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Sample records for muscle volume comparison

  1. Muscle shape consistency and muscle volume prediction of thigh muscles.

    PubMed

    Mersmann, F; Bohm, S; Schroll, A; Boeth, H; Duda, G; Arampatzis, A

    2015-04-01

    The present study investigated the applicability of a muscle volume prediction method using only the muscle length (L(M)), the maximum anatomical cross-sectional area (ACSA(max)), and a muscle-specific shape factor (p) on the quadriceps vastii. L(M), ACSA(max), muscle volume, and p were obtained from magnetic resonance images of the vastus intermedius (VI), lateralis (VL), and medialis (VM) of female (n = 20) and male (n = 17) volleyball athletes. The average p was used to predict muscle volumes (V(p)) using the equation V(p)  = p × ACSA(max)  × L(M). Although there were significant differences in the muscle dimensions between male and female athletes, p was similar and on average 0.582, 0.658, 0.543 for the VI, VL, and VM, respectively. The position of ACSA(max) showed low variability and was at 57%, 60%, and 81% of the thigh length for VI, VL, and VM. Further, there were no significant differences between measured and predicted muscle volumes with root mean square differences of 5-8%. These results suggest that the muscle shape of the quadriceps vastii is independent of muscle dimensions or sex and that the prediction method could be sensitive enough to detect changes in muscle volume related to degeneration, atrophy, or hypertrophy.

  2. Comparison between standard and reduced volume radiotherapy in bladder preservation trimodality protocol for muscle-invasive bladder cancer patients

    PubMed Central

    Arafat, Waleed; Darwish, Azza; Naoum, George E; Sameh, Wael; Husseiny, Gamal El; Abd-El-Gawad, Fathy; Samir, Mostafa

    2016-01-01

    Aim Our aim is to compare the toxicity, pelvic nodal relapse, and overall survival of whole bladder irradiation only to the standard technique of whole pelvis irradiation followed by bladder boost in patients with muscle-invasive bladder carcinoma undergoing bladder preservation protocol. Material and method A total of 60 patients with transitional cell carcinoma, stage T2-3, N0, M0 bladder cancer were subjected to maximal transurethral resection bladder tumour (TURB). Then, the patients were randomised into two groups: group I (30 patients) to receive whole pelvis radiotherapy 44 Gy followed by 20 Gy bladder boost. While group II (30 patients) were randomised to receive whole bladder radiotherapy alone for a total dose of 64 Gy. In both groups, concomitant cisplatin and paclitaxel were given weekly throughout the whole course of radiotherapy where conventional 2 Gy/fraction were used. Additionally, four cycles of adjuvant cisplatin and paclitaxel were given after the end of the chemoradiotherapy induction course. Results The first assessment after the induction chemoradiotherapy showed that complete response was achieved in 73.3% of patients in group I and 76.7% of the patients in group II. After a median follow-up of 2 years, regional relapse occurred in 7.1% of patients in group I and 10.3% in group II. (p = 1). Distant metastases were detected in 17.9% of patient in group I and 13.8% in group II (p = 0.73). The 2-year disease-free survival was 60% in group I and 63.3% in group II (p = 0.79). The whole 2-year overall survival was 75% in group I and 79.3% in group II (p = 0.689). Radiation gastrointestinal (GI) acute toxicity was higher in group I than in group II (p = 0.001), while late GI radiation toxicity was comparable in both groups. Conclusion Treating the bladder only, without elective pelvic nodal irradiation, did not compromise pelvic control rate, but significantly decreased the acute radiation toxicity. PMID:27899955

  3. Muscle volume alterations in spastic muscles immediately following botulinum toxin type-A treatment in children with cerebral palsy.

    PubMed

    Williams, Sîan A; Reid, Siobhan; Elliott, Catherine; Shipman, Peter; Valentine, Jane

    2013-09-01

    With evidence for an atrophic effect of botulinum toxin type A (BoNT-A) documented in typically developing muscles, this study investigated the immediate morphological alterations of muscles in children with cerebral palsy (CP) after BoNT-A treatment. Fifteen children (10 males, five females; age range 5-11y, mean age 8y 5mo, SD 1y 10mo) with spastic diplegic CP [Gross Motor Function Classification System Levels I (n=9) and II (n=6)] receiving BoNT-A injections for spasticity management were included. None of the children was a first-time receiver of BoNT-A. Magnetic resonance imaging and Mimics software assessed muscle volume, timed 2 weeks before and 5 weeks after injection. All participants received BoNT-A bilaterally to the gastrocnemius muscle, and five participants also received BoNT-A bilaterally to the medial hamstring muscles. Functional assessment measures used were the 6-Minute Walk Test (6-MWT), the Timed Up and Go (TUG) test, and hand-held dynamometry. Whilst total muscle group volume of the injected muscle group remained unchanged, a 4.47% decrease in the injected gastrocnemius muscle volume (p=0.01) and a 3.96% increase in soleus muscle volume (p=0.02) was evident following BoNT-A. There were no statistically significant changes in function after BoNT-A as assessed by the TUG. There was also no statistically significant change in distance covered in the 6-MWT. Muscle strength, as assessed using hand-held dynamometry was also not statistically different after BoNT-A treatment. Muscle volume decreases were observed in the injected muscle (gastrocnemius), with synergistic muscle hypertrophy that appeared to compensate for this decrement. The 4% to 5% decrease in the volume of BoNT-A injected muscles are not dramatic in comparison to reports in recent animal studies, and are a positive indication for BoNT-A, particularly as it also did not negatively alter function. © 2013 Mac Keith Press.

  4. In vitro measurement of muscle volume with 3-dimensional ultrasound.

    PubMed

    Delcker, A; Walker, F; Caress, J; Hunt, C; Tegeler, C

    1999-05-01

    The aim was to test the accuracy of muscle volume measurements with a new 3-dimensional (3-D) ultrasound system, which allows a freehand scanning of the transducer with an improved quality of the ultrasound images and therefore the outlines of the muscles. Five resected cadaveric hand muscles were insonated and the muscle volumes calculated by 3-D reconstructions of the acquired 2-D ultrasound sections. Intra-reader, inter-reader and follow-up variability were calculated, as well as the volume of the muscle tissue measured by water displacement. In the results, 3-D ultrasound and water displacement measurements showed an average deviation of 10.1%; Data of 3-D ultrasound measurements were: intra-reader variability 2.8%; inter-reader variability 2.4% and follow-up variability 2.3%. 3-D measurements of muscle volume are valid and reliable. Serial sonographic measurements of muscle may be able to quantitate changes in muscle volume that occur in disease and recovery.

  5. Association between Thigh Muscle Volume and Leg Muscle Power in Older Women

    PubMed Central

    Machann, Juergen; Blatzonis, Konstantinos; Rapp, Kilian

    2016-01-01

    The construct of sarcopenia is still discussed with regard to best appropriate measures of muscle volume and muscle function. The aim of this post-hoc analysis of a cross-sectional experimental study was to investigate and describe the hierarchy of the association between thigh muscle volume and measurements of functional performance in older women. Thigh muscle volume of 68 independently living older women (mean age 77.6 years) was measured via magnetic resonance imaging. Isometric strength was assessed for leg extension in a movement laboratory in sitting position with the knee flexed at 90° and for hand grip. Maximum and habitual gait speed was measured on an electronic walk way. Leg muscle power was measured during single leg push and during sit-to-stand performance. Thigh muscle volume was associated with sit-to-stand performance power (r = 0.628), leg push power (r = 0.550), isometric quadriceps strength (r = 0.442), hand grip strength (r = 0.367), fast gait speed (r = 0.291), habitual gait speed (r = 0.256), body mass index (r = 0.411) and age (r = -0.392). Muscle power showed the highest association with thigh muscle volume in healthy older women. Sit-to-stand performance power showed an even higher association with thigh muscle volume compared to single leg push power. PMID:27315060

  6. Association between Thigh Muscle Volume and Leg Muscle Power in Older Women.

    PubMed

    Lindemann, Ulrich; Mohr, Christian; Machann, Juergen; Blatzonis, Konstantinos; Rapp, Kilian; Becker, Clemens

    2016-01-01

    The construct of sarcopenia is still discussed with regard to best appropriate measures of muscle volume and muscle function. The aim of this post-hoc analysis of a cross-sectional experimental study was to investigate and describe the hierarchy of the association between thigh muscle volume and measurements of functional performance in older women. Thigh muscle volume of 68 independently living older women (mean age 77.6 years) was measured via magnetic resonance imaging. Isometric strength was assessed for leg extension in a movement laboratory in sitting position with the knee flexed at 90° and for hand grip. Maximum and habitual gait speed was measured on an electronic walk way. Leg muscle power was measured during single leg push and during sit-to-stand performance. Thigh muscle volume was associated with sit-to-stand performance power (r = 0.628), leg push power (r = 0.550), isometric quadriceps strength (r = 0.442), hand grip strength (r = 0.367), fast gait speed (r = 0.291), habitual gait speed (r = 0.256), body mass index (r = 0.411) and age (r = -0.392). Muscle power showed the highest association with thigh muscle volume in healthy older women. Sit-to-stand performance power showed an even higher association with thigh muscle volume compared to single leg push power.

  7. 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.

  8. Comparison of muscle activity and tissue oxygenation during strength training protocols that differ by their organisation, rest interval between sets, and volume.

    PubMed

    Penzer, Félix; Cabrol, Alexis; Baudry, Stéphane; Duchateau, Jacques

    2016-09-01

    The acute effects of a single training session on muscle activity and oxygenation were compared between a new strength training method (3/7 protocol) and a more classical method (4 × 6 and 8 × 6 protocols). All protocols consisted of lifting and lowering a load (70 % 1RM) with the elbow-flexor muscles. The 3/7 protocol involved 5 sets of increasing number of repetitions during successive sets (from 3 to 7 repetitions), and brief rest interval between sets (15 s). The other two protocols consisted of either 4 or 8 sets of 6 repetitions with a rest interval between sets of 2.5 min. Surface electromyogram (EMG) of biceps brachii, brachioradialis, and triceps brachii, and tissue oxygenation index (TOI) of the two elbow flexors were recorded. For all muscles, EMG increased similarly (50-60 %) during each set in the 4 × 6 and 8 × 6 protocols but gradually during the successive sets in the 3/7 protocol. At protocol completion, EMG reached greater value (p < 0.003) in the 3/7 protocol. TOI decreased during each set in all protocols but contrary to 4 × 6 and 8 × 6 protocols, it did not return to resting values between sets in the 3/7 protocol. The deficit in TOI per repetition was greater (p < 0.001) in the 3/7 (-142.5 ± 48.8 %) than 4 × 6 (-113.1 ± 48.8 %) and 8 × 6 (-105.9 ± 59.2 %) protocols for biceps brachii but not brachioradialis. The results indicate that brief rest interval between sets and incremental number of repetitions in successive sets induced greater muscle activity and metabolic changes compared with method of constant repetitions per set and longer rest interval.

  9. Skeletal muscle volume following dehydration induced by exercise in heat

    PubMed Central

    2012-01-01

    Background Intracellular skeletal muscle water is redistributed into the extracellular compartment during periods of dehydration, suggesting an associated decline in muscle volume. The purpose of this study was to evaluate skeletal muscle volume in active (knee extensors (KE)) and less active (biceps/triceps brachii, deltoid) musculature following dehydration induced by exercise in heat. Methods Twelve participants (seven men, five women) cycled in the heat under two conditions: (1) dehydration (DHYD) resulting in 3% and 5% losses of estimated total body water (ETBW), which was assessed by changes in body mass, and (2) fluid replacement (FR) where 3% and 5% losses of ETBW were counteracted by intermittent (20 to 30 min) fluid ingestion via a carbohydrate-electrolyte beverage. During both conditions, serum osmolality and skeletal muscle volume (assessed by magnetic resonance imaging) were measured at baseline and at the 3% and 5% ETBW loss measurement points. Results In DHYD, serum osmolality increased at 3% (p = 0.005) and 5% (p < 0.001) ETBW losses, while FR decreased serum osmolality at the 5% loss of ETBW time point (p = 0.009). In DHYD, KE muscle volume declined from 1,464 ± 446 ml to 1,406 ± 425 ml (3.9%, p < 0.001) at 3% ETBW loss and to 1,378 ± 421 ml (5.9%, p < 0.001) at 5% ETBW loss. The largest decline in KE volume in DYHD occurred in the mid-belly (31 ml, p = 0.001) and proximal (24 ml, p = 0.001) regions of the grouped vasti muscles. There were no changes in volume for the biceps/triceps (p = 0.35) or deltoid (p = 0.92) during DHYD. FR prevented the loss of KE muscle volume at 3% (1,430 ± 435 ml, p = 0.074) and 5% (1,431 ± 439 ml, p = 0.156) ETBW loss time points compared to baseline (1,445 ± 436 ml). Conclusions Following exercise in the heat, the actively contracting muscles lost volume, while replacing lost fluids intermittently during exercise in heat prevented this decline

  10. Volume Control by Muscle Fibers of the Blue Crab

    PubMed Central

    Lang, Michael A.; Gainer, Harold

    1969-01-01

    Single isolated muscle fibers from the walking legs of the blue crab, Callinectes sapidus act as Boyle-van't Hoff osmometers with an osmotically inactive volume of 33 %. Fibers in hypotonic salines undergo a spontaneous volume readjustment toward the initial volumes of the cells found in isotonic salines. The volume readjustment is initiated by the increase in cell volume in hypotonic salines and appears to be dependent on the duration of exposure of the fiber to external sodium, the sodium concentration, and the pH of the external medium. The volume-readjusted cells continue to behave as osmometers, but with an increased relative osmotically inactive volume and a decreased internal resistivity. The decreases in cell volumes appear to be, in large part, due to losses of osmotically active nonelectrolytes from the cells. PMID:5767335

  11. Pressure-volume behaviour of the rat upper airway: effects of tongue muscle activation

    PubMed Central

    Bailey, E Fiona; Fregosi, Ralph F

    2003-01-01

    Our hypothesis was that the simultaneous activation of tongue protrudor and retractor muscles (co-activation) would constrict and stiffen the pharyngeal airway more than the independent activation of tongue protrudor muscles. Upper airway stiffness was determined by injecting known volumes of air into the sealed pharyngeal airway of the anaesthetized rat while measuring nasal pressure under control (no-stimulus) and stimulus conditions (volume paired with hypoglossal (XII) nerve stimulation). Stimulation of the whole XII nerves (co-activation) or the medial XII branches (protrudor activation) effected similar increases in total pharyngeal airway stiffness. Importantly, co-activation produced volume compression (airway narrowing) at large airway volumes (P < 0.05), but had no effect on airway dimension at low airway volumes. In comparison, protrudor activation resulted in significant volume expansion (airway dilatation) at low airway volumes and airway narrowing at high airway volumes (P < 0.05). In conclusion, both co-activation and independent protrudor muscle activation increase airway stiffness. However, their effects on airway size are complex and depend on the condition of the airway at the time of activation. PMID:12640023

  12. Relationship between quadriceps femoris muscle volume and muscle torque after anterior cruciate ligament rupture.

    PubMed

    Konishi, Yu; Oda, Toshiaki; Tsukazaki, Satoshi; Kinugasa, Ryuta; Hirose, Norikazu; Fukubayashi, Toru

    2011-04-01

    The purpose of this study was to obtain evidence to support the hypothesis that motor unit recruitment is reduced in the quadriceps femoris (QF) of patients with ACL rupture. We compared muscle torque per unit volume in the QF from injured and uninjured sides to normal subjects. If high-threshold motor unit recruitment is reduced in patients with ACL rupture, this reduction will theoretically lead to a reduction in muscle torque per unit volume compared to the control group. The subjects included 22 patients with ACL rupture and 22 subjects with no history of knee injury. To identify the muscle torque per unit volume, the isokinetic peak torque was divided by QF volume which was obtained by MRI. Tests revealed that the mean muscle torque per unit volume of the uninjured and injured sides was significantly lower than those of the control group. This study demonstrated that the values of the muscle torque per unit volume of both injured and uninjured sides of patients with ACL rupture were significantly lower than those of the control group, thereby providing indirect evidence of the hindrance of motor unit recruitment in these patients. The results of the present study also indicate that there may be bilateral QF weakness in patients with ACL rupture. Since persistent QF weakness is a significant barrier to effective rehabilitation in patients with ACL injuries, a better understanding of the underlying mechanisms will allow clinicians and scientists to develop more effective therapeutic strategies for patient rehabilitation.

