferences and desired outcomes.

  18. Measurement of the quadriceps femoris muscle using magnetic resonance and ultrasound imaging.

    PubMed Central

    Walton, J M; Roberts, N; Whitehouse, G H

    1997-01-01

    OBJECTIVES: To define a method for measurement of the cross sectional area and volume of the quadriceps femoris muscle using magnetic resonance imaging (MRI) in conjunction with stereology, and to compare the results of measurements obtained by the MRI method with those obtained by the conventional method of static B-mode ultrasound in order to evaluate whether MRI is a reliable alternative to ultrasound. METHODS: A preliminary MRI study was undertaken on a single female volunteer in order to optimise the scanning technique and sampling design for estimating the muscle volume using the Cavalieri method. Ten healthy volunteers participated in the method comparison study. Each volunteer underwent static B-mode ultrasonography, immediately followed by MRI. The cross sectional area of the quadriceps femoris was estimated at the junction of the proximal one third and distal two thirds of the thigh, and seven systematic sections of the thigh were obtained in order to estimate muscle volume by both modalities. RESULTS: Seven sections through the muscle are required to achieve a coefficient of error of 4-5%. There was no significant difference in the cross sectional area estimates or volume estimates when ultrasound and MRI were compared. CONCLUSION: Muscle cross sectional area and volume can be measured without bias by MRI in conjunction with stereological methods and the method is a reliable alternative to static B-mode ultrasound for this purpose. Images Figure 1 Figure 4 Figure 5 PMID:9132215

  19. Muscle spindle composition and distribution in human young masseter and biceps brachii muscles reveal early growth and maturation.

    PubMed

    Osterlund, Catharina; Liu, Jing-Xia; Thornell, Lars-Eric; Eriksson, Per-Olof

    2011-04-01

    Significant changes in extrafusal fiber type composition take place in the human masseter muscle from young age, 3-7 years, to adulthood, in parallel with jaw-face skeleton growth, changes of dentitions and improvement of jaw functions. As motor and sensory control systems of muscles are interlinked, also the intrafusal fiber population, that is, muscle spindles, should undergo age-related changes in fiber type appearance. To test this hypothesis, we examined muscle spindles in the young masseter muscle and compared the result with previous data on adult masseter spindles. Also muscle spindles in the young biceps brachii muscle were examined. The result showed that muscle spindle composition and distribution were alike in young and adult masseter. As for the adult masseter, young masseter contained exceptionally large muscle spindles, and with the highest spindle density and most complex spindles found in the deep masseter portion. Hence, contrary to our hypothesis, masseter spindles do not undergo major morphological changes between young age and adulthood. Also in the biceps, young spindles were alike adult spindles. Taken together, the results showed that human masseter and biceps muscle spindles are morphologically mature already at young age. We conclude that muscle spindles in the human young masseter and biceps precede the extrafusal fiber population in growth and maturation. This in turn suggests early reflex control and proprioceptive demands in learning and maturation of jaw motor skills. Similarly, well-developed muscle spindles in young biceps reflect early need of reflex control in learning and performing arm motor behavior.

  20. Angle- and gender-specific quadriceps femoris muscle recruitment and knee extensor torque.

    PubMed

    Pincivero, Danny M; Salfetnikov, Yuliya; Campy, Robert M; Coelho, Alan J

    2004-11-01

    The objectives were to examine knee angle-, and gender-specific knee extensor torque output and quadriceps femoris (QF) muscle recruitment during maximal effort, voluntary contractions. Fourteen young adult men and 15 young adult women performed three isometric maximal voluntary contractions (MVC), in a random order, with the knee at 0 degrees (terminal extension), 10 degrees, 30 degrees, 50 degrees, 70 degrees, and 90 degrees flexion. Knee extensor peak torque (PT), and average torque (AT) were expressed in absolute (N m), relative (N m kg(-1)) and allometric-modeled (N m kg(-n)) units. Vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF) muscle EMG signals were full-wave rectified and integrated over the middle 3 s of each contraction, averaged over the three trials at each knee angle, and normalized to the activity recorded at 0 degrees. Muscle recruitment efficiency was calculated as the ratio of the normalized EMG of each muscle to the allometric-modeled average torque (normalized to the values at 0 degrees flexion), and expressed as a percent. Men generated significantly greater knee extensor PT and AT than women in absolute, relative and allometric-modeled units. Absolute and relative PT and AT were significantly highest at 70 degrees, while allometric-modeled values were observed to increase significantly across knee joint angles 10-90 degrees. VM EMG was significantly greater than the VL and RF muscles across all angles, and followed a similar pattern to absolute knee extensor torque. Recruitment efficiency improved across knee joint angles 10-90 degrees and was highest for the VL muscle. VM recruitment efficiency improved more than the VL and RF muscles across 70-90 degrees flexion. The findings demonstrate angle-, and gender-specific responses of knee extensor torque to maximal-effort contractions, while superficial QF muscle recruitment was most efficient at 90 degrees, and less dependent on gender.

  1. Measurement of rectus femoris muscle velocities during patellar tendon jerk using vector tissue doppler imaging.

    PubMed

    Sikdar, Siddhartha; Lebiedowska, Maria; Eranki, Avinash; Garmirian, Lindsay; Damiano, Diane

    2009-01-01

    We have developed a vector tissue Doppler imaging (TDI) system based on a clinical scanner that can be used to measure muscle velocities independent of the direction of motion. This method overcomes the limitations of conventional Doppler ultrasound, which can only measure velocity components along the ultrasound beam. In this study, we utilized this method to investigate the rectus femoris muscle velocities during a patellar tendon jerk test. Our goal was to investigate whether the muscle elongation velocities during a brisk tendon tap fall within the normal range of velocities that are expected due to rapid stretch of limb segments. In a preliminary study, we recruited six healthy volunteers (three men and three women) following informed consent. The stretch reflex response to tendon tap was evaluated by measuring: (1) the tapping force using an accelerometer instrumented to the neurological hammer (2) the angular velocities of the knee extension and flexion using a electrogoniometer (3) reflex activation using electromyography (EMG) and (4) muscle elongation, extension and flexion velocities using vector TDI. The passive joint angular velocity was linearly related to the passive muscle elongation velocity (R(2)=0.88). The maximum estimated joint angular velocity corresponding to muscle elongation due to tendon tap was less than 8.25 radians/s. This preliminary study demonstrates the feasibility of vector TDI for measuring longitudinal muscle velocities and indicates that the muscle elongation velocities during a clinical tendon tap test are within the normal range of values for rapid limb stretch encountered in daily life. With further refinement, vector TDI could become a powerful method for quantitative evaluation of muscle motion in musculoskeletal disorders.

  2. Relationships between Muscle Architecture of Rectus Femoris and Functional Parameters of Knee Motion in Adults with Down Syndrome

    PubMed Central

    Micale, Marco; Cioni, Matteo

    2016-01-01

    This study was designed to measure in vivo muscle architecture of the rectus femoris in adults with Down syndrome, testing possible relationships with functional parameters of the knee motion. Ten adults with Down syndrome and ten typically developed participated in the study. Pennation angle and thickness of the rectus femoris and subcutaneous layer of the thigh were measured via ultrasound imaging. Knee kinematics and electromyographic activity of the rectus femoris were recorded during free leg dropping. Muscle thickness was reduced and subcutaneous layer was thicker in persons with Down syndrome with respect to typically developed adults, but there were no differences in the pennation angle. The area of the rectus femoris EMG activity during the leg flexion was greater in Down syndrome with respect to typically developed adults. The leg movement velocity was lower in Down people than in controls, but the knee excursion was similar between the groups. Functional parameters correlated with pennation angle in the persons with Down syndrome and with muscle thickness in typically developed persons. The description of muscle architecture and the relationships between morphological and functional parameters may provide insights on the limits and the opportunities to overcome the inherent biomechanical instability in Down syndrome. PMID:27896273

  3. Relationships between Muscle Architecture of Rectus Femoris and Functional Parameters of Knee Motion in Adults with Down Syndrome.

    PubMed

    Valle, Maria Stella; Casabona, Antonino; Micale, Marco; Cioni, Matteo

    2016-01-01

    This study was designed to measure in vivo muscle architecture of the rectus femoris in adults with Down syndrome, testing possible relationships with functional parameters of the knee motion. Ten adults with Down syndrome and ten typically developed participated in the study. Pennation angle and thickness of the rectus femoris and subcutaneous layer of the thigh were measured via ultrasound imaging. Knee kinematics and electromyographic activity of the rectus femoris were recorded during free leg dropping. Muscle thickness was reduced and subcutaneous layer was thicker in persons with Down syndrome with respect to typically developed adults, but there were no differences in the pennation angle. The area of the rectus femoris EMG activity during the leg flexion was greater in Down syndrome with respect to typically developed adults. The leg movement velocity was lower in Down people than in controls, but the knee excursion was similar between the groups. Functional parameters correlated with pennation angle in the persons with Down syndrome and with muscle thickness in typically developed persons. The description of muscle architecture and the relationships between morphological and functional parameters may provide insights on the limits and the opportunities to overcome the inherent biomechanical instability in Down syndrome.

  4. Analysis of three different equations for predicting quadriceps femoris muscle strength in patients with COPD *

    PubMed Central

    Nellessen, Aline Gonçalves; Donária, Leila; Hernandes, Nidia Aparecida; Pitta, Fabio

    2015-01-01

    Abstract Objective: To compare equations for predicting peak quadriceps femoris (QF) muscle force; to determine the agreement among the equations in identifying QF muscle weakness in COPD patients; and to assess the differences in characteristics among the groups of patients classified as having or not having QF muscle weakness by each equation. Methods: Fifty-six COPD patients underwent assessment of peak QF muscle force by dynamometry (maximal voluntary isometric contraction of knee extension). Predicted values were calculated with three equations: an age-height-weight-gender equation (Eq-AHWG); an age-weight-gender equation (Eq-AWG); and an age-fat-free mass-gender equation (Eq-AFFMG). Results: Comparison of the percentage of predicted values obtained with the three equations showed that the Eq-AHWG gave higher values than did the Eq-AWG and Eq-AFFMG, with no difference between the last two. The Eq-AHWG showed moderate agreement with the Eq-AWG and Eq-AFFMG, whereas the last two also showed moderate, albeit lower, agreement with each other. In the sample as a whole, QF muscle weakness (< 80% of predicted) was identified by the Eq-AHWG, Eq-AWG, and Eq-AFFMG in 59%, 68%, and 70% of the patients, respectively (p > 0.05). Age, fat-free mass, and body mass index are characteristics that differentiate between patients with and without QF muscle weakness. Conclusions: The three equations were statistically equivalent in classifying COPD patients as having or not having QF muscle weakness. However, the Eq-AHWG gave higher peak force values than did the Eq-AWG and the Eq-AFFMG, as well as showing greater agreement with the other equations. PMID:26398750

  5. Mechanics of the muscles crossing the hip joint during sprint running.

    PubMed

    Nagano, Yasuharu; Higashihara, Ayako; Takahashi, Kazumasa; Fukubayashi, Toru

    2014-01-01

    We aimed to demonstrate the changes over time in the lengths and forces of the muscles crossing the hip joint during overground sprinting and investigate the relationships between muscle lengths and muscle-tendon unit forces - particularly peak biceps femoris force. We obtained three-dimensional kinematics during 1 running cycle from 8 healthy sprinters sprinting at maximum speed. Muscle lengths and muscle-tendon unit forces were calculated for the iliacus, rectus femoris, gluteus maximus, and biceps femoris muscles of the target leg as well as the contralateral iliacus and rectus femoris. Our results showed that during sprinting, the muscles crossing the hip joint demonstrate a stretch-shortening cycle and 1 or 2 peak forces. The timing of peak biceps femoris force, expressed as a percentage of the running cycle (mean [SD], 80.5 [2.9]%), was synchronous with those of the maximum biceps femoris length (82.8 [1.9]%) and peak forces of the gluteus maximus (83.8 [9.1]%), iliacus (81.1 [5.2]%), and contralateral iliacus (78.5 [5.8]%) and also that of the peak pelvic anterior tilt. The force of the biceps femoris appeared to be influenced by the actions of the muscles crossing the hip joint as well as by the pelvic anterior tilt.

  6. Comparison of EMG activity between maximal manual muscle testing and cybex maximal isometric testing of the quadriceps femoris.

    PubMed

    Lin, Hui-Ting; Hsu, Ar-Tyan; Chang, Jia-Hao; Chien, Chi-Sheng; Chang, Guan-Liang

    2008-02-01

    Two methods have been used to produce a maximal voluntary isometric contraction (MVIC) of the superficial quadriceps femoris muscles for normalization of electromyographic (EMG) data. The purposes of this study were to compare the myoelectic activity of MVIC of manual muscle testing (MMT) versus Cybex maximal isometric testing. Eighteen normal subjects were recruited. MMT and Cybex testing for MVIC of the dominant leg were performed. EMG activities of the vastus medialis, vastus lateralis and rectus femoris were recorded during MMT and Cybex trials. EMG amplitude and median frequency obtained from the two methods (MMT and Cybex testing) were used for statistical analysis of these three muscles. Statistically, the difference in the mean of the EMG signal amplitude and median frequency between MMT and Cybex testing were not significant. Considering cost and time, MMT for MVIC technique appears to be reliable and highly valuable.

  7. Is myoelectric activity distributed equally within the rectus femoris muscle during loaded, squat exercises?

    PubMed

    de Souza, Leonardo Mendes Leal; da Fonseca, Desirée Barros; Cabral, Hélio da Veiga; de Oliveira, Liliam Fernandes; Vieira, Taian Martins

    2017-04-01

    Recent evidence suggests different regions of the rectus femoris (RF) muscle respond differently to squat exercises. Such differential adaptation may result from neural inputs distributed locally within RF, as previously reported for isometric contractions, walking and in response to fatigue. Here we therefore investigate whether myoelectric activity distributes evenly within RF during squat. Surface electromyograms (EMGs) were sampled proximally and distally from RF with arrays of electrodes, while thirteen healthy volunteers performed 10 consecutive squats with 20% and 40% of their body weight. The root mean square (RMS) value, computed separately for thirds of the concentric and eccentric phases, was considered to assess the proximo-distal changes in EMG amplitude during squat. The channels with variations in EMG amplitude during squat associated with shifts in the muscle innervation zone were excluded from analysis. No significant differences were observed between RF regions when considering squat phases and knee joint angles individually (P>0.16) while a significant interaction between phase and knee joint angle with detection site was observed (P<0.005). For the two loads considered, proximal RMS values were greater during the eccentric phase and for the more flexed knee joint position (P<0.001). Our results suggest inferences on the degree of RF activation during squat must be made cautiously from surface EMGs. Of more practical relevance, there may be a potential for the differential adaption of RF proximal and distal regions to squat exercises.

  8. Functional Assessment of Skeletal Muscle Regeneration Utilizing Homologous Extracellular Matrix as Scaffolding

    DTIC Science & Technology

    2010-01-01

    should also serve as a scaffold and allow the incorporation of regenerat- ing muscle, connective, nerve , and blood vessel tissues. Several types of...To close the wound, the biceps femoris muscle was reattached to the tibia using simple, interrupted, polypropylene suture (Prolene 5-0; Ethicon, San...from the superficial skin and biceps femoris as well as the deep soleus and plan- taris. The nerve branch innervating the medial GAS was transected to

  9. New aspects of the influence of quadriceps femoris muscle stimulation course on functional capabilities of the organism.

    PubMed

    Arkov, V V; Abramova, T F; Nikitina, T M; Afanasjeva, D A; Anosova, A A; Milenina, A I; Tonevitsky, A G

    2010-08-01

    We studied the effect of a course of electrical stimulation of the quadriceps femoris muscle with submaximal contraction under biofeedback conditions on functional capabilities of the organism. In addition to the known effects, electrostimulation course modulated the content of intra- and extracellular fluid and increases MDA content and creatine phosphokinase activity, which can be a manifestation of overtreatment. Impairment of body static balance after the course was revealed. Thus, monitoring of the effects of electrostimulation is required during the course.

  10. Permanent disabilities in the displaced muscle from rupture of the long head tendon of the biceps.

    PubMed

    Deutch, Søren R; Gelineck, John; Johannsen, Hans Viggo; Sneppen, Otto

    2005-06-01

    Patients with a displaced muscle belly because of rupture of the long head biceps tendon were investigated for local pain and other disabilities, together with strength and endurance loss. Eleven patients (median age 59 years, minimum follow-up 6 months) were included, and minimum follow-up was 6 months. Magnetic resonance imaging (MRI) of both upper arms allowed investigation of muscle atrophy and evaluation of any other degenerative signs in the displaced muscle. All patients reported pain or disability locally in the displaced muscle in certain situations, and strength and endurance were reduced by 25%. MRI revealed the displaced muscle to be unreduced in size and with no signs of degeneration. Generally, operative reattachment of the displaced muscle is not advocated in middle-aged or older patients. In order to elucidate this subject, we present a retrospective consecutive series of patients with considerable disabilities in the displaced muscle belly independent of shoulder disabilities.

  11. Effect of eccentric exercise with reduced muscle glycogen on plasma interleukin-6 and neuromuscular responses of musculus quadriceps femoris.

    PubMed

    Gavin, James P; Myers, Stephen D; Willems, Mark E T

    2016-07-01

    Eccentric exercise can result in muscle damage and interleukin-6 (IL-6) secretion. Glycogen availability is a potent stimulator of IL-6 secretion. We examined effects of eccentric exercise in a low-glycogen state on neuromuscular function and plasma IL-6 secretion. Twelve active men (23 ± 4 yr, 179 ± 5 cm, 77 ± 10 kg, means ± SD) completed two downhill treadmill runs (gradient, -12%, 5 × 8 min; speed, 12.1 ± 1.1 km/h) with normal (NG) and reduced muscle glycogen (RG) in randomized order and at least 6 wk apart. Muscle glycogen was reduced using an established cycling protocol until exhaustion and dietary manipulation the evening before the morning run. Physiological responses were measured up to 48 h after the downhill runs. During recovery, force deficits of musculus quadriceps femoris by maximal isometric contractions were similar. Changes in low-frequency fatigue were larger with RG. Voluntary activation and plasma IL-6 levels were similar in recovery between conditions. It is concluded that unaccustomed, damaging eccentric exercise with low muscle glycogen of the m. quadriceps femoris 1) exacerbated low-frequency fatigue but 2) had no additional effect on IL-6 secretion. Neuromuscular impairment after eccentric exercise with low muscle glycogen appears to have a greater peripheral component in early recovery.

  12. Real-time measurement of rectus femoris muscle kinematics during drop jump using ultrasound imaging: a preliminary study.

    PubMed

    Eranki, Avinash; Cortes, Nelson; Ferencek Gregurić, Zrinka; Kim, John J; Sikdar, Siddhartha

    2012-01-01

    We have developed an office based vector tissue Doppler imaging (vTDI) that can be used to quantitatively measure muscle kinematics using ultrasound. The goal of this preliminary study was to investigate if vTDI measures are repeatable and can be used robustly to measure and understand the kinematics of the rectus femoris muscle during a drop jump task. Data were collected from 8 healthy volunteers. Vector TDI along with a high speed camera video was used to better understand the dynamics of the drop jump. Our results indicate that the peak resultant vector velocity of the rectus femoris immediately following landing was repeatable across trials (intraclass correlation coefficient=0.9).The peak velocity had a relatively narrow range in 6 out of 8 subjects (48-62 cm/s), while in the remaining two subjects it exceeded 70 cm/s. The entire drop jump lasted for 1.45 0.27 seconds. The waveform of muscle velocity could be used to identify different phases of the jump. Also, the movement of the ultrasound transducer holder was minimal with peak deflection of 0.91 0.54 degrees over all trials. Vector TDI can be implemented in a clinical setting using an ultrasound system with a research interface to better understand the muscle kinematics in patients with ACL injuries.

  13. Intramuscular variation in fresh ham muscle color

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This experiment was conducted to characterize a defect involving pale muscle tissue in the superficial, ventral portion of ham muscles, resulting in two-toned appearance of cured ham products. Biceps femoris muscles (n = 200), representing 3 production systems, were obtained from the ham-boning lin...

  14. Mechanical muscle fibre conduction velocity of the biceps as measured by a new seismic technique.

    PubMed

    Journée, H L; de Jonge, A B; van Calker, R; Gräler, G

    1995-01-01

    A recently-developed technique, called seismic myography (SMG) has the characteristic of recording fast micro-mechanical response times. These times can be determined with sub-millisecond accuracy. The response times can be compared to response times of EMG recordings. The "muscular electro-seismic response" (MESR) latencies, due to direct electrical stimulation of the biceps muscle, are used for explorative measurements of the mechanical conduction velocity of the muscle fibres. The measurements are performed by means of a general-purpose physiological multimeter which is equiped with the micro-seismic function. Measurements are performed on two healthy subjects, aged 22 years. The MESR-latencies are measured along a medial and a lateral trajectory on their biceps muscles. The MESR-latencies at stimulus-cathodal to seismic transducer distances of 2,0-3,5 cm, are in the range of 2.0-3.8 ms, while at distances in the range of 7.5-8.9 cm the MESR-latencies varied between 3.4 and 4.7 ms. The calculated mechanical muscle fibre conduction velocities (MMFCV) are in the range between 36 and 89 m/s. There is a reproducability error of maximum 20%. The MMFCV's of the lateral and medial trajectory do not differ within the accuracy of the present method. However, the MMFCV's are considerably higher than the electrical muscle fibre conduction velocities of MUAPS ((E)MFCV). Some aspects of the MMFCV and possible consequences to surface EMG recordings are discussed. It is concluded that this seismic method for measuring MMFCV is a new accessible and simple to handle tool for the description of muscle function, and offers an interesting new contribution in experimental muscular research.

  15. Results of ulnar nerve neurotization to biceps brachii muscle in brachial plexus injury

    PubMed Central

    Rezende, Marcelo Rosa De; Rabelo, Neylor Teofilo Araújo; Silveira, Clóvis Castanho; Petersen, Pedro Araújo; Paula, Emygdio José Leomil De; Mattar, Rames

    2012-01-01

    OBJECTIVE: To evaluate the factors influencing the results of ulnar nerve neurotization at the motor branch of the brachii biceps muscle, aiming at the restoration of elbow flexion in patients with brachial plexus injury. METHODS: 19 patients, with 18 men and 1 woman, mean age 28.7 years. Eight patients had injury to roots C5-C6 and 11, to roots C5-C6-C7. The average time interval between injury and surgery was 7.5 months. Four patients had cervical fractures associated with brachial plexus injury. The postoperative follow-up was 15.7 months. RESULTS: Eight patients recovered elbow flexion strength MRC grade 4; two, MRC grade 3 and nine, MRC <3. There was no impairment of the previous ulnar nerve function. CONCLUSION: The surgical results of ulnar nerve neurotization at the motor branch of brachii biceps muscle are dependent on the interval between brachial plexus injury and surgical treatment, the presence of associated fractures of the cervical spine and occipital condyle, residual function of the C8-T1 roots after the injury and the involvement of the C7 root. Signs of reinnervation manifested up to 3 months after surgery showed better results in the long term. Level of Evidence: IV, Case Series. PMID:24453624

  16. Rupture of the distal biceps tendon combined with a supinator muscle tear in a 51-year-old woman: a case report.

    PubMed

    Nayyar, Samir; Quirno, Martin; Hasan, Saqib; Rybak, Leon; Meislin, Robert J

    2011-01-01

    Distal biceps tendon rupture is a relatively uncommon occurrence in the general female population, and to our knowledge, has not been reported in association with a supinator muscle tear. We report a case of 51-year-old woman who experienced sharp pain in her forearm and elbow after lifting a heavy object. History and physical examination raised suspicion for a distal biceps tendon rupture. MRI imaging determined a combined distal biceps tendon tear with a supinator muscle tear with subsequent confirmation at surgery. Surgical repair was performed for the distal biceps tendon only through a single incision approach using the Endobutton technique.

  17. The effects of kinesio taping on architecture, strength and pain of muscles in delayed onset muscle soreness of biceps brachii.

    PubMed

    Lee, Yong Sin; Bae, Sea Hyun; Hwang, Jin Ah; Kim, Kyung Yoon

    2015-02-01

    [Purpose] This study aimed to confirm the effects of kinesio taping (KT) on muscle function and pain due to delayed onset muscle soreness (DOMS) of the biceps brachii. [Subjects and Methods] Thirty-seven subjects with induced DOMS were randomized into either Group I (control, n=19) or Group II (KT, n=18). Outcome measures were recorded before the intervention (application of KT) and at 24, 48, and 72 hours after the intervention. DOMS was induced, and muscle thickness was measured using ultrasonic radiography. Maximal voluntary isometric contraction (%MVIC) was measured via electromyography (EMG). Subjective pain was measured using a visual analogue scale (VAS). [Results] Group I exhibited a positive correlation between muscle thickness and elapsed time from intervention (24, 48, and 72 hours post induction of DOMS); they also showed a significant decrease in MVIC(%). Group II showed significant increases in muscle thickness up to the 48-hour interval post induction of DOMS, along with a significant decrease in MVIC (%). However, in contrast to Group I, Group II did not show a significant difference in muscle thickness or MVIC (%) at the 72-hour interval in comparison with the values prior to DOMS induction. [Conclusion] In adults with DOMS, activation of muscles by applying KT was found to be an effective and faster method of recovering muscle strength than rest alone.

  18. The effects of kinesio taping on architecture, strength and pain of muscles in delayed onset muscle soreness of biceps brachii

    PubMed Central

    Lee, Yong Sin; Bae, Sea Hyun; Hwang, Jin Ah; Kim, Kyung Yoon

    2015-01-01

    [Purpose] This study aimed to confirm the effects of kinesio taping (KT) on muscle function and pain due to delayed onset muscle soreness (DOMS) of the biceps brachii. [Subjects and Methods] Thirty-seven subjects with induced DOMS were randomized into either Group I (control, n=19) or Group II (KT, n=18). Outcome measures were recorded before the intervention (application of KT) and at 24, 48, and 72 hours after the intervention. DOMS was induced, and muscle thickness was measured using ultrasonic radiography. Maximal voluntary isometric contraction (%MVIC) was measured via electromyography (EMG). Subjective pain was measured using a visual analogue scale (VAS). [Results] Group I exhibited a positive correlation between muscle thickness and elapsed time from intervention (24, 48, and 72 hours post induction of DOMS); they also showed a significant decrease in MVIC(%). Group II showed significant increases in muscle thickness up to the 48-hour interval post induction of DOMS, along with a significant decrease in MVIC (%). However, in contrast to Group I, Group II did not show a significant difference in muscle thickness or MVIC (%) at the 72-hour interval in comparison with the values prior to DOMS induction. [Conclusion] In adults with DOMS, activation of muscles by applying KT was found to be an effective and faster method of recovering muscle strength than rest alone. PMID:25729190

  19. Effects of combined application of progressive resistance training and Russian electrical stimulation on quadriceps femoris muscle strength in elderly women with knee osteoarthritis.

    PubMed

    Park, Seong Hoon; Hwangbo, Gak

    2015-03-01

    [Purpose] The aim of this study was to investigate the effects of combined application of progressive resistance training and Russian electrical stimulation on quadriceps femoris muscle strength in elderly women with osteoarthritis of the knee. [Subjects] Thirty women over 65 years of age diagnosed with knee osteoarthritis participated in the present study. The subjects were randomly assigned to a control group (n=10), a progressive resistance training group (n=10), or a Russian electrical stimulation group (n=10). [Methods] Each group was treated 3 times weekly for 8 weeks, and each session lasted 45 minutes. Muscle strength was assessed by measuring the peak torque of the quadriceps femoris muscle. Outcome measurements were performed at baseline and at the fourth and eighth weeks of the treatment period. [Results] All groups showed significant intragroup differences in the quadriceps femoris muscle peak torque after the treatment intervention. There were significant intergroup differences between the Russian electrical stimulation group and the other groups. [Conclusion] The results of this study suggest that combined application of progressive resistance training and Russian electrical stimulation can be effective in strengthening the quadriceps femoris muscle in elderly women with knee osteoarthritis.

  20. Atlas of the muscle motor points for the lower limb: implications for electrical stimulation procedures and electrode positioning.

    PubMed

    Botter, Alberto; Oprandi, Gianmosè; Lanfranco, Fabio; Allasia, Stefano; Maffiuletti, Nicola A; Minetto, Marco Alessandro

    2011-10-01

    The aim of the study was to investigate the uniformity of the muscle motor point location for lower limb muscles in healthy subjects. Fifty-three subjects of both genders (age range: 18-50 years) were recruited. The muscle motor points were identified for the following ten muscles of the lower limb (dominant side): vastus medialis, rectus femoris, and vastus lateralis of the quadriceps femoris, biceps femoris, semitendinosus, and semimembranosus of the hamstring muscles, tibialis anterior, peroneus longus, lateral and medial gastrocnemius. The muscle motor point was identified by scanning the skin surface with a stimulation pen electrode and corresponded to the location of the skin area above the muscle in which an electrical pulse evoked a muscle twitch with the least injected current. For each investigated muscle, 0.15 ms square pulses were delivered through the pen electrode at low current amplitude (<10 mA) and frequency (2 Hz). 16 motor points were identified in the 10 investigated muscles of almost all subjects: 3 motor points for the vastus lateralis, 2 motor points for rectus femoris, vastus medialis, biceps femoris, and tibialis anterior, 1 motor point for the remaining muscles. An important inter-individual variability was observed for the position of the following 4 out of 16 motor points: vastus lateralis (proximal), biceps femoris (short head), semimembranosus, and medial gastrocnemius. Possible implications for electrical stimulation procedures and electrode positioning different from those commonly applied for thigh and leg muscles are discussed.

  1. Effects of fast and slow squat exercises on the muscle activity of the paretic lower extremity in patients with chronic stroke

    PubMed Central

    Choi, Young-Ah; Kim, Jin-Seop; Lee, Dong-Yeop

    2015-01-01

    [Purpose] The purpose of this study was to investigate the effects of the speed of squat exercises on paretic lower extremity muscle activity in patients with hemiplegia following a stroke. [Subjects and Methods] Ten stroke patients performed fast and slow squat exercises for 2 seconds and 8 seconds, respectively. The muscle activities of the paretic and non-paretic sides of the rectus femoris muscle, the biceps femoris muscle, and the tibialis anterior muscle were assessed and compared using surface electromyography. [Results] The paretic side of the rectus femoris muscle showed statistically significant differences in the fast squat exercise group, which demonstrated the highest muscle activity during the rapid return to the upright position. [Conclusion] The rectus femoris muscle showed the highest muscle activity during the return to the upright position during the fast squat exercise, which indicates that the rectus femoris muscle is highly active during the fast squat exercise. PMID:26356385

  2. Effects of fast and slow squat exercises on the muscle activity of the paretic lower extremity in patients with chronic stroke.

    PubMed

    Choi, Young-Ah; Kim, Jin-Seop; Lee, Dong-Yeop

    2015-08-01

    [Purpose] The purpose of this study was to investigate the effects of the speed of squat exercises on paretic lower extremity muscle activity in patients with hemiplegia following a stroke. [Subjects and Methods] Ten stroke patients performed fast and slow squat exercises for 2 seconds and 8 seconds, respectively. The muscle activities of the paretic and non-paretic sides of the rectus femoris muscle, the biceps femoris muscle, and the tibialis anterior muscle were assessed and compared using surface electromyography. [Results] The paretic side of the rectus femoris muscle showed statistically significant differences in the fast squat exercise group, which demonstrated the highest muscle activity during the rapid return to the upright position. [Conclusion] The rectus femoris muscle showed the highest muscle activity during the return to the upright position during the fast squat exercise, which indicates that the rectus femoris muscle is highly active during the fast squat exercise.

  3. The origin of activity in the biceps brachii muscle during voluntary contractions of the contralateral elbow flexor muscles.

    PubMed

    Zijdewind, Inge; Butler, Jane E; Gandevia, Simon C; Taylor, Janet L

    2006-11-01

    During strong voluntary contractions, activity is not restricted to the target muscles. Other muscles, including contralateral muscles, often contract. We used transcranial magnetic stimulation (TMS) to analyse the origin of these unintended contralateral contractions (termed "associated" contractions). Subjects (n = 9) performed maximal voluntary contractions (MVCs) with their right elbow-flexor muscles followed by submaximal contractions with their left elbow flexors. Electromyographic activity (EMG) during the submaximal contractions was matched to the associated EMG in the left biceps brachii during the right MVC. During contractions, TMS was delivered to the motor cortex of the right or left hemisphere and excitatory motor evoked potentials (MEPs) and inhibitory (silent period) responses recorded from left biceps. Changes at a spinal level were investigated using cervicomedullary stimulation to activate corticospinal paths (n = 5). Stimulation of the right hemisphere produced silent periods of comparable duration in associated and voluntary contractions (218 vs 217 ms, respectively), whereas left hemisphere stimulation caused a depression of EMG but no EMG silence in either contraction. Despite matched EMG, MEPs elicited by right hemisphere stimulation were approximately 1.5-2.5 times larger during associated compared to voluntary contractions (P < 0.005). Similar inhibition of the associated and matched voluntary activity during the silent period suggests that associated activity comes from the contralateral hemisphere and that motor areas in this (right) hemisphere are activated concomitantly with the motor areas in the left hemisphere. Comparison of the MEPs and subcortically evoked potentials implies that cortical excitability was greater in associated contractions than in the matched voluntary efforts.

  4. Four-headed biceps brachii, three-headed coracobrachialis muscles associated with arterial and nervous anomalies in the upper limb

    PubMed Central

    Catli, Mehmet Mutlu; Ozsoy, Umut; Kaya, Yasemin; Hizay, Arzu; Yildirim, Fatos Belgin

    2012-01-01

    A four-headed biceps brachii muscle and three-headed coracobrachialis muscle, high-originated radial artery and communication between the median and musculocutaneous nerves have been well documented in the available literature. However co-existence of these variations is rare. In this study we aimed to describe multiple variations in the upper limb and discuss their co-existence from clinical and embryological points of view. PMID:22822469

  5. Kinesiology Taping does not Modify Electromyographic Activity or Muscle Flexibility of Quadriceps Femoris Muscle: A Randomized, Placebo-Controlled Pilot Study in Healthy Volleyball Players

    PubMed Central

    Halski, Tomasz; Dymarek, Robert; Ptaszkowski, Kuba; Słupska, Lucyna; Rajfur, Katarzyna; Rajfur, Joanna; Pasternok, Małgorzata; Smykla, Agnieszka; Taradaj, Jakub

    2015-01-01

    Background Kinesiology taping (KT) is a popular method of supporting professional athletes during sports activities, traumatic injury prevention, and physiotherapeutic procedures after a wide range of musculoskeletal injuries. The effectiveness of KT in muscle strength and motor units recruitment is still uncertain. The objective of this study was to assess the effect of KT on surface electromyographic (sEMG) activity and muscle flexibility of the rectus femoris (RF), vastus lateralis (VL), and vastus medialis (VM) muscles in healthy volleyball players. Material/Methods Twenty-two healthy volleyball players (8 men and 14 women) were included in the study and randomly assigned to 2 comparative groups: “kinesiology taping” (KT; n=12; age: 22.30±1.88 years; BMI: 22.19±4.00 kg/m2) in which KT application over the RF muscle was used, and “placebo taping” (PT; n=10; age: 21.50±2.07 years; BMI: 22.74±2.67 kg/m2) in which adhesive nonelastic tape over the same muscle was used. All subjects were analyzed for resting sEMG activity of the VL and VM muscles, resting and functional sEMG activity of RF muscle, and muscle flexibility of RF muscle. Results No significant differences in muscle flexibility of the RF muscle and sEMG activity of the RF, VL, and VM muscles were registered before and after interventions in both groups, and between the KT and PT groups (p>0.05). Conclusions The results show that application of the KT to the RF muscle is not useful to improve sEMG activity. PMID:26232122

  6. Nerve root distribution of deltoid and biceps brachii muscle in cervical spondylotic myelopathy: a potential risk factor for postoperative shoulder muscle weakness after posterior decompression.

    PubMed

    Yonemura, Hiroshi; Kaneko, Kazuo; Taguchi, Toshihiko; Fujimoto, Hideaki; Toyoda, Kouichiro; Kawai, Shinya

    2004-01-01

    To investigate the nerve root distribution of deltoid and biceps brachii muscle, compound muscle action potentials (CMAPs) were recorded intraoperatively following nerve root stimulation in cervical spondylotic myelopathy. A total of 19 upper limbs in 12 patients aged 55-72 years (mean, 65.5 years) with cervical spondylotic myelopathy were examined. CMAPs were recorded from deltoid and biceps brachii muscle following C5 and C6 root stimulation. Although both C5 and C6 roots were innervated for deltoid and biceps brachii muscle in all subjects, the amplitude ratio of CMAPs (C5/C6) differed individually depending on the symptomatic intervertebral levels of the spinal cord. The C5 root predominantly innervated both deltoid and biceps brachii in patients with symptomatic cord lesions at the C4-C5 intervertebral level compared to patients with symptomatic cord lesions at the C5-C6 intervertebral level. Although no patients sustained postoperative radiculopathy in our study, severe weakness and unfavorable recovery are expected when the C5 root in patients with C4-C5 myelopathy is damaged. From the electrophysiological aspect, C4-C5 cord lesions are likely to be a potential risk factor for postoperative shoulder muscle weakness in patients with compressive cervical myelopathy.

  7. Motor unit synchronization in FDI and biceps brachii muscles of strength-trained males.

    PubMed

    Fling, Brett W; Christie, Anita; Kamen, Gary

    2009-10-01

    Motor unit (MU) synchronization is the simultaneous or near-simultaneous firing of two MUs which occurs more often than would be expected by chance. The present study sought to investigate the effects of exercise training, muscle group, and force level, by comparing the magnitude of synchronization in the biceps brachii (BB) and first dorsal interosseous (FDI) muscles of untrained and strength-trained college-aged males at two force levels, 30% of maximal voluntary contraction (MVC) and 80% MVC. MU action potentials were recorded directly via an intramuscular needle electrode. The magnitude of synchronization was assessed using previously-reported synchronization indices: k', E, and CIS. Synchronization was significantly higher in the FDI than in the BB. Greater synchronization was observed in the strength-trained group with CIS, but not with E or k'. Also, synchronization was significantly greater at 80% MVC than at 30% MVC with E, but only moderately greater with CIS and there was no force difference with k'. Synchronization prevalence was found to be greater in the BB (80.1%) than in the FDI (71.5%). Thus, although the evidence is a bit equivocal, it appears that MU synchronization is greater at higher forces, and greater in strength-trained individuals than in untrained subjects.

  8. Disorders of the proximal and distal aspects of the biceps muscle.

    PubMed

    McDonald, Lucas S; Dewing, Christopher B; Shupe, Paul G; Provencher, Matthew T

    2013-07-03

    PROXIMAL ASPECT OF BICEPS: Tenodesis of the long head of the biceps may offer improved cosmesis, improved strength, and diminished activity-related pain compared with tenotomy, although comparative studies have shown similar outcomes in some patient populations. DISTAL ASPECT OF BICEPS: Operative treatment of both partial and complete distal biceps ruptures results in better outcomes compared with nonoperative care, although the optimal technique and fixation are yet to be determined. Nonoperative management is an acceptable treatment for patients willing to accept some loss of forearm supination and elbow flexion strength as well as changes in endurance and cosmesis.

  9. Electromyographic activity of the biceps brachii after exercise-induced muscle damage.

    PubMed

    Ahmadi, Sirous; Sinclair, Peter J; Foroughi, Nasim; Davis, Glen M

    2007-01-01

    It is well known that strenuous eccentric exercise may result in muscle damage. We proposed that vigorous eccentric exercise (EE) would impair myoelectric activity of the biceps brachii. This study utilised a 7-day prospective time-series design. Ten healthy males performed a session of 70 maximal EE elbow flexion contractions. Analysis of surface electromyography activity (sEMG) was performed on the signals recorded during isometric contractions at 50% (IC50) and 80% (IC80) of maximum voluntary isometric torque (MVT), deriving RMS and MDF as sEMG parameters. Linear regression of the RMS and MDF time-series (20-s sustained IC50 and IC80) was used to extract intercepts and slopes of these signals on each day. Plasma creatine kinase activity (CK), MVT, arm circumference, subjective perception of soreness and elbow joint range of motion were also measured to assess effectiveness of EE to evoke muscle damage. CK increased over resting values until day 5 after EE, and remained significantly (p < 0.05) elevated even on day 7. MVT had decreased to 45% of its initial value by day 2 after EE, and remained significantly depressed for the following 6 days. In addition, muscle soreness and arm circumference increased, and range of motion decreased after EE. A significant shift of MDF intercept towards lower frequencies at both IC50 and IC80 was observed after EE in the exercised arm, and these values gradually recovered within the next 3 days during IC50. Although there were some changes in RMS values, these alterations were persistent in both control and exercised arms, and did not follow a consistent pattern. In conclusion, a prolonged reduction in MDF intercept was observed after EE, but this was not closely time-associated with the biochemical, anthropometric or functional markers of muscle damage. Compared to RMS, MDF was a more consistent measure to reflect changes in sEMG. Key pointsEMG can be a useful tool to detect exercise-induced muscle damage,MDF decreased after

  10. Two dimensional spatial coherence of the natural vibrations of the biceps brachii muscle generated during voluntary contractions.

    PubMed

    Archer, Akibi; Sabra, Karim G

    2010-01-01

    Surface mechanomyograms (S-MMGs) are recorded from low frequency (〈100 Hz) mechanical oscillations that are naturally generated by skeletal muscle during voluntary contractions. This study investigates a method to determine the propagation directionality of the S-MMG waves. A 3×5 grid of skin mounted accelerometers was mounted on the biceps brachii muscle during submaximal voluntary contractions. This method resulted in findings that the propagation directionality of the S-MMGs are frequency dependent. At high frequencies (>25 Hz), high spatial coherence values were only measured for sensor pairs aligned along the proximal to distal (i.e. longitudinal) orientation, thus indicating that coherent S-MMG were mainly propagating along the muscle fibers direction of the biceps brachii at those frequencies. On the other hand, at lower frequencies (〈25 Hz), the S-MMG spatial coherence values did not exhibit a specific directionality. This method provides results that have an important implication of finding the average phase velocity of the propagating S-MMG wave, which can be used to determine viscoelastic properties of skeletal muscles.

  11. Functional differences in the activity of the hamstring muscles with increasing running speed.

    PubMed

    Higashihara, Ayako; Ono, Takashi; Kubota, Jun; Okuwaki, Toru; Fukubayashi, Toru

    2010-08-01

    In this study, we examined hamstring muscle activation at different running speeds to help better understand the functional characteristics of each hamstring muscle. Eight healthy male track and field athletes (20.1 +/- 1.1 years) performed treadmill running at 50%, 75%, 85%, and 95% of their maximum velocity. Lower extremity kinematics of the hip and knee joint were calculated. The surface electromyographic activities of the biceps femoris and semitendinosus muscles were also recorded. Increasing the running speed from 85% to 95% significantly increased the activation of the hamstring muscles during the late swing phase, while lower extremity kinematics did not change significantly. During the middle swing phase, the activity of the semitendinosus muscle was significantly greater than that of the biceps femoris muscle at 75%, 85%, and 95% of running speed. Statistically significant differences in peak activation time were observed between the biceps femoris and semitendinosus during 95%max running (P < 0.05 for stance phase, P < 0.01 for late swing phase). Significant differences in the activation patterns between the biceps femoris and semitendinosus muscles were observed as running speed was increased, indicating that complex neuromuscular coordination patterns occurred during the running cycle at near maximum sprinting speeds.

  12. Electromyographic, cerebral, and muscle hemodynamic responses during intermittent, isometric contractions of the biceps brachii at three submaximal intensities.

    PubMed

    Bhambhani, Yagesh; Fan, Jui-Lin; Place, Nicolas; Rodriguez-Falces, Javier; Kayser, Bengt

    2014-01-01

    This study examined the electromyographic, cerebral and muscle hemodynamic responses during intermittent isometric contractions of biceps brachii at 20, 40, and 60% of maximal voluntary contraction (MVC). Eleven volunteers completed 2 min of intermittent isometric contractions (12/min) at an elbow angle of 90° interspersed with 3 min rest between intensities in systematic order. Surface electromyography (EMG) was recorded from the right biceps brachii and near infrared spectroscopy (NIRS) was used to simultaneously measure left prefrontal and right biceps brachii oxyhemoglobin (HbO2), deoxyhemoglobin (HHb), and total hemoglobin (Hbtot). Transcranial Doppler ultrasound was used to measure middle cerebral artery velocity (MCAv) bilaterally. Finger photoplethysmography was used to record beat-to-beat blood pressure and heart rate. EMG increased with force output from 20 to 60% MVC (P < 0.05). Cerebral HbO2 and Hbtot increased while HHb decreased during contractions with differences observed between 60% vs. 40% and 20% MVC (P < 0.05). Muscle HbO2 decreased while HHb increased during contractions with differences being observed among intensities (P < 0.05). Muscle Hbtot increased from rest at 20% MVC (P < 0.05), while no further change was observed at 40 and 60% MVC (P > 0.05). MCAv increased from rest to exercise but was not different among intensities (P > 0.05). Force output correlated with the root mean square EMG and changes in muscle HbO2 (P < 0.05), but not changes in cerebral HbO2 (P > 0.05) at all three intensities. Force output declined by 8% from the 1st to the 24th contraction only at 60% MVC and was accompanied by systematic increases in RMS, cerebral HbO2 and Hbtot with a leveling off in muscle HbO2 and Hbtot. These changes were independent of alterations in mean arterial pressure. Since cerebral blood flow and oxygenation were elevated at 60% MVC, we attribute the development of fatigue to reduced muscle oxygen availability rather than impaired central

  13. Muscle Activation Patterns During Different Squat Techniques.

    PubMed

    Slater, Lindsay V; Hart, Joseph M

    2017-03-01

    Slater, LV, and Hart, JM. Muscle activation patterns during different squat techniques. J Strength Cond Res 31(3): 667-676, 2017-Bilateral squats are frequently used exercises in sport performance programs. Lower extremity muscle activation may change based on knee alignment during the performance of the exercise. The purpose of this study was to compare lower extremity muscle activation patterns during different squat techniques. Twenty-eight healthy, uninjured subjects (19 women, 9 men, 21.5 ± 3 years, 170 ± 8.4 cm, 65.7 ± 11.8 kg) volunteered. Electromyography (EMG) electrodes were placed on the vastus lateralis, vastus medialis, rectus femoris, biceps femoris, and the gastrocnemius of the dominant leg. Participants completed 5 squats while purposefully displacing the knee anteriorly (AP malaligned), 5 squats while purposefully displacing the knee medially (ML malaligned) and 5 squats with control alignment (control). Normalized EMG data (MVIC) were reduced to 100 points and represented as percentage of squat cycle with 50% representing peak knee flexion and 0 and 99% representing fully extended. Vastus lateralis, medialis, and rectus femoris activity decreased in the medio-lateral (ML) malaligned squat compared with the control squat. In the antero-posterior (AP) malaligned squat, the vastus lateralis, medialis, and rectus femoris activity decreased during initial descent and final ascent; however, vastus lateralis and rectus femoris activation increased during initial ascent compared with the control squat. The biceps femoris and gastrocnemius displayed increased activation during both malaligned squats compared with the control squat. In conclusion, participants had altered muscle activation patterns during squats with intentional frontal and sagittal malalignment as demonstrated by changes in quadriceps, biceps femoris, and gastrocnemius activation during the squat cycle.

  14. Core decompression or quadratus femoris muscle pedicle bone grafting for nontraumatic osteonecrosis of the femoral head: A randomized control study

    PubMed Central

    Li, Deqiang; Li, Ming; Liu, Peilai; Zhang, Yuankai; Ma, Liang; Xu, Fei

    2016-01-01

    Background: The traditional management for osteonecrosis of the femoral head (ONFH) includes core decompression (CD) and quadratus femoris muscle pedicle bone graft (QF-MPBG). The aim of this study was to investigate the effects of CD and QF-MPBG on the patients with nontraumatic ONFH in an early stage. Materials and Methods: 39 patients (47 hips) with ONFH in an early stage (Ficat Stage I or II) were randomly divided into two groups according to random number table method. One group was treated with CD and cancellous bone grafting. Another group was treated QF-MPBG with cancellous bone grafting. The hip function was evaluated using Harris hip score (HHS). The repair of the femoral head was estimated through X-ray, computed tomography (CT), or magnetic resonance imaging (MRI). The surgical time and intraoperative blood loss was calculated. Results: All patients were followed for an average 2.5 years (range from 1.5 to 4 years). Two hips in CD group progressed into stage 3 and three hips in QF-MPBG group processed into stage 3. No patient accepted the THA at the last followup. The HHSs significantly increased in both groups after surgery (P < 0.05). No statistical differences were found between CD and QF-MPBG groups in postoperative HHSs at last followup (P > 0.05). X-ray and CT showed that the femoral head did not progress to collapse after operation in both groups. In addition, MRI showed that the edema signals decreased. However, the surgical time was longer in QF-MPBG group than that in CD group (P < 0.05). The intraoperative blood loss was more in QF-MPBG than that in CD group (P < 0.05). Conclusion: The CD with bone graft could relieve hip pain, improve hip function with much lesser surgical trauma compared to QF-MPBG. Hence, the CD with bone graft should be generally used for the treatment of patients with an early stage (Ficat Stage I or II) ONFH. PMID:27904218

  15. Biomechanical characteristics of skeletal muscles and associations between running speed and contraction time in 8- to 13-year-old children.

    PubMed

    Završnik, Jernej; Pišot, Rado; Šimunič, Boštjan; Kokol, Peter; Blažun Vošner, Helena

    2017-02-01

    Objective To investigate associations between running speeds and contraction times in 8- to 13-year-old children. Method This longitudinal study analyzed tensiomyographic measurements of vastus lateralis and biceps femoris muscles' contraction times and maximum running speeds in 107 children (53 boys, 54 girls). Data were evaluated using multiple correspondence analysis. Results A gender difference existed between the vastus lateralis contraction times and running speeds. The running speed was less dependent on vastus lateralis contraction times in boys than in girls. Analysis of biceps femoris contraction times and running speeds revealed that running speeds of boys were much more structurally associated with contraction times than those of girls, for whom the association seemed chaotic. Conclusion Joint category plots showed that contraction times of biceps femoris were associated much more closely with running speed than those of the vastus lateralis muscle. These results provide insight into a new dimension of children's development.

  16. Muscle activity in the lower limbs during push-down movement with a new active-exercise apparatus for the leg

    PubMed Central

    Tanaka, Kenta; Kamada, Hiroshi; Shimizu, Yukiyo; Aikawa, Shizu; Irie, Shun; Ochiai, Naoyuki; Sakane, Masataka; Yamazaki, Masashi

    2016-01-01

    [Purpose] Lower-limb deep vein thrombosis is a complication of orthopedic surgery. A leg-exercise apparatus named “LEX” was developed as a novel active-exercise apparatus for deep vein thrombosis prevention. Muscle activity was evaluated to assess the effectiveness of exercise with LEX in the prevention. [Subjects] Eight healthy volunteers participated in this study. [Methods] Muscle activities were determined through electromyography during exercise with LEX [LEX (+)] and during active ankle movements [LEX (−)]. The end points were peak % maximum voluntary contraction and % integrated electromyogram of rectus femoris, vastus lateralis, biceps femoris, tibialis anterior, gastrocnemius, and soleus. [Results] LEX (+) resulted in higher average values in all muscles except the tibialis anterior. Significant differences were noted in the peak of the biceps femoris and gastrocnemius and in the integrated electromyogram of the rectus femoris, vastus lateralis, gastrocnemius, and soleus. The LEX (+)/LEX (−) ratio of the peak was 2.2 for the biceps femoris and 2.0 for the gastrocnemius . The integrated electromyogram was 1.8 for the gastrocnemius, 1.5 for the rectus femoris, 1.4 for the vastus lateralis, and 1.2 for the soleus. [Conclusion] Higher muscle activity was observed with LEX (+). LEX might be a good tool for increasing lower-limb blood flow and deep vein thrombosis prevention. PMID:27134410

  17. Immediate effects of acupuncture on biceps brachii muscle function in healthy and post-stroke subjects

    PubMed Central

    2012-01-01

    Background The effects of acupuncture on muscle function in healthy subjects are contradictory and cannot be extrapolated to post-stroke patients. This study evaluated the immediate effects of manual acupuncture on myoelectric activity and isometric force in healthy and post-stroke patients. Methods A randomized clinical trial, with parallel groups, single-blinded study design, was conducted with 32 healthy subjects and 15 post-stroke patients with chronic hemiparesis. Surface electromyography from biceps brachii during maximal isometric voluntary tests was performed before and after 20-min intermittent, and manual stimulation of acupoints Quchi (LI11) or Tianquan (PC2). Pattern differentiation was performed by an automated method based on logistic regression equations. Results Healthy subjects showed a decrease in the root mean-squared (RMS) values after the stimulation of LI11 (pre: 1.392 ± 0.826 V; post: 0.612 ± 0.0.320 V; P = 0.002) and PC2 (pre: 1.494 ± 0.826 V; post: 0.623 ± 0.320 V; P = 0.001). Elbow flexion maximal isometric voluntary contraction (MIVC) was not significantly different after acupuncture stimulation of LI11 (pre: 22.2 ± 10.7 kg; post: 21.7 ± 9.5 kg; P = 0.288) or PC2 (pre: 18.8 ± 4.6 kg; post: 18.7 ± 6.0 kg; P = 0.468). Post-stroke patients did not exhibit any significant decrease in the RMS values after the stimulation of LI11 (pre: 0.627 ± 0.335 V; post: 0.530 ± 0.272 V; P = 0.187) and PC2 (pre: 0.601 ± 0.258 V; post: 0.591 ± 0.326 V; P = 0.398). Also, no significant decrease in the MIVC value was observed after the stimulation of LI11 (pre: 9.6 ± 3.9 kg; post: 9.6 ± 4.7 kg; P = 0.499) or PC2 (pre: 10.7 ± 5.6 kg; post: 10.2 ± 5.3 kg; P = 0.251). Different frequency of patterns was observed among healthy subjects and post-stroke patients groups (χ2 = 9.759; P = 0.021). Conclusion Manual acupuncture provides sufficient neuromuscular stimuli to promote immediate changes in motor unit gross recruitment without repercussion in

  18. Driving Sodium-Potassium Pumps With An Oscillating Electric Field: Effects On Muscle Recovery In The Human Biceps Brachii

    NASA Astrophysics Data System (ADS)

    Bovyn, Matt; Chen, Wei; Lanes, Olivia; Mast, Jason

    2013-03-01

    Dr. Chen has developed a technique called synchronization modulation, which uses an oscillating electric field to increase the rate at which the sodium-potassium pumps in the cell membrane work. Because the sodium-potassium pump is integral in the recovery of skeletal muscle fibers after an action potential, we investigated the effects of applying synchronization modulation to muscles which had already undergone fatigue due to repeated action potentials during exercise. Fatigue was induced in human subjects' biceps brachii through isometric contraction. Surface electromyography measurements of fatigue index were used to quantify how the muscle recovered over the minutes following fatigue, both when synchronization modulation was applied and when it was absent. The preliminary results were inconclusive, but it is hoped that in later work it will be shown that applying synchronization modulation is effective in increasing the rate at which the muscle recovers to its initial state. This would demonstrate not only that synchronization modulation can be successfully applied to human muscle, but also that it has many potential applications in sports medicine and novel disease treatments. Work done as part of an REU program at the University of South Florida

  19. Facilitation and habituation of the startle reflex over the tonically active biceps brachii muscle contralateral to electrical stimuli.

    PubMed

    Alaid, Ssuhir; Tyagi, Indu; Kornhuber, Malte

    2012-10-03

    The aim of the present investigation was to explore the impact of muscle contraction on startle reflex responses after electrical stimuli (single or trains of 3) and to study startle reflex habituation. The electromyogram was recorded over the tonically active biceps brachii muscle in 19 healthy subjects contralateral to electrical stimuli (9-12mA) that were delivered at 1.0 and 0.4Hz over the superficial radial nerve. The muscle contraction level was varied by loading weight on the subject's bent arm (0.0, 1.0 or 1.5kg). Furthermore, short term reflex habituation was investigated using 30 blocks of 5 subsequent stimuli. Startle response amplitudes gained significantly (p<0.05) after (i) train stimuli as compared with single stimuli, during (ii) high versus low levels of muscle contraction, and at (iii) 0.4Hz versus 1.0Hz stimuli. Startle reflex amplitudes decreased significantly by the influence of preceding stimuli (p<0.05). This study provides evidence that the startle reflex can be significantly influenced by weight load, i.e. by volitional influences. Startle reflex investigation over a contracted limb muscle results in a high probability of startle release and thereby improved detection of SR habituation following preceding stimuli.

  20. Multiple muscular variations including tenuissimus and tensor fasciae suralis muscles in the posterior thigh of a human case.

    PubMed

    Arakawa, Takamitsu; Kondo, Takahiro; Tsutsumi, Masahiro; Watanabe, Yuko; Terashima, Toshio; Miki, Akinori

    2017-03-07

    The posterior thigh muscles on the right side of an 81-year-old male cadaver had multiple variations, denoted muscles I-IV. Muscle I originated from the posteromedial surface of the greater trochanter and divided into two muscle bellies. These muscle bellies fused with the long head of the biceps femoris and were innervated by two branches from muscular branches of the semitendinosus and the long head of the biceps. Muscle II separated from the medial surface of the long head of the biceps in the proximal third and fused with the semitendinosus in the distal fourth. Muscle III was a biventer muscle. Its superior belly separated from the medial surface of the long head of the biceps in the distal third. The inferior belly of this muscle fused with the posterior surface of the crural fascia and was innervated by the tibial nerve. Muscle IV separated from the adductor magnus muscle, passed between the long and short heads of the biceps, fused with the inferior belly of muscle III, and was innervated by the muscular branch of the common fibular nerve to the short head of the biceps. Peeling off the epineurium of the muscular branches to the inferior belly of muscle III showed that this nerve fascicle divided from the common trunk with branches to the gastrocnemius and soleus muscles. The inferior bellies of muscle III and muscle IV were thought to be equivalent to the tensor fasciae suralis and tenuissimus muscles, respectively.

  1. The dependence between clinical condition and value of the maximum force in the quadriceps femoris muscle during MVC test in patients with knee osteoarthritis.

    PubMed

    Nowak, Karina; Sobota, Grzegorz; Bacik, Bogdan; Hajduk, Grzegorz; Kusz, Damian

    2012-01-01

    The aim of this study was to check whether there was a correlation between the value of the maximum developed torque of the quadriceps femoris muscle and subjective evaluation of a patient's pain which is measured by the VAS. Also evaluated were changes in the muscle torque value and KSS scale over time. For examining patient's condition use was made of a KSS scale (knee score: pain, range of motion, stability of joint and limb axis) before the surgery and in weeks 6 and 12, as well as 6 months after surgery. It was found to be constantly improving in comparison with the condition before the surgery. This is confirmed by a significant statistical value difference of KSS scale. The surgery substantially increases the quality of live and function recurrence.

  2. Gene expression pattern of glucose transporters in the skeletal muscles of newly hatched chicks.

    PubMed

    Shimamoto, Saki; Ijiri, Daichi; Kawaguchi, Mana; Nakashima, Kazuki; Ohtsuka, Akira

    2016-07-01

    The gene expression pattern of the glucose transporters (GLUT1, GLUT3, GLUT8, and GLUT12) among pectoralis major and minor, biceps femoris, and sartorius muscles from newly hatched chicks was examined. GLUT1 mRNA level was higher in pectoralis major muscle than in the other muscles. Phosphorylated AKT level was also high in the same muscle, suggesting a relationship between AKT and GLUT1 expression.

  3. Impact of decline-board squat exercises and knee joint angles on the muscle activity of the lower limbs.

    PubMed

    Lee, Daehee; Lee, Sangyong; Park, Jungseo

    2015-08-01

    [Purpose] This study aims to investigate how squat exercises on a decline board and how the knee joint angles affect the muscle activity of the lower limbs. [Subjects] The subjects were 26 normal adults. [Methods] A Tumble Forms wedge device was used as the decline board, and the knee joint angles were measured with a goniometer. To examine the muscle activity of the biceps femoris, rectus femoris, gastrocnemius lateralis, and tibialis anterior of the lower limbs, a comparison analysis with electromyography was conducted. [Results] The muscle activity of the biceps femoris, rectus femoris, gastrocnemius lateralis, and tibialis anterior increased with increased knee joint angles, both for squat exercises on the decline board and on a flat floor. When the knee joint angle was 45°, 60°, and 90°, the muscle activity of the rectus femoris was significantly higher and that of the tibialis anterior was significantly lower during squat exercises on the decline board than on the flat floor. When the knee joint angle was 90°, the muscle activity of the gastrocnemius lateralis was significantly lower. [Conclusion] Squat exercises on a decline board are an effective intervention to increase the muscle activity of the rectus femoris with increased knee joint angles.

  4. Open subpectoral biceps tenodesis: reliable treatment for all biceps tendon pathology.

    PubMed

    Kane, Patrick; Hsaio, Philip; Tucker, Bradford; Freedman, Kevin B

    2015-01-01

    Long head of the biceps (LHB) tendon pathology is a common cause of pain in the shoulder. Pathology encountered includes biceps tendon tears and tendonitis, biceps anchor or superior labral tears, and biceps subluxation or instability. Current surgical treatment options for LHB disorders include tenotomy and tenodesis. Tenodesis prevents cosmetic deformity and biceps cramping with activity. Open subpectoral tenodesis anatomically restores the length-tension relationship of the biceps muscle and removes all diseased biceps from the bicipital groove. The authors present their technique of open subpectoral tenodesis, which demonstrates a high success rate with consistent pain relief and dependable fixation.

  5. The growth patterns of three hindlimb muscles in the chicken.

    PubMed Central

    Helmi, C; Cracraft, J

    1977-01-01

    This study was designed to investigate the growth patterns of three hindlimb muscles of the chicken relative to the functional-biomechanical demands of increasing body size. The biceps femoris, a bipennate non-postural muscle, grew relatively faster in terms of wet and dry weight than did the parallel-fibred adductor superficialis or the unipennate adductor profundus, both postural muscles. All three muscles exhibited positive allometry (relative to body weight) in muscle length but only biceps femoris and adductor profundus showed positive allometry in cross sectional area adductor superficialis having isometric growth in this parameter. In biceps femoris and adductor superficialis the lengths of the longest and shortest fasciculi grew at equal rates, whereas in adductor profundus the shortest fasciculi grew faster than the longest. We conclude that muscle weight alone is an insufficient indicator of changing function in growing muscle. Hence, growth studies should include other functionally relevant parameters such as cross sectional area, which is proportional to the force-producing capabilities of the muscle, or fibre (fasciculus) length, which is indicative of the absolute amount of stretching or shortening that is possible and of the contraction velocity. PMID:885779

  6. Changes in cortical beta activity related to a biceps brachii movement task while experiencing exercise induced muscle damage.

    PubMed

    Plattner, Kristina; Lambert, Michael I; Tam, Nicholas; Lamberts, Robert P; Baumeister, Jochen

    2014-01-17

    Exercise-induced-muscle-damage (EIMD) is a well-described phenomenon which leads to decreased force output and altered neuromuscular function. How these symptoms of EIMD affect brain function, in particular cortical activity has not been described. Therefore the aim of this study was to investigate the relationship between the symptoms of EIMD and cortical beta (β) activity during a submaximal biceps brachii movement. Half of the subjects participated in an EIMD protocol. Control and EIMD groups were monitored for 132h thereafter. Muscle pain scores in the EIMD group peaked after 36h with the lowest muscle torque reported at 12h. Beta-1 and -2 activity was increased in the frontal and parietal area in the experimental group at 12h. This suggests an impact of EIMD induced neuromuscular changes on the cortical proprioceptive and motor perceptive networks. Beta-2 activity decreased in the control group over time suggesting a loss in focused attention and greater familiarization with the protocol as the study progressed. These data suggest that a change in β-1 and -2 activity is associated with integrating movement perception and proprioception post-EIMD.

  7. The effect of temperature on proliferation and differentiation of chicken skeletal muscle satellite cells isolated from different muscle types.

    PubMed

    Harding, Rachel L; Halevy, Orna; Yahav, Shlomo; Velleman, Sandra G

    2016-04-01

    Skeletal muscle satellite cells are a muscle stem cell population that mediate posthatch muscle growth and repair. Satellite cells respond differentially to environmental stimuli based upon their fiber-type of origin. The objective of this study was to determine how temperatures below and above the in vitro control of 38°C affected the proliferation and differentiation of satellite cells isolated from the chicken anaerobic pectoralis major (p. major) or mixed fiber biceps femoris (b.femoris) muscles. The satellite cells isolated from the p. major muscle were more sensitive to both cold and hot temperatures compared to the b.femoris satellite cells during both proliferation and differentiation. The expressions of myogenic regulatory transcription factors were also different between satellite cells from different fiber types. MyoD expression, which partially regulates proliferation, was generally expressed at higher levels in p. major satellite cells compared to the b.femoris satellite cells from 33 to 43°C during proliferation and differentiation. Similarly, myogenin expression, which is required for differentiation, was also expressed at higher levels in p. major satellite cells in response to both cold and hot temperatures during proliferation and differentiation than b. femoris satellite cells. These data demonstrate that satellite cells from the anaerobic p. major muscle are more sensitive than satellite cells from the aerobic b. femoris muscle to both hot and cold thermal stress during myogenic proliferation and differentiation.

  8. [Bursitis with severe tendon and muscle necrosis on the lateral stifle area in cattle].

    PubMed

    Nuss, K; Räber, M; Sydler, T; Muggli, E; Hässig, M; Guscetti, F

    2011-11-01

    In 21 animals, chronic swelling on the lateral aspect of the stifle also known as «perigonitis», «stable-syndrome» or «bursitis bicipitalis femoris» were evaluated. Ultrasonography showed increased fluid in the distal subtendinous bursa of the biceps femoris muscle and structural changes in the tendons, muscles, subcutis and fasciae. Soft tissue swelling and an irregular contour of the lateral tibial condyle were typical signs on radiographs. Macroscopic changes were found at the insertion of the biceps femoris muscle, the distal subtendinous bursa of the biceps femoris muscle, the lateral collateral ligament of the stifle, the origin of muscles on the lateral femoral condyle and the lateral tibial condyle. They mainly consisted of tendon and muscle tissue necrosis with granulation tissue. Histology revealed areas of coagulation necrosis in tendons and ligaments, in which occasionally Onchocerca spp. were seen. The severity of lesions correlated well with the clinical signs, which were associated with a poor prognosis in advanced cases.

  9. MUSCLE TRANSFER FROM TRICEPS TO BICEPS IN PATIENTS WITH CHRONIC INJURY OF THE UPPER TRUNK OF THE BRACHIAL PLEXUS

    PubMed Central

    Souza, Fabiano Inúcio de; Saito, Mateus; Kimura, Luiz Koiti; Júnior, Rames Mattar; Zumiotti, Arnaldo Valdir

    2015-01-01

    Objective: To evaluate the results from transposition of the triceps for elbow flexion in patients with chronic and complete injury to the upper trunk of the brachial plexus. Methods: This was a retrospective study, including only patients who had biceps grade 0 and triceps grade 5, who underwent anterior transfer of the triceps muscle, performed between 1998 and 2005. The affected side, sex, type of accident, strength of elbow flexion, complications and patient satisfaction were investigated in 11 cases. Results: 10 patients were male; the age range was from 24 to 49 years, with a mean of 33.7 years. The minimum time between injury and surgery was 21 months (range 21-74 months). The left side was affected in eight cases, and the right only in three. Good results were obtained in 10 patients, who acquired elbow flexion strength of grade 3 (two cases) and grade 4 (eight cases), while one evolved unfavorably with grade 2 strength. Two cases had complications (initial compartment syndrome and insufficient tensioning). All the patients said that they were satisfied with the procedure. Conclusion: Anterior transposition of the triceps muscle provided patient satisfaction in all cases except one, attaining strength grade 4 in eight cases, grade 3 in two cases and grade 2 in one case. PMID:27022572

  10. Analysis of concentric and eccentric contractions in biceps brachii muscles using surface electromyography signals and multifractal analysis.

    PubMed

    Marri, Kiran; Swaminathan, Ramakrishnan

    2016-06-23

    Muscle contractions can be categorized into isometric, isotonic (concentric and eccentric) and isokinetic contractions. The eccentric contractions are very effective for promoting muscle hypertrophy and produce larger forces when compared to the concentric or isometric contractions. Surface electromyography signals are widely used for analyzing muscle activities. These signals are nonstationary, nonlinear and exhibit self-similar multifractal behavior. The research on surface electromyography signals using multifractal analysis is not well established for concentric and eccentric contractions. In this study, an attempt has been made to analyze the concentric and eccentric contractions associated with biceps brachii muscles using surface electromyography signals and multifractal detrended moving average algorithm. Surface electromyography signals were recorded from 20 healthy individuals while performing a single curl exercise. The preprocessed signals were divided into concentric and eccentric cycles and in turn divided into phases based on range of motion: lower (0°-90°) and upper (>90°). The segments of surface electromyography signal were subjected to multifractal detrended moving average algorithm, and multifractal features such as strength of multifractality, peak exponent value, maximum exponent and exponent index were extracted in addition to conventional linear features such as root mean square and median frequency. The results show that surface electromyography signals exhibit multifractal behavior in both concentric and eccentric cycles. The mean strength of multifractality increased by 15% in eccentric contraction compared to concentric contraction. The lowest and highest exponent index values are observed in the upper concentric and lower eccentric contractions, respectively. The multifractal features are observed to be helpful in differentiating surface electromyography signals along the range of motion as compared to root mean square and median

  11. Activation of back and lower limb muscles during squat exercises with different trunk flexion

    PubMed Central

    Lee, Tae-Sik; Song, Min-Young; Kwon, Yu-Jeong

    2016-01-01

    [Purpose] The purpose of this study was to investigate the activation of back and lower limb muscles in subjects who were performing a squat exercise at different angles of trunk flexion. [Subjects and Methods] Twenty healthy subjects (age 21.1± 1.8 years, height 168.7 ± 8.2 cm, weight 66.1 ± 12.3 kg) volunteered. The activation of the erector spinae muscle, rectus femoris muscle, gluteus maximus muscle and biceps femoris muscle was observed while the subjects performed squat exercises with a trunk flexion of 0°, 15°, and 30°. [Results] The erector spinae muscle, gluteus maximus muscle, and biceps femoris muscle were activated more during the squat exercise with the trunk flexion at 30° than the exercise with the trunk flexion at 0°. The rectus femoris muscle showed a tendency to decrease as the truck flexion increased. [Conclusion] Squat exercise be executed while maintaining an erect trunk posture if one wishes to strengthen the quadriceps muscle while reducing the load on the lower back. PMID:28174462

  12. Activation of back and lower limb muscles during squat exercises with different trunk flexion.

    PubMed

    Lee, Tae-Sik; Song, Min-Young; Kwon, Yu-Jeong

    2016-12-01

    [Purpose] The purpose of this study was to investigate the activation of back and lower limb muscles in subjects who were performing a squat exercise at different angles of trunk flexion. [Subjects and Methods] Twenty healthy subjects (age 21.1± 1.8 years, height 168.7 ± 8.2 cm, weight 66.1 ± 12.3 kg) volunteered. The activation of the erector spinae muscle, rectus femoris muscle, gluteus maximus muscle and biceps femoris muscle was observed while the subjects performed squat exercises with a trunk flexion of 0°, 15°, and 30°. [Results] The erector spinae muscle, gluteus maximus muscle, and biceps femoris muscle were activated more during the squat exercise with the trunk flexion at 30° than the exercise with the trunk flexion at 0°. The rectus femoris muscle showed a tendency to decrease as the truck flexion increased. [Conclusion] Squat exercise be executed while maintaining an erect trunk posture if one wishes to strengthen the quadriceps muscle while reducing the load on the lower back.

  13. The temporal relationship of thresholds between muscle activity and ventilation during bicycle ramp exercise in community dwelling elderly males

    PubMed Central

    Sasaki, Kentaro; Kimura, Tsuyoshi; Kojima, Satoshi; Higuchi, Hiroyuki

    2016-01-01

    [Purpose] To compare the appearance time of the ventilatory threshold point and the electromyographic threshold in the activity of the vastus lateralis, rectus femoris, biceps femoris long head and gastrocnemius lateral head muscles during ramp cycling exercise in elderly males. [Subjects and Methods] Eleven community dwelling elderly males participated in this study. Subjects performed exercise testing with an expiratory gas analyzer and surface electromyography to evaluate the tested muscle activities during ramp exercise. [Results] The electromyographic threshold for rectus femoris was not valid because the slope after electromyographic threshold was not significant as compared to that before electromyographic threshold. The slope of the regression line for vastus lateralis was significantly decreased after electromyographic threshold while biceps femoris and gastrocnemius were increased. The electromyographic threshold appearance times for vastus lateralis and gastrocnemius were significantly earlier than ventilatory threshold point. There were no difference in electromyographic threshold appearance times among three muscles. [Conclusion] These results suggest that the increase in the slope of the regression line after electromyographic threshold for vastus lateralis was decreased, possibly indicating to postpone muscular fatigue resulting from the activation of biceps femoris and gastrocnemius as biarticular antagonists. This recruitment pattern might be an elderly-specific strategy. PMID:27942152

  14. [Amino acid composition of the rat quadriceps femoris muscle after a flight on the Kosmos-936 biosatellite].

    PubMed

    Vlasova, T F; Miroshnikova, E B; Poliakov, V V; Murugova, T P

    1982-01-01

    The amino acid composition of the quadriceps muscle of rats flown onboard the biosatellite Cosmos-936 and exposed to the ground-based synchronous control experiment was studied. The weightless rats showed changes in the amino acid concentration in the quadriceps muscle. The centrifuged flight and synchronous rats displayed an accumulation of free amino acids in the above muscle.