  13. Contractile properties of esophageal striated muscle: comparison with cardiac and skeletal muscles in rats.

    PubMed

    Shiina, Takahiko; Shima, Takeshi; Masuda, Kazuaki; Hirayama, Haruko; Iwami, Momoe; Takewaki, Tadashi; Kuramoto, Hirofumi; Shimizu, Yasutake

    2010-01-01

    The external muscle layer of the mammalian esophagus consists of striated muscles. We investigated the contractile properties of esophageal striated muscle by comparison with those of skeletal and cardiac muscles. Electrical field stimulation with single pulses evoked twitch-like contractile responses in esophageal muscle, similar to those in skeletal muscle in duration and similar to those in cardiac muscle in amplitude. The contractions of esophageal muscle were not affected by an inhibitor of gap junctions. Contractile responses induced by high potassium or caffeine in esophageal muscle were analogous to those in skeletal muscle. High-frequency stimulation induced a transient summation of contractions followed by sustained contractions with amplitudes similar to those of twitch-like contractions, although a large summation was observed in skeletal muscle. The results demonstrate that esophageal muscle has properties similar but not identical to those of skeletal muscle and that some specific properties may be beneficial for esophageal peristalsis.

  14. The determinants of transverse tubular volume in resting skeletal muscle

    PubMed Central

    Sim, Jingwei; Fraser, James A

    2014-01-01

    The transverse tubular (t)-system of skeletal muscle couples sarcolemmal electrical excitation with contraction deep within the fibre. Exercise, pathology and the composition of the extracellular fluid (ECF) can alter t-system volume (t-volume). T-volume changes are thought to contribute to fatigue, rhabdomyolysis and disruption of excitation–contraction coupling. However, mechanisms that underlie t-volume changes are poorly understood. A multicompartment, history-independent computer model of rat skeletal muscle was developed to define the minimum conditions for t-volume stability. It was found that the t-system tends to swell due to net ionic fluxes from the ECF across the access resistance. However, a stable t-volume is possible when this is offset by a net efflux from the t-system to the cell and thence to the ECF, forming a net ion cycle ECF→t-system→sarcoplasm→ECF that ultimately depends on Na+/K+-ATPase activity. Membrane properties that maximize this circuit flux decrease t-volume, including PNa(t) > PNa(s), PK(t) < PK(s) and N(t) < N(s) [P, permeability; N, Na+/K+-ATPase density; (t), t-system membrane; (s), sarcolemma]. Hydrostatic pressures, fixed charges and/or osmoles in the t-system can influence the magnitude of t-volume changes that result from alterations in this circuit flux. Using a parameter set derived from literature values where possible, this novel theory of t-volume was tested against data from previous experiments where t-volume was measured during manipulations of ECF composition. Predicted t-volume changes correlated satisfactorily. The present work provides a robust, unifying theoretical framework for understanding the determinants of t-volume. PMID:25384782

  15. Volume control by muscle fibers of the blue crab. Volume readjustment in hypotonic salines.

    PubMed

    Lang, M A; Gainer, H

    1969-03-01

    Single isolated muscle fibers from the walking legs of the blue crab, Callinectes sapidus act as Boyle-van't Hoff osmometers with an osmotically inactive volume of 33 %. Fibers in hypotonic salines undergo a spontaneous volume readjustment toward the initial volumes of the cells found in isotonic salines. The volume readjustment is initiated by the increase in cell volume in hypotonic salines and appears to be dependent on the duration of exposure of the fiber to external sodium, the sodium concentration, and the pH of the external medium. The volume-readjusted cells continue to behave as osmometers, but with an increased relative osmotically inactive volume and a decreased internal resistivity. The decreases in cell volumes appear to be, in large part, due to losses of osmotically active nonelectrolytes from the cells.

  16. Relationships of hamstring muscle volumes to lateral tibial slope.

    PubMed

    Schmitz, Randy J; Kulas, Anthony S; Shultz, Sandra J; Waxman, Justin P; Wang, Hsin-Min; Kraft, Robert A

    2017-09-29

    Greater posterior-inferior directed slope of the lateral tibial plateau (LTS) has been demonstrated to be a prospective ACL injury risk factor. Trainable measures to overcome a greater LTS need to be identified for optimizing injury prevention protocols. It was hypothesized that Healthy individuals with greater LTS who have not sustained an ACL injury would have a larger lateral hamstring volume. Eleven healthy females (mean +/- standard deviation) (1.63±0.07m, 62.0±8.9kg, 22.6±2.9years) & 10 healthy males (1.80±0.08m, 82.3±12.0kg, 23.2±3.4years) underwent magnetic resonance imaging of the left knee and thigh. LTS, semitendinosus muscle volume, and biceps femoris long head muscle volume were obtained from imaging data. After controlling for potential sex confounds (R(2)=.00; P=.862), lesser semitendinosus volume and greater biceps femoris-long head volume were indicative of greater LTS (R(2)∆=.30, P=.008). Healthy individuals with greater LTS have a muscular morphologic profile that includes a larger biceps femoris-long head volume. This may be indicative of a biomechanical strategy that relies more heavily on force generation of the lateral hamstring and is less reliant on force generation of the medial hamstring. Level IV. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Relationship between muscle volume and muscle torque of the hamstrings after anterior cruciate ligament reconstruction.

    PubMed

    Konishi, Yu; Fukubayashi, Toru

    2010-01-01

    The muscle torque per unit volume of the hamstrings on the injured and uninjured sides in patients with ACL reconstruction were compared with participants with no history of knee injury to examine whether a similar mechanism leading to quadriceps weakness exists in the hamstrings of these patients. The study population consisted of 18 and 52 patients at volume was measured on MRI. To identify the muscle torque per unit volume, the peak torque of knee flexion was divided by the hamstring volume. Most muscle torque per unit volume indexes were not significantly different between the patients at muscle torque per unit volume of patients at 12 months in both injured (0.118+/-0.03 Nm/cm(3), 60 degrees /s; 0.092+/-0.02 Nm/cm(3), 180 degrees /s) and uninjured sides (0.120+/-0.03 Nm/cm(3) at 60 degrees /s; 0.094+/-0.02 Nm/cm(3), 180 degrees /s) were significantly lower than those of controls (P<0.01). We found no evidence of recruitment disorder in the hamstrings of the patients. The results of this study indicated that the mechanism of muscle weakness of the hamstrings after reconstruction was different from that of the quadriceps, although the precise mechanism remains to be determined. Copyright (c) 2008 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  18. Reference data on muscle volumes of healthy human pelvis and lower extremity muscles: an in vivo magnetic resonance imaging feasibility study.

    PubMed

    Lube, Juliane; Cotofana, Sebastian; Bechmann, Ingo; Milani, Thomas L; Özkurtul, Orkun; Sakai, Tatsuo; Steinke, Hanno; Hammer, Niels

    2016-01-01

    Muscle volumes are of crucial interest when attempting to analyze individual physical performance and disease- or age-related alterations in muscle morphology. However, very little reference data are available in the literature on pelvis and lower extremity muscle volumes originating from healthy and young individuals. Furthermore, it is of interest if representative muscle volumes, covering large anatomical regions, can be obtained using magnetic resonance imaging (MRI) in a setting similar to the clinical routine. Our objective was therefore to provide encompassing, bilateral, 3-T MRI-based datasets on muscle volumes of the pelvis and the lower limb muscles. T1-weighted 3-T MRI records were obtained bilaterally from six young and healthy participants. Three-dimensional volumes were compiled from 28 muscles and muscle groups of each participant before the muscle volumes were computed. Muscle volumes were obtained from 28 muscles and muscle groups of the pelvis and lower extremity. Volumes were larger in male than in female participants. Volumes of the dominant and non-dominant sides were similar in both genders. The obtained results were in line with volumetric data obtained from smaller anatomical areas, thus extending the available datasets. This study provides an encompassing and feasible approach to obtain data on the muscle volumes of pelvic and limb muscles of healthy, young, and physically active individuals. The respective data form a basis to determine effects of therapeutic approaches, progression of diseases, or technical applications like automated segmentation algorithms applied to different populations.

  19. Muscle-like actuators? A comparison between three electroactive polymers

    NASA Astrophysics Data System (ADS)

    Meijer, Kenneth; Rosenthal, Marc S.; Full, Robert J.

    2001-07-01

    Muscles fulfill several functions within an animal's body. During locomotion they propel and control the limbs in unstructured environments. Therefore, the functional workspace of muscle needs to be represented by variables describing energy management (i.e. power output, efficiency) as well as control aspects (i.e. stiffness, damping). Muscles in the animal kingdom vary greatly with respect to those variables. To study if ElectroActive Polymer's (EAP) can be considered as artificial muscles we are making a direct comparison between the contractile properties of EAP's and biological muscle. We have measured the functional workspace of EAP actuators using the same setup and techniques that we use to test biological muscle. We evaluated the properties of three different EAP materials; the acrylic and silicone dielectric elastomers developed at SRI International and the high-energy electron-irradiated co-polymers (p(VDF-TrFE)) developed at the MRL laboratory at Penn State University. Initial results indicate that the EAP materials partly capture the functional workspace of natural muscle and sometimes even exceed the capabilities of muscle. Based on the data we have collected it seems that both EAP technologies have characteristics that could qualify them as artificial muscles.

  20. Experimental comparisons between McKibben type artificial muscles and straight fibers type artificial muscles

    NASA Astrophysics Data System (ADS)

    Nakamura, Taro

    2007-01-01

    This paper describes experimental comparison between a conventional McKibben type artificial muscle and a straight fibers type artificial muscle developed by the authors. A wearable device and a rehabilitation robot which assists a human muscle should have characteristics similar to those of human muscle. In addition, because the wearable device and the rehabilitation robot should be light, an actuator with a high power/weight ratio is needed. At present, the McKibben type is widely used as an artificial muscle, but in fact its physical model is highly nonlinear. Further, the heat and mechanical loss of this actuator are large because of the friction caused by the expansion and contraction of the sleeve. Therefore, the authors have developed an artificial muscle tube in which high strength glass fibers have been built into the tube made from natural latex rubber. As results, experimental results demonstrated that the developed artificial muscle is more effective regarding its fundamental characteristics than that of the McKibben type; the straight fibers types of artificial muscle have more contraction ratio and power, longer lifetime than the McKibben types. And it has almost same characteristics of human muscle for isotonic and isometric that evaluate it dynamically.

  1. Estimation of spinopelvic muscles' volumes in young asymptomatic subjects: a quantitative analysis.

    PubMed

    Amabile, Celia; Moal, Bertrand; Chtara, Oussama Arous; Pillet, Helene; Raya, Jose G; Iannessi, Antoine; Skalli, Wafa; Lafage, Virginie; Bronsard, Nicolas

    2017-04-01

    Muscles have been proved to be a major component in postural regulation during pathological evolution or aging. Particularly, spinopelvic muscles are recruited for compensatory mechanisms such as pelvic retroversion, or knee flexion. Change in muscles' volume could, therefore, be a marker of greater postural degradation. Yet, it is difficult to interpret spinopelvic muscular degradation as there are few reported values for young asymptomatic adults to compare to. The objective was to provide such reference values on spinopelvic muscles. A model predicting the muscular volume from reduced set of MRI segmented images was investigated. A total of 23 asymptomatic subjects younger than 24 years old underwent an MRI acquisition from T12 to the knee. Spinopelvic muscles were segmented to obtain an accurate 3D reconstruction, allowing precise computation of muscle's volume. A model computing the volume of muscular groups from less than six MRI segmented slices was investigated. Baseline values have been reported in tables. For all muscles, invariance was found for the shape factor [ratio of volume over (area times length): SD < 0.04] and volume ratio over total volume (SD < 1.2 %). A model computing the muscular volume from a combination of two to five slices has been evaluated. The five-slices model prediction error (in  % of the real volume from 3D reconstruction) ranged from 6 % (knee flexors and extensors and spine flexors) to 11 % (spine extensors). Spinopelvic muscles' values for a reference population have been reported. A new model predicting the muscles' volumes from a reduced set of MRI slices is proposed. While this model still needs to be validated on other populations, the current study appears promising for clinical use to determine, quantitatively, the muscular degradation.

  2. The Relationship Between Spasticity and Muscle Volume of the Knee Extensors in Children With Cerebral Palsy

    PubMed Central

    Pierce, Samuel R.; Prosser, Laura A.; Lee, Samuel C. K.; Lauer, Richard T.

    2013-01-01

    Purpose The purpose of this study was to examine the relationship between spasticity and muscle volume in children with cerebral palsy (CP), using isokinetic dynamometry and magnetic resonance imaging. Methods A retrospective sample of 8 children with diplegic CP was analyzed. One set of 10 passive knee flexion movements was completed at a velocity of 180° per second with concurrent surface electromyography of the medial hamstrings (MH) and vastus lateralis (VL) to assess knee extensor spasticity. Magnetic resonance imaging was used to measure maximum cross-sectional area and muscle volume of the quadriceps femoris. Results The quadriceps femoris muscle volume was positively correlated with MH reflex activity, VL reflex activity, MH/VL co-contraction, and peak knee extensor passive torque (P < .05). Conclusion The present findings suggest that higher levels of knee extensor muscle spasticity are associated with greater quadriceps muscle volume in children with spastic diplegic CP. PMID:22466388

  3. Automatic quantification of muscle volumes in magnetic resonance imaging scans of the lower extremities.

    PubMed

    Brunner, Gerd; Nambi, Vijay; Yang, Eric; Kumar, Anirudh; Virani, Salim S; Kougias, Panagiotis; Shah, Dipan; Lumsden, Alan; Ballantyne, Christie M; Morrisett, Joel D

    2011-10-01

    Muscle volume measurements are essential for an array of diseases ranging from peripheral arterial disease, muscular dystrophies, neurological conditions to sport injuries and aging. In the clinical setting, muscle volume is not routinely measured due to the lack of standardized ways for its repeatable quantification. In this paper, we present magnetic resonance muscle quantification (MRMQ), a method for the automatic quantification of thigh muscle volume in magnetic resonance imaging (MRI) scans. MRMQ integrates a thigh segmentation and nonuniform image gradient correction step, followed by feature extraction and classification. The classification step leverages prior probabilities, introducing prior knowledge to a maximum a posteriori classifier. MRMQ was validated on 344 slices taken from 60 MRI scans. Experiments for the fully automatic detection of muscle volume in MRI scans demonstrated an averaged accuracy, sensitivity and specificity for leave-one-out cross-validation of 88.3%, 93.6% and 87.2%, respectively.

  4. Effects of training in minimalist shoes on the intrinsic and extrinsic foot muscle volume.

    PubMed

    Chen, Tony Lin-Wei; Sze, Louis K Y; Davis, Irene S; Cheung, Roy T H

    2016-07-01

    Minimalist shoes have gained popularity recently because it is speculated to strengthen the foot muscles and foot arches, which may help to resist injuries. However, previous studies provided limited evidence supporting the link between changes in muscle size and footwear transition. Therefore, this study sought to examine the effects of minimalist shoes on the intrinsic and extrinsic foot muscle volume in habitual shod runners. The relationship between participants' compliance with the minimalist shoes and changes in muscle õvolume was also evaluated. Twenty habitual shod runners underwent a 6-month self-monitoring training program designed for minimalist shoe transition. Another 18 characteristics-matched shod runners were also introduced with the same program but they maintained running practice with standard shoes. Runners were monitored using an online surveillance platform during the program. We measured overall intrinsic and extrinsic foot muscle volume before and after the program using MRI scans. Runners in the experimental group exhibited significantly larger leg (P=0.01, Cohen's d=0.62) and foot (P<0.01, Cohen's d=0.54) muscle after transition. Foot muscle growth was mainly contributed by the forefoot (P<0.01, Cohen's d=0.64) but not the rearfoot muscle (P=0.10, Cohen's d=0.30). Leg and foot muscle volume of runners in the control group remained similar after the program (P=0.33-0.95). A significant positive correlation was found between participants' compliance with the minimalist shoes and changes in leg muscle volume (r=0.51; P=0.02). Habitual shod runners who transitioned to minimalist shoes demonstrated significant increase in leg and foot muscle volume. Additionally, the increase in leg muscle volume was significantly correlated associated with the compliance of minimalist shoe use. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. In vivo pediatric shoulder muscle volumes and their relationship to 3D strength.

    PubMed

    Im, Hyun Soo; Alter, Katharine E; Brochard, Sylvain; Pons, Christelle; Sheehan, Frances T

    2014-08-22

    In the pediatric shoulder, injury and pathology can disrupt the muscle force balance, resulting in severe functional losses. As little data exists pertaining to in vivo pediatric shoulder muscle function, musculoskeletal data are crucially needed to advance the treatment of pediatric shoulder pathology/injury. Therefore, the purpose of this study was to develop a pediatric database of in vivo volumes for the major shoulder muscles and correlate these volumes with maximum isometric flexion/extension, internal/external rotation, and abduction/adduction joint moments. A methodology was developed to derive 3D shoulder muscle volumes and to divide the deltoid into sub-units with unique torque producing capabilities, based on segmentation of three-dimensional magnetic resonance images. Eleven typically developing children/adolescents (4F/7M, 12.0 ± 3.2 years, 150.8 ± 16.7 cm, 49.2 ± 16.4 kg) participated. Correlation and regression analyses were used to evaluate the relationship between volume and maximum, voluntary, isometric joint torques. The deltoid demonstrated the largest (30.4 ± 1.2%) and the supraspinatus the smallest (4.8 ± 0.5%) percent of the total summed volume of all six muscles evaluated. The anterior and posterior deltoid sections were 43.4 ± 3.9% and 56.6 ± 3.9% of the total deltoid volume. The percent volumes were highly consistent across subjects. Individual muscle volumes demonstrated moderate-high correlations with torque values (0.70-0.94, p<0.001). This study presents a comprehensive database documenting normative pediatric shoulder muscle volume. Using these data a clear relationship between shoulder volume and the torques they produce was established in all three rotational degrees-of-freedom. This study furthers the understanding of shoulder muscle function and serves as a foundation for evaluating shoulder injury/pathology in the pediatric/adolescent population.

  6. In Vivo Pediatric Shoulder Muscle Volumes and Their Relationship to 3D Strength

    PubMed Central

    Im, Hyun Soo; Alter, Katharine E.; Brochard, Sylvain; Pons, Christelle; Sheehan, Frances T.

    2017-01-01

    In the pediatric shoulder, injury and pathology can disrupt the muscle force balance, resulting in severe functional losses. As little data exists pertaining to in vivo pediatric shoulder muscle function, musculoskeletal data are crucially needed to advance the treatment of pediatric shoulder pathology/injury. Therefore, the purpose of this study was to develop a pediatric database of in vivo volumes for the major shoulder muscles and correlate these volumes to maximum isometric flexion/extension, internal/external rotation, and abduction/adduction joint moments. A methodology was developed to derive 3D shoulder muscle volumes and to divide the deltoid into sub-units with unique torque producing capabilities, based on segmentation of three-dimensional magnetic resonance images. Eleven typically developing children/adolescents (4F/7M, 12.0±3.2years, 150.8±16.7cm, 49.2±16.4kg) participated. Correlation and regression analyses were used to evaluate the relationship between volume and maximum, voluntary, isometric joint torques. The deltoid demonstrated the largest (30.4 ±1.2%) and the supraspinatus the smallest (4.8 ± 0.5%) percent of the total summed volume of all six muscles evaluated. The anterior and posterior deltoid sections were 43.4±3.9% and 56.6±3.9% of the total deltoid volume. The percent volumes were highly consistent across subjects. Individual muscle volumes demonstrated moderate-high correlations with torque values (0.70–0.94, p<0.001). This study presents a comprehensive database documenting normative pediatric shoulder muscle volume. Using these data a clear relationship between shoulder volume and the torques they produce was established in all three rotational degrees-of-freedom. This study furthers the understanding of shoulder muscle function and serves as a foundation for evaluating shoulder injury/pathology in the pediatric/adolescent population. PMID:24925254

  7. Thigh muscle volume predicted by anthropometric measurements and correlated with physical function in the older adults.

    PubMed

    Chen, B B; Shih, T T F; Hsu, C Y; Yu, C W; Wei, S Y; Chen, C Y; Wu, C H; Chen, C Y

    2011-06-01

    (1) to correlate thigh muscle volume measured by magnetic resonance image (MRI) with anthropometric measurements and physical function in elderly subjects; (2) to predict MRI-measured thigh muscle volume using anthropometric measurements and physical functional status in elderly subjects. Cross-sectional, nonrandomized study. Outpatient clinic in Taiwan. Sixty-nine elderly subjects (33 men and 36 women) aged 65 and older. The anthropometric data (including body height, body weight, waist size, and thigh circumference), physical activity and function (including grip strength, bilateral quadriceps muscle power, the up and go test, chair rise, and five meters walk time) and bioelectrical impedance analysis data (including total body fat mass, fat-free mass, and predictive muscle size) were measured. MRI-measured muscle volume of both thighs was used as the reference standard. The MRI-measured thigh volume was positively correlated with all anthropometric data, quadriceps muscle power and the up and go test as well as fat-free mass and predictive muscle mass, whereas it was negatively associated with age and walk time. In predicting thigh muscle volume, the variables of age, gender, body weight, and thigh circumference were significant predictors in the linear regression model: Muscle volume (cm3) =4226.3-42.5 × Age (year)-955.7 × gender (male=1, female=2) + 45.9 × body weight(kg) + 60.0 × thigh circumference (cm) (r2 = 0.745, P < 0.001; standard error of the estimate = 581.6 cm3). The current work provides evidence of a strong relationship between thigh muscle volume and physical function in the elderly. We also developed a prediction equation model using anthropometric measurements. This model is a simple and noninvasive method for everyday clinical practice and follow-up.

  8. Three-dimensional lateral pterygoid muscle volume: MRI analyses with insertion patterns correlation.

    PubMed

    Melke, Gabriela Sobral de Figueiredo; Costa, André Luiz Ferreira; Lopes, Sérgio Lúcio Pereira de Castro; Fuziy, Acacio; Ferreira-Santos, Rívea Inês

    2016-11-01

    We evaluated lateral pterygoid muscle volume in closed and open mouth positions in association with anterior disc displacement, effusion and abnormal articular disc shape from three-dimensional reformations of MRI. A total of 24 MRI of a sample (15 females, 9 males) aged 19-64 years (37.2 years±11.4) were assessed. Segmentation and volumetric assessment of the total, upper and lower heads of the lateral pterygoid muscle were performed using free software. The upper head of the lateral pterygoid muscle had a smaller volume than the lower head at both sides, in the closed- and open-mouth positions. In the open-mouth position, individuals with a subdivided upper head, where one component was inserted in the articular disc and another in the mandibular head, displayed a significantly larger volume of the upper head compared to individuals who had a single attachment to the articular disc (p=0.0130). The lateral pterygoid muscle has different volumes in the closed- and open-mouth positions. Gender affected muscle volume, specifically the upper head component. Insertion type in the upper head also seemed to affect muscle volume.

  9. Plantar flexor moment arm and muscle volume predict torque-generating capacity in young men.

    PubMed

    Baxter, Josh R; Piazza, Stephen J

    2014-03-01

    Muscle volume is known to correlate with maximal joint torque in humans, but the role of muscle moment arm in determining maximal torque is less clear. Moderate correlations have been reported between maximal isometric knee extensor torque and knee extensor moment arm, but no such observations have been made for the ankle joint. It has been suggested that smaller muscle moment arms may enhance force generation at high rates of joint rotation, but this has not yet been observed for ankle muscles in vivo. The purpose of the present study was to correlate plantar flexor moment arm and plantar flexor muscle volume with maximal plantar flexor torque measured at different rates of plantar flexion. Magnetic resonance imaging was used to quantify the plantar flexor moment arm and muscle volume of the posterior compartment in 20 healthy young men. Maximal plantar flexor torque was measured isometrically and at three plantar flexion speeds using an isokinetic dynamometer. Plantar flexor torque was significantly correlated with muscle volume (0.222 < R(2) < 0.322) and with muscle moment arm at each speed (0.323 < R(2) < 0.494). While muscle volume was strongly correlated with body mass and stature, moment arm was not. The slope of the torque-moment arm regression line decreased as the rate of joint rotation increased, indicating that subjects with small moment arms experienced smaller reductions in torque at high speeds. The findings of this study suggest that plantar flexor moment arm is a determinant of joint strength that is at least as important as muscle size.

  10. Inward Flux of Lactate- through Monocarboxylate Transporters Contributes to Regulatory Volume Increase in Mouse Muscle Fibres

    PubMed Central

    Lindinger, Michael I.; Leung, Matthew J.; Hawke, Thomas J.

    2013-01-01

    Mouse and rat skeletal muscles are capable of a regulatory volume increase (RVI) after they shrink (volume loss resultant from exposure to solutions of increased osmolarity) and that this RVI occurs mainly by a Na-K-Cl-Cotransporter (NKCC) - dependent mechanism. With high-intensity exercise, increased extracellular osmolarity is accompanied by large increases in extracellular [lactate-]. We hypothesized that large increases in [lactate-] and osmolarity augment the NKCC-dependent RVI response observed with a NaCl (or sucrose) - induced increase in osmolarity alone; a response that is dependent on lactate- influx through monocarboxylate transporters (MCTs). Single mouse muscle fibres were isolated and visualized under light microscopy under varying osmolar conditions. When solution osmolarity was increased by adding NaLac by 30 or 60 mM, fibres lost significantly less volume and regained volume sooner compared to when NaCl was used. Phloretin (MCT1 inhibitor) accentuated the volume loss compared to both NaLac controls, supporting a role for MCT1 in the RVI response in the presence of elevated [lactate-]. Inhibition of MCT4 (with pCMBS) resulted in a volume loss, intermediate to that seen with phloretin and NaLac controls. Bumetanide (NKCC inhibitor), in combination with pCMBS, reduced the magnitude of volume loss, but volume recovery was complete. While combined phloretin-bumetanide also reduced the magnitude of the volume loss, it also largely abolished the cell volume recovery. In conclusion, RVI in skeletal muscle exposed to raised tonicity and [lactate-] is facilitated by inward flux of solute by NKCC- and MCT1-dependent mechanisms. This work demonstrates evidence of a RVI response in skeletal muscle that is facilitated by inward flux of solute by MCT-dependent mechanisms. These findings further expand our understanding of the capacities for skeletal muscle to volume regulate, particularly in instances of raised tonicity and lactate- concentrations, as occurs

  11. Inward flux of lactate⁻ through monocarboxylate transporters contributes to regulatory volume increase in mouse muscle fibres.

    PubMed

    Lindinger, Michael I; Leung, Matthew J; Hawke, Thomas J

    2013-01-01

    Mouse and rat skeletal muscles are capable of a regulatory volume increase (RVI) after they shrink (volume loss resultant from exposure to solutions of increased osmolarity) and that this RVI occurs mainly by a Na-K-Cl-Cotransporter (NKCC)-dependent mechanism. With high-intensity exercise, increased extracellular osmolarity is accompanied by large increases in extracellular [lactate⁻]. We hypothesized that large increases in [lactate⁻] and osmolarity augment the NKCC-dependent RVI response observed with a NaCl (or sucrose)-induced increase in osmolarity alone; a response that is dependent on lactate⁻ influx through monocarboxylate transporters (MCTs). Single mouse muscle fibres were isolated and visualized under light microscopy under varying osmolar conditions. When solution osmolarity was increased by adding NaLac by 30 or 60 mM, fibres lost significantly less volume and regained volume sooner compared to when NaCl was used. Phloretin (MCT1 inhibitor) accentuated the volume loss compared to both NaLac controls, supporting a role for MCT1 in the RVI response in the presence of elevated [lactate⁻]. Inhibition of MCT4 (with pCMBS) resulted in a volume loss, intermediate to that seen with phloretin and NaLac controls. Bumetanide (NKCC inhibitor), in combination with pCMBS, reduced the magnitude of volume loss, but volume recovery was complete. While combined phloretin-bumetanide also reduced the magnitude of the volume loss, it also largely abolished the cell volume recovery. In conclusion, RVI in skeletal muscle exposed to raised tonicity and [lactate⁻] is facilitated by inward flux of solute by NKCC- and MCT1-dependent mechanisms. This work demonstrates evidence of a RVI response in skeletal muscle that is facilitated by inward flux of solute by MCT-dependent mechanisms. These findings further expand our understanding of the capacities for skeletal muscle to volume regulate, particularly in instances of raised tonicity and lactate⁻ concentrations, as

  12. Influences of swallowing volume and viscosity on regulation of levator veli palatini muscle activity during swallowing.

    PubMed

    Okuno, K; Tachimura, T; Sakai, T

    2013-09-01

    This study examined the aspect of the regulation of velum movement in the transition from the oral to pharyngeal phases of swallowing in relation to changes in the swallowing volume and viscosity by means of measurment of levator veli palatini muscle activity. The subjects were nine normal adults, ranging in age from 24 to 30 years. The swallowing volume was set at 1/4, 1/2 and 1 volume of the optimum volume of green tea for swallowing determined in each subject, and the viscosity was adjusted to 0, 2·0 and 4·6 Pa·s by mixing with thickener. Nine test foods were prepared in total. The electromyographic activity of the levator veli palatini muscle was monitored using bipolar hooked wire electrodes. The levator veli palatini muscle activity was defined as the integrated electromyographic wave. The mean in swallowing each test food was determined in each subject. The levator veli palatini muscle activity increased with the swallowing volume for all subjects (P < 0·05) and decreased inversely with the viscosity for six subjects (P < 0·05), but no change with the increase in the viscosity was noted for three subjects. This study clarified the aspect of the regulation of velar movement with regard to the involvement of the levator veli palatini muscle in swallowing activity with changes in the swallowing volume and viscosity.

  13. Blanket comparison and selection study. Volume II

    SciTech Connect

    Not Available

    1983-10-01

    This volume contains extensive data for the following chapters: (1) solid breeder tritium recovery, (2) solid breeder blanket designs, (3) alternate blanket concept screening, and (4) safety analysis. The following appendices are also included: (1) blanket design guidelines, (2) power conversion systems, (3) helium-cooled, vanadium alloy structure blanket design, (4) high wall loading study, and (5) molten salt safety studies. (MOW)

  14. Relationship between quadriceps femoris muscle volume and muscle torque at least 18 months after anterior cruciate ligament reconstruction.

    PubMed

    Konishi, Y; Oda, T; Tsukazaki, S; Kinugasa, R; Fukubayashi, T

    2012-12-01

    The purpose of this study was to evaluate motor unit recruitment in the quadriceps femoris (QF) after anterior cruciate ligament (ACL) rupture and repair. Subjects included 24 patients at ≥ 18 months after ACL reconstruction and 22 control subjects with no history of knee injury. A series of cross-sectional magnetic resonance images were obtained to compare the QF of patients' injured side with that of their uninjured sides and that of uninjured control subjects. Muscle torque per muscle volume was calculated as isokinetic peak torque divided by QF muscle volume (cm(3)). The mean muscle torque per unit volume of the injured side of patients was not significantly different from that of the uninjured side or control subjects (one-way ANOVA) Results of the present study were contrary to the results of a previous study that evaluated patients at ≤ 12 months after ACL reconstruction. The present study found that high-threshold motor unit recruitment was restored at ≥ 18 months after ACL reconstruction. Thus, clinicians must develop techniques that increase the recruitment of high-threshold motor units in the QF from the period immediately after the injury until approximately 18 months after ACL reconstruction. © 2011 John Wiley & Sons A/S.

  15. Skeletal Muscle Apoptotic Signaling Predicts Thigh Muscle Volume and Gait Speed in Community-Dwelling Older Persons: An Exploratory Study

    PubMed Central

    Marzetti, Emanuele; Lees, Hazel A.; Manini, Todd M.; Buford, Thomas W.; Aranda, Juan M.; Calvani, Riccardo; Capuani, Giorgio; Marsiske, Michael; Lott, Donovan J.; Vandenborne, Krista; Bernabei, Roberto; Pahor, Marco; Leeuwenburgh, Christiaan; Wohlgemuth, Stephanie E.

    2012-01-01

    Background Preclinical studies strongly suggest that accelerated apoptosis in skeletal myocytes may be involved in the pathogenesis of sarcopenia. However, evidence in humans is sparse. In the present study, we investigated whether apoptotic signaling in the skeletal muscle was associated with indices of muscle mass and function in older persons. Methodology/Principal Findings Community-dwelling older adults were categorized into high-functioning (HF) or low-functioning (LF) groups according to their short physical performance battery (SPPB) summary score. Participants underwent an isokinetic knee extensor strength test and 3-dimensional magnetic resonance imaging of the thigh. Vastus lateralis muscle samples were obtained by percutaneous needle biopsy and assayed for the expression of a set of apoptotic signaling proteins. Age, sex, number of comorbid conditions and medications as well as knee extensor strength were not different between groups. HF participants displayed greater thigh muscle volume compared with LF persons. Multivariate partial least squares (PLS) regressions showed significant correlations between caspase-dependent apoptotic signaling proteins and the muscular percentage of thigh volume (R2 = 0.78; Q2 = 0.61) as well as gait speed (R2 = 0.81; Q2 = 0.56). Significant variables in the PLS model of percent muscle volume were active caspase-8, cleaved caspase-3, cytosolic cytochrome c and mitochondrial Bak. The regression model of gait speed was mainly described by cleaved caspase-3 and mitochondrial Bax and Bak. PLS predictive apoptotic variables did not differ between functional groups. No correlation was determined between apoptotic signaling proteins and muscle strength or quality (strength per unit volume). Conclusions/Significance Data from this exploratory study show for the first time that apoptotic signaling is correlated with indices of muscle mass and function in a cohort of community-dwelling older persons. Future larger

  16. NMR imaging estimates of muscle volume and intramuscular fat infiltration in the thigh: variations with muscle, gender, and age.