  15. Lower extremity muscles activity in standing and sitting position with use of sEMG in patients suffering from Charcot-Marie-Tooth syndrome.

    PubMed

    Kuciel, Natalia Maria; Konieczny, Grzegorz Krzysztof; Oleksy, Łukasz; Wrzosek, Zdzisława

    2016-01-01

    There is very limited, evidenced data about movement possibilities in patients with high level of lower limb muscles atrophy and fatigue in patients suffering from Charcot-Marie-Tooth syndrome. Patient (age 46) suffering from Charcot-Marie-Tooth disease for 30 years with multiple movement restrictions and muscles atrophy above knees took part into the study. Tests were performed for 8 muscles of the lower limb and pelvis. Muscles electrical activity was tested in sitting and standing position (for knees extended and hyperextended). In the right leg rectus femoris, vastus lateralis obliquus, gluteus medius and semitendinosus muscles activated at first and were working the longest time. The highest activity was observed in standing position with knees extended. In the left leg rectus femoris and biceps femoris muscles activated at first and biceps femoris was working the longest time. Activity level in left lower limb is much lower than in the right one. Muscles weakness is asymmetric. Left leg is much weaker and engages antagonists and synergists muscles to compensate weaker rectus femoris, vastus medialis obliquus and vastus lateralis obliquus.

  16. mRNA expression characteristics are different in irreversibly atrophic intrinsic muscles of the forepaw compared with reversibly atrophic biceps in a rat model of obstetric brachial plexus palsy (OBPP).

    PubMed

    Wu, Ji-Xin; Chen, Liang; Ding, Fei; Chen, Le-Zi; Gu, Yu-Dong

    2016-04-01

    In obstetric brachial plexus palsy (OBPP), irreversible muscle atrophy occurs much faster in intrinsic muscles of the hand than in the biceps. To elucidate the mechanisms involved, mRNA expression profiles of denervated intrinsic muscles of the forepaw (IMF) and denervated biceps were determined by microarray using the rat model of OBPP where atrophy of IMF is irreversible while atrophy of biceps is reversible. Relative to contralateral control, 446 dysregulated mRNAs were detected in denervated IMF and mapped to 51 KEGG pathways, and 830 dysregulated mRNAs were detected in denervated biceps and mapped to 52 KEGG pathways. In denervated IMF, 10 of the pathways were related to muscle regulation; six with down-regulated and one with up-regulated mRNAs. The remaining three pathways had both up- and down-regulated mRNAs. In denervated biceps, 13 of the pathways were related to muscle regulation, six with up-regulated and seven with down-regulated mRNAs. Five of the pathways with up-regulated mRNAs were related to regrowth and differentiation of muscle cells. Among the 23 pathways with dysregulated mRNAs, 13 were involved in regulation of neuromuscular junctions. Our results demonstrated that mRNAs expression characteristics in irreversibly atrophic denervated IMF were different from those in reversibly atrophic denervated biceps; dysregulated mRNAs in IMF were associated with inactive pathways of muscle regulation, and in biceps they were associated with active pathways of regrowth and differentiation. Lack of self-repair potential in IMF may be a major reason why atrophy of IMF becomes irreversible much faster than atrophy of biceps after denervation.

  17. Effects of forward trunk lean on hamstring muscle kinematics during sprinting.

    PubMed

    Higashihara, Ayako; Nagano, Yasuharu; Takahashi, Kazumasa; Fukubayashi, Toru

    2015-01-01

    This study aimed to investigate the effects of forward trunk lean on hamstring muscle kinematics during sprinting. Eight male sprinters performed maximal-effort sprints in two trunk positions: forward lean and upright. A three-dimensional musculoskeletal model was used to compute the musculotendon lengths and velocity of the biceps femoris long head, semitendinosus, and semimembranosus muscles during the sprinting gait cycle. The musculotendon lengths of all the three hamstring muscles at foot strike and toe-off were significantly greater during the forward trunk lean sprint than during the upright trunk sprint. In addition, a positive peak musculotendon lengthening velocity was observed in the biceps femoris long head and semimembranosus muscles during the late stance phase, and musculotendon lengths at that instant were significantly greater during the forward trunk lean sprint than during the upright trunk sprint. The present study provides significant evidence that a potential for hamstring muscle strain injury involving forward trunk lean sprinting would exist during the stance phase. The results also indicate that the biceps femoris long head and semimembranosus muscles are stretched during forward trunk lean sprinting while contracting eccentrically in the late stance phase; thus, the elongation load on these muscles could be increased.

  18. Comparison of hamstring muscle behavior for anterior cruciate ligament (ACL) patient and normal subject during local marching

    NASA Astrophysics Data System (ADS)

    Amineldin@Aminudin, Nurul Izzaty Bt.; Rambely, A. S.

    2014-09-01

    This study aims to investigate the hamstring muscle activity after the surgery by carrying out an electromyography experiment on the hamstring and to compare the behavior of the ACL muscle activity between ACL patient and control subject. Electromyography (EMG) is used to study the behavior of muscles during walking activity. Two hamstring muscles involved which are semitendinosus and bicep femoris. The EMG data for both muscles were recorded while the subject did maximum voluntary contraction (MVC) and marching. The study concluded that there were similarities between bicep femoris of the ACL and control subjects. The analysis showed that the biceps femoris muscle of the ACL subject had no abnormality and the pattern is as normal as the control subject. However, ACL patient has poor semitendinosus muscle strength compared to that of control subject because the differences of the forces produced. The force of semitendinosus value for control subject was two times greater than that of the ACL subject as the right semitendinosus muscle of ACL subject was used to replace the anterior cruciate ligament (ACL) that was injured.

  19. Bilateral asymmetric supernumerary heads of biceps brachii

    PubMed Central

    Lee, Song Eun; Jung, Chaeyong; Ahn, Kyu Youn

    2011-01-01

    Anatomical variations of the biceps brachii have been described by various authors, but the occurrence of bilateral asymmetric supernumerary heads is rare and has not been reported. We found three accessory heads of the biceps brachii muscle on right arm and an anomalous third head of biceps brachii on left arm. The third, fourth, and fifth heads of right arm originated from the body of humerus at the insertion site of coracobrachialis and inserted into the distal part of biceps brachii short head in order. The third head of left arm originated from humerus at the insertion site of coracobrachialis and combined with the distal part of biceps brachii and continued to the proximal part of common biceps tendon. Understanding the existence of bilateral asymmetric supernumerary heads of biceps brachii may influence preoperative diagnosis and surgery on the upper limbs. PMID:22025976

  20. Effects of Exposure to Normobaric Hyperoxia on the Recovery of Local Muscle Fatigue in the Quadriceps Femoris of Young People

    PubMed Central

    Yokoi, Yuka; Yanagihashi, Ryuya; Morishita, Katsuyuki; Fujiwara, Takayuki; Abe, Koji

    2014-01-01

    [Purpose] Acute development of local muscle fatigue and recovery often become large issues on sports fields. This study aimed to identify the effects of normobaric hyperoxia on the recovery of local muscle fatigue. [Subjects] Eleven healthy males participated in this study, and they all completed two protocols in a random order. [Methods] Subjects performed single-leg isometric knee extension at 70% of their maximum voluntary isometric contraction (MVIC) for as long as possible. Each participant was subsequently treated with one of two recovery conditions: 20.9% O2 or 30.0% O2 for 30 minutes. Afterwards, they performed an identical isometric task to measure the extent of their recovery. The following parameters were used to assess the degrees of muscle fatigue: MVIC, endurance time, surface electromyography (sEMG) power spectra, and changes in hemoglobin concentration using near-infrared spectroscopy (NIRS). [Results] The treatment of 30.0% O2 induced a significant recovery rate in MVIC compared to the 20.9% O2. Additionally, the data revealed a significantly higher concentration of total hemoglobin after the 30.0% O2 treatment than after the 20.9% O2 treatment. [Conclusion] The results of this study suggest that recovery from acute muscle fatigue can be better facilitated under 30.0% normobaric hyperoxia than a normoxic condition. Therefore, for cases requiring quicker full recovery, treatment under 30.0% O2 environment for 30 minutes is recommended. PMID:24707107

  1. Functional transposition of the latissimus dorsi muscle for biceps reconstruction after upper arm replantation.

    PubMed

    Schoeller, Thomas; Wechselberger, Gottfried; Hussl, Heribert; Huemer, Georg M

    2007-01-01

    Major upper arm amputations are often accompanied by different levels of soft-tissue divisions involving crushing, traction, and avulsion injuries to various structures. In these cases the goal is not only the re-establishment of circulation, but also functional outcome. Some patients require further reconstruction for functional restoration of elbow flexion and additional soft tissue coverage. Five patients underwent functional latissimus dorsi transfer for restoration of elbow flexion after successful upper arm replantation at our institution. The transfer was unipolar in four patients and bipolar in one. The patients' ages ranged from seven to 55 years. The time period between replantation and transfer ranged from two weeks to 12 months. All flaps healed well with minimal donor site morbidity. At mean 43-month follow-up (range: 22-65 months), functional results were good with M4 in three patients and M3 in two patients for elbow flexion. The pedicled latissimus dorsi muscle flap is a valuable tool to restore elbow flexion and provide coverage of soft tissue defects after major upper arm replantations.

  2. Rupture of the distal biceps brachii tendon: isokinetic power analysis and complications after anatomic reinsertion compared with fixation to the brachialis muscle.

    PubMed

    Klonz, Andreas; Loitz, Dietmar; Wöhler, Peter; Reilmann, Heinrich

    2003-01-01

    Anatomic reattachment of the distal biceps tendon is well established but bears the risk of complications including loss of motion and nerve damage. We questioned whether nonanatomic repair by tenodesis to the brachialis muscle is able to accomplish similar results with less risk. We compared the results of anatomic repair with suture anchors (n = 6) with the results of nonanatomic repair (n = 8). Anatomic reattachment of the biceps tendon can restore full power of flexion in most cases as determined by isokinetic muscle tests (mean, 96.8% compared with the contralateral side). Nonanatomic repair also restores flexion strength to a mean of 96%. Supination power averaged 91% after anatomic repair. Supination strength after nonanatomic repair did not improve in 4 of 8 patients (42%-56% of the uninjured arm). The other 4 patients were able to produce 80% to 150% of the strength of the contralateral side. Major complications such as radioulnar synostosis or motor nerve damage were not encountered in either group. Heterotopic ossification was seen in 4 cases after reinsertion to the tuberosity. One of these patients was not satisfied with the procedure because of anterior elbow pain, even at rest. After tenodesis to the brachialis, one patient was unsatisfied because of considerable weakness. We concluded that major complications after anatomic repair are rare but must not be ignored. Tenodesis of the distal biceps tendon is a safe alternative procedure. We inform our patients about the benefits and risks of anatomic and nonanatomic repair as well as those of nonoperative treatment. The decision concerning the type of therapy best suited for an individual patient should be made on an informed consent basis.

  3. Muscular activity of lower limb muscles associated with working on inclined surfaces

    PubMed Central

    Lu, Ming-Lun; Kincl, Laurel; Lowe, Brian; Succop, Paul; Bhattacharya, Amit

    2015-01-01

    This study investigated effects of visual cues, muscular fatigue, task performance and experience of working on inclined surfaces on activity of postural muscles in the lower limbs associated with maintaining balance on three inclined surfaces—0°, 14° and 26°. Normalized electromyographic (NEMG) data were collected on 44 professional roofers bilaterally from the rectus femoris, biceps femoris, tibialii anterior, and gastrocnemii medial muscle groups. The 50th and 95th percentile normalized EMG amplitudes were used as EMG variables. Results showed that inclination angle and task performance caused a significant increase in the NEMG amplitudes of all postural muscles. Visual cues were significantly associated with a decrease in the 95th percentile EMG amplitude for the right gastrocnemius medial and tibialis anterior. Fatigue was related to a significant decrease in the NEMG amplitude for the rectus femoris. Experience of working on inclined surfaces did not have a significant effect on the NEMG amplitude. PMID:25331562

  4. Influence of pelvis position on the activation of abdominal and hip flexor muscles.

    PubMed

    Workman, J Chad; Docherty, David; Parfrey, Kevin C; Behm, David G

    2008-09-01

    A pelvic position has been sought that optimizes abdominal muscle activation while diminishing hip flexor activation. Thus, the objective of the study was to investigate the effect of pelvic position and the Janda sit-up on trunk muscle activation. Sixteen male volunteers underwent electromyographic (EMG) testing of their abdominal and hip flexor muscles during a supine isometric double straight leg lift (DSLL) with the feet held approximately 5 cm above a board. The second exercise (Janda sit-up) was a sit-up action where participants simultaneously contracted the hamstrings and the abdominal musculature while holding an approximately 45 degrees angle at the knee. Root mean square surface electromyography was calculated for the Janda sit-up and DSLL under 3 pelvic positions: anterior, neutral, and posterior pelvic tilt. The selected muscles were the upper and lower rectus abdominis (URA, LRA), external obliques, lower abdominal stabilizers (LAS), rectus femoris, and biceps femoris. The Janda sit-up position demonstrated the highest URA and LRA activation and the lowest rectus femoris activation. The Janda sit-up and the posterior tilt were significantly greater (p < 0.01 and p < 0.05, respectively) than the anterior tilt for the URA and LRA muscles. Activation levels of the URA and LRA in neutral pelvis were significantly (p < 0.01 and p < 0.05, respectively) less than the Janda sit-up position, but not significantly different from the posterior tilt. No significant differences in EMG activity were found for the external obliques or LAS. No rectus femoris differences were found in the 3 pelvis positions. The results of this study indicate that pelvic position had a significant effect on the activation of selected trunk and hip muscles during isometric exercise, and the activation of the biceps femoris during the Janda sit-up reduced the activation of the rectus femoris while producing high levels of activation of the URA and LRA.

  5. BICEP's acceleration

    SciTech Connect

    Contaldi, Carlo R.

    2014-10-01

    The recent Bicep2 [1] detection of, what is claimed to be primordial B-modes, opens up the possibility of constraining not only the energy scale of inflation but also the detailed acceleration history that occurred during inflation. In turn this can be used to determine the shape of the inflaton potential V(φ) for the first time — if a single, scalar inflaton is assumed to be driving the acceleration. We carry out a Monte Carlo exploration of inflationary trajectories given the current data. Using this method we obtain a posterior distribution of possible acceleration profiles ε(N) as a function of e-fold N and derived posterior distributions of the primordial power spectrum P(k) and potential V(φ). We find that the Bicep2 result, in combination with Planck measurements of total intensity Cosmic Microwave Background (CMB) anisotropies, induces a significant feature in the scalar primordial spectrum at scales k∼ 10{sup -3} Mpc {sup -1}. This is in agreement with a previous detection of a suppression in the scalar power [2].

  6. COMPARATIVE ANALYSIS ON MUSCLE STRENGTH AMONG PATIENTS WHO UNDERWENT ARTHROSCOPIC TENOTOMY OF THE LONG HEAD OF THE BICEPS IN RELATION TO ESTHETIC DEFORMITY

    PubMed Central

    Almeida, Alexandre; Valin, Márcio Rangel; de Almeida, Nayvaldo Couto; Roveda, Gilberto; Agostini, Ana Paula

    2015-01-01

    Objective: To determine whether there was any discrepancy in elbow flexion strength among patients with and without evident clinical deformity resulting from arthroscopic tenotomy on the long head of the biceps. Method: A group of 120 patients who underwent this procedure were evaluated. After applying the exclusion criteria, 89 patients remained in the analysis. Eighteen months after the operation (median), the elbow flexion strength was measured in newtons using a digital dynamometer. Three consecutive measurements were made and the average was used. The dominant and non-dominant sides were compared. Sex, age and mean elbow flexion strength in the operated and contralateral arms of patients with and without apparent clinical deformity were evaluated. Results: The median elbow flexion strength among the patients with evident clinical deformity was 17.78 N for the dominant arm and 20.87 N for the non-dominant arm. The difference was 2.51 N. In the group without evident clinical deformity, the difference was 2.14 N. The median muscle strength in the operated arm was 17.26 N, while the median was 20.06 N in the non-operated arm, thus suggesting that there was a significant loss of muscle strength (p = 0.005). The difference in muscle strength loss between the patients with and without evident deformity was not considered statistically significant (p = 0.977). Conclusion: The patients who underwent arthroscopic tenotomy on the long head of the biceps with or without apparent clinical deformity from distal migration presented similar elbow flexion muscle strength. PMID:27047871

  7. ‘Serious thigh muscle strains’: beware the intramuscular tendon which plays an important role in difficult hamstring and quadriceps muscle strains

    PubMed Central

    Brukner, Peter; Connell, David

    2016-01-01

    Why do some hamstring and quadriceps strains take much longer to repair than others? Which injuries are more prone to recurrence? Intramuscular tendon injuries have received little attention as an element in ‘muscle strain’. In thigh muscles, such as rectus femoris and biceps femoris, the attached tendon extends for a significant distance within the muscle belly. While the pathology of most muscle injures occurs at a musculotendinous junction, at first glance the athlete appears to report pain within a muscle belly. In addition to the musculotendinous injury being a site of pathology, the intramuscular tendon itself is occasionally injured. These injuries have a variety of appearances on MRIs. There is some evidence that these injuries require a prolonged rehabilitation time and may have higher recurrence rates. Therefore, it is important to recognise the tendon component of a thigh ‘muscle strain’. PMID:26519522

  8. The influence of different jaw positions on the endurance and electromyographic pattern of the biceps brachii muscle in young adults with different occlusal characteristics.

    PubMed

    Ferrario, V F; Sforza, C; Serrao, G; Fragnito, N; Grassi, G

    2001-08-01

    To investigate the hypothesis of a functional coupling between the stomatognathic motor apparatus and the muscles of other body districts, as well as between occlusal conditions and neuromuscular performance, two groups of men (age range 20-26 years), with either normal occlusion (14 men) or malocclusion (15 men), sustained with their dominant arm a dumbbell weighing 80% of their maximum while maintaining different jaw positions: mouth open, without dental contact; mouth close, with light dental contact; maximum voluntary clench; maximum voluntary clench on two cotton rolls positioned on the posterior mandibular teeth; maximum voluntary clench on one cotton roll positioned on the right/left-side posterior mandibular teeth. Surface electromyography (EMG) of the biceps brachii muscle was performed, and the endurance time, mean root mean square (rms) potential, and mean median power frequency were computed. The mean potential and median power frequency were also computed for 2-s windows, and values as a function of time were interpolated by a linear regression analysis. Data were compared between groups and trials by using a factorial analysis of variance. The malocclusion group subjects could perform the exercise for a longer time span than the normal occlusion individuals (P < 0.005). During this endurance time their biceps brachii muscles contracted with different patterns: on average, in the malocclusion group they had a larger EMG amplitude (P < 0.005), and a shift of the power spectrum toward lower frequencies (P < 0.005). The factor 'jaw position' was significant only for the endurance time (P < 0.005). In both groups, the longest endurance time was found in the 'clench' trial, while the shortest in the 'right-side bite' trial. In conclusion, a morphologically altered occlusion does not always worsen the muscular performance of other body districts, and the use of occlusal supports (cotton rolls) is not always beneficial.

  9. Complications of Proximal Biceps Tenotomy and Tenodesis.

    PubMed

    Virk, Mandeep S; Nicholson, Gregory P

    2016-01-01

    The long head of biceps tendon (LHBT) is a well-recognized cause of anterior shoulder pain. Tenotomy or tenodesis of the LHBT is an effective surgical solution for relieving pain arising from the LHBT. Cosmetic deformity of the arm, cramping or soreness in the biceps muscle, and strength deficits in elbow flexion and supination are the three most common adverse events associated with tenotomy of the LHBT. Complications associated with tenodesis of the LHBT include loss of fixation resulting in cosmetic deformity, residual groove pain, pain or soreness in the biceps muscle, infection, stiffness, hematoma, neurologic injury, vascular injury, proximal humerus fracture, and reflex sympathetic dystrophy.

  10. Measurement of Intramuscular Fat by Muscle Echo Intensity

    PubMed Central

    Young, Hui-Ju; Jenkins, Nathan T.; Zhao, Qun; McCully, Kevin K.

    2015-01-01

    Purpose To compare ultrasound echo intensity (EI) to high-resolution T1-weighted MRI and to establish calibration equations to estimate percent intramuscular fat from EI. Methods Thirty-one participants underwent both ultrasound and MRI testing of 4 muscles: rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and medial gastrocnemius (MG). Results Strong correlations were found between MRI percent fat and muscle EI after correcting for subcutaneous fat thickness (r = 0.91 in RF, r = 0.80 in BF, r = 0.80 in TA, r = 0.76 in MG). Three types of calibration equations were established. Conclusion Muscle ultrasound is a practical and reproducible method that can be used as an imaging technique for examination of percent intramuscular fat. Future ultrasound studies are needed to establish equations for other muscle groups to enhance its use in both research and clinical settings. PMID:25787260

  11. Muscle Activation Differs Between Partial And Full Back Squat Exercise With External Load Equated.

    PubMed

    Jarbas da Silva, Josinaldo; Schoenfeld, Brad Jon; Marchetti, Priscyla Nardi; Pecoraro, Silvio Luis; D'Andréa Greve, Julia Maria; Marchetti, Paulo Henrique

    2017-02-13

    Changes in range of motion affect the magnitude of the load during the squat exercise and, consequently may influence muscle activation. The purpose of this study was to evaluate muscle activation between the partial and full back squat exercise with external load equated on a relative basis between conditions. Fifteen young, healthy, resistance trained men (age: 26±5 years, height: 173±6 cm) performed a back squat at their 10 repetition maximum using two different ranges of motion (partial and full) in a randomized, counterbalanced fashion. Surface electromyography was used to measure muscle activation of the vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), semitendinosus (ST), erector spinae (ES), soleus (SL), and gluteus maximus (GM). In general, muscle activity was highest during the partial back squat for GM (P=0.004), BF (P=0.009), and SL (P=0.031) when compared to full. There was no significant difference for RPE between partial and full back squat exercise at 10RM (8±1 and 9±1, respectively). In conclusion, the range of motion in the back squat alters muscle activation of the prime mover (gluteus maximus), and stabilizers (soleus and biceps femoris) when performed with the load equated on a relative basis. Thus, the partial back squat maximizes the level of muscle activation of the gluteus maximus and associated stabilizer muscles.

  12. Relative contributions of animal and muscle effects to variation in beef lean color stability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beef carcasses (n = 100) were selected from a commercial processing facility. Longissimus lumborum (LM), semimembranosus (SM), biceps femoris (BF), gluteus medius (GM), triceps brachii (TB), rectus femoris (RF), vastus lateralis (VL), adductor (AD), semitendinosus (ST), infraspinatus (IS), teres ma...

  13. Loop biceps tenotomy: an arthroscopic technique for long head of biceps tenotomy.

    PubMed

    Goubier, Jean-Noel; Bihel, Thomas; Dubois, Elodie; Teboul, Frédéric

    2014-08-01

    The long head of the biceps tendon is frequently involved in shoulder pathologies, often in relation to inflammatory or degenerative damage to the rotator cuff. Biceps tenodesis in the bicipital groove and tenotomy are the main treatment options. Tenotomy of the long head of the biceps tendon is a simpler and quicker procedure than tenodesis, and it does not require the use of implants. However, retraction of the biceps tendon, leading to Popeye deformity, and biceps muscle cramps are common complications after tenotomy. Therefore we propose an arthroscopic technique for tenotomy that limits the risk of Popeye deformity. This procedure consists of creating a loop at the severed end of the biceps tendon, which prevents the tendon from retracting into the bicipital groove.

  14. Diagnosis and treatment of biceps tendinitis and tendinosis.

    PubMed

    Churgay, Catherine A

    2009-09-01

    Biceps tendinitis is inflammation of the tendon around the long head of the biceps muscle. Biceps tendinosis is caused by degeneration of the tendon from athletics requiring overhead motion or from the normal aging process. Inflammation of the biceps tendon in the bicipital groove, which is known as primary biceps tendinitis, occurs in 5 percent of patients with biceps tendinitis. Biceps tendinitis and tendinosis are commonly accompanied by rotator cuff tears or SLAP (superior labrum anterior to posterior) lesions. Patients with biceps tendinitis or tendinosis usually complain of a deep, throbbing ache in the anterior shoulder. Repetitive overhead motion of the arm initiates or exacerbates the symptoms. The most common isolated clinical finding in biceps tendinitis is bicipital groove point tenderness with the arm in 10 degrees of internal rotation. Local anesthetic injections into the biceps tendon sheath may be therapeutic and diagnostic. Ultrasonography is preferred for visualizing the overall tendon, whereas magnetic resonance imaging or computed tomography arthrography is preferred for visualizing the intra-articular tendon and related pathology. Conservative management of biceps tendinitis consists of rest, ice, oral analgesics, physical therapy, or corticosteroid injections into the biceps tendon sheath. Surgery should be considered if conservative measures fail after three months, or if there is severe damage to the biceps tendon.

  15. Electromyographic analysis of lower limb muscles during the golf swing performed with three different clubs.

    PubMed

    Marta, Sérgio; Silva, Luís; Vaz, João Rocha; Castro, Maria António; Reinaldo, Gustavo; Pezarat-Correia, Pedro

    2016-01-01

    The aim of this study was to describe and compare the EMG patterns of select lower limb muscles throughout the golf swing, performed with three different clubs, in non-elite middle-aged players. Fourteen golfers performed eight swings each using, in random order, a pitching wedge, 7-iron and 4-iron. Surface electromyography (EMG) was recorded bilaterally from lower limb muscles: tibialis anterior, peroneus longus, gastrocnemius medialis, gastrocnemius lateralis, biceps femoris, semitendinosus, gluteus maximus, vastus medialis, rectus femoris and vastus lateralis. Three-dimensional high-speed video analysis was used to determine the golf swing phases. Results showed that, in average handicap golfers, the highest muscle activation levels occurred during the Forward Swing Phase, with the right semitendinosus and the right biceps femoris muscles producing the highest mean activation levels relative to maximal electromyography (70-76% and 68-73% EMG(MAX), respectively). Significant differences between the pitching wedge and the 4-iron club were found in the activation level of the left semitendinosus, right tibialis anterior, right peroneus longus, right vastus medialis, right rectus femuris and right gastrocnemius muscles. The lower limb muscles showed, in most cases and phases, higher mean values of activation on electromyography when golfers performed shots with a 4-iron club.

  16. Muscle activation and strength in squat and Bulgarian squat on stable and unstable surface.

    PubMed

    Andersen, V; Fimland, M S; Brennset, O; Haslestad, L R; Lundteigen, M S; Skalleberg, K; Saeterbakken, A H

    2014-12-01

    The aim of the study was to compare muscle activity using the same relative resistance in squats and Bulgarian squats on stable and unstable surface. Muscle strength and activity were assessed by 6-repetition maximum and concomitant surface electromyography. A cohort of 15 resistance-trained males performed the exercises on the floor or a foam cushion in randomized order. The muscle activity was greater in biceps femoris (63-77%, p<0.01) and core muscle external obliques (58-62%, p<0.05) for the Bulgarian squat compared to regular squats, but lower for rectus femoris (16-21%, p<0.05). Only Bulgarian squat showed differences concerning the surface, e. g. the unstable surface reduced the activation of erector spinae (10%, p<0.05) and biceps femoris (10%, p<0.05) compared to a stable surface. There were similar activations in the vasti muscles and rectus abdominis between the different exercises (p=0.313-0.995). Unstable surfaces resulted in a load decrement of 7% and 10% compared to stable surfaces (p<0.001). In conclusion, the squat was somewhat favorable for the activation of agonists, whereas Bulgarian squat was advantageous for the antagonist and somewhat for core muscles. Bulgarian- and regular squats complement each other, and it may be useful to include both in a periodized resistance training program.

  17. Muscle Activation Patterns in Infants with Myelomeningocele Stepping on a Treadmill

    PubMed Central

    Sansom, Jennifer K.; Teulier, Caroline; Smith, Beth A.; Moerchen, Victoria; Muraszko, Karin; Ulrich, Beverly D.

    2013-01-01

    Purpose To characterize how infants with myelomeningocele (MMC) activate lower limb muscles over the first year of life, without practice, while stepping on a motorized treadmill. Methods Twelve infants with MMC were tested longitudinally at 1, 6, 12 months. Electromyography (EMG) was used to collect data from the tibialis anterior (TA), lateral gastrocnemius (LG), rectus femoris (RF), biceps femoris (BF). Results Across the first year, infants showed no EMG activity for ~50% of the stride cycle w/poor rhythmicity and timing of muscles, when activated. Single muscle activation predominated; agonist-antagonist co-activation was low. Probability of individual muscle activity across the stride decreased w/age. Conclusions Infants with MMC show high variability in timing and duration of muscle activity, few complex combinations, and very little change over time. PMID:23685739

  18. Expression profiles of myostatin, myogenin, and Myosin heavy chain in skeletal muscles of two rabbit breeds differing in growth rate.

    PubMed

    Kuang, Liangde; Xie, Xiaohong; Zhang, Xiangyu; Lei, Min; Li, Congyan; Ren, Yongjun; Zheng, Jie; Guo, Zhiqiang; Zhang, Cuixia; Yang, Chao; Zheng, Yucai

    2014-01-01

    The purpose of the present study was to compare mRNA levels of myostatin (MSTN), myogenin (MyoG), and fiber type compositions in terms of myosin heavy chain (MyHC) in skeletal muscles of two rabbit breeds with different body sizes and growth rates. Longissimus dorsi and biceps femoris muscles of 16 Californian rabbits (CW) and 16 Germany great line of ZIKA rabbits (GZ) were collected at the ages of 35d and 84d (slaughter age). The results showed that the live weights of GZ rabbits of 35d and 84d old were approximately 36% and 26% greater than those of CW rabbits, respectively. Quantitative real-time PCR analysis revealed that at the age of 84d GZ rabbits contained significantly lower MSTN mRNA level and higher MyoG mRNA level in both longissimus dorsi and biceps femoris muscles than CW rabbits, and mRNA levels of MSTN and MyoG exhibited opposite changes from the age of 35d to 84d, suggesting that GZ rabbits were subjected to less growth inhibition from MSTN at slaughter age, which occurred most possibly in skeletal muscles. Four types of fiber were identified by real-time PCR in rabbit muscles, with MyHC-1 and MyHC-2D, MyHC-2B were the major types in biceps femoris and longissimus dorsi muscles, respectively. At the age of 84d, GZ rabbits contained greater proportion of MyHC-1 and decreased proportion of MyHC-2D and decreased lactate dehydrogenase activity in biceps femoris than CW rabbits, and the results were exactly opposite in longissimus dorsi, suggesting that GZ rabbits show higher oxidative capacity in biceps femoris muscle than CW rabbits. In conclusion, the trends of mRNA levels of MSTN and fiber types in GZ rabbits' skeletal muscles might be consistent with the putative fast growth characteristic of GZ rabbits compared to CW rabbits.

  19. The effect of squat depth on multiarticular muscle activation in collegiate cross-country runners.

    PubMed

    Gorsuch, Joshua; Long, Janey; Miller, Katie; Primeau, Kyle; Rutledge, Sarah; Sossong, Andrew; Durocher, John J

    2013-09-01

    The squat is a closed-chain lower body exercise commonly performed by many athletes. Muscle activity has been examined during partial and parallel squats in male weightlifters, but not in male and female runners. Therefore, this study measured muscle activity with surface electromyography (EMG) during partial and parallel squats in 20 Division I collegiate cross-country runners (10 males and 10 females) in a randomized crossover design. We hypothesized the parallel squat would increase extensor muscle activitation (i.e. hamstrings and erector spinae). Furthermore, we sought to determine if changes in muscle activity were different between males and females. Participants performed 6 repetitions using their 10 repetition maximum loads for each condition during EMG testing. EMG was performed on the right rectus femoris, biceps femoris, lumbar erector spinae, and lateral head of the gastrocnemius. Rectus femoris activity (0.18 ± 0.01 vs. 0.14 ± 0.01 mV) and erector spinae activity (0.16 ± 0.01 vs. 0.13 ± 0.01 mV) were significantly higher (p < 0.05) during the parallel squat than during the partial squat condition. This increase in muscle activity may be attributed to greater ranges of motion at the hip and knee joints. Biceps femoris and gastrocnemius activity were similar between conditions. No significant differences existed between males and females (squat condition × gender; p > 0.05). During preliminary isokinetic testing, both male and female runners demonstrated deficient hamstrings-to-quadriceps ratios, which would not likely improve by performing parallel squats based on our EMG findings. Despite the reduced load of the parallel squat, rectus femoris and erector spinae activity were elevated. Thus, parallel squats may help runners to train muscles vital for uphill running and correct posture, while preventing injury by using lighter weights through a larger range of motion.

  20. An analysis on muscle tone of lower limb muscles on flexible flat foot.

    PubMed

    Um, Gi-Mai; Wang, Joong-San; Park, Si-Eun

    2015-10-01

    [Purpose] The aim of this study was to examine differences in the muscle tone and stiffness of leg muscles according to types of flexible flat foot. [Subjects and Methods] For 30 subjects 10 in a normal foot group (NFG), 10 in group with both flexible flat feet (BFFG), and 10 in a group with flexible flat feet on one side (OFFG), myotonometry was used to measure the muscle tone and stiffness of the tibialis anterior muscle (TA), the rectus femoris muscle (RF), the medial gastrocnemius (MG), and the long head of the biceps femoris muscle (BF) of both lower extremities. [Results] In the measurement results, only the stiffness of TA and MG of the NFG and the BFFG showed significant differences. The muscle tone and stiffness were highest in the BFFG, followed by the OFFG and NFG, although the difference was insignificant. In the case of the OFFG, there was no significant difference in muscle tone and stiffness compared to that in the NGF and the BFFG. Furthermore, in the NFG, the non-dominant leg showed greater muscle tone and stiffness than the dominant leg, although the difference was insignificant. [Conclusion] During the relax condition, the flexible flat foot generally showed a greater muscle tone and stiffness of both lower extremities compared to the normal foot. The stiffness was particularly higher in the TA and MG muscles. Therefore, the muscle tone and stiffness of the lower extremity muscles must be considered in the treatment of flat foot.

  1. [Proximal and distal rupture of the m. biceps brachii].

    PubMed

    Lorbach, O; Kieb, M; Grim, C; Engelhardt, M

    2010-12-01

    Ruptures of the biceps tendon account for a high percentage of tendon ruptures. The aetiology of proximal ruptures of the long head of the biceps tendon is often degenerative and they are frequently associated with lesions of the rotator cuff. The clinical findings are often not specific and long lasting. Distal ruptures of the biceps tendon mostly occur during eccentric contraction of the biceps muscle.Clinical tests, the associated haematoma and a distalisation or proximalisation of the muscle belly in combination with ultrasound or MRI to rule out combined diseases lead to the diagnosis. The possible options include conservative and operative treatment. Tenotomy and tenodesis lead to comparable results in the literature. Therefore, conservative treatment is mostly recommended in proximal ruptures. Operative treatment is preferred in distal ruptures of the biceps tendon in order to achieve an anatomical reconstruction of the muscle function. Chronic ruptures of the distal biceps tendon can be successfully treated with free autografts or allografts.

  2. Effects of combined exercise on changes of lower extremity muscle activation during walking in older women

    PubMed Central

    Park, Jaehyun; Lee, Joongsook; Yang, Jeongok; Lee, Bomjin; Han, Dongwook

    2015-01-01

    [Purpose] The purpose of this study was to demonstrate the effects of combined exercise for a period of 12 weeks on the changes in lower extremity muscle activation during walking in older women. [Subjects] The subjects of this study were 22 elderly women who were 65 years of age or older and living in B-City. The subjects had no nervous system or muscular system diseases that might affect walking in the previous two years. [Methods] Muscle activation was measured by using surface EMG (QEMG-8, Laxtha, Daejeon, Republic of Korea). The subjects were asked to walk on an 8 m of footpath at a natural speed. In order to minimize the noise from the cable connecting the EMG measuring instrument to the electrodes, tape was used to affix the electrodes so that they would not fall off the subjects. The EMG data were analyzed by using the RMS. [Results] Muscle activation of the rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius was increased significantly after combined exercise for 12 weeks. However, no increase was observed in the left biceps femoris. [Conclusion] It was demonstrated that our exercise program, which includes aerobic walking exercises, senior-robics, and muscle strengthening exercises using elastic bands, is very effective for reorganizing the normal gait pattern in the cerebral cortex and improving muscle strength. PMID:26157253

  3. Muscle force estimation with surface EMG during dynamic muscle contractions: a wavelet and ANN based approach.

    PubMed

    Bai, Fengjun; Chew, Chee-Meng

    2013-01-01

    Human muscle force estimation is important in biomechanics studies, sports and assistive devices fields. Therefore, it is essential to develop an efficient algorithm to estimate force exerted by muscles. The purpose of this study is to predict force/torque exerted by muscles under dynamic muscle contractions based on continuous wavelet transform (CWT) and artificial neural networks (ANN) approaches. Mean frequency (MF) of the surface electromyography (EMG) signals power spectrum was calculated from CWT. ANN models were trained to derive the MF-force relationships from the subset of EMG signals and the measured forces. Then we use the networks to predict the individual muscle forces for different muscle groups. Fourteen healthy subjects (10 males and 4 females) were voluntarily recruited in this study. EMG signals were collected from the biceps brachii, triceps, hamstring and quadriceps femoris muscles to evaluate the proposed method. Root mean square errors (RMSE) and correlation coefficients between the predicted forces and measured actual forces were calculated.

  4. Rectus Femoris Tendon Calcification

    PubMed Central

    Zini, Raul; Panascì, Manlio; Papalia, Rocco; Franceschi, Francesco; Vasta, Sebastiano; Denaro, Vincenzo

    2014-01-01

    Background: Since it was developed, hip arthroscopy has become the favored treatment for femoroacetabular impingement. Due to recent considerable improvements, the indications for this technique have been widely extended. Injuries of the rectus femoris tendon origin, after an acute phase, could result in a chronic tendinopathy with calcium hydroxyapatite crystal deposition, leading to pain and loss of function. Traditionally, this condition is addressed by local injection of anesthetic and corticosteroids or, when conservative measures fail, by open excision of the calcific lesion by an anterior approach. Purpose: To assess whether arthroscopic excision of calcification of the proximal rectus is a safe and effective treatment. Study Design: Case series; Level of evidence, 4. Methods: Outcomes were studied from 6 top amateur athletes (age range, 30-43 years; mean, 32.6 years) affected by calcification of the proximal rectus who underwent arthroscopic excision of the calcification. Patients were preoperatively assessed radiographically, and diagnosis was confirmed by a 3-dimensional computed tomography scan. To evaluate the outcome, standardized hip rating scores were used pre- and postoperatively (at 6 and 12 months): the Hip disability and Osteoarthritis Outcome Score, Oxford Hip Score, and Modified Harris Hip Score. Moreover, visual analog scales (VAS) for pain, sport activity level (SAL), and activities of daily living (ADL) were also used. Results: One year after surgery, all patients reported satisfactory outcomes, with 3 of 6 rating their return-to-sport level as high as preinjury level, and the remaining 3 with a percentage higher than 80%. Five patients ranked their ability to carry on daily activities at 100%. Statistical analysis showed significant improvement of the Oxford Hip Score, the Modified Harris Hip Score, and all 3 VAS subscales (pain, SAL, and ADL) from pre- to latest postoperative assessment (P < .05). Conclusion: Arthroscopic excision of

  5. Biceps tendinitis as a cause of acute painful knee after total knee arthroplasty.

    PubMed

    Pandher, Dilbans Singh; Boparai, Randhir Singh; Kapila, Rajesh

    2009-12-01

    The case report highlights an unusual case of posterolateral knee pain after total knee arthroplasty. Tendinitis of the patellar tendon or pes anserinus is a common complication after total knee arthroplasty; however, there is no report in the literature regarding the biceps femoris tendinitis causing acute pain in the early postoperative period. In this case, the biceps tendinitis was diagnosed and treated by ultrasound-guided injection into the tendon sheath.

  6. The Effects of Positive and Negative Feedback on Maximal Voluntary Contraction Level of the Biceps Brachii Muscle: Moderating Roles of Gender and Conscientiousness.

    PubMed

    Sarıkabak, Murat; Yaman, Çetin; Tok, Serdar; Binboga, Erdal

    2016-11-02

    We investigated the effect of positive and negative feedback on maximal voluntary contraction (MVC) of the biceps brachii muscle and explored the mediating effects of gender and conscientiousness. During elbow flexion, MVCs were measured in positive, negative, and no-feedback conditions. Participants were divided into high- and low-conscientiousness groups based on the median split of their scores on Tatar's five-factor personality inventory. Considering all participants 46 college student athletes (21 female, 28 male), positive feedback led to a greater MVC percentage change (-5.76%) than did negative feedback (2.2%). MVC percentage change in the positive feedback condition differed significantly by gender, but the negative feedback condition did not. Thus, positive feedback increased female athletes' MVC level by 3.49%, but decreased male athletes' MVC level by 15.6%. For conscientiousness, MVC percentage change in the positive feedback condition did not differ according to high and low conscientiousness. However, conscientiousness interacted with gender in the positive feedback condition, increasing MVC in high-conscientiousness female athletes and decreasing MVC in low-conscientiousness female athletes. Positive feedback decreased MVC in both high- and low-conscientiousness male athletes.

  7. Subpectoral Biceps Tenodesis.

    PubMed

    Levy, David M; Meyer, Zachery I; Campbell, Kirk A; Bach, Bernard R

    2016-02-01

    Biceps tenodesis is a common procedure performed for tendinopathy of the long head of the biceps brachii (LHB). Indications include partial-thickness LHB tear, tendon subluxation with or without subscapularis tear, and failed conservative management of bicipital tenosynovitis. Biceps tenodesis may also be performed for superior labrum anterior to posterior tears. Evaluation of biceps stability is important in the treatment of LHB pathology. We advocate a technique of subpectoral biceps tenodesis. Interference screw fixation has demonstrated biomechanical superiority in laboratory models. If there are any concomitant operations, such as rotator cuff repair, the postoperative rehabilitation protocol may need to be adjusted. Overall, subpectoral biceps tenodesis with interference screw fixation has had excellent clinical outcomes and low complication rates.

  8. Strength and muscle activities during the toe-gripping action: comparison of ankle angle in the horizontal plane between the sitting upright and standing positions

    PubMed Central

    Soma, Masayuki; Murata, Shin; Kai, Yoshihiro; Nakae, Hideyuki; Satou, Yousuke

    2016-01-01

    [Purpose] The aim of this study was to investigate whether toe grip strength and muscle activities are affected by the ankle angle in the horizontal plane in the sitting upright and standing positions. [Subjects] The subjects were 16 healthy young women. [Methods] We measured toe grip strength and the maximum voluntary contraction activities of the rectus femoris, biceps femoris, anterior tibialis, and medial head of the gastrocnemius. In addition, we calculated the percent integrated electromyography during foot gripping in 3 different ankle joint positions between the long axis of the foot and the line of progression on the horizontal plane, namely 10° of internal rotation, 0°, and 10° of external rotation. [Results] Two-way analysis of variance revealed significant differences. A significant main effect was observed in the measurement conditions for the percent integrated electromyography of the rectus femoris muscle and long head of the biceps femoris. However, two-way analysis of variance did not reveal any significant difference, and a significant main effect was not observed in toe grip strength. [Conclusion] These findings suggest that exerted toe grip strength is only slightly affected by the ankle angle in the horizontal plane in the sitting upright and standing positions. Therefore, the current measurement positions were shown to be optimal for measurement. PMID:27134399

  9. Muscle and intensity based hamstring exercise classification in elite female track and field athletes: implications for exercise selection during rehabilitation

    PubMed Central

    Tsaklis, Panagiotis; Malliaropoulos, Nikos; Mendiguchia, Jurdan; Korakakis, Vasileios; Tsapralis, Kyriakos; Pyne, Debasish; Malliaras, Peter

    2015-01-01

    Background Hamstring injuries are common in many sports, including track and field. Strains occur in different parts of the hamstring muscle but very little is known about whether common hamstring loading exercises specifically load different hamstring components. The purpose of this study was to investigate muscle activation of different components of the hamstring muscle during common hamstring loading exercises. Methods Twenty elite female track and field athletes were recruited into this study, which had a single-sample, repeated-measures design. Each athlete performed ten hamstring loading exercises, and an electromyogram (EMG) was recorded from the biceps femoris and semitendinosus components of the hamstring. Hamstring EMG during maximal voluntary isometric contraction (MVIC) was used to normalize the mean data across ten repetitions of each exercise. An electrogoniometer synchronized to the EMG was used to determine whether peak EMG activity occurred during muscle-tendon unit lengthening, shortening, or no change in length. Mean EMG values were compared between the two recording sites for each exercise using the Student’s t-test. Results The lunge, dead lift, and kettle swings were low intensity (<50% MVIC) and all showed higher EMG activity for semitendinosus than for biceps femoris. Bridge was low but approaching medium intensity, and the TRX, hamstring bridge, and hamstring curl were all medium intensity exercises (≥50% or <80% MVIC). The Nordic, fitball, and slide leg exercises were all high intensity exercises. Only the fitball exercise showed higher EMG activity in the biceps femoris compared with the semitendinosus. Only lunge and kettle swings showed peak EMG in the muscle-tendon unit lengthening phase and both these exercises involved faster speed. Conclusion Some exercises selectively activated the lateral and medial distal hamstrings. Low, medium, and high intensity exercises were demonstrated. This information enables the clinician, strength

  10. The effects of horseback riding simulator exercises on the muscle activity of the lower extremities according to changes in arm posture

    PubMed Central

    Park, Jungseo; Lee, Sangyong; Lee, Daehee

    2015-01-01

    [Purpose] This study aimed to determine the effects of horseback riding simulator exercise on the muscle activities of the lower extremities according to changes in arm posture. [Subjects] The subjects of this study were 30 normal adult males and females. [Methods] The horseback riding simulator exercise used a horseback riding simulator device; two arm postures were used, posture 1 (holding the handle of the device) and posture 2 (crossing both arms, with both hands on the shoulders). Electromyography was used to compare the muscle activities of the rectus femoris, biceps femoris, and hip adductors in the lower extremities. [Results] Posture 2 had significantly higher muscle activity than posture 1. [Conclusion] Posture 2, which entailed crossing both arms with both hands on the shoulders, was an effective intervention for improved muscle activity in the hip adductors. PMID:26504280

  11. The effect of temperature on apoptosis and adipogenesis on skeletal muscle satellite cells derived from different muscle types

    PubMed Central

    Harding, Rachel L; Clark, Daniel L; Halevy, Orna; Coy, Cynthia S; Yahav, Shlomo; Velleman, Sandra G

    2015-01-01

    Satellite cells are multipotential stem cells that mediate postnatal muscle growth and respond differently to temperature based upon aerobic versus anaerobic fiber-type origin. The objective of this study was to determine how temperatures below and above the control, 38°C, affect the fate of satellite cells isolated from the anaerobic pectoralis major (p. major) or mixed fiber biceps femoris (b. femoris). At all sampling times, p. major and b. femoris cells accumulated less lipid when incubated at low temperatures and more lipid at elevated temperatures compared to the control. Satellite cells isolated from the p. major were more sensitive to temperature as they accumulated more lipid at elevated temperatures compared to b. femoris cells. Expression of adipogenic genes, CCAAT/enhancer-binding protein β (C/EBPβ) and proliferator-activated receptor gamma (PPARγ) were different within satellite cells isolated from the p. major or b. femoris. At 72 h of proliferation, C/EBPβ expression increased with increasing temperature in both cell types, while PPARγ expression decreased with increasing temperature in p. major satellite cells. At 48 h of differentiation, both C/EBPβ and PPARγ expression increased in the p. major and decreased in the b. femoris, with increasing temperature. Flow cytometry measured apoptotic markers for early apoptosis (Annexin-V-PE) or late apoptosis (7-AAD), showing less than 1% of apoptotic satellite cells throughout all experimental conditions, therefore, apoptosis was considered biologically not significant. The results support that anaerobic p. major satellite cells are more predisposed to adipogenic conversion than aerobic b. femoris cells when thermally challenged. PMID:26341996

  12. The effect of temperature on apoptosis and adipogenesis on skeletal muscle satellite cells derived from different muscle types.

    PubMed

    Harding, Rachel L; Clark, Daniel L; Halevy, Orna; Coy, Cynthia S; Yahav, Shlomo; Velleman, Sandra G

    2015-09-01

    Satellite cells are multipotential stem cells that mediate postnatal muscle growth and respond differently to temperature based upon aerobic versus anaerobic fiber-type origin. The objective of this study was to determine how temperatures below and above the control, 38°C, affect the fate of satellite cells isolated from the anaerobic pectoralis major (p. major) or mixed fiber biceps femoris (b. femoris). At all sampling times, p. major and b. femoris cells accumulated less lipid when incubated at low temperatures and more lipid at elevated temperatures compared to the control. Satellite cells isolated from the p. major were more sensitive to temperature as they accumulated more lipid at elevated temperatures compared to b. femoris cells. Expression of adipogenic genes, CCAAT/enhancer-binding protein β (C/EBPβ) and proliferator-activated receptor gamma (PPARγ) were different within satellite cells isolated from the p. major or b. femoris. At 72 h of proliferation, C/EBPβ expression increased with increasing temperature in both cell types, while PPARγ expression decreased with increasing temperature in p. major satellite cells. At 48 h of differentiation, both C/EBPβ and PPARγ expression increased in the p. major and decreased in the b. femoris, with increasing temperature. Flow cytometry measured apoptotic markers for early apoptosis (Annexin-V-PE) or late apoptosis (7-AAD), showing less than 1% of apoptotic satellite cells throughout all experimental conditions, therefore, apoptosis was considered biologically not significant. The results support that anaerobic p. major satellite cells are more predisposed to adipogenic conversion than aerobic b. femoris cells when thermally challenged.

  13. Biceps Tenotomy Versus Tenodesis.

    PubMed

    Patel, Kushal V; Bravman, Jonathan; Vidal, Armando; Chrisman, Ashley; McCarty, Eric

    2016-01-01

    Long head biceps tendon is a common cause of anterior shoulder pain. Failure of conservative treatment may warrant surgical intervention. Surgical treatment involves long head biceps tenotomy or tenodesis. Several different techniques have been described for biceps tenodesis, including arthroscopic versus open and suprapectoral versus subpectoral. Most studies comparing tenodesis to tenotomy are limited by the level of evidence and confounding factors, such as concomitant rotator cuff tear. Many studies demonstrate similar outcomes for both procedures. Surgeon preference is likely more influential in choosing between tenotomy and tenodesis. Higher-powered studies are necessary to elucidate any differences in outcomes if present.

  14. Proximal Biceps Tendonitis

    MedlinePlus

    ... teens, biceps tendonitis is usually an overuse injury. Baseball pitchers, swimmers, tennis players, and people who have ... But if you swim or play tennis or baseball, that might not be an option! If your ...

  15. Characteristics of lower limb muscle activity during upper limb elevation in badminton players

    PubMed Central

    Masu, Yujiro; Nagai, Masanori

    2016-01-01

    [Purpose] To clarify the characteristics of postural control in badminton players by examining their lower-limb muscle activity during upper-limb elevation. [Subjects and Methods] Fourteen badminton players and 14 non-players were studied. The subjects were instructed to perform an upper-limb elevation task in order to measure the activities of the biceps femoris and biceps brachii. [Results] When elevating the dominant hand, the mean biceps femoris integrated electromyogram showed markedly higher values in the player group, for the contralateral compared with the ipsilateral leg. Similarly, when elevating the dominant hand, the difference in the maximum integrated electromyogram response time between the ipsilateral and contralateral legs was significantly smaller in the players compared with non-players. [Conclusion] It may be possible to reduce the time needed to elevate the dominant hand by shifting lower-limb activity from the ipsilateral to the contralateral leg more quickly, while increasing the rate of rise in contralateral leg muscle activity. PMID:27799681

  16. Biceps tendinitis and subluxation.

    PubMed

    Patton, W C; McCluskey, G M

    2001-07-01

    Since the 17th century, the long head of the biceps tendon as a source of shoulder pain and its functional significance has been a source of debate. Although the term tendinitis is commonly used, overuse tendon injuries infrequently demonstrate inflammatory cells; instead, degenerative changes resulting from the failure of self-repair usually are found. Bicipital tendinitis or bicipital tenosynovitis is most often secondary to impingement beneath the coracoacromical arch. Primary bicipital tendinitis and tendinitis secondary to instability are possible, however. Through a careful history, physical examination, and appropriate imaging studies, the clinician can establish the diagnosis of disorders of the biceps tendon Arthroscopic evaluation greatly improves the diagnosis and treatment of biceps tendon and related shoulder pathology. Although the exact functional role of the biceps tendon remains incompletely defined, a growing body of evidence supports its role as a stabilizer of the glenohumeral joint. This stabilizing function should be incorporated into the treatment of biceps tendon disorders. Routine tenodesis has been replaced by a more individualized approach, taking into consideration physiologic age, activity level, expectations, and exact shoulder pathology present. New repair techniques are under development, and preservation of the biceps-labral complex is now preferred when possible.

  17. Effects of postmortem aging and USDA quality grade on Warner-Bratzler shear force values of seventeen individual beef muscles.

    PubMed

    Gruber, S L; Tatum, J D; Scanga, J A; Chapman, P L; Smith, G C; Belk, K E

    2006-12-01

    Forty USDA Select and 40 upper two-thirds USDA Choice beef carcasses were used to determine the effects of postmortem aging on tenderness of 17 individual beef muscles. Biceps femoris-long head, complexus, gluteus medius, infraspinatus, longissimus dorsi, psoas major, rectus femoris, semimembranosus, semitendinosus, serratus ventralis, spinalis dorsi, supraspinatus, tensor fasciae latae, teres major, triceps brachii-long head, vastus lateralis, and vastus medialis muscles were removed from each carcass. Seven steaks (2.54-cm thick) were cut from every muscle, and each steak was assigned to one of the following postmortem aging periods: 2, 4, 6, 10, 14, 21, or 28 d postmortem. After completion of the designated aging period, steaks were removed from storage (2 degrees C, never frozen), cooked to a peak internal temperature of 71 degrees C, and evaluated using Warner-Bratzler shear force (WBSF). Analysis of WBSF revealed a 3-way interaction (P = 0.004) among individual muscle, USDA quality grade, and postmortem aging period. With the exception of the Select teres major, WBSF of all muscles (both quality grades) decreased with increasing time of postmortem storage. Nonlinear regression was used to characterize the extent (aging response) and rate of decrease in WBSF from 2 through 28 d postmortem for each muscle within each quality grade. In general, WBSF of upper two-thirds Choice muscles decreased more rapidly from 2 to 10 d postmortem than did corresponding Select muscles. Muscles that had greater aging responses generally had greater 2-d WBSF values. The upper two-thirds Choice psoas major, serratus ventralis, and vastus lateralis muscles required similar aging times to complete a majority of the aging response (< or =0.1 kg of aging response remaining) compared with analogous Select muscles. The upper two-thirds Choice complexus, gluteus medius, semitendinosus, triceps brachii-long head, and vastus medialis muscles required 4 to 6 d less time to complete a

  18. [Morphohistochemical study of skeletal muscles in rats after experimental flight on "Kosmos-1887"].

    PubMed

    Il'ina-Kakueva, E I

    1990-01-01

    Morphometric and histochemical methods were used to examine the soleus, gastrocnemius (medial portion), quadriceps femoris (central portion) and biceps brachii muscles of Wistar SPF rats two days after the 13-day flight on Cosmos-1887. It was found that significant atrophy developed only in the soleus muscle. The space flight did not change the percentage content of slow (type I) and fast (type II) fibers in fast twitch muscles. During two days at 1 g the slow soleus muscle developed substantial circulation disorders, which led to interstitial edema and necrotic changes. The gastrocnemius muscle showed small foci containing necrotic myofibers. Two days after recovery no glycogen aggregates were seen in myofibers, which were previously observed in other rats examined 4--8 hours after flight. An initial stage of muscle readaptation to 1 g occurred, when NAD.H2-dehydrogenase activity was decreased.

  19. Lower muscle co-contraction in flutter kicking for competitive swimmers.

    PubMed

    Matsuda, Yuji; Hirano, Masami; Yamada, Yosuke; Ikuta, Yasushi; Nomura, Teruo; Tanaka, Hiroaki; Oda, Shingo

    2016-02-01

    The purpose of this study was to examine the difference in muscle activation pattern and co-contraction of the rectus and biceps femoris in flutter-kick swimming between competitive and recreational swimmers, to better understand the mechanism of repetitive kicking movements during swimming. Ten competitive and 10 recreational swimmers swam using flutter kicks at three different velocities (100%, 90%, and 80% of their maximal velocity) in a swimming flume. Surface electromyographic signals (EMG) were obtained from the rectus (RF) and biceps femoris (BF), and lower limb kinematic data were obtained at the same time. The beginning and ending of one kick cycle was defined as when the right lateral malleolus reached its highest position in the vertical axis. The offset timing of muscle activation of RF in the recreational swimmers was significantly later at all velocities than in the competitive swimmers (47-48% and 26-33% of kick time of one cycle for recreational and competitive swimmers, respectively), although the kinematic data and other activation timing of RF and BF did not differ between groups. A higher integrated EMG of RF during hip extension and knee extension induced a higher level of muscle co-contraction between RF and BF in the recreational swimmers. These results suggest that long-term competitive swimming training can induce an effective muscle activation pattern in the upper legs.

  20. Muscle Activation Differs between Three Different Knee Joint-Angle Positions during a Maximal Isometric Back Squat Exercise

    PubMed Central

    Jarbas da Silva, Josinaldo; Jon Schoenfeld, Brad; Nardi, Priscyla Silva Monteiro; Pecoraro, Silvio Luis; D'Andréa Greve, Julia Maria; Hartigan, Erin

    2016-01-01

    The purpose of this study was to compare muscle activation of the lower limb muscles when performing a maximal isometric back squat exercise over three different positions. Fifteen young, healthy, resistance-trained men performed an isometric back squat at three knee joint angles (20°, 90°, and 140°) in a randomized, counterbalanced fashion. Surface electromyography was used to measure muscle activation of the vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), semitendinosus (ST), and gluteus maximus (GM). In general, muscle activity was the highest at 90° for the three quadriceps muscles, yet differences in muscle activation between knee angles were muscle specific. Activity of the GM was significantly greater at 20° and 90° compared to 140°. The BF and ST displayed similar activation at all joint angles. In conclusion, knee position alters muscles activation of the quadriceps and gluteus maximus muscles. An isometric back squat at 90° generates the highest overall muscle activation, yet an isometric back squat at 140° generates the lowest overall muscle activation of the VL and GM only. PMID:27504484

  1. Skeletal muscle adaptations to prolonged exposure to extreme altitude: a role of physical activity?

    PubMed

    Mizuno, Masao; Savard, Gabrielle K; Areskog, Nils-Holger; Lundby, Carsten; Saltin, Bengt

    2008-01-01

    This study investigated skeletal muscle adaptations to high altitude and a possible role of physical activity levels. Biopsies were obtained from the m. quadriceps femoris (vastus) and m. biceps brachii (biceps) in 15 male subjects, 7 active and 8 less active. Samples were obtained at sea level and after 75 days altitude exposure at 5250 m or higher. The muscle fiber size decreased at an average of 15% in the vastus and biceps, respectively, and to the same extent in both groups. In both muscles, the mean number of capillaries was 2.1-2.2 cap.fiber(-1) before and after the exposure. As mean fiber area was reduced, the mean number of capillaries per unit area increased in all subjects (from 320 to 405 cap/mm2) with no difference between the active and less active groups. The two enzymes selected to reflect mitochondrial capacity, citrate synthase (CS) and 3-hydroxyl-CoA-dehydrogenase (HAD), did not change in the leg muscles with altitude exposure, CS: 28.7 (20.7-37.8) vs. 27.8 (23.8-29.4); HAD: 35.2 (20.3-43.1) vs. 30.6 (20.7-39.7) micromol.min(-1).g(-1) d.w, pre- and post-altitude, respectively. The muscle buffer capacity was elevated in both the vastus; 220 (194-240) vs. 232 (200-277) and the biceps muscles; 233 (190-301) vs. 253 (193-320) after the acclimatization period. In conclusion, mean fiber area was reduced in response to altitude exposure regardless of physical activity which in turn meant that with an unaltered capillary to fiber ratio there was an elevation in capillaries per unit of muscle area. Muscle enzyme activity was unaffected with altitude exposure in both groups, whereas muscle buffer capacity was increased.

  2. Distal biceps tendon injuries: diagnosis and management.

    PubMed

    Ramsey, M L

    1999-01-01

    Rupture of the distal biceps tendon occurs most commonly in the dominant extremity of men between 40 and 60 years of age when an unexpected extension force is applied to the flexed arm. Although previously thought to be an uncommon injury, distal biceps tendon ruptures are being reported with increasing frequency. The rupture typically occurs at the tendon insertion into the radial tuberosity in an area of preexisting tendon degeneration. The diagnosis is made on the basis of a history of a painful, tearing sensation in the antecubital region. Physical examination demonstrates a palpable and visible deformity of the distal biceps muscle belly with weakness in flexion and supination. The ability to palpate the tendon in the antecubital fossa may indicate partial tearing of the biceps tendon. Plain radiographs may show hypertrophic bone formation at the radial tuberosity. Magnetic resonance imaging is generally not required to diagnose a complete rupture but may be useful in the case of a partial rupture. Early surgical reattachment to the radial tuberosity is recommended for optimal results. A modified two-incision technique is the most widely used method of repair, but anterior single-incision techniques may be equally effective provided the radial nerve is protected. The patient with a chronic rupture may benefit from surgical reattachment, but proximal retraction and scarring of the muscle belly can make tendon mobilization difficult, and inadequate length of the distal biceps tendon may necessitate tendon augmentation. Postoperative rehabilitation must emphasize protected return of motion for the first 8 weeks after repair. Formal strengthening may begin as early as 8 weeks, with a return to unrestricted activities, including lifting, by 5 months.

  3. A comparison of the moment arms of pelvic limb muscles in horses bred for acceleration (Quarter Horse) and endurance (Arab).

    PubMed

    Crook, T C; Cruickshank, S E; McGowan, C M; Stubbs, N; Wilson, A M; Hodson-Tole, E; Payne, R C

    2010-07-01

    Selective breeding for performance has resulted in distinct breeds of horse, such as the Quarter Horse (bred for acceleration) and the Arab (bred for endurance). Rapid acceleration, seen during Quarter Horse racing, requires fast powerful muscular contraction and the generation of large joint torques, particularly by the hind limb muscles. This study compared hind limb moment arm lengths in the Quarter Horse and Arab. We hypothesized that Quarter Horse hind limb extensor muscles would have longer moment arms when compared to the Arab, conferring a greater potential for torque generation at the hip, stifle and tarsus during limb extension. Six Quarter Horse and six Arab hind limbs were dissected to determine muscle moment arm lengths for the following muscles: gluteus medius, biceps femoris, semitendinosus, vastus lateralis, gastrocnemius (medialis and lateralis) and tibialis cranialis. The moment arms of biceps femoris (acting at the hip) and gastrocnemius lateralis (acting at the stifle) were significantly longer in the Quarter Horse, although the length of the remaining muscle moment arms were similar in both breeds of horse. All the Quarter Horse muscles were capable of generating greater muscle moments owing to their greater physiological cross-sectional area (PCSA) and therefore greater isometric force potential, which suggests that PCSA is a better determinant of muscle torque than moment arm length in these two breeds of horse. With the exception of gastrocnemius and tibialis cranialis, the observed muscle fascicle length to moment arm ratio (MFL : MA ratio) was greater for the Arab horse muscles. It appears that the Arab muscles have the potential to operate at slower velocities of contraction and hence generate greater force outputs when compared to the Quarter Horse muscles working over a similar range of joint motion; this would indicate that Arab hind limb muscles are optimized to function at maximum economy rather than maximum power output.

  4. Three-layered architecture of the popliteal fascia that acts as a kinetic retinaculum for the hamstring muscles.

    PubMed

    Satoh, Masahiro; Yoshino, Hiroyuki; Fujimura, Akira; Hitomi, Jiro; Isogai, Sumio

    2016-09-01

    When patients report pain in the popliteal fossa upon knee extension, the pain is usually localized in the lower region of the popliteal fossa. However, some patients complain of pain in the upper region of the popliteal fossa as the knee is flexed, which motivated us to examine the role of the popliteal fascia as the retinaculum of the hamstring muscles. Thirty-four thighs from 19 Japanese cadavers were dissected. The popliteal fascia was defined as the single aponeurotic sheet covering the popliteal fossa. We found that the fascia acted as a three-layered retinaculum for the flexor muscles of the thigh and provided a secure route for neurovascular structures to the lower leg in any kinetic position of the knee joint. The superficial layer of the popliteal fascia covering the thigh was strongly interwoven with the epimysium of biceps femoris along its lateral aspect and with that of the semimembranosus along its medial aspect, ensuring that the flexor muscles remained in their correct positions. The intermediate layer arose from the medial side of biceps femoris and merged medially with the superficial layer. The profound layer stretched transversely between the biceps femoris and the semimembranosus. Moreover, we investigated the nerve distribution in the popliteal fascia using Sihler's staining and whole-mount immunostaining for neurofilaments. The three-layered fascia was constantly innervated by branches from the posterior femoral cutaneous or saphenous nerve. The nerves were closely related and distributed to densely packed collagen fibers in the superficial layer as free or encapsulated nerve endings, suggesting that the fascia is involved in pain in the upper region of the popliteal fossa.

  5. Distal Biceps Tendon Rupture

    DTIC Science & Technology

    2010-06-01

    distal tendon. Although these findings overlap with those seen in tendinopathy , the presence of bone marrow edema at the radial tuberosity and fluid in...the bicipitoradial bursa suggests a partial tear rather than tendinopathy .3 When the distal biceps tendon tear is complete, MR imaging shows

  6. Lower extremity muscle activation during baseball pitching.

    PubMed

    Campbell, Brian M; Stodden, David F; Nixon, Megan K

    2010-04-01

    The purpose of this study was to investigate muscle activation levels of select lower extremity muscles during the pitching motion. Bilateral surface electromyography data on 5 lower extremity muscles (biceps femoris, rectus femoris, gluteus maximus, vastus medialis, and gastrocnemius) were collected on 11 highly skilled baseball pitchers and compared with individual maximal voluntary isometric contraction (MVIC) data. The pitching motion was divided into 4 distinct phases: phase 1, initiation of pitching motion to maximum stride leg knee height; phase 2, maximum stride leg knee height to stride foot contact (SFC); phase 3, SFC to ball release; and phase 4, ball release to 0.5 seconds after ball release (follow-through). Results indicated that trail leg musculature elicited moderate to high activity levels during phases 2 and 3 (38-172% of MVIC). Muscle activity levels of the stride leg were moderate to high during phases 2-4 (23-170% of MVIC). These data indicate a high demand for lower extremity strength and endurance. Specifically, coaches should incorporate unilateral and bilateral lower extremity exercises for strength improvement or maintenance and to facilitate dynamic stabilization of the lower extremities during the pitching motion.

  7. The effects of bicycle frame geometry on muscle activation and power during a wingate anaerobic test.

    PubMed

    Ricard, Mark D; Hills-Meyer, Patrick; Miller, Michael G; Michael, Timothy J

    2006-01-01

    The purpose of this study was to compare the effects of bicycle seat tube angles (STA) of (72° and 82°) on power production and EMG of the vastus laeralis (VL), vastus medialis (VM), semimembranous (SM), biceps femoris (BF) during a Wingate test (WAT). Twelve experienced cyclists performed a WAT at each STA. Repeated measures ANOVA was used to identify differences in muscular activation by STA. EMG variables were normalized to isometric maximum voluntary contraction (MVC). Paired t-tests were used to test the effects of STA on: peak power, average power, minimum power and percent power drop. Results indicated BF activation was significantly lower at STA 82° (482.9 ± 166.6 %MVC·s) compared to STA 72° (712.6 ± 265.6 %MVC·s). There were no differences in the power variables between STAs. The primary finding was that increasing the STA from 72° to 82° enabled triathletes' to maintain power production, while significantly reducing the muscular activation of the biceps femoris muscle. Key PointsRoad cyclists claim that bicycle seat tube angles between 72° and 76° are most effective for optimal performance in racing.Triathletes typically use seat tube angles greater than 76°. It is thought that a seat tube angle greater than 76° facilitates a smoother bike to run transition in the triathlon.Increasing the seat tube angle from 72 to 82 enabled triathletes' to maintain power production, while significantly reducing the muscular activation of the biceps femoris muscle.Reduced hamstring muscular activation in the triathlon frame (82 seat tube angle) may serve to reduce hamstring tightness following the bike phase of the triathlon, allowing the runner to use a longer stride length.

  8. Chemical composition, quality and histochemical characteristics of individual dromedary camel (Camelus dromedarius) muscles.

    PubMed

    Kadim, I T; Al-Karousi, A; Mahgoub, O; Al-Marzooqi, W; Khalaf, S K; Al-Maqbali, R S; Al-Sinani, S S H; Raiymbek, G

    2013-03-01

    This study characterized the chemical composition, quality and histological traits of six muscles from 10 dromedary carcasses. There were significant differences in moisture, fat, protein, mineral, saturated and unsaturated fatty acid contents between muscles. The longissimus thoracis (LT) had the highest cooking loss (33.5%) and triceps brachii (TB) the lowest (29.2%). The shear force value of semitendinosus (ST), semimembranosus (SM) and biceps femoris (BF) were significantly higher than infraspinatus (IS), TB and LT. The LT had significantly higher values for L*, a*, b* than ST. The SM had the lowest MFI (65.3), while IS had the highest value (75.8). The ST significantly had the highest and lowest proportions of Type I and Type IIA muscle fibers, respectively than other muscles. This study indicated that composition, quality, and histochemical parameters varied among camel muscles and the knowledge of this variation allows for better marketing and processing of camel meat.

  9. Changes in muscle coordination and power output during sprint cycling.

    PubMed

    O'Bryan, Steven J; Brown, Nicholas A T; Billaut, François; Rouffet, David M

    2014-07-25

    This study investigated the changes in muscle coordination associated to power output decrease during a 30-s isokinetic (120rpm) cycling sprint. Modifications in EMG amplitude and onset/offset were investigated from eight muscles [gluteus maximus (EMGGMAX), vastus lateralis and medialis obliquus (EMGVAS), medial and lateral gastrocnemius (EMGGAS), rectus femoris (EMGRF), biceps femoris and semitendinosus (EMGHAM)]. Changes in co-activation of four muscle pairs (CAIGMAX/GAS, CAIVAS/GAS, CAIVAS/HAM and CAIGMAX/RF) were also calculated. Substantial power reduction (60±6%) was accompanied by a decrease in EMG amplitude for all muscles other than HAM, with the greatest deficit identified for EMGRF (31±16%) and EMGGAS (20±14%). GASonset, HAMonset and GMAXonset shifted later in the pedalling cycle and the EMG offsets of all muscles (except GASoffset) shifted earlier as the sprint progressed (P<0.05). At the end of the sprint, CAIVAS/GAS and CAIGMAX/GAS were reduced by 48±10% and 43±12%, respectively. Our results show that substantial power reduction during fatiguing sprint cycling is accompanied by marked reductions in the EMG activity of bi-articular GAS and RF and co-activation level between GAS and main power producer muscles (GMAX and VAS). The observed changes in RF and GAS EMG activity are likely to result in a redistribution of the joint powers and alterations in the orientation of the pedal forces.

  10. Acute Effects of Different Methods of Stretching and Specific Warm-ups on Muscle Architecture and Strength Performance.

    PubMed

    Sá, Marcos A; Matta, Thiago T; Carneiro, Simone P; Araujo, Carolina O; Novaes, Jefferson S; Oliveira, Liliam F

    2016-08-01

    Sá, MA, Matta, TT, Carneiro, SP, Araujo, CO, Novaes, JS, and Oliveira, LF. Acute effects of different methods of stretching and specific warm-ups on muscle architecture and strength performance. J Strength Cond Res 30(8): 2324-2329, 2016-The purpose of the study was to investigate the acute effects of 2 stretching interventions, proprioceptive neuromuscular facilitation (PNF) and passive static stretching (PSS), and a specific warm-up (SW) on the strength and architecture of the vastus laterallis and biceps femoris muscles in a subsequent performance on a strength training session (STS). Musculoskeletal ultrasound images were acquired from 9 men before and immediately after stretchings or a SW, and 10 minutes after a STS. The STS consisted of the following exercises: leg extension, leg curl, leg press, and hack machine squat. The PNF resulted in lower performance for all situations. The PSS and SW improved performance for the leg press compared with the PNF and controls (CSs). For the hack machine squat, SWs resulted in higher performance than stretching conditions. The vastus lateralis muscle fascicle length (FL) increases after a STS for PNF. The biceps femoris muscle showed a higher pennation angle 10 minutes after the STS for PSS; the FL increases immediately after PSS and then decreases 10 minutes after the STS for PSS. As per our results, the SWs should be performed before STSs, whereas PNF stretching should not be prescribed because this condition impairs subsequent performance. These results may assist health professionals in prescribing resistance training.

  11. Muscle force output and electromyographic activity in squats with various unstable surfaces.

    PubMed

    Saeterbakken, Atle H; Fimland, Marius S

    2013-01-01

    The purpose of the study was to compare force output and muscle activity of leg and trunk muscles in isometric squats executed on stable surface (i.e., floor), power board, BOSU ball, and balance cone. Fifteen healthy men (23.3 ± 2.7 years, mass: 80.5 ± 8.5 kg, height: 1.81 ± 0.09 m) volunteered. The force output and electromyographic (EMG) activities of the rectus femoris, vastus medialis, vastus lateralis, biceps femoris, soleus, rectus abdominis, oblique external, and erector spinae were assessed. The order of the surfaces was randomized. One familiarization session was executed before the experimental test. Compared with stable surface (749 ± 222 N), the force output using power board was similar (-7%, p = 0.320) but lower for BOSU ball (-19%, p = 0.003) and balance cone (-24%, p ≤ 0.001). The force output using BOSU ball and balance cone was approximately 13% (p = 0.037) and approximately 18% (p = 0.001) less than the power board. There were similar EMG activities between the surfaces in all muscles except for rectus femoris, in which stable squat provided greater EMG activity than did the other exercises (p = 0.004-0.030). Lower EMG activity was observed in the rectus femoris using balance cone compared with the BOSU ball (p = 0.030). In conclusion, increasing the instability of the surface during maximum effort isometric squats usually maintains the muscle activity of lower-limb and superficial trunk muscles although the force output is reduced. This suggests that unstable surfaces in the squat may be beneficial in rehabilitation and as a part of periodized training programs, because similar muscle activity can be achieved with reduced loads.