    PubMed

    Hogrel, Jean-Yves; Barnouin, Yoann; Azzabou, Noura; Butler-Browne, Gillian; Voit, Thomas; Moraux, Amélie; Leroux, Gaëlle; Behin, Anthony; McPhee, Jamie S; Carlier, Pierre G

    2015-06-01

    Muscle mass is particularly relevant to follow during aging, owing to its link with physical performance and autonomy. The objectives of this work were to assess muscle volume (MV) and intramuscular fat (IMF) for all the muscles of the thigh in a large population of young and elderly healthy individuals using magnetic resonance imaging (MRI) to test the effect of gender and age on MV and IMF and to determine the best representative slice for the estimation of MV and IMF. The study enrolled 105 healthy young (range 20-30 years) and older (range 70-80 years) subjects. MRI scans were acquired along the femur length using a three-dimension three-point Dixon proton density-weighted gradient echo sequence. MV and IMF were estimated from all the slices. The effects of age and gender on MV and IMF were assessed. Predictive equations for MV and IMF were established using a single slice at various femur levels for each muscle in order to reduce the analysis process. MV was decreased with aging in both genders, particularly in the quadriceps femoris. IMF was largely increased with aging in men and, to a lesser extent, in women. Percentages of MV decrease and IMF increase with aging varied according to the muscle. Predictive equations to predict MV and IMF from single slices are provided and were validated. This study is the first one to provide muscle volume and intramuscular fat infiltration in all the muscles of the thigh in a large population of young and elderly healthy subjects.

  17. Quantitative assessment of fatty infiltration and muscle volume of the rotator cuff muscles using 3-dimensional 2-point Dixon magnetic resonance imaging.

    PubMed

    Matsumura, Noboru; Oguro, Sota; Okuda, Shigeo; Jinzaki, Masahiro; Matsumoto, Morio; Nakamura, Masaya; Nagura, Takeo

    2017-10-01

    In patients with rotator cuff tears, muscle degeneration is known to be a predictor of irreparable tears and poor outcomes after surgical repair. Fatty infiltration and volume of the whole muscles constituting the rotator cuff were quantitatively assessed using 3-dimensional 2-point Dixon magnetic resonance imaging. Ten shoulders with a partial-thickness tear, 10 shoulders with an isolated supraspinatus tear, and 10 shoulders with a massive tear involving supraspinatus and infraspinatus were compared with 10 control shoulders after matching age and sex. With segmentation of muscle boundaries, the fat fraction value and the volume of the whole rotator cuff muscles were computed. After reliabilities were determined, differences in fat fraction, muscle volume, and fat-free muscle volume were evaluated. Intra-rater and inter-rater reliabilities were regarded as excellent for fat fraction and muscle volume. Tendon rupture adversely increased the fat fraction value of the respective rotator cuff muscle (P < .002). In the massive tear group, muscle volume was significantly decreased in the infraspinatus (P = .035) and increased in the teres minor (P = .039). With subtraction of fat volume, a significant decrease of fat-free volume of the supraspinatus muscle became apparent with a massive tear (P = .003). Three-dimensional measurement could evaluate fatty infiltration and muscular volume with excellent reliabilities. The present study showed that chronic rupture of the tendon adversely increases the fat fraction of the respective muscle and indicates that the residual capacity of the rotator cuff muscles might be overestimated in patients with severe fatty infiltration. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  18. Effect of extracellular osmolality on cell volume and resting metabolism in mammalian skeletal muscle.

    PubMed

    Antolic, AnaMaria; Harrison, Rosemarie; Farlinger, Chris; Cermak, Naomi M; Peters, Sandra J; LeBlanc, Paul; Roy, Brian D

    2007-05-01

    The purpose of the present investigation was to establish an in vitro mammalian skeletal muscle model to study acute alterations in resting skeletal muscle cell volume. Isolated, whole muscles [soleus and extensor digitorum longus (EDL)] were dissected from Long-Evans rats and incubated for 60 min in Sigma medium 199 (1 g of resting tension, bubbled with 95% O(2)-5% O(2), 30 +/- 2 degrees C, and pH 7.4). Medium osmolality was altered to simulate hyposmotic (190 +/- 10 mmol/kg) or hyperosmotic conditions (400 +/- 10 mmol/kg), whereas an isosmotic condition (290 +/- 10 mmol/kg) served as a control. After incubation, relative water content of the muscle decreased with hyperosmotic and increased with hyposmotic condition in both muscle types (P < 0.05). The cross-sectional area of soleus type I and type II fibers increased (P < 0.05) in hyposmotic, whereas hyperosmotic exposure led to no detectable changes. The EDL type II fiber area decreased in the hyperosmotic condition and increased after hyposmotic exposure, whereas no change was observed in EDL type I fibers. Furthermore, exposure to the hyperosmotic condition in both muscle types resulted in decreased muscle ATP and phosphocreatine (P < 0.05) contents and increased creatine and lactate contents (P < 0.05) compared with control and hyposmotic conditions. This isolated skeletal muscle model proved viable and demonstrated that altering extracellular osmolality could cause acute alterations in muscle water content and resting muscle metabolism.

  19. Diminished Foot and Ankle Muscle Volumes in Young Adults With Chronic Ankle Instability

    PubMed Central

    Feger, Mark A.; Snell, Shannon; Handsfield, Geoffrey G.; Blemker, Silvia S.; Wombacher, Emily; Fry, Rachel; Hart, Joseph M.; Saliba, Susan A.; Park, Joseph S.; Hertel, Jay

    2016-01-01

    Background: Patients with chronic ankle instability (CAI) have demonstrated altered neuromuscular function and decreased muscle strength when compared with healthy counterparts without a history of ankle sprain. Up to this point, muscle volumes have not been analyzed in patients with CAI to determine whether deficits in muscle size are present following recurrent sprain. Purpose: To analyze intrinsic and extrinsic foot and ankle muscle volumes and 4-way ankle strength in young adults with and without CAI. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Five patients with CAI (mean age, 23.0 ± 4 years; 1 male, 4 females) and 5 healthy controls (mean age, 23.8 ± 4.5 years; 1 male, 4 females) volunteered for this study. Novel fast-acquisition magnetic resonance imaging (MRI) was used to scan from above the femoral condyles through the foot and ankle. The perimeter of each muscle was outlined on each axial slice and then the 2-dimensional area was multiplied by the slice thickness (5 mm) to calculate the muscle volume. Plantar flexion, dorsiflexion, inversion, and eversion isometric strength were measured using a handheld dynamometer. Patients with CAI were compared with healthy controls on all measures of muscle volume and strength. Extrinsic muscle volumes of patients with CAI were also compared with a normative database of healthy controls (n = 24) by calculating z scores for each muscle individually for each CAI subject. Results: The CAI group had smaller total shank, superficial posterior compartment, soleus, adductor hallucis obliqus, and flexor hallucis brevis muscle volumes compared with healthy controls as indicated by group means and associated 90% CIs that did not overlap. Cohen d effect sizes for the significant group differences were all large and ranged from 1.46 to 3.52, with 90% CIs that did not cross zero. The CAI group had lower eversion, dorsiflexion, and 4-way composite ankle strength, all with group means and associated 90

  20. Resistance exercise-induced fluid shifts: change in active muscle size and plasma volume

    NASA Technical Reports Server (NTRS)

    Ploutz-Snyder, L. L.; Convertino, V. A.; Dudley, G. A.

    1995-01-01

    The purpose of this study was to test the hypothesis that the reduction in plasma volume (PV) induced by resistance exercise reflects fluid loss to the extravascular space and subsequently selective increase in cross-sectional area (CSA) of active but not inactive skeletal muscle. We compared changes in active and inactive muscle CSA and PV after barbell squat exercise. Magnetic resonance imaging (MRI) was used to quantify muscle involvement in exercise and to determine CSA of muscle groups or individual muscles [vasti (VS), adductor (Add), hamstring (Ham), and rectus femoris (RF)]. Muscle involvement in exercise was determined using exercise-induced contrast shift in spin-spin relaxation time (T2)-weighted MR images immediately postexercise. Alterations in muscle size were based on the mean CSA of individual slices. Hematocrit, hemoglobin, and Evans blue dye were used to estimate changes in PV. Muscle CSA and PV data were obtained preexercise and immediately postexercise and 15 and 45 min thereafter. A hierarchy of muscle involvement in exercise was found such that VS > Add > Ham > RF, with the Ham and RF showing essentially no involvement. CSA of the VS and Add muscle groups were increased 10 and 5%, respectively, immediately after exercise in each thigh with no changes in Ham and RF CSA. PV was decreased 22% immediately following exercise. The absolute loss of PV was correlated (r2 = 0.75) with absolute increase in muscle CSA immediately postexercise, supporting the notion that increased muscle size after resistance exercise reflects primarily fluid movement from the vascular space into active but not inactive muscle.

  1. Resistance exercise-induced fluid shifts: change in active muscle size and plasma volume

    NASA Technical Reports Server (NTRS)

    Ploutz-Snyder, L. L.; Convertino, V. A.; Dudley, G. A.

    1995-01-01

    The purpose of this study was to test the hypothesis that the reduction in plasma volume (PV) induced by resistance exercise reflects fluid loss to the extravascular space and subsequently selective increase in cross-sectional area (CSA) of active but not inactive skeletal muscle. We compared changes in active and inactive muscle CSA and PV after barbell squat exercise. Magnetic resonance imaging (MRI) was used to quantify muscle involvement in exercise and to determine CSA of muscle groups or individual muscles [vasti (VS), adductor (Add), hamstring (Ham), and rectus femoris (RF)]. Muscle involvement in exercise was determined using exercise-induced contrast shift in spin-spin relaxation time (T2)-weighted MR images immediately postexercise. Alterations in muscle size were based on the mean CSA of individual slices. Hematocrit, hemoglobin, and Evans blue dye were used to estimate changes in PV. Muscle CSA and PV data were obtained preexercise and immediately postexercise and 15 and 45 min thereafter. A hierarchy of muscle involvement in exercise was found such that VS > Add > Ham > RF, with the Ham and RF showing essentially no involvement. CSA of the VS and Add muscle groups were increased 10 and 5%, respectively, immediately after exercise in each thigh with no changes in Ham and RF CSA. PV was decreased 22% immediately following exercise. The absolute loss of PV was correlated (r2 = 0.75) with absolute increase in muscle CSA immediately postexercise, supporting the notion that increased muscle size after resistance exercise reflects primarily fluid movement from the vascular space into active but not inactive muscle.

  2. Collision and containment detection between biomechanically based eye muscle volumes.

    PubMed

    Santana Sosa, Graciela; Kaltofen, Thomas

    2011-01-01

    Collision and containment detection between three-dimensional objects is a common requirement in simulation systems. However, few solutions exist when exclusively working with deformable bodies. In our ophthalmologic diagnostic software system, the extraocular eye muscles are represented by surface models, which have been reconstructed from magnetic resonance images. Those models are projected onto the muscle paths calculated by the system's biomechanical model. Due to this projection collisions occur. For their detection, three approaches have been implemented, which we present in this paper: one based on image-space techniques using OpenGL, one based on the Bullet physics library and one using an optimized space-array data structure together with software rendering. Finally, an outlook on a possible response to the detected collisions is given.

  3. Diaphragm curvature modulates the relationship between muscle shortening and volume displacement.

    PubMed

    Greybeck, Brad J; Wettergreen, Matthew; Hubmayr, Rolf D; Boriek, Aladin M

    2011-07-01

    During physiological spontaneous breathing maneuvers, the diaphragm displaces volume while maintaining curvature. However, with maximal diaphragm activation, curvature decreases sharply. We tested the hypotheses that the relationship between diaphragm muscle shortening and volume displacement (VD) is nonlinear and that curvature is a determinant of such a relationship. Radiopaque markers were surgically placed on three neighboring muscle fibers in the midcostal region of the diaphragm in six dogs. The three-dimensional locations were determined using biplanar fluoroscopy and diaphragm VD, curvature, and muscle shortening were computed in the prone and supine postures during spontaneous breathing (SB), spontaneous inspiration efforts after airway occlusion at lung volumes ranging from functional residual capacity (FRC) to total lung capacity, and during bilateral maximal phrenic nerve stimulation at those same lung volumes. In supine dogs, diaphragm VD was approximately two- to three-fold greater during maximal phrenic nerve stimulation than during SB. The contribution of muscle shortening to VD nonlinearly increases with level of diaphragm activation independent of posture. During submaximal diaphragm activation, the contribution is essentially linear due to constancy of diaphragm curvature in both the prone and supine posture. However, the sudden loss of curvature during maximal bilateral phrenic nerve stimulation at muscle shortening values greater than 40% (ΔL/L(FRC)) causes a nonlinear increase in the contribution of muscle shortening to diaphragm VD, which is concomitant with a nonlinear change in diaphragm curvature. We conclude that the nonlinear relationship between diaphragm muscle shortening and its VD is, in part, due to a loss of its curvature at extreme muscle shortening.

  4. Lymphedema Leads to Fat Deposition in Muscle and Decreased Muscle/Water Volume After Liposuction: A Magnetic Resonance Imaging Study.

    PubMed

    Hoffner, Mattias; Peterson, Pernilla; Månsson, Sven; Brorson, Håkan

    2017-09-28

    Lymphedema leads to adipose tissue deposition. Water-fat magnetic resonance imaging (MRI) can quantify and localize fat and water. The presence of excess fat and excess water/muscle in the subfascial compartment of the lymphedematous limb has not been investigated before. The aim of this study was to investigate epifascial and subfascial fat and water contents in patients with chronic lymphedema before and after liposuction. Seven patients with arm lymphedema and six with leg lymphedema were operated on. The limbs were examined with water-fat MRI before liposuction (baseline) and at five time points. Complete reduction of the excess limb volumes was achieved. The excess epifascial fat was evident in the edematous limbs and a drop was seen following surgery. There were differences in excess water at all time points. At 1 year there was a decrease in excess water. Excess subfascial fat was seen in the edematous limbs at all time points. Subfascial excess water/muscle did not show any differences after surgery. However, starting from 3 months there was less subfascial water/muscle compared with baseline. Subfascial fat in the lymphedematous limbs did not change. In contrast, the water in the subfascial compartment was reduced over time, which may represent a decrease of muscle volume after treatment due to less mechanical load after liposuction. Using water-fat MRI-based fat quantification, the fat and water contents may be quantified and localized in the various compartments in lymphedema.

  5. Volume measurements of individual muscles in human quadriceps femoris using atlas-based segmentation approaches.

    PubMed

    Le Troter, Arnaud; Fouré, Alexandre; Guye, Maxime; Confort-Gouny, Sylviane; Mattei, Jean-Pierre; Gondin, Julien; Salort-Campana, Emmanuelle; Bendahan, David

    2016-04-01

    Atlas-based segmentation is a powerful method for automatic structural segmentation of several sub-structures in many organs. However, such an approach has been very scarcely used in the context of muscle segmentation, and so far no study has assessed such a method for the automatic delineation of individual muscles of the quadriceps femoris (QF). In the present study, we have evaluated a fully automated multi-atlas method and a semi-automated single-atlas method for the segmentation and volume quantification of the four muscles of the QF and for the QF as a whole. The study was conducted in 32 young healthy males, using high-resolution magnetic resonance images (MRI) of the thigh. The multi-atlas-based segmentation method was conducted in 25 subjects. Different non-linear registration approaches based on free-form deformable (FFD) and symmetric diffeomorphic normalization algorithms (SyN) were assessed. Optimal parameters of two fusion methods, i.e., STAPLE and STEPS, were determined on the basis of the highest Dice similarity index (DSI) considering manual segmentation (MSeg) as the ground truth. Validation and reproducibility of this pipeline were determined using another MRI dataset recorded in seven healthy male subjects on the basis of additional metrics such as the muscle volume similarity values, intraclass coefficient, and coefficient of variation. Both non-linear registration methods (FFD and SyN) were also evaluated as part of a single-atlas strategy in order to assess longitudinal muscle volume measurements. The multi- and the single-atlas approaches were compared for the segmentation and the volume quantification of the four muscles of the QF and for the QF as a whole. Considering each muscle of the QF, the DSI of the multi-atlas-based approach was high 0.87 ± 0.11 and the best results were obtained with the combination of two deformation fields resulting from the SyN registration method and the STEPS fusion algorithm. The optimal variables for FFD

  6. Ground and Space Radar Volume Matching and Comparison Software

    NASA Technical Reports Server (NTRS)

    Morris, Kenneth; Schwaller, Mathew

    2010-01-01

    This software enables easy comparison of ground- and space-based radar observations. The software was initially designed to compare ground radar reflectivity from operational, ground based Sand C-band meteorological radars with comparable measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite s Precipitation Radar (PR) instrument. The software is also applicable to other ground-based and space-based radars. The ground and space radar volume matching and comparison software was developed in response to requirements defined by the Ground Validation System (GVS) of Goddard s Global Precipitation Mission (GPM) project. This software innovation is specifically concerned with simplifying the comparison of ground- and spacebased radar measurements for the purpose of GPM algorithm and data product validation. This software is unique in that it provides an operational environment to routinely create comparison products, and uses a direct geometric approach to derive common volumes of space- and ground-based radar data. In this approach, spatially coincident volumes are defined by the intersection of individual space-based Precipitation Radar rays with the each of the conical elevation sweeps of the ground radar. Thus, the resampled volume elements of the space and ground radar reflectivity can be directly compared to one another.

  7. Comparison of Standing Volume Estimates Using Optical Dendrometers

    Treesearch

    Neil A. Clark; Stanley J. Zarnoch; Alexander Clark; Gregory A. Reams

    2001-01-01

    This study compared height and diameter measurements and volume estimates on 20 hardwood and 20 softwood stems using traditional optical dendrometers, an experimental camera instrument, and mechanical calipers. Multiple comparison tests showed significant differences among the means for lower stem diameters when the camera was used. There were no significant...

  8. Comparison of standing volume estimates using optical dendrometers

    Treesearch

    Neil A. Clark; Stanley J. Zarnoch; Alexander Clark; Gregory A. Reams

    2001-01-01

    This study compared height and diameter measurements and volume estimates on 20 hardwood and 20 softwood stems using traditional optical dendrometers, an experimental camera instrument, and mechanical calipers. Multiple comparison tests showed significant differences among the means for lower stem diameters when the camera was used. There were no significant...

  9. Relationships of ultrasound measures of intrinsic foot muscle cross-sectional area and muscle volume with maximum toe flexor muscle strength and physical performance in young adults

    PubMed Central

    Abe, Takashi; Tayashiki, Kota; Nakatani, Miyuki; Watanabe, Hironori

    2016-01-01

    [Purpose] To investigate the relationships between toe flexor muscle strength with (TFS-5-toes) and without (TFS-4-toes) the contribution of the great toe, anatomical and physiological muscle cross-sectional areas (CSA) of intrinsic toe flexor muscle and physical performance were measured. [Subjects] Seventeen men (82% sports-active) and 17 women (47% sports-active), aged 20 to 35 years, volunteered. [Methods] Anatomical CSA was measured in two intrinsic toe flexor muscles (flexor digitorum brevis [FDB] and abductor hallucis) by ultrasound. Muscle volume and muscle length of the FDB were also estimated, and physiological CSA was calculated. [Results] Both TFS-5-toes and TFS-4-toes correlated positively with walking speed in men (r=0.584 and r=0.553, respectively) and women (r=0.748 and r=0.533, respectively). Physiological CSA of the FDB was significantly correlated with TFS-5-toes (r=0.748) and TFS-4-toes (r=0.573) in women. In men, physiological CSA of the FDB correlated positively with TFS-4-toes (r=0.536), but not with TFS-5-toes (r=0.333). [Conclusion] Our results indicate that physiological CSA of the FDB is moderately associated with TFS-4-toes while toe flexor strength correlates with walking performance. PMID:26957721

  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. Effects of changes in cell volume on the rates of glutamine and alanine release from rat skeletal muscle in vitro.

    PubMed

    Parry-Billings, M; Bevan, S J; Opara, E; Newsholme, E A

    1991-06-01

    The effect of changes in cell volume on the rates of release of glutamine and alanine from muscle and on the concentrations of these amino acids in muscle were investigated by using an isolated preparation of rat skeletal muscle incubated in the presence of hypo- and hyper-osmotic media. Changes in cell volume were associated with changes in the rates of release of glutamine and alanine from muscle: incubation in hypo-osmotic medium decreased the rates of release of glutamine and alanine, and incubation in hyperosmotic medium increased these rates. These changes were rapidly reversed by a change in osmoticity of the medium. Despite marked changes in cell volume, the concentrations of these amino acids in muscle were maintained. It is suggested that cell volume may play a role in the regulation of amino acid metabolism in skeletal muscle.

  12. Comparison of the protein-synthesizing machinery in the skeletal muscle of normal and dystrophic Bar Harbor mice.

    PubMed

    Watts, D C; Reid, J D

    1969-11-01

    1. Although the total weight of leg muscle increased with the age of a normal mouse the DNA and RNA content per leg did not change significantly. 2. The weight of leg muscle from a dystrophic mouse was only about 45% of that from a normal mouse but the DNA and RNA contents were the same and hence similar DNA/RNA ratios were obtained. 3. The total ribosome contents of normal and dystrophic mice were the same on a whole-leg basis, and for both the free ribosomes were about 60% of the total. However, comparison with similar data from liver suggested that some loss of ribosomes occurred during the isolation procedure. 4. The polyribosome patterns obtained by density-gradient centrifugation were the same for normal and dystrophic muscle, and comparable polyribosome fractions of different sizes obtained from such gradients had similar capacities for the incorporation of radioactive amino acids in a standard protein-synthesizing system. 5. By using a standard protein-synthesizing system with normal polyribosomes similar extents of incorporation were found with normal- or dystrophic-muscle pH5 fraction or partially purified transfer RNA preparation. 6. It is concluded that there is no absolute difference between the protein-synthesizing systems of normal and dystrophic mouse muscle and that the observed apparent differences result from concentration differences caused by changes in muscle volume. 7. A possible cause of the failure of dystrophic muscle to resynthesize myofibrils is also suggested.

  13. Respiratory muscle force and lung volume changes in a population of children with sickle cell disease.

    PubMed

    Ong, Bruce A; Caboot, Jason; Jawad, Abbas; McDonough, Joseph; Jackson, Tannoa; Arens, Raanan; Marcus, Carole L; Smith-Whitley, Kim; Mason, Thornton B A; Ohene-Frempong, Kwaku; Allen, Julian L

    2013-10-01

    Sickle cell disease (SCD) is a disorder known to impact the respiratory system. We sought to identify respiratory muscle force and lung volume relationships in a paediatric SCD population. Thirty-four SCD-SS subjects underwent pulmonary function testing. Height, weight, age, and gender-adjusted percent predicted maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) values were compared to spirometry and lung volumes. Statistical analyses were performed using Pearson's correlation coefficient and paired two-tailed t-test. The mean ± standard deviation (SD) MIP and MEP was 69·6 ± 31·6 cm H2 O and 66·9 ± 22·9 cm H2 O, respectively, and mean ± SD percent predicted MIP (101·3 ± 45·9) exceeded MEP (72·1 ± 26·0) (P = 0·002). MIP correlated with forced vital capacity (FVC; r = 0·51, P = 0·001) and TLC (r = 0·54, P < 0·0001). MEP also correlated with FVC (r = 0·43, P = 0·011) and total lung capacity (TLC; r = 0·42, P = 0·013). Pearson's correlation coefficient testing yielded relationships between MIP and MEP (r = 0·64, P < 0·0001). SCD-SS patients showed correlations between respiratory muscle force and lung volume, and reduced percent predicted expiratory muscle force compared to inspiratory muscle force. Respiratory muscle strength may affect lung volumes in these patients, and expiratory muscles may be more susceptible than the diaphragm to SCD-induced vaso-occlusive damage. © 2013 John Wiley & Sons Ltd.

  14. Comparison of peak muscle power between Brazilian and French girls.

    PubMed

    Nanci Maria, França; Eric, Doré; Mario, Bedu; Emmanuel, Van Praagh

    2002-01-01

    This study examined the muscle power of Brazilian circumpubertal girls and extended the analysis to a cross-cultural dimension. A total of 462 children, 123 Brazilian girls and 339 French girls, 9-18 years, participated in this investigation. Anthropometric data included body mass (BM), height, skinfold thicknesses, and estimated lean leg volume (LLV). All subjects completed a physical activity questionnaire. Cycling peak power was measured including the flywheel inertia of the device (CPPi). Brazilian girls self-assessed their maturation using pubic hair development. CPPi and optimal velocity (v(opt) = velocity at CPPi) increased with stages of puberty. A multiple stepwise regression with anthropometric variables as explanatory factors showed only LLV and age explaining the variance of CPPi (R2 = 0.40, P < 0.001). Therefore, 60% of the variance of CPPi in Brazilian girls was related to undetermined qualitative individual factors, which may be related to cycling skill. Even when normalized for anthropometric variables, the anaerobic performance (CPPi and v(opt)) of Brazilian girls was significantly lower than a cohort of French girls. The latter demonstrated a high participation in sport and training activities, while 50% of the Brazilian girls had only physical education classes in the form of regular physical activity. Moreover, most of the Brazilian girls demonstrated an ineffective sprint cycling skill. The data suggest that motor learning is an important issue in muscle power assessment and might, therefore, partially explain peak power differences in Brazilian compared with French girls.

  15. Volume-pressure relationship (compliance) of interstitium in dog skin and muscle

    SciTech Connect

    Wiig, H.; Reed, R.K. )

    1987-08-01

    The relationship between changes in interstitial fluid volume (IFV) and pressure (IFP) during over- and dehydration was estimated in hindlimb skin and skeletal muscle of 17 dogs. IFV was measured as the extravascular distribution volume of {sup 51}Cr-EDTA after nephrectomy and IFP with micropipettes, wick-in-needle technique (WIN), and perforated capsules. Control IFP (micropipettes) averaged {minus}1.7 {plus minus} 0.5 and 0.0 {plus minus} 1.0 mmHg in skin and muscle, respectively, not different from corresponding WIN and capsule pressures in subcutis. Control IFV was 0.93 {plus minus} 0.34 and 0.42 {plus minus} 0.11 ml/g dry wt in skin and muscle, respectively. Peritoneal dialysis with 20% glucose reduced IFV by 27% in skin and by 44% in muscle, whereas micropipette IFP fell gradually by {approximately} 4 mmHg in skin and muscle. Compliance during dehydration was 7.6 and 12.5% change in IFV per millimeter Hg fall in IFP (micropipettes) in skin and muscle, respectively, whereas compliance in subcutis based on perforated capsule pressure was 2.0% change in IFV per millimeter Hg. The maximal increase in IFP during overhydration was {approximately}2 mmHg in both skin and muscle. Skin and muscle compliance in dogs did not differ significantly from that of rats and cats. The authors conclude that the difference in compliance among previous studies mainly results from different methods for IFP measurement but is probably also influenced by the state of hydration before altering IFV.

  16. Effects of inspiratory muscle training on lung volumes, respiratory muscle strength, and quality of life in patients with ataxia telangiectasia.

    PubMed

    Félix, Erika; Gimenes, Ana Cristina; Costa-Carvalho, Beatriz Tavares

    2014-03-01

    Ataxia telangiectasia (AT) is a genetic syndrome caused by a mutation of chromosome 11. The clinical features are cerebellar ataxia, telangiectasia, and progressive loss of muscular coordination, including an inefficient cough secondary to progression of neurological disease. To evaluate the effects of inspiratory muscle training (IMT) on ventilation, lung volume, dyspnoea, respiratory muscle strength, and quality of life in patients with AT. A longitudinal study was conducted with 11 AT patients and nine healthy volunteers. Ventilometry, subjective sensation of dyspnoea, maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and quality of life were assessed before and after a 24-week IMT program. The IMT load used was set at 60% of the MIP, and the training was performed for 20 min daily. Patients with AT had lower height and weight and also had lower respiratory muscle strength and lung volume compared with healthy volunteers. Furthermore, patients with AT showed a significant improvement when pre- and post-IMT were compared for ventilatory pattern: Vt (476.5 ± 135 ml vs. 583.3 ± 66 ml, P = 0.015) and f (23.3 ± 6 rpm vs. 20.4 ± 4 rpm, P = 0.018), and VC (1,664 ± 463 ml/kg vs. 2,145 ± 750 ml/kg, P = 0.002). IMT also significantly improved the sensation of dyspnoea (median 0.5; minimum 0; maximum 1.0; P = 0.022) and respiratory muscle strength: MIP (-22.2 ± 2 cmH2O vs. -38 ± 9 cmH2O, P < 0.001) and MEP (29 ± 7 cmH2O vs. 40 ± 8 cmH2O, P = 0.001). The health and vitality domains of the SF-36 also showed significant improvement (P = 0.009 and P = 0.014, respectively) post-IMT. IMT was effective in improving ventilatory pattern, lung volume, respiratory muscle strength, and the health and vitality domains for quality of life in patients with AT. IMT may be an effective adjunct therapy to drug treatment for patients with AT. © 2013 Wiley Periodicals, Inc.

  17. Comparison of coil designs for peripheral magnetic muscle stimulation

    NASA Astrophysics Data System (ADS)

    Goetz, S. M.; Herzog, H.-G.; Gattinger, N.; Gleich, B.

    2011-10-01

    The recent application of magnetic stimulation in rehabilitation is often said to solve key drawbacks of the established electrical method. Magnetic fields cause less pain, allow principally a better penetration of inhomogeneous biologic tissue and do not require skin contact. However, in most studies the evoked muscle force has been disappointing. In this paper, a comparison of a classical round circular geometry, a commercial muscle-stimulation coil and a novel design is presented, with special emphasis on the physical field properties. These systems show markedly different force responses for the same magnetic energy and highlight the enormous potential of different coil geometries. The new design resulted in a slope of the force recruiting curve being more than two and a half times higher than the other coils. The data were analyzed with respect to the underlying physical causes and field conditions. After a parameter-extraction approach, the results for the three coils span a two-dimensional space with clearly distinguishable degrees of freedom, which can be manipulated nearly separately and reflect the two main features of a field; the peak amplitude and its decay with the distance.

  18. Physiological comparison of rat muscle in body suspension and weightlessness

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.; Steffen, J. M.; Fell, R. D.; Dombrovski, J.

    1987-01-01

    Hind limb unloading is achieved with whole body suspension (WBS) and with tail suspension (TS). Comparable levels of muscle mass loss and decreases in protein levels result during one to three weeks of exposure to microgravity (microG), WBS, and TS. Losses are most apparent in soleus (S), intermediate in gastrocnemius (G) and least in extensor digigorum longus (EDL). Comparison of S and EDL type I and II fiber changes (numbers and area) after seven days of microG flight and WBS showed, in S, an increase in Type I and Type II fiber density and a decrease in area. Except for a decrease in Type I fiber density in EDL, all other parameters remained comparable. The general conclusions were that the S under microG and WBS responds in a similar manner. The EDL, for the most part, shows little change under both conditions.

  19. Comparison of methods to quantify volume during resistance exercise.

    PubMed

    McBride, Jeffrey M; McCaulley, Grant O; Cormie, Prue; Nuzzo, James L; Cavill, Michael J; Triplett, N Travis

    2009-01-01

    The purpose of this investigation was to compare 4 different methods of calculating volume when comparing resistance exercise protocols of varying intensities. Ten Appalachian State University students experienced in resistance exercise completed 3 different resistance exercise protocols on different days using a randomized, crossover design, with 1 week of rest between each protocol. The protocols included 1) hypertrophy: 4 sets of 10 repetitions in the squat at 75% of a 1-repetition maximum (1RM) (90-second rest periods); 2) strength: 11 sets of 3 repetitions at 90% 1RM (5-minute rest periods); and 3) power: 8 sets of 6 repetitions of jump squats at 0% 1RM (3-minute rest periods). The volume of resistance exercise completed during each protocol was determined with 4 different methods: 1) volume load (VL) (repetitions [no.] x external load [kg]); 2) maximum dynamic strength volume load (MDSVL) (repetitions [no.] x [body mass--shank mass (kg) + external load (kg)]); 3) time under tension (TUT) (eccentric time +milliseconds] + concentric time +milliseconds]); and 4) total work (TW) (force [N] x displacement [m]). The volumes differed significantly (p , 0.05) between hypertrophy and strength in comparison with the power protocol when VL and MDSVL were used to determine the volume of resistance exercise completed. Furthermore, significant differences in TUT existed between all 3 resistance exercise protocols. The TW calculated was not significantly different between the 3 protocols. These data imply that each method examined results in substantially different values when comparing various resistance exercise protocols involving different levels of intensity.