  12. Biceps tendinitis caused by an osteochondroma in the bicipital groove: a rare cause of shoulder pain in a baseball player.

    PubMed

    Onga, Takafumi; Yamamoto, Tetsuji; Akisue, Toshihiro; Marui, Takashi; Kurosaka, Masahiro

    2005-02-01

    Tendinitis of the long head of the biceps brachii muscle is commonly seen in athletes who do repetitive overhead motions. Common causes of biceps tendinitis include impingement syndrome, subluxation of the biceps tendon, and attrition tendinitis, whereas biceps tendinitis secondary to a bone neoplasm is rare. A case of biceps tendinitis caused by an osteochondroma arising in the left humeral bicipital groove in a 25-year-old male baseball player is reported. The tumor was hook-shaped, originated from the inferomedial portion of the humeral lesser tubercle, and surrounded the biceps tendon. Symptoms of increasing pain and inability to throw resulted from direct irritation of the biceps tendon by the tumor. Total excision of the tumor relieved the symptoms within 3 weeks. To our knowledge, there have been no reported cases in the English-language literature of biceps tendinitis caused by an osteochondroma.

  13. Electromyographic responses of erector spinae and lower limb's muscles to dynamic postural perturbations in patients with adolescent idiopathic scoliosis.

    PubMed

    Farahpour, Nader; Ghasemi, Safoura; Allard, Paul; Saba, Mohammad Sadegh

    2014-10-01

    The aim of this study was to evaluate electromyographic (EMG) responses of erector spinae (ES) and lower limbs' muscles to dynamic forward postural perturbation (FPP) and backward postural perturbation (BPP) in patients with adolescent idiopathic scoliosis (AIS) and in a healthy control group. Ten right thoracic AIS patients (Cobb=21.6±4.4°) and 10 control adolescents were studied. Using bipolar surface electrodes, EMG activities of ES muscle at T10 (EST10) and L3 (ESL3) levels, biceps femoris (BF), gastrocnemius lateralis (G) and rectus femoris (RF) muscles in the right and the left sides during FPP and BPP were evaluated. Muscle responses were measured over a 1s time window after the onset of perturbation. In FPP test, the EMG responses of right EST10, ESL3 and BF muscles in the scoliosis group were respectively about 1.40 (p=0.035), 1.43 (p=0.07) and 1.45 (p=0.01) times greater than those in control group. Also, in BPP test, at right ESL3 muscle of the scoliosis group the EMG activity was 1.64 times higher than that in the control group (p=0.01). The scoliosis group during FPP displayed asymmetrical muscle responses in EST10 and BF muscles. This asymmetrical muscle activity in response to FPP is hypothesized to be a possible compensatory strategy rather than an inherent characteristic of scoliosis.

  14. Assessment of muscle fatigue after an ultra-endurance triathlon using tensiomyography (TMG).

    PubMed

    García-Manso, Juan Manuel; Rodríguez-Ruiz, David; Rodríguez-Matoso, Dario; de Saa, Yves; Sarmiento, Samuel; Quiroga, Miriam

    2011-03-01

    In this study, we used tensiomyography (TMG) to assess muscle status immediately after an ultra-endurance triathlon. Maximal radial displacement or deformation of the muscle belly, contraction time, delay time, sustain time, and relaxation time were measured for both legs, and dependent t-tests were used to compare means between the beginning and end of the race. The 19 men assessed (age 37.9 ± 7.1 years; height 177.5 ± 4.6 cm; weight: 73.6 ± 6.5 kg) participated in the 2009 edition of the Lanzarote Ironman. Deterioration in the neural response was observed for contraction time (P = 0.008) and relaxation time (P = 0.011), with a moderate decrease in the response time (sustain time) and a loss in muscle stiffness (deformation of the muscle belly). The effect of muscle fatigue on the rectus femoris and biceps femoris was different. Barely any changes in contraction time, relaxation time, sustain time, and deformation of the muscle belly were observed, while only the contraction response time decreased to a significant extent (reduction in delay time; P = 0.003). The considerable loss in contractile capacity induced by a long-distance race was reflected in changes in the neuromuscular response and fluctuations in the contractile capacity of the muscle. These modifications, derived from a prolonged, exhausting effort, can be assessed in a simple, non-aggressive, non-invasive way using tensiomyography.

  15. Musculo-tendon length and lengthening velocity of rectus femoris in stiff knee gait.

    PubMed

    Jonkers, Ilse; Stewart, Caroline; Desloovere, Kaat; Molenaers, Guy; Spaepen, Arthur

    2006-02-01

    Inappropriate activity of M. rectus femoris (RF) during swing is believed to contribute to stiff knee gait in cerebral palsy. This study used musculoskeletal modeling techniques to analyze rectus femoris musculo-tendon (MT) length and lengthening velocity during stiff knee gait in 35 children with diplegic cerebral palsy (CP). Duncan Ely test scores were used to categorize the patients into four groups with increasing levels of rectus femoris spasticity. Knee kinematics confirmed a significant reduction and delay of maximal peak knee flexion during swing in the patient groups compared to reference values. Maximal musculo-tendon length of M. rectus femoris was reduced and occurred prematurely in swing. Musculo-tendon lengthening velocity was significantly reduced and the timing of the maximal lengthening velocity was shifted into stance phase. The present study demonstrates altered dynamic behavior of the M. rectus femoris in stiff knee gait and the results indicate that maximal knee flexion in swing was not a valid reference for the MT length of the M. rectus femoris. Furthermore, in the patient group maximal musculo-tendon lengthening velocity of the muscle related to the stance phase rather than the stance-swing transition.

  16. Muscular Activity and Fatigue in Lower-Limb and Trunk Muscles during Different Sit-To-Stand Tests

    PubMed Central

    Roldán-Jiménez, Cristina; Bennett, Paul; Cuesta-Vargas, Antonio I.

    2015-01-01

    Sit-to-stand (STS) tests measure the ability to get up from a chair, reproducing an important component of daily living activity. As this functional task is essential for human independence, STS performance has been studied in the past decades using several methods, including electromyography. The aim of this study was to measure muscular activity and fatigue during different repetitions and speeds of STS tasks using surface electromyography in lower-limb and trunk muscles. This cross-sectional study recruited 30 healthy young adults. Average muscle activation, percentage of maximum voluntary contraction, muscle involvement in motion and fatigue were measured using surface electrodes placed on the medial gastrocnemius (MG), biceps femoris (BF), vastus medialis of the quadriceps (QM), the abdominal rectus (AR), erector spinae (ES), rectus femoris (RF), soleus (SO) and the tibialis anterior (TA). Five-repetition STS, 10-repetition STS and 30-second STS variants were performed. MG, BF, QM, ES and RF muscles showed differences in muscle activation, while QM, AR and ES muscles showed significant differences in MVC percentage. Also, significant differences in fatigue were found in QM muscle between different STS tests. There was no statistically significant fatigue in the BF, MG and SO muscles of the leg although there appeared to be a trend of increasing fatigue. These results could be useful in describing the functional movements of the STS test used in rehabilitation programs, notwithstanding that they were measured in healthy young subjects. PMID:26506612

  17. Effects of ACL reconstruction surgery on muscle activity of the lower limb during a jump-cut maneuver in males and females

    PubMed Central

    Coats-Thomas, Margaret S.; Miranda, Daniel L.; Badger, Gary J.; Fleming, Braden C.

    2013-01-01

    We compared muscle activity of the quadriceps, hamstring, and gastrocnemius muscles when ACL-intact (ACLINT) and ACL-reconstructed (ACLREC) male and female subjects performed a jump-cut task. Surface electromyography sensors were used to evaluate time to peak muscle activity and muscle activity ratios. Rectus femoris (RF) and vastus medialis (VM) peak timing was 71 ms and 78 ms earlier in ACLINT than in ACLREC subjects, respectively. Biceps femoris (BF) peak timing was 90 ms earlier in ACLINT than in ACLREC subjects and 75 ms earlier in females than in males. Medial gastrocnemius (MG) muscle peak timing was 77 ms earlier in ACLINT than in ACLREC subjects. Lateral gastrocnemius (LG) and MG muscle peak times were 106 ms and 87 ms earlier in females than in males, respectively. The RF, VM, BF and MG peaked later in ACLREC than in ACLINT subjects. There was evidence suggesting that the loading phase quadriceps:hamstring (quad:ham) muscle activity ratio was greater in ACLREC than in ACLINT subjects. Finally, the injury risk phase quad:ham muscle activity ratio was found to be 4.8 times greater in females than in males. In conclusion, there are differences in muscle activity related to ACL status and sex that could potentially help explain graft failure risk and the sex bias. PMID:23966333

  18. Effect of the shoulder position on the biceps brachii emg in different dumbbell curls.

    PubMed

    Oliveira, Liliam F; Matta, Thiago T; Alves, Daniel S; Garcia, Marco A C; Vieira, Taian M M

    2009-01-01

    Incline Dumbbell Curl (IDC) and Dumbbell Preacher Curl (DPC) are two variations of the standard Dumbbell Biceps Curl (DBC), generally applied to optimize biceps brachii contribution for elbow flexion by fixing shoulder at a specific angle. The aim of this study is to identify changes in the neuromuscular activity of biceps brachii long head for IDC, DPC and DBC exercises, by taking into account the changes in load moment arm and muscle length elicited by each dumbbell curl protocol. A single cycle (concentric-eccentric) of DBC, IDC and DPC, was applied to 22 subjects using a submaximal load of 40% estimated from an isometric MVC test. The neuromuscular activity of biceps brachii long head was compared by further partitioning each contraction into three phases, according to individual elbow joint range of motion. Although all protocols elicited a considerable level of activation of the biceps brachii muscle (at least 50% of maximum RMS), the contribution of this muscle for elbow flexion/extension varied among exercises. The submaximal elbow flexion (concentric) elicited neuro muscular activity up to 95% of the maximum RMS value during the final phase of IDC and DBC and 80% for DPC at the beginning of the movement. All exercises showed significant less muscle activity for the elbow extension (eccentric). The Incline Dumbbell Curl and the classical Dumbbell Biceps Curl resulted in similar patterns of biceps brachii activation for the whole range of motion, whereas Dumbbell Preacher Curl elicited high muscle activation only for a short range of elbow joint angle. Key pointsThe Incline Dumbbell Curl and the Dumbbell Biceps Curl resulted in a considerable neuromuscular effort throughout the whole elbow range of motion.The Incline Dumbbell Curl and the Dumbbell Biceps Curl may be preferable for the improvement of biceps brachii force in training programs.

  19. Effect of the shoulder position on the biceps brachii emg in different dumbbell curls

    PubMed Central

    Oliveira, Liliam F.; Matta, Thiago T.; Alves, Daniel S.; Garcia, Marco A.C.; Vieira, Taian M.M.

    2009-01-01

    Incline Dumbbell Curl (IDC) and Dumbbell Preacher Curl (DPC) are two variations of the standard Dumbbell Biceps Curl (DBC), generally applied to optimize biceps brachii contribution for elbow flexion by fixing shoulder at a specific angle. The aim of this study is to identify changes in the neuromuscular activity of biceps brachii long head for IDC, DPC and DBC exercises, by taking into account the changes in load moment arm and muscle length elicited by each dumbbell curl protocol. A single cycle (concentric-eccentric) of DBC, IDC and DPC, was applied to 22 subjects using a submaximal load of 40% estimated from an isometric MVC test. The neuromuscular activity of biceps brachii long head was compared by further partitioning each contraction into three phases, according to individual elbow joint range of motion. Although all protocols elicited a considerable level of activation of the biceps brachii muscle (at least 50% of maximum RMS), the contribution of this muscle for elbow flexion/extension varied among exercises. The submaximal elbow flexion (concentric) elicited neuro muscular activity up to 95% of the maximum RMS value during the final phase of IDC and DBC and 80% for DPC at the beginning of the movement. All exercises showed significant less muscle activity for the elbow extension (eccentric). The Incline Dumbbell Curl and the classical Dumbbell Biceps Curl resulted in similar patterns of biceps brachii activation for the whole range of motion, whereas Dumbbell Preacher Curl elicited high muscle activation only for a short range of elbow joint angle. Key pointsThe Incline Dumbbell Curl and the Dumbbell Biceps Curl resulted in a considerable neuromuscular effort throughout the whole elbow range of motion.The Incline Dumbbell Curl and the Dumbbell Biceps Curl may be preferable for the improvement of biceps brachii force in training programs. PMID:24150552

  20. Aging affects spatial distribution of leg muscle oxygen saturation during ramp cycling exercise.

    PubMed

    Takagi, Shun; Kime, Ryotaro; Murase, Norio; Watanabe, Tsubasa; Osada, Takuya; Niwayama, Masatsugu; Katsumura, Toshihito

    2013-01-01

    We compared muscle oxygen saturation (SmO2) responses in several leg muscles and within a single muscle during ramp cycling exercise between elderly men (n = 8; age, 65 ± 3 years; ELD) and young men (n = 10; age, 23 ± 3 years; YNG). SmO2 was monitored at the distal site of the vastus lateralis (VLd), proximal site of the vastus lateralis (VLp), rectus femoris (RF), vastus medialis (VM), biceps femoris (BF), gastrocnemius lateralis (GL), gastrocnemius medialis (GM), and tibialis anterior (TA) by near-infrared spatial resolved spectroscopy. During submaximal exercise, significantly lower SmO2 at a given absolute work rate was observed in VLd, RF, BF, GL, and TA but not in VLp, VM, and GM in ELD than in YNG. In contrast, at all measurement sites, SmO2 at peak exercise was not significantly different between groups. These results indicate that the effects of aging on SmO2 responses are heterogeneous between leg muscles and also within a single muscle. The lower SmO2 in older men may have been caused by reduced muscle blood flow or altered blood flow distribution.

  1. Approach run increases preactivation and eccentric phases muscle activity during drop jumps from different drop heights.

    PubMed

    Ruan, Mianfang; Li, Li

    2010-10-01

    The purpose of this study was to investigate the effects of a horizontal approach run and drop height on the activation of lower extremity muscles during drop jumps. Ten participants performed drop jumps from drop heights of 15, 30, 45 and 60cm with zero (standing), one, two, and three approach run steps. The EMG activities of the Gluteus Maximus (GM), Rectus Femoris (RF), Biceps Femoris (BF), Vastus Lateralis (VL), Tibialis Anterior (TA), Gastrocnemius (GA) and Soleus (SO) were recorded, full-wave rectified, and averaged (aEMG) during the preactivation (50ms before touchdown), downward, and push-off phases. Increasing drop height did not enhance the muscle activation level of any examined muscles except GA. During the preactivation phase, the aEMG of all muscles except TA increased with the number of approach run steps. The aEMG of RF, BF, VL, and SO also increased with the number of approach run steps during the downward phase, while no aEMG changes were observed during the push-off phase. These results suggest that a horizontal approach run preceding the drop jump is an effective strategy for increasing the muscle preactivation level, which contributes to a higher level of muscle activity during the eccentric contraction phase and could potentially contribute to the reported higher power output during the concentric contraction phase.

  2. Breakpoints in ventilation, cerebral and muscle oxygenation, and muscle activity during an incremental cycling exercise

    PubMed Central

    Racinais, Sebastien; Buchheit, Martin; Girard, Olivier

    2014-01-01

    The aim of this study was to locate the breakpoints of cerebral and muscle oxygenation and muscle electrical activity during a ramp exercise in reference to the first and second ventilatory thresholds. Twenty-five cyclists completed a maximal ramp test on an electromagnetically braked cycle-ergometer with a rate of increment of 25 W/min. Expired gazes (breath-by-breath), prefrontal cortex and vastus lateralis (VL) oxygenation [Near-infrared spectroscopy (NIRS)] together with electromyographic (EMG) Root Mean Square (RMS) activity for the VL, rectus femoris (RF), and biceps femoris (BF) muscles were continuously assessed. There was a non-linear increase in both cerebral deoxyhemoglobin (at 56 ± 13% of the exercise) and oxyhemoglobin (56 ± 8% of exercise) concomitantly to the first ventilatory threshold (57 ± 6% of exercise, p > 0.86, Cohen's d < 0.1). Cerebral deoxyhemoglobin further increased (87 ± 10% of exercise) while oxyhemoglobin reached a plateau/decreased (86 ± 8% of exercise) after the second ventilatory threshold (81 ± 6% of exercise, p < 0.05, d > 0.8). We identified one threshold only for muscle parameters with a non-linear decrease in muscle oxyhemoglobin (78 ± 9% of exercise), attenuation in muscle deoxyhemoglobin (80 ± 8% of exercise), and increase in EMG activity of VL (89 ± 5% of exercise), RF (82 ± 14% of exercise), and BF (85 ± 9% of exercise). The thresholds in BF and VL EMG activity occurred after the second ventilatory threshold (p < 0.05, d > 0.6). Our results suggest that the metabolic and ventilatory events characterizing this latter cardiopulmonary threshold may affect both cerebral and muscle oxygenation levels, and in turn, muscle recruitment responses. PMID:24782786

  3. The biceps tendons: From the top and from the bottom

    PubMed Central

    Brasseur, J.L.

    2011-01-01

    The biceps brachii muscle, which inserts proximally onto the scapula and distally onto the forearm, has several tendons with numerous anatomic peculiarities, which render their sonographic examination highly variable. Proximally, the tendon of the short head of the biceps inserts onto the coracoid process and that of the long head on the superior aspect of the glenoid. The distal biceps tendon is bifurcated, and it generally inserts on the radial tuberosity, around which it rolls during pronation/supination. There is a third distal structure, the Lacertus fibrosus, an aponeurosis that branches off from the medial aspect of the tendon, crossing the median artery and median nerve, and inserting on the superficial aponeurosis of the flexor muscles. The sonographic examination of these tendons focuses on nine separate zones of interest: the glenoid insertion of the long head, its extension to the upper pole of the humeral head, the rotator interval, the reflection to the upper bicipital groove, the bicipital groove, the upper myotendinous junction, the lower myotendinous junction, the distal tendon(s), and the inferior enthesis. Because of their morphological and topographical characteristics, the biceps tendons are subject to a variety of lesions, some of which are frequently misdiagnosed on the basis of clinical findings. Ultrasound plays an important role in detecting and characterizing these lesions. Proper examination of the biceps (the distal portion in particular) is a difficult task that cannot be improvised. PMID:23397031

  4. Comparative anatomy and muscle architecture of selected hind limb muscles in the Quarter Horse and Arab.

    PubMed

    Crook, T C; Cruickshank, S E; McGowan, C M; Stubbs, N; Wakeling, J M; Wilson, A M; Payne, R C

    2008-02-01

    The Quarter Horse (bred for acceleration) and the Arab (bred for endurance) are situated at either end of the equine athletic spectrum. Studies into the form and function of the leg muscles in human sprint and endurance runners have demonstrated that differences exist in their muscle architecture. It is not known whether similar differences exist in the horse. Six Quarter Horse and six Arab fresh hind limb cadavers were dissected to gain information on the muscle mass and architecture of the following muscles: gluteus medius; biceps femoris; semitendinosus; vastus lateralis; gastrocnemius; tibialis cranialis and extensor digitorum longus. Specifically, muscle mass, fascicle length and pennation angle were quantified and physiological cross-sectional area (PCSA) and maximum isometric force were estimated. The hind limb muscles of the Quarter Horse were of a significantly greater mass, but had similar fascicle lengths and pennation angles when compared with those of the Arab; this resulted in the Quarter Horse hind limb muscles having greater PCSAs and hence greater isometric force potential. This study suggests that Quarter Horses as a breed inherently possess large strong hind limb muscles, with the potential to accelerate their body mass more rapidly than those of the Arab.

  5. Muscle contributions to propulsion and braking during walking and running: insight from external force perturbations.

    PubMed

    Ellis, Richard G; Sumner, Bonnie J; Kram, Rodger

    2014-09-01

    There remains substantial debate as to the specific contributions of individual muscles to center of mass accelerations during walking and running. To gain insight, we altered the demand for muscular propulsion and braking by applying external horizontal impeding and aiding forces near the center of mass as subjects walked and ran on a treadmill. We recorded electromyographic activity of the gluteus maximus (superior and inferior portions), the gluteus medius, biceps femoris, semitendinosus/membrinosus, vastus medialis, lateral and medial gastrocnemius and soleus. We reasoned that activity in a propulsive muscle would increase with external impeding force and decrease with external aiding force whereas activity in a braking muscle would show the opposite. We found that during walking the gastrocnemius and gluteus maximus provide propulsion while the vasti are central in providing braking. During running, we found that the gluteus maximus, vastus medialis, gastrocnemius and soleus all contribute to propulsion.

  6. Surgical Management of Rectus Femoris Avulsion Among Professional Soccer Players

    PubMed Central

    Sonnery-Cottet, Bertrand; Barbosa, Nuno Camelo; Tuteja, Sanesh; Gardon, Roland; Daggett, Matt; Monnot, Damien; Kajetanek, Charles; Thaunat, Mathieu

    2017-01-01

    Background: Rectus femoris injuries are common among athletes, especially in kicking sports such as soccer; however, proximal rectus femoris avulsions in athletes are a relatively rare entity. Purpose/Hypothesis: The purpose of this study was to describe and report the results of an original technique of surgical excision of the proximal tendon remnant followed by a muscular suture repair. Our hypothesis was that this technique limits the risk of recurrence in high-level athletes and allows for rapid recovery without loss of quadriceps strength. Study Design: Case series; Level of evidence, 4. Methods: Our retrospective series included 5 players aged 31.8 ± 3.9 years with acute proximal rectus femoris avulsion injuries who underwent a surgical resection of the proximal tendon between March 2012 and June 2014. Four of these players had recurrent rectus femoris injuries in the 9 months before surgery, while 1 player had surgery after a first injury. Mean follow-up was 18.2 ± 12.6 months, and minimum follow-up was 9 months. We analyzed the age, sex distribution, physical examination outcomes, type and mechanism of injury, diagnosis, treatment and complications during surgery, postoperative follow-up, and time to return to play. The Lower Extremity Functional Scale (LEFS) and Marx scores were obtained at 3-month follow-up, and isokinetic tests were performed before return to sports. A telephone interview was completed to determine the presence of recurrence at an average follow-up of 18.2 months. Results: At 3-month follow-up, all patients had Marx activity scores of 16 and LEFS scores of 80. Return to the previous level of play occurred at a mean of 15.8 ± 2.6 weeks after surgery, and none of the athletes suffered a recurrence. Isokinetic test results were comparable between both sides. Conclusion: The surgical treatment of proximal rectus femoris avulsions, consisting of resection of the tendinous part of the muscle, is a reliable and safe technique allowing a

  7. Effects of whole-body vibration applied to lower extremity muscles during decline bench press exercise

    PubMed Central

    García-Gutiérrez, M.T.; Hazell, T.J.; Marín, P.J.

    2016-01-01

    Objectives: To evaluate the effects of whole-body vibration (WBV) on skeletal muscle activity and power performance of the upper body during decline bench press exercise at different loads. Methods: Forty-seven healthy young and active male students volunteered. Each performed dynamic decline bench press repetitions with and without WBV (50 Hz, 2.2 mm) applied through a hamstring bridge exercise at three different loads of their 1-repetition maximum (1RM): 30%, 50%, and 70% 1RM. Muscle activity of the triceps brachii (TB), biceps brachii (BB), pectoralis major (PM), and biceps femoris (BF) was measured with surface electromyography electrodes and kinetic parameters of the repetitions were measured with a rotary encoder. Results: WBV increased peak power (PP) output during the 70% 1RM condition (p<0.01). Muscle activity was increased with WBV in the TB and BF muscles at all loads (p<0.05). There were no effects of WBV on BB or PM muscles. Conclusion: WBV applied through a hamstring bridge exercise increases TB muscle activity during a decline bench press and this augmentation contributes to an increased peak power at higher loads and increased peak acceleration at lower loads. PMID:27609035

  8. Effect of instability training equipment on lower limb kinematics and muscle activity.

    PubMed

    Pfusterschmied, J; Lindinger, S; Buchecker, M; Stöggl, T; Wagner, H; Müller, E

    2013-03-01

    To improve the effectiveness of training or therapy, it is important to know the benefits for each type of instability training equipment. The aim of this study was to show differences in lower limb kinematics and muscle activation during single leg standing on a slackline (SL) compared to a multi-functional rocker board (MD) and an air cushion (AC). In 14 subjects, mean angular velocity of the hip, knee and ankle, as well as the muscle activity (iEMG) from six lower limb muscles were recorded during 12 s of single leg standing task. Ankle in-/eversion and knee ab-/adduction angular velocity were highest for SL followed by MD and AC (all p < 0.05), as well as in the hip flex-/extension angular velocity with higher values for SL compared with AC (p < 0.01). Regarding iEMG, the rectus femoris muscle showed higher values for SL compared with MD (p < 0.05) and AC (p < 0.01). iEMG of biceps femoris muscle demonstrated higher values for MD compared to AC (p < 0.05), but with no difference to SL. Balancing on a SL is a more challenging exercise for the postural control system compared to MD and AC, and affects the knee and hip joint motion in particular.

  9. Do sarcomere length, collagen content, pH, intramuscular fat and desmin degradation explain variation in the tenderness of three ovine muscles?

    PubMed

    Starkey, Colin P; Geesink, Geert H; Collins, Damian; Hutton Oddy, V; Hopkins, David L

    2016-03-01

    The longissimus (n=118) (LL), semimembranosus (n=104) (SM) and biceps femoris (n=134) (BF) muscles were collected from lamb and sheep carcases and aged for 5days (LL and SM) and 14days (BF) to study the impact of muscle characteristics on tenderness as assessed by shear force (SF) and sensory evaluation. The impact of gender, animal age, collagen content, sarcomere length (SL), desmin degradation, ultimate pH and intramuscular fat (IMF) on tenderness was examined. The main factors which influenced SF of the LL were IMF, SL and desmin degradation, but for sensory tenderness, IMF, ultimate pH and gender were the main factors. The SF and sensory tenderness of the SM was best predicted by the degree of desmin degradation. For the BF soluble collagen and animal age both influenced SF. Different factors affect tenderness across muscles and not one prediction model applied across all muscles equally well.

  10. Effects of individual strengthening exercises for the stabilization muscles on the nutation torque of the sacroiliac joint in a sedentary worker with nonspecific sacroiliac joint pain.

    PubMed

    Yoo, Won-Gyu

    2015-01-01

    [Purpose] We investigated the effects of individual strengthening exercises for the stabilization muscles on the nutation torque of the sacroiliac joint in a sedentary worker with nonspecific sacroiliac joint pain. [Subject] A 36-year-old female complained of pain in the sacroiliac joints. [Methods] The subject performed individual strengthening exercises for the stabilization muscles for nutation torque of the sacroiliac joint for 3 weeks. Pain-provocation tests and visual analog scale (VAS) scores were evaluated before and after the exercises. [Results] After performing the individual strengthening exercises for the erector spinae, rectus abdominis, and biceps femoris muscles for 3 weeks, the subject displayed no pain in the pain provocation tests, and the VAS score was 2/10. [Conclusion] The individual strengthening exercises for the stabilization muscles of the sacroiliac joint performed in the present study appear to be effective for sedentary workers with sacroiliac joint pain.

  11. The relationship between RMS electromyography and thickness change in the skeletal muscles.

    PubMed

    Kian-Bostanabad, Sharareh; Azghani, Mahmood-Reza

    2017-02-27

    The knowledge of muscle function may affect prescribing medications and physical treatments. Recently, ultrasound and electromyography (EMG) have been used to assess the skeletal muscles activity. The relationship between these methods has been reported in numerous articles qualitatively. In this paper, the relationship between EMG root-mean-square (RMS) and ultrasound data of muscle thickness has been investigated using Response Surface Methodology in the muscles separately and together and predictive models reported. Results show that to assess the relationship between the changes of thickness and activity (EMG) in muscles, we can use quadratic model for the rectus femoris, tibialis anterior, transverse abdominal, biceps brachii and brachialis muscles (R(2)=0.624-0.891) and linear model for the internal and external oblique abdominal, lumbar multifidus and deep cervical flexor muscles (R(2)=0.348-0.767). Due to the high correlation coefficient for the equations in the bulky muscles, it seems that the correlation between EMG RMS and ultrasound data of muscle thickness on the bulky muscles is higher than the flat muscles. This relationship may depend more on the type of activity than the type of muscle.

  12. Acute changes in kinematic and muscle activity patterns in habitually shod rearfoot strikers while running barefoot.

    PubMed

    Strauts, Janina; Vanicek, Natalie; Halaki, Mark

    2016-01-01

    The aim of this study was to observe changes in the kinematics and muscle activities when barefoot running was initially adopted by six habitually shod, recreational rearfoot striking runners. Participants ran on a treadmill shod for 5 min, completed 3 × 10-min intervals of barefoot running and then completed a final minute of shod running at a self-selected pace. Dependent variables (speed, joint angles at foot-contact, joint range of motion (ROM), mean and peak electromyography (EMG) activity) were compared across conditions using repeated measures ANOVAs. Anterior pelvic tilt and hip flexion significantly decreased during barefoot conditions at foot contact. The ROM for the trunk, pelvis, knee and ankle angles decreased during the barefoot conditions. Mean EMG activity was reduced for biceps femoris, gastrocnemius lateralis and tibialis anterior during barefoot running. The peak activity across the running cycle decreased in biceps femoris, vastus medialis, gastrocnemius medialis and tibialis anterior during barefoot running. During barefoot running, tibialis anterior activity significantly decreased during the pre-activation and initial contact phases; gastrocnemius lateralis and medialis activity significantly decreased during the push-off phase. Barefoot running caused immediate biomechanical and neuromuscular adaptations at the hip and pelvis, which persisted when the runners donned their shoes, indicating that some learning had occurred during an initial short bout of barefoot running.

  13. The influence of different footwear on 3-D kinematics and muscle activation during the barbell back squat in males.

    PubMed

    Sinclair, Jonathan; McCarthy, Derek; Bentley, Ian; Hurst, Howard Thomas; Atkins, Stephen

    2015-01-01

    The barbell back squat is commonly used by athletes participating in resistance training. The barbell squat is typically performed using standard athletic shoes, or specially designed weightlifting footwear, although there are now a large number of athletes who prefer to squat barefoot or in barefoot-inspired footwear. This study aimed to determine how these footwear influence 3-D kinematics and muscle activation potentials during the barbell back squat. Fourteen experienced male participants completed squats at 70% 1 rep max in each footwear condition. 3-D kinematics from the torso, hip, knee and ankle were measured using an eight-camera motion analysis system. In addition, electromyographical (EMG) measurements were obtained from the rectus femoris, tibialis anterior, gastrocnemius, erector spinae and biceps femoris muscles. EMG parameters and joint kinematics were compared between footwear using repeated-measures analyses of variance. Participants were also asked to subjectively rate which footwear they preferred when performing their squat lifts; this was examined a chi-squared test. The kinematic analysis indicated that, in comparison to barefoot the running shoe was associated with increased squat depth, knee flexion and rectus femoris activation. The chi-squared test was significant and showed that participants preferred to squat barefoot. This study supports anecdotal evidence of athletes who prefer to train barefoot or in barefoot-inspired footwear although no biomechanical evidence was found to support this notion.

  14. Peak Muscle Activation, Joint Kinematics, and Kinetics during Elliptical and Stepping Movement Pattern on a Precor Adaptive Motion Trainer

    ERIC Educational Resources Information Center

    Rogatzki, Matthew J.; Kernozek, Thomas W.; Willson, John D.; Greany, John F.; Hong, Di-An; Porcari, John P.

    2012-01-01

    Kinematic, kinetic, and electromyography data were collected from the biceps femoris, rectus femoris (RF), gluteus maximus, and erector spinae (ES) during a step and elliptical exercise at a standardized workload with no hand use. Findings depicted 95% greater ankle plantar flexion (p = 0.01), 29% more knee extension (p = 0.003), 101% higher peak…

  15. Intra-session repeatability of lower limb muscles activation pattern during pedaling.

    PubMed

    Dorel, Sylvain; Couturier, Antoine; Hug, François

    2008-10-01

    Assessment of intra-session repeatability of muscle activation pattern is of considerable relevance for research settings, especially when used to determine changes over time. However, the repeatability of lower limb muscles activation pattern during pedaling is not fully established. Thus, we tested the intra-session repeatability of the activation pattern of 10 lower limb muscles during a sub-maximal cycling exercise. Eleven triathletes participated to this study. The experimental session consisted in a reference sub-maximal cycling exercise (i.e. 150 W) performed before and after a 53-min simulated training session (mean power output=200+/-12 W). Repeatability of EMG patterns was assessed in terms of muscle activity level (i.e. RMS of the mean pedaling cycle and burst) and muscle activation timing (i.e. onset and offset of the EMG burst) for the 10 following lower limb muscles: gluteus maximus (GMax), semimembranosus (SM), Biceps femoris (BF), vastus medialis (VM), rectus femoris (RF), vastus lateralis (VL), gastrocnemius medianus (GM) and lateralis (GL), soleus (SOL) and tibialis anterior (TA). No significant differences concerning the muscle activation level were found between test and retest for all the muscles investigated. Only VM, SOL and TA showed significant differences in muscle activation timing parameters. Whereas ICC and SEM values confirmed this weak repeatability, cross-correlation coefficients suggest a good repeatability of the activation timing parameters for all the studied muscles. Overall, the main finding of this work is the good repeatability of the EMG pattern during pedaling both in term of muscle activity level and muscle activation timing.

  16. Bridge Tenodesis: A Secure Fixation Technique for Biceps Long Head Tendinopathy During Arthroscopic Rotator Cuff Repair Using a Suture-Bridge Technique.

    PubMed

    Park, Jin-Young; Lee, Jae-Hyung; Oh, Kyung-Soo; Chung, Seok-Won; Bang, Jin-Young; Noh, Young-Min

    2016-10-01

    Tendinopathy of the long head of the biceps is often found as an intra-articular pathology in the glenohumeral joint. Because long head of the biceps lesions are common, surgical intervention to properly manage the long head of the biceps has become an important issue. Both tenodesis and tenotomy have been shown to provide benefits in biceps long head tendinopathy. But because of concerns about muscle power reduction, cramping, and "Popeye's deformity," which may result from biceps tenotomy, biceps tenodesis is a good option for treating biceps lesions. Here, we describe a time-saving, simple, and secure biceps tenodesis method during rotator cuff repairs, which is a combination of an adjacent soft-tissue tenodesis and a bony suprapectoral tenodesis, by performing a combined tenodesis (soft + bony), and we believe that the shoulder joint will gain more strength and loosening complications will be reduced.

  17. Assessment of Muscle Contractile Properties at Acute Moderate Altitude Through Tensiomyography.

    PubMed

    Morales-Artacho, Antonio J; Padial, Paulino; Rodríguez-Matoso, Dario; Rodríguez-Ruiz, David; García-Ramos, Amador; García-Manso, Juan Manuel; Calderón, Carmen; Feriche, Belén

    2015-12-01

    Under hypoxia, alterations in muscle contractile properties and faster fatigue development have been reported. This study investigated the efficacy of tensiomyography (TMG) in assessing muscle contractile function at acute moderate altitude. Biceps femoris (BF) and vastus lateralis (VL) muscles of 18 athletes (age 20.1 ± 6.1 years; body mass 65.4 ± 13.9 kg; height 174.6 ± 9.5 cm) were assessed at sea level and moderate altitude using electrically evoked contractions on two consecutive days. Maximum radial displacement (Dm), time of contraction (Tc), reaction time (Td), sustained contraction time (Ts), and relaxation time (Tr) were recorded at 40, 60, 80, and 100 mA. At altitude, VL showed lower Dm values at 40 mA (p = 0.008; ES = -0.237). Biceps femoris showed Dm decrements in all electrical stimulations (p < 0.001, ES > 0.61). In VL, Tc was longer at altitude at 40 (p = 0.031, ES = 0.56), and 100 mA (p = 0.03, ES = 0.51). Regarding Td, VL showed significant increases in all electrical intensities under hypoxia (p ≤ 0.03, ES ≥ 0.33). TMG appears effective at detecting slight changes in the muscle contractile properties at moderate altitude. Further research involving TMG along with other muscle function assessment methods is needed to provide additional insight into peripheral neuromuscular alterations at moderate altitude.

  18. Muscle activation patterns during walking from transtibial amputees recorded within the residual limb-prosthetic interface

    PubMed Central

    2012-01-01

    Background Powered lower limb prostheses could be more functional if they had access to feedforward control signals from the user’s nervous system. Myoelectric signals are one potential control source. The purpose of this study was to determine if muscle activation signals could be recorded from residual lower limb muscles within the prosthetic socket-limb interface during walking. Methods We recorded surface electromyography from three lower leg muscles (tibilias anterior, gastrocnemius medial head, gastrocnemius lateral head) and four upper leg muscles (vastus lateralis, rectus femoris, biceps femoris, and gluteus medius) of 12 unilateral transtibial amputee subjects and 12 non-amputee subjects during treadmill walking at 0.7, 1.0, 1.3, and 1.6 m/s. Muscle signals were recorded from the amputated leg of amputee subjects and the right leg of control subjects. For amputee subjects, lower leg muscle signals were recorded from within the limb-socket interface and from muscles above the knee. We quantified differences in the muscle activation profile between amputee and control groups during treadmill walking using cross-correlation analyses. We also assessed the step-to-step inter-subject variability of these profiles by calculating variance-to-signal ratios. Results We found that amputee subjects demonstrated reliable muscle recruitment signals from residual lower leg muscles recorded within the prosthetic socket during walking, which were locked to particular phases of the gait cycle. However, muscle activation profile variability was higher for amputee subjects than for control subjects. Conclusion Robotic lower limb prostheses could use myoelectric signals recorded from surface electrodes within the socket-limb interface to derive feedforward commands from the amputee’s nervous system. PMID:22882763

  19. Muscle reaction function of individuals with intellectual disabilities may be improved through therapeutic use of a horse.

    PubMed

    Giagazoglou, Paraskevi; Arabatzi, Fotini; Kellis, Eleftherios; Liga, Maria; Karra, Chrisanthi; Amiridis, Ioannis

    2013-09-01

    Reaction time and muscle activation deficits might limit the individual's autonomy in activities of daily living and in participating in recreational activities. The aim of the present study was to assess the effects of a 14-week hippotherapy exercise program on movement reaction time and muscle activation in adolescents with intellectual disability (ID). Nineteen adolescents with moderate ID were assigned either to an experimental group (n=10) or a control group (n=9). The experimental group attended a hippotherapy exercise program, consisting of two 30-min sessions per week for 14 weeks. Reaction time, time of maximum muscle activity and electromyographic activity (EMG) of rectus femoris and biceps femoris when standing up from a chair under three conditions: in response to audio, visual and audio with closed eyes stimuli were measured. Analysis of variance designs showed that hippotherapy intervention program resulted in significant improvements in reaction time and a reduction in time to maximum muscle activity of the intervention group comparing to the control group in all 3 three conditions that were examined (p<0.05). The present findings suggest that the muscle reaction function of individuals with ID can be improved through hippotherapy training. Hippotherapy probably creates a changing environment with a variety of stimuli that enhance deep proprioception as well as other sensory inputs. In conclusion, this study provides evidence that hippotherapy can improve functional task performance by enhancing reaction time.

  20. BICEP2 constrains composite inflation

    NASA Astrophysics Data System (ADS)

    Channuie, Phongpichit

    2014-07-01

    In light of BICEP2, we re-examine single field inflationary models in which the inflation is a composite state stemming from various four-dimensional strongly coupled theories. We study in the Einstein frame a set of cosmological parameters, the primordial spectral index ns and tensor-to-scalar ratio r, predicted by such models. We confront the predicted results with the joint Planck data, and with the recent BICEP2 data. We constrain the number of e-foldings for composite models of inflation in order to obtain a successful inflation. We find that the minimal composite inflationary model is fully consistent with the Planck data. However it is in tension with the recent BICEP2 data. The observables predicted by the glueball inflationary model can be consistent with both Planck and BICEP2 contours if a suitable number of e-foldings are chosen. Surprisingly, the super Yang-Mills inflationary prediction is significantly consistent with the Planck and BICEP2 observations.

  1. Tenderization potential of Hanwoo beef muscles from carcasses with differed genders and loin intramuscular fat content levels during post mortem ageing.

    PubMed

    Park, Beom Young; Seong, Pil Nam; Ba, Hoa Van; Park, Kyoung Mi; Cho, Soo Hyun; Moon, Sung Sil; Kang, Geun Ho

    2015-06-01

    Carcasses from Hanwoo steers (n = 15) and cows (n = 15) were classified into three groups: group 1 (G1), the carcasses had 10% to < 11.5% intramuscular fat (IMF) in loin muscles; group 2 (G2), the carcasses had 13% to < 4.5% IMF in loin muscles; and group 3(G3), the carcasses had 17% to < 18.5% IMF in loin muscles. These were used to evaluate the effects of gender and carcass group on quality traits and Warner-Bratzler shear force (WBSF) of Psoas major (PM), Longissimus thoracis (LT), Longissimus lumborum (LL), Longus colli (LC), Supraspinatus (SS), Latissimus dorsi (LAD), Semimembranosus (SM), Quadriceps femoris (QF), Biceps femoris (BF) and Semitendinosus (ST) muscles. Our results showed that pH values of LT, LL, LC, BF and QF muscles were lower in steers than in cows (P < 0.05). Water holding capacity (WHC) was found higher in LC, SS, LAD and QF muscles of steers (P < 0.05). At day 2 of ageing, gender affected the WBSF values of only PM, LD and QF muscles in G1, and QF muscle in G3; however, with additional ageing, the gender effect was observed for most of the muscles. Most muscles showed ageing responses; however, the rates of ageing response significantly varied depending on gender and carcass groups. The muscles of G1 and G2 had generally higher tenderization potentials than those of G3. Furthermore, most muscles in G3 had generally lower WBSF values than in G1 and G2. These results clearly indicate that ageing has a significant effect on quality and WBSF of beef muscles, and the classification by loin IMF level may be useful for prediction of the tenderness of other muscles.

  2. Is interindividual variability of EMG patterns in trained cyclists related to different muscle synergies?

    PubMed

    Hug, François; Turpin, Nicolas A; Guével, Arnaud; Dorel, Sylvain

    2010-06-01

    Our aim was to determine whether muscle synergies are similar across trained cyclists (and thus whether the same locomotor strategies for pedaling are used), despite interindividual variability of individual EMG patterns. Nine trained cyclists were tested during a constant-load pedaling exercise performed at 80% of maximal power. Surface EMG signals were measured in 10 lower limb muscles. A decomposition algorithm (nonnegative matrix factorization) was applied to a set of 40 consecutive pedaling cycles to differentiate muscle synergies. We selected the least number of synergies that provided 90% of the variance accounted for VAF. Using this criterion, three synergies were identified for all of the subjects, accounting for 93.5+/-2.0% of total VAF, with VAF for individual muscles ranging from 89.9+/-8.2% to 96.6+/-1.3%. Each of these synergies was quite similar across all subjects, with a high mean correlation coefficient for synergy activation coefficients (0.927+/-0.070, 0.930+/-0.052, and 0.877+/-0.110 for synergies 1-3, respectively) and muscle synergy vectors (0.873+/-0.120, 0.948+/-0.274, and 0.885+/-0.129 for synergies 1-3, respectively). Despite a large consistency across subjects in the weighting of several monoarticular muscles into muscle synergy vectors, we found larger interindividual variability for another monoarticular muscle (soleus) and for biarticular muscles (rectus femoris, gastrocnemius lateralis, biceps femoris, and semimembranosus). This study demonstrated that pedaling is accomplished by the combination of the similar three muscle synergies among trained cyclists. The interindividual variability of EMG patterns observed during pedaling does not represent differences in the locomotor strategy for pedaling.

  3. Evaluation of muscle injury using magnetic resonance imaging

    NASA Technical Reports Server (NTRS)

    LeBlanc, A. D.; Jaweed, M.; Evans, H.

    1993-01-01

    The objective of this study was to investigate spin echo T2 relaxation time changes in thigh muscles after intense eccentric exercise in healthy men. Spin echo and calculated T2 relaxation time images of the thighs were obtained on several occasions after exercise of one limb; the contralateral limb served as control. Muscle damage was verified by elevated levels of serum creatine kinase (CK). Thirty percent of the time no exercise effect was discernible on the magnetic resonance (MR) images. In all positive MR images (70%) the semitendinosus muscle was positive, while the biceps femoris, short head, and gracilis muscles were also positive in 50% and 25% of the total cases, respectively. The peak T2 relaxation time and serum CK were correlated (r = 0.94, p<0.01); temporal changes in muscle T2 relaxation time and serum CK were similar, although T2 relaxation time remained positive after serum CK returned to background levels. We conclude that magnetic resonance imaging can serve as a useful tool in the evaluation of eccentric exercise muscle damage by providing a quantitative indicator of damage and its resolution as well as the specific areas and muscles.

  4. Effect of muscle and post-mortem rate of pH and temperature fall on antioxidant enzyme activities in beef.

    PubMed

    Pastsart, Umaporn; De Boever, Maarten; Claeys, Erik; De Smet, Stefaan

    2013-03-01

    The aim of this study was to investigate the effect of muscle, inner and outer Musculus biceps femoris (IBF and OBF respectively) and Musculus longissimus dorsi (LD), on the post-mortem rate of pH and temperature fall, and the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) during simulated retail display. At day 0 of display (2 days post-mortem), the CAT and GSH-Px activities were lower in IBF than in OBF and LD (P<0.001), and the SOD activity was lower in OBF compared to IBF and LD (P<0.001). At day 10 of display, SOD and CAT activities had decreased in all three muscles compared to day 0 (P<0.001), whereas the GSH-Px activity did increase with time of display. Across muscles, there were significant relationships between temperature fall, colour, lipid and colour stability and antioxidant enzyme activities.

  5. Proximal Biceps in Overhead Athletes.

    PubMed

    Chalmers, Peter N; Verma, Nikhil N

    2016-01-01

    The proximal long head of the biceps tendon and its attachment at the superior glenoid tubercle and labrum are subject to a spectrum of disorders in overhead athletes. Biceps disorders are commonly characterized by intermittent anterior or deep-seated shoulder pain exacerbated by activity. Diagnosis is reached via various physical examination maneuvers; MRI can be uncertain. Nonsteroidal anti-inflammatory medications, targeted ultrasound-guided corticosteroid injections, and supervised physical therapy are the mainstays of nonoperative treatment. Operative treatment, which remains controversial, provides reliable pain relief, restoration of function for activities of daily living, and low complication rates, but return to play can be unpredictable.

  6. Recruitment and Decruitment of Motor Units Activities of M. Biceps Brachii During Isovelocity Movements

    DTIC Science & Technology

    2001-10-25

    haviors of motor units of m. biceps brachii (biceps short head muscle) during flexion movements in wide range of elbow joint angle. In this study, eight...range (from 0 [deg] to 120 [deg]) of elbow joint angle with a surface electrode array. We identified ac- tion potensials of each moitor unit and...ing flexion movements in wide range of elbow joint angle. In this study, eight surface electromyograms (EMGs) were measured during flexion movements

  7. Bilateral Congenital Agenesis of the Long Head of the Biceps Tendon: The Beginning

    PubMed Central

    Rego Costa, Francisco; Esteves, Cátia; Melão, Lina

    2016-01-01

    The biceps brachii muscle is prone to variants but absence of the long head of the biceps (LHB) tendon is an exceptionally rare anomaly. This report concerns the fourth case of bilateral congenital absence of the LHB tendon and presents the ultrasonography (US) and magnetic resonance (MR) findings. Our case has the peculiarity of being the first in which bilateral LHB tendon agenesis is not associated with rotator cuff or labral tears. PMID:26904345

  8. Changes in muscle activation patterns in response to enhanced sensory input during treadmill stepping in infants born with myelomeningocele

    PubMed Central

    Pantall, Annette; Teulier, Caroline; Ulrich, Beverly D.

    2013-01-01

    Infants with myelomeningocele (MMC) increase step frequency in response to modifications to the treadmill surface. The aim was to investigate how these modifications impacted the electromyographic (EMG) patterns. We analyzed EMG from 19 infants aged 2–10 months, with MMC at the lumbosacral level. We supported infants upright on the treadmill for 12 trials, each 30 seconds long. Modifications included visual flow, unloading, weights, Velcro and lcriction. Surface electrodes recorded EMG from tibialis anterior, lateral gastrocnemius, rectus femoris and biceps femoris. We determined muscle bursts for each stride cycle and from these calculated various parameters. Results indicated that each of the five sensory conditions generated different motor patterns. Visual flow and friction which we previously reported increased step frequency impacted lateral gastrocnemius most. Weights, which significantly decreased step frequency increased burst duration and co-activity of the proximal muscles. We also observed an age effect, with all conditions increasing muscle activity in younger infants whereas in older infants visual flow and unloading stimulated most activity. In conclusion, we have demonstrated that infants with myelomeningocele at levels which impact the myotomes of major locomotor muscles find ways to respond and adapt their motor output to changes in sensory input. PMID:23158017

  9. Relationship between socket pressure and EMG of two muscles in trans-femoral stumps during gait.

    PubMed

    Hong, Jung Hwa; Mun, Mu Seong

    2005-04-01

    The biomechanical interaction between the leg stump and the prosthetic socket is critical in achieving close-to-normal ambulation. Although many investigations have been performed to understand the biomechanics of trans-tibial sockets, few studies have measured the socket interface pressure for transfemoral amputees. Furthermore, no report has examined how the residual muscle activities in the transfemoral stump affect the socket interface pressure characteristics during gait. In this study, an experimental method was developed to measure the trans-femoral socket interface pressures and EMG of muscles in the stumps of two trans-femoral amputees. Also, the measurement of three-dimensional prosthetic locomotion was synchronized to understand detailed socket biomechanics. Based on the experimental results, a significant correlation (P < 0.05) was found between the measured temporal EMG amplitude and the interface pressure at the knee flexor (biceps femoris) and extensor (rectus femoris). Therefore, the residual muscle activity of a trans-femoral amputee's stump could be an important factor affecting socket-interface pressure changes during ambulation.

  10. The effect of cycling on muscle activation in the running leg of an Olympic distance triathlon.

    PubMed

    Heiden, Tamika; Burnett, Angus

    2003-01-01

    The aim of this study was to determine the effect of prior cycling on EMG activity of selected lower leg muscles during running. Ten elite level triathletes underwent two testing sessions at race pace: a 40 km cycle followed by a 2 km run (CR) and a 10 km run followed by a 2 km run (RR). EMG data from selected lower limb muscles were collected at three sections of each run (0 km, 1 km and 2 km) for six strides using a portable data logger. Significant differences (p < 0.05) between condition were found for the level of activation (Lact) for biceps femoris (BF) during stance and vastus lateralis (VL) during flight and stance. Vastus medialis (VM) changed in Lact, during flight, between sections in the 2 km run. Furthermore, significant differences (p < 0.05) between condition were found for BF during stance and for rectus femoris (RF) and VM during flight. There was a significant difference (p < 0.05) in the duration of VL activation (Dact) across sections of the 2 km run. Findings from this investigation highlight changes in muscle function when changing from cycling to running and indicate a need to train specifically for the cycle to run transition. Such training may improve performance and reduce the risk of injury.

  11. The effects of a pelvic belt on trunk and lower extremity muscles in the bridge position

    PubMed Central

    Cha, Hyun-Gyu; Wu, Yan-Ting; Kim, Myoung-Kwon

    2016-01-01

    [Purpose] The purpose of this study was to investigate the effects of a pelvic belt on the activities of trunk and lower extremity muscles in normal adults. [Subjects and Methods] The subjects were 20 normal individuals without a history of orthopedic problems. The pelvic compression belt (The Com-Pressor, OPTP, Minneapolis, MN, USA) was an adjustable body belt with four elastic compression bands that provide stabilizing pressure and was designed to adjust the amount of force applied and to alter sites of compression. The body belt was placed below the anterior superior iliac spine, and stabilizing pressure was applied to the belt using the elastic compression bands in the bridge position after confirming the site of compression. [Results] The subjects showed a significant decrease in muscle activation in the erector spinae, oblique internus abdominis, rectus femoris, and biceps femoris while wearing the pelvic belt. [Conclusion] The use of a pelvic compression belt with external pelvic compression might improve pelvic joint stability and alter neuromotor control of the lumbopelvic and thigh muscles. PMID:28174437

  12. Progressive muscle proteome changes in a clinically relevant pig model of Duchenne muscular dystrophy

    PubMed Central

    Fröhlich, Thomas; Kemter, Elisabeth; Flenkenthaler, Florian; Klymiuk, Nikolai; Otte, Kathrin A.; Blutke, Andreas; Krause, Sabine; Walter, Maggie C.; Wanke, Rüdiger; Wolf, Eckhard; Arnold, Georg J.

    2016-01-01

    Duchenne muscular dystrophy (DMD) is caused by genetic deficiency of dystrophin and characterized by massive structural and functional changes of skeletal muscle tissue, leading to terminal muscle failure. We recently generated a novel genetically engineered pig model reflecting pathological hallmarks of human DMD better than the widely used mdx mouse. To get insight into the hierarchy of molecular derangements during DMD progression, we performed a proteome analysis of biceps femoris muscle samples from 2-day-old and 3-month-old DMD and wild-type (WT) pigs. The extent of proteome changes in DMD vs. WT muscle increased markedly with age, reflecting progression of the pathological changes. In 3-month-old DMD muscle, proteins related to muscle repair such as vimentin, nestin, desmin and tenascin C were found to be increased, whereas a large number of respiratory chain proteins were decreased in abundance in DMD muscle, indicating serious disturbances in aerobic energy production and a reduction of functional muscle tissue. The combination of proteome data for fiber type specific myosin heavy chain proteins and immunohistochemistry showed preferential degeneration of fast-twitch fiber types in DMD muscle. The stage-specific proteome changes detected in this large animal model of clinically severe muscular dystrophy provide novel molecular readouts for future treatment trials. PMID:27634466

  13. Simultaneous bilateral distal biceps tendon repair: case report.

    PubMed

    Storti, Thiago Medeiros; Paniago, Alexandre Firmino; Faria, Rafael Salomon Silva

    2017-01-01

    Simultaneous bilateral rupture of the distal biceps tendon is a rare clinical entity, seldom reported in the literature and with unclear therapeutic setting. The authors report the case of a 39-year-old white man who suffered a simultaneous bilateral rupture while working out. When weightlifting with elbows at 90° of flexion, he suddenly felt pain on the anterior aspect of the arms, coming for evaluation after two days. He presented bulging contour of the biceps muscle belly and ecchymosis in the antecubital fossa, extending distally to the medial aspect of the forearm, as well as a marked decrease of supination strength and pain in active elbow flexion. MRI confirmed the rupture with retraction of the distal biceps bilaterally. The authors opted for performing the tendon repairs simultaneously through the double incision technique and fixation to the bicipital tuberosity with anchors. The patient progressed quite well, with full return to labor and sports activities, being satisfied with the result after two years of surgery. In the literature search, few reports of simultaneous bilateral rupture of the distal biceps were retrieved, with only one treated in the acute phase of injury. Therefore, the authors consider this procedure to be a good option to solve this complex condition.

  14. The effect of swinging the arms on muscle activation and production of leg force during ski skating at different skiing speeds.

    PubMed

    Göpfert, Caroline; Lindinger, Stefan J; Ohtonen, Olli; Rapp, Walter; Müller, Erich; Linnamo, Vesa

    2016-06-01

    The study investigated the effects of arm swing during leg push-off in V2-alternate/G4 skating on neuromuscular activation and force production by the leg muscles. Nine skilled cross-country skiers performed V2-alternate skating without poles at moderate, high, and maximal speeds, both with free (SWING) and restricted arm swing (NOSWING). Maximal speed was 5% greater in SWING (P<0.01), while neuromuscular activation and produced forces did not differ between techniques. At both moderate and high speed the maximal (2% and 5%, respectively) and average (both 5%) vertical force and associated impulse (10% and 14%) were greater with SWING (all P<0.05). At high speed range of motion and angular velocity of knee flexion were 24% greater with SWING (both P<0.05), while average EMG of m. biceps femoris was 31% lower (all P<0.05) in SWING. In a similar manner, the average EMG of m. vastus medialis and m. biceps femoris were lower (17% and 32%, P<0.05) during the following knee extension. Thus, swinging the arms while performing V2-alternate can enhance both maximal speed and skiing economy at moderate and, in particularly, high speeds.

  15. The variability of co-activation pattern of antagonist muscles in human infant crawling.

    PubMed

    Xiong, Qi L; Wu, Xiao Y; Nong Xiao; Zeng, Si Y; Zheng, Xiao L; Di Wu; Hou, Wen S

    2016-08-01

    Infant crawling is part of normal human gross motor development, and a 4-beat gait that involves rhythmical flexion and extension of limbs and the underlying muscle co-activation of antagonist muscle around the joint. However, detection the co-activation pattern of antagonist muscle are sparse due to the general difficulty of measuring locomotion in human infants. In this paper, sEMG of antagonist muscles and the corresponding kinematics data of limbs were collected when infants were crawling on hands and knees at their self-selected speed. The infant's gross motor developmental status was assessed by the global Gross Motor Function Measure Scale (GMFM-88) as well. The method based on EMG-EMG plots was used to quantify the variability of co-activation pattern of antagonist muscle. After that, we observed that antagonist muscles of upper limb (triceps brachii and biceps brachii) showed less variability of co-activation pattern of muscles than lower limb(quadriceps femoris and hamstrings) during crawling, and this variability was also varied in different crawling phases (stance and swing). Furthermore, we found some varied behaviors in the co-activation patterns of antagonist muscles when gross motor developmental level increased. The preliminary work suggests that such adaptive changes may be related to the adjustment of neuromuscular in the early stage of gross motor development.

  16. The effect of a vastus lateralis tape on muscle activity during stair climbing.

    PubMed

    McCarthy Persson, U; Fleming, H F; Caulfield, B

    2009-06-01

    Recently taping techniques with the primary purpose of altering muscle activity have become a part of clinical physiotherapy practice. A firmly applied tape across the fibres of the vastus lateralis (VL) muscle has been proposed to decrease the VL muscle activity. The primary aim of this study was to assess the effects of an inhibitory muscle tape applied over the vastus lateralis (VL) muscle during stair climbing. Twenty five subjects without lower limb pathology were recruited. Normalised integrated EMG (IEMG) was analysed from VL, vastus medialis obliquus (VMO), biceps femoris (BF) and soleus muscles during stair climbing. The subjects were assessed during three conditions: no tape (untaped), (no tension) control tape and (tensioned tape) VL inhibitory taping application. There was a significant decrease (p<0.05) in the VL IEMG during the initial stance phase during both stair ascent and descent. The inhibition if the VL muscle occurred with both control and VL inhibitory tape applied. No significant differences (p>0.05) were noted in any of the other muscles assessed. The results demonstrated that there was a significant decrease in the IEMG of the VL both during stair ascent and descent with VL inhibitory tape and control tape applied in normal subjects.

  17. Molecular characterization and expression patterns of Lbx1 in porcine skeletal muscle.

    PubMed

    Chao, Zhe; Wu, Jian; Zheng, Rong; Li, Feng-E; Xiong, Yuan-Zhu; Deng, Chang-Yan

    2011-08-01

    Ladybird-like genes were recently identified in mammals. The first member characterized, Lbx1, is expressed in developing skeletal muscle and the nervous system. However, little is known about the porcine Lbx1 gene. In the present study, we cloned and characterized Lbx1 from porcine muscle. RT-PCR analyses showed that Lbx1 was highly expressed in porcine skeletal muscle tissues. And we provide the first evidence that Lbx1 has a certain regulated expression pattern during the postnatal period of the porcine skeletal muscle development. Lbx1 gene expressed at higher levels in biceps femoris muscles compared with masseter, semitendinosus and longissimus dorsi muscles in Meishan pigs. Phylogenetic tree was constructed by aligning the amino acid sequences of different species. Moreover, single nucleotide polymorphism (SNP) scanning in the Lbx1 genomic fragment identified two mutations, g.752A>G and g.-1559C>G. Association analysis in our experimental pig populations showed that the mutation of g.752A>G was significantly associated with loin muscle area (P<0.05) and internal fat rate (P<0.05). Our results suggest that the Lbx1 gene might be a candidate gene of carcass traits and provide useful information for further studies on its roles in porcine skeletal muscle.

  18. Voluntary activation of biceps-to-triceps and deltoid-to-triceps transfers in quadriplegia

    PubMed Central

    Peterson, Carrie L.; Bednar, Michael S.; Bryden, Anne M.; Keith, Michael W.; Perreault, Eric J.; Murray, Wendy M.

    2017-01-01

    The biceps or the posterior deltoid can be transferred to improve elbow extension function for many individuals with C5 or C6 quadriplegia. Maximum strength after elbow reconstruction is variable; the patient’s ability to voluntarily activate the transferred muscle to extend the elbow may contribute to the variability. We compared voluntary activation during maximum isometric elbow extension following biceps transfer (n = 5) and deltoid transfer (n = 6) in three functional postures. Voluntary activation was computed as the elbow extension moment generated during maximum voluntary effort divided by the moment generated with full activation, which was estimated via electrical stimulation. Voluntary activation was on average 96% after biceps transfer and not affected by posture. Individuals with deltoid transfer demonstrated deficits in voluntary activation, which differed by posture (80% in horizontal plane, 69% in overhead reach, and 70% in weight-relief), suggesting inadequate motor re-education after deltoid transfer. Overall, individuals with a biceps transfer better activated their transferred muscle than those with a deltoid transfer. This difference in neural control augmented the greater force-generating capacity of the biceps leading to increased elbow extension strength after biceps transfer (average 9.37 N-m across postures) relative to deltoid transfer (average 2.76 N-m across postures) in our study cohort. PMID:28253262

  19. BICEP2 III: Instrumental systematics

    SciTech Connect

    Ade, P. A. R.

    2015-11-23

    In a companion paper, we have reported a >5σ detection of degree scale B-mode polarization at 150 GHz by the Bicep2 experiment. Here we provide a detailed study of potential instrumental systematic contamination to that measurement. We focus extensively on spurious polarization that can potentially arise from beam imperfections. We present a heuristic classification of beam imperfections according to their symmetries and uniformities, and discuss how resulting contamination adds or cancels in maps that combine observations made at multiple orientations of the telescope about its boresight axis. We introduce a technique, which we call "deprojection," for filtering the leading order beam-induced contamination from time-ordered data, and show that it reduces power in Bicep2's actual and null-test BB spectra consistent with predictions using high signal-to-noise beam shape measurements. We detail the simulation pipeline that we use to directly simulate instrumental systematics and the calibration data used as input to that pipeline. Finally, we present the constraints on BB contamination from individual sources of potential systematics. We find that systematics contribute BB power that is a factor of ~10× below Bicep2's three-year statistical uncertainty, and negligible compared to the observed BB signal. Lastly, the contribution to the best-fit tensor/scalar ratio is at a level equivalent to r = (3–6) × 10–3.

  20. BICEP2 III: Instrumental systematics

    DOE PAGES

    Ade, P. A. R.

    2015-11-23

    In a companion paper, we have reported a >5σ detection of degree scale B-mode polarization at 150 GHz by the Bicep2 experiment. Here we provide a detailed study of potential instrumental systematic contamination to that measurement. We focus extensively on spurious polarization that can potentially arise from beam imperfections. We present a heuristic classification of beam imperfections according to their symmetries and uniformities, and discuss how resulting contamination adds or cancels in maps that combine observations made at multiple orientations of the telescope about its boresight axis. We introduce a technique, which we call "deprojection," for filtering the leading ordermore » beam-induced contamination from time-ordered data, and show that it reduces power in Bicep2's actual and null-test BB spectra consistent with predictions using high signal-to-noise beam shape measurements. We detail the simulation pipeline that we use to directly simulate instrumental systematics and the calibration data used as input to that pipeline. Finally, we present the constraints on BB contamination from individual sources of potential systematics. We find that systematics contribute BB power that is a factor of ~10× below Bicep2's three-year statistical uncertainty, and negligible compared to the observed BB signal. Lastly, the contribution to the best-fit tensor/scalar ratio is at a level equivalent to r = (3–6) × 10–3.« less

  1. Bicep2. III. INSTRUMENTAL SYSTEMATICS

    SciTech Connect

    Ade, P. A. R.; Aikin, R. W.; Bock, J. J.; Brevik, J. A.; Filippini, J. P.; Golwala, S. R.; Hildebrandt, S. R.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Buder, I.; Karkare, K. S.; Bullock, E.; Dowell, C. D.; Duband, L.; Fliescher, S.; Halpern, M.; Hasselfield, M.; Hilton, G. C.; Irwin, K. D.; Collaboration: Bicep2 Collaboration; and others

    2015-12-01

    In a companion paper, we have reported a >5σ detection of degree scale B-mode polarization at 150 GHz by the Bicep2 experiment. Here we provide a detailed study of potential instrumental systematic contamination to that measurement. We focus extensively on spurious polarization that can potentially arise from beam imperfections. We present a heuristic classification of beam imperfections according to their symmetries and uniformities, and discuss how resulting contamination adds or cancels in maps that combine observations made at multiple orientations of the telescope about its boresight axis. We introduce a technique, which we call “deprojection,” for filtering the leading order beam-induced contamination from time-ordered data, and show that it reduces power in Bicep2's actual and null-test BB spectra consistent with predictions using high signal-to-noise beam shape measurements. We detail the simulation pipeline that we use to directly simulate instrumental systematics and the calibration data used as input to that pipeline. Finally, we present the constraints on BB contamination from individual sources of potential systematics. We find that systematics contribute BB power that is a factor of ∼10× below Bicep2's three-year statistical uncertainty, and negligible compared to the observed BB signal. The contribution to the best-fit tensor/scalar ratio is at a level equivalent to r = (3–6) × 10{sup −3}.

  2. Muscle activity while running at 20%-50% of normal body weight.

    PubMed

    Mercer, John A; Applequist, Bryon C; Masumoto, Kenji

    2013-01-01

    Little information exists on how body weight (BW) support influences running biomechanics. The study aim was to determine how reducing BW by 50%-80% influences muscle activity while running at different speeds. Subjects (n = 7) ran at 100%, 115%, 125% of preferred speed at 100%, 50%, 40%, 30%, 20% of BW per speed. Average (AVG) electromyography of the rectified signal was compared (within subject design; 3-speeds × 5-BW, repeated measures ANOVAs; biceps femoris [BF], rectus femoris [RF], tibialis anterior [TA], gastrocnemius [GA]). RF, BF, and GA AVG were not influenced by BW-speed interaction (p > .05) and increased across speeds (p < .05). RF and GA AVG signal was reduced as BW was reduced (p < .05), but BF only tended to be different (p = .08). TA was influenced by BW-speed interaction (p < .05) with EMG decreasing across BW (p < .05) while increasing across speeds except at 100% BW. Overall, muscle activity increased with speed and decreased by BW reductions.

  3. An Acute Bout of Barefoot Running Alters Lower-limb Muscle Activation for Minimalist Shoe Users.

    PubMed

    Snow, N J; Basset, F A; Byrne, J

    2016-05-01

    Despite the abundance of barefoot running-related research, there have been no electromyography studies evaluating the effects of this mode of exercise on habitual users of minimalist footwear. The present study investigated differences in muscle activation during acute bouts of barefoot and shod running, in minimalist shoe users. 8 male participants ran on a motorized treadmill for 10 min under both conditions, at 70% maximal aerobic speed. Electromyographic data were sampled from the biceps femoris, gluteus maximus, gastrocnemius medialis, tibialis anterior, and vastus lateralis during both swing and stance. Root-mean-square analysis of electromyographic data was conducted to compare muscle activation between conditions. During stance, barefoot running resulted in greater muscle activity in gastrocnemius medialis and gluteus maximus, and lower muscle activity in tibialis anterior. During swing, barefoot running resulted in increased muscle activity in vastus lateralis and gastrocnemius medialus. These results indicate that, for minimalist shoe users, an acute bout of barefoot running results in significantly different lower-limb muscle activity. Increased activation in the above muscles presents a possible mechanism for injury, which should be considered during exercise prescription.

  4. Proximal humerus fracture after keyhole biceps tenodesis.

    PubMed

    Reiff, Stefanie N; Nho, Shane J; Romeo, Anthony A

    2010-07-01

    A biceps tenodesis is a common surgical procedure that is often carried out in conjunction with other surgical shoulder repairs to relieve biceps tendonitis. This case presents a 50-year-old woman who suffered a humerus fracture following an open keyhole biceps tenodesis. The potential reasons for the fracture as well as a brief analysis of the technique itself are presented. To our knowledge, this is the first case report of a humerus fracture following keyhole biceps tenodesis in the English-language literature.

  5. Proximal rectus femoris avulsion in an elite, olympic-level sprinter.

    PubMed

    Langer, Phillip R; Selesnick, Harlan

    2010-11-01

    Quadriceps injuries, ranging from simple strains to disabling muscle ruptures, are common athletic injuries. The rectus femoris is the most commonly injure portion of the quadriceps musculature. This article is, to our knowledge, the first report of a proximal rectus femoris avulsion in an elite, Olympic-level 100-meter sprinter, acutely managed with surgical repair. Several key factors must be considered and carefully assessed when determining the appropriate course of management (ie, deciding between operative and nonoperative treatment): amount of distal retraction of the tendon, severity of associated soft-tissue trauma, physical examination, and postoperative goals (eg, return to elite-level competitive sports involving running or kicking vs resuming basic activities of daily living). We believe that these factors in our elite, high-performance athlete dictated an operative course of management.

  6. The impact of altered task mechanics on timing and duration of eccentric bi-articular muscle contractions during cycling.

    PubMed

    Connick, Mark J; Li, François-Xavier

    2013-02-01

    In order to understand muscle adaptations to altered task mechanics during cycling, this study investigated the impact of altered seat height and cadence on timing and duration of gastrocnemius (GAST), biceps femoris (BF) and vastus lateralis (VL) eccentric contractions and muscle activation patterns, and cycling economy. Ten male cyclists completed 9 × 5 min of cycling at 3 seat heights and 3 cadences. Three-dimensional leg kinematics and muscle activation patterns were recorded to estimate timing of eccentric muscle contractions. Onset, offset and duration of eccentric contractions and, onset, offset and duration of muscle activation were calculated, along with cycling economy. Duration of GAST and VL eccentric contractions decreased with increasing seat height due to earlier offset of eccentric muscle contractions. Duration of BF eccentric contractions significantly increased with seat height due to a later eccentric contraction offset. Offset of GAST and BF muscle activation occurred earlier with increasing cadence. Cycling economy was significantly affected by cadence but not seat height. The results suggest that as a consequence of altered seat height, proprioceptive feedback is used to fine-tune the timing of bi-articular eccentric muscle contractions. These results may have implications for seat height self-selection.

  7. Interneurones in pathways from group II muscle afferents in sacral segments of the feline spinal cord.

    PubMed

    Jankowska, E; Riddell, J S

    1994-03-15

    1. Properties of dorsal horn interneurones that process information from group II muscle afferents in the sacral segments of the spinal cord have been investigated in the cat using both intracellular and extracellular recording. 2. The interneurones were excited by group II muscle afferents and cutaneous afferents but not by group I muscle afferents. They were most effectively excited by group II afferents of the posterior biceps, semitendinosus, triceps surae and quadriceps muscle nerves and by cutaneous afferents running in the cutaneous femoris, pudendal and sural nerves. The earliest synaptic actions were evoked monosynaptically and were very tightly locked to the stimuli. 3. EPSPs evoked monosynaptically by group II muscle afferents and cutaneous afferents of the most effective nerves were often cut short by disynaptic IPSPs. As a consequence of this negative feedback the EPSPs gave rise to single or double spike potentials and only a minority of interneurones responded with repetitive discharges. However, the neurones that did respond repetitively did so at a very high frequency of discharges (0.8-1.2 ms intervals between the first 2-3 spikes). 4. Sacral dorsal horn group II interneurones do not appear to act directly upon motoneurones because: (i) these interneurones are located outside the area within which last order interneurones have previously been found and (ii) the latencies of PSPs evoked in motoneurones by stimulation of the posterior biceps and semitendinosus, cutaneous femoris and pudendal nerves (i.e. the main nerves providing input to sacral interneurones) are compatible with a tri- but not with a disynaptic coupling. Spatial facilitation of EPSPs and IPSPs following synchronous stimulation of group II and cutaneous afferents of these nerves shows, however, that sacral interneurones may induce excitation or inhibition of motoneurones via other interneurones. 5. Comparison of the properties of group II interneurones in the sacral segments with

  8. Progression and variation of fatty infiltration of the thigh muscles in Duchenne muscular dystrophy, a muscle magnetic resonance imaging study.