  20. Effects of Low Volume Aerobic Training on Muscle Desaturation During Exercise in Elderly Subjects.

    PubMed

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

    2016-01-01

    Aging enhances muscle desaturation responses due to reduced O2 supply. Even though aerobic training enhances muscle desaturation responses in young subjects, it is unclear whether the same is true in elderly subjects. Ten elderly women (age: 62±4 years) participated in 12-weeks of cycling exercise training. Training consisted of 30 min cycling exercise at the lactate threshold. The subjects exercised 15±6 sessions during training. Before and after endurance training, the subjects performed ramp cycling exercise. Muscle O2 saturation (SmO2) was measured at the vastus lateralis by near infrared spectroscopy during the exercise. There were no significant differences in SmO2 between before and after training. Nevertheless, changes in peak pulmonary O2 uptake were significantly negatively related to changes in SmO2 (r=-0.67, p<0.05) after training. Muscle desaturation was not enhanced by low volume aerobic training in this study, possibly because the training volume was too low. However, our findings suggest that aerobic training may potentially enhance muscle desaturation at peak exercise in elderly subjects.

  1. Changes in extracellular muscle volume affect heart rate and blood pressure responses to static exercise

    NASA Astrophysics Data System (ADS)

    Baum, K.; Essfeld, D.; Stegemann, J.

    To investigate the effect of μg-induced peripheral extracellular fluid reductions on heart rate and blood pressure during isometric exercise, six healthy male subjects performed three calf ergometer test with different extracellular volumes of working muscles. In all tests, body positions during exercise were identical (supine with the knee joint flexed to 900). After a pre-exercise period of 25 min, during which calf volumes were manipulated, subjects had to counteract an external force of 180 N for 5 min. During the pre-exercise period three different protocols were applied. Test A: Subjects rested in the exercise position; test B: Body position was the same as in A but calf volume was increased by venous congestion (cuffs inflated to 80 mm Hg); test C: Calf volumes were decreased by a negative hydrostatic pressure (calves about 40 cm above heart level with the subjects supine). To clamp the changed calf volumes in tests B and C, cuffs were inflated to 300 mm Hg 5 min before the onset of exercise. This occlusion was maintained until termination of exercise. Compared to tests A and B, the reduced volume of test C led to significant increases in heart rate and blood pressure during exercise. Oxygen uptake did not exceed resting levels in B and C until cuffs were deflated, indicating that exclusively calf muscles contributed to the neurogenic peripheral drive. It is concluded that changes in extracellular muscle volume have to be taken into account when comparing heart rate and blood pressure during lg- and μg- exercise.

  2. Determination of equine deep digital flexor muscle volume based on distances between anatomical landmarks.

    PubMed

    Hardeman, L C; van der Meij, B R; Lamers, A A H; van der Kolk, J H; Back, W; Wijnberg, I D

    2014-10-01

    In equine medicine the use of Botox® is experimental. Dosages are determined from human treatment-protocols and limited numbers of equine studies. Determination of target-muscle volume can be helpful to extrapolate human dosages. The aim of the study was to calculate a formula enabling the estimation of the deep digital flexor muscle (DDFM) volume based on distances between anatomical landmarks. Nineteen cadaveric limbs were collected and distance A (top of olecranon to Os carpi accessorium) and B (circumference of limb) were measured. Converting mathematical formulas, C was calculated: π × (((0.5B)/π)(2)) × A. DDFM volume was determined by water displacement. Linear Regression Analysis was used to analyse data. The line best fitting the observed points was: Ln(volume[ml]) = -1.89 + 0.98 × Ln(value C[cm(3)]). Correlation was highest when natural logarithm was applied to both variables and was 0.97. The calculated formula enables estimating DDFM volume of a living horse. This estimated volume can be useful to apply human Botox® treatment-protocols.

  3. Functional and molecular expression of volume-regulated chloride channels in canine vascular smooth muscle cells

    PubMed Central

    Yamazaki, Jun; Duan, Dayue; Janiak, Robert; Kuenzli, Karri; Horowitz, Burton; Hume, Joseph R

    1998-01-01

    We examined the possibility of functional and molecular expression of volume-regulated Cl− channels in vascular smooth muscle using the whole-cell patch-clamp technique and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) on cells from canine pulmonary and renal arteries. Decreasing external osmolarity induced cell swelling, which was accompanied by activation of Cl−-dependent outward-rectifying membrane currents with an anion permeability sequence of SCN− > I− > Br− > Cl− > aspartate−. These currents were sensitive to block by DIDS, extracellular ATP and the antioestrogen compound tamoxifen. Experiments were performed to determine whether the molecular form of the volume-regulated chloride channel (ClC-3) is expressed in pulmonary and renal arteries. Quantitative RT-PCR confirmed expression of ClC-3 in both types of smooth muscle. ClC-3 expression was 76.4% of β-actin in renal artery and 48.0% of β-actin in pulmonary artery. We conclude that volume-regulated Cl− channels are expressed in vascular smooth muscle cells and exhibit functional properties similar to those found in other types of cells, presumably contributing to the regulation of cell volume, electrical activity and, possibly, myogenic tone. PMID:9508834

  4. Psoas muscle volume as a predictor of peripheral neurotoxicity induced by primary chemotherapy in ovarian cancers.

    PubMed

    Yoshikawa, Tomoyuki; Takano, Masashi; Miyamoto, Morikazu; Yajima, Isao; Shimizu, Yukihiro; Aizawa, Yusuke; Suguchi, Yuki; Moriiwa, Miki; Aoyama, Tadashi; Soyama, Hiroaki; Goto, Tomoko; Hirata, Junko; Suzuki, Ayako; Sasa, Hidenori; Nagaoka, Isao; Tsuda, Hitoshi; Furuya, Kenichi

    2017-07-19

    Low skeletal muscle mass (sarcopenia) has been reported to have an influence on survival and toxicities of chemotherapy in several solid tumors. The impact of sarcopenia on the treatment of ovarian cancers has not been determined. The present study aimed to evaluate correlation between sarcopenia and toxicities of chemotherapy in ovarian cancers. Medical charts of the ovarian cancer patients that received chemotherapy with paclitaxel and carboplatin at our hospital between 2010 and 2015 were retrospectively reviewed. Muscle areas of bilateral psoas major muscles at the fifth lumbar vertebra were measured using images obtained by computed tomography. The volume of muscle and clinicopathological factors were evaluated for toxicities of chemotherapy. The protocol of the present study was approved by the institutional review board of our institution. A total of 76 patients with ovarian cancers were identified, and enrolled in the present study. Median psoas index (PI, the psoas muscle major cross-sectional area divided by the height squared) was 583 mm(2)/m(2) (range 326-999). The patients with low PI developed peripheral neuropathy more frequently compared with those with high PI (32 vs. 11%; P = 0.047). PI value was not associated with other toxicities such as neutropenia and thrombocytopenia. PI value was associated with grade 2 or higher peripheral neuropathy in univariate analysis (OR = 3.92; 95% CI 1.21-15.32; P = 0.02) and multivariate analysis (OR = 3.93; 95% CI 1.17-15.87; P = 0.03). PI value was significantly associated with peripheral neuropathy induced by combination therapy with paclitaxel and carboplatin in ovarian cancer patients. Although further studies are needed to confirm the results, the volume of skeletal muscle mass could be a potential biomarker to predict toxicities in ovarian cancer patients.

  5. Increases in muscle volume after plantarflexor strength training in children with spastic cerebral palsy.

    PubMed

    McNee, Anne E; Gough, Martin; Morrissey, Matt C; Shortland, Adam P

    2009-06-01

    Children with spastic cerebral palsy (CP) have small, weak muscles. However, change in muscle size due to resistance training in this group is unknown. We investigated the effect of plantarflexor strengthening on muscle volume, gait, and function in 13 ambulant children with spastic CP (seven males, six females; mean age 10 y 11 mo, SD 3 y 0 mo, range 6 y 11 mo-16 y 11 mo; eight with diplegia, five with hemiplegia; Gross Motor Function Classification System level I, six; level II, five; level III, two). Assessments were performed before training, 5 and 10 weeks into training, and at a 3-month follow-up. Medial and lateral gastrocnemius volumes were computed from three-dimensional ultrasound images. The number of unilateral heel raises able to be achieved on each side was assessed. Function was measured using three-dimensional gait analysis, the 'timed up and go' test, the Gillette Functional Assessment Questionnaire, and the Functional Mobility Scale. Training involved heel raises or Thera-Band resistance, 4 times a week for 10 weeks. Medial and lateral gastrocnemius volumes increased by 17 and 14% at week 5 (p=0.03, p=0.028). This increase was maintained at week 10 and follow-up (medial gastrocnemius p=0.001, p<0.001; lateral gastrocnemius p=0.006, p=0.007). Heel raises (mean number) increased by week 5 (p=0.002). This was maintained at week 10 and follow-up (p<0.001; p<0.001). No significant change in measured function was observed. Muscle volume increased in response to training in children with spastic CP. The role of progressive strength training in maintaining long-term function is discussed.

  6. The Development of a Flexible Measuring System for Muscle Volume Using Ultrasonography

    NASA Astrophysics Data System (ADS)

    Fukumoto, Kiyotaka; Fukuda, Osamu; Tsubai, Masayoshi; Muraki, Satoshi

    Quantification of muscle volume can be used as a means for the estimation of muscle strength. Its measuring process does not need the subject's muscular contractions so it is completely safe and particularly suited for elderly people. Therefore, we have developed a flexible measuring system for muscle volume using ultrasonography. In this system, an ultrasound probe is installed on a link mechanism which continuously scans fragmental images along the human body surface. These images are then measured and composed into a wide area cross-sectional image based on the spatial compounding method. The flexibility of the link mechanism enables the operator to measure the images under any body postures and body site. The spatial compounding method significantly reduces speckle and artifact noises from the composed cross-sectional image so that the operator can observe the individual muscles, such as Rectus femoris, Vastus intermedius, and so on, in detail. We conducted the experiments in order to examine the advantages of this system we have developed. The experimental results showed a high accuracy of the measuring position which was calculated using the link mechanism and presented the noise reduction effect based on the spatial compounding method. Finally, we confirmed high correlations between the MRI images and the ones of the developed system to verify the validity of the system.

  7. Volume regulation in mammalian skeletal muscle: the role of sodium–potassium–chloride cotransporters during exposure to hypertonic solutions

    PubMed Central

    Lindinger, Michael I; Leung, Matthew; Trajcevski, Karin E; Hawke, Thomas J

    2011-01-01

    Abstract Controversy exists as to whether mammalian skeletal muscle is capable of volume regulation in response to changes in extracellular osmolarity despite evidence that muscle fibres have the required ion transport mechanisms to transport solute and water in situ. We addressed this issue by studying the ability of skeletal muscle to regulate volume during periods of induced hyperosmotic stress using single, mouse extensor digitorum longus (EDL) muscle fibres and intact muscle (soleus and EDL). Fibres and intact muscles were loaded with the fluorophore, calcein, and the change in muscle fluorescence and width (single fibres only) used as a metric of volume change. We hypothesized that skeletal muscle exposed to increased extracellular osmolarity would elicit initial cellular shrinkage followed by a regulatory volume increase (RVI) with the RVI dependent on the sodium–potassium–chloride cotransporter (NKCC). We found that single fibres exposed to a 35% increase in extracellular osmolarity demonstrated a rapid, initial 27–32% decrease in cell volume followed by a RVI which took 10–20 min and returned cell volume to 90–110% of pre-stimulus values. Within intact muscle, exposure to increased extracellular osmolarity of varying degrees also induced a rapid, initial shrinkage followed by a gradual RVI, with a greater rate of initial cell shrinkage and a longer time for RVI to occur with increasing extracellular tonicities. Furthermore, RVI was significantly faster in slow-twitch soleus than fast-twitch EDL. Pre-treatment of muscle with bumetanide (NKCC inhibitor) or ouabain (Na+,K+-ATPase inhibitor), increased the initial volume loss and impaired the RVI response to increased extracellular osmolarity indicating that the NKCC is a primary contributor to volume regulation in skeletal muscle. It is concluded that mouse skeletal muscle initially loses volume then exhibits a RVI when exposed to increases in extracellular osmolarity. The rate of RVI is dependent

  8. Volume regulation in mammalian skeletal muscle: the role of sodium-potassium-chloride cotransporters during exposure to hypertonic solutions.

    PubMed

    Lindinger, Michael I; Leung, Matthew; Trajcevski, Karin E; Hawke, Thomas J

    2011-06-01

    Controversy exists as to whether mammalian skeletal muscle is capable of volume regulation in response to changes in extracellular osmolarity despite evidence that muscle fibres have the required ion transport mechanisms to transport solute and water in situ. We addressed this issue by studying the ability of skeletal muscle to regulate volume during periods of induced hyperosmotic stress using single, mouse extensor digitorum longus (EDL) muscle fibres and intact muscle (soleus and EDL). Fibres and intact muscles were loaded with the fluorophore, calcein, and the change in muscle fluorescence and width (single fibres only) used as a metric of volume change. We hypothesized that skeletal muscle exposed to increased extracellular osmolarity would elicit initial cellular shrinkage followed by a regulatory volume increase (RVI) with the RVI dependent on the sodium–potassium–chloride cotransporter (NKCC). We found that single fibres exposed to a 35% increase in extracellular osmolarity demonstrated a rapid, initial 27–32% decrease in cell volume followed by a RVI which took 10-20 min and returned cell volume to 90–110% of pre-stimulus values. Within intact muscle, exposure to increased extracellular osmolarity of varying degrees also induced a rapid, initial shrinkage followed by a gradual RVI, with a greater rate of initial cell shrinkage and a longer time for RVI to occur with increasing extracellular tonicities. Furthermore, RVI was significantly faster in slow-twitch soleus than fast-twitch EDL. Pre-treatment of muscle with bumetanide (NKCC inhibitor) or ouabain (Na+,K+-ATPase inhibitor), increased the initial volume loss and impaired the RVI response to increased extracellular osmolarity indicating that the NKCC is a primary contributor to volume regulation in skeletal muscle. It is concluded that mouse skeletal muscle initially loses volume then exhibits a RVI when exposed to increases in extracellular osmolarity. The rate of RVI is dependent on the

  9. Editorial Commentary: Single-Image Slice Magnetic Resonance Imaging Assessments Do Not Predict 3-Dimensional Muscle Volume.

    PubMed

    Brand, Jefferson C

    2016-01-01

    No single-image magnetic resonance imaging (MRI) assessment-Goutallier classification, Fuchs classification, or cross-sectional area-is predictive of whole-muscle volume or fatty atrophy of the supraspinatus or infraspinatus. Rather, 3-dimensional MRI measurement of whole-muscle volume and fat-free muscle volume is required and is associated with shoulder strength, which is clinically relevant. Three-dimensional MRI may represent a new gold standard for assessment of the rotator cuff musculature using imaging and may help to predict the feasibility of repair of a rotator cuff tear as well as the postoperative outcome. Unfortunately, 3-dimensional MRI assessment of muscle volume is labor intensive and is not widely available for clinical use. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  10. Systematic Test of Neurotoxin Dose and Volume on Muscle Function in a Rat Model

    PubMed Central

    Hulst, Jonah B.; Minamoto, Viviane B.; Lim, Michael B.; Bremner, Shannon N.; Ward, Samuel R.; Lieber, Richard L.

    2015-01-01

    Introduction Botulinum toxin serotype A (BT-A) is used for a variety of motor and sensory disorders related to abnormal muscle activity. Methods We developed a high-resolution rodent model to allow precise determination of the effect of BT-A dose (measured in units) and injectate volume (measured in μL) on the efficacy of the injection and systemic side effects. Dorsiflexion is the best indicator of injected and contralateral muscle function. Results One month after injection, dorsiflexion torque of BT-A-injected limbs was decreased significantly in all experimental groups compared with saline controls (P<0.05). Torque was also compared among the BT-A groups, which demonstrated a significant effect of dose (P<0.001), but no effect of volume (P>0.2) and no dose x volume interaction (P>0.3). Similar results were observed for other parameters measured. Discussion These data demonstrate that injection dose and not volume or concentration is the primary determinant of neurotoxin efficacy in a rodent model. PMID:23929710

  11. Study on contraction and relaxation of experimentally denervated and immobilized muscles: Comparison with dystrophic muscles

    NASA Technical Reports Server (NTRS)

    Takamori, M.; Tsujihata, M.; Mori, M.; Hazama, R.; Ide, Y.