    PubMed

    Li, Wenzhu; Zheng, Yiming; Zhang, Wei; Wang, Zhaoxia; Xiao, Jiangxi; Yuan, Yun

    2015-05-01

    The purpose of this study was to assess the progression and variation of fatty infiltration of the thigh muscles of Duchenne muscular dystrophy patients. Muscle magnetic resonance imaging was used to measure the degree of fatty infiltration of the thigh muscles of 171 boys with Duchenne muscular dystrophy (mean age, 6.09 ± 2.30 years). Fatty infiltration was assigned using a modified Mercuri's scale 0-5 (normal-severe). The gluteus maximus and adductor magnus were affected in patients less than two years old, followed by the biceps femoris. Quadriceps and semimembranosus were first affected at the age of five to six years; the sartorius, gracilis and adductor longus remained apparently unaffected until seven years of age. Fatty infiltration of all the thigh muscles developed rapidly after seven years of age. The standard deviation of the fatty infiltration scores ranged from 2.41 to 4.87 before five years old, and from 6.84 to 11.66 between six and ten years old. This study provides evidence of highly variable degrees of fatty infiltration in children of different ages with Duchenne muscular dystrophy, and indicates that fatty infiltration progresses more quickly after seven years of age. These findings may be beneficial for the selection of therapeutic regimens and the analysis of future clinical trials.

  9. Modulation of multisegmental monosynaptic responses in a variety of leg muscles during walking and running in humans.

    PubMed

    Courtine, Grégoire; Harkema, Susan J; Dy, Christine J; Gerasimenko, Yuri P; Dyhre-Poulsen, Poul

    2007-08-01

    Motor responses evoked by stimulating the spinal cord percutaneously between the T11 and T12 spinous processes were studied in eight human subjects during walking and running. Stimulation elicited responses bilaterally in the biceps femoris, vastus lateralis, rectus femoris, medial gastrocnemius, soleus, tibialis anterior, extensor digitorum brevis and flexor digitorum brevis. The evoked responses were consistent with activation of Ia afferent fibres through monosynaptic neural circuits since they were inhibited when a prior stimulus was given and during tendon vibration. Furthermore, the soleus motor responses were inhibited during the swing phase of walking as observed for the soleus H-reflex elicited by tibial nerve stimulation. Due to the anatomical site and the fibre composition of the peripheral nerves it is difficult to elicit H-reflex in leg muscles other than the soleus, especially during movement. In turn, the multisegmental monosynaptic responses (MMR) technique provides the opportunity to study modulation of monosynaptic reflexes for multiple muscles simultaneously. Phase-dependent modulation of the MMR amplitude throughout the duration of the gait cycle period was observed in all muscles studied. The MMR amplitude was large when the muscle was activated whereas it was generally reduced, or even suppressed, when the muscle was quiescent. However, during running, there was a systematic anticipatory increase in the amplitude of the MMR at the end of swing in all proximal and distal extensor muscles. The present findings therefore suggest that there is a general control scheme by which the transmission in the monosynaptic neural circuits is modulated in all leg muscles during stepping so as to meet the requirement of the motor task.

  10. Coupling of albumin flux to volume flow in skin and muscles of anesthetized rats

    SciTech Connect

    Renkin, E.M.; Gustafson-Sgro, M.; Sibley, L.

    1988-09-01

    Bovine serum albumin (BSA) labeled with /sup 131/I or /sup 125/I was injected intravenously in pentobarbital sodium-anesthetized rats, and tracer clearances into leg skin and muscles were measured over 30, 60, and 120 min. BSA labeled with the alternate tracer was used as vascular volume reference. Two minutes before injection of the tracer, a ligature was tied around one femoral vein to occlude outflow partially and raise capillary pressure in that leg. The unoccluded leg served as control. Skin and muscles of the occluded leg had variably and substantially higher water contents (delta W) than paired control tissues and slightly but consistently increased albumin clearances (CA). The delta CA/delta W, equivalent to the albumin concentration of capillary filtrate relative to plasma determined by linear regression, were as follows: leg skin 0.004 (95% confidence limits -0.001 to +0.009), muscle biceps femoris 0.005 (0.001-0.010), muscle gastrocnemius 0.011 (0.004-0.019), muscle tibialis anterior 0.016 (0.012-0.021). All these values are significantly less than 0.10, which corresponds to a reflection coefficient for serum albumin (sigma A) of 0.90. Convective coupling of albumin flux to volume flux in skin and muscles of intact, anesthetized rats is low, with sigma AS in the range 0.98 to greater than 0.99.

  11. Isometric squat force output and muscle activity in stable and unstable conditions.

    PubMed

    McBride, Jeffrey M; Cormie, Prue; Deane, Russell

    2006-11-01

    The purpose of this study was to assess the effect of stable vs. unstable conditions on force output and muscle activity during an isometric squat. Nine men involved in recreational resistance training participated in the investigation by completing a single testing session. Within this session subjects performed isometric squats either while standing directly on the force plate (stable condition, S) or while standing on inflatable balls placed on top of the force plate (unstable condition, U). Electromyography (EMG) was recorded during both conditions from the vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), and medial gastrocnemius (G) muscles. Results indicated peak force (PF) and rate of force development (RFD) were significantly lower, 45.6% and 40.5% respectively, in the U vs. S condition (p < or = 0.05). Average integrated EMG values for the VL and VM were significantly higher in the S vs. U condition. VL and VM muscle activity was 37.3% and 34.4% less in U in comparison to S. No significant differences were observed in muscle activity of the BF or G between U and S. The primary finding in this investigation is that isometric squatting in an unstable condition significantly reduces peak force, rate of force development, and agonist muscle activity with no change in antagonist or synergist muscle activity. In terms of providing a stimulus for strength gain no discernable benefit of performing a resistance exercise in an unstable condition was observed in the current study.

  12. FUNCTIONAL OUTCOMES AFTER DISTAL BICEPS BRACHII REPAIR: A CASE SERIES

    PubMed Central

    Morris, Tim; Otto, Charissa; Zerella, Tanisha; Semmler, John G; Human, Taaibos; Phadnis, Joideep; Bain, Gregory I

    2016-01-01

    Objectives To investigate outcomes after surgical repair of distal biceps tendon rupture and the influence of arm dominance on isokinetic flexion and supination results. Background/Purpose While relatively uncommon, rupture of the distal biceps tendon can result in significant strength deficits, for which surgical repair is recommended. The purpose of this study was to assess patient reported functional outcomes and muscle performance following surgery. Methods A sample of 23 participants (22 males, 1 female), who had previously undergone surgical repair of the distal biceps tendon, were re-examined at a minimum of one year after surgery. Biodex isokinetic elbow flexion and supination testing was performed to assess strength (as measured by peak torque) and endurance (as measured by total work and work fatigue). The Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) and Mayo Elbow Performance Scale (MEPS) were used to assess participants' subjectively reported functional recovery. Results At a mean of 7.6 years after surgical repair, there were no differences between the repaired and uninvolved elbows in peak torque (p = 0.47) or total work (p = 0.60) for flexion or supination. There was also no difference in elbow flexion work fatigue (p = 0.22). However, there was significantly less work fatigue in supination, which was likely influenced by arm dominance, as most repairs were to the dominant arm, F(1,22)=5.67, p = 0.03. Conclusion The long-term strength of the repaired elbow was similar to the uninvolved elbow after surgery to the distal biceps tendon. Endurance of the repaired elbow was similar in flexion but greater in supination, probably influenced by arm dominance. Study design Retrospective case series Level of Evidence Level 4 PMID:27904798

  13. Altered muscle coordination when pedaling with independent cranks

    PubMed Central

    Hug, François; Boumier, Florian; Dorel, Sylvain

    2013-01-01

    Pedaling with independent cranks ensures each leg cycles independently of the other, and thus eliminates the contribution of the contralateral leg during the upstroke phase. Consequently the subject is required to actively pull-up the pedal to complete the cycle. The present study aimed to determine the acute effect of the use of independent cranks on muscle coordination during a submaximal pedaling exercise. Ten healthy males were asked to perform submaximal pedaling exercises at 100 Watts with normal fixed cranks (control condition) or independent cranks. Both 2-D pedal forces and electromyographic (EMG) SIGNALS of 10 lower limb muscles were recorded. When the mean EMG activity across the cycle was considered, the use of independent cranks significantly increased the activity level compared to control for Tibialis anterior (TA) (P = 0.0017; +336 ± 302%), Gastrocnemius medialis (GM) (P = 0.0005; +47 ± 25%), Rectus femoris (RF) (P = 0.005; +123 ± 153%), Biceps femoris (BF)—long head (P = 0.0001; +162 ± 97%), Semimembranosus (SM) (P = 0.0001; +304 ± 192%), and Tensor fascia latae (P = 0.0001; +586 ± 262%). The analysis of the four pedaling sectors revealed that the increased activity of hip and knee flexors mainly occurred during the top dead center and the upstroke phase. In addition, a high inter-individual variability was found in the way the participants adapted to pedaling with independent cranks. The present results showed that the enforced pull-up action required when using independent cranks was achieved by increasing the activation of hip and knee flexors. Further studies are needed to determine whether training with independent cranks has the potential to induce long-term changes in muscle coordination, and, if so, whether these changes are beneficial for cycling performance. PMID:24009587

  14. Altered muscle coordination when pedaling with independent cranks.

    PubMed

    Hug, François; Boumier, Florian; Dorel, Sylvain

    2013-01-01

    Pedaling with independent cranks ensures each leg cycles independently of the other, and thus eliminates the contribution of the contralateral leg during the upstroke phase. Consequently the subject is required to actively pull-up the pedal to complete the cycle. The present study aimed to determine the acute effect of the use of independent cranks on muscle coordination during a submaximal pedaling exercise. Ten healthy males were asked to perform submaximal pedaling exercises at 100 Watts with normal fixed cranks (control condition) or independent cranks. Both 2-D pedal forces and electromyographic (EMG) SIGNALS of 10 lower limb muscles were recorded. When the mean EMG activity across the cycle was considered, the use of independent cranks significantly increased the activity level compared to control for Tibialis anterior (TA) (P = 0.0017; +336 ± 302%), Gastrocnemius medialis (GM) (P = 0.0005; +47 ± 25%), Rectus femoris (RF) (P = 0.005; +123 ± 153%), Biceps femoris (BF)-long head (P = 0.0001; +162 ± 97%), Semimembranosus (SM) (P = 0.0001; +304 ± 192%), and Tensor fascia latae (P = 0.0001; +586 ± 262%). The analysis of the four pedaling sectors revealed that the increased activity of hip and knee flexors mainly occurred during the top dead center and the upstroke phase. In addition, a high inter-individual variability was found in the way the participants adapted to pedaling with independent cranks. The present results showed that the enforced pull-up action required when using independent cranks was achieved by increasing the activation of hip and knee flexors. Further studies are needed to determine whether training with independent cranks has the potential to induce long-term changes in muscle coordination, and, if so, whether these changes are beneficial for cycling performance.

  15. Comparison and reproducibility of sEMG during manual muscle testing on land and in water.

    PubMed

    Silvers, W Matthew; Dolny, Dennis G

    2011-02-01

    The objectives of this study were to: (1) compare the sEMG recordings from maximal voluntary contractions (MVC), and (2) examine the reproducibility of sEMG recordings from MVCs for selected lower extremity muscles derived from manual muscle testing (MMT) on dry land, and in water prior to and following aquatic treadmill running. Twelve healthy recreational male runners participated. The selected muscles were: M. quadriceps-vastus medialis (VM) and rectus femoris (RF), M. biceps femoris (BF), M. tibialis anterior (TA) and the M. gastrocnemius caput mediale (GAS) of the right leg. The MVC testing conditions were: dry land, underwater prior to (Water 1) and following an aquatic exercise trial (Water 2). For each muscle, a one-way analysis of variance with repeated measures was used to compare MVC scores between testing conditions, and the intra-class correlation coefficient (ICC) and typical error (CV%) were calculated to determine the reproducibility and precision of MVC scores, respectively, between conditions. For all muscles, no significant differences were observed between land and water MVC scores (p=0.88-0.97), and high reliability (ICC=0.96-0.98) and precision (CV%=7.4-12.6%) were observed between MVC conditions. Under MMT conditions it appears that comparable MVC sEMG values were achieved on land and in water and the integrity of the EMG recordings were maintained during water immersion. Future studies using sEMG waterproofing procedures should conduct MVC testing in water for data normalization and perform post-exercise verification of sEMG signal integrity.

  16. Grazing-induced changes in muscle microRNA-206 and -208b expression in association with myogenic gene expression in cattle.

    PubMed

    Horikawa, Akihiko; Ogasawara, Hideki; Okada, Kaito; Kobayashi, Misato; Muroya, Susumu; Hojito, Masayuki

    2015-11-01

    To investigate the roles of microRNAs (miRNAs) in muscle type conversion, the effects of 4 months of grazing on the expression levels of miRNAs and mRNAs associated with skeletal muscle development were analyzed by quantitative RT-PCR using the Biceps femoris muscle of Japanese Shorthorn cattle. After 4 months of grazing, the expression of muscle fiber type-associated miR-208b was higher in the grazed cattle than in the housed. In concordance with the pattern in miR-208b expression, the expression of MyoD, a myogenic regulatory factor associated with the shifting of muscle property to the fast type, was lower in the grazed cattle after 4 months of grazing than in the housed cattle. In addition, the expression of MyHC-2x (a fast type) was higher in the housed cattle than in the grazed, after 4 months of grazing. During the grazing period, miR-206 expression decreased in the housed cattle, whereas expression in the grazed cattle did not change, but rather remained higher than that of the housed cattle even at 3 months after the grazing ended. These miRNAs including miR-206 persisting with muscles of grazed cattle may be associated with regulation of muscle gene expression during skeletal muscle adaptation to grazing.

  17. Quadratus femoris: An EMG investigation during walking and running.

    PubMed

    Semciw, Adam I; Freeman, Michael; Kunstler, Breanne E; Mendis, M Dilani; Pizzari, Tania

    2015-09-18

    Dysfunction of hip stabilizing muscles such as quadratus femoris (QF) is identified as a potential source of lower extremity injury during functional tasks like running. Despite these assumptions, there are currently no electromyography (EMG) data that establish the burst activity profile of QF during any functional task like walking or running. The objectives of this study were to characterize and compare the EMG activity profile of QF while walking and running (primary aim) and describe the direction specific action of QF (secondary aim). A bipolar fine-wire intramuscular electrode was inserted via ultrasound guidance into the QF of 10 healthy participants (4 females). Ensemble curves were generated from four walking and running trials, and normalized to maximum voluntary isometric contractions (MVICs). Paired t-tests compared the temporal and amplitude EMG variables. The relative activity of QF in the MVICs was calculated. The QF displayed moderate to high amplitude activity in the stance phase of walking and very high activity during stance in running. During swing, there was minimal QF activity recorded during walking and high amplitudes were present while running (run vs walk effect size=4.23, P<0.001). For the MVICs, external rotation and clam produced the greatest QF activity, with the hip in the anatomical position. This study provides an understanding of the activity demands placed on QF while walking and running. The high activity in late swing during running may signify a synergistic role with other posterior thigh muscles to control deceleration of the limb in preparation for stance.

  18. Relationship between skin temperature and muscle activation during incremental cycle exercise.

    PubMed

    Priego Quesada, Jose I; Carpes, Felipe P; Bini, Rodrigo R; Salvador Palmer, Rosario; Pérez-Soriano, Pedro; Cibrián Ortiz de Anda, Rosa M

    2015-02-01

    While different studies showed that better fitness level adds to the efficiency of the thermoregulatory system, the relationship between muscular effort and skin temperature is still unknown. Therefore, the present study assessed the relationship between neuromuscular activation and skin temperature during cycle exercise. Ten physically active participants performed an incremental workload cycling test to exhaustion while neuromuscular activations were recorded (via surface electromyography - EMG) from rectus femoris, vastus lateralis, biceps femoris and gastrocnemius medialis. Thermographic images were recorded before, immediately after and 10 min after finishing the cycling test, at four body regions of interest corresponding to the muscles where neuromuscular activations were monitored. Frequency band analysis was conducted to assess spectral properties of EMG signals in order to infer on priority in recruitment of motor units. Significant inverse relationship between changes in skin temperature and changes in overall neuromuscular activation for vastus lateralis was observed (r<-0.5 and p<0.04). Significant positive relationship was observed between skin temperature and low frequency components of neuromuscular activation from vastus lateralis (r>0.7 and p<0.01). Participants with larger overall activation and reduced low frequency component for vastus lateralis activation presented a better adaptive response of their thermoregulatory system by showing fewer changes in skin temperature after incremental cycling test.

  19. Effects of a leaf spring structured midsole on joint mechanics and lower limb muscle forces in running

    PubMed Central

    Wunsch, Tobias; Alexander, Nathalie; Kröll, Josef; Stöggl, Thomas; Schwameder, Hermann

    2017-01-01

    To enhance running performance in heel-toe running, a leaf spring structured midsole shoe (LEAF) has recently been introduced. The purpose of this study was to investigate the effect of a LEAF compared to a standard foam midsole shoe (FOAM) on joint mechanics and lower limb muscle forces in overground running. Nine male long-distance heel strike runners ran on an indoor track at 3.0 ± 0.2 m/s with LEAF and FOAM shoes. Running kinematics and kinetics were recorded during the stance phase. Absorbed and generated energy (negative and positive work) of the hip, knee and ankle joint as well as muscle forces of selected lower limb muscles were determined using a musculoskeletal model. A significant reduction in energy absorption at the hip joint as well as energy generation at the ankle joint was found for LEAF compared to FOAM. The mean lower limb muscle forces of the m. soleus, m. gastrocnemius lateralis and m. gastrocnemius medialis were significantly reduced for LEAF compared to FOAM. Furthermore, m. biceps femoris showed a trend of reduction in running with LEAF. The remaining lower limb muscles analyzed (m. gluteus maximus, m. rectus femoris, m. vastus medialis, m. vastus lateralis, m. tibialis anterior) did not reveal significant differences between the shoe conditions. The findings of this study indicate that LEAF positively influenced the energy balance in running by reducing lower limb muscle forces compared to FOAM. In this way, LEAF could contribute to an overall increased running performance in heel-toe running. PMID:28234946

  20. Effects of a leaf spring structured midsole on joint mechanics and lower limb muscle forces in running.

    PubMed

    Wunsch, Tobias; Alexander, Nathalie; Kröll, Josef; Stöggl, Thomas; Schwameder, Hermann

    2017-01-01

    To enhance running performance in heel-toe running, a leaf spring structured midsole shoe (LEAF) has recently been introduced. The purpose of this study was to investigate the effect of a LEAF compared to a standard foam midsole shoe (FOAM) on joint mechanics and lower limb muscle forces in overground running. Nine male long-distance heel strike runners ran on an indoor track at 3.0 ± 0.2 m/s with LEAF and FOAM shoes. Running kinematics and kinetics were recorded during the stance phase. Absorbed and generated energy (negative and positive work) of the hip, knee and ankle joint as well as muscle forces of selected lower limb muscles were determined using a musculoskeletal model. A significant reduction in energy absorption at the hip joint as well as energy generation at the ankle joint was found for LEAF compared to FOAM. The mean lower limb muscle forces of the m. soleus, m. gastrocnemius lateralis and m. gastrocnemius medialis were significantly reduced for LEAF compared to FOAM. Furthermore, m. biceps femoris showed a trend of reduction in running with LEAF. The remaining lower limb muscles analyzed (m. gluteus maximus, m. rectus femoris, m. vastus medialis, m. vastus lateralis, m. tibialis anterior) did not reveal significant differences between the shoe conditions. The findings of this study indicate that LEAF positively influenced the energy balance in running by reducing lower limb muscle forces compared to FOAM. In this way, LEAF could contribute to an overall increased running performance in heel-toe running.

  1. Open Subpectoral Tenodesis of the Proximal Biceps.

    PubMed

    Voss, Andreas; Cerciello, Simone; Yang, Justin; Beitzel, Knut; Cote, Mark P; Mazzocca, Augustus D

    2016-01-01

    This article summarizes both the various techniques for an open subpectoral biceps tenodesis as well as the biomechanics associated with these procedures. It provides information regarding the indications and contraindications to support the surgeon's decision. Furthermore, a postoperative protocol as well as an outcome overview is presented to address postoperative care. A short summary of the recent literature regarding potential complications is included to provide further insight on this technique. The open subpectoral tenodesis of the long head of the biceps is a safe and reproducible technique with a low complication rate for patients with pathologies of the proximal biceps.

  2. Effect of ski simulator training on kinematic and muscle activation of the lower extremities.

    PubMed

    Moon, Jeheon; Koo, Dohoon; Kim, Kitae; Shin, Insik; Kim, Hyeyoung; Kim, Jinhae

    2015-08-01

    [Purpose] This study aimed to verify the effectiveness of an augmented reality-based ski simulator through analyzing the changes in movement patterns as well as the engagement of major muscles of the lower body. [Subjects] Seven subjects participated in the study. All were national team-level athletes studying at "K" Sports University in Korea who exhibited comparable performance levels and had no record of injuries in the preceding 6 months (Age 23.4 ± 3.8 years; Height 172.6 ± 12.1 cm; Weight 72.3 ± 16.2 kg; Experience 12.3 ± 4.8 years). [Methods] A reality-based ski simulator developed by a Korean manufacturer was used for the study. Three digital video cameras and a wireless electromyography system were used to perform 3-dimensional motion analysis and measure muscle activation level. [Results] Left hip angulation was found to increase as the frequency of the turns increased. Electromyography data revealed that the activation level of the quadriceps group's extension muscles and the biceps femoris group's flexing muscles had a crossing pattern. [Conclusion] Sustained training using an augmented reality-based ski simulator resulted in movements that extended the lower body joints, which is thought to contribute to increasing muscle fatigue.

  3. Effect of ski simulator training on kinematic and muscle activation of the lower extremities

    PubMed Central

    Moon, Jeheon; Koo, Dohoon; Kim, Kitae; Shin, Insik; Kim, Hyeyoung; Kim, Jinhae

    2015-01-01

    [Purpose] This study aimed to verify the effectiveness of an augmented reality-based ski simulator through analyzing the changes in movement patterns as well as the engagement of major muscles of the lower body. [Subjects] Seven subjects participated in the study. All were national team-level athletes studying at “K” Sports University in Korea who exhibited comparable performance levels and had no record of injuries in the preceding 6 months (Age 23.4 ± 3.8 years; Height 172.6 ± 12.1 cm; Weight 72.3 ± 16.2 kg; Experience 12.3 ± 4.8 years). [Methods] A reality-based ski simulator developed by a Korean manufacturer was used for the study. Three digital video cameras and a wireless electromyography system were used to perform 3-dimensional motion analysis and measure muscle activation level. [Results] Left hip angulation was found to increase as the frequency of the turns increased. Electromyography data revealed that the activation level of the quadriceps group’s extension muscles and the biceps femoris group’s flexing muscles had a crossing pattern. [Conclusion] Sustained training using an augmented reality-based ski simulator resulted in movements that extended the lower body joints, which is thought to contribute to increasing muscle fatigue. PMID:26357449

  4. Assessment of Skeletal Muscle Perfusion using Contrast-Enhanced Ultrasonography: Technical Note

    PubMed Central

    Qureshi, Adnan I.; Saleem, Muhammad A.; Aytac, Emrah; Wallery, Shawn S.

    2017-01-01

    Background Intravenous contrast-enhanced ultrasonography is a recently developed technique for assessment of tissue perfusion, but has not been used for assessment of skeletal muscle perfusion. Methods We studied a 42-year-old woman in whom myonecrosis was suspected due to systemic vasculitis and ischemia. The biceps brachii (right) and quadriceps femoris (vastus medialis) on right-hand side and subsequently left-hand side were imaged. Intravenous bolus of activated perflutren lipid microspheres was injected and B-Flow color mode (brown color) was used within a selected region of interest to image the passage of contrast through muscle parenchyma throughout three cardiac cycles. Results Visual interpretation of muscle perfusion was performed based on the maximal intensity of contrast in the muscle, and the speed of contrast replenishment. No deficits were noted in the perfusion pattern. The arterial phase demonstrated stellate vascularity, centrifugal filling, and homogeneous hypervascularity at peak enhancement. Conclusions The bolus of contrast resulted in good signal persistence and satisfactory imaging for multiple muscle groups. PMID:28243350

  5. Effect of antagonist muscle fatigue on knee extension torque.

    PubMed

    Beltman, J G M; Sargeant, A J; Ball, D; Maganaris, C N; de Haan, A

    2003-09-01

    The effect of hamstring fatigue on knee extension torque was examined at different knee angles for seven male subjects. Before and after a dynamic flexion fatigue protocol (180 degrees s(-1), until dynamic torque had declined by 50%), maximal voluntary contraction extension torque was measured at four knee flexion angles (90 degrees, 70 degrees, 50 degrees and 30 degrees ). Maximal torque generating capacity and voluntary activation of the quadriceps muscle were determined using electrical stimulation. Average rectified EMG of the biceps femoris was determined. Mean dynamic flexion torque declined by 48+/-11%. Extensor maximal voluntary contraction torque, maximal torque generating capacity, voluntary activation and average rectified EMG at the four knee angles were unaffected by the hamstring fatigue protocol. Only at 50 degrees knee angle was voluntary activation significantly lower (15.7%) after fatigue ( P<0.05). In addition, average rectified EMG before fatigue was not significantly influenced by knee angle. It was concluded that a fatigued hamstring muscle did not increase the maximal voluntary contraction extension torque and knee angle did not change coactivation. Three possible mechanisms may explain the results: a potential difference in recruited fibre populations in antagonist activity compared with the fibres which were fatigued in the protocol, a smaller loss in isometric torque generating capacity of the hamstring muscle than was expected from the dynamic measurements and/or a reduction in voluntary activation.

  6. Glenoid labrum tears related to the long head of the biceps.

    PubMed

    Andrews, J R; Carson, W G; McLeod, W D

    1985-01-01

    Tears of the glenoid labrum were observed in 73 baseball pitchers and other throwing athletes who underwent arthroscopic examination of the dominant shoulder. Most of the tears were located over the anterosuperior portion of the glenoid labrum near the origin of the tendon of the long head of the biceps muscle into the glenoid. At arthroscopy, the tendon of the long head of the biceps appeared to originate through and be continuous with the superior portion of the glenoid labrum. In many cases it appeared to have pulled the anterosuperior portion of the labrum off the glenoid. This observation was verified at arthroscopy by viewing the origin of the biceps tendon into the glenoid labrum as the muscle was electrically stimulated. With stimulation of the muscle, the tendinous portion became quite taut, particularly near its attachment to the glenoid labrum, and actually lifted the labrum off the glenoid. Three-dimensional high-speed cinematography with computer analysis revealed that the moment acting about the elbow joint to extend the joint through an arc of about 50 degrees was in excess of 600 inch-pounds. The extremely high velocity of elbow extension which is generated must be decelerated through the final 30 degrees of elbow extension. Of the muscles of the arm that provide the large deceleration forces in the follow-through phase of throwing, only the biceps brachii traverses both the elbow joint and the shoulder joint. Additional forces are generated in the biceps tendon in its function as a "shunt" muscle to stabilize the glenohumeral joint during the throwing act.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Increased insulin-stimulated glucose uptake in both leg and arm muscles after sprint interval and moderate intensity training in subjects with Type 2 Diabetes or Prediabetes.

    PubMed

    Sjöros, Tanja J; Heiskanen, Marja A; Motiani, Kumail K; Löyttyniemi, Eliisa; Eskelinen, Jari-Joonas; Virtanen, Kirsi A; Savisto, Nina J; Solin, Olof; Hannukainen, Jarna C; Kalliokoski, Kari K

    2017-03-13

    We investigated the effects of sprint interval (SIT) and moderate intensity continuous training (MICT) on glucose uptake (GU) during hyperinsulinemic euglycemic clamp and fatty acid uptake (FAU) at fasting state in thigh and arm muscles in subjects with type 2 diabetes (T2D) or prediabetes. Twenty-six patients (age 49, SD 4; 10 women) were randomly assigned into two groups: SIT (n=13), and MICT (n=13). The exercise in the SIT group consisted of 4-6 x 30 s of all-out cycling with 4 min recovery and in the MICT group 40-60 min cycling at 60% of VO2peak . Both groups completed six training sessions within two weeks. GU and FAU were measured before and after the intervention with positron emission tomography in thigh (quadriceps femoris, QF; and hamstrings) and upper arm (biceps and triceps brachii) muscles. Whole-body insulin-stimulated GU increased significantly by 25% in both groups and this was accompanied with significantly increased insulin-stimulated GU in all thigh and upper arm muscles and significantly increased FAU in QF. Within QF, insulin-stimulated GU improved more by SIT than MICT in rectus femoris (p=0.01), but not differently between the training modes in the other QF muscles. In individuals with T2D or prediabetes, both SIT and MICT training rapidly improve insulin-stimulated GU in whole body and in the thigh and arm muscles as well as FAU in the main working muscle QF. These findings highlight the underused potential of exercise in rapidly restoring the impaired skeletal muscle metabolism in subjects with impaired glucose metabolism. This article is protected by copyright. All rights reserved.

  8. Impact of season on the fatty acid profiles of male and female blesbok (Damaliscus pygargus phillipsi) muscles.

    PubMed

    Neethling, J; Britz, T J; Hoffman, L C

    2014-12-01

    This study quantified the impact of season on fatty acid profiles of male and female blesbok muscles (longissimus thoracis et lumborum, biceps femoris, semimembranosus, semitendinosus, infraspinatus, and supraspinatus). Eight mature blesbok were harvested per season (winter and spring). Gender and muscle type influenced (p<0.05) the fatty acid profiles of blesbok muscles, while season only influenced the C18:3ω3 (α-linolenic acid, ALA) percentages and therefore the total omega-3 poly-unsaturated fatty acids (total ω3 PUFA). Female muscles had higher C16:0 (palmitic acid) (21.01%±0.256 vs. 19.05%±0.296) and total MUFA percentages, while male muscles had higher (p<0.05) C18:2ω6c, C20:5ω3, total ω3 PUFA (11.08%±0.382 vs. 8.50%±0.367), and total PUFA (43.03%±0.904 vs. 29.59%±1.164) percentages, contributing to higher poly-unsaturated to saturated fatty acid ratios (PUFA:SFA ratios). Differences in fatty acid profiles were attributed more to gender and anatomical location of muscles, than seasonal differences in diets.

  9. Focusing on Increasing Velocity during Heavy Resistance Knee Flexion Exercise Boosts Hamstring Muscle Activity in Chronic Stroke Patients

    PubMed Central

    Jakobsen, Markus D.

    2016-01-01

    Background. Muscle strength is markedly reduced in stroke patients, which has negative implications for functional capacity and work ability. Different types of feedback during strength training exercises may alter neuromuscular activity and functional gains. Objective. To compare levels of muscle activity during conditions of blindfolding and intended high contraction speed with a normal condition of high-intensity knee flexions. Methods. Eighteen patients performed unilateral machine knee flexions with a 10-repetition maximum load. Surface electromyography (EMG) was recorded from the quadrics and hamstring muscles and normalized to maximal EMG (nEMG) of the nonparetic limb. Results. For the paretic leg, the speed condition showed higher values of muscle activity compared with the normal and blindfolded conditions for both biceps femoris and semitendinosus. Likewise, the speed condition showed higher co-contraction values compared with the normal and blindfolded conditions for the vastus lateralis. No differences were observed between exercise conditions for the nonparetic leg. Conclusion. Chronic stroke patients are capable of performing heavy resistance training with intended high speed of contraction. Focusing on speed during the concentric phase elicited higher levels of muscle activity of the hamstrings compared to normal and blindfolded conditions, which may have implications for regaining fast muscle strength in stroke survivors. PMID:27525118

  10. Lower Extremity Muscle Activation and Kinematics of Catchers When Throwing Using Various Squatting and Throwing Postures

    PubMed Central

    Peng, Yi-Chien; Lo, Kuo-Cheng; Wang, Lin-Hwa

    2015-01-01

    This study investigated the differences in joint motions and muscle activities of the lower extremities involved in various squatting postures. The motion capture system with thirty-one reflective markers attached on participants was used for motion data collection. The electromyography system was applied over the quadriceps, biceps femoris, tibialis anterior, and gastrocnemius muscles of the pivot and stride leg. The joint extension and flexion in wide squatting are greater than in general squatting (p = 0.005). Knee joint extension and flexion in general squatting are significantly greater than in wide squatting (p = 0.001). The adduction and abduction of the hip joint in stride passing are significantly greater than in step squatting (p = 0.000). Furthermore, the adduction and abduction of the knee joint in stride passing are also significantly greater than in step squatting (p = 0.000). When stride passing is performed, the muscle activation of the hamstring of the pivot foot in general squatting is significantly greater than in wide squatting (p < 0.05), and this difference continues to the stride period. Most catchers use a general or wide squatting width, exclusive of a narrow one. Therefore, the training design for strengthening the lower extremity muscles should consider the appropriateness of the common squat width to enhance squat-up performance. For lower limb muscle activation, wide squatting requires more active gastrocnemius and tibialis anterior muscles. Baseball players should extend the knee angle of the pivot foot before catching the ball. Key points Common squatting width can enhance squat-up performance through strengthening lower body muscle. Wide squatting width might improve lower body muscle activation, leading to more effective communication between the brain and the muscle group. The benefit might be improved coordination of lower body muscle. Common and wide squatting width might be cycled through training to enhance the strengthen and

  11. Two-stage muscle activity responses in decisions about leg movement adjustments during trip recovery

    PubMed Central

    Potocanac, Zrinka; Pijnappels, Mirjam; Verschueren, Sabine; van Dieën, Jaap

    2015-01-01

    Studies on neural decision making mostly investigated fast corrective adjustments of arm movements. However, fast leg movement corrections deserve attention as well, since they are often required to avoid falling after balance perturbations. The present study aimed at elucidating the mechanisms behind fast corrections of tripping responses by analyzing the concomitant leg muscle activity changes. This was investigated in seven young adults who were tripped in between normal walking trials and took a recovery step by elevating the tripped leg over the obstacle. In some trials, a forbidden landing zone (FZ) was presented behind the obstacle, at the subjects' preferred foot landing position, forcing a step correction. Muscle activity of the tripped leg gastrocnemius medialis (iGM), tibialis anterior (iTA), rectus femoris (iRF), and biceps femoris (iBF) muscles was compared between normal trips presented before any FZ appearance, trips with a FZ, and normal trips presented in between trips with a FZ (“catch” trials). When faced with a real or expected (catch trials) FZ, subjects shortened their recovery steps. The underlying changes in muscle activity consisted of two stages. The first stage involved reduced iGM activity, occurring at a latency shorter than voluntary reaction, followed by reduced iTA and increased iBF and iGM activities occurring at longer latencies. The fast response was not related to step shortening, but longer latency responses clearly were functional. We suggest that the initial response possibly acts as a “pause,” allowing the nervous system to integrate the necessary information and prepare the subsequent, functional movement adjustment. PMID:26561597

  12. [Evaluation of surgical repair of distal biceps tendon ruptures].

    PubMed

    Behounek, J; Hrubina, M; Skoták, M; Krumpl, O; Zahálka, M; Dvorák, J; Fucík, M

    2009-02-01

    PURPOSE OF THE STUDY To present the results of surgical repair of ruptures of the distal tendon of the biceps brachii muscle and thus show the adequacy of this treatment. MATERIAL Between 1987 and 2006, 19 patients had surgery for distal biceps tendon rupture. Only one side was affected in each patient. All patients were men between 28 and 69 years (average age, 47.5 years) at the time of injury (surgery). When the patients were evaluated at the end of 2007, 18 patients were included, because one died a year after surgery. METHODS The surgical repair always included a single-incision anatomical reattachment into the radial tuberosity. In 11 patients, a modified Mac Reynolds method with screw and washer fixation was used; in seven patients the insertion was fixed with Mitek anchors and, in one, it was sutured to the adjacent soft tissues. The average follow-up was 7 years (range, 1 to 20.5 years). The patients were evaluated for the cause of injury, their physical activity, age, dominance of the injured arm, surgical procedure and complications. RESULTS In 18 patients surgical repair was done early and, in one, at 16 days after injury. In all of them the tendon was detached from its site of insertion, but never torn. The intra-operative complications included, in one patient, bleeding owing to iatrogenic damage to a branch of the brachial artery, and difficult separation of the tendon due to its previous healed injury in another patient. Early post-operative complications included superficial skin necrosis in one patient and transient neurological deficit of the dorsal brand of the radial nerve and of the lateral cutaneous nerve of the forearm in two and one patient, respectively. The late complications were heterotropic ossification in three patients and screw migration in the one treated by the Mac Reynolds method. Excellent results were recorded in 11 patients (61 %), and good outcomes with a slight restriction of motion or muscle strength not limiting the

  13. Squeezing the muscle: compression clothing and muscle metabolism during recovery from high intensity exercise.

    PubMed

    Sperlich, Billy; Born, Dennis-Peter; Kaskinoro, Kimmo; Kalliokoski, Kari K; Laaksonen, Marko S

    2013-01-01

    The purpose of this experiment was to investigate skeletal muscle blood flow and glucose uptake in m. biceps (BF) and m. quadriceps femoris (QF) 1) during recovery from high intensity cycle exercise, and 2) while wearing a compression short applying ~37 mmHg to the thigh muscles. Blood flow and glucose uptake were measured in the compressed and non-compressed leg of 6 healthy men by using positron emission tomography. At baseline blood flow in QF (P = 0.79) and BF (P = 0.90) did not differ between the compressed and the non-compressed leg. During recovery muscle blood flow was higher compared to baseline in both compressed (P<0.01) and non-compressed QF (P<0.001) but not in compressed (P = 0.41) and non-compressed BF (P = 0.05; effect size = 2.74). During recovery blood flow was lower in compressed QF (P<0.01) but not in BF (P = 0.26) compared to the non-compressed muscles. During baseline and recovery no differences in blood flow were detected between the superficial and deep parts of QF in both, compressed (baseline P = 0.79; recovery P = 0.68) and non-compressed leg (baseline P = 0.64; recovery P = 0.06). During recovery glucose uptake was higher in QF compared to BF in both conditions (P<0.01) with no difference between the compressed and non-compressed thigh. Glucose uptake was higher in the deep compared to the superficial parts of QF (compression leg P = 0.02). These results demonstrate that wearing compression shorts with ~37 mmHg of external pressure reduces blood flow both in the deep and superficial regions of muscle tissue during recovery from high intensity exercise but does not affect glucose uptake in BF and QF.

  14. Influence of type of muscles on nutritional value of foal meat.

    PubMed

    Lorenzo, José M; Pateiro, Mirian

    2013-03-01

    The effect of type of muscle on nutritional characteristic (fatty acid profile, amino acid content, cholesterol and major and minor mineral) of foal meat was investigated. Six muscles: longissimus dorsi (LD), semimembranosus (SM), semitendinosus (ST), biceps femoris (BF), triceps brachii (TB) and psoas major & minor (PM) from twelve foals slaughtered at 15 months from an extensive production system in freedom regimen were extracted for this study. Horse meat is characterized by low fat, low cholesterol content, rich in iron and in vitamin B. Statistical analysis showed that the cholesterol content did not show significant differences (P>0.05) among muscle with mean value range between 0.62 and 0.57 mg/100g. Most fatty acid presented significant differences (P<0.05) with respect to the type of muscle. The obtained results showed that except for the polyunsaturated linoleic acid, the highest contents of fatty acids were found in the hindquarter muscles. Regarding amino acid profile, significant differences (P<0.05) were observed among muscles and our results indicated that, 100g of foal meat covered from 80.6 to 86.7% for the daily requirement for an adult man weighing 70 kg for essential amino acids for ST and LD muscles, respectively. Statistical analysis showed significant differences (P=0.050) for the EAA (essential amino acids) index, which was highest for TB muscle, followed by BF and SM muscles, while the lowest values were reported by ST muscle. Finally, foal meat seems to be a very good nutritional source of major and minor minerals. The higher nutritional value of foal meat will be of great importance in the promotion of this meat.

  15. Antagonist muscle co-activation of limbs in human infant crawling: A pilot study.

    PubMed

    Xiong, Qi L; Wu, Xiao Y; Xiao, Nong; Zeng, Si Y; Wan, Xiao P; Zheng, Xiao L; Hou, Wen S

    2015-01-01

    Muscle Co-activation (MCo) is the simultaneous muscular activation of agonist and antagonist muscle groups, which provides adequate joint stability, movement accuracy during movement. Infant crawling is an important stage of motor function development that manifests non-synchronization growth and development of upper and lower limbs due to the well-known gross motor development principle of head to toe. However, the effect of MCo level for agonist and antagonist muscle groups on motor function development of limbs has not been previously reported. In this paper, sEMG signals were collected from triceps brachii (TB) and biceps brachii (BB), quadriceps femoris (QF) and hamstrings (HS) of limbs when fourteen infants were crawling at their self-selected speed. Antagonist muscle co-activation was evaluated by measuring two common indexes (co-activation index and Pearson's correlation coefficient).A significant difference was observed between upper limbs and lower limbs, but the relationship between MCo and speed of crawling was poor. This study is an opening for further investigation including a longitudinal study and compare against infant with CNS disorders.

  16. Individual Muscle use in Hamstring Exercises by Soccer Players Assessed using Functional MRI.

    PubMed

    Fernandez-Gonzalo, R; Tesch, P A; Linnehan, R M; Kreider, R B; Di Salvo, V; Suarez-Arrones, L; Alomar, X; Mendez-Villanueva, A; Rodas, G

    2016-06-01

    This study used functional magnetic resonance imaging (fMRI) to compare individual muscle use in exercises aimed at preventing hamstring injuries. Thirty-six professional soccer players were randomized into 4 groups, each performing either Nordic hamstring, flywheel leg curl, Russian belt or conic-pulley exercise. MRIs were performed before and immediately after a bout of 4 sets of 8 repetitions. Pre-post exercise differences in contrast shift (T2) were analyzed for the long (BFLh) and short head (BFSh) of biceps femoris, semitendinosus (ST), semimembranosus (SM) and gracilis (GR) muscles. Flywheel leg curl increased (P<0.001) T2 of GR (95%), ST (65%), BFSh (51%) and BFLh (14%). After the Nordic hamstring, GR (39%), ST (16%) and BFSh (14%) showed increased T2 (P<0.001). Russian belt and conic-pulley exercise produced subtle (P<0.02) T2 increases of ST (9 and 6%, respectively) and BFLh (7 and 6%, respectively). Russian belt increased T2 of SM (7%). Among exercises examined, flywheel leg curl showed the most substantial hamstring and GR muscle use. However, no single exercise executed was able to increase T2 of all hamstring and synergist muscles analyzed. It is therefore suggested that multiple exercises must be carried out to bring in, and fully activate all knee flexors and hip extensors.

  17. Bedside Ultrasound Measurement of Rectus Femoris: A Tutorial for the Nutrition Support Clinician

    PubMed Central

    Monares Zepeda, Enrique; Lescas Méndez, Octavio Augusto

    2017-01-01

    Intensive care unit acquired weakness is a long-term consequence after critical illness; it has been related to muscle atrophy and can be considered as one of the main nutritional support challenges at the intensive care unit. Measuring muscle mass by image techniques has become a new area of research for the nutritional support field, extending our knowledge about muscle wasting and the impact of nutritional approaches in the critical care setting, although currently there is no universally accepted technique to perform muscle measurements by ultrasound. Because of this, we present this tutorial for nutrition support clinicians, in order to understand and perform muscle measurements by this reliable, accessible, low-cost, and easy-to-use technique. Reviewing issues such as quadriceps muscle anatomy, correct technique (do's and don'ts), identification of structures, and measurement of the rectus femoris and vastus intermedius muscles helps to acquire the basic concepts of this technique and encouraging more research in this field. PMID:28386479

  18. How Accurate Are We in Detecting Biceps Tendinopathy?

    PubMed

    Carr, Ryan M; Shishani, Yousef; Gobezie, Reuben

    2016-01-01

    Biceps tendon pain is frequently called biceps "tendinitis," or inflammation of the biceps tendon. Histologic analysis of biceps tendon biopsies demonstrates changes in tenocyte size, ground substance, collagen organization, and vascularity observed with many different tendinopathies. There are distinct symptoms of biceps tendinopathy and a few provocative maneuvers can help make the diagnosis. Imaging studies (eg, MRI) can show changes in signal sequence or tears. However, MRI has a low sensitivity and frequently results in missed or misdiagnosed biceps pathology. Clinical decision making is best guided by a strong clinical suspicion based on patient history, physical examination, and MRI.

  19. Proximal Rectus Femoris Avulsion: Ultrasonic Diagnosis and Nonoperative Management

    PubMed Central

    Esser, Stephan; Jantz, David; Hurdle, Mark F.; Taylor, Walter

    2015-01-01

    Objective To present a case of ultrasonic diagnosis and nonoperative management of a complete proximal rectus femoris avulsion in a National Collegiate Athletic Association Division 1 soccer goalkeeper. Background While delivering a goal kick, a previously uninjured 24-year-old collegiate soccer goalkeeper had the sudden onset of right anterior thigh pain. He underwent rehabilitation with rapid resolution of his presenting pain but frequent intermittent recurrence of anterior thigh pain. After he was provided a definitive diagnosis with musculoskeletal ultrasound, he underwent an extended period of rehabilitation and eventually experienced complete recovery without recurrence. Differential Diagnosis Rectus femoris avulsion, rectus femoris strain or partial tear, inguinal hernia, or acetabular labral tear. Treatment Operative and nonoperative options were discussed. In view of the player's recovery, nonoperative options were pursued with a good result. Uniqueness Complete proximal rectus femoris avulsions are rare. Our case contributes to the debate on whether elite-level kicking and running athletes can return to full on-field performance without surgery. Conclusions Complete proximal rectus femoris avulsions can be treated effectively using nonoperative measures with good preservation of function even in the elite-level athlete. In addition, musculoskeletal ultrasound is an excellent tool for on-site evaluation and may help guide prognosis and management. PMID:25978099

  20. Muscle activity during the active straight leg raise (ASLR), and the effects of a pelvic belt on the ASLR and on treadmill walking.

    PubMed

    Hu, Hai; Meijer, Onno G; van Dieën, Jaap H; Hodges, Paul W; Bruijn, Sjoerd M; Strijers, Rob L; Nanayakkara, Prabath W; van Royen, Barend J; Wu, Wenhua; Xia, Chun

    2010-02-10

    Women with pregnancy-related pelvic girdle pain (PPP), or athletes with groin pain, may have trouble with the active straight leg raise (ASLR), for which a pelvic belt can be beneficial. How the problems emerge, or how the belt works, remains insufficiently understood. We assessed muscle activity during ASLR, and how it changes with a pelvic belt. Healthy nulligravidae (N=17) performed the ASLR, and walked on a treadmill at increasing speeds, without and with a belt. Fine-wire electromyography (EMG) was used to record activity of the mm. psoas, iliacus and transversus abdominis, while other hip and trunk muscles were recorded with surface EMG. In ASLR, all muscles were active. In both tasks, transverse and oblique abdominal muscles were less active with the belt. In ASLR, there was more activity of the contralateral m. biceps femoris, and in treadmill walking of the m. gluteus maximus in conditions with a belt. For our interpretation, we take our starting point in the fact that hip flexors exert a forward rotating torque on the ilium. Apparently, the abdominal wall was active to prevent such forward rotation. If transverse and oblique abdominal muscles press the ilia against the sacrum (Snijders' "force closure"), the pelvis may move as one unit in the sagittal plane, and also contralateral hip extensor activity will stabilize the ipsilateral ilium. The fact that transverse and oblique abdominal muscles were less active in conditions with a pelvic belt suggests that the belt provides such "force closure", thus confirming Snijders' theory.

  1. Composite inflation confronts BICEP2 and PLANCK

    SciTech Connect

    Karwan, Khamphee; Channuie, Phongpichit E-mail: phongpichit.ch@wu.ac.th

    2014-06-01

    We examine observational constraints on single-field inflation in which the inflaton is a composite field stemming from a four-dimensional strongly interacting field theory. We confront the predictions with the Planck and very recent BICEP2 data. In the large non-minimal coupling regions, we discover for the minimal composite inflationary model that the predictions lie well inside the joint 68% CL for the Planck data, but is in tension with the recent BICEP2 observations. In the case of the glueball inflationary model, the predictions satisfy the Planck results. However, this model can produce a large tensor-to-scalar ratio consistent with the recent BICEP2 observations if the number of e-foldings is slightly smaller than the range commonly used. For a super Yang-Mills paradigm, we discover that the predictions satisfy the Planck data, and surprisingly a large tensor-to-scalar ratio consistent with the BICEP2 results can also be produced for an acceptable range of the number of e-foldings and of the confining scale. In the small non-minimal coupling regions, all of the models can satisfy the BICEP2 results. However, the predictions of the glueball and superglueball inflationary models cannot satisfy the observational bound on the amplitude of the curvature perturbation launched by Planck, and the techni-inflaton self-coupling in the minimal composite inflationary model is constrained to be extremely small.

  2. Optimal Burst Duration During a Facilitated Quadriceps Femoris Contraction

    PubMed Central

    McLoda, Todd A.; Carmack, Jennifer A.

    2000-01-01

    Objective: To determine the most efficient burst duty cycle for eliciting an involuntary quadriceps femoris contraction in healthy subjects. This information will allow clinicians to make an informed decision about the optimal burst duty cycle based upon a specific treatment goal. The logical goal for such a treatment choice is to enhance motor unit recruitment in an effort to maintain postoperative or postinjury strength, when voluntary contractions may be less effective. Design and Setting: Single-group and 5-measures design. All tests were performed in a university laboratory. Subjects: Forty-eight healthy subjects (27 men and 21 women; mean age, 26.4 ± 8.5 years) performed a maximal voluntary isometric contraction (MVIC) on an isokinetic device and received neuromuscular electrical stimulation (NMES) at 5 different burst duty cycles. Measurements: Subjects first performed an MVIC for knee extension on an isokinetic dynamometer at 60° of knee flexion. NMES surface electrodes were applied to the quadriceps muscle of each subject's dominant leg. The values for the NMES were 2500-Hz carrier frequency, 50-bursts-per-second treatment frequency, amplitude increased to maximum tolerance, and burst duty cycle set to each of the 5 comparison values. The peak isometric force generated by each of the 5 nonvolitional contractions was recorded, along with the maximal charge per burst tolerated by each subject. Force generated was described as percentage of MVIC. Efficiency was the amount of force per burst charge. Results: The mean MVIC achieved by the subjects was 553.8 newtons (N). The average force per burst charge generated at 10% burst duty cycle was 132.9 N; at 30%, 104.2 N; at 50%, 93.1 N; at 70%, 52.9 N; and at 90%, 41.3 N. The average efficiency (force per millicoulombs [mC]) at 10% burst duty cycle was the highest at 6.49 N/mC and at 90% was the lowest at 1.05 N/mC. Conclusions: A burst duty cycle of 10% was the most efficient ratio of burst duration to

  3. Leg and trunk muscle coordination and postural sway during increasingly difficult standing balance tasks in young and older adults.

    PubMed

    Donath, Lars; Kurz, Eduard; Roth, Ralf; Zahner, Lukas; Faude, Oliver

    2016-09-01

    Ageing impairs body balance and increases older adults' fall risk. Balance training can improve intrinsic fall risk factors. However, age comparisons of muscle activity responses during balance tasks are lacking. This study investigated relative muscle activity, muscle coordination and postural sway during various recommended static balance training tasks. Muscle activity (%MVC), amplitude ratios (AR) and co-activity (CAI) were determined during standing tasks for 30s (1: double limb stance on a foam surface, eyes open; 2: double limb stance on firm ground, eyes closed; 3: double limb stance, feet in step position on a foam surface, eyes open; 4: double limb stance, feet in step position on firm ground, eyes closed; 5: single limb stance on firm ground, eyes open) in 20 healthy young adults (24±2 y) and 20 older adults (73±6 y). Surface electromyography (SEMG) was applied (SENIAM guidelines) to ankle (tibialis anterior, soleus, medial gastrocnemius, peroneus longus) and thigh (vastus lateralis, vastus medialis, biceps femoris, semitendinosus) muscles (non-dominant leg). Electrodes over trunk (multifidus and internal oblique) muscles were applied bilaterally. Two- to six-fold higher levels of relative muscle activity were found in older adults for ankle (0.0002muscles. Co-activation was elevated in young adults for the trunk (0.001muscle coordination patterns during all stance conditions at the ankle (0.06<ηp(2)<0.28) and the trunk (0.14<ηp(2)<0.23). Older adults had higher electrophysiological costs for all stance conditions. Muscle coordination showed inverse activity patterns at the ankle and trunk. Optimal balance and strength training programs should take into account age-specific alterations in muscle activity.

  4. Effects of a 10-week resistance exercise program on soccer kick biomechanics and muscle strength.

    PubMed

    Manolopoulos, Evaggelos; Katis, Athanasios; Manolopoulos, Konstantinos; Kalapotharakos, Vasileios; Kellis, Eleftherios

    2013-12-01

    The purpose of the study was to examine the effects of a resistance exercise program on soccer kick biomechanics. Twenty male amateur soccer players were divided in the experimental group (EG) and the control group (CG), each consisting of 10 players. The EG followed a 10-week resistance exercise program mainly for the lower limb muscles. Maximal instep kick kinematics, electromyography, and ground reaction forces (GRFs) as well as maximum isometric leg strength were recorded before and after training. A 2-way analysis of variance showed significantly higher ball speed values only for the EG (26.14 ± 1.17 m·s vs. 27.59 ± 1.49 m·s before and after training, respectively), whereas no significant differences were observed for the CG. The EG showed a decline in joint angular velocities and an increase in biceps femoris electromyography of the swinging leg during the backswing phase followed by a significant increase in segmental and joint velocities and muscle activation of the same leg during the forward swing phase (p < 0.05). The EG also showed significantly higher vertical GRFs and rectus femoris and gastrocnemius activation of the support leg (p < 0.05). Similarly, maximum and explosive isometric force significantly increased after training only for the EG (p < 0.05). These results suggest that increases in soccer kicking performance after a 10-week resistance training program were accompanied by increases in maximum strength and an altered soccer kick movement pattern, characterized by a more explosive backward-forward swinging movement and higher muscle activation during the final kicking phase.

  5. Chemical composition and amino acid profiles of goose muscles from native Polish breeds.

    PubMed

    Okruszek, A; Woloszyn, J; Haraf, G; Orkusz, A; Werenska, M

    2013-04-01

    The aim of the study was to compare the chemical and amino acid composition of breast (pectoralis major) and thigh (biceps femoris) muscles in 17-wk-old geese from 2 Polish conservative flocks: Rypińska (Ry, n = 20) and Garbonosa (Ga, n = 20). The geese were fed ad libitum during the experimental period on the same complete feed. Genotypes affected the moisture and fat content of breast and thigh meat. The Ga geese were characterized by higher moisture as well as lower fat lipid content compared with the Ry breast and thigh muscles. The amino acid proportions of meat proteins depended on the goose flock and type of muscles, where significant differences were found. The proteins of Ga breast muscles contained more glutamic acid, glycine, lysine, tryptophan, histidine, and methionine, and less aspartic acid, proline, serine, leucine, valine, phenyloalanine, tyrosine, and threonine than the Ry geese (P ≤ 0.05). The proteins of Ry thigh muscles were characterized by higher content of proline, serine, and essential amino acids (without lysine and methionine) and lower glutamic and asparagine acid, alanine, and glycine compared with the Ga flock. According to the Food and Agriculture Organization of the United Nations/World Health Organization (1991) standard, tryptophan was the amino acid limiting the nutritional value of meat proteins of Ry breast muscles (amino acid score for tryptophan = 90%). Except for tryptophan, the meat proteins of the investigated raw materials contained more essential amino acids than the standard. The total content of essential amino acids for all investigated muscles was also higher (52.51 to 55.54%) than the standard (33.90%). It is evident that muscle protein from both flocks of geese have been characterized by high nutritional value. The values of the essential amino acid index of breast muscle proteins were similar in both flocks.

  6. Raman spectroscopic study of acute oxidative stress induced changes in mice skeletal muscles

    NASA Astrophysics Data System (ADS)

    Sriramoju, Vidyasagar; Alimova, Alexandra; Chakraverty, Rahul; Katz, A.; Gayen, S. K.; Larsson, L.; Savage, H. E.; Alfano, R. R.

    2008-02-01

    The oxidative stress due to free radicals is implicated in the pathogenesis of tissue damage in diseases such as muscular dystrophy, Alzheimer dementia, diabetes mellitus, and mitochrondrial myopathies. In this study, the acute oxidative stress induced changes in nicotinamide adenine dinucleotides in mouse skeletal muscles are studied in vitro using Raman spectroscopy. Mammalian skeletal muscles are rich in nicotinamide adenine dinucleotides in both reduced (NADH) and oxidized (NAD) states, as they are sites of aerobic and anaerobic respiration. The relative levels of NAD and NADH are altered in certain physiological and pathological conditions of skeletal muscles. In this study, near infrared Raman spectroscopy is used to identify the molecular fingerprints of NAD and NADH in five-week-old mice biceps femoris muscles. A Raman vibrational mode of NADH is identified in fresh skeletal muscle samples suspended in buffered normal saline. In the same samples, when treated with 1% H IIO II for 5 minutes and 15 minutes, the Raman spectrum shows molecular fingerprints specific to NAD and the disappearance of NADH vibrational bands. The NAD bands after 15 minutes were more intense than after 5 minutes. Since NADH fluoresces and NAD does not, fluorescence spectroscopy is used to confirm the results of the Raman measurements. Fluorescence spectra exhibit an emission peak at 460 nm, corresponding to NADH emission wavelength in fresh muscle samples; while the H IIO II treated muscle samples do not exhibit NADH fluorescence. Raman spectroscopy may be used to develop a minimally invasive, in vivo optical biopsy method to measure the relative NAD and NADH levels in muscle tissues. This may help to detect diseases of muscle, including mitochondrial myopathies and muscular dystrophies.

  7. Muscle coordination during breaststroke swimming: Comparison between elite swimmers and beginners.

    PubMed

    Vaz, João R; Olstad, Bjørn Harald; Cabri, Jan; Kjendlie, Per-Ludvik; Pezarat-Correia, Pedro; Hug, François

    2016-10-01

    The present study aimed to compare muscle coordination strategies of the upper and lower limb muscles between beginners and elite breaststroke swimmers. Surface electromyography (EMG) of eight muscles was recorded in 16 swimmers (8 elite, 8 beginners) during a 25 m swimming breaststroke at 100% of maximal effort. A decomposition algorithm was used to identify the muscle synergies that represent the temporal and spatial organisation of muscle coordination. Between-groups indices of similarity and lag times were calculated. Individual muscle patterns were moderately to highly similar between groups (between-group indices range: 0.61 to 0.84). Significant differences were found in terms of lag time for pectoralis major (P < 0.05), biceps brachii, rectus femoris and tibialis anterior (P < 0.01), indicating an earlier activation for these muscles in beginners compared to elites (range: -13.2 to -3.8% of the swimming cycle). Three muscle synergies were identified for both beginners and elites. Although their composition was similar between populations, the third synergy exhibited a high within-group variability. Moderate to high indices of similarity were found for the shape of synergy activation coefficients (range: 0.63 to 0.88) but there was a significant backward shift (-8.4% of the swimming cycle) in synergy #2 for beginners compared to elites. This time shift suggested differences in the global arm-to-leg coordination. These results indicate that the synergistic organisation of muscle coordination during breaststroke swimming is not profoundly affected by expertise. However, specific timing adjustments were observed between lower and upper limbs.

  8. Sensitivity of subject-specific models to Hill muscle-tendon model parameters in simulations of gait.

    PubMed

    Carbone, V; van der Krogt, M M; Koopman, H F J M; Verdonschot, N

    2016-06-14

    Subject-specific musculoskeletal (MS) models of the lower extremity are essential for applications such as predicting the effects of orthopedic surgery. We performed an extensive sensitivity analysis to assess the effects of potential errors in Hill muscle-tendon (MT) model parameters for each of the 56 MT parts contained in a state-of-the-art MS model. We used two metrics, namely a Local Sensitivity Index (LSI) and an Overall Sensitivity Index (OSI), to distinguish the effect of the perturbation on the predicted force produced by the perturbed MT parts and by all the remaining MT parts, respectively, during a simulated gait cycle. Results indicated that sensitivity of the model depended on the specific role of each MT part during gait, and not merely on its size and length. Tendon slack length was the most sensitive parameter, followed by maximal isometric muscle force and optimal muscle fiber length, while nominal pennation angle showed very low sensitivity. The highest sensitivity values were found for the MT parts that act as prime movers of gait (Soleus: average OSI=5.27%, Rectus Femoris: average OSI=4.47%, Gastrocnemius: average OSI=3.77%, Vastus Lateralis: average OSI=1.36%, Biceps Femoris Caput Longum: average OSI=1.06%) and hip stabilizers (Gluteus Medius: average OSI=3.10%, Obturator Internus: average OSI=1.96%, Gluteus Minimus: average OSI=1.40%, Piriformis: average OSI=0.98%), followed by the Peroneal muscles (average OSI=2.20%) and Tibialis Anterior (average OSI=1.78%) some of which were not included in previous sensitivity studies. Finally, the proposed priority list provides quantitative information to indicate which MT parts and which MT parameters should be estimated most accurately to create detailed and reliable subject-specific MS models.

  9. COMPARISON OF TRUNK AND LOWER EXTREMITY MUSCLE ACTIVITY AMONG FOUR STATIONARY EQUIPMENT DEVICES: UPRIGHT BIKE, RECUMBENT BIKE, TREADMILL, AND ELLIPTIGO®

    PubMed Central

    Baker, Ryan; Gibson, Chris; Kearney, Andrew; Busemeyer, Tommy

    2016-01-01

    Background Stationary equipment devices are often used to improve fitness. The ElliptiGO® was recently developed that blends the elements of an elliptical trainer and bicycle, allowing reciprocal lower limb pedaling in an upright position. However, it is unknown whether the muscle activity used for the ElliptiGO® is similar to walking or cycling. To date, there is no information comparing muscle activity for exercise on the treadmill, stationary upright and recumbent bikes, and the ElliptiGO®. Purpose/Hypothesis The purpose of this study was to assess trunk and lower extremity muscle activity among treadmill walking, cycling (recumbent and upright) and the ElliptiGO® cycling. It was hypothesized that the ElliptiGO® and treadmill would elicit similar electromyographic muscle activity responses compared to the stationary bike and recumbent bike during an exercise session. Study Design Cohort, repeated measures Methods Twelve recreationally active volunteers participated in the study and were assigned a random order of exercise for each of the four devices (ElliptiGO®, stationary upright cycle ergometer, recumbent ergometer, and a treadmill). Two-dimensional video was used to monitor the start and stop of exercise and surface electromyography (SEMG) were used to assess muscle activity during two minutes of cycling or treadmill walking at 40-50% heart rate reserve (HRR). Eight muscles on the dominant limb were used for analysis: gluteus maximus (Gmax), gluteus medius (Gmed), biceps femoris (BF), lateral head of the gastrocnemius (LG), tibialis anterior (TA), rectus femoris (RF). Two trunk muscles were assessed on the same side; lumbar erector spinae at L3-4 level (LES) and rectus abdominus (RA). Maximal voluntary isometric contractions (MVIC) were determined for each muscle and SEMG data were expressed as %MVIC in order to normalize outputs. Results The %MVIC for RF during ElliptiGO® cycling was higher than recumbent cycling. The LG muscle activity was highest

  10. Design, Development and Testing of a Low-Cost sEMG System and Its Use in Recording Muscle Activity in Human Gait

    PubMed Central

    Supuk, Tamara Grujic; Skelin, Ana Kuzmanic; Cic, Maja

    2014-01-01

    Surface electromyography (sEMG) is an important measurement technique used in biomechanical, rehabilitation and sport environments. In this article the design, development and testing of a low-cost wearable sEMG system are described. The hardware architecture consists of a two-cascade small-sized bioamplifier with a total gain of 2,000 and band-pass of 3 to 500 Hz. The sampling frequency of the system is 1,000 Hz. Since real measured EMG signals are usually corrupted by various types of noises (motion artifacts, white noise and electromagnetic noise present at 50 Hz and higher harmonics), we have tested several denoising techniques, both on artificial and measured EMG signals. Results showed that a wavelet—based technique implementing Daubechies5 wavelet and soft sqtwolog thresholding is the most appropriate for EMG signals denoising. To test the system performance, EMG activities of six dominant muscles of ten healthy subjects during gait were measured (gluteus maximus, biceps femoris, sartorius, rectus femoris, tibialis anterior and medial gastrocnemius). The obtained EMG envelopes presented against the duration of gait cycle were compared favourably with the EMG data available in the literature, suggesting that the proposed system is suitable for a wide range of applications in biomechanics. PMID:24811078

  11. Design, development and testing of a low-cost sEMG system and its use in recording muscle activity in human gait.

    PubMed

    Supuk, Tamara Grujic; Skelin, Ana Kuzmanic; Cic, Maja

    2014-05-07

    Surface electromyography (sEMG) is an important measurement technique used in biomechanical, rehabilitation and sport environments. In this article the design, development and testing of a low-cost wearable sEMG system are described. The hardware architecture consists of a two-cascade small-sized bioamplifier with a total gain of 2,000 and band-pass of 3 to 500 Hz. The sampling frequency of the system is 1,000 Hz. Since real measured EMG signals are usually corrupted by various types of noises (motion artifacts, white noise and electromagnetic noise present at 50 Hz and higher harmonics), we have tested several denoising techniques, both on artificial and measured EMG signals. Results showed that a wavelet-based technique implementing Daubechies5 wavelet and soft sqtwolog thresholding is the most appropriate for EMG signals denoising. To test the system performance, EMG activities of six dominant muscles of ten healthy subjects during gait were measured (gluteus maximus, biceps femoris, sartorius, rectus femoris, tibialis anterior and medial gastrocnemius). The obtained EMG envelopes presented against the duration of gait cycle were compared favourably with the EMG data available in the literature, suggesting that the proposed system is suitable for a wide range of applications in biomechanics.

  12. The effects of aponeurosis geometry on strain injury susceptibility explored with a 3D muscle model.

    PubMed

    Rehorn, Michael R; Blemker, Silvia S

    2010-09-17

    In the musculoskeletal system, some muscles are injured more frequently than others. For example, the biceps femoris longhead (BFLH) is the most commonly injured hamstring muscle. It is thought that acute injuries result from large strains within the muscle tissue, but the mechanism behind this type of strain injury is still poorly understood. The purpose of this study was to build computational models to analyze the stretch distributions within the BFLH muscle and to explore the effects of aponeurosis geometry on the magnitude and location of peak stretches within the model. We created a three-dimensional finite element (FE) model of the BFLH based on magnetic resonance (MR) images. We also created a series of simplified models with a similar geometry to the MR-based model. We analyzed the stretches predicted by the MR-based model during lengthening contractions to determine the region of peak local fiber stretch. The peak along-fiber stretch was 1.64 and was located adjacent to the proximal myotendinous junction (MTJ). In contrast, the average along-fiber stretch across all the muscle tissue was 0.95. By analyzing the simple models, we found that varying the dimensions of the aponeuroses (width, length, and thickness) had a substantial impact on the location and magnitude of peak stretches within the muscle. Specifically, the difference in widths between the proximal and distal aponeurosis in the BFLH contributed most to the location and magnitude of peak stretch, as decreasing the proximal aponeurosis width by 80% increased peak average stretches along the proximal MTJ by greater than 60% while slightly decreasing stretches along the distal MTJ. These results suggest that the aponeurosis morphology of the BFLH plays a significant role in determining stretch distributions throughout the muscle. Furthermore, this study introduces the new hypothesis that aponeurosis widths may be important in determining muscle injury susceptibility.

  13. Muscle Activation and Estimated Relative Joint Force During Running with Weight Support on a Lower-Body Positive-Pressure Treadmill.

    PubMed

    Jensen, Bente R; Hovgaard-Hansen, Line; Cappelen, Katrine L

    2016-08-01

    Running on a lower-body positive-pressure (LBPP) treadmill allows effects of weight support on leg muscle activation to be assessed systematically, and has the potential to facilitate rehabilitation and prevent overloading. The aim was to study the effect of running with weight support on leg muscle activation and to estimate relative knee and ankle joint forces. Runners performed 6-min running sessions at 2.22 m/s and 3.33 m/s, at 100%, 80%, 60%, 40%, and 20% body weight (BW). Surface electromyography, ground reaction force, and running characteristics were measured. Relative knee and ankle joint forces were estimated. Leg muscles responded differently to unweighting during running, reflecting different relative contribution to propulsion and antigravity forces. At 20% BW, knee extensor EMGpeak decreased to 22% at 2.22 m/s and 28% at 3.33 m/s of 100% BW values. Plantar flexors decreased to 52% and 58% at 20% BW, while activity of biceps femoris muscle remained unchanged. Unweighting with LBPP reduced estimated joint force significantly although less than proportional to the degree of weight support (ankle). It was concluded that leg muscle activation adapted to the new biomechanical environment, and the effect of unweighting on estimated knee force was more pronounced than on ankle force.

  14. Phase- and Workload-Dependent Changes in Corticospinal Excitability to the Biceps and Triceps Brachii during Arm Cycling

    PubMed Central

    Spence, Alyssa-Joy; Alcock, Lynsey R.; Lockyer, Evan J.; Button, Duane C.; Power, Kevin E.

    2016-01-01

    This is the first study to examine corticospinal excitability (CSE) to antagonistic muscle groups during arm cycling. Transcranial magnetic stimulation (TMS) of the motor cortex and transmastoid electrical stimulation (TMES) of the corticospinal tract were used to assess changes in supraspinal and spinal excitability, respectively. TMS induced motor evoked potentials (MEPs) and TMES induced cervicomedullary evoked potentials (CMEPs) were recorded from the biceps and triceps brachii at two positions, mid-elbow flexion and extension, while cycling at 5% and 15% of peak power output. While phase-dependent modulation of MEP and CMEP amplitudes occurred in the biceps brachii, there was no difference between flexion and extension for MEP amplitudes in the triceps brachii and CMEP amplitudes were higher during flexion than extension. Furthermore, MEP amplitudes in both biceps and triceps brachii increased with increased workload. CMEP amplitudes increased with higher workloads in the triceps brachii, but not biceps brachii, though the pattern of change in CMEPs was similar to MEPs. Differences between changes in CSE between the biceps and triceps brachii suggest that these antagonistic muscles may be under different neural control during arm cycling. Putative mechanisms are discussed. PMID:27983685

  15. Effects of hamstring stretching on passive muscle stiffness vary between hip flexion and knee extension maneuvers.

    PubMed

    Miyamoto, N; Hirata, K; Kanehisa, H

    2017-01-01

    The purpose of this study was to examine whether the effects of hamstring stretching on the passive stiffness of each of the long head of the biceps femoris (BFl), semitendinosus (ST), and semimembranosus (SM) vary between passive knee extension and hip flexion stretching maneuvers. In 12 male subjects, before and after five sets of 90 s static stretching, passive lengthening measurements where knee or hip joint was passively rotated to the maximal range of motion (ROM) were performed. During the passive lengthening, shear modulus of each muscle was measured by ultrasound shear wave elastography. Both stretching maneuvers significantly increased maximal ROM and decreased passive torque at a given joint angle. Passive knee extension stretching maneuver significantly reduced shear modulus at a given knee joint angle in all of BFl, ST, and SM. In contrast, the stretching effect by passive hip flexion maneuver was significant only in ST and SM. The present findings indicate that the effects of hamstring stretching on individual passive muscles' stiffness vary between passive knee extension and hip flexion stretching maneuvers. In terms of reducing the muscle stiffness of BFl, stretching of the hamstring should be performed by passive knee extension rather than hip flexion.

  16. Effect of an Eight-Week Ballroom Dancing Program on Muscle Architecture in Older Adults Females.

    PubMed

    Cepeda, Christina C P; Lodovico, Angélica; Fowler, Neil; Rodacki, André L F

    2015-10-01

    Aging is related to a progressive remodeling of the neuromuscular system, which includes muscle mass, strength, and power reductions. This study investigated the effect of an eight-week dance program on fascicle pennation angle, fascicle length, and thickness of the vastus lateralis (VL), tibialis anterior (TA), biceps femoris (BF), and gastrocnemius medialis (GM) muscles using ultrasound images. Thirty-four healthy older women were randomly assigned to either a dancing (DG: n = 19, 69.1 ± 6.5 years, 72.5 ± 11.7 kg) or control group (CG: n = 15, 71.5 ± 7.4 years, 70.9 ± 9.3 kg). After training, the DG showed greater (p < .05) thickness for VL (16%), TA (17%), BF (19%), and GM (15%); pennation angle for VL (21%), TA (23%), BF (21%), and GM (17%); and fascicle length for VL (11%), TA (12%), BF (10%), and GM (10%). These findings suggest that dance training was effective to change the lower limb muscle architecture in older female adults.

  17. Effects of the lower extremities muscle activation during muscular strength training on an unstable platform with magneto-rheological dampers

    NASA Astrophysics Data System (ADS)

    Piao, YongJun; Choi, YounJung; Kim, JungJa; Kwan, TaeKyu; Kim, Nam-Gyun

    2009-03-01

    Adequate postural balance depends on the spatial and temporal integration of vestibular, visual, and somatosensory information. Especially, the musculoskeletal function (range of joint, flexibility of spine, muscular strength) is essential in maintaining the postural balance. Muscular strength training methods include the use of commercialized devices and repeatable resistance training tools (rubber band, ball, etc). These training systems cost high price and can't control of intensity. Thus we suggest a new training system which can adjust training intensity and indicate the center of pressure of a subject while the training was passively controlled by applying controlled electric current to the Magneto- Rheological damper. And we performed experimental studies on the muscular activities in the lower extremities during maintaining, moving and pushing exercises on an unstable platform with Magneto rheological dampers. A subject executed the maintaining, moving and pushing exercises which were displayed in a monitor. The electromyographic signals of the eight muscles in lower extremities were recorded and analyzed in the time and frequency domain: the muscles of interest were rectus femoris, biceps femoris, tensor fasciae latae, vastus lateralis, vastus medialis, gastrocnemius, tibialis anterior, and soleus. The experimental results showed the difference of muscular activities at the four moving exercises and the nine maintaining exercises. The rate of the increase in the muscular activities was affected by the condition of the unstable platform with MR dampers for the maintaining and moving exercises. The experimental results suggested the choice of different maintaining and moving exercises could selectively train different muscles with varying intensity. Furthermore, the findings also suggested the training using this system can improve the ability of postural balance.

  18. Disorders of the long head of the biceps tendon.

    PubMed

    Mellano, Chris R; Shin, Jason J; Yanke, Adam B; Verma, Nikhil N

    2015-01-01

    The functional importance of the long head of the biceps tendon is a source of debate. Despite the controversy concerning its functional role, the long head of the biceps tendon is a recognized pain generator in the shoulder. Because long head of the biceps tendinopathy is commonly associated with other shoulder pathologies, a thorough assessment and examination are critical to making the correct diagnosis and choosing a management plan. If nonsurgical treatment has failed, biceps tenotomy and biceps tenodesis can provide pain relief. Biceps tenodesis is reserved for young, higher demand patients; requires more rehabilitation time; and has a higher cost. All-arthroscopic proximal tenodesis and distal open subpectoral tenodesis have advantages and disadvantages. Although recent midterm reports suggest slightly better revision and complication rates with subpectoral tenodesis, more studies are needed to verify these findings. Persistent shoulder symptoms after biceps tenodesis commonly occur secondary to missed or untreated associated shoulder pathologies but also may result from mechanical failure of the tenodesis.

  19. Muscle Contraction Velocity: A Suitable Approach to Analyze the Functional Adaptations in Elite Soccer Players.

    PubMed

    Loturco, Irineu; Pereira, Lucas A; Kobal, Ronaldo; Kitamura, Katia; Ramírez-Campillo, Rodrigo; Zanetti, Vinicius; Abad, Cesar C Cal; Nakamura, Fabio Y

    2016-09-01

    Tensiomyography (TMG) has been used as a simple and non-invasive tool to assess the mechanical properties of skeletal muscles. The TMG-derived velocity of contraction (Vc), which can be calculated from the ratio between maximal radial displacement and the sum of contraction time and delay time, has been proposed for evaluating athletes. However, its sensitivity to training effects and possible relation with changes in soccer players' neuromuscular performance have not yet been addressed. To test this possibility, twenty-two male Brazilian elite soccer players were assessed using TMG-derived Vc, unloaded squat jump, countermovement jump and drop jump at 45 cm, loaded jump squat and linear (20 m) and change of direction (COD) sprint tests, prior to and after an 8-week period, between two consecutive official tournaments, during which the concurrency between endurance and strength-power training commonly impairs neuromuscular capacities. Magnitude-based inference was used to detect meaningful training effects. From pre- to post-tests, it was observed likely to almost certainly improvements in all modes of jumping tests. In addition, we could verify decrements in the 20-m and COD sprint performances, which were rated as very likely and almost certainly, respectively. Finally, both rectus femoris and biceps femoris muscles presented a likely reduction in Vc. Therefore, chronic decreases in sprinting speed are possibly accompanied by a reduced TMG-derived Vc. From a practical standpoint, the TMG-derived Vc can be used to monitor negative specific-soccer training effects related to potential impairments in maximum speed.

  20. Comparative Analysis of Muscle Transcriptome between Pig Genotypes Identifies Genes and Regulatory Mechanisms Associated to Growth, Fatness and Metabolism

    PubMed Central

    Ayuso, Miriam; Fernández, Almudena; Núñez, Yolanda; Benítez, Rita; Isabel, Beatriz; Barragán, Carmen; Fernández, Ana Isabel; Rey, Ana Isabel; Medrano, Juan F.; Cánovas, Ángela; González-Bulnes, Antonio; López-Bote, Clemente; Ovilo, Cristina

    2015-01-01

    Iberian ham production includes both purebred (IB) and Duroc-crossbred (IBxDU) Iberian pigs, which show important differences in meat quality and production traits, such as muscle growth and fatness. This experiment was conducted to investigate gene expression differences, transcriptional regulation and genetic polymorphisms that could be associated with the observed phenotypic differences between IB and IBxDU pigs. Nine IB and 10 IBxDU pigs were slaughtered at birth. Morphometric measures and blood samples were obtained and samples from Biceps femoris muscle were employed for compositional and transcriptome analysis by RNA-Seq technology. Phenotypic differences were evident at this early age, including greater body size and weight in IBxDU and greater Biceps femoris intramuscular fat and plasma cholesterol content in IB newborns. We detected 149 differentially expressed genes between IB and IBxDU neonates (p < 0.01 and Fold-Change > 1. 5). Several were related to adipose and muscle tissues development (DLK1, FGF21 or UBC). The functional interpretation of the transcriptomic differences revealed enrichment of functions and pathways related to lipid metabolism in IB and to cellular and muscle growth in IBxDU pigs. Protein catabolism, cholesterol biosynthesis and immune system were functions enriched in both genotypes. We identified transcription factors potentially affecting the observed gene expression differences. Some of them have known functions on adipogenesis (CEBPA, EGRs), lipid metabolism (PPARGC1B) and myogenesis (FOXOs, MEF2D, MYOD1), which suggest a key role in the meat quality differences existing between IB and IBxDU hams. We also identified several polymorphisms showing differential segregation between IB and IBxDU pigs. Among them, non-synonymous variants were detected in several transcription factors as PPARGC1B and TRIM63 genes, which could be associated to altered gene function. Taken together, these results provide information about candidate

  1. Mapping of intramuscular tenderness and muscle fiber orientation of muscles in the beef round.

    PubMed

    Senaratne, L S; Calkins, C R; de Mello, A S; Pokharel, S; Hinkle, J B

    2010-09-01

    Intramuscular tenderness variation and muscle fiber orientation of beef M. adductor femoris (AF), M. biceps femoris (BF), M. gracilis (GL), M. pectineus (PT), M. sartorius (SR), M. semimembranosus (SM), M. semitendinosus (SO), M. vastus intermedius (VI), M. vastus medialis (VM), and M. vastus lateralis (VL) were investigated. The USDA Choice boxed beef subprimals were purchased and aged for 14 d from boxed date. The AF, BF, GL, PT, SR, SM, SO, VI, VM, and VL (n = 10 each) were fabricated from subprimals. Crust-frozen AF, BF, SO, SM, and VL were cut into 2.54-cm steaks perpendicular to the long axis and grilled (71 degrees C). The PT, SR, VI, and VM were grilled (71 degrees C) as whole muscles, whereas the GL was grilled after cutting into anterior and posterior regions. Grilled muscles were cut into equal size sections perpendicular to long axis of muscles. Location-specific cores were prepared from each steak/section, and Warner-Bratzler shear force (WBSF) was measured. The muscle fiber orientations of BF, PT, and VI were bipennate, SR and SO were fusiform, and AD, SM, VL, GL, and VM were unipennate. The overall mean WBSF values for BF, SO, AF, SM, PT, SR, GL, VI, VM, and VL were 5.62, 4.86, 4.18, 4.90, 3.76, 4.44, 4.75, 4.78, 4.24, and 6.53 kg, respectively. Based on WBSF values, PT was tender, BF and VL were tough, and VM, VI, SM, GL SR, AF, and SO were intermediate. The first 2 proximal steaks of long head BF were more tender than the rest (P < 0.05). In the SO, the tenderness decreased from the middle of the muscle to both ends (P < 0.05). The anterior sides of the long head BF and SO were tougher than their posterior sides (P < 0.05).The first 4 steaks of the SM were more tender than the rest of the muscle (P < 0.05). There was a significant tenderness increment from the middle of the AF and SR to both ends of each muscle (P < 0.05). The medial side of the VI was more tender than its lateral side (P < 0.05). The VM had its smallest shear force value at the

  2. Intra- and intermuscular variation in human quadriceps femoris architecture assessed in vivo

    PubMed Central

    Blazevich, Anthony J; Gill, Nicholas D; Zhou, Shi

    2006-01-01

    Despite the functional importance of the human quadriceps femoris in movements such as running, jumping, lifting and climbing, and the known effects of muscle architecture on muscle function, no research has fully described the complex architecture of this muscle group. We used ultrasound imaging techniques to measure muscle thickness, fascicle angle and fascicle length at multiple regions of the four quadriceps muscles in vivo in 31 recreationally active, but non-strength-trained adult men and women. Our analyses revealed a reasonable similarity in the superficial quadriceps muscles, which is suggestive of functional similarity (at least during the uni-joint knee extension task) given that they act via a common tendon. The deep vastus intermedius (VI) is architecturally dissimilar and therefore probably serves a different function(s). Architecture varies significantly along the length of the superficial muscles, which has implications for the accuracy of models that assume a constant intramuscular architecture. It might also have consequences for the efficiency of intra- and intermuscular force transmission. Our results provide some evidence that subjects with a given architecture of one superficial muscle, relative to the rest of the subject sample, also have a similar architecture in other superficial muscles. However, this is not necessarily true for vastus lateralis (VL), and was not the case for VI. Therefore, the relative architecture of one muscle cannot confidently be used to estimate the relative architecture of another. To confirm this, we calculated a value of whole quadriceps architecture by four different methods. Regardless of the method used, we found that the absolute or relative architecture of one muscle could not be used as an indicator of whole quadriceps architecture, although vastus medialis, possibly in concert with VL and the anterior portion of VI, could be used to provide a useful snapshot. Importantly, our estimates of whole quadriceps

  3. Warner-Bratzler shear evaluations of 40 bovine muscles.

    PubMed

    Belew, J B; Brooks, J C; McKenna, D R; Savell, J W

    2003-08-01

    Forty muscles from each of 20 beef carcass sides were used to perform Warner-Bratzler shear (WBS) force determinations for within and among muscle effects. The M. triceps brachii differed (P <0.05) in WBS values between the caput longum and caput laterale, and the M. gluteobiceps differed (P <0.05) in WBS values between the vertebral, cranial, and caudal portions. The M. trapezius did not differ between the pars cervicalis and pars thoracica. Larger muscles were evaluated for location effects within muscles. The M. pectoralis profundus, M. infraspinatus, M. triceps brachii (caput longum), psoas major, and M. semimembranosus all had significant location effects. Muscles were allocated into "very tender," "tender," "intermediate" or "tough" categories. Those muscles considered "very tender" (WBS <3.2 kg) were the diaphragm (outside skirt or wing of diaphragm), M. spinalis, M. infraspinatus, M. iliacus, M. psoas major, M. serratus ventralis, M. biceps brachii, M. obliquus internus abdominis, and M. vastus medius. Muscles considered "tender" (3.2 kg femoris, M. gluteus medius, M. gracilis, M. complexus, M. rectus abdominis, M. rhomboideus, and M. triceps brachii. Muscles classified as "intermediate" (3.9 kg Muscles classed as "tough" (WBS > 4.6 kg) were the M. extensor carpi radialis, M. trapezius, M. brachialis, M. pectoralis profundus, and M. flexor digitorum superficialis (hind limb). The diaphragm muscle was the most tender (WBS=2.03 kg), and the M. flexor digitorum superficialis was the toughest (WBS=7.74 kg

  4. Does feed restriction and re-alimentation differently affect lipid content and metabolism according to muscle type in pigs (Sus scrofa)?

    PubMed

    Gondret, Florence; Lebret, Bénédicte

    2007-06-01

    This study aimed to investigate whether feed restriction and re-alimentation differently affect lipid content and activities of lipogenic or catabolic enzymes according to muscle types in pigs. At around 28 kg body mass (BW), sixty pigs (n=30 per group) were allocated to either ad libitum (AL) or restricted/re-feeding (RA) regimens. After feed restriction (80 kg BW), lipid content was reduced (P<0.01) in the oxidative rhomboideus (RH) as in the glycolytic biceps femoris (BF) muscles of RA pigs compared with AL pigs. Lower activities (P<0.05) of the lipogenic enzymes fatty acid synthase (FAS) and malic enzyme (ME) were observed in the RH but not in the BF of RA vs. AL pigs. After re-feeding (110 kg BW), lipid content was restored in the RH, but was still 12% lower (P<0.05) in the BF of RA compared with AL pigs. In the RH, the trend for an enhanced FAS activity and for a smaller weight-related decrease of ME activity in RA pigs than AL pigs during re-feeding, may have contributed to the muscle fat recovery observed in the RA pigs. In the BF, higher oxidative enzyme activities (P<0.10) in RA pigs compared to AL pigs might explain the incomplete lipid recovery observed after re-feeding in the former animals. In conclusion, metabolic activities in response to restriction and re-feeding differed according to muscle metabolic type.

  5. Acute Calcific Tendinitis of the Rectus Femoris: A Case Series

    PubMed Central

    Kobayashi, Hideo; Kaneko, Haruka; Homma, Yasuhiro; Baba, Tomonori; Kaneko, Kazuo

    2015-01-01

    Introduction: Periarticular calcific tendinitis is a common cause of Orthopedic outpatient referral. Calcific tendinitis of the rectus femoris, however, is very rare and not well known. Due to its rarity, correct diagnosis and prompt treatment are not fully understood. Case Report: Two females (38 and 40 years old) of acute calcific tendinitis of the rectus femoris with the good clinical course without any operative treatment were presented. The pain was managed with oral non-steroidal antiinflammatory drugs and/or local steroid injection. Interval radiographic assessment showed complete resorption of the calcification. Conclusion: Establishing the correct diagnosis and initiating prompt treatment are shown to be important in achieving resolution of symptoms and in avoiding unnecessary investigations. PMID:27299063

  6. Myostatin regulates fiber-type composition of skeletal muscle by regulating MEF2 and MyoD gene expression.

    PubMed

    Hennebry, Alex; Berry, Carole; Siriett, Victoria; O'Callaghan, Paul; Chau, Linda; Watson, Trevor; Sharma, Mridula; Kambadur, Ravi

    2009-03-01

    Myostatin (Mstn) is a secreted growth factor belonging to the tranforming growth factor (TGF)-beta superfamily. Inactivation of murine Mstn by gene targeting, or natural mutation of bovine or human Mstn, induces the double muscling (DM) phenotype. In DM cattle, Mstn deficiency increases fast glycolytic (type IIB) fiber formation in the biceps femoris (BF) muscle. Using Mstn null ((-/-)) mice, we suggest a possible mechanism behind Mstn-mediated fiber-type diversity. Histological analysis revealed increased type IIB fibers with a concomitant decrease in type IIA and type I fibers in the Mstn(-/-) tibialis anterior and BF muscle. Functional electrical stimulation of Mstn(-/-) BF revealed increased fatigue susceptibility, supporting increased type IIB fiber content. Given the role of myocyte enhancer factor 2 (MEF2) in oxidative type I fiber formation, MEF2 levels in Mstn(-/-) tissue were quantified. Results revealed reduced MEF2C protein in Mstn(-/-) muscle and myoblast nuclear extracts. Reduced MEF2-DNA complex was also observed in electrophoretic mobility-shift assay using Mstn(-/-) nuclear extracts. Furthermore, reduced expression of MEF2 downstream target genes MLC1F and calcineurin were found in Mstn(-/-) muscle. Conversely, Mstn addition was sufficient to directly upregulate MLC promoter-enhancer activity in cultured myoblasts. Since high MyoD levels are seen in fast fibers, we analyzed MyoD levels in the muscle. In contrast to MEF2C, MyoD levels were increased in Mstn(-/-) muscle. Together, these results suggest that while Mstn positively regulates MEF2C levels, it negatively regulates MyoD expression in muscle. We propose that Mstn could regulate fiber-type composition by regulating the expression of MEF2C and MyoD during myogenesis.

  7. The Effects of Inclination (Up and Down) of the Treadmill on the Electromyogram Activities of the Forelimb and Hind limb Muscles at a Walk and a Trot in Thoroughbred Horses

    PubMed Central

    TAKAHASHI, Toshiyuki; MATSUI, Akira; MUKAI, Kazutaka; OHMURA, Hajime; HIRAGA, Atsushi; AIDA, Hiroko

    2014-01-01

    ABSTRACT It is important to know the effects of the inclination of a slope on the activity of each muscle, because training by running on a sloped track is commonly used for Thoroughbred racehorses. The effects of incline (from −6 to +6%) on the forelimbs and hind limbs during walking and trotting on a treadmill were evaluated by an integrated electromyogram (iEMG). The muscle activities in the forelimbs (5 horses) and hind limbs (4 horses) were measured separately. Two stainless steel wires were inserted into each of the brachiocephalicus (Bc), biceps brachii (BB), splenius (Sp), and pectoralis descendens (PD) in the forelimb experiment and into the longissimus dorsi (LD), vastus lateralis (VL), gluteus medius (GM), and biceps femoris (BF) in the hind limb experiment. The EMG recordings were taken at a sampling rate of 1,000 Hz. At a walk, the iEMG values for the forelimb were not significantly different under any of the inclinations. In the hind limb, the iEMG values for the GM and BF significantly decreased as the inclination decreased. At a trot, the iEMG values for the Bc in the forelimb significantly decreased as the inclination of the treadmill decreased. In the hind limb, the iEMG values for the LD, GM, and BF significantly decreased as the inclination decreased. Uphill exercise increased the iEMG values for the Bc, LD, GM, and BF, while downhill exercise resulted in little increase in the iEMG values. It was concluded that the effects of inclination on the muscle activities were larger for the uphill exercises, and for the hind limb muscles compared with the forelimb muscles. PMID:25558180

  8. The Effects of Inclination (Up and Down) of the Treadmill on the Electromyogram Activities of the Forelimb and Hind limb Muscles at a Walk and a Trot in Thoroughbred Horses.

    PubMed

    Takahashi, Toshiyuki; Matsui, Akira; Mukai, Kazutaka; Ohmura, Hajime; Hiraga, Atsushi; Aida, Hiroko

    2014-01-01

    It is important to know the effects of the inclination of a slope on the activity of each muscle, because training by running on a sloped track is commonly used for Thoroughbred racehorses. The effects of incline (from -6 to +6%) on the forelimbs and hind limbs during walking and trotting on a treadmill were evaluated by an integrated electromyogram (iEMG). The muscle activities in the forelimbs (5 horses) and hind limbs (4 horses) were measured separately. Two stainless steel wires were inserted into each of the brachiocephalicus (Bc), biceps brachii (BB), splenius (Sp), and pectoralis descendens (PD) in the forelimb experiment and into the longissimus dorsi (LD), vastus lateralis (VL), gluteus medius (GM), and biceps femoris (BF) in the hind limb experiment. The EMG recordings were taken at a sampling rate of 1,000 Hz. At a walk, the iEMG values for the forelimb were not significantly different under any of the inclinations. In the hind limb, the iEMG values for the GM and BF significantly decreased as the inclination decreased. At a trot, the iEMG values for the Bc in the forelimb significantly decreased as the inclination of the treadmill decreased. In the hind limb, the iEMG values for the LD, GM, and BF significantly decreased as the inclination decreased. Uphill exercise increased the iEMG values for the Bc, LD, GM, and BF, while downhill exercise resulted in little increase in the iEMG values. It was concluded that the effects of inclination on the muscle activities were larger for the uphill exercises, and for the hind limb muscles compared with the forelimb muscles.

  9. Effect of feeding palm oil by-products based diets on muscle fatty acid composition in goats.

    PubMed

    Abubakr, Abdelrahim; Alimon, Abdul Razak; Yaakub, Halimatun; Abdullah, Norhani; Ivan, Michael

    2015-01-01

    The present study aims to evaluate the effects of feeding palm oil by-products based diets on different muscle fatty acid profiles in goats. Thirty-two Cacang × Boer goats were randomly assigned to four dietary treatments: (1) control diet (CD), (2) 80% decanter cake diet (DCD), (3) 80% palm kernel cake diet (PKCD) and (4) CD plus 5% palm oil (PO) supplemented diet (CPOD). After 100 days of feeding, four goats from each group were slaughtered and longissimus dorsi (LD), infraspinatus (IS) and biceps femoris (BF) were sampled for analysis of fatty acids. Goats fed the PKCD had higher (P<0.05) concentration of lauric acid (C12:0) than those fed the other diets in all the muscles tested. Compared to the other diets, the concentrations of palmitic acid (C16:0) and stearic acid (C18:0) were lower (P<0.05) and that of linoleic acid (C18:2 n-6) was higher (P<0.05) in the muscles from goats fed the CD. It was concluded that palm kernel cake and decanter cake can be included in the diet of goats up to 80% with more beneficial than detrimental effects on the fatty acid profile of their meat.

  10. Inhibition by aminoguanidine of glucose-derived collagen cross-linking in skeletal muscle of broiler breeder hens.

    PubMed

    Klandorf, H; Zhou, Q; Sams, A R

    1996-03-01

    Aminoguanidine (AG) is a nucleophilic compound that inhibits nonenzymatic, glucose-derived collagen cross-linking in animal tissues. Whether AG can attenuate the accumulation of collagen cross-links in the Biceps femoris muscle of 64-wk-old broiler breeder hens as well as improve meat quality, was investigated. Eighty-four broiler breeder hens (30-wk-old) were divided into four equal groups. Each group was assigned randomly to diets supplemented with 0. 200, 400, or 800 ppm AG, respectively. Birds were fed individually, 150 g diet/d. After feeding AG for 34 wk, six birds from each group were killed and samples from the leg muscle were analyzed for changes in collagen content. Aminoguanidine decreased (P < 0.05) glucose-derived collagen cross-links in skeletal muscle as measured by fluorescence and collagen solubility. Insoluble collagen fraction decreased with increasing AG dosage, whereas acid-soluble and pepsin-soluble fractions increased with increasing AG dosage. Aminoguanidine did not affect shear force. In agreement with studies on animals with diabetes, AG is a potent inhibitor of glucose-derived cross-linking in chickens although the results from the measurements of shear force do not support its used for improving carcass quality in spent hens.

  11. Effect of Feeding Palm Oil By-Products Based Diets on Muscle Fatty Acid Composition in Goats

    PubMed Central

    Abubakr, Abdelrahim; Alimon, Abdul Razak; Yaakub, Halimatun; Abdullah, Norhani; Ivan, Michael

    2015-01-01

    The present study aims to evaluate the effects of feeding palm oil by-products based diets on different muscle fatty acid profiles in goats. Thirty-two Cacang × Boer goats were randomly assigned to four dietary treatments: (1) control diet (CD), (2) 80% decanter cake diet (DCD), (3) 80% palm kernel cake diet (PKCD) and (4) CD plus 5% palm oil (PO) supplemented diet (CPOD). After 100 days of feeding, four goats from each group were slaughtered and longissimus dorsi (LD), infraspinatus (IS) and biceps femoris (BF) were sampled for analysis of fatty acids. Goats fed the PKCD had higher (P<0.05) concentration of lauric acid (C12:0) than those fed the other diets in all the muscles tested. Compared to the other diets, the concentrations of palmitic acid (C16:0) and stearic acid (C18:0) were lower (P<0.05) and that of linoleic acid (C18:2 n-6) was higher (P<0.05) in the muscles from goats fed the CD. It was concluded that palm kernel cake and decanter cake can be included in the diet of goats up to 80% with more beneficial than detrimental effects on the fatty acid profile of their meat. PMID:25789610

  12. Lipoma arborescens of the biceps tendon sheath.

    PubMed

    White, Eric A; Omid, Reza; Matcuk, George R; Domzalski, Jerome T; Fedenko, Alexander N; Gottsegen, Christopher J; Forrester, Deborah M; Patel, Dakshesh B

    2013-10-01

    Lipoma arborescens, described as lipomatous infiltration and distention of synovial villi resulting in a frond-like appearance, most frequently affects the suprapatellar recess of the knee. While there have been reports of this entity involving the upper extremity joints, bursa, and tendon sheaths, we present the first reported case of lipoma arborescens isolated to the biceps tendon sheath. We describe imaging and histologic findings with clinical correlation.

  13. Endovascular Repair of a Large Profunda Femoris Artery Pseudoaneurysm

    PubMed Central

    Khalid, Ahsan Syed; Ghanem, Omar M.; Mojtaba Gashti, Seyed

    2014-01-01

    Profunda femoris artery aneurysms and pseudoaneurysms are a rare cause of peripheral arterial aneurysms but their risk of rupture is quite high. We have presented a case of a left lower leg pseudoaneurysm. We have shown that endovascular repair with angioplasty and stenting is a suitable treatment method for such a pseudoaneurysm. Due to the limited data on this disease, we suggest multi-institute collaboration to identify and standardize management for the treatment. PMID:24716098

  14. Ruptures of the distal biceps tendon.

    PubMed

    Ward, James P; Shreve, Mark C; Youm, Thomas; Strauss, Eric J

    2014-01-01

    Distal biceps ruptures occur most commonly in middle-aged males and result from eccentric contraction of the biceps tendon. The injury typically presents with pain and a tearing sensation in the antecubital fossa with resultant weakness in flexion and supination strength. Physical exam maneuvers and diagnostic imaging aid in determining the diagnosis. Nonoperative management is reserved for elderly, low demand patients, while operative intervention is generally pursued for younger patients and can consist of nonanatomic repair to the brachialis or anatomic repair to the radial tuberosity. Anatomic repair through a one-incision or two-incision approach is commonplace, while the nonanatomic repairs are rarely performed. No clear advantage exists in operative management with a one-incision versus two-incision techniques. Chronic ruptures present a more difficult situation, and allograft augmentation is often necessary. Common complications after repair include transient nerve palsy, which often resolves, and heterotopic ossification. Despite these possible complications, most studies suggest that better patient outcomes are obtained with operative, anatomic reattachment of the distal biceps tendon.

  15. Quantification of Electromyographic Activity During REM Sleep in Multiple Muscles in REM Sleep Behavior Disorder

    PubMed Central

    Frauscher, Birgit; Iranzo, Alex; Högl, Birgit; Casanova-Molla, Jordi; Salamero, Manel; Gschliesser, Viola; Tolosa, Eduardo; Poewe, Werner; Santamaria, Joan

    2008-01-01

    Study Objectives: The aim of our study was to determine which muscle or combination of muscles (either axial or limb muscles, lower or upper limb muscles, or proximal or distal limb muscles) provides the highest rates of rapid eye movement (REM) sleep phasic electromyographic (EMG) activity seen in patients with REM sleep behavior disorder (RBD). Setting: Two university hospital sleep disorders centers. Participants: Seventeen patients with idiopathic RBD (n = 8) and RBD secondary to Parkinson disease (n = 9). Interventions: Not applicable. Measurements and Results: Patients underwent polysomnography, including EMG recording of 13 different muscles. Phasic EMG activity in REM sleep was quantified for each muscle separately. A mean of 1459.6 ± 613.8 three-second REM sleep mini-epochs were scored per patient. Mean percentages of phasic EMG activity were mentalis (42 ± 19), flexor digitorum superficialis (29 ± 13), extensor digitorum brevis (23 ± 12), abductor pollicis brevis (22 ± 11), sternocleidomastoid (22 ± 12), deltoid (19 ± 11), biceps brachii (19 ± 11), gastrocnemius (18 ± 9), tibialis anterior (right, 17 ± 12; left, 16 ± 10), rectus femoris (left, 11 ± 6; right, 9 ± 6), and thoraco-lumbar paraspinal muscles (6 ± 5). The mentalis muscle provided significantly higher rates of excessive phasic EMG activity than all other muscles but only detected 55% of all the mini-epochs with phasic EMG activity. Simultaneous recording of the mentalis, flexor digitorum superficialis, and extensor digitorum brevis muscles detected 82% of all mini-epochs containing phasic EMG activity. This combination provided higher rates of EMG activity than any other 3-muscle combination. Excessive phasic EMG activity was more frequent in distal than in proximal muscles, both in upper and lower limbs. Conclusion: Simultaneous recording of the mentalis, flexor digitorum superficialis, and extensor digitorum brevis muscles provided the highest rates of REM sleep phasic EMG

  16. Effects of supplemental vitamin D3 on feed intake, carcass characteristics, tenderness, and muscle properties of beef steers.

    PubMed

    Karges, K; Brooks, J C; Gill, D R; Breazile, J E; Owens, F N; Morgan, J B

    2001-11-01

    Research was conducted to determine the effects of supplemental dietary vitamin D3 on DMI, carcass traits, Warner Bratzler shear (WBS) force, calpastatin activity, plasma minerals, pH (0, 3, 12, and 24 h after slaughter), water-holding capacity (WHC), and sensory characteristics of three muscles. Pre-slaughter vitamin D3 treatments included no supplemental vitamin D3, 6 x 106 IU (MIU) of vitamin D3 for 4 d, or 6 MIU of vitamin D3 for 6 d. Cattle were slaughtered and carcasses were chilled for 48 h before removal of steaks from the longissimus, gluteus medius, and biceps femoris muscles. Steaks were aged at 2 degrees C for 7, 14, or 21 d before cooking to a final internal temperature of 70 degrees C for WBS and sensory panel analysis. Dry matter intake was lower for steers supplemented with vitamin D3 for 4 or 6 d. Live and carcass weights were lower (P < 0.05) in steers supplemented with vitamin D3. Supplementing 6 MIU/6 d of vitamin D3 decreased (P < 0.05) WBS values of gluteus steaks (pooled over aging times). Longissimus steaks from steers supplemented with vitamin D3 for 6 d had lower (P < 0.05) WBS force values than these steaks from control steers or steers fed vitamin D3 for 4 d at 7 d postmortem. Biceps femoris steaks from steers receiving vitamin D3 for 4 d had higher WBS values than steaks from control steers at 14 and 21 d postmortem. Feeding vitamin D3 at 6 MIU for 6 d decreased (P < 0.05) the percentage of steaks that had WBS values > or = 3.86 kg for all steaks. Feeding vitamin D3 had no effect on palatability traits evaluated by trained panelists. Blood Ca concentrations were greater (P < 0.05) when vitamin D3 was fed and with increased vitamin D3 feeding time. Feeding vitamin D3 for 6 d (vs 4 d) delayed pH decline for all muscle types after 0, 3, and 12 h postmortem. Water-holding capacity was increased (P > 0.02) after 0 h, 24 h, and 21 d postmortem when vitamin D3 was fed and was greater at 0 and 24 h if vitamin D3 was fed for 6 d rather than 4 d

  17. Influence of angular velocity on vastus lateralis and rectus femoris oxygenation dynamics during knee extension exercises.

    PubMed

    Denis, Romain; Wilkinson, Jennifer; De Vito, Giuseppe

    2011-09-01

    The purpose of this study was to investigate whether changes in angular velocity would alter vastus lateralis (VL) and rectus femoris (RF) oxygenation status during maximal isokinetic knee extension exercises. Eleven recreationally active male participants randomly performed ten maximal knee extensions at 30, 60, 120 and 240° s(-1). Tissue oxygenation index (TOI) and total haemoglobin concentration ([tHb]) were acquired from the VL and RF muscles by means of near-infrared spectroscopy (NIRS). Breath-by-breath pulmonary oxygen consumption (VO(2p)) was recorded throughout the tests. Peak torque and VO(2p) significantly decreased as a function of velocity (P<0·05). Interestingly, RF and VL TOI significantly increased as a function of velocity (P<0·05), whereas [tHb] significantly decreased as a function of velocity (P<0·05). A greater number of muscle fibre recruited at slow velocity, where the torque and VO(2p) were the highest, might explain the lower VL and RF TOI observed herein. Furthermore, the increase in local blood flow (suggested by [tHb] changes) during isokinetic knee extension exercises performed at slow angular velocity might have been induced by a higher intramuscular pressure during the contraction phases as well as a greater microcirculatory vasodilatation during relaxation phases. Implementing slow-velocity isokinetic exercises in rehabilitation or other training programmes could delay the short-term anoxia generated by such exercises and result in muscle metabolism enhancement.

  18. Long head of the biceps tendinopathy: diagnosis and management.

    PubMed

    Nho, Shane J; Strauss, Eric J; Lenart, Brett A; Provencher, Matthew T; Mazzocca, Augustus D; Verma, Nikhil N; Romeo, Anthony A

    2010-11-01

    Tendinopathy of the long head of the biceps brachii encompasses a spectrum of pathology ranging from inflammatory tendinitis to degenerative tendinosis. Disorders of the long head of the biceps often occur in conjunction with other shoulder pathology. A thorough patient history, physical examination, and radiographic evaluation are necessary for diagnosis. Nonsurgical management, including rest, nonsteroidal anti-inflammatory drugs, physical therapy, and injections, is attempted first in patients with mild disease. Surgical management is indicated for refractory or severe disease. In addition to simple biceps tenotomy, a variety of tenodesis techniques has been described. Open biceps tenodesis has been used historically. However, promising results have recently been reported with arthroscopic tenodesis.

  19. Muscle Activation During Exercise in Severe Acute Hypoxia: Role of Absolute and Relative Intensity

    PubMed Central

    Torres-Peralta, Rafael; Losa-Reyna, José; González-Izal, Miriam; Perez-Suarez, Ismael; Calle-Herrero, Jaime; Izquierdo, Mikel

    2014-01-01

    Abstract Torres-Peralta, Rafael, José Losa-Reyna, Miriam González-Izal, Ismael Perez-Suarez, Jaime Calle-Herrero, Mikel Izquierdo, and José A.L. Calbet. Muscle activation during exercise in severe acute hypoxia: Role of absolute and relative intensity. High Alt Med Biol 15:472–482, 2014.—The aim of this study was to determine the influence of severe acute hypoxia on muscle activation during whole body dynamic exercise. Eleven young men performed four incremental cycle ergometer tests to exhaustion breathing normoxic (FIo2=0.21, two tests) or hypoxic gas (FIo2=0.108, two tests). Surface electromyography (EMG) activities of rectus femoris (RF), vastus medialis (VL), vastus lateralis (VL), and biceps femoris (BF) were recorded. The two normoxic and the two hypoxic tests were averaged to reduce EMG variability. Peak Vo2 was 34% lower in hypoxia than in normoxia (p<0.05). The EMG root mean square (RMS) increased with exercise intensity in all muscles (p<0.05), with greater effect in hypoxia than in normoxia in the RF and VM (p<0.05), and a similar trend in VL (p=0.10). At the same relative intensity, the RMS was greater in normoxia than in hypoxia in RF, VL, and BF (p<0.05), with a similar trend in VM (p=0.08). Median frequency increased with exercise intensity (p<0.05), and was higher in hypoxia than in normoxia in VL (p<0.05). Muscle contraction burst duration increased with exercise intensity in VM and VL (p<0.05), without clear effects of FIo2. No significant FIo2 effects on frequency domain indices were observed when compared at the same relative intensity. In conclusion, muscle activation during whole body exercise increases almost linearly with exercise intensity, following a muscle-specific pattern, which is adjusted depending on the FIo2 and the relative intensity of exercise. Both VL and VM are increasingly involved in power output generation with the increase of intensity and the reduction in FIo2. PMID:25225839

  20. Evaluation of Electromyographic Biofeedback for the Quadriceps Femoris: A Systematic Review

    PubMed Central

    Wasielewski, Noah J.; Parker, Tonya M.; Kotsko, Kevin M.

    2011-01-01

    Objective: To critically review evidence for the effectiveness of electromyographic biofeedback (EMGB) of the quadriceps femoris muscle in treating various knee conditions. Data Sources: Databases used to locate randomized controlled trials included PubMed (1980–2010), Cumulative Index of Nursing and Allied Health Literature (CINAHL, 1995–2007), Web of Science (1986–2010), SPORTDiscus (1990–2007), and Physiotherapy Evidence Database (PEDro). Key words were knee and biofeedback. Study Selection: The criteria for selection were clinical randomized controlled trials in which EMGB of the quadriceps femoris was used for various knee conditions of musculoskeletal origin. Trials were excluded because of research designs other than randomized controlled trials, articles published in a non-English language, inclusion of healthy research participants, inability to identify EMGB as the source of clinical improvement, and lack of pain, functional outcome, or quadriceps torque as outcome measures. Data Extraction: Twenty specific data points were abstracted from each clinical trial under the broad categories of attributes of the patient and injury, treatment variables for the EMGB group, treatment variables for the control group, and attributes of the research design. Data Synthesis: Eight trials yielded a total of 319 participants with patellofemoral pain syndrome (n = 86), anterior cruciate ligament reconstruction (n = 52), arthroscopic surgery (n = 91), or osteoarthritis (n = 90). The average methodologic score of the included studies was 4.6/10 based on PEDro criteria. Pooled analyses demonstrated heterogeneity of the included studies, rendering the interpretation of the pooled data inappropriate. The EMGB appeared to benefit short-term postsurgical pain or quadriceps strength in 3 of 4 postsurgical investigations but was ineffective for chronic knee conditions such as patellofemoral pain and osteoarthritis in all 4 studies. Because the findings are based on limited

  1. Complications of Distal Biceps Tendon Repair

    PubMed Central

    Amin, Nirav H.; Volpi, Alex; Lynch, T. Sean; Patel, Ronak M.; Cerynik, Douglas L.; Schickendantz, Mark S.; Jones, Morgan H.

    2016-01-01

    Background: Anatomic reinsertion of the distal biceps is critical for restoring flexion and supination strength. Single- and double-incision surgical techniques have been reported, analyzing complications and outcomes measures. Which technique results in superior clinical outcomes and the lowest associated complications remains unclear. Hypothesis: We hypothesized that rerupture rates would be similar between the 2 techniques, while nerve complications would be higher for the single-incision technique and heterotopic ossification would be more frequent with the double-incision technique. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: A systematic review was conducted using the PubMed, MEDLINE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), SPORTSDiscus, and the Cochrane Central Register of Controlled Trials databases to identify articles reporting distal biceps ruptures up to August 2013. We included English-language articles on adult patients with a minimum of 3 cases reporting single- and double-incision techniques. Frequencies of each complication as a percentage of total cases were calculated. Fisher exact tests were used to test the association between frequencies for each repair method, with P < .05 considered statistically significant. Odds ratios with 95% CIs were also computed. Results: A total of 87 articles met the inclusion criteria. Lateral antebrachial cutaneous nerve neurapraxia was the most common complication in the single-incision group, occurring in 77 of 785 cases (9.8%). Heterotopic ossification was the most common complication in the double-incision group, occurring in 36 of 498 cases (7.2%). Conclusion: The overall frequency of reported complications is higher for single-incision distal biceps repair than for double-incision repair. The frequencies of rerupture and nerve complications are both higher for single-incision repairs while the frequency of heterotopic ossification is higher for

  2. Effect of stretching on agonist-antagonist muscle activity and muscle force output during single and multiple joint isometric contractions.

    PubMed

    McBride, J M; Deane, R; Nimphius, S

    2007-02-01

    Eight moderately active male subjects where tested for peak force in an isometric knee extension test and peak force and rate of force development in an isometric squat test. Both tests where performed at a 100 degrees knee angle and average integrated electromyography (IEMG) was measured from the vastus medialis (VM), vastus lateralis (VL) and biceps femoris (BF) muscles. Subjects performed the two conditions, stretching (S) or control (C) in a randomized order. Subjects where tested for baseline strength measures in both the isometric knee extension and isometric squat and then either stretched or sat quietly for 10 min. Following S or C subjects where then tested at six time points. Following S peak force in the isometric knee extension was significantly (P < or = 0.05) less than C at 1, 2, 8 and 16 min post. No significant difference in peak force was found between S and C in the isometric squat. However, following S the rate of force development in the isometric squat was significantly less than C at immediately post. No significant differences where observed in IEMG of the VM or VL between S and C in either the isometric knee extension or isometric squat. However, IEMG significantly decreased in the BF at 1 min post after S in comparison with C in both the isometric knee extension and isometric squat. Stretching appears to decrease muscle force output in a single joint isometric contraction and rate of force development in a multiple joint isometric contraction. Possible changes in agonist-antagonist muscle activity patterns need to be further examined.

  3. Proximal Biceps Tendon and Rotator Cuff Tears.

    PubMed

    Virk, Mandeep S; Cole, Brian J

    2016-01-01

    The long head of biceps tendon (LHBT) is frequently involved in rotator cuff tears and can cause anterior shoulder pain. Tendon hypertrophy, hourglass contracture, delamination, tears, and tendon instability in the bicipital groove are common macroscopic pathologic findings affecting the LHBT in the presence of rotator cuff tears. Failure to address LHBT disorders in the setting of rotator cuff tear can result in persistent shoulder pain and poor satisfaction after rotator cuff repair. Tenotomy or tenodesis of the LHBT are effective options for relieving pain arising from the LHBT in the setting of reparable and selected irreparable rotator cuff tears.

  4. Recumbent vs. upright bicycles: 3D trajectory of body centre of mass, limb mechanical work, and operative range of propulsive muscles.

    PubMed

    Telli, Riccardo; Seminati, Elena; Pavei, Gaspare; Minetti, Alberto Enrico

    2017-03-01

    Recumbent bicycles (RB) are high performance, human-powered vehicles. In comparison to normal/upright bicycles (NB) the RB may allow individuals to reach higher speeds due to aerodynamic advantages. The purpose of this investigation was to compare the non-aerodynamic factors that may potentially influence the performance of the two bicycles. 3D body centre of mass (BCoM) trajectory, its symmetries, and the components of the total mechanical work necessary to sustain cycling were assessed through 3D kinematics and computer simulations. Data collected at 50, 70, 90 110 rpm during stationary cycling were used to drive musculoskeletal modelling simulation and estimate muscle-tendon length. Results demonstrated that BCoM trajectory, confined in a 15-mm side cube, changed its orientation, maintaining a similar pattern across all cadences in both bicycles. RB displayed a reduced additional mechanical external power (16.1 ± 9.7 W on RB vs. 20.3 ± 8.8 W on NB), a greater symmetry on the progression axis, and no differences in the internal mechanical power compared to NB. Simulated muscle activity revealed small significant differences for only selected muscles. On the RB, quadriceps and gluteus demonstrated greater shortening, while biceps femoris, iliacus, and psoas exhibited greater stretch; however, aerodynamics still remains the principal benefit.

  5. Calcitonin gene-related peptide produces skeletal muscle vasodilation following antidromic stimulation of unmyelinated afferents in the dorsal root in rats.

    PubMed

    Sato, A; Sato, Y; Shimura, M; Uchida, S

    2000-04-07

    In anesthetized rats, the contribution of calcitonin gene-related peptide (CGRP) to antidromic vasodilation of skeletal muscle blood flow (MBF) following electrical stimulation of muscle afferent was investigated by measuring biceps femoris MBF using laser Doppler flowmetry. Repetitive antidromic electrical stimulation of unmyelinated C fibers in ipsilateral dorsal roots at the 3rd-5th lumbar segments for 30 s caused an increase in MBF for 3-15 min (mean 4.5 min) without significant change in systemic arterial blood pressure. The increase in skeletal MBF started about 10 s after the onset of stimulation, and peaked at approximately 130% of the control value at about 30 s after the end of the 30 s period of stimulation. The MBF response was totally abolished by topical application of hCGRP (8-37), a CGRP receptor antagonist. It is concluded that antidromic vasodilation in skeletal muscles following stimulation of unmyelinated C afferents in dorsal roots is independent of systemic blood pressure and is mediated essentially by CGRP. It is suggested that this CGRP-related antidromic vasodilation may be important in the clinical improvement of skeletal MBF produced by physical therapy, e.g. acupuncture.

  6. Upregulation of skeletal muscle PGC-1α through the elevation of cyclic AMP levels by Cyanidin-3-glucoside enhances exercise performance

    PubMed Central

    Matsukawa, Toshiya; Motojima, Hideko; Sato, Yuki; Takahashi, Shinya; Villareal, Myra O.; Isoda, Hiroko

    2017-01-01

    Regular exercise and physical training enhance physiological capacity and improve metabolic diseases. Skeletal muscles require peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) in the process of their adaptation to exercise owing to PGC-1α’s ability to regulate mitochondrial biogenesis, angiogenesis, and oxidative metabolism. Cyanidin-3-glucoside (Cy3G) is a natural polyphenol and a nutraceutical factor, which has several beneficial effects on human health. Here, the effect of Cy3G on exercise performance and the underlying mechanisms involved were investigated. ICR mice were given Cy3G (1 mg/kg, orally) everyday and made to perform weight-loaded swimming exercise for 15 days. The endurance of mice orally administered with Cy3G was improved, enabling them to swim longer (time) and while the levels of exercise-induced lactate and fatigue markers (urea nitrogen, creatinine and total ketone bodies) were reduced. Additionally, the expression of lactate metabolism-related genes (lactate dehydrogenase B and monocarboxylate transporter 1) in gastrocnemius and biceps femoris muscles was increased in response to Cy3G-induced PGC-1α upregulation. In vitro, using C2C12 myotubes, Cy3G-induced elevation of intracellular cyclic AMP levels increased PGC-1α expression via the Ca2+/calmodulin-dependent protein kinase kinase pathway. This study demonstrates that Cy3G enhances exercise performance by activating lactate metabolism through skeletal muscle PGC-1α upregulation. PMID:28317895

  7. Motion and Muscle Activity Are Affected by Instability Location During a Squat Exercise.

    PubMed

    Nairn, Brian C; Sutherland, Chad A; Drake, Janessa D M

    2017-03-01

    Nairn, BC, Sutherland, CA, and Drake, JDM. Motion and muscle activity are affected by instability location during a squat exercise. J Strength Cond Res 31(3): 677-685, 2017-Squat exercise training using instability devices has become increasingly popular for a multitude of reasons. Many devices generate instability at the feet and provide a bottom-up perturbation; however, the effect of a top-down instability device during a squat remains unclear. To induce instability at the upper body, a water-filled cylinder called the Attitube was used. This study analyzed the effects of instability location (top-down, bottom-up, and no instability) during a squat exercise in terms of kinematics and muscle activation. Ten male participants were instrumented with 75 reflective markers to track kinematics of the ankle, knee, hip, trunk, and the Bar/Attitube, and electromyography was recorded from 12 muscles bilaterally. Squats were performed with an Olympic bar on a stable surface, an Olympic bar on a BOSU ball (BALL, bottom-up), and the Attitube on solid ground (TUBE, top-down). The TUBE showed up to 1.5 times reduction in erector spinae activation and up to 1.5 times less trunk flexion while being performed at a slower velocity. There was also higher abdominal activation in the TUBE, with up to 2.8 times greater oblique activation compared with the stable condition. The BALL increased ankle eversion and knee flexion with higher muscle activation in gastrocnemius, biceps femoris, and quadriceps. Overall, changing the location of instability during a squat changed the motion and muscle activation patterns of the trunk and lower extremities. This provides information for future research into rehabilitation, learning proper squat technique, and for specific training scenarios.

  8. Activation and aponeurosis morphology affect in vivo muscle tissue strains near the myotendinous junction.

    PubMed

    Fiorentino, Niccolo M; Epstein, Frederick H; Blemker, Silvia S

    2012-02-23

    Hamstring strain injury is one of the most common injuries in athletes, particularly for sports that involve high speed running. The aims of this study were to determine whether muscle activation and internal morphology influence in vivo muscle behavior and strain injury susceptibility. We measured tissue displacement and strains in the hamstring muscle injured most often, the biceps femoris long head muscle (BFLH), using cine DENSE dynamic magnetic resonance imaging. Strain measurements were used to test whether strain magnitudes are (i) larger during active lengthening than during passive lengthening and (ii) larger for subjects with a relatively narrow proximal aponeurosis than a wide proximal aponeurosis. Displacement color maps showed higher tissue displacement with increasing lateral distance from the proximal aponeurosis for both active lengthening and passive lengthening, and higher tissue displacement for active lengthening than passive lengthening. First principal strain magnitudes were averaged in a 1cm region near the myotendinous junction, where injury is most frequently observed. It was found that strains are significantly larger during active lengthening (0.19 SD 0.09) than passive lengthening (0.13 SD 0.06) (p<0.05), which suggests that elevated localized strains may be a mechanism for increased injury risk during active as opposed to passive lengthening. First principal strains were higher for subjects with a relatively narrow aponeurosis width (0.26 SD 0.15) than wide (0.14 SD 0.04) (p<0.05). This result suggests that athletes who have BFLH muscles with narrow proximal aponeuroses may have an increased risk for BFLH strain injuries.

  9. Pre- and early-postnatal nutrition modify gene and protein expressions of muscle energy metabolism markers and phospholipid Fatty Acid composition in a muscle type specific manner in sheep.

    PubMed

    Hou, Lei; Kongsted, Anna H; Ghoreishi, Seyed M; Takhtsabzy, Tasnim K; Friedrichsen, Martin; Hellgren, Lars I; Kadarmideen, Haja N; Vaag, Allan; Nielsen, Mette O

    2013-01-01

    We previously reported that undernutrition in late fetal life reduced whole-body insulin sensitivity in adult sheep, irrespective of dietary exposure in early postnatal life. Skeletal muscle may play an important role in control of insulin action. We therefore studied a range of putative key muscle determinants of insulin signalling in two types of skeletal muscles (longissimus dorsi (LD) and biceps femoris (BF)) and in the cardiac muscle (ventriculus sinister cordis (VSC)) of sheep from the same experiment. Twin-bearing ewes were fed either 100% (NORM) or 50% (LOW) of their energy and protein requirements during the last trimester of gestation. From day-3 postpartum to 6-months of age (around puberty), twin offspring received a high-carbohydrate-high-fat (HCHF) or a moderate-conventional (CONV) diet, whereafter all males were slaughtered. Females were subsequently raised on a moderate diet and slaughtered at 2-years of age (young adults). The only long-term consequences of fetal undernutrition observed in adult offspring were lower expressions of the insulin responsive glucose transporter 4 (GLUT4) protein and peroxisome proliferator-activated receptor gamma, coactivator 1α (PGC1α) mRNA in BF, but increased PGC1α expression in VSC. Interestingly, the HCHF diet in early postnatal life was associated with somewhat paradoxically increased expressions in LD of a range of genes (but not proteins) related to glucose uptake, insulin signalling and fatty acid oxidation. Except for fatty acid oxidation genes, these changes persisted into adulthood. No persistent expression changes were observed in BF and VSC. The HCHF diet increased phospholipid ratios of n-6/n-3 polyunsaturated fatty acids in all muscles, even in adults fed identical diets for 1½ years. In conclusion, early postnatal, but not late gestation, nutrition had long-term consequences for a number of determinants of insulin action and metabolism in LD. Tissues other than muscle may account for reduced whole

  10. Ultrasound Assessment of the Rectus Femoris Cross-Sectional Area: Subject Position Implications.

    PubMed

    Hacker, Eileen Danaher; Peters, Tara; Garkova, Miglena

    2016-09-01

    Ultrasonic measurement of the rectus femoris (RF) is a novel, proxy measure for muscle strength. The impact of hip flexion/head of bed positioning on RF cross-sectional area (CSA) has not been fully explored. This study describes and compares differences in RF CSA across four degrees of hip flexion. This repeated-measures, comparative study enrolled healthy, pre-menopausal women (n = 20). RF CSA of the dominant leg was measured using the SonoSite M-Turbo ultrasound system with the head of bed at 0°, 20°, 30°, and 60°. One-way repeated measures indicated significant differences in RF CSA, F(3, 17) = 14.18, p < .001, with variation in hip flexion/head of bed elevation and significant RF CSA differences between: (a) 0° and 20°, (b) 0° and 30°, (c) 0° and 60°, and (d) 20° and 60°. Standardizing patient positioning when conducting ultrasonic measurement of RF CSA is vital for researchers who assess muscle mass.

  11. Effect of elbow flexion on the proximity of the PIN during 2-incision distal biceps repair.

    PubMed

    Jones, Jason A; Jones, Christopher M; Grossman, Mark G

    2013-07-01

    The posterior interosseous nerve (PIN) is at risk for injury during surgical dissection for distal biceps repair, yet the optimal position of elbow flexion to avoid a PIN injury has never been established for the 2-incision approach. The purpose of this study was to determine the proximity of the PIN to the radial tuberosity during surgical dissection in different degrees of elbow flexion. Ten cadaveric specimens with an intact elbow and forearm were dissected in full pronation using a modified Boyd-Anderson approach. Half of the dissections were completed in 90° of flexion and the other half were completed in maximal flexion. To simulate the location of the PIN during a single-incision biceps repair, the distance of the PIN to the radial tuberosity was recorded in full extension and supination. Results from these measurements were assessed for differences using paired t tests, with differences deemed significant for P values less than .05. The PIN was not identified in any of the 2-incision surgical dissections. Based on these findings, the proximity of the PIN to the radial tuberosity is not significantly affected by the degree of elbow flexion in the muscle-splitting 2-incision approach. In addition, a safe zone exists for avoiding PIN injury in a single-incision technique for distal biceps repair because a drill bit exiting the radial tuberosity greater than 1 cm in a distal-radial direction would place the PIN at risk.

  12. Building the BICEP3 Test Cryostat

    NASA Astrophysics Data System (ADS)

    Walker, Samantha; Kuo, Chao-Lin; Thompson, Keith L.; Grayson, James; Karpel, Ethan; Monticue, Val; Kuo Group/Bicep3 Collaboration Team

    2016-03-01

    BICEP3, a ground-based telescope stationed in the South Pole, currently employs a cryostat to observe the polarization of the Cosmic Microwave Background, the earliest light in the Universe, by using devices that take advantage of the superconductivity transition of titanium. The cryostat consists of staggered temperature stages at 300 K, 50 K, 4 K, 2 K, 350 mK, and 250 mK that are maintained by both a pulse tube and three stage helium (He4-He3-He3) sorption refrigerator. However, currently the helium refrigerator is experiencing unanticipated heat loading which is decreasing the fridge cycle hold time and thus the number of hours that BICEP3 can observe for in a given period of time. To address this issue, this past summer I worked at Stanford University to construct a thermally-similar cryostat that will be used to test the thermal conductivities of its various internal components at subKelvin temperatures and determine the source of this heat loading.

  13. Long term betaine supplementation regulates genes involved in lipid and cholesterol metabolism of two muscles from an obese pig breed.

    PubMed

    Albuquerque, A; Neves, José A; Redondeiro, M; Laranjo, M; Félix, M R; Freitas, Amadeu; Tirapicos, José L; Martins, José M

    2017-02-01

    This study evaluates the effects of betaine supplementation (1gkg(-1) for 20weeks) on the regulation of genes involved in lipid and cholesterol metabolism of Longissimus lumborum and Biceps femoris from obese Alentejano pigs. Betaine supplementation led to an increase in total cholesterol in both muscles, complementing results previously published indicating a significant increase on the intramuscular lipid content. The expression of twelve genes involved in lipogenesis, lipolysis/FA oxidation, FA transport, and cholesterol metabolism, as well as two transcription factors were also evaluated. Genes related to lipid and cholesterol synthesis plus FA transport were consistently up-regulated in both muscles of betaine fed pigs. On the other hand, genes related to lipolysis/FA oxidation were not affected or down-regulated by betaine supplementation. Our data suggest that the underlying mechanism regulating IMF and cholesterol accumulation in Alentejano pigs supplemented with betaine is associated with the up-regulation of genes involved in lipid synthesis, FA transport, and cholesterol synthesis.

  14. MRI analysis of structural changes in skeletal muscles and surrounding tissues following long-term walking exercise with training equipment.

    PubMed

    Nakai, Ryusuke; Azuma, Takashi; Sudo, Mai; Urayama, Shin-Ichi; Takizawa, Osamu; Tsutsumi, Sadami

    2008-09-01

    Muscular recovery after exercise is an important topic in sports medicine, and accurate and quantitative measurements of changes in muscle are required to assess muscular recovery. In the present study, we report a new analytical method to measure muscular changes quantitatively. The technique consists of three independent methods: image processing of two-dimensional MR images, morphological analysis using three-dimensional MR images, and diffusion tensor MRI. Using this method, we investigated changes in the quadriceps and biceps femoris and gluteus maximus muscles and surrounding tissues before and after 1 mo of exercise wearing training equipment. The subjects were 21 healthy adult female volunteers, 14 of whom wore training equipment and 7 who wore normal equipment. The percentage of adipose tissue in muscle after exercise in subjects who wore training equipment was on average 4.4% (P < 0.001) lower than that before exercise, and the peak point of the dorsal hip after exercise with use of the equipment was on average 10.8 mm higher than that before exercise. Further, the fractional anisotropy of water diffusion in muscles increased by an average of 0.039 (P < 0.001) after exercise with use of training equipment. In contrast, there was no significant difference before and after exercise in subjects who wore normal equipment. These results show that walking exercise while wearing training equipment thickens and tightens the muscular fiber tissues. This noninvasive measurement approach may allow quantitation of the athletic ability of the muscles, which is not measured conventionally, and is an effective method for analyzing skeletal muscles.

  15. The effects of performing a one-legged bridge with hip abduction and use of a sling on trunk and lower extremity muscle activation in healthy adults

    PubMed Central

    Choi, Kyuju; Bak, Jongwoo; Cho, Minkwon; Chung, Yijung

    2016-01-01

    [Purpose] This study investigated the changes in the muscle activities of the trunk and lower limbs of healthy adults during a one-legged bridge exercise using a sling, and with the addition of hip abduction. [Subjects and Methods] Twenty-seven healthy individuals participated in this study (14 males and 13 females). The participants were instructed to perform the bridge exercises under five different conditions. Trunk and lower limb muscle activation of the erector spinae (ES), external oblique (EO), gluteus maximus (GM), and biceps femoris (BF) was measured using surface electromyography. Data analysis was performed using the mean scores of three trials performed under each condition. [Results] There was a significant increase in bilateral EO and contralateral GM with the one-legged bridge compared with the one-legged bridge with sling exercise. Muscle activation of the ipsilateral GM and BF was significantly less during the one-legged bridge exercise compared to the one-legged bridge with sling exercise, and was significantly greater during the one-legged bridge with hip abduction compared to the one-legged bridge exercise. The muscle activation of the contralateral GM and BF was significantly greater with the one-legged bridge with hip abduction compared to the general bridge exercise. [Conclusion] With the one-legged bridge with hip abduction, the ipsilateral EO, GM and BF muscle activities were significantly greater than those of the one-legged bridge exercise. The muscle activation of all trunk and contralateral lower extremity muscles increased with the bridge with sling exercises compared with general bridge exercises. PMID:27799708

  16. Rupture of the lateral lobe of the biceps brachii tendon in an Arabian horse.

    PubMed

    Spadari, A; Spinella, G; Romagnoli, N; Valentini, S

    2009-01-01

    Rupture of the lateral lobe of the proximal tendon of the biceps brachii muscle was diagnosed in an Arabian horse. To the authors' knowledge, this is the only report of this condition in horses. Although clinical signs were helpful in the identification of the location of disease, ultrasonographic examination was a more definitive and non- invasive means of diagnosing the pathological condition. Bursoscopic examination of the intertubercular bursa was also useful in obtaining confirmation of the diagnosis, and for debridement and lavage of the bursa.

  17. Squeezing the Muscle: Compression Clothing and Muscle Metabolism during Recovery from High Intensity Exercise

    PubMed Central

    Sperlich, Billy; Born, Dennis-Peter; Kaskinoro, Kimmo; Kalliokoski, Kari K.; Laaksonen, Marko S.

    2013-01-01

    The purpose of this experiment was to investigate skeletal muscle blood flow and glucose uptake in m. biceps (BF) and m. quadriceps femoris (QF) 1) during recovery from high intensity cycle exercise, and 2) while wearing a compression short applying ∼37 mmHg to the thigh muscles. Blood flow and glucose uptake were measured in the compressed and non-compressed leg of 6 healthy men by using positron emission tomography. At baseline blood flow in QF (P = 0.79) and BF (P = 0.90) did not differ between the compressed and the non-compressed leg. During recovery muscle blood flow was higher compared to baseline in both compressed (P<0.01) and non-compressed QF (P<0.001) but not in compressed (P = 0.41) and non-compressed BF (P = 0.05; effect size = 2.74). During recovery blood flow was lower in compressed QF (P<0.01) but not in BF (P = 0.26) compared to the non-compressed muscles. During baseline and recovery no differences in blood flow were detected between the superficial and deep parts of QF in both, compressed (baseline P = 0.79; recovery P = 0.68) and non-compressed leg (baseline P = 0.64; recovery P = 0.06). During recovery glucose uptake was higher in QF compared to BF in both conditions (P<0.01) with no difference between the compressed and non-compressed thigh. Glucose uptake was higher in the deep compared to the superficial parts of QF (compression leg P = 0.02). These results demonstrate that wearing compression shorts with ∼37 mmHg of external pressure reduces blood flow both in the deep and superficial regions of muscle tissue during recovery from high intensity exercise but does not affect glucose uptake in BF and QF. PMID:23613756

  18. BICEP3 performance overview and planned Keck Array upgrade

    NASA Astrophysics Data System (ADS)

    Grayson, J. A.; Ade, P. A. R.; Ahmed, Z.; Alexander, K. D.; Amiri, M.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Boenish, H.; Bowens-Rubin, R.; Buder, I.; Bullock, E.; Buza, V.; Connors, J.; Filippini, J. P.; Fliescher, S.; Halpern, M.; Harrison, S.; Hilton, G. C.; Hristov, V. V.; Hui, H.; Irwin, K. D.; Kang, J.; Karkare, K. S.; Karpel, E.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Megerian, K. G.; Monticue, V.; Namikawa, T.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W.; Pryke, C.; Reintsema, C. D.; Richter, S.; Schwarz, R.; Sorenson, C.; Sheehy, C. D.; Staniszewski, Z. K.; Steinbach, B.; Teply, G. P.; Thompson, K. L.; Tolan, J. E.; Tucker, C.; Turner, A. D.; Vieregg, A. G.; Wandui, A.; Weber, A. C.; Wiebe, D. V.; Willmert, J.; Wu, W. L. K.; Yoon, K. W.

    2016-07-01

    Bicep3 is a 520mm aperture, compact two-lens refractor designed to observe the polarization of the cosmic microwave background (CMB) at 95 GHz. Its focal plane consists of modularized tiles of antenna-coupled transition edge sensors (TESs), similar to those used in Bicep2 and the Keck Array. The increased per-receiver optical throughput compared to Bicep2/Keck Array, due to both its faster f=1:7 optics and the larger aperture, more than doubles the combined mapping speed of the Bicep/Keck program. The Bicep3 receiver was recently upgraded to a full complement of 20 tiles of detectors (2560 TESs) and is now beginning its second year of observation (and first science season) at the South Pole. We report on its current performance and observing plans. Given its high per-receiver throughput while maintaining the advantages of a compact design, Bicep3- class receivers are ideally suited as building blocks for a 3rd-generation CMB experiment, consisting of multiple receivers spanning 35 GHz to 270 GHz with total detector count in the tens of thousands. We present plans for such an array, the new "BICEP Array" that will replace the Keck Array at the South Pole, including design optimization, frequency coverage, and deployment/observing strategies.

  19. MRI-Based Regional Muscle Use during Hamstring Strengthening Exercises in Elite Soccer Players.

    PubMed

    Mendez-Villanueva, Alberto; Suarez-Arrones, Luis; Rodas, Gil; Fernandez-Gonzalo, Rodrigo; Tesch, Per; Linnehan, Richard; Kreider, Richard; Di Salvo, Valter

    2016-01-01

    The present study examined site-specific hamstring muscles use with functional magnetic resonance imaging (MRI) in elite soccer players during strength training. Thirty-six players were randomized into four groups, each performing either Nordic hamstring, flywheel leg-curl, Russian belt or the hip-extension conic-pulley exercise. The transverse relaxation time (T2) shift from pre- to post-MRI were calculated for the biceps femoris long (BFl) and short (BFs) heads, semitendinosus (ST) and semimembranosus (SM) muscles at proximal, middle and distal areas of the muscle length. T2 values increased substantially after flywheel leg-curl in all regions of the BFl (from 9±8 to 16±8%), BFs (41±6-71±11%), and ST (60±1-69±7%). Nordic hamstring induced a substantial T2 increase in all regions of the BFs (13±8-16±5%) and ST (15±7-17±5%). T2 values after the Russian belt deadlift substantially increased in all regions of the BFl (6±4-7±5%), ST (8±3-11±2%), SM (6±4-10±4%), and proximal and distal regions of BFs (6±6-8±5%). T2 values substantially increased after hip-extension conic-pulley only in proximal and middle regions of BFl (11±5-7±5%) and ST (7±3-12±4%). The relevance of such MRI-based inter- and intra-muscle use in designing more effective resistance training for improving hamstring function and preventing hamstring injuries in elite soccer players should be explored with more mechanistic studies.

  20. MRI-Based Regional Muscle Use during Hamstring Strengthening Exercises in Elite Soccer Players

    PubMed Central

    Mendez-Villanueva, Alberto; Suarez-Arrones, Luis; Rodas, Gil; Fernandez-Gonzalo, Rodrigo; Tesch, Per; Linnehan, Richard; Kreider, Richard; Di Salvo, Valter

    2016-01-01

    The present study examined site-specific hamstring muscles use with functional magnetic resonance imaging (MRI) in elite soccer players during strength training. Thirty-six players were randomized into four groups, each performing either Nordic hamstring, flywheel leg-curl, Russian belt or the hip-extension conic-pulley exercise. The transverse relaxation time (T2) shift from pre- to post-MRI were calculated for the biceps femoris long (BFl) and short (BFs) heads, semitendinosus (ST) and semimembranosus (SM) muscles at proximal, middle and distal areas of the muscle length. T2 values increased substantially after flywheel leg-curl in all regions of the BFl (from 9±8 to 16±8%), BFs (41±6–71±11%), and ST (60±1–69±7%). Nordic hamstring induced a substantial T2 increase in all regions of the BFs (13±8–16±5%) and ST (15±7–17±5%). T2 values after the Russian belt deadlift substantially increased in all regions of the BFl (6±4–7±5%), ST (8±3–11±2%), SM (6±4–10±4%), and proximal and distal regions of BFs (6±6–8±5%). T2 values substantially increased after hip-extension conic-pulley only in proximal and middle regions of BFl (11±5–7±5%) and ST (7±3–12±4%). The relevance of such MRI-based inter- and intra-muscle use in designing more effective resistance training for improving hamstring function and preventing hamstring injuries in elite soccer players should be explored with more mechanistic studies. PMID:27583444

  1. Comparison of kinetic variables and muscle activity during a squat vs. a box squat.

    PubMed

    McBride, Jeffrey M; Skinner, Jared W; Schafer, Patrick C; Haines, Tracie L; Kirby, Tyler J

    2010-12-01

    The purpose of this investigation was to determine if there was a difference in kinetic variables and muscle activity when comparing a squat to a box squat. A box squat removes the stretch-shortening cycle component from the squat, and thus, the possible influence of the box squat on concentric phase performance is of interest. Eight resistance trained men (Height: 179.61 ± 13.43 cm; Body Mass: 107.65 ± 29.79 kg; Age: 24.77 ± 3.22 years; 1 repetition maximum [1RM]: 200.11 ± 58.91 kg) performed 1 repetition of squats and box squats using 60, 70, and 80% of their 1RM in a randomized fashion. Subjects completed the movement while standing on a force plate and with 2 linear position transducers attached to the bar. Force and velocity were used to calculate power. Peak force and peak power were determined from the force-time and power-time curves during the concentric phase of the lift. Muscle activity (electromyography) was recorded from the vastus lateralis, vastus medialis, biceps femoris, and longissimus. Results indicate that peak force and peak power are similar between the squat and box squat. However, during the 70% of 1RM trials, the squat resulted in a significantly lower peak force in comparison to the box squat (squat = 3,269 ± 573 N, box squat = 3,364 ± 575 N). In addition, during the 80% of 1RM trials, the squat resulted in significantly lower peak power in comparison to the box squat (squat = 2,050 ± 486 W, box squat = 2,197 ± 544 W). Muscle activity was generally higher during the squat in comparison to the box squat. In conclusion, minimal differences were observed in kinetic variables and muscle activity between the squat and box squat. Removing the stretch-shortening cycle during the squat (using a box) appears to have limited negative consequences on performance.

  2. BICEP2 in corpuscular description of inflation

    SciTech Connect

    Dvali, G.; Gomez, C.

    2015-03-15

    A corpuscular quantum description of inflation shows that there is no fundamental problem with trans-Planckian excursions of the inflaton field up to about 100 Planck masses, with the upper bound coming from the corpuscular quantum effects. In this description, the r parameter measures the ratio of occupation numbers of gravitons versus inflatons, which, according to BICEP2, was roughly a half at the time of 60 e-foldings prior to the end of inflation. We stress that in a non-Wilsonian UV self-completion of gravity, any trans-Planckian mode coupled to the inflaton is a black hole. Unlike the Wilsonian case, integrating them out gives an exponentially suppressed effect and is unable to prevent trans-Planckian excursions of the inflaton field.

  3. Bifurcated intraarticular long head of biceps tendon

    PubMed Central

    Pandey, Vivek; van Laarhoven, Simon Nurettin; Arora, Gaurav; Rao, Sripathi

    2014-01-01

    Though rare, many anomalous origins of long head of the biceps tendon (LHBT) have been reported in the literature. Anatomic variations commonly explained are a third humeral head, anomalous insertion, congenital absence and adherence to the rotator cuff. We report a rare case who underwent shoulder arthroscopy with impingement symptoms where in LHBT was found to be bifurcated with a part attached to superior labrum and the other part to the posterior capsule of joint. Furthermore, intraarticular portion of LHBT was adherent to the undersurface of the supraspinatus tendon. Awareness of such an anatomical aberration during the shoulder arthroscopy is of great importance as it can potentially avoid unnecessary confusion and surgery. PMID:25143652

  4. Effects of prolonged patellar tendon vibration on force steadiness in quadriceps femoris during force-matching task.

    PubMed

    Saito, Akira; Ando, Ryosuke; Akima, Hiroshi

    2016-01-01

    The quadriceps femoris (QF) muscle group plays an essential role in human movement, such as standing, walking and running. The ability to maintain a steady force during physical activity of the human lower limb is important for mobility, postural control and balance. Although prolonged mechanical vibration of the muscle-tendon unit can moderate the efficacy of synaptic input from Ia afferent onto the α-motor neuron pathway, the effect of prolonged tendon vibration on fluctuations of knee extensor force has received little attention. The purpose of the present study was to examine the effects of prolonged patellar tendon vibration on the force steadiness of the QF muscle. Nine healthy men performed a submaximal force-matching task involving isometric knee extension before and after patellar tendon vibration or quiet seated rest (n = 7, control condition) for 30 min. The target force was 2.5, 10 and 30 % of maximal voluntary contraction (MVC). Surface electromyography (EMG) of the four QF synergists was recorded and normalized to EMG amplitude during the MVC. The knee extension force and the EMG amplitude of vastus medialis during the MVC were significantly reduced after the vibration, but did not significantly decrease in the control condition. Fluctuations of force and normalized EMG of individual QF muscles at each submaximal force level did not significantly change after the vibration. We conclude that prolonged patellar tendon vibration does not influence the force steadiness of the QF muscle during an isometric force-matching task.

  5. Profunda Femoris Pseudoaneurysm following Total Hip Arthroplasty Revision

    PubMed Central

    Harper, Katharine; Iorio, Justin; Balasubramanian, Easwaran

    2015-01-01

    Vascular injuries following total hip arthroplasty (THA) are very rare, with pseudoaneurysm being a small subset. We report a case of profunda femoris artery (PFA) pseudoaneurysm in a 61-year-old male following a posterior approach revision left THA. Presentation involved continued blood transfusion requirements several weeks postoperatively. Diagnosis of the pseduoaneurysm was made by contrast CT of the lower extremity, with confirmation via IR angiography. Successful embolization was achieved with selective coiling and Gelfoam. Presenting complaints of such complications are often vague and therefore lead to delayed diagnosis. Causes of such complications are not completely understood, particularly with PFA injuries in THA. Possible mechanisms are discussed in this paper. Vascular complications following THA can be difficult to diagnose. High suspicion in the setting of continued postoperative pain or bleeding may allow prompt diagnosis and avoidance of serious limb-threatening complications. PMID:26347839

  6. Intensity of activation and timing of deactivation modulate elastic energy storage and release in a pennate muscle and account for gait-specific initiation of limb protraction in the horse.

    PubMed

    Lichtwark, Glen A; Watson, Johanna C; Mavrommatis, Sophia; Wilson, Alan M

    2009-08-01

    The equine biceps brachii (biceps) initiates rapid limb protraction through a catapult mechanism. Elastic strain energy is slowly stored in an internal tendon and is then rapidly released to protract the forelimb. The muscle fibres are short, have little scope for length change and can therefore only shorten slowly compared with the speed at which the whole muscle must shorten, which makes them poor candidates for driving rapid limb protraction. We suggest that the muscle fibres in the biceps act to modulate the elastic energy output of the muscle-tendon unit (MTU) to meet the demands of locomotion under different conditions. We hypothesise that more elastic strain energy is stored and released from the biceps MTU during higher speed locomotion to accommodate the increase in energy required to protract the limb and that this can be achieved by varying the length change and activation conditions of the muscle. We examined the work performed by the biceps during trot and canter using an inverse dynamics analysis (IDA). We then used excised biceps muscles to determine how much work could be performed by the muscle in active and passive stretch-shorten cycles. A muscle model was developed to investigate the influence of changes in activation parameters on energy storage and energy return from the biceps MTU. Increased biceps MTU length change and increased work performed by the biceps MTU were found at canter compared with at trot. More work was performed by the ex vivo biceps MTU following activation of the muscle and by increasing muscle length change. However, the ratio of active to passive work diminished with increasing length change. The muscle model demonstrated that duration and timing of activation during stretch-shorten cycles could modulate the elastic energy storage and return from the biceps. We conclude that the equine biceps MTU acts as a tuneable spring and the contractile component functions to modulate the energy required for rapid forelimb

  7. The effect of knee brace on coordination and neuronal leg muscle control: an early postoperative functional study in anterior cruciate ligament reconstructed patients.

    PubMed

    Rebel, M; Paessler, H H

    2001-09-01

    Two studies were carried out after anterior cruciate ligament (ACL) reconstruction to determine the effect of a knee brace on coordination (test 1) and electromyographic muscle activity in drop jumps (test 2). Test 1 studied 25 patients with ACL reconstruction under three test conditions (one-leg static, two-legged static, two-legged dynamic) compared with a control (n=30). The results showed highly significant improvements in all braced conditions. In test 2 ten patients with ACL reconstruction and ten healthy subjects performed a two-legged drop-jump; this was repeated 15 times and again 15 times with a knee brace worn on the reconstructed limb. Changes in electromyographically determined muscle activity (vastus medialis, vastus lateralis, biceps femoris, gastrocnemius) were observed, but they were significant in only few cases because of high variability. Drop-jumps with knee brace improved jumping height, increased the maximum knee angle in the ground contact phase, and reduced the maximum knee angle in the landing phase. Patients thus develop an increased confidence in the stability of their knees. We conclude that the benefits of the knee brace are due to the mechanical action, an enhanced coordination, and a psychological effect.