    1980-01-01

    The contraction-relaxation mechanism of experimentally denervated and immobilized muscles of the rabbit is examined. Results are compared with those of human dystrophic muscles, in order to elucidate the role and extent of the neurotrophic factor, and the role played by the intrinsic activity of muscle in connection with pathogenesis and pathophysiology of this disease.

  12. Effect of blood volume in resting muscle on heart rate upward drift during moderately prolonged exercise.

    PubMed

    Kimura, Takehide; Matsuura, Ryouta; Arimitsu, Takuma; Yunoki, Takahiro; Yano, Tokuo

    2010-01-01

    The aim of this study was to determine whether the increase in blood volume in resting muscle during moderately prolonged exercise is related to heart rate (HR) upward drift. Eight healthy men completed both arm-cranking moderately prolonged exercise (APE) and leg-pedaling moderately prolonged exercise (LPE) for 30 min. Exercise intensity was 120 bpm of HR that was determined by ramp incremental exercise. During both APE and LPE, HR significantly increased from 3 to 30 min (from 108±9.3 to 119±12 bpm and from 112±8.9 to 122±11 bpm, respectively). However, there was no significant difference between HR in APE and that in LPE. Oxygen uptake was maintained throughout the two exercises. Skin blood flow, deep temperature, and total Hb (blood volume) in resting muscle continuously increased for 30 min of exercise during both APE and LPE. During both APE and LPE, there was a significant positive correlation between total Hb and deep temperature in all subjects. Moreover, there was a significant positive correlation between HR and total Hb (in seven out of eight subjects) during LPE. However, during APE, there was no positive correlation between HR and total Hb (r=0.391). These findings suggest that an increase of blood pooling in resting muscle could be proposed as one of the mechanisms underlying HR upward drift during moderately prolonged exercise.

  13. Lateral pterygoid muscle volume and migraine in patients with temporomandibular disorders.

    PubMed

    Lopes, Sérgio Lúcio Pereira de Castro; Costa, André Luiz Ferreira; Gamba, Thiago de Oliveira; Flores, Isadora Luana; Cruz, Adriana Dibo; Min, Li Li

    2015-03-01

    Lateral pterygoid muscle (LPM) plays an important role in jaw movement and has been implicated in Temporomandibular disorders (TMDs). Migraine has been described as a common symptom in patients with TMDs and may be related to muscle hyperactivity. This study aimed to compare LPM volume in individuals with and without migraine, using segmentation of the LPM in magnetic resonance (MR) imaging of the TMJ. Twenty patients with migraine and 20 volunteers without migraine underwent a clinical examination of the TMJ, according to the Research Diagnostic Criteria for TMDs. MR imaging was performed and the LPM was segmented using the ITK-SNAP 1.4.1 software, which calculates the volume of each segmented structure in voxels per cubic millimeter. The chi-squared test and the Fisher's exact test were used to relate the TMD variables obtained from the MR images and clinical examinations to the presence of migraine. Logistic binary regression was used to determine the importance of each factor for predicting the presence of a migraine headache. Patients with TMDs and migraine tended to have hypertrophy of the LPM (58.7%). In addition, abnormal mandibular movements (61.2%) and disc displacement (70.0%) were found to be the most common signs in patients with TMDs and migraine. In patients with TMDs and simultaneous migraine, the LPM tends to be hypertrophic. LPM segmentation on MR imaging may be an alternative method to study this muscle in such patients because the hypertrophic LPM is not always palpable.

  14. Quantitative force comparison of polyacrylonitrile fibers with skeletal muscle

    NASA Astrophysics Data System (ADS)

    Gonzalez, Roger V.; Lee, Christopher Y.

    1998-07-01

    The possibility of using certain polymer gels as artificial skeletal muscle was investigated due to its ability to shorten or contract when saturated in acidic or basic solutions, respectively. Polyacrylonitrile (PAN) fiber is such an example of a polymer gel. Mechanical performance characteristics of PAN fibers were studied and compared to voluntary muscle mechanical properties. The experimental methods used to determine the mechanical properties of the PAN fibers were modeled after A. V. Hill's classic experiments of the force-length and force-velocity properties of voluntary muscle. In addition, the force-molarity, length-molarity, and force-time characteristics were measured for the PAN fibers. These characteristics were quantitatively and qualitatively compared to voluntary muscle properties when relevant and used to determine the feasibility of implementing PAN fibers as artificial skeletal muscle in modeling movement across the human elbow joint. The results indicated qualitative similarities with the mechanical characteristics of voluntary muscle, especially force-velocity property. The force capabilities of the PAN fibers were at the lower end of voluntary muscle force generation. (i.e. 20 - 200 N/cm2) Activation- contraction time was also substantially larger than skeletal muscle. Based on these data, it was concluded that using PAN fibers as artificial muscles in modeling the human elbow joint is feasible only under certain conditions. Additional characterization studies are needed to determine if individual PAN fibers can generate higher forces using a different experimental protocol or a different architectural arrangement of the fibers.

  15. Effect of isosmotic removal of extracellular Na+ on cell volume and membrane potential in muscle cells.

    PubMed

    Peña-Rasgado, C; Summers, J C; McGruder, K D; DeSantiago, J; Rasgado-Flores, H

    1994-09-01

    Isosmotic removal of extracellular Na+ (Nao) is a frequently performed manipulation. With the use of isolated voltage-clamped barnacle muscle cells, the effect of this manipulation on isosmotic cell volume was studied. Replacement of Nao by tris(hydroxymethyl)aminomethane produced membrane depolarization (approximately 20 mV) and cell volume loss (approximately 14%). The membrane depolarization was verapamil insensitive but depended on extracellular Ca2+ (Cao) and was probably due to activation of intracellular Ca2+ (Cai)-dependent nonselective cation channels. The cell volume loss did not require membrane depolarization but depended on Cao. This was probably due to an increase in Cai, mediated by activation of Ca2+ influx via Na+/Ca2+ exchange. Nao replacement by Li+ also promoted membrane depolarization (approximately 20 mV) and cell volume loss (20%). Both effects were reduced (approximately 73%) but were not abolished by Cao removal. Under this condition, the remaining membrane depolarization was probably due to a higher membrane permeability of Li+ over Na+. The remaining cell volume loss was due to membrane depolarization, which probably induced Ca2+ release from intracellular stores.

  16. Comparison of Muscle Force after Immediate and Delayed Reinnervation Using Nerve-Muscle-Endplate Band Grafting

    PubMed Central

    Sobotka, Stanislaw; Mu, Liancai

    2012-01-01

    Background Because of poor functional outcomes of currently used reinnervation methods, we developed novel treatment strategy for the restoration of paralyzed muscles - the nerve-muscle-endplate band grafting (NMEG) technique. The graft was obtained from the sternohyoid (SH) muscle (donor) and implanted into the ipsilateral paralyzed sternomastoid (SM) muscle (recipient). Methods Rats were subjected to immediate or delayed (1 or 3 months) reinnervation of the experimentally paralyzed SM muscles using the NMEG technique or the conventionally used nerve end-to-end anastomosis (EEA). The SM muscle at the opposite side served as a normal control. Results NMEG produced better recovery of muscle force as compared to EEA. A larger force produced by NMEG was most evident for small stimulation currents. Conclusions The NMEG technique holds great potential for successful muscle reinnervation. We hypothesize that even better muscle reinnervation and functional recovery could be achieved with further improvement of the environment that favors axon-endplate connections and accelerates axonal growth and sprouting. PMID:22480827

  17. Leg muscle volume during 30-day 6-degree head-down bed rest with isotonic and isokinetic exercise training

    NASA Technical Reports Server (NTRS)

    Greenleaf, J. E.; Lee, P. L.; Ellis, S.; Selzer, R. H.; Ortendahl, D. A.

    1994-01-01

    Magnetic resonance imaging (MRI) was used to compare the effect of two modes of lower-extremity exercise training on the mass (volume) of posterior leg group (PLG) muscles (soleus, flexor hallucis longus, tibialis posterior, lateral and medial gastrocnemius, and flexor digitorum longus) on 19 men (ages 32-42 years) subjected to intense dynamic-isotonic (ITE, cycle ergometer, number of subjects (N) = 7), isokinetic (IKE, torque egrometer, N = 7), and no exercise (NOE, N = 5) training for 60 min/day during head-down bed rest (HDBR). Total volume of the PLG muscles decreased (p less than 0.05) similarly: ITE = 4.3 +/- SE 1.6%, IKE = 7.7 +/- 1.6%, and NOE = 6.3 +/- 0.8%; combined volume (N = 19) loss was 6.1 +/- 0.9%. Ranges of volume changes were 2.6% to -9.0% (ITE), -2.1% to -14.9% (IKE), and -3.4% to -8/1% (NOE). Correlation coefficients (r) of muscle volume versus thickness measured with ultrasonography were: ITE r + 0.79 (p less than 0.05), IKE r = 0.27 (not significant (NS)), and NOE r = 0.63 (NS). Leg-muscle volume and thickness were highly correlated (r = 0.79) when plasma volume was maintained during HDBR with ITE. Thus, neither intensive lower extremity ITE nor IKE training influence the normal non-exercised posterior leg muscle atrophy during HDBR. The relationship of muscle volume and thickness may depend on the mode of exercise training associated with the maintenance of plasma volume.

  18. Changes in perceived recovery status scale following high-volume muscle damaging resistance exercise.

    PubMed

    Sikorski, Eric M; Wilson, Jacob M; Lowery, Ryan P; Joy, Jordan M; Laurent, C Matthew; Wilson, Stephanie M-C; Hesson, Domini; Naimo, Marshall A; Averbuch, Brian; Gilchrist, Phil

    2013-08-01

    Currently no research has investigated the relationship between muscle damage, hormonal status, and perceived recovery scale (PRS). Therefore, the purpose of this study was to determine the effects of a high-volume training session on PRS and to determine the relationship between levels of testosterone, cortisol, and creatine kinase (CK) and PRS. Thirty-five trained subjects (21.3 ± 1.9 years) were recruited. All subjects participated in a high-volume resistance training session consisting of 3 sets of full squats, bench press, deadlifts, pullups, dips, bent over rows, shoulder press, and barbell curls and extensions. Pre-PRS and post-PRS measurements (0-10), soreness, CK, cortisol, and testosterone were measured before and 48 hours after training. Perceived recovery scale declined from 8.6 ± 2.3 to 4.2 ± 1.85 (p < 0.05). Leg, chest, and arm soreness increased from pre- to postexercise. Creatine kinase significantly increased from pre- to postworkout (189.4 ± 100.2 to 512 ± 222.7 U/L). Cortisol, testosterone, and free testosterone did not change. There was an inverse relationship between CK and PRS (r = 0.58, p < 0.05). When muscle damage was low before training, cortisol and free and total testosterone were not correlated to PRS. However, when damage peaked at 48 hours postexercise, free, but not total, testosterone showed a low direct relationship with PRS (r = 0.2, p < 0.05). High-volume resistance exercise lowers PRS scores. These changes are partly explained by a rise in serum indices of muscle damage. Moreover, free testosterone seems to have a positive relationship with PRS.

  19. Effects of Volume Training on Strength and Endurance of Back Muscles: A Randomized Controlled Trial.

    PubMed

    Shigaki, Leonardo; Araújo, Cynthia Gobbi Alves; Calderon, Mariane Guizeline; Costa, Thais Karoline Cezar; Aguiar, Andreo Fernando; Costa, Leonardo Oliveira Pena; da Silva, Rubens A

    2017-05-17

    Strength/resistance training volume has historically been supported in the American College of Sports Medicine recommendations. However, for the back muscles, exercise prescription related to the number of sets, such as single vs. multiple, is not well established in the literature. The purpose of this study was to compare the effects of two training volumes on strength and endurance of back extensor muscles in untrained young participants, with regard to a repeated measures design. Randomized controlled trial. Laboratory of functional evaluation and human motor performance. Forty-four untrained young participants (mean age= 21 yrs) were randomized into three groups: single set (SSG, n= 14), multiple sets (MSG, n= 15), and untrained control (CG, n= 15). The SSG and MSG underwent a 10-wk progressive resistance training program (2 days·week(-1)) using a 45° Roman chair. Back maximal strength (dynamometer) and isometric and dynamic endurance (time-limit, trunk extension-flexion cycles, and electromyography muscle fatigue estimates). The results showed differences between the MSG and control group for isometric endurance time (mean 19.8 seconds, 95% CI 44.1 to 4.8), but without time intervention significance. Significant improvement after training (P <0.05) was found predominantly during dynamic endurance (number of repetitions) for both the MSG (+61%) and SSG (+26%) compared to pre-intervention, while the control group reported no benefit. There was no significant (P > 0.05) difference in either strength or electromyography estimates after training. Both multiple and single volume training were efficient in promoting better back endurance during dynamic performance based on mechanical variables (time and number of repetitions).

  20. Calcium and magnesium contents and volume of the terminal cisternae in caffeine-treated skeletal muscle

    PubMed Central

    1984-01-01

    (a) The effects of caffeine on the composition and volume of the terminal cisternae (TC) of the sarcoplasmic reticulum (SR) in frog skeletal muscle were determined with rapid freezing, electron microscopy, and electron probe analysis. (b) Caffeine (5 mM) released approximately 65% of the Ca content of the TC in 1 min and 84% after 3 min. The release of Ca from the TC was associated with a highly significant increase in its Mg content. This increase in Mg was not reduced by valinomycin. There was also a small increase in the K content of the TC at 1 min, although not after 3 min of caffeine contracture. (c) On the basis of the increase in Mg content during caffeine contracture and during tetanus (Somlyo, A. V., H. Gonzalez- Serratos, H. Shuman, G. McClellan, and A. P. Somlyo, 1981, J. Cell Biol., 90:577-594), we suggest that both mechanisms of Ca release are associated with an increase in the Ca and Mg permeability of the SR membranes, the two ions possibly moving through a common channel. (d) There was a significant increase in the P content of the TC during caffeine contracture, while in tetanized muscle (see reference above) there was no increase in the P content of the TC. (e) Mitochondrial Ca content was significantly increased (at 1 and at 3 min) during caffeine contracture. Valinomycin (5 microM) blocked this mitochondrial Ca uptake. (f) The sustained Ca release caused by caffeine in situ contrasts with the transient Ca release observed in studies of fragmented SR preparations, and could be explained by mediation of the caffeine-induced Ca release by a second messenger produced more readily in intact muscle than in isolated SR. (g) The TC were not swollen in rapidly frozen, caffeine-treated muscles, in contrast to the swelling of the TC observed in conventionally fixed, caffeine-treated preparation, the latter finding being in agreement with previous studies. (h) The fractional volume of the TC in rapidly frozen control (resting) frog semitendinosus muscles

  1. Comparison between muscle activation measured by electromyography and muscle thickness measured using ultrasonography for effective muscle assessment.

    PubMed

    Kim, Chang-Yong; Choi, Jong-Duk; Kim, Suhn-Yeop; Oh, Duck-Won; Kim, Jin-Kyung; Park, Ji-Whan

    2014-10-01

    In this study, we aimed to compare the intrarater reliability and validity of muscle thickness measured using ultrasonography (US) and muscle activity via electromyography (EMG) during manual muscle testing (MMT) of the external oblique (EO) and lumbar multifidus (MF) muscles. The study subjects were 30 healthy individuals who underwent MMT at different grades. EMG was used to measure the muscle activity in terms of ratio to maximum voluntary contraction (MVC) and root mean square (RMS) metrics. US was used to measure the raw muscle thickness, the ratio of muscle thickness at MVC, and the ratio of muscle thickness at rest. One examiner performed measurements on each subject in 3 trials. The intrarater reliabilities of the % MVC RMS and raw RMS metrics for EMG and the % MVC thickness metrics for US were excellent (ICC=0.81-0.98). There was a significant difference between all the grades measured using the % MVC thickness metric (p<0.01). Further, this % MVC thickness metric of US showed a significantly higher correlation with the EMG measurement methods than with the others (r=0.51-0.61). Our findings suggest that the % MVC thickness determined by US was the most sensitive of all methods for assessing the MMT grade.

  2. Ultrasonographic analysis of dorsal neck muscles thickness changes induced by isometric contraction of shoulder muscles: A comparison between patients with chronic neck pain and healthy controls.