  8. Developmental Stage, Muscle and Genetic Type Modify Muscle Transcriptome in Pigs: Effects on Gene Expression and Regulatory Factors Involved in Growth and Metabolism

    PubMed Central

    Ayuso, Miriam; Fernández, Almudena; Núñez, Yolanda; Benítez, Rita; Isabel, Beatriz; Fernández, Ana I.; Rey, Ana I.; González-Bulnes, Antonio; Medrano, Juan F.; Cánovas, Ángela; López-Bote, Clemente J.

    2016-01-01

    Iberian pig production includes purebred (IB) and Duroc-crossbred (IBxDU) pigs, which show important differences in growth, fattening and tissue composition. This experiment was conducted to investigate the effects of genetic type and muscle (Longissimus dorsi (LD) vs Biceps femoris (BF)) on gene expression and transcriptional regulation at two developmental stages. Nine IB and 10 IBxDU piglets were slaughtered at birth, and seven IB and 10 IBxDU at four months of age (growing period). Carcass traits and LD intramuscular fat (IMF) content were measured. Muscle transcriptome was analyzed on LD samples with RNA-Seq technology. Carcasses were smaller in IB than in IBxDU neonates (p < 0.001), while growing IB pigs showed greater IMF content (p < 0.05). Gene expression was affected (p < 0.01 and Fold change > 1.5) by the developmental stage (5,812 genes), muscle type (135 genes), and genetic type (261 genes at birth and 113 at growth). Newborns transcriptome reflected a highly proliferative developmental stage, while older pigs showed upregulation of catabolic and muscle functioning processes. Regarding the genetic type effect, IBxDU newborns showed enrichment of gene pathways involved in muscle growth, in agreement with the higher prenatal growth observed in these pigs. However, IB growing pigs showed enrichment of pathways involved in protein deposition and cellular growth, supporting the compensatory gain experienced by IB pigs during this period. Moreover, newborn and growing IB pigs showed more active glucose and lipid metabolism than IBxDU pigs. Moreover, LD muscle seems to have more active muscular and cell growth, while BF points towards lipid metabolism and fat deposition. Several regulators controlling transcriptome changes in both genotypes were identified across muscles and ages (SIM1, PVALB, MEFs, TCF7L2 or FOXO1), being strong candidate genes to drive expression and thus, phenotypic differences between IB and IBxDU pigs. Many of the identified regulators

  9. Developmental Stage, Muscle and Genetic Type Modify Muscle Transcriptome in Pigs: Effects on Gene Expression and Regulatory Factors Involved in Growth and Metabolism.

    PubMed

    Ayuso, Miriam; Fernández, Almudena; Núñez, Yolanda; Benítez, Rita; Isabel, Beatriz; Fernández, Ana I; Rey, Ana I; González-Bulnes, Antonio; Medrano, Juan F; Cánovas, Ángela; López-Bote, Clemente J; Óvilo, Cristina

    2016-01-01

    Iberian pig production includes purebred (IB) and Duroc-crossbred (IBxDU) pigs, which show important differences in growth, fattening and tissue composition. This experiment was conducted to investigate the effects of genetic type and muscle (Longissimus dorsi (LD) vs Biceps femoris (BF)) on gene expression and transcriptional regulation at two developmental stages. Nine IB and 10 IBxDU piglets were slaughtered at birth, and seven IB and 10 IBxDU at four months of age (growing period). Carcass traits and LD intramuscular fat (IMF) content were measured. Muscle transcriptome was analyzed on LD samples with RNA-Seq technology. Carcasses were smaller in IB than in IBxDU neonates (p < 0.001), while growing IB pigs showed greater IMF content (p < 0.05). Gene expression was affected (p < 0.01 and Fold change > 1.5) by the developmental stage (5,812 genes), muscle type (135 genes), and genetic type (261 genes at birth and 113 at growth). Newborns transcriptome reflected a highly proliferative developmental stage, while older pigs showed upregulation of catabolic and muscle functioning processes. Regarding the genetic type effect, IBxDU newborns showed enrichment of gene pathways involved in muscle growth, in agreement with the higher prenatal growth observed in these pigs. However, IB growing pigs showed enrichment of pathways involved in protein deposition and cellular growth, supporting the compensatory gain experienced by IB pigs during this period. Moreover, newborn and growing IB pigs showed more active glucose and lipid metabolism than IBxDU pigs. Moreover, LD muscle seems to have more active muscular and cell growth, while BF points towards lipid metabolism and fat deposition. Several regulators controlling transcriptome changes in both genotypes were identified across muscles and ages (SIM1, PVALB, MEFs, TCF7L2 or FOXO1), being strong candidate genes to drive expression and thus, phenotypic differences between IB and IBxDU pigs. Many of the identified regulators

  10. Simultaneous bilateral distal biceps tendon ruptures repaired using an endobutton technique: a case report

    PubMed Central

    2013-01-01

    Introduction The simultaneous rupture of both distal biceps tendons is a rare clinical entity that is difficult to treat and can have poor outcomes. A variety of treatment and rehabilitation options exist and have been reported for single sided and staged bilateral repairs, but none have described an approach for acute bilateral ruptures. Repairing distal biceps tendon ruptures using a single anterior incision and a cortical suspensory button technique has become increasingly popular in recent years. We present a report of our surgical approach using an endobutton technique and rehabilitation algorithm for this unusual injury pattern. Case presentation A 43-year-old Caucasian man presented with acute onset bilateral elbow pain while lifting a large sheet of drywall off the ground. He initially felt a ‘pop’ on the right and almost immediately felt another on the left after having to quickly shift the weight. He was unable to continue working and sought medical attention. His pain was predominantly in his bilateral antecubital fossae and he had significant swelling and ecchymoses. His clinical examination demonstrated no palpable tendon, a retracted biceps muscle belly, and clear supination weakness. Magnetic resonance imaging was performed and showed bilateral distal biceps tendon ruptures with retraction on both sides. After discussion with our patient, we decided that both sides would be repaired using a single anterior incision with endobutton fixation, first his right followed by his left six weeks later. Conclusion Overall, our patient did very well and had returned to full manual work by our last follow-up at 30 months. Although he was never able to return to competitive recreational hockey and was left with mild lateral antebrachial cutaneous nerve dysesthesias on his right, he felt he was at 85% of his premorbid level of function. We describe what we believe to be, to the best of our knowledge, the first case of simultaneous bilateral distal biceps

  11. The long head of biceps and associated tendinopathy.

    PubMed

    Ahrens, P M; Boileau, P

    2007-08-01

    This paper describes the current views on the pathology of lesions of the tendon of the long head of biceps and their management. Their diagnosis is described and their surgical management classified, with details of the techniques employed.

  12. Assessing voluntary muscle activation with the twitch interpolation technique.

    PubMed

    Shield, Anthony; Zhou, Shi

    2004-01-01

    stimuli. Sensitive twitch interpolation techniques have revealed small to moderate deficits in voluntary activation during brief maximal efforts and progressively increasing activation deficits (central fatigue) during exhausting exercise. A small number of recent studies suggest that resistance training may result in improved voluntary activation of the quadriceps femoris and ankle plantarflexor muscles but not the biceps brachii. A significantly larger body of evidence indicates that voluntary activation declines as a consequence of bed-rest, joint injury and joint degeneration. Twitch interpolation has also been employed to study the mechanisms by which caffeine and pseudoephedrine enhance exercise performance.

  13. Bovine sire selection based on maintenance energy affects muscle fiber type and meat color of F1 progeny.

    PubMed

    Thornton, K J; Welch, C M; Davis, L C; Doumit, M E; Hill, R A; Murdoch, G K

    2012-05-01

    A total of 42 F(1) Red Angus progeny from sires divergent in maintenance energy (ME(M)) EPD were analyzed to determine whether selecting for sire ME(M) would alter end-product meat quality. Data from animals were grouped based on the divergence of the ME(M) EPD of their sire from the Red Angus Association-reported breed average and defined as either high or low, the assumption being that high-ME(M) cattle are less efficient because their maintenance requirements represent a larger proportion of their dietary intake. Steer progeny (n = 7) from the high group produced bottom round steaks with a greater a* (redness) color value (P = 0.02) after 5 d in a simulated retail display when compared with bottom round steaks from the low group (n = 18). Bottom round steaks from the high group had a greater b* (yellowness) color value at d 1 (P = 0.03) and d 5 (P = 0.01) of retail display. Samples from the biceps femoris were taken at 12 mo (from both steers and heifers) and 15 mo (from steers only) of age for fiber type proportion analysis. At 12 mo of age, steers from the low group had more type I fibers (P = 0.02), whereas steers from the high group had more type IIb fibers (P = 0.01). Furthermore, samples from steers in the low group at 15 mo had more type I fibers (P = 0.02), and steers from the high group maintained more type IIb fibers (P = 0.02). No changes in fiber type proportions were observed between the high- and low-ME(M) EPD heifers (n = 17). Relative mRNA abundance of genes involved in the synthesis, storage, and breakdown of glycogen were analyzed as a variable important for meat quality, but no statistical differences were observed. At 12 mo age, glycogenin (glyc) was negatively correlated with the proportion of type IIa fibers (r = -0.32 and P = 0.12) as well as with the proportion of type IIb fibers (r = -0.42 and P = 0.03) in the biceps femoris of the steers. In samples taken from the biceps femoris at 15 mo age, glyc was negatively correlated with the

  14. Adaptive control for backward quadrupedal walking V. Mutable activation of bifunctional thigh muscles.

    PubMed

    Pratt, C A; Buford, J A; Smith, J L

    1996-02-01

    1. In this, the fifth article in a series to assess changes in posture, hindlimb dynamics, and muscle synergies associated with backward (BWD) quadrupedal walking, we compared the recruitment of three biarticular muscles of the cat's anterior thigh (anterior sartorius, SAa; medial sartorius, SAm; rectus femoris, RF) for forward (FWD) and BWD treadmill walking. Electromyography (EMG) records from these muscles, along with those of two muscles (semitendinosus, ST; anterior biceps femoris, ABF) studied previously in this series, were synchronized with kinematic data digitized from high-speed ciné film for unperturbed steps and steps in which a stumbling corrective reaction was elicited during swing. 2. During swing, the relative timing of EMG activity for the unifunctional SAm (hip and knee flexor) was similar for unperturbed steps of FWD and BWD walking. The SAm was active before paw lift off and remained active during most of swing (75%) for both forms of walking, but there was a marked decrease in EMG amplitude after paw off during BWD and not FWD swing. In contrast, the relative timing of EMG activity for the SAa and RF, two bifunctional muscles (hip flexors, knee extensors), was different for FWD and BWD swing. During FWD swing, the SAa and the RF (to a lesser extent) were coactive with the SAm; however, during BWD swing, the SAa and RF were active just before paw lift off and then inactive for the rest of swing until just before paw contact (see 3). Thus the swing-phase activity of the SAa and RF was markedly shorter for BWD than FWD swing. 3. Activity in SAa and RF was also different during FWD and BWD stance. The RF was consistently active from mid-to-late stance of FWD walking, and the SAa was also active during this period in some FWD steps. During the stance phase of BWD walking, however, the onset of activity in both muscles consistently shifted to early stance as both muscles became active just before paw contact (the E1 phase). Activity in RF

  15. Gauged M-flation after BICEP2

    NASA Astrophysics Data System (ADS)

    Ashoorioon, A.; Sheikh-Jabbari, M. M.

    2014-12-01

    In view of the recent BICEP2 results [arxiv:arXiv:1403.3985] which may be attributed to the observation of B-modes polarization of the CMB with tensor-to-scalar ratio r =0.2-0.05+0.07, we revisit M-flation model. Gauged M-flation is a string theory motivated inflation model with Matrix valued scalar inflaton fields in the adjoint representation of a U (N) Yang-Mills theory. In continuation of our previous works, we show that for a class of M-flation models the action for these inflaton fields can be such that the "effective inflaton field" ϕ has a double-well Higgs-like potential, with minima at ϕ = 0 , μ. We focus on the ϕ > μ, symmetry-breaking region. We thoroughly examine predictions of the model for r in the 2σ region allowed for nS by the Planck experiment. As computed in [arxiv:arXiv:0903.1481], for Ne = 60 and nS = 0.96 we find r ≃ 0.2, which sits in the sweet spot of BICEP2 region for r. We find that with increasing μ arbitrarily, nS cannot go beyond ≃0.9670, the scalar spectral index for the quadratic chaotic potential. As nS varies in the 2σ range which is allowed by Planck and could be reached by the model, r varies in the range [ 0.13 , 0.26 ]. Future cosmological experiments, like the CMBPOL, that confines nS with σ (nS) = 0.0029 can constrain the model further. Also, in this region of potential, for nS = 0.9603, we find that the largest isocurvature mode, which is uncorrelated with curvature perturbations, has a power spectrum with the amplitude of order 10-11 at the end of inflation. We also discuss the range of predictions of r in the hilltop region, ϕ < μ.

  16. Muscle Contraction Velocity: A Suitable Approach to Analyze the Functional Adaptations in Elite Soccer Players

    PubMed Central

    Loturco, Irineu; Pereira, Lucas A.; Kobal, Ronaldo; Kitamura, Katia; Ramírez-Campillo, Rodrigo; Zanetti, Vinicius; Abad, Cesar C. Cal; Nakamura, Fabio Y.

    2016-01-01

    Tensiomyography (TMG) has been used as a simple and non-invasive tool to assess the mechanical properties of skeletal muscles. The TMG-derived velocity of contraction (Vc), which can be calculated from the ratio between maximal radial displacement and the sum of contraction time and delay time, has been proposed for evaluating athletes. However, its sensitivity to training effects and possible relation with changes in soccer players’ neuromuscular performance have not yet been addressed. To test this possibility, twenty-two male Brazilian elite soccer players were assessed using TMG-derived Vc, unloaded squat jump, countermovement jump and drop jump at 45 cm, loaded jump squat and linear (20 m) and change of direction (COD) sprint tests, prior to and after an 8-week period, between two consecutive official tournaments, during which the concurrency between endurance and strength-power training commonly impairs neuromuscular capacities. Magnitude-based inference was used to detect meaningful training effects. From pre- to post-tests, it was observed likely to almost certainly improvements in all modes of jumping tests. In addition, we could verify decrements in the 20-m and COD sprint performances, which were rated as very likely and almost certainly, respectively. Finally, both rectus femoris and biceps femoris muscles presented a likely reduction in Vc. Therefore, chronic decreases in sprinting speed are possibly accompanied by a reduced TMG-derived Vc. From a practical standpoint, the TMG-derived Vc can be used to monitor negative specific-soccer training effects related to potential impairments in maximum speed. Key points Tensiomyography (TMG) can be considered a useful technology for coaches and sport scientists seeking for non-invasive and practical tools to assess the muscle function of elite athletes; Velocity of contraction (Vc) is a single index able to integrate several of the reliable mechanical outcomes provided by TMG, which was shown to be sensitive

  17. BICEP2, the curvature perturbation and supersymmetry

    SciTech Connect

    Lyth, David H.

    2014-11-01

    The tensor fraction r ≅ 0.16 found by BICEP2 corresponds to a Hubble parameter H ≅ 1.0 × 10{sup 14} GeV during inflation. This has two implications for the (single-field) slow-roll inflation hypothesis. First, the inflaton perturbation must account for much more than 10% of the curvature perturbation ζ, which barring fine-tuning means that it accounts for practically all of it. It follows that a curvaton-like mechanism for generating ζ requires an alternative to slow roll such as k-inflation. Second, accepting slow-roll inflation, the excursion of the inflaton field is at least of order Planck scale. As a result, the flatness of the inflaton presumably requires a shift symmetry. I point out that if such is the case, the resulting potential is likely to have at least approximately the quadratic form suggested in 1983 by Linde, which is known to be compatible with the observed r as well as the observed spectral index n{sub s}. The shift symmetry does not require supersymmetry. Also, the big H may rule out a GUT by restoring the symmetry and producing fatal cosmic strings. The absence of a GUT would correspond to the absence of superpartners for the Standard Model particles, which indeed have yet to be found at the LHC.

  18. No-holes transpectoral tenodesis technique vs tenotomy of the long head of the biceps brachii

    PubMed Central

    Gervasi, Enrico; Sebastiani, Enrico; Cautero, Enrico

    2016-01-01

    Summary Background There is no univocal consensus regarding Long Head of the Biceps (LHB) best treatment between tenotomy and tenodesis. There is no consensus regarding the best location to perform the tenodesis. The LHB tenodesis performed by the proximal tendon excision as first step can miss the proper tension to the muscle belly. Fixations proximal to the pectoralis major can lead to groove pain. This study aims to test the efficacy of a new LHB tenodesis technique by comparing its results with the tenotomy. Methods We retrospectively evaluated patients who underwent surgery between May 2014 and May 2015. The mean follow up was 14.7 months. Sixteen patients underwent mini-open tenodesis to the Pectoralis Major tendon by the use of a resorbable suture (TD group); sixteen underwent tenotomy (TT group). The mean age of the TD group was 54 years; the mean age of the TT group was 56 years. We evaluated pain, subjective perception of the patient of possible aesthetic and strength differences between the two biceps, “Popeye sign”, and tests to stimulate the LHB. We administered three evaluation questionnaires: the ASES score, the SPADI score, and the SST. Results 32 consecutive patients were evaluated. The clinical scores did not record statistically significant differences: the mean ASES score was 92.9 (TD) and 90.8 (TT); the mean SPADI score was 92.5 (TD), and 89.7 (TT); the mean SST was 8.9 (TD), and 8.4 (TT). Compared to the TD group, in the TT group we registered with greater frequency the “Popeye sign” with a P value < 0.05 (9 cases vs 1), and spasms in the biceps muscle belly (5 cases vs 1). All other signs or symptoms evaluated were more frequent in the TT group, except the strength difference perceived by the patient (3 patients in the TT group, and 2 in the TD group). No complications were recorded. Conclusions This new Long Head of the Biceps (LHB) tenodesis technique is valuable and reliable, and provided better results than tenotomy. Level of

  19. Fast muscle responses to an unexpected foot-in-hole scenario, evoked in the context of prior knowledge of the potential perturbation.

    PubMed

    Shinya, Masahiro; Masahiro, Shinya; Oda, Shingo; Shingo, Oda

    2010-06-01

    This study investigated the effect of prior knowledge of the potential loss of support during walking on muscle responses to the potential perturbation. Four conditions were tested; non-instructed control (NC), non-instructed perturbed (NP), instructed control (IC) and instructed perturbed (IP). Participants were perturbed by having them step into a hidden hole (8.5 cm) in a walkway during the NP and IP trials. Participants had no prior knowledge of the potential perturbation under the NC and NP conditions, but under the instructed conditions, participants were informed that there might be a hole in the walkway. A cautious landing strategy was observed in the IC trials. The participants exhibited flat-footed landings (plantar angle: NC: 13.7 +/- 2.8 degrees; IC: 8.5 +/- 5.2 degrees) and a prolonged double support phase (NC: 138 +/- 18 ms; IC: 161 +/- 17 ms) when they had prior knowledge of the possible hole. When the participants encountered a hole, we saw triggering of fast muscle responses in the ipsilateral plantarflexors and knee extensor, as well as in the contralateral dorsiflexors and knee flexors. This pattern was interpreted as a stop walking synergy. The opposite muscle activation pattern, which was thought of as a resume walking synergy, was induced when no hole was presented and actual foot contact occurred at the expected instant. The latencies between the onsets of muscle responses and the expected heel contact were shorter under the IP condition than under the NP condition (ipsilateral soleus: NP: 78 +/- 13 ms, IP: 64 +/- 14 ms; contralateral biceps femoris: NP: 94 +/- 25 ms; IP: 76 +/- 17 ms). Our results demonstrate that reactive muscle responses to perturbations depend on the anticipatory state with respect to potential perturbations.

  20. The comparison of wavelet- and Fourier-based electromyographic indices of back muscle fatigue during dynamic contractions: validity and reliability results.

    PubMed

    da Silva, R A; Larivière, C; Arsenault, A B; Nadeau, S; Plamondon, A

    2008-01-01

    The purpose of this study was to compare the electromyographic (EMG) fatigue indices computed from short-time Fourier transform (STFT) and wavelet transform (WAV), by analyzing their criterion validity and test-retest reliability. The effect of averaging spectral estimates within and between repeated contractions (cycles) on EMG fatigue indices was also demonstrated. Thirty-one healthy subjects performed trunk flexion-extension cycles until exhaustion on a Biodex dynamometer. The load was determined theoretically as twice the L5-S1 moment produced by the trunk mass. To assess reliability, 10 subjects performed the same experimental protocol after a two-week interval. EMG signals were recorded bilaterally with 12 pairs of electrodes placed on the back muscles (at L4, L3, L1 and T10 levels), as well as on the gluteus maximus and biceps femoris. The endurance time and perceived muscle fatigue (Borg CR-10 scale) were used as fatigue criteria. EMG signals were processed using STFT and WAV to extract global (e.g, median frequency and instantaneous median frequency, respectively) or local (e.g., intensity contained in 8 frequency bands) information from the power spectrum. The slope values of these variables over time, obtained from regression analyses, were retained as EMG fatigue indices. EMG fatigue indices (STFT vs. WAV) were not significantly different within each muscle, had a variable association (Pearson's r range.: 0.06 to 0.68) with our fatigue criteria, and showed comparable reliability (Intra-class correlation range: 0.00 to 0.88), although they varied between muscles. The effect of averaging, within and between cycles, contributed to the strong association between EMG fatigue indices computed from STFT and WAV. As for EMG spectral indices of muscle fatigue, the conclusion is that both transforms carry essentially the same information.

  1. Muscle strain injuries.

    PubMed

    Garrett, W E

    1996-01-01

    One of the most common injuries seen in the office of the practicing physician is the muscle strain. Until recently, little data were available on the basic science and clinical application of this basic science for the treatment and prevention of muscle strains. Studies in the last 10 years represent action taken on the direction of investigation into muscle strain injuries from the laboratory and clinical fronts. Findings from the laboratory indicate that certain muscles are susceptible to strain injury (muscles that cross multiple joints or have complex architecture). These muscles have a strain threshold for both passive and active injury. Strain injury is not the result of muscle contraction alone, rather, strains are the result of excessive stretch or stretch while the muscle is being activated. When the muscle tears, the damage is localized very near the muscle-tendon junction. After injury, the muscle is weaker and at risk for further injury. The force output of the muscle returns over the following days as the muscle undertakes a predictable progression toward tissue healing. Current imaging studies have been used clinically to document the site of injury to the muscle-tendon junction. The commonly injured muscles have been described and include the hamstring, the rectus femoris, gastrocnemius, and adductor longus muscles. Injuries inconsistent with involvement of a single muscle-tendon junction proved to be at tendinous origins rather than within the muscle belly. Important information has also been provided regarding injuries with poor prognosis, which are potentially repairable surgically, including injuries to the rectus femoris muscle, the hamstring origin, and the abdominal wall. Data important to the management of common muscle injuries have been published. The risks of reinjury have been documented. The early efficacy and potential for long-term risks of nonsteroidal antiinflammatory agents have been shown. New data can also be applied to the field

  2. Long head of the biceps pathology as a cause of anterior shoulder pain after shoulder arthroplasty.

    PubMed

    Tuckman, David V; Dines, David M

    2006-01-01

    The use of shoulder arthroplasty has been increasing over the last decade, with nearly 20,000 shoulder arthroplasties being performed each year. Although many patients have excellent results, there exists a subset of patients in whom anterior catching shoulder pain develops after arthroplasty. The purpose of this study was to examine this group of patients and explore treatment options and outcomes for this condition. We undertook a review of 8 shoulders in 7 patients who were treated for anterior shoulder pain radiating into the biceps muscle after shoulder arthroplasty. Three patients had a hemiarthroplasty for fracture, and five had a total shoulder arthroplasty. All patients had anterior shoulder pain with physical examination findings consistent with biceps tendon pathology. Definitive diagnosis and treatment consisted of either arthroscopy, in 7 of 8 shoulders, or an open procedure, in 1 of 8 shoulders. The range of motion improved in all shoulders. The hemiarthroplasty group showed an increase in flexion of 36 degrees (range, 68 degrees -104 degrees ), external rotation of 23 degrees (range, 11 degrees -34 degrees ), and internal rotation to L4. The total shoulder group demonstrated an increase in flexion of 50 degrees (range, 66 degrees -166 degrees ), external rotation of 27 degrees (range, 22 degrees -39 degrees ), and internal rotation to L3. The Hospital for Special Surgery score improved in all shoulders, with all patients being satisfied with their final outcome. Pain scores improved from a mean of 6.9 (range, 4-9) preoperatively to 1.4 (range, 0.5-2) postoperatively on a scale of 1 to 10, with 10 indicating the most pain. The role of the biceps tendon in the pathology of anterior shoulder pain after shoulder arthroplasty appears to be consistent with fibrosis and inflammation. Initial results, achieved with arthroscopic debridement or tenodesis, were encouraging.

  3. Effects of continuous white light and 12h white-12h blue light-cycles on the expression of clock genes in diencephalon, liver, and skeletal muscle in chicks.

    PubMed

    Honda, Kazuhisa; Kondo, Makoto; Hiramoto, Daichi; Saneyasu, Takaoki; Kamisoyama, Hiroshi

    2017-02-24

    The core circadian clock mechanism relies on a feedback loop comprised of clock genes, such as the brain and muscle Arnt-like 1 (Bmal1), chriptochrome 1 (Cry1), and period 3 (Per3). Exposure to the light-dark cycle synchronizes the master circadian clock in the brain, and which then synchronizes circadian clocks in peripheral tissues. Birds have long been used as a model for the investigation of circadian rhythm in human neurobiology. In the present study, we examined the effects of continuous light and the combination of white and blue light on the expression of clock genes (Bmal1, Cry1, and Per3) in the central and peripheral tissues in chicks. Seventy two day-old male chicks were weighed, allocated to three groups and maintained under three light schedules: 12h white light-12h dark-cycles group (control); 24h white light group (WW group); 12h white light-12h blue light-cycles group (WB group). The mRNA levels of clock genes in the diencephalon were significantly different between the control and WW groups. On the other hand, the alteration in the mRNA levels of clock genes was similar between the control and WB groups. Similar phenomena were observed in the liver and skeletal muscle (biceps femoris). These results suggest that 12h white-12h blue light-cycles did not disrupt the circadian rhythm of clock gene expression in chicks.

  4. Behaviour of the electrical impedance myography in isometric contraction of biceps brachii at different elbow joint angles

    NASA Astrophysics Data System (ADS)

    Coutinho, A. B. B.; Jotta, B.; Pino, A. V.; Souza, M. N.

    2012-12-01

    Electrical impedance myography (EIM) can be understood as an experimental technique applied to evaluate bioelectrical impedance associated to the muscular activity. With the development of technique, some studies are trying to associate the EIM parameters with the morphological and physiological changes that occur in the muscle during contraction. In this context this work sought to associate EIM parameters observed during isometric contractions of the biceps brachii muscle at different elbow joint angles with the correspondent muscular force. Differently from previous works that did not observe significant correlation between those data, our findings point to high correlations between the some EIM resistive parameters and the muscle force. Despite the need of further investigation, our results indicated that EIM technique can be used to estimate muscle force in a noninvasive way.

  5. Development of estimation system of knee extension strength using image features in ultrasound images of rectus femoris

    NASA Astrophysics Data System (ADS)

    Murakami, Hiroki; Watanabe, Tsuneo; Fukuoka, Daisuke; Terabayashi, Nobuo; Hara, Takeshi; Muramatsu, Chisako; Fujita, Hiroshi

    2016-04-01

    The word "Locomotive syndrome" has been proposed to describe the state of requiring care by musculoskeletal disorders and its high-risk condition. Reduction of the knee extension strength is cited as one of the risk factors, and the accurate measurement of the strength is needed for the evaluation. The measurement of knee extension strength using a dynamometer is one of the most direct and quantitative methods. This study aims to develop a system for measuring the knee extension strength using the ultrasound images of the rectus femoris muscles obtained with non-invasive ultrasonic diagnostic equipment. First, we extract the muscle area from the ultrasound images and determine the image features, such as the thickness of the muscle. We combine these features and physical features, such as the patient's height, and build a regression model of the knee extension strength from training data. We have developed a system for estimating the knee extension strength by applying the regression model to the features obtained from test data. Using the test data of 168 cases, correlation coefficient value between the measured values and estimated values was 0.82. This result suggests that this system can estimate knee extension strength with high accuracy.

  6. bicep2/KECK ARRAY. IV. OPTICAL CHARACTERIZATION AND PERFORMANCE OF THE bicep2 AND KECK ARRAY EXPERIMENTS

    SciTech Connect

    Ade, P. A. R.; Aikin, R. W.; Bock, J. J.; Brevik, J. A.; Filippini, J. P.; Golwala, S. R.; Hildebrandt, S. R.; Hui, H.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bradford, K. J.; Buder, I.; Bullock, E.; Dowell, C. D.; Duband, L.; Fliescher, S.; Halpern, M.; Hasselfield, M.; Hilton, G. C.; Collaboration: bicep2 and Keck Array Collaborations; and others

    2015-06-20

    bicep2 and the Keck Array are polarization-sensitive microwave telescopes that observe the cosmic microwave background (CMB) from the South Pole at degree angular scales in search of a signature of inflation imprinted as B-mode polarization in the CMB. bicep2 was deployed in late 2009, observed for three years until the end of 2012 at 150 GHz with 512 antenna-coupled transition edge sensor bolometers, and has reported a detection of B-mode polarization on degree angular scales. The Keck Array was first deployed in late 2010 and will observe through 2016 with five receivers at several frequencies (95, 150, and 220 GHz). bicep2 and the Keck Array share a common optical design and employ the field-proven bicep1 strategy of using small-aperture, cold, on-axis refractive optics, providing excellent control of systematics while maintaining a large field of view. This design allows for full characterization of far-field optical performance using microwave sources on the ground. Here we describe the optical design of both instruments and report a full characterization of the optical performance and beams of bicep2 and the Keck Array at 150 GHz.

  7. Biceps tendinitis in chronic rotator cuff tears: a histologic perspective.

    PubMed

    Singaraju, Vamsi M; Kang, Richard W; Yanke, Adam B; McNickle, Allison G; Lewis, Paul B; Wang, Vincent M; Williams, James M; Chubinskaya, Susan; Romeo, Anthony A; Cole, Brian J

    2008-01-01

    Patients with chronic rotator cuff tears frequently have anterior shoulder pain attributed to the long head of the biceps brachii (LHBB) tendon. In this study, tenodesis or tenotomy samples and cadaveric controls were assessed by use of immunohistochemical and histologic methods to quantify inflammation, vascularity, and neuronal plasticity. Patients had moderate pain and positive results on at least 1 clinical test of shoulder function. The number of axons in the distal LHBB was significantly less in patients with biceps tendinitis. Calcitonin gene-related peptide and substance P immunostaining was predominantly within nerve roots and blood vessels. A moderate correlation (R = 0.5) was identified between LHBB vascularity and pain scores. On the basis of these results, we conclude that, in the context of rotator cuff disease, the etiology of anterior shoulder pain with macroscopic changes in the biceps tendon is related to the complex interaction of the tendon and surrounding soft tissues, rather than a single entity.

  8. [Systematization of the musculo-tendinous architecture of the human biceps (musculus biceps brachii)].

    PubMed

    Farisse, J; Guidon, P; Seriat-Gautier, B; Brunet, C; Gambarelli, J

    1984-09-01

    The structure of the brachial biceps is studied based upon the bilateral dissections of six subjects. The object of this work consists of determining the distribution of the group and muscular fibers in relation to the two proximal insertions and the two distal insertions. It is possible to describe the subgroups within each structure. The objective of each of these subgroups is considered within the framework of the coordination between the two muscular formation and the double insertions on the structure of the forearm. It is probable that this muscular formation corresponds to two different movements of the forearm during the locomotory progression. This work can be utilised in the sphere of the comparative biomechanical observation. Also electromyographic and the histochemical characteristics of the muscular group.

  9. BICEP2. II. Experiment and three-year data set

    SciTech Connect

    Ade, P. A. R.; Aikin, R. W.; Bock, J. J.; Brevik, J. A.; Filippini, J. P.; Golwala, S. R.; Hildebrandt, S. R.; Amiri, M.; Davis, G.; Halpern, M.; Hasselfield, M.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Buder, I.; Bullock, E.; Day, P. K.; Dowell, C. D.; Duband, L.; Fliescher, S.; Collaboration: Bicep2 Collaboration; and others

    2014-09-01

    We report on the design and performance of the BICEP2 instrument and on its three-year data set. BICEP2 was designed to measure the polarization of the cosmic microwave background (CMB) on angular scales of 1°-5°(ℓ = 40-200), near the expected peak of the B-mode polarization signature of primordial gravitational waves from cosmic inflation. Measuring B-modes requires dramatic improvements in sensitivity combined with exquisite control of systematics. The BICEP2 telescope observed from the South Pole with a 26 cm aperture and cold, on-axis, refractive optics. BICEP2 also adopted a new detector design in which beam-defining slot antenna arrays couple to transition-edge sensor (TES) bolometers, all fabricated on a common substrate. The antenna-coupled TES detectors supported scalable fabrication and multiplexed readout that allowed BICEP2 to achieve a high detector count of 500 bolometers at 150 GHz, giving unprecedented sensitivity to B-modes at degree angular scales. After optimization of detector and readout parameters, BICEP2 achieved an instrument noise-equivalent temperature of 15.8 μK√s. The full data set reached Stokes Q and U map depths of 87.2 nK in square-degree pixels (5.'2 μK) over an effective area of 384 deg{sup 2} within a 1000 deg{sup 2} field. These are the deepest CMB polarization maps at degree angular scales to date. The power spectrum analysis presented in a companion paper has resulted in a significant detection of B-mode polarization at degree scales.

  10. Continuous Femoral Nerve Blocks: Decreasing Local Anesthetic Concentration to Minimize Quadriceps Femoris Weakness

    PubMed Central

    Bauer, Maria; Wang, Lu; Onibonoje, Olusegun K.; Parrett, Chad; Sessler, Daniel I.; Mounir-Soliman, Loran; Zaky, Sherif; Krebs, Viktor; Buller, Leonard T.; Donohue, Michael C.; Stevens-Lapsley, Jennifer E.; Ilfeld, Brian M.

    2012-01-01

    Background Whether decreasing the local anesthetic concentration during a continuous femoral nerve block results in less quadriceps weakness remains unknown. Methods Preoperatively, bilateral femoral perineural catheters were inserted in patients undergoing bilateral knee arthroplasty (n = 36) at a single clinical center. Postoperatively, right-sided catheters were randomly assigned to receive perineural ropivacaine of either 0.1% (basal 12 mL/h; bolus 4 mL) or 0.4% (basal 3 mL/h; bolus 1 mL), with the left catheter receiving the alternative concentration/rate in an observer- and subject-masked fashion. The primary endpoint was the maximum voluntary isometric contraction of the quadriceps femoris muscles the morning of postoperative day 2. Equivalence of treatments would be concluded if the 95% confidence interval for the difference fell within the interval of −20% to 20%. Secondary endpoints included active knee extension, passive knee flexion, tolerance to cutaneous electrical current applied over the distal quadriceps tendon, dynamic pain scores, opioid requirements, and ropivacaine consumption. Results Quadriceps maximum voluntary isometric contraction for limbs receiving 0.1% ropivacaine was a mean (SD) of 13 (8) N·m, versus 12 (8) N·m for limbs receiving 0.4% [intra-subject difference of 3 (40) percentage points; 95% CI −10 to 17; p = 0.63]. Because the 95% confidence interval fell within prespecified tolerances, we conclude that the effect of the two concentrations were equivalent. Similarly, there were no statistically significant differences in secondary endpoints. Conclusions For continuous femoral nerve blocks, we found no evidence that local anesthetic concentration and volume influence block characteristics, suggesting that local anesthetic dose (mass) is the primary determinant of perineural infusion effects. PMID:22293719

  11. Clinical anatomy and mechanical tensile properties of the rectus femoris tendon

    PubMed Central

    Zhu, Xing-Fei; Zhang, Xin-Chao

    2015-01-01

    Purpose: We aimed to provide anatomical data and mechanical tensile properties for the rectus femoris tendon to determine if it is a feasible substitute for the anterior cruciate ligament during knee joint reconstruction. Methods: The length and width of the quadriceps femoris tendon were measured from ten adult cadavers (20 knees; age =48±2 years). The anatomic features of the patellar insertion on the quadriceps femoris tendon were also documented. The rectus femoris tendon and anterior cruciate ligament were harvested from an additional five fresh specimens (10 knees; age =41±3 years). To minimize dehydration, each specimen was wrapped in saline-moistened paper towels and stored at -10°C. We imposed tensile stresses on a total of twenty samples in a sample-driven machine at 10 mm/min until the specimens failed. Results: The inserted and discrete widths of the rectus femoris tendon were 3.20±0.33 and 1.28±0.25 cm, respectively. The length of the tendon tissue was 6.96±0.80 cm and the length of mixing zone was 3.81±0.53 cm. The average thickness of the upper pole of the patella was 2.22±0.14 cm. In mechanical tensile properties, the unit modulus and unit maximum load of the rectus femoris tendon were both 63% of the anterior cruciate ligament. Conclusions: Based on its anatomical and mechanical tensile properties, the rectus femoris tendon is a feasible donor site to reconstitute the anterior cruciate ligament. PMID:26885205

  12. Dietary protein intake affects expression of genes for lipid metabolism in porcine skeletal muscle in a genotype-dependent manner.

    PubMed

    Liu, Yingying; Li, Fengna; He, Lingyun; Tan, Bie; Deng, Jinping; Kong, Xiangfeng; Li, Yinghui; Geng, Meimei; Yin, Yulong; Wu, Guoyao

    2015-04-14

    Skeletal muscle is a major site for the oxidation of fatty acids (FA) in mammals, including humans. Using a swine model, we tested the hypothesis that dietary protein intake regulates the expression of key genes for lipid metabolism in skeletal muscle. A total of ninety-six barrows (forty-eight pure-bred Bama mini-pigs (fatty genotype) and forty-eight Landrace pigs (lean genotype)) were fed from 5 weeks of age to market weight. Pigs of fatty or lean genotype were randomly assigned to one of two dietary treatments (low- or adequate-protein diet), with twenty-four individually fed pigs per treatment. Our data showed that dietary protein levels affected the expression of genes involved in the anabolism and catabolism of lipids in the longissimus dorsi and biceps femoris muscles in a genotype-dependent manner. Specifically, Bama mini-pigs had more intramuscular fat, SFA and MUFA, as well as elevated mRNA expression levels of lipogenic genes, compared with Landrace pigs. In contrast, Bama mini-pigs had lower mRNA expression levels of lipolytic genes than Landrace pigs fed an adequate-protein diet in the growing phase. These data are consistent with higher white-fat deposition in Bama mini-pigs than in Landrace pigs. In conclusion, adequate provision of dietary protein (amino acids) plays an important role in regulating the expression of key lipogenic genes, and the growth of white adipose tissue, in a genotype- and tissue-specific manner. These findings have important implications for developing novel dietary strategies in pig production.

  13. The effect of nutritional status on myogenic gene expression of satellite cells derived from different muscle types.

    PubMed

    Powell, D J; McFarland, D C; Cowieson, A J; Muir, W I; Velleman, S G

    2014-09-01

    Satellite cells (SC) are a multipotential stem cell population responsible for facilitating posthatch muscle fiber hypertrophy. The proliferation and differentiation of SC is sensitive to nutritional regimen, and the SC response to nutrition varies depending upon their muscle type of origin. The objective of the current study was to determine the effect of altering protein synthesis on the expression of several key genes regulating SC activity and the effect of muscle type. Satellite cells isolated from the fast glycolytic pectoralis major and the fast oxidative and glycolytic biceps femoris were studied. These genes included the myogenic regulatory factors myogenic determination factor 1 (MyoD) and myogenin, the cell-membrane associated proteoglycans syndecan-4 and glypican-1, the extracellular matrix proteoglycan decorin, and the transcription factor paired box 7. Protein synthesis potential varied by the concentration of the sulfur amino acids Met and Cys during SC proliferation and differentiation. The SC were cultured and treated with 1 of 6 Met/Cys concentrations: 60/192, 30/96 (control), 7.5/24, 3.0/9.6, 1.0/3.2, or 0/0 mg/L. A consistent pattern of gene expression emerged following Met/Cys manipulation as increasing reductions in mRNA expression for all genes were observed as Met/Cys concentration decreased, whereas increased Met/Cys concentration caused either no change or had a small negative effect on mRNA expression. Reduced paired box 7 expression would limit myogenic specification of SC, whereas decreased myogenic regulatory factor expression would affect subsequent myogenic development of the SC. Decreased levels of decorin affect SC response to growth factors like myostatin and transforming growth factor β, and extracellular matrix organization. These data highlight the importance of nutrition on the expression of genes critical for satellite cell activation, proliferation and differentiation, and growth factor signal transduction.

  14. Adaptive control for backward quadrupedal walking. II. Hindlimb muscle synergies.

    PubMed

    Buford, J A; Smith, J L

    1990-09-01

    stance was accompanied by a ramp increase in LG-EMG activity. At the knee joint, the yield was also small (or absent) for BWD walking, and increased VL-EMG amplitudes were associated with the increased range of knee extension for BWD stance. 5. Although the uniarticular hip extensor (anterior biceps femoris, ABF) was active during stance for both directions, the hip flexed during BWD stance and extended during FWD stance.(ABSTRACT TRUNCATED AT 400 WORDS)

  15. Effects of phosphatidic acid supplementation on muscle thickness and strength in resistance-trained men.

    PubMed

    Gonzalez, Adam M; Sell, Katie M; Ghigiarelli, Jamie J; Kelly, Christopher F; Shone, Edward W; Accetta, Matthew R; Baum, Jamie B; Mangine, Gerald T

    2017-04-01

    The purpose of this study was to investigate the effects of phosphatidic acid (PA) supplementation on muscle thickness and strength following an 8 week supervised resistance-training program. Fifteen resistance trained men (22.8 ± 3.5 years; 80.6 ± 8.7 kg; 178.1 ± 5.6 cm; 14.6% ± 8.8% body fat) were randomly assigned to a group that either consumed 750 mg of PA or a placebo (PL). Testing was carried out before (PRE) and after (POST) training/supplementation for muscle thickness and strength. Muscle thickness of the rectus femoris (RF), vastus lateralis (VL), biceps brachii (BB), and triceps brachii (TB) muscles were measured via ultrasonography, along with 1 repetition maximum (1RM) of squat, deadlift, and bench press. Analysis of covariance (ANCOVA), using PRE values as the covariate, did not reveal any group differences for measures of muscle thickness in the RF (PA: 3.6% ± 5.2%; PL: 3.2% ± 4.2%, p = 0.97), VL (PA: 23.4% ± 18.1%, PL: 12.5% ± 15.4%, p = 0.37), BB (PA: 3.7% ± 6.4%, PL: 9.6% ± 12.4%, p = 0.86), or TB (PA: 15.1% ± 17.9%, PL: 10.7% ± 19.3%, p = 0.79). Likewise, no group differences were observed in changes in squat (PA: 8.4% ± 4.1%, PL: 8.1% ± 4.2%, p = 0.79), deadlift (PA: 10.1% ± 10.1%, PL: 8.9% ± 9.5%, p = 0.66), or bench press (PA: 5.7% ± 5.5%, PL: 5.1% ± 3.0%, p = 0.76) exercises. Collectively, however, all participants experienced significant (p < 0.05) improvements in each measure of muscle thickness and strength. Results of this study suggest that PA supplementation, in combination with a 3 days·week(-1) resistance-training program for 8 weeks, did not have a differential effect compared with PL on changes in muscle thickness or 1RM strength.

  16. The effect of local skin cooling before a sustained, submaximal isometric contraction on fatigue and isometric quadriceps femoris performance: A randomized controlled trial.

    PubMed

    Hohenauer, Erich; Cescon, Corrado; Deliens, Tom; Clarys, Peter; Clijsen, Ron

    2017-04-01

    The central- and peripheral mechanisms by which heat strain limits physical performance are not fully elucidated. Nevertheless, pre-cooling is often used in an attempt to improve subsequent performance. This study compared the effects of pre-cooling vs. a pre-thermoneutral application on central- and peripheral fatigue during 60% of isometric maximum voluntary contraction (MVC) of the right quadriceps femoris muscle. Furthermore, the effects between a pre-cooling and a pre-thermoneutral application on isometric MVC of the right quadriceps femoris muscle and subjective ratings of perceived exertion (RPE) were investigated. In this randomized controlled trial, 18 healthy adults voluntarily participated. The participants received either a cold (experimental) application (+8°C) or a thermoneutral (control) application (+32°C) for 20min on their right thigh (one cuff). After the application, central (fractal dimension - FD) and peripheral (muscle fiber conduction velocity - CV) fatigue was estimated using sEMG parameters during 60% of isometric MVC. Surface EMG signals were detected from the vastus medialis and lateralis using bidimensional arrays. Immediately after the submaximal contraction, isometric MVC and RPE were assessed. Participants receiving the cold application were able to maintain a 60% isometric MVC significantly longer when compared to the thermoneutral group (mean time: 78 vs. 46s; p=0.04). The thermoneutral application had no significant impact on central fatigue (p>0.05) compared to the cold application (p=0.03). However, signs of peripheral fatigue were significantly higher in the cold group compared to the thermoneutral group (p=0.008). Pre-cooling had no effect on isometric MVC of the right quadriceps muscle and ratings of perceived exertion. Pre-cooling attenuated central fatigue and led to significantly longer submaximal contraction times compared to the pre-thermoneutral application. These findings support the use of pre-cooling procedures

  17. Rectus femoris transfer and musculo-skeletal modeling: effect of surgical treatment on gait and on rectus femoris kinematics.

    PubMed

    Desailly, Eric; Khouri, Nejib; Sardain, Philippe; Yepremian, Daniel; Lacouture, Patrick

    2011-10-01

    Spasticity of the rectus femoris (RF) is one of the possible causes of stiff knee gait (SKG) in cerebral palsy. Musculoskeletal studies have shown that in SKG, length and speed of the RF are affected. No evaluation had been made to quantify the modifications of those parameters after surgery. The effect of this operation on gait quality and on RF kinematics was assessed in this study in order to identify kinematic patterns that may aid its diagnosis. For 26 transfers, clinical gait analysis pre- and post-surgery was used to compute the Gait Deviation Index (GDI) and Goldberg's index. The kinematics of the Original RF path (ORFp) was studied before and after surgery. The expression ORFp was chosen to avoid any confusion between this modeling parameter, whose computation was unchanged, and the actual anatomical path that was modified by surgery. The gait quality was improved (+18±12GDI) and there was an inverse relation between the pre-operative GDI and its improvement. The Golberg's index was improved (88% of the cases). The operation had a significant effect on the normalization of the timings of maximum length and speed of the ORFp. The improvement of SKG was correlated with the normalization of the timing of the ORFp's maximum length. The global improvement of the gait quality and of the SKG was demonstrated. Some parameters of muscular kinematics (RF length and velocity) have been standardized, showing an effect of the transfer not only during the swing, but also during stance. The premature timing of the ORFp peak length has been identified as a prognostic factor of a successful surgical outcome.

  18. Partial rupture of the distal biceps brachii tendon in elite waterpolo goalkeeper: a case report of conservative treatment.

    PubMed

    Giombini, A; Innocenzi, L; Di Cesare, A; Di Salvo, W; Fagnani, F; Pigozzi, F

    2007-03-01

    The aim of this study was to describe a case of a 27-year-old male elite waterpolo goalkeeper, who had a partial rupture of the distal biceps tendon of his dominant arm while he was trying to save a strong outside shot. Pain on the antecubital fossa was the chief complaint. Ultrasound and magnetic resonance imaging completed the instrumental set-up. This case had the resolution of the pain and impairment after 3 months of conservative treatment. At 1-year follow-up, the athlete is asymptomatic and the isokinetic test provided almost complete recovery of the strength for elbow flexors and supinators muscles.

  19. Elbow tendinopathy and tendon ruptures: epicondylitis, biceps and triceps ruptures.

    PubMed

    Rineer, Craig A; Ruch, David S

    2009-03-01

    Lateral and medial epicondylitis are common causes of elbow pain in the general population, with the lateral variety being more common than the medial by a ratio reportedly ranging from 4:1 to 7:1. Initially thought to be an inflammatory condition, epicondylitis has ultimately been shown to result from tendinous microtearing followed by an incomplete reparative response. Numerous nonoperative and operative treatment options have been employed in the treatment of epicondylitis, without the emergence of a single, consistent, universally accepted treatment protocol. Tendon ruptures about the elbow are much less frequent, but result in more significant disability and loss of function. Distal biceps tendon ruptures typically occur in middle-aged males as a result of an event that causes a sudden, eccentric contraction of the biceps. Triceps tendon ruptures are exceedingly rare but usually have a similar etiology with a forceful eccentric contraction of the triceps that causes avulsion of the tendon from the olecranon. The diagnosis of these injuries is not always readily made. Complete ruptures of the biceps or triceps tendons have traditionally been treated surgically with good results. With regard to biceps ruptures, there continues to be debate about the best surgical approach, as well as the best method of fixation of tendon to bone. This article is not meant to be an exhaustive review of the broad topics of elbow tendinopathy and tendon ruptures, but rather is a review of recently published information on the topics that will assist the clinician in diagnosis and management of these conditions.

  20. Epimysium and Perimysium in Suturing in Skeletal Muscle Lacerations

    DTIC Science & Technology

    2005-07-01

    debridement or dissection as good ideas to locate con- nective tissues such as tendinous extensions within muscle to gain an optimal repair as opposed...Hand Surg [Am]. 1987;12:406–412. 4. Heckman JD, Levine MI. Traumatic closed transection of the biceps brachii in the military parachutist. J Bone Joint...Gakkai Zasshi. 1988; 62:415–425. 7. Kragh JF Jr, Basamania CJ. Surgical repair of acute traumatic closed transection of the biceps brachii. J Bone

  1. Tomographic elastography of contracting skeletal muscles from their natural vibrations

    NASA Astrophysics Data System (ADS)

    Sabra, Karim G.; Archer, Akibi

    2009-11-01

    Conventional elastography techniques require an external mechanical or radiation excitation to measure noninvasively the viscoelastic properties of skeletal muscles and thus monitor human motor functions. We developed instead a passive elastography technique using only an array of skin-mounted accelerometers to record the low-frequency vibrations of the biceps brachii muscle naturally generated during voluntary contractions and to determine their two-dimensional directionality. Cross-correlating these recordings provided travel-times measurements of these muscle vibrations between multiple sensor pairs. Travel-time tomographic inversions yielded spatial variations of their propagation velocity during isometric elbow flexions which indicated a nonuniform longitudinal stiffening of the biceps.

  2. The effect of different skin-ankle brace application pressures on quiet single-limb balance and electromyographic activation onset of lower limb muscles

    PubMed Central

    Papadopoulos, Emmanuel S; Nikolopoulos, Christos; Badekas, Athanasios; Vagenas, George; Papadakis, Stamatios A; Athanasopoulos, Spyros

    2007-01-01

    Background Several studies have been carried out in order to investigate the effect of ankle bracing on ankle joint function and performance. However, no study so far has examined the role of skin-brace interface pressure in neuromuscular control. The aim of this study was to investigate the effect of different skin-ankle brace interface pressures on quiet single limb balance and the electromyographic (EMG) activation sequence of four lower limb muscles. Methods Thirty three male physical education students who volunteered to take part in the study were measured under three ankle brace conditions: i) without brace, ii) with brace and 30 kPa application pressure and iii) with brace and 60 kPa application pressure. Single limb balance (anteroposterior and mediolateral parameter) was assessed on the dominant lower limb, with open and closed eyes, on a force platform, simultaneously with the EMG recording of four lower lower limb muscles' (gastrocnemius, peroneus longus, rectus femoris and biceps femoris) activation onset. Results The results showed that overall balance (total stability parameter) was not significantly affected in any of the three ankle brace conditions. However, the anteroposterior centre of pressure excursion and centre of pressure excursion velocity were significantly increased with the application of ankle brace, both with 30 and 60 kPa application pressures. Furthermore, it was found that single limb balance was significantly worse with closed eyes compared to open eyes. EMG measurements showed that the sequence of lower limb activation onset was not affected in any of the three ankle brace application conditions. The results of this study showed that the application of an ankle brace with two different skin-brace interface pressures had no effect on overall single limb balance and the sequence of lower limb muscle activation. Conclusion These findings suggest that peripheral joint receptors are either not adequately stimulated by the brace

  3. Acute calcific tendinitis of the rectus femoris associated with intraosseous involvement: a case report with serial CT and MRI findings.

    PubMed

    Kim, Young Sung; Lee, Ho Min; Kim, Jong Pil

    2013-11-01

    Acute calcific tendinitis of the shoulder is a well-known condition, but it is rare in the rectus femoris origin. Mostly reported cases were occurred in the reflected head of the rectus femoris, and only few cases were in the direct head of the rectus femoris. Intraosseous marrow involvement of calcific tendinitis is a more rare condition; it often goes misdiagnosed as an infection or a neoplasm. We report a rare, unusual case of acute calcific tendinitis of the direct head of the rectus femoris associated with intraosseous marrow involvement of calcification in anterior inferior iliac spine with serial CT and MRI findings. Aggressive osseous change may occur in acute calcific tendinitis of the rectus femoris as in this case which should be made an appropriate diagnosis to avoid unnecessary investigation and overtreatment like a surgery.

  4. Signaling Pathways Related to Protein Synthesis and Amino Acid Concentration in Pig Skeletal Muscles Depend on the Dietary Protein Level, Genotype and Developmental Stages.

    PubMed

    Liu, Yingying; Li, Fengna; Kong, Xiangfeng; Tan, Bie; Li, Yinghui; Duan, Yehui; Blachier, François; Hu, Chien-An A; Yin, Yulong

    2015-01-01

    Muscle growth is regulated by the homeostatic balance of the biosynthesis and degradation of muscle proteins. To elucidate the molecular interactions among diet, pig genotype, and physiological stage, we examined the effect of dietary protein concentration, pig genotype, and physiological stages on amino acid (AA) pools, protein deposition, and related signaling pathways in different types of skeletal muscles. The study used 48 Landrace pigs and 48 pure-bred Bama mini-pigs assigned to each of 2 dietary treatments: lower/GB (Chinese conventional diet)- or higher/NRC (National Research Council)-protein diet. Diets were fed from 5 weeks of age to respective market weights of each genotype. Samples of biceps femoris muscle (BFM, type I) and longissimus dorsi muscle (LDM, type II) were collected at nursery, growing, and finishing phases according to the physiological stage of each genotype, to determine the AA concentrations, mRNA levels for growth-related genes in muscles, and protein abundances of mechanistic target of rapamycin (mTOR) signaling pathway. Our data showed that the concentrations of most AAs in LDM and BFM of pigs increased (P<0.05) gradually with increasing age. Bama mini-pigs had generally higher (P<0.05) muscle concentrations of flavor-related AA, including Met, Phe, Tyr, Pro, and Ser, compared with Landrace pigs. The mRNA levels for myogenic determining factor, myogenin, myocyte-specific enhancer binding factor 2 A, and myostatin of Bama mini-pigs were higher (P<0.05) than those of Landrace pigs, while total and phosphorylated protein levels for protein kinase B, mTOR, and p70 ribosomal protein S6 kinases (p70S6K), and ratios of p-mTOR/mTOR, p-AKT/AKT, and p-p70S6K/p70S6K were lower (P<0.05). There was a significant pig genotype-dependent effect of dietary protein on the levels for mTOR and p70S6K. When compared with the higher protein-NRC diet, the lower protein-GB diet increased (P<0.05) the levels for mTOR and p70S6K in Bama mini-pigs, but

  5. Importance of correcting isokinetic peak torque for the effect of gravity when calculating knee flexor to extensor muscle ratios.

    PubMed

    Fillyaw, M; Bevins, T; Fernandez, L

    1986-01-01

    The purpose of our investigation was to compare, for the hamstring and quadriceps femoris muscles, peak torque values uncorrected for gravity with the peak torque values corrected for gravity and to determine the effect of making this correction on the hamstring to quadriceps femoris muscle peak torque ratio at slow and fast isokinetic speeds. We measured peak torques isokinetically at 60 degrees/sec (slow) and 240 degrees/sec (fast) in 25 female university soccer players. The gravity effect torque (GET) is the torque resulting from the effect of gravity on the combined weight of the leg and dynamometer arm at the precise angle of extension and flexion peak torque. The GET was added to the measured quadriceps femoris muscle peak torque and subtracted from the hamstring muscle peak torque to yield gravity corrected values. Failure to consider GET greatly underestimated quadriceps femoris muscle torque and overestimated hamstring muscle torque and the ratio between these torques at both speeds. Whereas the uncorrected hamstring to quadriceps femoris muscle peak torque ratio increased as speeds went from 60 degrees/sec to 240 degrees/sec, the gravity corrected ratio significantly decreased. Clinicians must remember the importance of making the gravity correction in patients with reduced torque output where the gravitational torque is a greater percentage of the measured torque to ascertain correctly the relative strength of antagonists inversely affected by gravity.

  6. Sporadic Inclusion Body Myositis Manifesting as Isolated Muscle Weakness of the Finger Flexors Three Years after Disease Onset

    PubMed Central

    Suwa, Yuichi; Suzuki, Naoki; Soga, Temma; Harada, Ryuhei; Shibui, Aya; Kuroda, Hiroshi; Izumi, Rumiko; Tateyama, Maki; Nakashima, Ichiro; Sonoo, Masahiro; Aoki, Masashi

    2016-01-01

    Sporadic inclusion body myositis (sIBM) is a chronic progressive myopathy characterized by muscle weakness of both the quadriceps femoris and finger flexors. We herein present the case of a typical male patient with sIBM, which manifested as the isolated weakness of the finger flexors three years after the disease onset. We have identified several patients with sIBM in our cohort with muscle weakness of the flexors but not the quadriceps femoris. Examination of the flexor digitorum profundus muscle is important for the early and proper diagnosis of sIBM, even if a patient only presents with isolated finger flexor muscle weakness. PMID:27904121

  7. Model-independent fit to Planck and BICEP2 data

    NASA Astrophysics Data System (ADS)

    Barranco, Laura; Boubekeur, Lotfi; Mena, Olga

    2014-09-01

    Inflation is the leading theory to describe elegantly the initial conditions that led to structure formation in our Universe. In this paper, we present a novel phenomenological fit to the Planck, WMAP polarization (WP) and the BICEP2 data sets using an alternative parametrization. Instead of starting from inflationary potentials and computing the inflationary observables, we use a phenomenological parametrization due to Mukhanov, describing inflation by an effective equation of state, in terms of the number of e-folds and two phenomenological parameters α and β. Within such a parametrization, which captures the different inflationary models in a model-independent way, the values of the scalar spectral index ns, its running and the tensor-to-scalar ratio r are predicted, given a set of parameters (α ,β). We perform a Markov Chain Monte Carlo analysis of these parameters, and we show that the combined analysis of Planck and WP data favors the Starobinsky and Higgs inflation scenarios. Assuming that the BICEP2 signal is not entirely due to foregrounds, the addition of this last data set prefers instead the ϕ2 chaotic models. The constraint we get from Planck and WP data alone on the derived tensor-to-scalar ratio is r <0.18 at 95% C.L., value which is consistent with the one quoted from the BICEP2 Collaboration analysis, r =0.16-0.05+0-06, after foreground subtraction. This is not necessarily at odds with the 2σ tension found between Planck and BICEP2 measurements when analyzing data in terms of the usual ns and r parameters, given that the parametrization used here, for the preferred value ns≃0.96, allows only for a restricted parameter space in the usual (ns,r) plane.

  8. Inflation after false vacuum decay: new evidence from BICEP2

    SciTech Connect

    Bousso, Raphael; Harlow, Daniel; Senatore, Leonardo E-mail: dharlow@princeton.edu

    2014-12-01

    Last year we argued that if slow-roll inflation followed the decay of a false vacuum in a large landscape, the steepening of the scalar potential between the inflationary plateau and the barrier generically leads to a potentially observable suppression of the scalar power spectrum at large distances. Here we revisit this analysis in light of the recent BICEP2 results. Assuming that both the BICEP2 B-mode signal and the Planck analysis of temperature fluctuations hold up, we find that the data now discriminate more sharply between our scenario and ΛCDM. Nonzero tensor modes exclude standard ΛCDM with notable but not yet conclusive confidence: at ∼3.8σ if r = 0.2, or at ∼ 3.5σ if r = 0.15. Of the two steepening models of our previous work, one is now ruled out by existing bounds on spatial curvature. The other entirely reconciles the tension between BICEP2 and Planck. Upcoming EE polarization measurements have the potential to rule out unmodified ΛCDM decisively. Next generation Large Scale Structure surveys can further increase the significance. More precise measurements of BB at low ℓ will help distinguish our scenario from other explanations. If steepening is confirmed, the prospects for detecting open curvature increase but need not be large.

  9. Inflation after false vacuum decay: new evidence from BICEP2

    NASA Astrophysics Data System (ADS)

    Bousso, Raphael; Harlow, Daniel; Senatore, Leonardo

    2014-12-01

    Last year we argued that if slow-roll inflation followed the decay of a false vacuum in a large landscape, the steepening of the scalar potential between the inflationary plateau and the barrier generically leads to a potentially observable suppression of the scalar power spectrum at large distances. Here we revisit this analysis in light of the recent BICEP2 results. Assuming that both the BICEP2 B-mode signal and the Planck analysis of temperature fluctuations hold up, we find that the data now discriminate more sharply between our scenario and ΛCDM. Nonzero tensor modes exclude standard ΛCDM with notable but not yet conclusive confidence: at ~3.8σ if r = 0.2, or at ~ 3.5σ if r = 0.15. Of the two steepening models of our previous work, one is now ruled out by existing bounds on spatial curvature. The other entirely reconciles the tension between BICEP2 and Planck. Upcoming EE polarization measurements have the potential to rule out unmodified ΛCDM decisively. Next generation Large Scale Structure surveys can further increase the significance. More precise measurements of BB at low l will help distinguish our scenario from other explanations. If steepening is confirmed, the prospects for detecting open curvature increase but need not be large.

  10. Chronic closed transection of the biceps brachii: a case report.

    PubMed

    Pandit, A; Wang, A; McKay, S; Ackland, T

    2011-08-01

    A 32-year-old man presented with chronic closed transection of the biceps brachii of the right arm after 30 months of conservative treatment. Magnetic resonance imaging showed atrophy of both long and short heads of the biceps brachii, with a 5-cm defect secondary to proximal and distal retraction on either side of the tear. There was a similar defect in the coracobrachialis, but the triceps brachii was normal. The self-rated overall arm status was 4 out of 10 (using a visual analogue scale). Objective functional deficit was measured using a dynamometer. Forearm flexion and supination strength of each arm at 120º/s was tested. The patient had a 34% deficit (40 vs. 61 Nm) in peak torque during forearm flexion and a 22% deficit (10 vs. 12 Nm) during forearm supination. The patient could not maintain maximal torque throughout the range of motion, with an approximately 50% deficit in the later part of the range of motion. The patient underwent reconstruction of the biceps brachii using an interposition Achilles tendon allograft.

  11. Long head of biceps: from anatomy to treatment.

    PubMed

    Sarmento, M

    2015-01-01

    The long head of the biceps (LHB), tendinous structure of the proximal brachial biceps, has its well-known anatomy, which contrasts with its current functional characterization. Various forms of proximal anchor and intra-articular route, important for the correct interpretation of its contribution to the pathology of the shoulder as well as the treatment methodology, are described. Knowledge of its biomechanics results mainly from cadaveric studies that contradict each other. Already the few studies in vivo indicate a depressant and stabilizing action, anterior, for the humeral head. Its pathology is rarely isolated because it is almost always correlated with rotator cuff or labrum pathology. It can be divided into 3 major groups (inflammatory, instability and traumatic) and subdivided according to its location. The anterior shoulder pain is the initial symptom of pathology of LHB Its perfect characterization is dependent on the associated injuries. Clinical tests are multiple and only their combination allows better sensitivity and specificity for LHB pathology. The arthro-MRI and dynamic ultrasound are able to increase proper diagnostic of the pathology of LHB. Treatment ranges from conservative and surgical. The latter includes the repair, tenotomy and tenodesis of LHB which can be performed by open or arthroscopic methodology. The author intends to review existing literature on all aspects related to the long head of the biceps from anatomy to treatment, presenting the latest results.

  12. Evidence for Bouncing Evolution Before Inflation After BICEP2

    NASA Astrophysics Data System (ADS)

    Xia, Jun-Qing; Cai, Yi-Fu; Li, Hong; Zhang, Xinmin

    2014-06-01

    The BICEP2 Collaboration reports a detection of primordial cosmic microwave background (CMB) B mode with a tensor-to-scalar ratio r =0.20-0.05+0.07 (68% C.L.). However, this result disagrees with the recent Planck limit r<0.11 (95% C.L.) on constraining inflation models. In this Letter we consider an inflationary cosmology with a preceding nonsingular bounce, which gives rise to observable signatures on primordial perturbations. One interesting phenomenon is that both the primordial scalar and tensor modes can have a step feature on their power spectra, which nicely cancels the tensor excess power on the CMB temperature power spectrum. By performing a global analysis, we obtain the 68% C.L. constraints on the parameters of the model from the Planck+WP and BICEP2 data together: the jump scale log10(kB/Mpc-1)=-2.4±0.2 and the spectrum amplitude ratio of bounce to inflation rB≡Pm/As=0.71±0.09. Our result reveals that the bounce inflation scenario can simultaneously explain the Planck and BICEP2 observations better than the standard cold dark matter model with a cosmological constant, and can be verified by future CMB polarization measurements.

  13. Differential Changes with Age in Multiscale Entropy of Electromyography Signals from Leg Muscles during Treadmill Walking.

    PubMed

    Kang, Hyun Gu; Dingwell, Jonathan B

    2016-01-01

    Age-related gait changes may be due to the loss of complexity in the neuromuscular system. This theory is disputed due to inconsistent results from single-scale analyses. Also, behavioral adaptations may confound these changes. We examined whether EMG dynamics during gait is less complex in older adults over a range of timescales using the multiscale entropy method, and whether slower walking attenuates this effect. Surface EMG was measured from the left vastus lateralis (VL), biceps femoris (BF), gastrocnemius (GA), and tibialis anterior (TA) in 17 young and 18 older adults as they walked on a treadmill for 5 minutes at 0.8x-1.2x of preferred speed. Sample entropy (SE) and the complexity index (CI) of the EMG signals were calculated after successive coarse-graining to extract dynamics at timescales of 27 to 270 Hz, with m = 2 and r = 0.15 SD. SE and CI were lower across the timescales in older adults in VL and BF, but higher in GA (all p<0.001); these results held for VL and GA even after accounting for longer EMG burst durations in older adults. CI was higher during slower walking speed in VL and BF (p<0.001). Results were mostly similar for m = 3 and r = 0.01-0.35. Smaller r was more sensitive to age-related differences. The decrease in complexity with aging in the timescales studied was limited to proximal muscles, particularly VL. The increase in GA may be driven by other factors. Walking slower may reflect a behavioral adaptation that allows the nervous system to function with greater complexity.

  14. Differential Changes with Age in Multiscale Entropy of Electromyography Signals from Leg Muscles during Treadmill Walking

    PubMed Central

    Kang, Hyun Gu; Dingwell, Jonathan B.

    2016-01-01

    Age-related gait changes may be due to the loss of complexity in the neuromuscular system. This theory is disputed due to inconsistent results from single-scale analyses. Also, behavioral adaptations may confound these changes. We examined whether EMG dynamics during gait is less complex in older adults over a range of timescales using the multiscale entropy method, and whether slower walking attenuates this effect. Surface EMG was measured from the left vastus lateralis (VL), biceps femoris (BF), gastrocnemius (GA), and tibialis anterior (TA) in 17 young and 18 older adults as they walked on a treadmill for 5 minutes at 0.8x-1.2x of preferred speed. Sample entropy (SE) and the complexity index (CI) of the EMG signals were calculated after successive coarse-graining to extract dynamics at timescales of 27 to 270 Hz, with m = 2 and r = 0.15 SD. SE and CI were lower across the timescales in older adults in VL and BF, but higher in GA (all p<0.001); these results held for VL and GA even after accounting for longer EMG burst durations in older adults. CI was higher during slower walking speed in VL and BF (p<0.001). Results were mostly similar for m = 3 and r = 0.01–0.35. Smaller r was more sensitive to age-related differences. The decrease in complexity with aging in the timescales studied was limited to proximal muscles, particularly VL. The increase in GA may be driven by other factors. Walking slower may reflect a behavioral adaptation that allows the nervous system to function with greater complexity. PMID:27570974

  15. Toxic heavy metals in the muscle of roe deer (Capreolus capreolus)--food toxicological significance.

    PubMed

    Lehel, József; Laczay, Péter; Gyurcsó, Adrienn; Jánoska, Ferenc; Majoros, Szilvia; Lányi, Katalin; Marosán, Miklós

    2016-03-01

    The study was performed on 20 (10 males, 10 females) roe deer (Capreolus capreolus) to investigate the concentration of cadmium, lead, mercury, and arsenic in the muscle tissue. They reside in forest and meadow, about 50 km distance from industrial activities and traffic. Samples were taken from the musculus biceps femoris of each deer without external contamination after shooting during the regular hunting season on a hunting area close to Eger in Hungary. The determination of heavy metal contents was carried out by inductively coupled plasma optical emission spectrometry (ICP-OES). The statistical analysis was performed by statistical package for the social sciences (SPSS) version 11.0. The measured residue concentration of cadmium was below the limit of detection in the roe deer meat indicating no health risk for the consumers. The average lead concentration (0.48 ± 0.21 mg/kg wet weight) exceeded the regulated maximum limit, but its calculated weekly intake was below the provisional tolerable weekly intake (PTWI). The residue level of mercury is not regulated and the average mercury content of roe deer meat (0.87 ± 0.40 mg/kg wet weight) was about half of PTWI, but the consumption of meat with the highest detected concentrations results in higher PTWI than recommended. The measured concentration of arsenic (0.27 ± 0.20 mg/kg wet weight) in the roe deer meat may not pose any health risk for the human consumers according to the PTWI set by the World Health Organization.

  16. BICEP2/SPUD: Searching for Inflation with Degree Scale Polarimetry from the South Pole

    NASA Technical Reports Server (NTRS)

    Nguyen, Hien Trong; Kovac, John; Adec, Peter; Aikin, Randol; Benton, Steve; Bock, Jamie; Brevik, Justus; Carlstrom, John; Dowell, Darren; Duband, Lionel; Golwala, Sunil; Halpern, Mark; Hasselfield, Matthew; Irwin, Kent; Jones, William; Kaufman, Jonathan; Keating, Brian; Kuo, Chao-Lin; Lange, Andrew; Matsumura, Tomotake; Netterfield, Barth; Pryke, Clem; Ruhl, John; Sheehy, Chris; Sudiwala, Rashmi

    2008-01-01

    BICEP2/SPUD is the new powerful upgrade of the existing BICEP1 experiment, a bolometric receiver to study the polarization of the cosmic microwave background radiation, which has been in operation at the South Pole since January 2006. BICEP2 will provide an improvement up to 10 times mapping speed at 150 GHz compared to BICEP1, using the same BICEP telescope mount. SPUD, a series of compact, mechanically-cooled receivers deployed on the DASI mount at the Pole, will provide similar mapping speed in to BICEP2 in three bands, 100, 150, and 220 GHz. The new system will use large TES focal plane arrays to provide unprecedented sensitivity and excellent control of foreground contamination.

  17. A Predictive Mathematical Model of Muscle Forces for Children with Cerebral Palsy

    ERIC Educational Resources Information Center

    Lee, Samuel C. K.; Ding, Jun; Prosser, Laura A.; Wexler, Anthony S.; Binder-Macleod, Stuart A.

    2009-01-01

    Aim: The purpose of this study was to determine if our previously developed muscle model could be used to predict forces of the quadriceps femoris and triceps surae muscles of children with spastic diplegic cerebral palsy (CP). Method: Twenty-two children with CP (12 males, 10 females; mean age 10y, SD 2y, range 7-13y; Gross Motor Function…

  18. Radiostereometric Evaluation of Tendon Elongation After Distal Biceps Repair

    PubMed Central

    Marshall, Nathan E.; Keller, Robert A.; Okoroha, Kelechi; Guest, John Michael; Yu, Charles; Muh, Stephanie; Moutzouros, Vasilios

    2016-01-01

    Background: Operative repair of distal biceps tendon ruptures has shown successful outcomes. However, little is known about the amount of tendon or repair site lengthening after repair. Purpose/Hypothesis: The purpose of this study was to evaluate distal biceps tendon repair via intratendinous radiostereometric analysis to analyze tendon lengthening at different time intervals of healing. The hypothesis was that there is significant lengthening after repair. Study Design: Case series; Level of evidence, 4. Methods: Eleven patients with distal biceps ruptures requiring operative repair were recruited. During repair, two 2-mm tantalum beads with laser-etched holes were sutured to the distal biceps tendon. Beads were evaluated via computed tomography scans immediately postoperatively and at 16 weeks. Radiographs were obtained at time 0 and then at 4, 8, and 16 weeks postoperatively. Measurements were made using the button-to-bead and bead-to-bead distances to assess repair site elongation as well as tendon elongation over time. After final follow-up, patients filled out the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and underwent ultrasound to confirm the integrity of the tendon. Results: Ten patients had complete ruptures, with 1 having a partial rupture that underwent completion of the tear and subsequent repair. All patients showed statistically significant lengthening after surgery. The mean amount of tendon lengthening after surgery was 22.8 mm (range, 11.2-30.9 mm; P < .05), and the repair site lengthened a mean 17.0 mm (range, 9.6-30.6 mm; P < .05) from surgery to final follow-up. The greatest change in lengthening was noted between time 0 and week 4 (mean, 11.3 mm; P < .05), with the least amount of lengthening between weeks 8 and 16 (mean, 2.6 mm; P < .05). The mean DASH score was 11.2. Final ultrasound evaluations found all tendons to be in continuity. Conclusion: All patients undergoing distal biceps tendon repair have significant

  19. Proximal versus Distal Nerve Transfer for Biceps Reinnervation—A Comparative Study in a Rat’s Brachial Plexus Injury Model

    PubMed Central

    McGrath, Aleksandra M.; Lu, Johnny Chuieng-Yi; Chang, Tommy Naj-Jen; Fang, Frank

    2016-01-01

    Background: The exact role of proximal and distal nerve transfers in reconstruction strategies of brachial plexus injury remains controversial. We compared proximal with distal nerve reconstruction strategies in a rat model of brachial plexus injury. Methods: In rats, the C6 spinal nerve with a nerve graft (proximal nerve transfer model, n = 30, group A) and 50% of ulnar nerve (distal nerve transfer model, n = 30, group B) were used as the donor nerves. The targets were the musculocutaneous nerve and the biceps muscle. Outcomes were recorded at 4, 8, 12, and 16 weeks postoperatively. Outcome parameters included grooming test, biceps muscle weight, compound muscle action potentials, tetanic contraction force, and axonal morphology of the donor and target nerves. Results: The axonal morphology of the 2 donor nerves revealed no significant difference. Time interval analysis in the proximal nerve transfer group showed peak axon counts at 12 weeks and a trend of improvement in all functional and physiologic parameters across all time points with statistically significant differences for grooming test, biceps compound action potentials, tetanic muscle contraction force, and muscle weight at 16 weeks. In contrast, in the distal nerve transfer group, the only statistically significant difference was observed between the 4 and 8 week time points, followed by a plateau from 8 to 16 weeks. Conclusions: Outcomes of proximal nerve transfers are ultimately superior to distal nerve transfers in our experimental model. Possible explanations for the superior results include a reduced need for cortical adaptation and higher proportions of motor units in the proximal nerve transfers. PMID:28293499

  20. Creatine Loading, Resistance Exercise Performance, and Muscle Mechanics.

    ERIC Educational Resources Information Center

    Stevenson, Scott W.; Dudley, Gary A.

    2001-01-01

    Examined whether creatine (CR) monohydrate loading would alter resistance exercise performance, isometric strength, or in vivo contractile properties of the quadriceps femoris muscle compared with placebo loading in resistance-trained athletes. Overall, CR loading did not provide an ergogenic benefit for the unilateral dynamic knee extension…

  1. Biceps tendon sheath effusion as a diagnostic clue to rotator cuff pathology.

    PubMed

    Yadav, Pankaj K; Shah, Bhavin; Shende, Amol; Rajesh, S

    2014-02-01

    The objective of this study was to evaluate the role of biceps tendon sheath effusion detected on ultrasound as a diagnostic clue to rotator cuff pathology. Despite being the most common cause of shoulder pain in adults early sonographic changes of rotator cuff tendinopathy are easy to miss. A total of 31 patients out of whom 27 had unilateral shoulder pain and 4 had bilateral complaints under- went ultrasonographic examination of shoulder joint using high frequency linear array transducer. Any fluid surrounding the long head of biceps tendon was noted followed by a careful search for any associated sonographic abnormality involving the rotator cuff. Eighteen out of the 35 had presence of fluid in their biceps tendon sheath. Twelve had presence of both biceps tendon sheath effusion and rotator cuff pathologies. Among 17 patients, who had no fluid in their biceps tendon sheath, only 2 had rotator cuff involvement whereas rest 15 had neither biceps tendon sheath fluid nor rotator cuff pathologies. A significant association was found between presence of fluid in long head of biceps tendon sheath and rotator cuff pathologies. Thus the most common finding observed in association with the presence of fluid around the long head of biceps tendon sheath in this study was tendinosis of rotator cuff. On ultrasonography simple presence of fluid around the long head of biceps tendon sheath demands careful examination of rotator cuff.

  2. Motor unit changes in thoracic paraspinal muscles in amyotrophic lateral sclerosis.

    PubMed

    de Carvalho, Mamede; Pinto, Susana; Swash, Michael

    2009-01-01

    In 38 amyotrophic lateral sclerosis (ALS) patients and 28 controls, we performed motor unit potential (MUP) analysis in the C-6 and T-5 paraspinal and biceps muscles. In ALS cases, we found similar abnormalities in MUPs in paraspinal and limb muscles. Fasciculation potentials (FPs) were more frequent in biceps than in paraspinal muscles, but fibrillation potentials and positive sharp waves (fibs-sw) were equally frequent in all three muscles. These results confirm the value of paraspinal MUP analysis in the diagnosis of ALS.

  3. Operator performance and localized muscle fatigue in a simulated space vehicle control task

    NASA Technical Reports Server (NTRS)

    Lewis, J. L., Jr.

    1979-01-01

    Fourier transforms in a special purpose computer were utilized to obtain power spectral density functions from electromyograms of the biceps brachii, triceps brachii, brachioradialis, flexor carpi ulnaris, brachialis, and pronator teres in eight subjects performing isometric tracking tasks in two directions utilizing a prototype spacecraft rotational hand controller. Analysis of these spectra in general purpose computers aided in defining muscles involved in performing the task, and yielded a derived measure potentially useful in predicting task termination. The triceps was the only muscle to show significant differences in all possible tests for simple effects in both tasks and, overall, was the most consistently involved of the six muscles. The total power monitored for triceps, biceps, and brachialis dropped to minimal levels across all subjects earlier than for other muscles. However, smaller variances existed for the biceps, brachioradialis, brachialis, and flexor carpi ulnaris muscles and could provide longer predictive times due to smaller standard deviations for a greater population range.

  4. Successful Treatment of Rectus Femoris Calcification with Ultrasound-guided Injection: A Case Report

    PubMed Central

    Hong, Myong Joo; Park, Jeong Ki; Kang, Tai Ug

    2015-01-01

    Painful periarticular calcification most commonly occurs within the rotator cuff of the shoulder and rarely around the elbow, hip, foot, and neck. As acute inflammatory reaction develops, severe pain, exquisite tenderness, local swelling, and limitation of motion with pain occur. In case of calcific tendinitis of the shoulder, it can be easily diagnosed according to the symptoms and with x-ray. However, in lesions of the hip, as it is a rare location and usually involves pain in the posterolateral aspect of the thigh, which can simulate radicular pain from a lumbar intervertebral disc, it could be difficult to diagnose. Hence, physicians usually focus on lumbar lesions; therefore, misdiagnosis is common and leads to a delayed management. Here, we report the case of a 30-year-old female patient with calcific tendinitis of the rectus femoris that was successfully managed with ultrasound-guided steroid injection. This study offers knowledge about the rectus femoris calcification. PMID:25589947

  5. Impairment of muscle force transmission in spastic-paretic muscles of stroke survivors.

    PubMed

    Xiaogang Hu; Afsharipour, Babak; Rymer, William Zev; Suresh, Nina L

    2016-08-01

    Hemispheric stroke survivors tend to have persistent motor impairments, with muscle weakness and muscle spasticity observed concurrently in the affected muscles. The objective of this preliminary study was to identify whether impairment of muscle force transmission could contribute to weakness in spastic-paretic muscles of chronic stroke survivors. To characterize the efficiency of the transmission of muscle forces to the tendon, we activated biceps brachii muscle electrically by stimulating the musculocutaneous nerve with maximum current. The ratio between the elicited maximum twitch force amplitude and the maximum M-wave peak-peak amplitude was calculated as a measure of the efficiency of force transmission. Based on the preliminary results of two stroke survivors, we show that the Force/M-wave ratio was reduced in the affected biceps brachii muscles in comparison with the contralateral muscles, indicating a potential impairment in the muscle force transmission in the affected muscles. Our findings suggest that disrupted muscle force transmission to the tendon could contribute to weakness in spastic muscles of chronic stroke survivors.

  6. Ruptured profunda femoris aneurysm secondary to neurofibromatosis: vascular involvement in an unusual location.

    PubMed

    Emrecan, Bilgin; Onem, Gokhan; Susam, Ibrahim

    2010-01-01

    Neurofibromatosis is an autosomal dominant genetic disease characterized by abnormal growth that involves tissues of mesodermal and neuroectodermal origin. Aneurysms are rarely seen in peripheral arteries. This report presents a case of ruptured arterial aneurysm secondary to neurofibromatosis; the lesion occurred in the profunda femoris artery, a highly unusual location. Treatment of patients with ruptured arterial aneurysm secondary to neurofibromatosis may be interventional or surgical. In this case, a surgical approach was successful.

  7. Dark matter chaotic inflation in light of BICEP2

    NASA Astrophysics Data System (ADS)

    Mukaida, Kyohei; Nakayama, Kazunori

    2014-08-01

    We propose an economical model in which a singlet 2-odd scalar field accounts for the primordial inflation and the present dark matter abundance simultaneously in the light of recent BICEP2 result. Interestingly, the reheating temperature and the thermal dark matter abundance are closely connected by the same interaction between the singlet scalar and the standard model Higgs. In addition, the reheating temperature turns out to be quite high, TR gtrsim 1012 GeV, and hence the thermal leptogenesis is compatible with this model. Therefore, it can be one of the simplest cosmological scenarios.

  8. The response of various muscle types to a restriction -re-alimentation feeding strategy in growing pigs.

    PubMed

    Lebret, B; Heyer, A; Gondret, F; Louveau, I

    2007-07-01

    Muscle lipid concentration is known to influence pork eating quality. This study aimed at evaluating the effect of a restriction-re-alimentation feeding strategy on intramuscular fat deposition in pigs. A total of 70 Duroc × (Large White × Landrace) pigs (castrated males and females) were used. Ten pigs were first slaughtered at 30 kg live weight (LW) to determine initial body and muscle composition. From 30 to 80 kg LW (growing period), pigs were either fed ad libitum (AL) or restricted to 70% of the ad libitum intake of AL pigs (RA). From 80 to 110 kg LW (finishing period), both AL and RA pigs were fed ad libitum. In each group, pigs were slaughtered at 80 kg (n = 10) and at 110 kg (n = 20) LW. During the growing period, the growth rate of RA pigs was reduced by 30% (P < 0.001) compared with AL pigs. During the finishing period, RA pigs had a 7% (P = 0.09) higher growth rate than AL pigs due to compensatory feed intake (+14%). Plasma insulin-like growth factor-1 concentration was lower in RA pigs at 80 kg LW, but markedly increased after re-alimentation up to the level observed in AL pigs (P < 0.001). At 80 kg, the leaner carcasses of RA pigs resulted from a more pronounced reduction in fat than in lean tissue deposition rates. Re-alimentation of RA pigs increased fat tissue deposition (+160% for females, P < 0.01) but not lean deposition in the carcass, leading to limited differences in carcass composition between RA and AL pigs at 110 kg LW. Regarding tissue deposition rates, the response to feeding strategy differs between muscles. In the m. biceps femoris (BF), restriction affected lipid (-50%, P < 0.001) and protein (-25%, P < 0.001) deposition, whereas re-alimentation increased lipid (+62%, P < 0.05) but not protein deposition rates. At market weight, the extent of the difference in BF lipid concentration between RA and AL pigs was strongly reduced, but still significant. By contrast, in the m. longissimus, restriction decreased protein but not lipid

  9. Structural changes in arm muscles after microgravity.

    PubMed

    Mayet-Sornay, M H; Hoppeler, H; Shenkman, B S; Desplanches, D

    2000-01-01

    Disuse muscle atrophy is a well-known consequence of spaceflight. However, most of the available muscle data concern lower limb muscles of rats and primates exposed to microgravity aboard Russian Cosmos biosatellites and American Space Shuttles. The purpose of our study was, therefore, to provide information concerning the effects of a 14-day spaceflight on two upper limb muscles of rhesus monkeys (Macaca mulatta). Our objective was to compare structural adaptations after 14 days of microgravity in a slow-twitch extensor muscle, i.e., the triceps, with a fast-twitch flexor muscle, i.e., the biceps. We hypothesize that muscle responses will be muscle specific, i.e., slow will differ from fast muscles, flexors will differ from extensors, and arms will differ from legs.

  10. Tendinopathy of the long head of the biceps tendon: histopathologic analysis of the extra-articular biceps tendon and tenosynovium

    PubMed Central

    Streit, Jonathan J; Shishani, Yousef; Rodgers, Mark; Gobezie, Reuben

    2015-01-01

    Background Bicipital tendinitis is a common cause of anterior shoulder pain, but there is no evidence that acute inflammation of the extra-articular long head of the biceps (LHB) tendon is the root cause of this condition. We evaluated the histologic findings of the extra-articular portion of the LHB tendon and synovial sheath in order to compare those findings to known histologic changes seen in other tendinopathies. Methods Twenty-six consecutive patients (mean age 45.4±13.7 years) underwent an open subpectoral biceps tenodesis for anterior shoulder pain localized to the bicipital groove. Excised tendons were sent for histologic analysis. Specimens were graded using a semiquantitative scoring system to evaluate tenocyte morphology, the presence of ground substance, collagen bundle characteristics, and vascular changes. Results Chronic inflammation was noted in only two of 26 specimens, and no specimen demonstrated acute inflammation. Tenocyte enlargement and proliferation, characterized by increased roundness and size of the cell and nucleus with proteoglycan matrix expansion and myxoid degenerative changes, was found in all 26 specimens. Abundant ground substance, collagen bundle changes, and increased vascularization were visualized in all samples. Conclusion Anterior shoulder pain attributed to the biceps tendon does not appear to be due to an inflammatory process in most cases. The histologic findings of the extra-articular portion of the LHB tendon and synovial sheath are similar to the pathologic findings in de Quervain tenosynovitis at the wrist, and may be due to a chronic degenerative process similar to this and other tendinopathies of the body. PMID:25792859

  11. [The role of the psoas muscle: apropos of the dissection of the muscles from 10 adults and 10 newborn infants].

    PubMed

    Le Floch-Prigent, P

    1983-06-01

    The action of the iliopsoas muscle (Musculus iliopsoas) on movements of the hip is studied by direct traction on fresh cadavers (10 still-born and 10 adults). The psoas muscle is a powerful flexor of the hip but also an external rotator. The action of external rotation is moderate but obvious in every position of the femur (Os femoris) and more important if previously in abduction and internal rotation.

  12. A method for detecting the temporal sequence of muscle activation during cycling using MRI.

    PubMed

    Elder, Christopher P; Cook, Ryan N; Wilkens, Kenneth L; Chance, Marti A; Sanchez, Otto A; Damon, Bruce M

    2011-03-01

    Surface electromyography (EMG) can assess muscle recruitment patterns during cycling, but has limited applicability to studies of deep muscle recruitment and electrically stimulated contractions. We determined whether muscle recruitment timing could be inferred from MRI-measured transverse relaxation time constant (T(2)) changes and a cycle ergometer modified to vary power as a function of pedal angle. Six subjects performed 6 min of single-leg cycling under two conditions (E0°-230° and E90°-230°), which increased the power from 0°-230° and 90-230° of the pedal cycle, respectively. The difference condition produced a virtual power output from 0-180° (V0°-180°). Recruitment was assessed by integrating EMG over the pedal cycle (IEMG) and as the (post-pre) exercise T(2) change (ΔT(2)). For E0°-230°, the mean IEMG for vastus medialis and lateralis (VM/VL; 49.3 ± 3.9 mV·s; mean ± SE) was greater (P < 0.05) than that for E90°-230° (17.9 ± 1.9 mV·s); the corresponding ΔT(2) values were 8.7 ± 1.0 and 1.4 ± 0.5 ms (P < 0.05). For E0°-230° and E90°-230°, the IEMG values for biceps femoris/long head (BF(L)) were 37.7 ± 5.4 and 27.1 ± 5.6 mV·s (P > 0.05); the corresponding ΔT(2) values were 0.9 ± 0.9 and 1.5 ± 0.9 ms (P > 0.05). MRI data indicated activation of the semitendinosus and BF/short head for E0°-230° and E90°-230°. For V0°-180°, ΔT(2) was 7.2 ± 0.9 ms for VM/VL and -0.6 ± 0.6 ms for BF(L); IEMG was 31.5 ± 3.7 mV·s for VM/VL and 10.6 ± 7.0 mV·s for BF(L). MRI and EMG data indicate VM/VL activity from 0 to 180° and selected hamstring activity from 90 to 230°. Combining ΔT(2) measurements with variable loading allows the spatial and temporal patterns of recruitment during cycling to be inferred from MRI data.

  13. Immediate Effect of Patterned Electrical Neuromuscular Stimulation on Pain and Muscle Activation in Individuals With Patellofemoral Pain

    PubMed Central

    Glaviano, Neal R.; Saliba, Susan A.

    2016-01-01

    Context:  For individuals with patellofemoral pain (PFP), altered muscle activity and pain are common during functional tasks. Clinicians often seek interventions to improve muscle activity and reduce impairments. One intervention that has not been examined in great detail is electrical stimulation. Objective:  To determine whether a single patterned electrical neuromuscular stimulation (PENS) treatment would alter muscle activity and pain in individuals with PFP during 2 functional tasks, a single-legged squat and a lateral step down. Design:  Cohort study. Setting:  Sports medicine research laboratory. Patients of Other Participants:  A total of 22 individuals with PFP (15 women, 7 men; age = 26.0 ± 7.9 years, height = 173.8 ± 8.1 cm, mass = 75.1 ± 17.9 kg). Intervention(s):  Participants were randomized into 2 intervention groups: a 15-minute PENS treatment that produced a strong motor response or a 15-minute 1-mA subsensory (sham) treatment. Main Outcome Measure(s):  Before and immediately after the intervention, we assessed normalized electromyography amplitude, percentage of activation time across functional tasks, and onset of activation for the vastus medialis oblique, vastus lateralis, gluteus medius, adductor longus, biceps femoris, and medial gastrocnemius muscles during a single-legged squat and a lateral step down. Scores on the visual analog scale for pain were recorded before and after the intervention. Results:  After a single treatment of PENS, the percentage of gluteus medius activation increased (0.024) during the lateral step down. Visual analog scores decreased during both the single-legged squat (PENS: preintervention = 2.7 ± 1.9, postintervention = 0.9 ± 0.7; sham: preintervention = 3.2 ± 1.6, postintervention = 2.8 ± 1.9; group × time interaction: P = .041) and lateral step down (PENS: preintervention = 3.4 ± 2.4, postintervention = 1.1 ± 0.8; sham: preintervention = 3.9 ± 1.7, postintervention = 3.3 ± 2.0; group

  14. Subpectoral biceps tenodesis for bicipital tendonitis with SLAP tear.

    PubMed

    Gupta, Anil K; Chalmers, Peter N; Klosterman, Emma L; Harris, Joshua D; Bach, Bernard R; Verma, Nikhil N; Cole, Brian J; Romeo, Anthony A

    2015-01-01

    The purpose of this study was to evaluate the outcomes of patients undergoing subpectoral biceps tenodesis for bicipital tendonitis with a superior labral anterior-posterior (SLAP) tear. Patients undergoing primary subpectoral biceps tenodesis for arthroscopically confirmed SLAP tears with signs or findings of bicipital tendonitis were included. An independent observer collected data prospectively as part of a data repository, which was then analyzed retrospectively. Primary outcome measures were the American Shoulder and Elbow Surgeons (ASES) score and pain relief via visual analog scale (VAS). Secondary outcome measures included the Simple Shoulder Test (SST), Constant, Single Assessment Numeric Evaluation (SANE), and Short Form 12 (SF-12) scores. Twenty-eight patients with a mean±SD age of 43.7±13.4 years and a mean±SD follow-up of 2.0±1.0 years met inclusion criteria. Workers' compensation was involved with 43% of cases, and 46% of the included patients were manual laborers. Eight (32%) patients were athletes, and 88% of the athletes were overhead athletes. Intraoperatively, 15 (54%) patients had type I SLAP tears, 10 (36%) had type II SLAP tears, 1 (3%) had a type III SLAP tear, and 2 (7%) had type IV SLAP tears. Significant improvements were seen in the following outcome measures pre- vs postoperatively: ASES score (58±23 vs 89±18; P=.001), SST score (6.3±3.6 vs 10.6±3.3; P=.001), SANE score (54±24 vs 88±25; P=.003), VAS score (3.8±2.0 vs 1.1±1.8; P=.001), SF-12 overall score (35±6 vs 42±6; P=.001), and SF-12 physical component score (39±6 vs 50±10; P=.001). Overall satisfaction was excellent in 80% of patients. Subpectoral biceps tenodesis demonstrates excellent clinical outcomes in select patients with SLAP tears. [Orthopedics. 2015; 38(1):e48-e53.].

  15. Body weight loss in beef cows: I. The effect of increased beta-oxidation on messenger ribonucleic acid levels of uncoupling proteins two and three and peroxisome proliferator-activated receptor in skeletal muscle.

    PubMed

    Brennan, K M; Michal, J J; Ramsey, J J; Johnson, K A

    2009-09-01

    Twenty-six Angus-cross cows were studied during BW loss (WL) and BW maintenance (WM) to examine the effects of elevated beta-oxidation on mRNA levels of NEFA-responsive signaling molecules in skeletal muscle. At the end of the WL and WM sampling periods, muscle biopsies were removed from the biceps femoris and mRNA levels were measured using real-time PCR. In comparison with WM, cows undergoing WL had elevated mRNA levels of carnitine palmitoyltransferase 1 (4.6-fold), fatty acid binding protein 3 (2.0-fold), and acyl-coenzyme A oxidase 1 (2.8-fold), all of which are indicators of beta-oxidation. Levels of mRNA of the NEFA-responsive signaling molecules PPAR alpha, delta, and gamma increased 2.0-fold, 2.2-fold, and 1.84-fold, respectively, during WL. Uncoupling proteins 2 and 3 also had increased mRNA (3.0-fold and 6.0-fold, respectively) during WL, but Western blot analysis found no changes in protein abundance of uncoupling protein 3. Uncoupling protein expression can be directly stimulated by elevated NEFA, potentially to protect cells from damage by lipid oxidation by-products. Thus, an increase in mRNA levels of genes involved in beta-oxidation of fatty acids and fatty acid by-products occurs during BW loss in beef cattle. These data support previous findings in nonruminants and suggest that these genes play a role in the same physiological processes in ruminants.

  16. bicep2/ KECK ARRAY . IV. OPTICAL CHARACTERIZATION AND PERFORMANCE OF THE bicep2 AND KECK ARRAY EXPERIMENTS

    SciTech Connect

    Ade, P. A. R.; Aikin, R. W.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Bradford, K. J.; Brevik, J. A.; Buder, I.; Bullock, E.; Dowell, C. D.; Duband, L.; Filippini, J. P.; Fliescher, S.; Golwala, S. R.; Halpern, M.; Hasselfield, M.; Hildebrandt, S. R.; Hilton, G. C.; Hui, H.; Irwin, K. D.; Kang, J. H.; Karkare, K. S.; Kaufman, J. P.; Keating, B. G.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Megerian, K. G.; Netterfield, C. B.; Nguyen, H. T.; O’Brient, R.; IV, R. W. Ogburn; Orlando, A.; Pryke, C.; Richter, S.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Sudiwala, R. V.; Teply, G. P.; Thompson, K.; Tolan, J. E.; Turner, A. D.; Vieregg, A. G.; Weber, A. C.; Wong, C. L.; Yoon, K. W.

    2015-06-18

    bicep2/KECK ARRAY. IV. OPTICAL CHARACTERIZATION AND PERFORMANCE OF THE bicep2 AND KECK ARRAY EXPERIMENTS P. A. R. Ade1, R. W. Aikin2, D. Barkats3, S. J. Benton4, C. A. Bischoff5, J. J. Bock2,6, K. J. Bradford5, J. A. Brevik2, I. Buder5, E. Bullock7Show full author list Published 2015 June 18 • © 2015. The American Astronomical Society. All rights reserved. The Astrophysical Journal, Volume 806, Number 2 Article PDF Figures Tables References Citations 273 Total downloads Cited by 6 articles Turn on MathJax Share this article Get permission to re-use this article Article information Abstract bicep2 and the Keck Array are polarization-sensitive microwave telescopes that observe the cosmic microwave background (CMB) from the South Pole at degree angular scales in search of a signature of inflation imprinted as B-mode polarization in the CMB. bicep2 was deployed in late 2009, observed for three years until the end of 2012 at 150 GHz with 512 antenna-coupled transition edge sensor bolometers, and has reported a detection of B-mode polarization on degree angular scales. The Keck Array was first deployed in late 2010 and will observe through 2016 with five receivers at several frequencies (95, 150, and 220 GHz). bicep2 and the Keck Array share a common optical design and employ the field-proven bicep1 strategy of using small-aperture, cold, on-axis refractive optics, providing excellent control of systematics while maintaining a large field of view. This design allows for full characterization of far-field optical performance using microwave sources on the ground. Here we describe the optical design of both instruments and report a full characterization of the optical performance and beams of bicep2 and the Keck Array at 150 GHz.

  17. Tendinopathy of the long head of the biceps.

    PubMed

    Snyder, Garrett M; Mair, Scott D; Lattermann, Christian

    2012-01-01

    Tendinopathy of the long head of the biceps is a common cause of anterior shoulder pain. As such, the anatomy and function of the tendon as well as its pathophysiology and different treatment methods have been studied extensively. The pathophysiology is a spectrum beginning with inflammation and leading to tendon degeneration. Different clinical tests and imaging modalities may all be employed to help aid in diagnosis. Conservative management is the first-line treatment, but surgical intervention may be warranted. In general, tenotomy or tenodesis is performed depending, among other things, on the age and activity level of the patient. There are several different methods for tenodesis, each with certain advantages and disadvantages. Patient factors must be considered when choosing the optimal treatment.

  18. Joint Analysis of BICEP2/Keck Array and Planck Data

    NASA Astrophysics Data System (ADS)

    BICEP2/Keck and Planck Collaborations; Ade, P. A. R.; Aghanim, N.; Ahmed, Z.; Aikin, R. W.; Alexander, K. D.; Arnaud, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barkats, D.; Barreiro, R. B.; Bartlett, J. G.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoît, A.; Benoit-Lévy, A.; Benton, S. J.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bischoff, C. A.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Boulanger, F.; Brevik, J. A.; Bucher, M.; Buder, I.; Bullock, E.; Burigana, C.; Butler, R. C.; Buza, V.; Calabrese, E.; Cardoso, J.-F.; Catalano, A.; Challinor, A.; Chary, R.-R.; Chiang, H. C.; Christensen, P. R.; Colombo, L. P. L.; Combet, C.; Connors, J.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; De Rosa, A.; de Zotti, G.; Delabrouille, J.; Delouis, J.-M.; Désert, F.-X.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Dowell, C. D.; Duband, L.; Ducout, A.; Dunkley, J.; Dupac, X.; Dvorkin, C.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Falgarone, E.; Filippini, J. P.; Finelli, F.; Fliescher, S.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Frejsel, A.; Galeotta, S.; Galli, S.; Ganga, K.; Ghosh, T.; Giard, M.; Gjerløw, E.; Golwala, S. R.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Halpern, M.; Hansen, F. K.; Hanson, D.; Harrison, D. L.; Hasselfield, M.; Helou, G.; Henrot-Versillé, S.; Herranz, D.; Hildebrandt, S. R.; Hilton, G. C.; Hivon, E.; Hobson, M.; Holmes, W. A.; Hovest, W.; Hristov, V. V.; Huffenberger, K. M.; Hui, H.; Hurier, G.; Irwin, K. D.; Jaffe, A. H.; Jaffe, T. R.; Jewell, J.; Jones, W. C.; Juvela, M.; Karakci, A.; Karkare, K. S.; Kaufman, J. P.; Keating, B. G.; Kefeli, S.; Keihänen, E.; Kernasovskiy, S. A.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Knox, L.; Kovac, J. M.; Krachmalnicoff, N.; Kunz, M.; Kuo, C. L.; Kurki-Suonio, H.; Lagache, G.; Lähteenmäki, A.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leitch, E. M.; Leonardi, R.; Levrier, F.; Lewis, A.; Liguori, M.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Lueker, M.; Macías-Pérez, J. F.; Maffei, B.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Mason, P.; Matarrese, S.; Megerian, K. G.; Meinhold, P. R.; Melchiorri, A.; Mendes, L.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Moss, A.; Munshi, D.; Murphy, J. A.; Naselsky, P.; Nati, F.; Natoli, P.; Netterfield, C. B.; Nguyen, H. T.; Nørgaard-Nielsen, H. U.; Noviello, F.; Novikov, D.; Novikov, I.; O'Brient, R.; Ogburn, R. W.; Orlando, A.; Pagano, L.; Pajot, F.; Paladini, R.; Paoletti, D.; Partridge, B.; Pasian, F.; Patanchon, G.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Pettorino, V.; Piacentini, F.; Piat, M.; Pietrobon, D.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Pratt, G. W.; Prunet, S.; Pryke, C.; Puget, J.-L.; Rachen, J. P.; Reach, W. T.; Rebolo, R.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Richter, S.; Ristorcelli, I.; Rocha, G.; Rossetti, M.; Roudier, G.; Rowan-Robinson, M.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Schwarz, R.; Scott, D.; Seiffert, M. D.; Sheehy, C. D.; Spencer, L. D.; Staniszewski, Z. K.; Stolyarov, V.; Sudiwala, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Teply, G. P.; Terenzi, L.; Thompson, K. L.; Toffolatti, L.; Tolan, J. E.; Tomasi, M.; Tristram, M.; Tucci, M.; Turner, A. D.; Valenziano, L.; Valiviita, J.; van Tent, B.; Vibert, L.; Vielva, P.; Vieregg, A. G.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Watson, R.; Weber, A. C.; Wehus, I. K.; White, M.; White, S. D. M.; Willmert, J.; Wong, C. L.; Yoon, K. W.; Yvon, D.; Zacchei, A.; Zonca, A.; Bicep2/Keck; Planck Collaborations

    2015-03-01

    We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400 deg2 patch of sky centered on RA 0 h, Dec. -57.5 ° . The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2 μ K deg in Q and U at 143 GHz). We detect 150 ×353 cross-correlation in B modes at high significance. We fit the single- and cross-frequency power spectra at frequencies ≥150 GHz to a lensed-Λ CDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes. We probe various model variations and extensions, including adding a synchrotron component in combination with lower frequency data, and find that these make little difference to the r constraint. Finally, we present an alternative analysis which is similar to a map-based cleaning of the dust contribution, and show that this gives similar constraints. The final result is expressed as a likelihood curve for r, and yields an upper limit r0.05<0.12 at 95% confidence. Marginalizing over dust and r, lensing B modes are detected at 7.0 σ significance.

  19. Joint analysis of BICEP2/keck array and Planck Data.

    PubMed

    Ade, P A R; Aghanim, N; Ahmed, Z; Aikin, R W; Alexander, K D; Arnaud, M; Aumont, J; Baccigalupi, C; Banday, A J; Barkats, D; Barreiro, R B; Bartlett, J G; Bartolo, N; Battaner, E; Benabed, K; Benoît, A; Benoit-Lévy, A; Benton, S J; Bernard, J-P; Bersanelli, M; Bielewicz, P; Bischoff, C A; Bock, J J; Bonaldi, A; Bonavera, L; Bond, J R; Borrill, J; Bouchet, F R; Boulanger, F; Brevik, J A; Bucher, M; Buder, I; Bullock, E; Burigana, C; Butler, R C; Buza, V; Calabrese, E; Cardoso, J-F; Catalano, A; Challinor, A; Chary, R-R; Chiang, H C; Christensen, P R; Colombo, L P L; Combet, C; Connors, J; Couchot, F; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Rosa, A; de Zotti, G; Delabrouille, J; Delouis, J-M; Désert, F-X; Dickinson, C; Diego, J M; Dole, H; Donzelli, S; Doré, O; Douspis, M; Dowell, C D; Duband, L; Ducout, A; Dunkley, J; Dupac, X; Dvorkin, C; Efstathiou, G; Elsner, F; Enßlin, T A; Eriksen, H K; Falgarone, E; Filippini, J P; Finelli, F; Fliescher, S; Forni, O; Frailis, M; Fraisse, A A; Franceschi, E; Frejsel, A; Galeotta, S; Galli, S; Ganga, K; Ghosh, T; Giard, M; Gjerløw, E; Golwala, S R; González-Nuevo, J; Górski, K M; Gratton, S; Gregorio, A; Gruppuso, A; Gudmundsson, J E; Halpern, M; Hansen, F K; Hanson, D; Harrison, D L; Hasselfield, M; Helou, G; Henrot-Versillé, S; Herranz, D; Hildebrandt, S R; Hilton, G C; Hivon, E; Hobson, M; Holmes, W A; Hovest, W; Hristov, V V; Huffenberger, K M; Hui, H; Hurier, G; Irwin, K D; Jaffe, A H; Jaffe, T R; Jewell, J; Jones, W C; Juvela, M; Karakci, A; Karkare, K S; Kaufman, J P; Keating, B G; Kefeli, S; Keihänen, E; Kernasovskiy, S A; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Knox, L; Kovac, J M; Krachmalnicoff, N; Kunz, M; Kuo, C L; Kurki-Suonio, H; Lagache, G; Lähteenmäki, A; Lamarre, J-M; Lasenby, A; Lattanzi, M; Lawrence, C R; Leitch, E M; Leonardi, R; Levrier, F; Lewis, A; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Lueker, M; Macías-Pérez, J F; Maffei, B; Maino, D; Mandolesi, N; Mangilli, A; Maris, M; Martin, P G; Martínez-González, E; Masi, S; Mason, P; Matarrese, S; Megerian, K G; Meinhold, P R; Melchiorri, A; Mendes, L; Mennella, A; Migliaccio, M; Mitra, S; Miville-Deschênes, M-A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Moss, A; Munshi, D; Murphy, J A; Naselsky, P; Nati, F; Natoli, P; Netterfield, C B; Nguyen, H T; Nørgaard-Nielsen, H U; Noviello, F; Novikov, D; Novikov, I; O'Brient, R; Ogburn, R W; Orlando, A; Pagano, L; Pajot, F; Paladini, R; Paoletti, D; Partridge, B; Pasian, F; Patanchon, G; Pearson, T J; Perdereau, O; Perotto, L; Pettorino, V; Piacentini, F; Piat, M; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polenta, G; Ponthieu, N; Pratt, G W; Prunet, S; Pryke, C; Puget, J-L; Rachen, J P; Reach, W T; Rebolo, R; Reinecke, M; Remazeilles, M; Renault, C; Renzi, A; Richter, S; Ristorcelli, I; Rocha, G; Rossetti, M; Roudier, G; Rowan-Robinson, M; Rubiño-Martín, J A; Rusholme, B; Sandri, M; Santos, D; Savelainen, M; Savini, G; Schwarz, R; Scott, D; Seiffert, M D; Sheehy, C D; Spencer, L D; Staniszewski, Z K; Stolyarov, V; Sudiwala, R; Sunyaev, R; Sutton, D; Suur-Uski, A-S; Sygnet, J-F; Tauber, J A; Teply, G P; Terenzi, L; Thompson, K L; Toffolatti, L; Tolan, J E; Tomasi, M; Tristram, M; Tucci, M; Turner, A D; Valenziano, L; Valiviita, J; Van Tent, B; Vibert, L; Vielva, P; Vieregg, A G; Villa, F; Wade, L A; Wandelt, B D; Watson, R; Weber, A C; Wehus, I K; White, M; White, S D M; Willmert, J; Wong, C L; Yoon, K W; Yvon, D; Zacchei, A; Zonca, A

    2015-03-13

    We report the results of a joint analysis of data from BICEP2/Keck Array and Planck. BICEP2 and Keck Array have observed the same approximately 400  deg^{2} patch of sky centered on RA 0 h, Dec. -57.5°. The combined maps reach a depth of 57 nK deg in Stokes Q and U in a band centered at 150 GHz. Planck has observed the full sky in polarization at seven frequencies from 30 to 353 GHz, but much less deeply in any given region (1.2  μK deg in Q and U at 143 GHz). We detect 150×353 cross-correlation in B modes at high significance. We fit the single- and cross-frequency power spectra at frequencies ≥150  GHz to a lensed-ΛCDM model that includes dust and a possible contribution from inflationary gravitational waves (as parametrized by the tensor-to-scalar ratio r), using a prior on the frequency spectral behavior of polarized dust emission from previous Planck analysis of other regions of the sky. We find strong evidence for dust and no statistically significant evidence for tensor modes. We probe various model variations and extensions, including adding a synchrotron component in combination with lower frequency data, and find that these make little difference to the r constraint. Finally, we present an alternative analysis which is similar to a map-based cleaning of the dust contribution, and show that this gives similar constraints. The final result is expressed as a likelihood curve for r, and yields an upper limit r_{0.05}<0.12 at 95% confidence. Marginalizing over dust and r, lensing B modes are detected at 7.0σ significance.

  20. Weighing Neutrinos in f(R) Gravity in Light of BICEP2

    NASA Astrophysics Data System (ADS)

    Zhou, Xiao-Ying; He, Jian-Hua

    2014-07-01

    We constrain the neutrino mass in f(R) gravity using the latest observations from the Planck, BAO and BICEP2 data. We find that the measurement on the B-modes can break the degeneracy between the massive neutrinos and the f(R) gravity. We find a non-zero value of the Compton wavelengths B0 at a 68% confidence level for the f(R) model in the presence of massive neutrinos when the BICEP2 data is used. Furthermore, the tension on the tensor-to-scalar ratios between the measured values from Plank and BICEP2 is significantly reconciled in our model.

  1. Reconstruction of posterior interosseous nerve injury following biceps tendon repair: case report and cadaveric study.

    PubMed

    Mokhtee, David B; Brown, Justin M; Mackinnon, Susan E; Tung, Thomas H

    2009-06-01

    Surgical repair of distal biceps tendon rupture is a technically challenging procedure that has the potential for devastating and permanently disabling complications. We report two cases of posterior interosseous nerve (PIN) injury following successful biceps tendon repair utilizing both the single-incision and two-incision approaches. We also describe our technique of posterior interosseous nerve repair using a medial antebrachial cutaneous nerve graft (MABC) and a new approach to the terminal branches of the posterior interosseous nerve that makes this reconstruction possible. Finally, we advocate consideration for identification of the posterior interosseous nerve prior to reattachment of the biceps tendon to the radial tuberosity.

  2. Detection of degree-scale B-mode polarization and studying cosmic polarization rotation with the BICEP1 and BICEP2 telescopes

    NASA Astrophysics Data System (ADS)

    Kaufman, Jonathan Philip

    The BICEP1 and BICEP2 telescopes studied the temperature and polarization of the Cosmic Microwave Background (CMB) from 2006 -- 2008 and 2010 -- 2012, respectively, producing the deepest maps of polarization created to date. From BICEP2 three-year data, we detect B-mode polarization at the degree-scale above the expectation from lensed-ΛCDM to greater than 5sigma significance, consistent with that expected from gravitational waves created during Inflation. Instrumental systematic effects have been characterized and ruled out, and galactic foreground contamination is disfavored by the data. Additionally, correlations between temperature and B-mode polarization and between E-mode and B-mode polarization show evidence of polarization rotation of --1° to 5sigma significance; however, adding systematic uncertainty reduces this significance to ˜ 2sigma. These measurements, combined with other CMB and astrophysical measurements, point to possible parity violating physics like cosmic birefringence, but more precise calibration techniques are required to break the degeneracy between cosmic polarization rotation and systematic effects. Improved calibration is possible with current generation technology and may be achieved within the next few years. In this work, I present experimental and analysis techniques employed for BICEP1 and BICEP2 to measure B-mode polarization and temperature and polarization correlations, as well as the scientific motivation, results, and a path forward for future measurements.

  3. Voluntary activation failure is detectable in some myositis patients with persisting quadriceps femoris weakness: an observational study

    PubMed Central

    Molloy, Catherine B; Al-Omar, Ahmed O; Edge, Kathryn T; Cooper, Robert G

    2006-01-01

    This cross-sectional, observational study was undertaken to examine whether voluntary activation failure could contribute to the persisting weakness observed in some patients with treated idiopathic inflammatory myositis. In 20 patients with myositis of more than six months' duration (5 males, 15 females; mean [± 1 SD] age 53 [11] years) and 102 normal subjects (44 males, 58 females; mean age 32 [8] years), isometric maximum voluntary contractions (MVCs) of the dominant quadriceps femoris (QF) were quantified. Absolute MVC results of normal subjects and patients were then normalised with respect to lean body mass (force per units of lean body mass), giving a result in Newtons per kilogram. Based on mass-normalised force data of normal subjects, patients were arbitrarily stratified into "weak" and "not weak" subgroups. During further MVC attempts, the "twitch interpolation" technique was used to assess whether the QF voluntary activation of patients was complete. This technique relies on the fact that, because muscle activation is incomplete during submaximal voluntary contractions, electrical stimulation of the muscle can induce force increments superimposed on the submaximal voluntary force being generated. No between-gender differences were seen in the mass-normalised MVC results of healthy subjects, so the gender-combined results of 6.6 (1.5) N/kg were used for patient stratification. No between-gender difference was found for mass-normalised MVCs in patients: males 5.4 (3.2) and females 3.0 (1.7) N/kg (p > 0.05). Mass-normalised MVCs of male patients were as great as those of normal subjects (p > 0.05), but mass-normalised MVCs of female patients were significantly smaller than those of the normal subjects (p < 0.001). Only one of the six "not weak" patients exhibited interpolated twitches during electrical stimulation, but six of the 14 "weak" patients did, the biggest twitches being seen in the weakest patient. That interpolated twitches can be induced in

  4. New insight of some extracellular matrix molecules in beef muscles. Relationships with sensory qualities.

    PubMed

    Dubost, A; Micol, D; Lethias, C; Listrat, A

    2016-05-01

    The aim of this study was to highlight the relationships between decorin, tenascin-X and type XIV collagen, three minor molecules of extracellular matrix (ECM), with some structural parameters of connective tissue and its content in total collagen, its cross-links (CLs) and its proteoglycans (PGs). In addition, we have evaluated impact of these minor molecules on beef quality traits. The relative abundance of these molecules was evaluated by western blot analysis in Longissimus thoracis (LT) and Biceps femoris (BF) muscles from Aberdeen Angus and Blond d'Aquitaine beef breeds. Decorin and tenascin-X were more abundant in BF than in LT (1.8 v. 0.5 arbitrary units (AU), respectively, P<0.001, and 1.0 v. 0.6 AU, P<0.05). There was no muscle effect for collagen XIV content. Decorin and tenascin-X relative abundance were positively correlated with perimysium and endomysium areas and with collagen characteristics (total, insoluble and CLs). Decorin was negatively correlated with total PG content and positively with tenascin-X. Collagen XIV was correlated with any of parameters measured. To assess the impact of decorin, tenascin-X and collagen XIV and of their ratios to total collagen and PGs on shear force and quality traits we realized, respectively, a multiple-linear regression analysis and a Pearson's correlation analysis. Decorin and tenascin-X relative abundance were, respectively, negatively and positively involved in juiciness. Decorin relative abundance was also negatively involved in abnormal flavour and positively in overall liking. The ratio of decorin to total collagen and PGs was negatively correlated to juiciness, together with collagen XIV ratio to total PGs. The ratios of decorin, tenascin-X and collagen XIV to total PGs were positively correlated to sensory tenderness, negatively to abnormal beef flavour and positively to overall liking. The ratio of decorin to total collagen was also negatively correlated to abnormal flavour and positively to overall

  5. Effects of unilateral and bilateral lower-body heavy resistance exercise on muscle activity and testosterone responses.

    PubMed

    Jones, Margaret T; Ambegaonkar, Jatin P; Nindl, Bradley C; Smith, Jeffrey A; Headley, Samuel A

    2012-04-01

    Unilateral and bilateral lower-body heavy resistance exercises (HREs) are used for strength training. Little research has examined whether muscle activation and testosterone (TES) responses differ between these exercises. Our purpose was to compare the effects of unilateral and bilateral lower-body HRE on muscle activity using surface electromyography (sEMG) and TES concentrations. Ten resistance-trained, college-aged male athletes (football, track and field) completed 5 testing sessions in which bilateral (back squat [BS]) and unilateral (pitcher squat [PS]) exercises were performed using a counterbalanced design. Sessions 1 and 2 determined estimated maximum strength (10 repetition maximum [10RM]) in the BS and PS. During testing session 3, muscle activation (sEMG) was measured in the right vastus lateralis, biceps femoris, gluteus maximus, and erector spinae (ES) during both BS and PS (stance leg) exercises. In sessions 4 and 5, total TES concentrations (nanomoles per liter) were measured via blood draws at baseline (preexercise), 0, 5, 10, 15, and 30 minutes postexercise after 4 sets of 10 repetitions at the 10RM. Separate repeated-measures analyses of variance examined differences in sEMG and TES between BS and PS (p < 0.05). The sEMG amplitudes were similar (p = 0.80) for BS (0.22 ± 0.06 mV) and PS (0.20 ± 0.07 mV). The TES responses were also similar (p = 0.15) between BS (21.8 ± 6.9 nmol·L(-1)) and PS (26.2 ± 10.1 nmol·L(-1)). The similar lower limb and back sEMG and TES responses may indicate that the neuromuscular and hormonal demands were comparable for both the BS and PS exercises despite the absolute work being less in the PS. The PS exercise may be an effective method for including unilateral exercise into lower-body resistance training when designing training programs for ground-based activities.

  6. The Painful Long Head of the Biceps Brachii: Nonoperative Treatment Approaches.

    PubMed

    Wilk, Kevin E; Hooks, Todd R

    2016-01-01

    The long head of the biceps has garnered increased attention and interest due to the high prevalence of pain that can be a primary condition or occur secondary to shoulder dysfunction. The successful treatment of biceps tendinopathy is dependent on an accurate diagnosis and recognizing all causative factors. The treatment program will be individualized with a rehabilitation program designed to restore strength and flexibility and restore normal tendon mechanics.

  7. Effects of a multichannel dynamic functional electrical stimulation system on hemiplegic gait and muscle forces

    PubMed Central

    Qian, Jing-guang; Rong, Ke; Qian, Zhenyun; Wen, Chen; Zhang, Songning

    2015-01-01

    [Purpose] The purpose of the study was to design and implement a multichannel dynamic functional electrical stimulation system and investigate acute effects of functional electrical stimulation of the tibialis anterior and rectus femoris on ankle and knee sagittal-plane kinematics and related muscle forces of hemiplegic gait. [Subjects and Methods] A multichannel dynamic electrical stimulation system was developed with 8-channel low frequency current generators. Eight male hemiplegic patients were trained for 4 weeks with electric stimulation of the tibia anterior and rectus femoris muscles during walking, which was coupled with active contraction. Kinematic data were collected, and muscle forces of the tibialis anterior and rectus femoris of the affected limbs were analyzed using a musculoskelatal modeling approach before and after training. A paired sample t-test was used to detect the differences between before and after training. [Results] The step length of the affected limb significantly increased after the stimulation was applied. The maximum dorsiflexion angle and maximum knee flexion angle of the affected limb were both increased significantly during stimulation. The maximum muscle forces of both the tibia anterior and rectus femoris increased significantly during stimulation compared with before functional electrical stimulation was applied. [Conclusion] This study established a functional electrical stimulation strategy based on hemiplegic gait analysis and musculoskeletal modeling. The multichannel functional electrical stimulation system successfully corrected foot drop and altered circumduction hemiplegic gait pattern. PMID:26696734

  8. Tissue reactivity and suture handling characteristics of “jimat” against silk and chromic gut in cat thigh muscle: A comparative study

    PubMed Central

    Bekele, Tilahun; Bhokre, A. P.; Tesfaye, Abreha

    2015-01-01

    Aim: This study was conducted to evaluate and compare the tissue reactivity and suture handling characteristics of chromic gut, silk, and ‘jimat’ suture materials in cat thigh muscle. Materials and Methods: This experimental study was conducted from November, 2013 to April, 2014 in Kombolcha Animal Diseases Survey, Research and Diagnostic Laboratory, Kombolcha, Ethiopia. A total of 36 local breed male cats were randomly assigned into chromic gut, silk, and “jimat” groups of 12 cats each as A, B, and C, respectively. The hind leg muscle biceps femoris was incised and sutured with suture materials according to their groups. The muscle samples with its suture were collected at six different days interval i.e. 1, 3, 7, 14, 21, and 28 and processed histopathologically to assess the degree of leukocytic infiltration and fibrous and granulation tissue formation (GTF). In addition, all suture materials were evaluated intraoperatively about their handling characteristics, by rating the precision of knot tying, square knot positioning, and resistance to knot slippage. The statistical analysis was done with two-way ANOVA, Kruskal–Wallis, and Chi-square tests. Results: The histopathology showed that “jimat” thread (2.4±1.2) had produced least leukocytic infiltration than chromic gut (4.5±1.9) and silk (4.3±1.5) sutures during the study period. Higher GTF was seen at day 3 (6 [100%]), 7 (6 [100%]) and day 14 (4 [66.7%]) in all sutures, whereas “jimat” showed significantly (p<0.05) higher fibrous tissue formation (10 [83.3%]) than others. Moreover, “jimat” suture had equal suture handling characteristics (p>0.05) with both chromic gut and silk. Conclusion: The result indicated that a single strand “jimat” thread appears to be the most satisfactory suture material as regards to both tissue reaction and suture handling characteristics for skeletal muscle approximation in cats and provided that studies on its carcinogenic effects should be done. PMID

  9. Protein synthesis assessed by ribosome analysis in human papillary muscle in relation to oxidative capacity: a comparison with skeletal muscle.

    PubMed

    Wernerman, J; Sylvén, C; von der Decken, A; Jansson, E; Böök, K; Vinnars, E

    1988-08-01

    Protein synthesis as assessed by the concentration and size distribution of ribosomes was determined together with citrate synthase activity in papillary muscles obtained at open heart surgery from patients with mitral valve disease. The results were compared with corresponding data from the quadriceps femoris muscle of patients undergoing cholecystectomy. Citrate synthase activity was six times higher in papillary muscle than in skeletal muscle. The total ribosome concentration per mg DNA was similar in the two types of muscle. Compared with skeletal muscle, in papillary muscle polyribosomes constituted a higher proportion of the ribosomes (p less than 0.001), and there was a tendency towards larger polyribosome aggregates. It is proposed that the high concentration of polyribosomes in papillary muscle is related to the high oxidative capacity of that tissue.

  10. Corticospinal excitability of the biceps brachii is higher during arm cycling than an intensity-matched tonic contraction.

    PubMed

    Forman, Davis; Raj, Amita; Button, Duane C; Power, Kevin E

    2014-09-01

    Human studies have not assessed corticospinal excitability of an upper-limb prime mover during arm cycling. The purpose of the present study was to determine whether supraspinal and/or spinal motoneuron excitability of the biceps brachii was different between arm cycling and an intensity-matched tonic contraction. We hypothesized that spinal motoneuron excitability would be higher during arm cycling than an intensity-matched tonic contraction. Supraspinal and spinal motoneuron excitability were assessed using transcranial magnetic stimulation (TMS) of the motor cortex and transmastoid electrical stimulation (TMES) of the corticospinal tract, respectively. TMS-induced motor-evoked potentials (MEPs) and TMES-induced cervicomedullary-evoked potentials (CMEPs) were assessed at three separate positions (3, 6, and 12 o'clock relative to a clock face) during arm cycling and an intensity-matched tonic contraction. MEP amplitudes were 7.2 and 8.8% maximum amplitude of the compound muscle action potential (Mmax) larger during arm cycling compared with a tonic contraction at the 3 (P < 0.001) and 6 o'clock (P < 0.001) positions, respectively. There was no difference between tasks during elbow extension (12 o'clock). CMEP amplitudes were 5.2% Mmax larger during arm cycling compared with a tonic contraction at the 3 o'clock position (P < 0.001) with no differences seen at midflexion (6 o'clock) or extension (12 o'clock). The data indicate an increase in the excitability of corticospinal neurons, which ultimately project to biceps brachii during the elbow flexion portion of arm cycling, and increased spinal motoneuron excitability at the onset of elbow flexion during arm cycling. We conclude that supraspinal and spinal motoneuron excitability are phase- and task-dependent.

  11. Interprofessional analysis of esthetical deformity from long head biceps tenotomy

    PubMed Central

    Almeida, Alexandre; Valin, Márcio Rangel; Lotti, Cleber; de Almeida, Nayvaldo Couto; Agostini, Ana Paula

    2015-01-01

    OBJECTIVE: To evaluate the perception of an esthetical deformity resultant from arthroscopic long head biceps (LHB) tenotomy according to the degree of experience of the assisting professional. METHODS: 120 patients submitted to shoulder surgery were photographed and photos were mounted in a PowerPoint presentation. Three shoulder specialist surgeons, three generalist orthopedic surgeons and three graduated residents analyzed the presentation. RESULTS: On all patients we observed most agreement among the shoulder specialists. When just the patients with LHB tenotomy were analyzed, the specialists agreed moderately, the generalists had small agreement and the residents, a poor one. Analyzing patients with BMI < 30, there was major agreement between the specialists, while the generalists and residents had poor agreement. Analyzing patients with BMI ≥ 30, the generalists had small kappa agreement, while the specialists and residents had no agreement. CONCLUSIONS: The perception of an esthetical deformity regarding a LHB tenotomy did not have significant agreement between different level of professionals, even though the specialists showed similar perception on tenotomy patients. The evaluation of obese patients lowered the agreement on the three groups of professionals. Level of Evidence III. Case Control Study. PMID:26207087

  12. Toward an understanding of foreground emission in the BICEP2 region

    SciTech Connect

    Flauger, Raphael; Hill, J. Colin; Spergel, David N. E-mail: jch@astro.princeton.edu

    2014-08-01

    BICEP2 has reported the detection of a degree-scale B-mode polarization pattern in the Cosmic Microwave Background (CMB) and has interpreted the measurement as evidence for primordial gravitational waves. Motivated by the profound importance of the discovery of gravitational waves from the early Universe, we examine to what extent a combination of Galactic foregrounds and lensed E-modes could be responsible for the signal. We reanalyze the BICEP2 results and show that the 100 ×150 GHz and 150 ×150 GHz data are consistent with a cosmology with r=0.2 and negligible foregrounds, but also with a cosmology with r=0 and a significant dust polarization signal. We give independent estimates of the dust polarization signal in the BICEP2 region using a number of different approaches: (1) data-driven models based on Planck 353 GHz intensity, polarization fractions inferred from the same Planck data used by the BICEP2 team but corrected for CMB and CIB contributions, and polarization angles from starlight polarization data or the Planck sky model; (2) the same set of pre-Planck models used by the BICEP2 team but taking into account the higher polarization fractions observed in the CMB- and CIB-corrected map; (3) a measurement of neutral hydrogen gas column density N{sub HI} in the BICEP2 region combined with an extrapolation of a relation between HI column density and dust polarization derived by Planck; and (4) a dust polarization map based on digitized Planck data, which we only use as a final cross-check. While these approaches are consistent with each other, the expected amplitude of the dust polarization power spectrum remains uncertain by about a factor of three. The lower end of the prediction leaves room for a primordial contribution, but at the higher end the dust in combination with the standard CMB lensing signal could account for the BICEP2 observations, without requiring the existence of primordial gravitational waves. By measuring the cross-correlations between

  13. [Tensiomyography as method of evaluating muscles status].

    PubMed

    Markulincić, Branko; Muraja, Sonja

    2007-01-01

    Sports results, as well as results of rehabilitation treatments are closely related to a detailed, strictly individualized programme of sports and rehabilitation training. It is vitally important to monitor and evaluate results constantly. Along with already standardized methods of evaluating neuromuscular system, such as electrodinamometry and isokinetic dinamometry on Cybex; tensiomyography (TMG) as method of assessing muscles status has been introduced. TMG is non-invasive, selective, objective method designed to measure time of activation, delay time as well as contraction time, relaxation time and intesity of muscle contraction in conditions of submaximum electrostimulation. The method is based on measuring the muscle belly enlargements by a superficialy placed precise electromagnetic sensor.TMG enables the examination of some otherwise inaccessible muscles like gluteus maximus muscle and also selective evaluation of single muscle head (for example m. vastus medialis, m. vastus lateralis and m. rectus femoris of m. quadriceps). Estimation of harmonisation between agonistic and antagonistic muscles, synergistic muscles and same muscles on left and right side of the body, is based on muscles biomechanical properties i.e. parameters, calculated from TMG response. Total harmonization (100%) is hardly ever the case, the lowest level sufficient muscle groups functionality is defined by 80% for lateral and 65% for agonistic/synergistic harmonisation. Harmonization below this level either reflects past injures, muscle adaptation or indicates increased exposure to injury.

  14. Differences in muscle mechanical properties between elite power and endurance athletes: a comparative study.

    PubMed

    Loturco, Irineu; Gil, Saulo; Laurino, Cristiano Frota de Souza; Roschel, Hamilton; Kobal, Ronaldo; Cal Abad, Cesar C; Nakamura, Fabio Y

    2015-06-01

    The aim of this study was to compare muscle mechanical properties (using tensiomyography-TMG) and jumping performance of endurance and power athletes and to quantify the associations between TMG parameters and jumping performance indices. Forty-one high-level track and field athletes from power (n = 22; mean ± SD age, height, and weight were 27.2 ± 3.6 years; 180.2 ± 5.4 cm; and 79.4 ± 8.6 kg, respectively) and endurance (endurance runners and triathletes; n = 19; mean ± SD age, height, and weight were 27.1 ± 6.9 years; 169.6 ± 9.8 cm; 62.2 ± 13.1 kg, respectively) specialties had the mechanical properties of their rectus femoris (RF) and biceps femoris (BF) assessed by TMG. Muscle displacement (Dm), contraction time (Tc), and delay time (Td) were retained for analyses. Furthermore, they performed squat jumps (SJs), countermovement jumps (CMJs), and drop jumps to assess reactive strength index (RSI), using a contact platform. Comparisons between groups were performed using differences based on magnitudes, and associations were quantified by the Spearman's ρ correlation. Power athletes showed almost certain higher performance in all jumping performance indices when compared with endurance athletes (SJ = 44.9 ± 4.1 vs. 30.7 ± 6.8 cm; CMJ = 48.9 ± 4.5 vs. 33.6 ± 7.2 cm; RSI = 2.19 ± 0.58 vs. 0.84 ± 0.39, for power and endurance athletes, mean ± SD, respectively; 00/00/100, almost certain, p ≤ 0.05), along with better contractile indices reflected by lower Dm, Tc, and Td (Tc BF = 14.3 ± 2.3 vs. 19.4 ± 3.3 milliseconds; Dm BF = 1.67 ± 1.05 vs. 4.23 ± 1.75 mm; Td BF = 16.8 ± 1.6 vs. 19.6 ± 1.3 milliseconds; Tc RF = 18.3 ± 2.8 vs. 22.9 ± 4.0 milliseconds; Dm RF = 4.98 ± 3.71 vs. 8.88 ± 3.45 mm; Td RF = 17.5 ± 1.0 vs. 20.9 ± 1.6 milliseconds, for power and endurance athletes, mean ± SD, respectively; 00/00/100, almost certain, p ≤ 0.05). Moderate correlations (Spearman's ρ between -0.61 and -0.72) were found between TMG and jumping

  15. Use of MMG signals for the control of powered orthotic devices: development of a rectus femoris measurement protocol.

    PubMed

    Antonelli, Michele Gabrio; Zobel, P Beomonte; Giacomin, J

    2009-01-01

    A test protocol is defined for the purpose of measuring rectus femoris mechanomyographic (MMG) signals. The protocol is specified in terms of the following: measurement equipment, signal processing requirements, human postural requirements, test rig, sensor placement, sensor dermal fixation, and test procedure. Preliminary tests of the statistical nature of rectus femoris MMG signals were performed, and Gaussianity was evaluated by means of a two-sided Kolmogorov-Smirnov test. For all 100 MMG data sets obtained from the testing of two volunteers, the null hypothesis of Gaussianity was rejected at the 1%, 5%, and 10% significance levels. Most skewness values were found to be greater than 0.0, while all kurtosis values were found to be greater than 3.0. A statistical convergence analysis also performed on the same 100 MMG data sets suggested that 25 MMG acquisitions should prove sufficient to statistically characterize rectus femoris MMG. This conclusion is supported by the qualitative characteristics of the mean rectus femoris MMG power spectral densities obtained using 25 averages.

  16. Event-related differences in the cross-sectional areas and torque generation capabilities of quadriceps femoris and hamstrings in male high school athletes.

    PubMed

    Hoshikawa, Yoshihiro; Muramatsu, Masataka; Iida, Tomomi; Uchiyama, Akiko; Nakajima, Yoshiharu; Kanehisa, Hiroaki

    2010-01-01

    This study investigated the event-related differences in the cross-sectional areas (CSAs) and torque generation capabilities of the quadriceps femoris (QF) and hamstrings (HAM) in male high school athletes. Subjects were soccer players (n=32), volleyball players (21), rowers (29), karate athletes (18), sumo wrestlers (15), sprinters (22), throwers (16), and nonathletes (20). The CSAs of QF and HAM at the mid-thigh were determined using magnetic resonance imaging. In addition, isokinetic torques during knee extension and flexion were determined at a pre-set velocity of 1.05 rad/s. The CSAs of the two muscle groups and torques developed in the two motions were significantly related to the two-third power of lean body mass (LBM(2/3)) and the product of CSA and femur length (CSA*fl), calculated as an index of muscle volume, respectively. CSA relative to LBM(2/3) for QF did not differ among the groups, but that for HAM was higher in sprinters, soccer players, throwers, and karate athletes than in sumo wrestlers, rowers, volleyball players, and nonathletes. Knee extension torque relative to the CSA*fl of QF was higher in karate athletes, soccer players, and rowers than in nonathletes, but the corresponding value for knee flexion did not differ among groups. Thus, the present study indicated that, at least in male high school athletes, the event-related differences in LBM and the muscularity of QF and HAM produced the corresponding differences in the CSAs of the reciprocal muscle groups and knee extension and flexion torques, respectively. However, specific profiles related to competitive and/or training styles exist in HAM CSA and knee extension torque, which cannot be explained by the magnitude of LBM and QF CSA, respectively.

  17. Endoscopic Extra-articular Surgical Removal of Heterotopic Ossification of the Rectus Femoris Tendon in a Series of Athletes

    PubMed Central

    Comba, Fernando; Piuzzi, Nicolás S.; Oñativia, José Ignacio; Zanotti, Gerardo; Buttaro, Martín; Piccaluga, Francisco

    2016-01-01

    Background: Calcific deposits in tendon, muscles, and periarticular areas are very common. Heterotopic ossification of the rectus femoris (HORF) is a rare condition, and several theories exist regarding the etiopathogenesis, which appears to be multifactorial with traumatic, genetic, and local metabolic factors involved. Although HORF typically responds to nonoperative treatment, when this approach fails, endoscopic treatment is a minimally invasive technique to address the pathology. Purpose: To report the clinical and radiological outcomes of 9 athletes with HORF who underwent endoscopic resection. Study Design: Case series; Level of evidence, 4. Methods: Nine male athletes were treated with endoscopic extra-articular resection of HORF after failure of a 6-month course of nonoperative treatment. All patients were studied with radiographs, computed tomography, and magnetic resonance imaging. Outcomes were assessed clinically using the modified Harris Hip Score (mHHS), a visual analog scale for sport activity–related pain (VAS-SRP), patient satisfaction, and ability and time to return to the preoperative sport level. Radiographic assessment was performed to determine recurrence. Results: The mean age of the patients was 32 years (range, 23-47 years). Mean follow-up was 44 months (range, 14-73 months). All patients had improved mHHS scores from a mean preoperative of 65.6 (SD, 8.2) to 93.9 (SD, 3.6). Pain decreased from a mean 8.2 preoperatively (SD, 0.9) to 0.4 (SD, 0.7) at last follow-up. There were no complications, and all patients were able to return to their previous sports at the same level except for 1 recreational athlete. There was only 1 radiological recurrence at last follow-up in an asymptomatic patient. Conclusion: To our knowledge, this is the largest case series of athletes with HORF treated with endoscopic resection. We found this extra-articular endoscopic technique to be safe and effective, showing clinical outcome improvement and 90% chance of

  18. Initial experience with proximal ligation for profunda femoris artery aneurysms: report of three cases.

    PubMed

    Shintani, Tsunehiro; Norimatsu, Togo; Atsuta, Koji; Saitou, Takaaki; Higashi, Shigeki; Mitsuoka, Hiroshi

    2014-04-01

    Profunda femoris artery aneurysms (PFAAs) are rare and difficult to diagnose in the early stage. They are often found due to the presence of complicated conditions, such as rapid expansion, rupture, or acute lower limb ischemia. Surgical procedures such as aneurysmectomy and endoaneurysmorrhaphy tend to be technically challenging because of the patient status and the extent of the aneurysm. We experienced three cases of PFAAs that were treated by proximal ligation (PL) without complete control of the distal branches. The exclusion of PFAAs was confirmed by duplex ultrasound or angiography at the end of the operation. There was no mortality in the perioperative period. During a 12-month follow-up, all cases exhibited complete exclusion of aneurysms with marked size reduction. Based on these findings, we propose that PL, with a careful follow-up for PFAA exclusion and distal limb circulation, could be an alternative treatment for complicated PFAAs.

  19. Rules of tissue packing involving different cell types: human muscle organization

    PubMed Central

    Sánchez-Gutiérrez, Daniel; Sáez, Aurora; Gómez-Gálvez, Pedro; Paradas, Carmen; Escudero, Luis M.

    2017-01-01

    Natural packed tissues are assembled as tessellations of polygonal cells. These include skeletal muscles and epithelial sheets. Skeletal muscles appear as a mosaic composed of two different types of cells: the “slow” and “fast” fibres. Their relative distribution is important for the muscle function but little is known about how the fibre arrangement is established and maintained. In this work we capture the organizational pattern in two different healthy muscles: biceps brachii and quadriceps. Here we show that the biceps brachii muscle presents a particular arrangement, based on the different sizes of slow and fast fibres. By contrast, in the quadriceps muscle an unbiased distribution exists. Our results indicate that the relative size of each cellular type imposes an intrinsic organization into natural tessellations. These findings establish a new framework for the analysis of any packed tissue where two or more cell types exist. PMID:28071729

  20. Rules of tissue packing involving different cell types: human muscle organization.

    PubMed

    Sánchez-Gutiérrez, Daniel; Sáez, Aurora; Gómez-Gálvez, Pedro; Paradas, Carmen; Escudero, Luis M

    2017-01-10

    Natural packed tissues are assembled as tessellations of polygonal cells. These include skeletal muscles and epithelial sheets. Skeletal muscles appear as a mosaic composed of two different types of cells: the "slow" and "fast" fibres. Their relative distribution is important for the muscle function but little is known about how the fibre arrangement is established and maintained. In this work we capture the organizational pattern in two different healthy muscles: biceps brachii and quadriceps. Here we show that the biceps brachii muscle presents a particular arrangement, based on the different sizes of slow and fast fibres. By contrast, in the quadriceps muscle an unbiased distribution exists. Our results indicate that the relative size of each cellular type imposes an intrinsic organization into natural tessellations. These findings establish a new framework for the analysis of any packed tissue where two or more cell types exist.

  1. Actions of Two Bi-Articular Muscles of the Lower Extremity: A Review

    PubMed Central

    Landin, Dennis; Thompson, Melissa; Reid, Meghan

    2016-01-01

    The extremities of the human body contain several bi-articular muscles. The actions produced by muscles at the joints they cross are greatly influenced by joint moment arms and muscle length. These factors are dynamic and subject to change as joint angles are altered. Therefore, to more completely understand the actions of such muscles, the angles of both joints must be manipulated. This report reviews investigations, which have explored the actions of two bi-articular muscles of the lower extremities (gastrocnemius and rectus femoris) as the joints they cross are moved into various combinations of angles. The findings have both clinical and physical performance ramifications. PMID:27298656

  2. The ligamentum capitis femoris: anatomic, magnetic resonance and computed tomography study.

    PubMed

    Perez-Carro, Luis; Golano, Pau; Vega, Jordi; Escajadillo, Natalia F; Rubin, Carlos G; Cerezal, Luis

    2011-01-01

    The objective of the study was to describe the normal anatomy of the ligamentum capitis femoris and to determine the neurovascular structures potentially at risk during its reconstruction. Ten cadaveric specimens of the ligamentum capitis femoris (LCF) were dissected and photographed. Magnetic resonance (MR) and Computed tomography (CT) arthrography evaluation of the anatomy of the LCF in 30 hips were performed to measure length of the ligament and to study the proximity of neurovascular structures. The anatomical study showed that the LCF has a pyramidal structure and a banded appearance. The thickness of the medial wall of the acetabulum 3 mm superior to the inferior acetabular boundary was found to be 6.7 mm (4-9 mm) at point 1 (anterior), 4.1 mm (3-7 mm) at point 2 (central), and 6.5 mm (4-9 mm) at point 3 (posterior). Central anchors or screws were found to lie within 1.7 cm (1.6-1.9 cm) of the external iliac vein and artery. Angulation of anchors in the anterior and posterior columns in the axial plane with respect to acetabular fossa floor (the Optimal Angulation Angle or OAA), is safer (0 to 45º the safest optimal angles). The sagittal angulation created by the safe pathway in the anterior and posterior columns with respect to the plane of the facies lunata in this area was also measured and termed the Optimal Angle of Penetration (OAP) with normal values being: 110º (102-123º) for the posterior column and 90º (85-94º) for the anterior column. Our results suggest that reconstruction of the LCF can be safely performed if these guidelines are followed.

  3. Atrophy of the quadriceps muscle in children with a painful hip.

    PubMed

    Robben, S G; Lequin, M H; Meradji, M; Diepstraten, A F; Hop, W C

    1999-09-01

    The objective of this study was to determine the degree of muscle wasting of various components of the quadriceps muscle in children with a painful hip. Between January 1994 and September 1997, 327 consecutive children with a unilateral painful hip and/or limping were evaluated prospectively with ultrasonography. Quadriceps thickness was measured on both sides. Moreover, muscle thickness was measured in 59 control subjects. The patients were divided into eight groups; transient synovitis (n = 134), Perthes' disease (n = 35), slipped capital femoral epiphysis (n = 5), osteomyelitis (n = 4), aspecific synovitis (n = 5), rheumatoid arthritis (n = 3) and miscellaneous (n = 16). In 125 patients, no sonographic and radiological abnormalities were found and during follow-up the symptoms disappeared ('no pathology' group). Ipsilateral muscle wasting was present in all patient groups, whereas the control subjects showed no significant difference in muscle thickness between legs. The degree of muscle wasting was compared between transient synovitis, the 'no pathology' group, Perthes' disease and control subjects. For both quadriceps and vastus intermedius muscles, there was a significant difference between these groups, except between control subjects and the 'no pathology' group. For the rectus femoris muscle, there was a significant difference between these groups, except between transient synovitis and 'no pathology'. Muscle wasting showed a positive correlation with duration of symptoms and pre-existing muscle mass. In conclusion, different diseases show different degrees of muscle wasting, and there are different patterns of muscle wasting of various components of the quadriceps femoris muscle.

  4. BICEP2/Keck Array. VII. Matrix Based E/B Separation Applied to Bicep2 and the Keck Array

    NASA Astrophysics Data System (ADS)

    BICEP2 Collaboration; Keck Array Collaboration; Ade, P. A. R.; Ahmed, Z.; Aikin, R. W.; Alexander, K. D.; Barkats, D.; Benton, S. J.; Bischoff, C. A.; Bock, J. J.; Bowens-Rubin, R.; Brevik, J. A.; Buder, I.; Bullock, E.; Buza, V.; Connors, J.; Crill, B. P.; Duband, L.; Dvorkin, C.; Filippini, J. P.; Fliescher, S.; Grayson, J.; Halpern, M.; Harrison, S.; Hildebrandt, S. R.; Hilton, G. C.; Hui, H.; Irwin, K. D.; Kang, J.; Karkare, K. S.; Karpel, E.; Kaufman, J. P.; Keating, B. G.; Kefeli, S.; Kernasovskiy, S. A.; Kovac, J. M.; Kuo, C. L.; Leitch, E. M.; Lueker, M.; Megerian, K. G.; Namikawa, T.; Netterfield, C. B.; Nguyen, H. T.; O'Brient, R.; Ogburn, R. W., IV; Orlando, A.; Pryke, C.; Richter, S.; Schwarz, R.; Sheehy, C. D.; Staniszewski, Z. K.; Steinbach, B.; Sudiwala, R. V.; Teply, G. P.; Thompson, K. L.; Tolan, J. E.; Tucker, C.; Turner, A. D.; Vieregg, A. G.; Weber, A. C.; Wiebe, D. V.; Willmert, J.; Wong, C. L.; Wu, W. L. K.; Yoon, K. W.

    2016-07-01

    A linear polarization field on the sphere can be uniquely decomposed into an E-mode and a B-mode component. These two components are analytically defined in terms of spin-2 spherical harmonics. Maps that contain filtered modes on a partial sky can also be decomposed into E-mode and B-mode components. However, the lack of full sky information prevents orthogonally separating these components using spherical harmonics. In this paper, we present a technique for decomposing an incomplete map into E and B-mode components using E and B eigenmodes of the pixel covariance in the observed map. This method is found to orthogonally define E and B in the presence of both partial sky coverage and spatial filtering. This method has been applied to the Bicep2 and the Keck Array maps and results in reducing E to B leakage from ΛCDM E-modes to a level corresponding to a tensor-to-scalar ratio of r\\lt 1× {10}-4.

  5. Neurophysiological correlates of aging-related muscle weakness

    PubMed Central

    Cunningham, David A.; Bonnett, Corin; Gohar, Dina; Bayram, Mehmed; Wyant, Alexandria; Varnerin, Nicole; Mamone, Bernadett; Siemionow, Vlodek; Hou, Juliet; Machado, Andre; Yue, Guang H.

    2013-01-01

    Muscle weakness associated with aging implicates central neural degeneration. However, role of the primary motor cortex (M1) is poorly understood, despite evidence that gains in strength in younger adults are associated with its adaptations. We investigated whether weakness of biceps brachii in aging analogously relates to processes in M1. We enrolled 20 young (22.6 ± 0.87 yr) and 28 old (74.79 ± 1.37 yr) right-handed participants. Using transcranial magnetic stimulation, representation of biceps in M1 was identified. We examined the effect of age and sex on strength of left elbow flexion, voluntary activation of biceps, corticospinal excitability and output, and short-interval intracortical and interhemispheric inhibition. Interhemispheric inhibition was significantly exaggerated in the old (P = 0.047), while strength tended to be lower (P = 0.075). Overall, women were weaker (P < 0.001). Processes of M1 related to strength or voluntary activation of biceps, but only in older adults. Corticospinal excitability was lower in weaker individuals (r = 0.38), and corticospinal output, intracortical inhibition and interhemispheric inhibition were reduced too in individuals who poorly activated biceps (r = 0.43, 0.54 and 0.38). Lower intracortical inhibition may reflect compensation for reduced corticospinal excitability, allowing weaker older adults to spread activity in M1 to recruit synergists and attempt to sustain motor output. Exaggerated interhemispheric inhibition, however, conflicts with previous evidence, potentially related to greater callosal damage in our older sample, our choice of proximal vs. distal muscle and differing influence of measurement of inhibition in rest vs. active states of muscle. Overall, age-specific relation of M1 to strength and muscle activation emphasizes that its adaptations only emerge when necessitated, as in a weakening neuromuscular system in aging. PMID:24027104

  6. Effect of prolonged bed rest on the anterior hip muscles.

    PubMed

    Dilani Mendis, M; Hides, Julie A; Wilson, Stephen J; Grimaldi, Alison; Belavý, Daniel L; Stanton, Warren; Felsenberg, Dieter; Rittweger, Joern; Richardson, Carolyn

    2009-11-01

    Prolonged bed rest and inactivity is known to cause muscular atrophy with previous research indicating that muscles involved in joint stabilisation are more susceptible. The anterior hip muscles are important for hip joint function and stability but little is known about the effects of prolonged inactivity on their function. This study investigated the effect of prolonged bed rest on the size of the anterior hip muscles and their pattern of recovery. The effect of resistive vibration exercise (RVE) as a countermeasure to muscle atrophy was also investigated. 12 male participants, randomly assigned to either a control or an exercise group, underwent 8 weeks of bed rest with 6 months follow-up. Changes in muscle cross-sectional area (CSA) of the iliacus, psoas, iliopsoas, sartorius and rectus femoris muscles were measured by magnetic resonance imaging at regular intervals during bed rest and recovery phases. CSAs of iliopsoas and sartorius decreased at the hip joint (p<0.05) during bed rest but iliacus, psoas, and rectus femoris CSAs were unchanged (p>0.05). No significant difference was found between the two groups for all muscles (all p>0.1), suggesting inefficacy of the countermeasure in this sample. These findings suggest that prolonged bed rest can result in the atrophy of specific muscles across the hip joint which may affect its stability and function.

  7. Optimizing Muscle Parameters in Musculoskeletal Modeling Using Monte Carlo Simulations

    NASA Technical Reports Server (NTRS)

    Hanson, Andrea; Reed, Erik; Cavanagh, Peter

    2011-01-01

    Astronauts assigned to long-duration missions experience bone and muscle atrophy in the lower limbs. The use of musculoskeletal simulation software has become a useful tool for modeling joint and muscle forces during human activity in reduced gravity as access to direct experimentation is limited. Knowledge of muscle and joint loads can better inform the design of exercise protocols and exercise countermeasure equipment. In this study, the LifeModeler(TM) (San Clemente, CA) biomechanics simulation software was used to model a squat exercise. The initial model using default parameters yielded physiologically reasonable hip-joint forces. However, no activation was predicted in some large muscles such as rectus femoris, which have been shown to be active in 1-g performance of the activity. Parametric testing was conducted using Monte Carlo methods and combinatorial reduction to find a muscle parameter set that more closely matched physiologically observed activation patterns during the squat exercise. Peak hip joint force using the default parameters was 2.96 times body weight (BW) and increased to 3.21 BW in an optimized, feature-selected test case. The rectus femoris was predicted to peak at 60.1% activation following muscle recruitment optimization, compared to 19.2% activation with default parameters. These results indicate the critical role that muscle parameters play in joint force estimation and the need for exploration of the solution space to achieve physiologically realistic muscle activation.

  8. EMG analysis of human postural responses during parabolic flight microgravity episodes

    NASA Technical Reports Server (NTRS)

    Layne, Charles S.; Spooner, Brian S.

    1990-01-01

    Anticipatory postural activity in the trunk and legs precedes rapid shoulder flexion in unit gravity. The hypothesis that anticipatory activity is a component of a single neural command for arm movement was tested by monitoring the surface electromyographic activity of the biceps femoris, paraspinals, and deltoid muscles of three subjects during the microgravity phase of parabolic flight. If part of a single command, anticipatory postural activity would be expected to remain intact despite the absence of the body's center of gravity in a reduced gravity environment. However, in at least 75 percent of the microgravity trials anticipatory biceps femoris activity was absent, indicating a separation of postural and agonist muscle activity. Such a finding suggests that anticipatory postural biceps femoris activity may be initiated independently of agonist (deltoid) activity.

  9. Final Results from Three Years of Observations with the BICEP Telescope

    NASA Astrophysics Data System (ADS)

    Bischoff, Colin

    2013-04-01

    The BICEP (Background Imaging of Cosmic Extragalactic Polarization) telescope is the first instrument designed specifically to search for the signature of inflation using the polarization of the Cosmic Microwave Background at degree angular scales. BICEP combines polarization sensitive bolometers, operating at 100 and 150 GHz, with a small aperture cryogenic refracting telescope. It operated for three seasons from 2006 through 2008 at the Amundsen-Scott South Pole Station. Results from the first two seasons, published in Chiang et al. (2010), have so far provided the tightest upper limits on B-mode polarization of the CMB. We report on new results that incorporate the full three year data set to improve this constraint. Besides including more data, the new analysis uses a novel method to deproject the dominant source of systematic contamination in BICEP data. The successful design of BICEP is the basis of BICEP2, which operated at the South Pole from 2010 through 2012, and the Keck Array, which began observations in 2011 and is still operating. These experiments are currently producing extremely deep maps of CMB polarization.

  10. Quantitative MRI and strength measurements in the assessment of muscle quality in Duchenne muscular dystrophy.

    PubMed

    Wokke, B H; van den Bergen, J C; Versluis, M J; Niks, E H; Milles, J; Webb, A G; van Zwet, E W; Aartsma-Rus, A; Verschuuren, J J; Kan, H E

    2014-05-01

    The purpose of this study was to assess leg muscle quality and give a detailed description of leg muscle involvement in a series of Duchenne muscular dystrophy patients using quantitative MRI and strength measurements. Fatty infiltration, as well as total and contractile (not fatty infiltrated) cross sectional areas of various leg muscles were determined in 16 Duchenne patients and 11 controls (aged 8-15). To determine specific muscle strength, four leg muscle groups (quadriceps femoris, hamstrings, anterior tibialis and triceps surae) were measured and related to the amount of contractile tissue. In patients, the quadriceps femoris showed decreased total and contractile cross sectional area, attributable to muscle atrophy. The total, but not the contractile, cross sectional area of the triceps surae was increased in patients, corresponding to hypertrophy. Specific strength decreased in all four muscle groups of Duchenne patients, indicating reduced muscle quality. This suggests that muscle hypertrophy and fatty infiltration are two distinct pathological processes, differing between muscle groups. Additionally, the quality of remaining muscle fibers is severely reduced in the legs of Duchenne patients. The combination of quantitative MRI and quantitative muscle testing could be a valuable outcome parameter in longitudinal studies and in the follow-up of therapeutic effects.

  11. Test-retest reliability of wavelet - and Fourier based EMG (instantaneous) median frequencies in the evaluation of back and hip muscle fatigue during isometric back extensions.

    PubMed

    Coorevits, Pascal; Danneels, Lieven; Cambier, Dirk; Ramon, Herman; Druyts, Hans; Karlsson, J Stefan; De Moor, Georges; Vanderstraeten, Guy

    2008-10-01

    The present study aimed at assessing the test-retest reliability of wavelet - and Fourier derived (instantaneous) median frequencies of surface electromyographic (EMG) measurements of back and hip muscles during isometric back extensions. Twenty healthy subjects (10 males and 10 females) performed a modified Biering-Sørensen test on two separate days, with a 1-week interval between the two tests. Surface EMG measurements were bilaterally performed from the latissimus dorsi, the thoracic and lumbar parts of the longissimus thoracis, the thoracic and lumbar parts of the iliocostalis lumborum, the multifidus, the gluteus maximus and the biceps femoris. In addition, three-dimensional kinematic data were recorded of the subjects' lumbar vertebrae. The (instantaneous) median frequencies were calculated from the EMG signals using continuous wavelet (IMDF) - and short-time Fourier transforms (MDF). Linear regressions performed on the IMDF and MDF data as a function of time yielded slopes (IMDF(slope) and MDF(slope)) and intercepts (IMDF(init) and MDF(init)) of the regression lines. Test-retest reliability was assessed on the normalized slopes and intercept parameters by means of intraclass correlation coefficients (ICC) and standard errors of measurements expressed as percentages of the mean values (% SEM). The results of IMDF(slope) and MDF(slope) parameters indicated ICCs for back and hip muscles between .443 and .727 for IMDF(slope), values between .273 and .734 for MDF(slope), % SEM between 7.6% and 58.9% for IMDF(slope) and % SEM between 8.2% and 25.3% for MDF(slope), respectively. The ICCs for IMDF(init) and MDF(init) parameters varied between .376 and .907 for IMDF(init) and between .383 and .883 for MDF(init), and % SEM ranged from 2.7% to 6.3% for IMDF(init) and from 2.6% to 4.7% for MDF(init), respectively. These results indicate that both wavelet - and Fourier based (instantaneous) median frequency parameters generally are reliable in the analysis of back and

  12. Analysis of upper arm muscle activation using surface electromyography signals during drum playing

    PubMed Central

    Chong, Hyun Ju; Kwon, Chun-Ki; Kang, Hyun-Joo; Kim, Soo Ji

    2016-01-01

    This study measured surface electromyography of the biceps brachii and triceps brachii during repeated drum playing with and without a drumstick to better understand activation of the upper arm muscles and inform the use of instrument playing for motor rehabilitation. A total of 40 healthy college students participated in this study. All participants were asked to strike a drum with their hand and with a drumstick at three different levels of stroke: soft, medium, and strong. The stroke order was randomly assigned to participants. A sound level meter was used to record the intensity of the drum playing. Surface electromyography signals were recorded at every hit during drum playing both with and without the drumstick in each of the three stroke conditions. The results demonstrated that the highest muscle activation was observed in both biceps brachii and triceps brachii with strong drum playing with and without the drumstick. A two-way repeated measures analysis of variance showed that there was a significant main effect for stroke intensity in muscle activation and produced sound level. While higher activation of the triceps brachii was observed for drum playing without a drumstick, no significant differences were found between the biceps brachii and sound level. This study demonstrated via surface electromyography data that greater muscle activation of the biceps brachii and triceps brachii does not occur with the use of drumsticks in drum playing. With the drum sound controlled, drum playing by hand can be an effective therapeutic intervention for the upper arm muscles. PMID:27419114

  13. Increase in passive muscle tension of the quadriceps muscle heads in jumping athletes with patellar tendinopathy.

    PubMed

    Zhang, Z J; Ng, G Y F; Lee, W C; Fu, S N

    2016-08-19

    To investigate the passive muscle tension of the quadriceps muscle heads in male athletes clinically diagnosed with patellar tendinopathy (PT) with those of healthy controls and explore the interplay between passive muscle tension and patellar tendon stiffness. Between November 2012 and December 2013, 66 male athletes (mean age of 21.1 ± 4.4 years) were examined using supersonic shear wave imaging technology. The passive tension of the vastus lateralis (VL) and rectus femoris (RF) muscles and patellar tendon stiffness were assessed. The shear elastic modulus of the VL muscle was increased by 26.5% (P < 0.001) in the subjects with PT when compared with the controls. Greater passive tension in the VL was associated with higher patellar tendon stiffness (r = 0.38; P = 0.001). The vastus lateralis muscle of the quadriceps shows increase in passive muscle tension in jumping athletes with patellar tendinopathy. These findings suggest that increase in muscle tension is not similar in the individual muscles of the quadriceps muscle. Traditional stretching of the whole quadriceps muscle might not be targeted to the tight muscle heads.

  14. Abnormalities of the long head of the biceps tendon of the shoulder: MR imaging findings.

    PubMed

    Tuckman, G A

    1994-11-01

    The normal anatomy of the long head of the biceps tendon of the shoulder has been described in detail [1]. Descriptions of different pathologic processes affecting this structure also have been published [1-3] but have been incomplete, showing only a limited variety of abnormalities. In this article, abnormalities of the long head of the biceps tendon seen on MR images are illustrated in greater variety and detail. Recognizing abnormalities of the biceps tendon is important because they are a common source of shoulder pain both alone and in combination with abnormalities of the rotator cuff, labrum, and other structures. Because incomplete diagnosis can lead to treatment failure, it is important to recognize less common imaging manifestations of common entities.

  15. Can self-ordering scalar fields explain the BICEP2 B-mode signal?

    SciTech Connect

    Durrer, Ruth; Figueroa, Daniel G.; Kunz, Martin E-mail: daniel.figueroa@unige.ch

    2014-08-01

    We show that self-ordering scalar fields (SOSF), i.e. non-topological cosmic defects arising after a global phase transition, cannot explain the B-mode signal recently announced by BICEP2. We compute the full C{sub ℓ}{sup B} angular power spectrum of B-modes due to vector and tensor perturbations of SOSF, modeled in the large N limit of a spontaneously broken global O(N) symmetry. We conclude that the low ℓ multipoles detected by BICEP2 cannot be due mainly to SOSF, since they have the wrong spectrum at low multipoles. As a byproduct we derive the first cosmological constraints on this model, showing that the BICEP2 B-mode polarization data admits at most a 2-3% contribution from SOSF in the temperature anisotropies, similar to (but somewhat tighter than) the recently studied case of cosmic strings.

  16. Tendinopathy of the tendon of the long head of the biceps.

    PubMed

    Longo, Umile Giuseppe; Loppini, Mattia; Marineo, Gianluca; Khan, Wasim S; Maffulli, Nicola; Denaro, Vincenzo

    2011-12-01

    Pathologies of tendon of the long head of the biceps (LHB) are an important cause of shoulder pain. They include tendinopathy, rupture, superior labrum anterior and posterior lesions, pulley tears, and tendon instability. Conservative management of symptomatic LHB tendinopathy is commonly accepted as the first-line treatment. It consists of rest, nonsteroidal anti-inflammatory drugs, corticosteroid injections, and physical therapy. Biceps tenotomy and tenodesis are the most common surgical procedures to manage both isolated LHB pathology and biceps-glenoid complex tears combined with rotator cuff tears. However, controversy persists about the superiority of one of them because there is no evidence of significant differences in functional scores or patient satisfaction between the 2 techniques. This article provides an overview on biomechanical function of the LHB and current strategies for treatment of LHB disorders.

  17. A comparison of physical examinations with musculoskeletal ultrasound in the diagnosis of biceps long head tendinitis.

    PubMed

    Chen, Hung-Sheng; Lin, Shu-Hsien; Hsu, Yen-Hsia; Chen, Shih-Ching; Kang, Jiunn-Horng

    2011-09-01

    Provocative tests are useful in diagnosing biceps tendon tendinitis. This is the first study to establish the reliability of these tests by comparing the resuts with musculoskeletal ultrasound (US) findings. This study examined 125 patients (69 women and 56 men) and 143 shoulders with shoulder pain. Yergason's test, Speed's test and a bicipital groove tenderness test were performed and musculoskeletal US findings were used as standard reference. Biceps tendon tendinitis was diagnosed with US in 39.1% of the patients and, of those, 55.3% had coexisting rotator cuff injury. The sensitivity and specificity of Yergason's test were 32% and 78%, respectively. The sensitivity and specificity of Speed's test were 63% and 58%, respectively. In conclusion, all three tests are limited by poor sensitivity. US can be an image modality choice in diagnosing biceps pathology.

  18. Effect of vitamin D status improvement with 25-hydroxycholecalciferol on skeletal muscle growth characteristics and satellite cell activity in broiler chickens.

    PubMed

    Hutton, K C; Vaughn, M A; Litta, G; Turner, B J; Starkey, J D

    2014-08-01

    Skeletal muscle satellite cells (SC) play a critical role in the hypertrophic growth of postnatal muscle. Increases in breast meat yield have been consistently observed in broiler chickens fed 25-hydroxycholecalciferol (25OHD3), but it is unclear whether this effect is mediated by SC. Thus, our objective was to determine the effect of vitamin D status improvement by replacing the majority of dietary vitamin D3 (D3) with 25OHD3 on SC activity and muscle growth characteristics in the pectoralis major (PM) and the biceps femoris (BF) muscles. Day-old, male Ross 708 broiler chickens (n = 150) were fed 1 of 2 corn and soybean meal-based diets for 49 d. The control diet (CTL) contained 5,000 IU D3 per kg of diet and the experimental diet (25OHD3) contained 2,240 IU D3 per kg of diet + 2,760 IU 25OHD3 per kg of diet. Ten birds per treatment were harvested every 7 d. Two hours before harvest, birds were injected intraperitoneally with 5'-bromo-2'deoxyuridine (BrdU) to label mitotically active cells. Blood was collected from each bird at harvest to measure circulating concentrations of 25OHD3, a marker of vitamin D status. The PM and BF muscles were weighed and processed for cryohistological determination of skeletal muscle fiber cross-sectional area, enumeration of Myf-5+ and Pax7+ SC, and mitotically active (BrdU+) SC using immunofluorescence microscopy. Circulating 25OHD3 concentrations were greater in 25OHD3-fed birds on d 7, 14, 21, 28, 35, 42, and 49 when compared with CTL (P < 0.001). Growth performance and feed efficiency did not differ among dietary treatments (P > 0.10). Improved vitamin D status as a result of feeding 25OHD3 increased the number of mitotically active (Pax7+;BrdU+) SC (P = 0.01) and tended to increase the density of Pax7+ SC (P = 0.07) in the PM muscles of broilers on d 21 and 35, respectively. Broiler chickens fed 25OHD3 also tended to have greater Myf-5+ SC density (P = 0.09) on d 14, greater total nuclear density (P = 0.05) on d 28, and a

  19. Tenotomy versus Tenodesis in the treatment of the long head of biceps brachii tendon lesions

    PubMed Central

    2012-01-01

    Background The superiority of tenotomy vs. tenodesis for surgery on lesions of the long head of the biceps brachii tendon is still under debate. Indeed, high-quality evidence is lacking, mainly because of methodological problems, such as retrospective design, population sample size or lack of patient randomization. Methods/Design The study will be a two-center, double-blind, randomized, controlled trial to compare patients treated with biceps tenotomy or tenodesis for lesions of the long head of the biceps brachii tendon over a 2-year follow-up period. The study participants will be 128 adults with biceps brachii tendinopathy and supraspinatus tendon tears. The primary end point will be the postoperative difference in the Constant-Murley score (CMS) between the 2 groups at the two-year follow-up. A comparison of the mean improvement with standard age- and gender-related CMS will be performed. The secondary end point will be evaluation of the postoperative general health of patients, as evaluated with Short Form 36 (SF-36) scores. The number and severity of complications associated with use of the different surgical techniques will be assessed. Discussion This study will be the first randomized and appropriately powered clinical trial to directly compare tenotomy and biceps tenodesis. The results of this study will help to establish clinical practice guidelines for patients suffering from lesions of the long head of the biceps brachii tendon, providing important information to patients and health care providers about the possible complications, outcome predictors and effectiveness of the targeted interventions. Trial Registration Current Controlled Trials ISRCTN38839558 PMID:23088416

  20. Arthroscopic tenodesis through positioning portals to treat proximal lesions of the biceps tendon.

    PubMed

    Shen, Ji; Gao, Qing-feng; Zhang, Yao; He, Yao-hua

    2014-12-01

    Arthroscopic biceps tenodesis is a good choice for treating proximal lesions of the biceps tendon. However, there are few descriptions of the surgical approach. We introduce a technique for proximal biceps tenodesis using positioning portals and placing suture anchors. Our patients had a minimum of 12 months of follow-up. Between January 2010 and June 2012, a total of 49 patients (21 men, 28 women) underwent arthroscopic biceps tenodesis. The pathology was mainly associated with proximal lesions of the biceps tendon, with the diagnosis confirmed in all patients. Patients were evaluated preoperatively and then up to and including the final follow-up. Their pain and conditions were assessed using the Constant, American Shoulder and Elbow Surgeons (ASES), and University of California at Los Angeles (UCLA) scores for pain; range of active forward flexion; and active range of motion. All data were analyzed statistically. All patients were operated on successfully. They achieved good healing during the follow-up (mean 14 months; range 12-34 months). Before surgery the ASES, Constant, and UCLA scores were 17.0, 39.4, and 15.4, respectively. After surgery they were 33.6, 89.1, and 31.2, respectively. The scores had significantly improved: ASES scores from 17.0 to 33.6 (P < 0.05); Constant scores from 39.4 to 89.1 (P < 0.05); UCLA scores from 15.4 to 31.2 (P < 0.05). Arthroscopic tenodesis through positioning portals to treat proximal lesions of the biceps tendon produces satisfactory clinical outcomes. This technique is convenient and safe.

  1. “ROCAMBOLE-LIKE” BICEPS TENODESIS: TECHNIQUE AND RESULTS

    PubMed Central

    Godinho, Glaydson Gomes; Mesquita, Fabrício Augusto Silva; França, Flávio de Oliveira; Freitas, José Márcio Alves

    2015-01-01

    Objective: To present a new technique for bicipital tenodesis and its results: accomplished partially via arthroscopy and grounded in concepts of the normal and pathological anatomy of the tendon of the biceps long head. It is based on the predisposition of this tendon towards becoming attached to the intertubercular sulcus after rupture or tenotomy (auto-tenodesis). Methods: Evaluations were conducted on 63 patients (63 shoulders), aged from 32 to 77 years (average 55), consisting of 32 females (51%) and 31 males (49%). Thirty-five of the patients (55.6%) were over 60 years of age and 28 patients (44.4%) were under 60 years of age. Eighteen were sports participants (28.6%). Fourteen had injuries associated with the subscapularis (22.2%). The average follow up was 43 months (ranging from 12 to 74 months). The right shoulder accounted for 48 cases (76.2%), of which one was a left-handed individual and 47 were right-handed. The left shoulder accounted for 15 (23%) of the patients, of whom two were left-handed and 13 were right-handed. There were no bilateral occurrences. The statistical analysis were done using SPSS version 18. Pearson's chi-square test and continuity corrections were used to investigate the statistical significance of associations between variables. Associations were taken to be statistically significant when p was less than 0.05. Results: Residual Popeye deformity was perceived by seven patients (11.1%); it was only observed by the examiner in 15 cases (23.8%); and neither the patient nor the examiner observed it in 41 cases (65%). There were no statistically valid influences from age, participation in contact or throwing sports, subscapularis tendon-associated injury or Popeye deformity. Fifty-eight patients (92.06%) were satisfied, two patients were dissatisfied (3.17%) and three patients were indifferent (4.76%). Conclusion: The technique presented high patient satisfaction rates (92.06%) and residual deformity was perceived by 11.1% of the

  2. Spontaneous resorption of calcification at the long head of the biceps tendon

    PubMed Central

    Amri, Adriansyah; Nakai, Sho; Hara, Michiharu; Yamanaka, Issei; Hamawaki, Jun-ichi

    2015-01-01

    Calcific tendinitis of the long head of the biceps tendon is a rare cause of shoulder pain. Calcium deposits are often spontaneously resorbed or reduced in size in the rotator cuff tendons, which represent the most common sites of calcific tendinitis around the shoulder. To our knowledge, no case of spontaneous resorption of calcification in the long head of the biceps tendon has been reported in the literature. Here, we report one such case and describe its successful treatment using a conservative approach. PMID:27582978

  3. Calcific tendinitis of the biceps-labral complex: a rare cause of acute shoulder pain.

    PubMed

    Ji, Jong-Hun; Shafi, Mohamed; Kim, Weon-Yoo

    2008-06-01

    Calcific tendinitis most commonly affects the rotator cuff and has not been previously reported affecting the biceps-labral complex. We report a case of calcific tendinitis of the biceps-labral complex attachment, a rare cause of acute, severe shoulder pain. Clinically, it can be misdiagnosed as supraspinatus tendinitis or septic arthritis of the shoulder joint. Non-operative treatment failed to resolve the symptoms. Arthroscopic debridement of the calcific deposit resulted in resolution of symptoms. Knowledge of this clinical condition and its imaging features is crucial for a correct diagnosis of this uncommon cause of shoulder pain.

  4. Effectiveness of roundhouse kick in elite Taekwondo athletes.

    PubMed

    Thibordee, Sutima; Prasartwuth, Orawan

    2014-06-01

    The roundhouse kick is a powerful attack in Taekwondo. Most athletes intently perform this kick for scoring in competition. Therefore, kinematic and kinetic analyzes of this kick were the topics of interest; however, they were separately investigated and rarely recorded for impact force. Our objectives were to investigate knee and ankle joint kinematics and electromyographic (EMG) activity of leg muscle and compare them between high-impact (HI) and low-impact (LO) kicks. Sixteen male black-belt Taekwondo athletes performed five roundhouse kicks at their maximal effort. Electrogoniometer sensors measured angular motions of ankle and knee joints. Surface EMG activities were recorded for tibialis anterior, gastrocnemius medialis, rectus femoris, and biceps femoris muscles. Based on maximal impact forces, the athletes were classified into HI and LO groups. All athletes in both groups showed greater activation of rectus femoris than other muscles. The HI group only showed significantly less plantarflexion angles than the LO group during preimpact and impact phases (P<0.05). During the impact phase, the HI group demonstrated significantly greater biceps femoris activation than the LO group (P<0.05). In conclusion, rectus femoris activation could predominantly contribute to the powerful roundhouse kicks. Moreover, high biceps femoris co-activation and optimal angle of ankle plantarflexion of about 35° could help achieve the high impact force.

  5. DOES RECTUS FEMORIS TRANSFER INCREASE KNEE FLEXION DURING STANCE PHASE IN CEREBRAL PALSY?

    PubMed Central

    de Morais, Mauro César; Blumetti, Francesco Camara; Kawamura, Cátia Miyuki; Lopes, José Augusto Fernandes; Neves, Daniella Lins; Cardoso, Michelle de Oliveira

    2016-01-01

    ABSTRACT Objective: To evaluate whether distal rectus femoris transfer (DRFT) is related to postoperative increase of knee flexion during the stance phase in cerebral palsy (CP). Methods: The inclusion criteria were Gross Motor Function Classification System (GMFCS) levels I-III, kinematic criteria for stiff-knee gait at baseline, and individuals who underwent orthopaedic surgery and had gait analyses performed before and after intervention. The patients included were divided into the following two groups: NO-DRFT (133 patients), which included patients who underwent orthopaedic surgery without DRFT, and DRFT (83 patients), which included patients who underwent orthopaedic surgery that included DRFT. The primary outcome was to evaluate in each group if minimum knee flexion in stance phase (FMJFA) changed after treatment. Results: The mean FMJFA increased from 13.19° to 16.74° (p=0.003) and from 10.60° to 14.80° (p=0.001) in Groups NO-DRFT and DRFT, respectively. The post-operative FMJFA was similar between groups NO-DRFT and DRFT (p=0.534). The increase of FMJFA during the second exam (from 13.01° to 22.51°) was higher among the GMFCS III patients in the DRFT group (p<0.001). Conclusion: In this study, DRFT did not generate additional increase of knee flexion during stance phase when compared to the control group. Level of Evidence III, Retrospective Comparative Study. PMID:26997910

  6. Age-related decrease of the phosphorus content in the ligamentum capitis femoris of monkeys.

    PubMed

    Tohno, Yoshiyuki; Tohno, Setsuko; Oishi, Takao; Minami, Takeshi; Khanpetch, Pongsak; Azuma, Cho; Quiggins, Ranida

    2014-10-01

    To elucidate compositional changes of the ligament with aging, the authors investigated age-related changes of elements in the ligamentum capitis femoris (LCF) of monkeys with a wide range of ages by direct chemical analysis. Used rhesus and Japanese monkeys consisted of 9 males and 22 females, ranging in age from newborn to 31 years (average age = 10.4 ± 10.9 years). After incineration with nitric acid and perchloric acid, element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that the P content decreased significantly in the LCFs of monkeys with aging, but other six element contents, Ca, S, Mg, Zn, Fe, and Na, did not change significantly with aging. Assuming that the P content indicated the active cell density and the S content indicated the protein amount, an age-related change of the mass ratio of P/S was examined in the LCFs. The mass ratio of P/S decreased significantly in the LCFs in childhood. Regarding the relationships among elements, significant direct correlations were found among the Ca, P, S, and Mg contents in the LCFs. It was suggested that the active cell density of the connective tissue cells might decrease significantly in the LCF in childhood.

  7. Agonist and Antagonist Muscle EMG Activity Pattern Changes with Skill Acquisition.

    ERIC Educational Resources Information Center

    Engelhorn, Richard

    1983-01-01

    Using electromyography (EMG), researchers studied changes in the control of biceps and triceps brachii muscles that occurred as women college students learned two elbow flexion tasks. Data on EMG activity, angular kinematics, training, and angular displacement were analyzed. (Author/PP)

  8. Signaling Pathways Related to Protein Synthesis and Amino Acid Concentration in Pig Skeletal Muscles Depend on the Dietary Protein Level, Genotype and Developmental Stages

    PubMed Central

    Liu, Yingying; Li, Fengna; Kong, Xiangfeng; Tan, Bie; Li, Yinghui; Duan, Yehui; Blachier, François; Hu, Chien-An A.; Yin, Yulong

    2015-01-01

    Muscle growth is regulated by the homeostatic balance of the biosynthesis and degradation of muscle proteins. To elucidate the molecular interactions among diet, pig genotype, and physiological stage, we examined the effect of dietary protein concentration, pig genotype, and physiological stages on amino acid (AA) pools, protein deposition, and related signaling pathways in different types of skeletal muscles. The study used 48 Landrace pigs and 48 pure-bred Bama mini-pigs assigned to each of 2 dietary treatments: lower/GB (Chinese conventional diet)- or higher/NRC (National Research Council)-protein diet. Diets were fed from 5 weeks of age to respective market weights of each genotype. Samples of biceps femoris muscle (BFM, type I) and longissimus dorsi muscle (LDM, type II) were collected at nursery, growing, and finishing phases according to the physiological stage of each genotype, to determine the AA concentrations, mRNA levels for growth-related genes in muscles, and protein abundances of mechanistic target of rapamycin (mTOR) signaling pathway. Our data showed that the concentrations of most AAs in LDM and BFM of pigs increased (P<0.05) gradually with increasing age. Bama mini-pigs had generally higher (P<0.05) muscle concentrations of flavor-related AA, including Met, Phe, Tyr, Pro, and Ser, compared with Landrace pigs. The mRNA levels for myogenic determining factor, myogenin, myocyte-specific enhancer binding factor 2 A, and myostatin of Bama mini-pigs were higher (P<0.05) than those of Landrace pigs, while total and phosphorylated protein levels for protein kinase B, mTOR, and p70 ribosomal protein S6 kinases (p70S6K), and ratios of p-mTOR/mTOR, p-AKT/AKT, and p-p70S6K/p70S6K were lower (P<0.05). There was a significant pig genotype-dependent effect of dietary protein on the levels for mTOR and p70S6K. When compared with the higher protein-NRC diet, the lower protein-GB diet increased (P<0.05) the levels for mTOR and p70S6K in Bama mini-pigs, but

  9. GLENOHUMERAL MUSCLE ACTIVATION DURING PROVOCATIVE TESTS DESIGNED TO DIAGNOSE SUPERIOR LABRUM ANTERIOR-POSTERIOR LESIONS

    PubMed Central

    Wood, Vanessa J.C.; Sabick, Michelle B.; Pfeiffer, Ron P.; Kuhlman, Seth M.; Christensen, Jason H.; Curtin, Michael J.

    2012-01-01

    Background Despite considerable medical advances, arthroscopy remains the only definitive means of Superior Labrum Anterior-Posterior (SLAP) lesion diagnosis. Natural shoulder anatomic variants limit the reliability of radiographic findings and clinical evaluations are not consistent. Accurate clinical diagnostic techniques would be advantageous due to the invasiveness, patient risk, and financial cost associated with arthroscopy. Purpose The purpose was to examine the behavior of the joint stabilizing muscles in provocative tests for SLAP lesions. Electromyography was used to characterize the muscle behavior, with particular interest in the long head biceps brachii (LHBB), as activation of the long head and subsequent tension in the biceps tendon should, based on related research, elicit labral symptoms in SLAP lesion patients. Study Design Controlled Laboratory Study Methods Volunteers (N=21) without a history of shoulder pathology were recruited. The tests analyzed were Active Compression, Speed's, Pronated Load, Biceps I, Biceps II, Resisted Supination External Rotation, and Yergason's. Tests were performed with a dynamometer to improve reproducibility. Muscle activity was recorded for the long and short heads of the biceps brachii, anterior deltoid, pectoralis major, latissimus dorsi, infraspinatus, and supraspinatus. Muscle behavior for each test was characterized by peak activation and proportion of muscle activity. Results Speed's, Active Compression Palm-Up, Bicep I and Bicep II, produced higher long head activations. Resisted Supination External Rotation, Bicep I, Bicep II, and Yergason's, produced a higher LHBB proportion. Conclusion Bicep I, and Bicep II elicited promising long head behavior (high activation and selectivity). Speed's and Active Compression Palm-Up elicited higher activation of the LHBB , and Resisted Supination and Yergason's elicited selective LHBB activity. These top performing tests utilize a unique range of test variables that may

  10. Optimising muscle parameters in musculoskeletal models using Monte Carlo simulation.

    PubMed

    Reed, Erik B; Hanson, Andrea M; Cavanagh, Peter R

    2015-01-01

    The use of musculoskeletal simulation software has become a useful tool for modelling joint and muscle forces during human activity, including in reduced gravity because direct experimentation is difficult. Knowledge of muscle and joint loads can better inform the design of exercise protocols and exercise countermeasure equipment. In this study, the LifeModeler™ (San Clemente, CA, USA) biomechanics simulation software was used to model a squat exercise. The initial model using default parameters yielded physiologically reasonable hip-joint forces but no activation was predicted in some large muscles such as rectus femoris, which have been shown to be active in 1-g performance of the activity. Parametric testing was conducted using Monte Carlo methods and combinatorial reduction to find a muscle parameter set that more closely matched physiologically observed activation patterns during the squat exercise. The rectus femoris was predicted to peak at 60.1% activation in the same test case compared to 19.2% activation using default parameters. These results indicate the critical role that muscle parameters play in joint force estimation and the need for exploration of the solution space to achieve physiologically realistic muscle activation.

  11. Comparison of maximum voluntary isometric contraction of the biceps on various posture and respiration conditions for normalization of electromyography data

    PubMed Central

    Lee, Sang-Yeol; Jo, Marg-Eun

    2016-01-01

    [Purpose] Maximum voluntary isometric contraction can increase the reliability of electromyography data by controlling respiration; however, many studies that use normalization of electromyography data fail to account for this. This study aims to check changes in maximum voluntary isometric contraction based on changes in posture and respiration conditions. [Subjects and Methods] Twenty-two healthy volunteers were included in this study. Using 22 healthy subjects, MVIC of the biceps brachii muscle was measured in three respiration conditions: (1) Maximum voluntary isometric contraction during inspiration after maximal expiration, (2) Maximum voluntary isometric contraction during expiration after maximal inspiration and (3) Maximum voluntary isometric contraction during the Valsalva maneuver. The subjects were in tested in standing and supine postures under all three respiration conditions. [Results] A significant difference was observed in the standing and supine postures based on the respiration condition. A significant difference was observed in the maximum voluntary isometric contraction during inspiration after maximal expiration and maximum voluntary isometric contraction during the Valsalva maneuver conditions when the subjects were in the supine posture. [Conclusion] It is necessary to apply the same respiration condition and the same posture to each subject when measuring Maximum voluntary isometric contraction for the normalization of electromyography data. PMID:27942110

  12. Simulating the activation, contraction and movement of skeletal muscles using the bidomain model.

    PubMed

    Lopez Rincon, A; Cantu, C; Soto, R; Shimoda, S

    2016-08-01

    A simulation of the muscle activation, contraction and movement is here presented. This system was developed based on the Bidomain mathematical model of the electrical propagation in muscles. This study shows an electrical stimuli input to a muscle and how this behave. The comparison between healthy subject and patient with muscle activation impairment is depicted, depending on whether the signal reaches a threshold. A 3D model of a bicep muscle and a forearm bone connected was constructed using OpenGL. This platform could be used for development of controllers for biomechatronic systems in future works. This kind of bioinspired model could be used for a better understanding of the neuromotor system.

  13. Your Muscles

    MedlinePlus

    ... Room? What Happens in the Operating Room? Your Muscles KidsHealth > For Kids > Your Muscles A A A ... and skeletal (say: SKEL-uh-tul) muscle. Smooth Muscles Smooth muscles — sometimes also called involuntary muscles — are ...

  14. Ultrafast imaging of in vivo muscle contraction using ultrasound

    NASA Astrophysics Data System (ADS)

    Deffieux, Thomas; Gennisson, Jean-Luc; Tanter, Mickaël; Fink, Mathias; Nordez, Antoine

    2006-10-01

    In this letter, an innovative way of imaging transient and local shear vibrations of an in vivo contracting muscle is proposed. The principle is to use an ultrafast ultrasound scanner (up to 5000framess-1) able to follow with a submillimeter resolution the motion of the muscle tissue in a two dimensional plane. This ultrafast echographic imaging technique leads to both local and transient in vivo studies of the contraction of a muscle as reported by these first experiments done on the biceps brachii.

  15. Clinical and Sonographic Evaluation of Bicortical Button for Proximal Biceps Tenodesis.

    PubMed

    Meadows, James R; Diesselhorst, Matthew M; Finnoff, Jonathan T; Swanson, Britta L; Swanson, Kyle E

    2016-01-01

    Use of a cortical button for proximal biceps tenodesis has demonstrated strength comparable to that of other types of fixation in biomechanical models, but few studies have evaluated the clinical outcome of such fixation. In the study reported here, 18 patients who underwent open subpectoral biceps tenodesis with a bicortical button were assessed, at minimum 12-month follow-up, with the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, a pain scale, physical examination, biceps supination strength testing, and ultrasonographic evaluation (to determine tenodesis integrity and proximity of the button to the axillary nerve). No patient had symptoms of axillary nerve damage, clinical deformity, or tenodesis failure. Mean DASH score was 15.15 (scale range: 0, none to 100, extreme difficulty), and mean pain score was 12.6 (scale range: 0, none to 100, worst pain). Seventy-eight percent of patients had no bicipital groove tenderness, 89% had full elbow range of motion, and 94% had full shoulder range of motion. Mean forearm supination strength of the operated arm (125.04 lb) was significantly (P = .01) less than that of the nonoperated arm (134.39 lb). Mean (SD) distance from button to posterior circumflex humeral artery was 18.17 (9.0) mm. The study results suggest that subpectoral biceps tenodesis with a bicortical button is a safe, stable procedure that results in excellent functional outcomes.

  16. Content Analysis Schedule for Bilingual Education Programs: BICEP Intercambio de la Cultura.

    ERIC Educational Resources Information Center

    Shore, Marietta Saravia; Nafus, Charles

    This content analysis schedule for BICEP Intercambio de la Cultura (San Bernardino, California), presents information on the history, funding, and scope of the project. Included are sociolinguistic process variables such as the native and dominant languages of students and their interaction. Information is provided on staff selection and the…

  17. Bilateral Superior Labrum Anterior to Posterior (SLAP) Tears With Abnormal Anatomy of Biceps Tendon.

    PubMed

    Morris, Dan; Guettler, Joseph; Morris, Sean

    2015-08-01

    There have been several descriptions of variant anatomy of the long head of the biceps tendon (LHBT). A recent literature review identified 8 cases of anomalous intracapsular attachment of the LHBT. In this report, we discuss a distinctive case of a young athlete who presented with symptoms consistent with bilateral superior labrum anterior to posterior (SLAP) tears that were unresponsive to conservative measures. Magnetic resonance imaging and arthroscopic findings of this patient confirmed that the patient had type II SLAP tears, a Buford complex anteriorly, and perhaps most important, confluence of the biceps tendon itself to the undersurface of the capsule within the rotator interval. Our case proposes that anomalous insertion of the LHBT, as well as other labral and biceps anchor variations, are not always a benign finding at the time of arthroscopy. In this particular case, the tethering of the biceps tendon to the capsule is thought to have increased stress on the superior labrum and contributed to the development of the bilateral symptomatic type II SLAP tears that were identified and treated in this young athlete.

  18. Clinical Outcomes and Complications of Cortical Button Distal Biceps Repair: A Systematic Review of the Literature

    PubMed Central

    Pantazis, Konstantinos

    2016-01-01

    Objectives. The purpose of the present study was to investigate the clinical outcomes and complications of the cortical button distal biceps fixation method. Material and Methods. All methods followed the PRISMA guidelines. Included studies had to describe clinical outcomes and complications after acute distal biceps repair with cortical button fixation. Eligibility criteria also included English language, more than 5 cases with minimum follow-up of 6 months, and preferably usage of at least one relevant clinical score (MEPS, ASES, and/or DASH) for final outcome. A loss of at least 30° in motion—flexion, extension, pronation, or supination—and a loss of at least 30% of strength were considered an unsatisfactory result. Results. The review identified 7 articles including 105 patients (mean age 43.6 years) with 106 acute distal biceps ruptures. Mean follow-up was 26.3 months. Functional outcome of ROM regarding flexion/extension and pronation/supination was satisfactory in 94 (89.5%) and 86 (82%) patients in respect. Averaged flexion and supination strength had been reported in 6/7 studies (97 patients) and were satisfactory in 82.4% of them. The most common complication was transient nerve palsy (14.2%). The overall reoperation rate was 4.8% (5/105 cases). Conclusion. Cortical button fixation for acute distal biceps repair is a reproducible operation with good clinical results. Most of the complications can be avoided with appropriate surgical technique. PMID:27525303

  19. Acute compartment syndrome of the forearm caused by calcific tendinitis of the distal biceps.

    PubMed

    Garayoa, Santiago Amillo; Romero-Muñoz, Luis M; Pons-Villanueva, Juan

    2010-12-01

    Acute compartment syndrome of the forearm requires immediate treatment to avoid damage of the soft tissues and a poor functional outcome for the forearm. Muscular and bone lesions are the main causes of acute compartment syndromes. We report a case of acute compartment syndrome of the forearm caused by a calcific tendinitis of the distal biceps.

  20. Eccentric muscle challenge shows osteopontin polymorphism modulation of muscle damage.

    PubMed

    Barfield, Whitney L; Uaesoontrachoon, Kitipong; Wu, Chung-Sheih; Lin, Stephen; Chen, Yue; Wang, Paul C; Kanaan, Yasmine; Bond, Vernon; Hoffman, Eric P

    2014-08-01

    A promoter polymorphism of the osteopontin (OPN) gene (rs28357094) has been associated with multiple inflammatory states, severity of Duchenne muscular dystrophy (DMD) and muscle size in healthy young adults. We sought to define the mechanism of action of the polymorphism, using allele-specific in vitro reporter assays in muscle cells, and a genotype-stratified intervention in healthy controls. In vitro reporter constructs showed the G allele to respond to estrogen treatment, whereas the T allele showed no transcriptional response. Young adult volunteers (n = 187) were enrolled into a baseline study, and subjects with specific rs28357094 genotypes enrolled into an eccentric muscle challenge intervention [n = 3 TT; n = 3 GG/GT (dominant inheritance model)]. Female volunteers carrying the G allele showed significantly greater inflammation and increased muscle volume change as determined by magnetic resonance imaging T1- and T2-weighted images after eccentric challenge, as well as greater decrement in biceps muscle force. Our data suggest a model where the G allele enables enhanced activities of upstream enhancer elements due to loss of Sp1 binding at the polymorphic site. This results in significantly greater expression of the pro-inflammatory OPN cytokine during tissue remodeling in response to challenge in G allele carriers, promoting muscle hypertrophy in normal females, but increased damage in DMD patients.

  1. Effect of Different Forefoot and Heel Support Surfaces on the Activities of the RF and HAM Muscles during the Sit-to-stand Task while Wearing High-heel Shoes.

    PubMed

    Yoo, Won-Gyu

    2014-10-01

    [Purpose] The purpose of this study was to show the effect of different forefoot and heel support surfaces on the activities of the rectus femoris and medial hamstring muscles during the sit-to-stand task while wearing high-heel shoes. [Subjects] Fifteen female subjects were recruited. [Methods] The muscle activities of the rectus femoris and hamstring muscles were recorded using an MP150 system during the sit-to-stand task while wearing various high-heeled shoes. [Results] The activities of the rectus femoris and medial hamstring muscles significantly decreased when subjects wore condition 1 shoes compared with when they wore condition 2, 3 or 4 high-heeled shoes. The activities of the rectus femoris and medial hamstring muscles significantly decreased when subjects wore condition 2 high-heeled shoes compared with condition 3 or 4 high-heeled shoes. [Conclusion] The results can be interpreted as indicating that the size of the forefoot supporting surface can influence the lower extremity muscles of women wearing high-heeled shoes more than the size of the heel supporting surface.

  2. The characterization of decellularized human skeletal muscle as a blueprint for mimetic scaffolds.

    PubMed

    Wilson, Klaire; Terlouw, Abby; Roberts, Kevin; Wolchok, Jeffrey C

    2016-08-01

    The use of decellularized skeletal muscle (DSM) as a cell substrate and scaffold for the repair of volumetric muscle loss injuries has shown therapeutic promise. The performance of DSM materials motivated our interest in exploring the chemical and physical properties of this promising material. We suggest that these properties could serve as a blueprint for the development of next generation engineered materials with DSM mimetic properties. In this study, whole human lower limb rectus femoris (n = 10) and upper limb supraspinatus muscle samples (n = 10) were collected from both male and female tissue donors. Skeletal muscle samples were decellularized and nine property values, capturing key compositional, architectural, and mechanical properties, were measured and statistically analyzed. Mean values for each property were determined across muscle types and sexes. Additionally, the influence of muscle type (upper vs lower limb) and donor sex (male vs female) on each of the DSM material properties was examined. The data suggests that DSM materials prepared from lower limb rectus femoris samples have an increased modulus and contain a higher collagen content then upper limb supraspinatus muscles. Specifically, lower limb rectus femoris DSM material modulus and collagen content was approximately twice that of lower limb supraspinatus DSM samples. While muscle type did show some influence on material properties, we did not find significant trends related to sex. The material properties reported herein may be used as a blueprint for the data-driven design of next generation engineered scaffolds with muscle mimetic properties, as well as inputs for computational and physical models of skeletal muscle.

  3. Relation between systemic inflammatory markers, peripheral muscle mass, and strength in limb muscles in stable COPD patients

    PubMed Central

    Ferrari, Renata; Caram, Laura MO; Faganello, Marcia M; Sanchez, Fernanda F; Tanni, Suzana E; Godoy, Irma

    2015-01-01

    The aim of this study was to investigate the association between systemic inflammatory mediators and peripheral muscle mass and strength in COPD patients. Fifty-five patients (69% male; age: 64±9 years) with mild/very severe COPD (defined as forced expiratory volume in the first second [FEV1] =54%±23%) were evaluated. We evaluated serum concentrations of IL-8, CRP, and TNF-α. Peripheral muscle mass was evaluated by computerized tomography (CT); midthigh cross-sectional muscle area (MTCSA) and midarm cross-sectional muscle area (MACSA) were obtained. Quadriceps, triceps, and biceps strength were assessed through the determination of the one-repetition maximum. The multiple regression results, adjusted for age, sex, and FEV1%, showed positive significant association between MTCSA and leg extension (0.35 [0.16, 0.55]; P=0.001), between MACSA and triceps pulley (0.45 [0.31, 0.58]; P=0.001), and between MACSA and biceps curl (0.34 [0.22, 0.47]; P=0.001). Plasma TNF-α was negatively associated with leg extension (−3.09 [−5.99, −0.18]; P=0.04) and triceps pulley (−1.31 [−2.35, −0.28]; P=0.01), while plasma CRP presented negative association with biceps curl (−0.06 [−0.11, −0.01]; P=0.02). Our results showed negative association between peripheral muscle mass (evaluated by CT) and muscle strength and that systemic inflammation has a negative influence in the strength of specific groups of muscles in individuals with stable COPD. This is the first study showing association between systemic inflammatory markers and strength in upper limb muscles. PMID:26345641

  4. Relation between systemic inflammatory markers, peripheral muscle mass, and strength in limb muscles in stable COPD patients.

    PubMed

    Ferrari, Renata; Caram, Laura M O; Faganello, Marcia M; Sanchez, Fernanda F; Tanni, Suzana E; Godoy, Irma

    2015-01-01

    The aim of this study was to investigate the association between systemic inflammatory mediators and peripheral muscle mass and strength in COPD patients. Fifty-five patients (69% male; age: 64±9 years) with mild/very severe COPD (defined as forced expiratory volume in the first second [FEV1] =54%±23%) were evaluated. We evaluated serum concentrations of IL-8, CRP, and TNF-α. Peripheral muscle mass was evaluated by computerized tomography (CT); midthigh cross-sectional muscle area (MTCSA) and midarm cross-sectional muscle area (MACSA) were obtained. Quadriceps, triceps, and biceps strength were assessed through the determination of the one-repetition maximum. The multiple regression results, adjusted for age, sex, and FEV1%, showed positive significant association between MTCSA and leg extension (0.35 [0.16, 0.55]; P=0.001), between MACSA and triceps pulley (0.45 [0.31, 0.58]; P=0.001), and between MACSA and biceps curl (0.34 [0.22, 0.47]; P=0.001). Plasma TNF-α was negatively associated with leg extension (-3.09 [-5.99, -0.18]; P=0.04) and triceps pulley (-1.31 [-2.35, -0.28]; P=0.01), while plasma CRP presented negative association with biceps curl (-0.06 [-0.11, -0.01]; P=0.02). Our results showed negative association between peripheral muscle mass (evaluated by CT) and muscle strength and that systemic inflammation has a negative influence in the strength of specific groups of muscles in individuals with stable COPD. This is the first study showing association between systemic inflammatory markers and strength in upper limb muscles.

  5. Progressive Muscle Atrophy and Weakness After Treatment by Mantle Field Radiotherapy in Hodgkin Lymphoma Survivors

    SciTech Connect

    Leeuwen-Segarceanu, Elena M. van; Dorresteijn, Lucille D.A.; Pillen, Sigrid; Biesma, Douwe H.; Vogels, Oscar J.M.; Alfen, Nens van

    2012-02-01

    Purpose: To describe the damage to the muscles and propose a pathophysiologic mechanism for muscle atrophy and weakness after mantle field radiotherapy in Hodgkin lymphoma (HL) survivors. Methods and Materials: We examined 12 patients treated by mantle field radiotherapy between 1969 and 1998. Besides evaluation of their symptoms, the following tests were performed: dynamometry; ultrasound of the sternocleidomastoid, biceps, and antebrachial flexor muscles; and needle electromyography of the neck, deltoid, and ultrasonographically affected arm muscles. Results: Ten patients (83%) experienced neck complaints, mostly pain and muscle weakness. On clinical examination, neck flexors were more often affected than neck extensors. On ultrasound, the sternocleidomastoid was severely atrophic in 8 patients, but abnormal echo intensity was seen in only 3 patients. Electromyography of the neck muscles showed mostly myogenic changes, whereas the deltoid, biceps, and antebrachial flexor muscles seemed to have mostly neurogenic damage. Conclusions: Many patients previously treated by mantle field radiotherapy develop severe atrophy and weakness of the neck muscles. Neck muscles within the radiation field show mostly myogenic damage, and muscles outside the mantle field show mostly neurogenic damage. The discrepancy between echo intensity and atrophy suggests that muscle damage is most likely caused by an extrinsic factor such as progressive microvascular fibrosis. This is also presumed to cause damage to nerves within the radiated field, resulting in neurogenic damage of the deltoid and arm muscles.

  6. Mathematical modeling of the human knee joint

    SciTech Connect

    Ricafort, Juliet

    1996-05-01

    A model was developed to determine the forces exerted by several flexor and extensor muscles of the human knee under static conditions. The following muscles were studied: the gastrocnemius, biceps femoris, semitendinosus, semimembranosus, and the set of quadricep muscles. The tibia and fibula were each modeled as rigid bodies; muscles were modeled by their functional lines of action in space. Assumptions based on previous data were used to resolve the indeterminacy.

  7. Perfluoro-N-Butyl Iodide (PFBI): A 13-Week Nose-Only Inhalation Toxicity Study In Rats With A 4-Week Recovery Period

    DTIC Science & Technology

    2006-09-01

    between the upper incisor tooth and incisive papilla . The second section included the area between the incisive papilla and the first palatal ridge...with mainstem bronchi) X X X X lymph node (mediastinal and mesenteric) X X mammary gland X muscle (biceps femoris) X nasopharyngeal tissueb

  8. The biomechanics of running in athletes with previous hamstring injury: A case-control study.

    PubMed

    Daly, C; Persson, U McCarthy; Twycross-Lewis, R; Woledge, R C; Morrissey, D

    2016-04-01

    Hamstring injury is prevalent with persistently high reinjury rates. We aim to inform hamstring rehabilitation by exploring the electromyographic and kinematic characteristics of running in athletes with previous hamstring injury. Nine elite male Gaelic games athletes who had returned to sport after hamstring injury and eight closely matched controls sprinted while lower limb kinematics and muscle activity of the previously injured biceps femoris, bilateral gluteus maximus, lumbar erector spinae, rectus femoris, and external oblique were recorded. Intergroup comparisons of muscle activation ratios and kinematics were performed. Previously injured athletes demonstrated significantly reduced biceps femoris muscle activation ratios with respect to ipsilateral gluteus maximus (maximum difference -12.5%, P = 0.03), ipsilateral erector spinae (maximum difference -12.5%, P = 0.01), ipsilateral external oblique (maximum difference -23%, P = 0.01), and contralateral rectus femoris (maximum difference -22%, P = 0.02) in the late swing phase. We also detected sagittal asymmetry in hip flexion (maximum 8°, P = 0.01), pelvic tilt (maximum 4°, P = 0.02), and medial rotation of the knee (maximum 6°, P = 0.03) effectively putting the hamstrings in a lengthened position just before heel strike. Previous hamstring injury is associated with altered biceps femoris associated muscle activity and potentially injurious kinematics. These deficits should be considered and addressed during rehabilitation.

  9. The reliability of the FitroDyne as a measure of muscle power.

    PubMed

    Jennings, Courtney L; Viljoen, Wayne; Durandt, Justin; Lambert, Mike I

    2005-11-01

    The FitroDyne is a device that attaches to conventional resistance-training equipment to measure speed of movement, from which muscle power is calculated. The aim of this study was to quantify the repeatability of the measurement of muscle power with the FitroDyne during squat jump and biceps curl exercises. Thirty male subjects completed 3 trials, each consisting of 6 squat jumps and 6 biceps curls of increasing loads. Upper body and lower body maximum power was predicted from the force-velocity curves derived from the range of weights used for each trial. Maximum power measurements of a squat jump (range, 911- 1,673 W) and biceps curl (range, 45-110 W) had intraclass correlation coefficients (ICC) of R = 0.97 (95% CI, 0.95-0.98) and R = 0.97 (95% CI, 0.95-0.98), respectively. The limits of agreement for the squat jump and biceps curl trials were -17 +/- 96 W and 0.11 +/- 13.90 W, respectively. It may be concluded that muscle power can be measured with a high degree of reliability with the FitroDyne. The limits of agreement need to be considered when data are interpreted.

  10. Reproducibility of transcranial magnetic stimulation metrics in the study of proximal upper limb muscles

    PubMed Central

    Sankarasubramanian, Vishwanath; Roelle, Sarah; Bonnett, Corin E; Janini, Daniel; Varnerin, Nicole; Cunningham, David A; Sharma, Jennifer S; Potter-Baker, Kelsey A; Wang, Xiaofeng; Yue, Guang H; Plow, Ela B

    2015-01-01

    Objective Reproducibility of transcranial magnetic stimulation (TMS) metrics is essential in accurately tracking recovery and disease. However, majority of evidence pertains to reproducibility of metrics for distal upper limb muscles. We investigate for the first time, reliability of corticospinal physiology for a large proximal muscle-the biceps brachii and relate how varying statistical analyses can influence interpretations. Methods 14 young right-handed healthy participants completed two sessions assessing resting motor threshold (RMT), motor evoked potentials (MEPs), motor map and intra-cortical inhibition (ICI) from the left biceps brachii. Analyses included paired t-tests, Pearson's, intra-class (ICC) and concordance correlation coefficients (CCC) and Bland-Altman plots. Results Unlike paired t-tests, ICC, CCC and Pearson's were >0.6 indicating good reliability for RMTs, MEP intensities and locations of map; however values were <0.3 for MEP responses and ICI. Conclusions Corticospinal physiology, defining excitability and output in terms of intensity of the TMS device, and spatial loci are the most reliable metrics for the biceps. MEPs and variables based on MEPs are less reliable since biceps receives fewer cortico-motor-neuronal projections. Statistical tests of agreement and associations are more powerful reliability indices than inferential tests. Significance Reliable metrics of proximal muscles when translated to a larger number of participants would serve to sensitively track and prognosticate function in neurological disorders such as stroke where proximal recovery precedes distal. PMID:26111434

  11. Natural inflation: consistency with cosmic microwave background observations of Planck and BICEP2

    SciTech Connect

    Freese, Katherine; Kinney, William H. E-mail: whkinney@buffalo.edu

    2015-03-01

    Natural inflation is a good fit to all cosmic microwave background (CMB) data and may be the correct description of an early inflationary expansion of the Universe. The large angular scale CMB polarization experiment BICEP2 has announced a major discovery, which can be explained as the gravitational wave signature of inflation, at a level that matches predictions by natural inflation models. The natural inflation (NI) potential is theoretically exceptionally well motivated in that it is naturally flat due to shift symmetries, and in the simplest version takes the form V(φ) = Λ{sup 4} [1 ± cos(Nφ/f)]. A tensor-to-scalar ratio r > 0.1 as seen by BICEP2 requires the height of any inflationary potential to be comparable to the scale of grand unification and the width to be comparable to the Planck scale. The Cosine Natural Inflation model agrees with all cosmic microwave background measurements as long as f ≥ m{sub Pl} (where m{sub Pl} = 1.22 × 10{sup 19} GeV) and Λ ∼ m{sub GUT} ∼ 10{sup 16} GeV. This paper also discusses other variants of the natural inflation scenario: we show that axion monodromy with potential V∝ φ{sup 2/3} is inconsistent with the BICEP2 limits at the 95% confidence level, and low-scale inflation is strongly ruled out. Linear potentials V ∝ φ are inconsistent with the BICEP2 limit at the 95% confidence level, but are marginally consistent with a joint Planck/BICEP2 limit at 95%. We discuss the pseudo-Nambu Goldstone model proposed by Kinney and Mahanthappa as a concrete realization of low-scale inflation. While the low-scale limit of the model is inconsistent with the data, the large-field limit of the model is marginally consistent with BICEP2. All of the models considered predict negligible running of the scalar spectral index, and would be ruled out by a detection of running.

  12. Muscle motion and EMG activity in vibration treatment.

    PubMed

    Fratini, Antonio; La Gatta, Antonio; Bifulco, Paolo; Romano, Maria; Cesarelli, Mario

    2009-11-01

    The aim of this study is to highlight the relationship between muscle motion, generated by whole body vibration, and the correspondent electromyographic (EMG) activity and to suggest a new method to customize the stimulation frequency. Simultaneous recordings of EMG and tri-axial accelerations of quadriceps rectus femoris from fifteen subjects undergoing vibration treatments were collected. Vibrations were delivered via a sinusoidal oscillating platform at different frequencies (10-45 Hz). Muscle motion was estimated by processing the accelerometer data. Large EMG motion artifacts were removed using sharp notch filters centred at the vibration frequency and its superior harmonics. EMG-RMS values were computed and analyzed before and after artifact suppression to assess muscular activity. Muscles acceleration amplitude increased with frequency. Muscle displacements revealed a mechanical resonant-like behaviour of the muscle. Resonance frequencies and dumping factors depended on subject. Moreover, RMS of artifact-free EMG was found well correlated (R(2)=0.82) to the actual muscle displacement, while the maximum of the EMG response was found related to the mechanical resonance frequency of muscle. Results showed that maximum muscular activity was found in correspondence to the mechanical resonance of the muscle itself. Assuming the hypothesis that muscle activation is proportional to muscle displacement, treatment optimization (i.e. to choose the best stimulation frequency) could be obtained by simply monitoring local acceleration (resonance), leading to a more effective muscle stimulation. Motion artifact produced an overestimation of muscle activity, therefore its removal was essential.

  13. Electromyographic study of polysynaptic responses from muscles not supplied by the stimulated nerve: preliminary report.

    PubMed

    Vernea, J

    1978-01-01

    15 subjects with normal neurological examinations, 7 hemiplegic patients, 5 patients with dementia and 4 with Parkinsonism were examined. A 1msec duration pulse below the pain threshold was applied to the median and ulnar nerves at the elbow and wrist. The activities of the biceps, triceps, flexor carpi radialis, forearm extensors and abductor pollicis brevis were recorded with surface electrodes. The most frequently observed response in normal subjects and hemiplegic patients occurred in the biceps, and had a latency of about 30msec. The other frequently elicited response in normal subjects and hemiplegic patients was in the forearm extensors. Recovery curves were obtained for the biceps response. A significant difference between normal subjects and hemiplegic patients was found. In the patients suffering from Parkinsonism, as well as in demented patients, one could record easily polysynpatic reflexes from other forearm muscles. This suggests the presence of basal ganglia damage in atrophic dementias.

  14. Tendon of the long head of the biceps originating from the rotator cuff - An uncommon anatomical variation: case report.

    PubMed

    Andreoli, Carlos Vicente; Esteves, Leonardo Roure; Figueiredo, Eduardo; Belangero, Paulo Santoro; de Castro Pochini, Alberto; Ejnisman, Benno

    2016-01-01

    Anatomical variations at the origin of the biceps tendon have been described by several authors, but occurrences of an origin in the supraspinatus are rare. It is unclear whether this variation might contribute toward pathological conditions of the shoulder. Our objective here was to describe a case of an anatomical variation in the origin of the tendon of the long head of the biceps. The clinical information, preoperative images and arthroscopic images relating to a patient with an aberrant origin of the long head of the biceps, which was observed during shoulder arthroscopy, were reviewed. In this case study, the origin of the biceps was found in the rotator cuff, without any origin from the supraglenoid tubercle or upper labrum. This variant did not seem to contribute toward the pathological condition of the shoulder, and standard treatment for the concomitant condition was sufficient for treating it.

  15. Real-time noninvasive optical imaging of exercising muscle and brain upon cognitive stimuli

    NASA Astrophysics Data System (ADS)

    Quaresima, Valentina; van der Sluijs, Marco C.; Menssen, Jan; Grillotti, Lucia; Ferrari, Marco; Colier, Willy N.

    2001-06-01

    The monitoring of a single muscle location does not reflect the heterogeneity of the muscle groups activation during exercise. In the past, measurements of oxygen consumption (VO2) at single muscle locations could be carried out non-invasively by near-infrared continuous wave spectroscopy (NIRCWS) at rest or during isometric contractions. In the present study, human regional quadriceps (vastus lateralis and rectus femoris) VO2 was investigated at rest and during maximal voluntary contractions using a 12- channel NIRCWS system with an acquisition time of 0.1 s.

  16. Musculotopic organization of the motor neurons supplying the mouse hindlimb muscles: a quantitative study using Fluoro-Gold retrograde tracing.

    PubMed

    Bácskai, Tímea; Rusznák, Zoltán; Paxinos, George; Watson, Charles

    2014-01-01

    We have mapped the motor neurons (MNs) supplying the major hindlimb muscles of transgenic (C57/BL6J-ChAT-EGFP) and wild-type (C57/BL6J) mice. The fluorescent retrograde tracer Fluoro-Gold was injected into 19 hindlimb muscles. Consecutive transverse spinal cord sections were harvested, the MNs counted, and the MN columns reconstructed in 3D. Three longitudinal MN columns were identified. The dorsolateral column extends from L4 to L6 and consists of MNs innervating the crural muscles and the foot. The ventrolateral column extends from L1 to L6 and accommodates MNs supplying the iliopsoas, gluteal, and quadriceps femoris muscles. The middle part of the ventral horn hosts the central MN column, which extends between L2 and L6 and consists of MNs for the thigh adductor, hamstring, and quadratus femoris muscles. Within these longitudinal columns, the arrangement of the different MN groups reflects their somatotopic organization. MNs innervating muscles developing from the dorsal (e.g., quadriceps) and ventral muscle mass (e.g., hamstring) are situated in the lateral and medial part of the ventral gray, respectively. MN pools belonging to proximal muscles (e.g., quadratus femoris and iliopsoas) are situated ventral to those supplying more distal ones (e.g., plantar muscles). Finally, MNs innervating flexors (e.g., posterior crural muscles) are more medial than those belonging to extensors of the same joint (e.g., anterior crural muscles). These data extend and modify the MN maps in the recently published atlas of the mouse spinal cord and may help when assessing neuronal loss associated with MN diseases.

  17. BICEP2/Keck - Planck joint analysis and prospects for Galactic foreground removal from CMB observations

    NASA Astrophysics Data System (ADS)

    Crill, Brendan

    2015-08-01

    The joint analysis of 150 GHz polarized maps from BICEP2 and Keck Array at 150 GHz with Planck data at 353 GHzallowed the removal of Galactic dust contamination from the measurement of lensed B-modes in the deep (57 nK deg)BICEP2/Keck maps as well as setting an upper limit on the primordial gravitational wave background from inflation. We present this analysis, describe prospects for polarized foreground cleaning of future suborbitalmeasurements of CMB, and additionally describe Planck's measurements of the spatial correlation of polarizedemission from synchrotron and dust at high galactic latitude, which complicates the removal of Galactic foregrounds at the foregroundminimum of 70-100 GHz.

  18. Nonoperative Management (Including Ultrasound-Guided Injections) of Proximal Biceps Disorders.

    PubMed

    Schickendantz, Mark; King, Dominic

    2016-01-01

    Nonoperative management of conditions of the long head of biceps tendon (LHBT) involves a multifaceted approach, addressing the entire shoulder complex in addition to conditions that involve the LHBT. LHBT pathologic conditions are divided into 3 categories: inflammation, instability and rupture. This article provides an overview of a nonoperative treatment algorithm that addresses these specific categories and includes a review of ultrasound-guided injection techniques used in the diagnosis and management of LHBT disorders.

  19. Radioulnar synostosis after the two-incision biceps repair: a standardized treatment protocol.

    PubMed

    Sotereanos, Dean G; Sarris, Ioannis; Chou, Kent H

    2004-01-01

    The purpose of this study was to evaluate the results of a 1-incision posterolateral surgical approach with concomitant irradiation (700 rad) for early resection of synostosis after a 2-incision biceps repair. Between 1992 and 2000, 8 patients with radioulnar synostosis after a 2-incision biceps repair were evaluated and treated, with a mean age of 38 years (range, 29-47 years). The mean time between tendon repair and resection of the synostosis was 7 months (range, 4-14 months). The mean follow-up was 27 months (range, 13-36 months). All patients had 0 degrees of forearm rotation preoperatively. Postoperatively, all patients underwent postoperative radiotherapy in two divided doses for a total of 700 cGy. At a mean follow-up of 27 months, the rotation arc of the forearm improved to 155 degrees (range, 140 degrees -170 degrees ). The strength of supination was 80% (range, 70%-90%) of the contralateral limb. Seven of the eight patients had no pain after activities of daily living or work. One had mild pain after prolonged activity. No radiographic or clinical evidence of synostosis recurrence was seen at final follow-up. We believe that resection of most radioulnar synostoses after 2-incision biceps repair can be achieved safely and efficaciously through one posterolateral incision.

  20. Ultrasound-guided platelet-rich plasma injection for distal biceps tendinopathy

    PubMed Central

    Bell, Simon N; Connell, David; Coghlan, Jennifer A

    2015-01-01

    Background Distal biceps tendinopathy is an uncommon cause of elbow pain. The optimum treatment for cases refractory to conservative treatment is unclear. Platelet-rich plasma has been used successfully for other tendinopathies around the elbow. Methods Six patients with clinical and radiological evidence of distal biceps tendinopathy underwent ultrasound-guided platelet-rich plasma (PRP) injection. Clinical examination findings, visual analogue score (VAS) for pain and Mayo Elbow Performance scores were recorded. Results The Mayo Elbow Performance Score improved from 68.3 (range 65 to 85) (fair function) to 95 (range 85 to 100) (excellent function). The VAS at rest improved from a mean of 2.25 (range 2 to 5) pre-injection to 0. The VAS with movement improved from a mean of 7.25 (range 5 to 8) pre-injection to 1.3 (range 0 to 2). No complications were noted. Discussion Ultrasound-guided PRP injection appears to be a safe and effective treatment for recalcitrant cases of distal biceps tendinopathy. Further investigation with a randomized controlled trial is needed to fully assess its efficacy. PMID:27582965

  1. Two-body space dynamics technology demonstration for the biceps small satellite mission

    NASA Astrophysics Data System (ADS)

    Tyc, G.; Vigneron, F. R.; Jablonski, A. M.

    1994-03-01

    The recently proposed Canadian BICEPS mission requires co-orbiting two small satellites that allow for scientific experiments to be performed at a range of separation distances. Two implementation options have been identified: the preferred approach is to tether the two subsatellites and spin them in a cartwheeling manner to maintain tension in the tether; and the other is to use two free-flying small satellites with reaction control capability on one satellite so that it can be maneuvered relative to the other. One of the scientific objectives of the BICEPS mission is to study the dynamics of this two-body configuration. This paper primarily describes the proposed dynamics-related research activities associated with the tethered configuration, and a brief research summary is provided for the free-flying configuration. The deployment strategy of the tethered configuration is also described and a preliminary dynamics analysis is presented. It is shown that a cold-gas propulsion system is needed on at least one subsatellite to spin-up the system at several stages during the tether deployment in order to maintain tether tensions below 2250 N (approximately 500 lb). Generally, it is believed that the BICEPS mission offers possibilities for technology advancement of co-orbiting small satellites, and in particular tethered small satellites - and in so doing would develop a Canadian niche technology area.

  2. Single and dual incision technique for acute distal biceps rupture: clinical and functional outcomes

    PubMed Central

    Guglielmino, Claudia; Massimino, Paolo; Ioppolo, Francesco; Castorina, Sergio; Musumeci, Giuseppe; Di Giunta, Angelo

    2016-01-01

    Summary Background Distal bicep tendon injuries are a traumatic event though rather rare. The pathogenesis is not entirely clear. The most common cause for injury is an unexpected load on the biceps when the elbow is in an extended position. Although several studies have provided insight into the pathogenetic processes of the lesion, the literature suggests to treat all injuries surgically (whether partial or total) if there is high functional demand. Methods Between January 2006 and March 2016 were studied 20 patients surgically treated for a disconnected distal bicep, 15 with a total lesion and 5 with a partial lesion. The patients were divided into 2 groups. Surgical access with single incision was performed on 13 patients while a double surgical access was performed on 7 patients. The clinical and functional results were studied using an Ewald System Score (ESS). Results In both groups, the most rapid improvement was achieved for the parameters of pain and deformity with excellent results, while those of function and movement were normalized as gradual and progressive over next 2 months. Conclusion The clinical and functional outcomes during the follow-up examination after surgery showed excellent results in patients treated with both types of surgical procedures. PMID:28217566

  3. The Knotted Sky II: does BICEP2 require a nontrivial primordial power spectrum?

    SciTech Connect

    Abazajian, Kevork N.; Aslanyan, Grigor; Easther, Richard; Price, Layne C. E-mail: g.aslanyan@auckland.ac.nz E-mail: lpri691@aucklanduni.ac.nz

    2014-08-01

    An inflationary gravitational wave background consistent with BICEP2 is difficult to reconcile with a simple power-law spectrum of primordial scalar perturbations. Tensor modes contribute to the temperature anisotropies at multipoles with l∼< 100, and this effect — together with a prior on the form of the scalar perturbations — was the source of previous bounds on the tensor-to-scalar ratio. We compute Bayesian evidence for combined fits to BICEP2 and Planck for three nontrivial primordial spectra: a) a running spectral index, b) a cutoff at fixed wavenumber, and c) a spectrum described by a linear spline with a single internal knot. We find no evidence for a cutoff, weak evidence for a running index, and significant evidence for a ''broken'' spectrum. Taken at face-value, the BICEP2 results require two new inflationary parameters in order to describe both the broken scale invariance in the perturbation spectrum and the observed tensor-to-scalar ratio. Alternatively, this tension may be resolved by additional data and more detailed analyses.

  4. Inflationary generalized Chaplygin gas and dark energy in light of the Planck and BICEP2 experiments

    NASA Astrophysics Data System (ADS)

    Dinda, B