    PubMed

    Karimi, Noureddin; Rezasoltani, Asghar; Rahnama, Leila; Noori-Kochi, Farhang; Jaberzadeh, Shapour

    2016-04-01

    Altered pattern of muscle activity is commonly seen with chronic neck pain (CNP). However, limited investigations have been done on dorsal neck muscles' activity pattern while performing upper limb tasks in patients with CNP. To investigate dorsal neck muscles' thickness changes during isometric contraction of shoulder muscles. Case-control study. This study investigated dorsal neck muscles' thickness changes during isometric contraction of shoulder muscles in 20 healthy participants (mean age 27 ± 4.37) and 17 patients with CNP (mean age 29 ± 5.50). Effects of isometric force of shoulder muscles on dorsal neck muscles' thickness changes were also evaluated. Significant muscle × group interaction was observed for the dorsal neck muscles thickness changes (p = 0.008) indicating different pattern of muscle activity in terms of changes in muscle thickness of two groups. Significant main effects of direction was observed (P = 0.003), with the abduction had the greatest impact on changing the dorsal neck muscles thickness. patients with CNP showed altered pattern of muscle thickness changes in comparison to healthy participants. Isometric abduction of shoulder muscles induced the greatest changes of dorsal neck muscles thickness among other force directions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. [A comparison between prostatic volume measured during suprapubic ultrasonography (TAUS) and volume of the enucleated gland after open prostatectomy].

    PubMed

    Szewczyk, Wojciech; Prajsner, Andrzej; Kozina, Janusz; Login, Tomasz; Kaczorowski, Marek

    2004-01-01

    General practitioner very often uses transabdominal ultrasonograpy (TAUS) in order to measure prostatic volume. Using this method it is rather impossible to distinguish between tissue of benign prostatic hyperplasia (BPH) and prostatic tissue which forms so called surgical capsule of BPH. The aim of this study was a comparison of prostatic volume measured during suprapubic (transabdominal) ultrasonography and volume of the enucleated gland after open prostatectomy. Regarding the results authors created a nomogram based on TAUS measurement of the prostate which helps to predict the volume of BPH. They also stated that surgical capsule of the BPH makes about 1/3 of the whole volume of the prostate measured by TAUS.

  4. Trunk Muscle Activities During Abdominal Bracing: Comparison Among Muscles and Exercises

    PubMed Central

    Maeo, Sumiaki; Takahashi, Takumi; Takai, Yohei; Kanehisa, Hiroaki

    2013-01-01

    Abdominal bracing is often adopted in fitness and sports conditioning programs. However, there is little information on how muscular activities during the task differ among the muscle groups located in the trunk and from those during other trunk exercises. The present study aimed to quantify muscular activity levels during abdominal bracing with respect to muscle- and exercise-related differences. Ten healthy young adult men performed five static (abdominal bracing, abdominal hollowing, prone, side, and supine plank) and five dynamic (V- sits, curl-ups, sit-ups, and back extensions on the floor and on a bench) exercises. Surface electromyogram (EMG) activities of the rectus abdominis (RA), external oblique (EO), internal oblique (IO), and erector spinae (ES) muscles were recorded in each of the exercises. The EMG data were normalized to those obtained during maximal voluntary contraction of each muscle (% EMGmax). The % EMGmax value during abdominal bracing was significantly higher in IO (60%) than in the other muscles (RA: 18%, EO: 27%, ES: 19%). The % EMGmax values for RA, EO, and ES were significantly lower in the abdominal bracing than in some of the other exercises such as V-sits and sit-ups for RA and EO and back extensions for ES muscle. However, the % EMGmax value for IO during the abdominal bracing was significantly higher than those in most of the other exercises including dynamic ones such as curl-ups and sit-ups. These results suggest that abdominal bracing is one of the most effective techniques for inducing a higher activation in deep abdominal muscles, such as IO muscle, even compared to dynamic exercises involving trunk flexion/extension movements. Key Points Trunk muscle activities during abdominal bracing was examined with regard to muscle- and exercise-related differences. Abdominal bracing preferentially activates internal oblique muscles even compared to dynamic exercises involving trunk flexion/extension movements. Abdominal bracing should be

  5. Neck muscle cross-sectional area, brain volume and cognition in healthy older men: a cohort study.

    PubMed

    Kilgour, Alixe H M; Ferguson, Karen J; Gray, Calum D; Deary, Ian J; Wardlaw, Joanna M; MacLullich, Alasdair M J; Starr, John M

    2013-02-28

    Two important consequences of the normal ageing process are sarcopenia (the age-related loss of muscle mass and function) and age-related cognitive decline. Existing data support positive relationships between muscle function, cognition and brain structure. However, studies investigating these relationships at older ages are lacking and rarely include a measure of muscle size. Here we test whether neck muscle size is positively associated with cognition and brain structure in older men. We studied 51 healthy older men with mean age 73.8 (sd 1.5) years. Neck muscle cross-sectional area (CSA) was measured from T1-weighted MR-brain scans using a validated technique. We measured multiple cognitive domains including verbal and visuospatial memory, executive functioning and estimated prior cognitive ability. Whole brain, ventricular, hippocampal and cerebellar volumes were measured with MRI. General linear models (ANCOVA) were performed. Larger neck muscle CSA was associated with less whole brain atrophy (t = 2.86, p = 0.01, partial eta squared 17%). Neck muscle CSA was not associated with other neuroimaging variables or current cognitive ability. Smaller neck muscle CSA was unexpectedly associated with higher prior cognition (t = -2.12, p < 0.05, partial eta squared 10%). In healthy older men, preservation of whole brain volume (i.e. less atrophy) is associated with larger muscle size. Longitudinal ageing studies are now required to investigate these relationships further.

  6. Comparison of isokinetic muscle strength and muscle power by types of warm-up.

    PubMed

    Sim, Young-Je; Byun, Yong-Hyun; Yoo, Jaehyun

    2015-05-01

    [Purpose] The purpose of this study was to clarify the influence of static stretching at warm-up on the isokinetic muscle torque (at 60°/sec) and muscle power (at 180°/sec) of the flexor muscle and extensor muscle of the knee joint. [Subjects and Methods] The subjects of this study were 10 healthy students with no medically specific findings. The warm-up group and warm-up with stretching group performed their respective warm-up prior to the isokinetic muscle torque evaluation of the knee joint. One-way ANOVA was performed by randomized block design for each variable. [Results] The results were as follows: First, the flexor peak torque and extensor peak torque of the knee joint tended to decrease at 60°/sec in the warm-up with stretching group compared with the control group and warm-up group, but without statistical significance. Second, extensor power at 180°/sec was also not statistically significant. However, it was found that flexor power increased significantly in the warm-up with stretching group at 180°/sec compared with the control group and warm-up group in which stretching was not performed. [Conclusion] Therefore, it is considered that in healthy adults, warm-up including two sets of stretching for 20 seconds per muscle group does not decrease muscle strength and muscle power.

  7. Comparison of isokinetic muscle strength and muscle power by types of warm-up

    PubMed Central

    Sim, Young-Je; Byun, Yong-Hyun; Yoo, Jaehyun

    2015-01-01

    [Purpose] The purpose of this study was to clarify the influence of static stretching at warm-up on the isokinetic muscle torque (at 60°/sec) and muscle power (at 180°/sec) of the flexor muscle and extensor muscle of the knee joint. [Subjects and Methods] The subjects of this study were 10 healthy students with no medically specific findings. The warm-up group and warm-up with stretching group performed their respective warm-up prior to the isokinetic muscle torque evaluation of the knee joint. One-way ANOVA was performed by randomized block design for each variable. [Results] The results were as follows: First, the flexor peak torque and extensor peak torque of the knee joint tended to decrease at 60°/sec in the warm-up with stretching group compared with the control group and warm-up group, but without statistical significance. Second, extensor power at 180°/sec was also not statistically significant. However, it was found that flexor power increased significantly in the warm-up with stretching group at 180°/sec compared with the control group and warm-up group in which stretching was not performed. [Conclusion] Therefore, it is considered that in healthy adults, warm-up including two sets of stretching for 20 seconds per muscle group does not decrease muscle strength and muscle power. PMID:26157247

  8. Effect of pattern and severity of respiratory muscle weakness on carbon monoxide gas transfer and lung volumes.

    PubMed

    Hart, N; Cramer, D; Ward, S P; Nickol, A H; Moxham, J; Polkey, M I; Pride, N B

    2002-10-01

    In clinical practice, an elevated carbon monoxide (CO) transfer coefficient (KCO) and restrictive ventilatory defect are taken as features of respiratory muscle weakness (RMW). However, the authors hypothesised that both pattern and severity of RMW effect gas transfer and lung volumes. Measurements of CO transfer and lung volumes were performed in patients with isolated diaphragm weakness (n=10), inspiratory muscle weakness (n=12), combined inspiratory and expiratory muscle weakness (n=5) and healthy controls (n=6). Patients with diaphragm weakness and inspiratory muscle weakness had reduced total lung capacity (TLC) (83.6% predicted and 68.9% pred, respectively), functional residual capacity (FRC) (83.9% pred and 83.6% pred) and transfer factor of the lung for CO (TL,CO) (86.2% pred and 66.2% pred) with increased KCO (114.1% pred and 130.2% pred). Patients with combined inspiratory and expiratory muscle weakness had reduced TLC (80.9% pred) but increased FRC (109.9% pred) and RV (157.4% pred) with decreased TL,CO (58.0% pred) and KCO (85.5% pred). In patients with diaphragm weakness, the increase in carbon monoxide transfer coefficient was similar to that of normal subjects when alveolar volume was reduced. However, the increase in carbon monoxide transfer coefficient in inspiratory muscle weakness was often less than expected, while in combined inspiratory and expiratory muscle weakness, the carbon monoxide transfer coefficient was normal/reduced despite further reductions in alveolar volume, which may indicate subtle abnormalities of the lung parenchyma or pulmonary vasculature. Thus, this study demonstrates the limitations of using carbon monoxide transfer coefficient in the diagnosis of respiratory muscle weakness, particularly if no account is taken of the alveolar volume at which the carbon monoxide transfer coefficient is made.

  9. Responses of glutamine transport in cultured rat skeletal muscle to osmotically induced changes in cell volume.

    PubMed Central

    Low, S Y; Taylor, P M; Rennie, M J

    1996-01-01

    1. In order to investigate the relationship between cellular hydration state and the rate of glutamine transport, tracer glutamine uptake into primary rat myotubes was studied at external osmolalities of 170, 320 or 430 mosmol kg-1. 2. Incubation of myotubes with glutamine (2 mM; 30 min) at 320 mosmol kg-1 increased cell volume and glutamine transport (by 35 and 36%, respectively); insulin (66 nM; 30 min) also increased cell volume and glutamine transport (by 22 and 40%, respectively) and the effects of insulin and glutamine combined were additive. The increase in glutamine uptake following glutamine pre-incubation represented an increase in Vmax of Na(+)-dependent glutamine transport. 3. There was an inverse relationship between myotube glutamine transport and external osmolality after 30 min exposure. 4. During hyposmotic (170 mosmol kg-1) exposure there were large, rapid increases of cell volume and glutamine transport; the latter increased transiently (during the cell swelling phase) by a maximum of approximately 80% at 2 min, (due to an increased Vmax for Na(+)-dependent glutamine transport) then decayed to a new elevated steady state after 30 min exposure. 5. During hyperosmotic (430 mosmol kg-1) exposure there were rapid decreases in glutamine transport and myotube cell volume (both by approximately 30%) to values which were maintained for at least 15 min. 6. The volume-sensitive glutamine transport process features characteristics of the insulin-sensitive system Nm transporter. 7. Modulation of Na(+)-dependent glutamine transport by insulin and cell volume changes may contribute towards regulation of muscle metabolism. PMID:8734997

  10. Three-dimensional reconstruction of active muscle cell segment volume from two-dimensional optical sections

    NASA Astrophysics Data System (ADS)

    Lake, David S.; Griffiths, P. J.; Cecchi, G.; Taylor, Stuart R.

    1999-06-01

    An ultramicroscope coupled to a square-aspect-ratio sensor was used to image the dynamic geometry of live muscle cells. Skeletal muscle cells, dissected from frogs, were suspended in the optical axis and illuminated from one side by a focused slit of white light. The sensor detected light scattered at 90 degrees to the incident beam. Serial cross-sections were acquired as a motorized stage moved the cell through the slit of light. The axial force at right angles to the cross- sections was recorded simultaneously. Cross-sections were aligned by a least-squares fit of their centroids to a straight line, to correct for misalignments between the axes of the microscope, the stage, and the sensor. Three- dimensional volumes were reconstructed from each series and viewed from all directions to locate regions that remained at matching axial positions. The angle of the principal axis and the cross-sectional area were calculated and associated with force recorded concurrently. The cells adjusted their profile and volume to remain stable against turning as contractile force rose and fell, as predicted by the law of conservation of angular momentum.

  11. Comparative assessment of right ventricular performance from the pressure-volume relationship in double-muscled and conventional calves.

    PubMed Central

    Amory, H; McEntee, K; Linden, A S; Desmecht, D J; Beduin, J M; D'Orio, V; Lekeux, P M

    1995-01-01

    Forty-one and 55 records of right-sided and systemic arterial pressures, cardiac output, and end-diastolic and end-systolic right ventricular volumes were collected from a group of 6 conventional and 6 double-muscled calves, respectively. In each group, the mean right ventricular pressure-volume loop was constructed. Global cardiac performance was significantly lower in the double-muscled than in the conventional calves. The right ventricular end-diastolic and end-systolic volumes, as well as the diastolic portion of the mean pressure-volume loop, were similar in the 2 groups. Those results suggest that the reduced cardiac performance of double-muscled calves is not due to a lowered ventricular preload and that diastolic properties of their myocardium are similar to those of conventional calves. When expressed on a body weight basis, however, the right ventricular end-diastolic and end-systolic volumes were lower in the double-muscled than in conventional calves. When expressed as a function of probable metabolic demand, therefore, the volumetric capacity of the cardiac pump appears to be reduced in double-muscled calves. The significantly lower right ventricular ejection fraction, maximal rate of ventricular pressure rise and right ventricular peak-systolic pressure to end-systolic volume ratio measured in double-muscled as compared with conventional calves suggest that reduced myocardial contractility may also be partly responsible for the significantly lower stroke index of the former calves. The cardiac pump of double-muscled cattle thus seems to be less effective than that of conventional cattle because of reduced volumetric capacity and lowered strength of contraction. PMID:7648526

  12. Validity of estimating muscle and fat volume from a single MRI section in older adults with sarcopenia and sarcopenic obesity.

    PubMed

    Yang, Y X; Chong, M S; Lim, W S; Tay, L; Yew, S; Yeo, A; Tan, C H

    2017-05-01

    To determine if there is a correlation between the cross-sectional areas (CSAs) in a single section and the volumes of muscles and fat in the thigh of sarcopenic and sarcopenic obesity (SO) populations using magnetic resonance imaging (MRI), and to assess the correlation between thigh MRI data and patient health status, i.e., normal, obese, sarcopenia, and SO. One hundred and ninety community-dwelling older adults were recruited and categorised into four subgroups based on Asian established criteria: normal, obese, sarcopenia, and SO. MRI images were acquired and muscles, subcutaneous fat (SF), and intermuscular fat (IMF) were automatically segmented in the thighs. Volumes of muscles and fat were calculated for the middle third of the thigh, while CSAs were assessed using a single section at 50% femur length. Correlation between CSA and volume were significantly high (p<0.001) for all components of muscle (0.907), SF (0.963), and IMF (0.939). Thigh CSA and volume both correlated significantly with a clinical diagnosis of normal, obesity, sarcopenia, and SO (p<0.03). A single CSA at 50% of femur length yields good estimation of muscle and fat volume in the thighs of older adults and correlates closely with the clinical criteria for sarcopenia and SO. This has the potential to greatly reduce costs, scan time, and post-processing time in clinical practice for the prediction of these conditions. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  13. Comparison of MRI and DXA to measure muscle size and age-related atrophy in thigh muscles.

    PubMed

    Maden-Wilkinson, T M; Degens, H; Jones, D A; McPhee, J S

    2013-09-01

    Magnetic resonance imaging (MRI) and dual-energy x-ray absorptiometry (DXA) were used to examine the thigh lean mass in young and old men and women. A whole-body DXA scan was used to estimate thigh lean mass in young (20 men; 22.4±3.1y; 18 women; 22.1±2.0y) and older adults (25 men; 72.3±4.9y; 28 women; 72.0±4.5y). Thigh lean mass determined with a thigh scan on the DXA or full thigh MRI scans were compared. Although the thigh lean mass quantified by DXA and MRI in young and older participants were correlated (R(2)=0.88; p<0.001) the magnitude of the differences in thigh lean mass between young and old was smaller with DXA than MRI (old vs. young men 79.5±13.1% and 73.4±11.2%; old vs. young women 88.6±11.8% and 79.4±12.3%, respectively). Detailed analysis of MRI revealed 30% smaller quadriceps muscles in the older than young individuals, while the other thigh muscles were only 18% smaller. DXA underestimates the age-related loss of thigh muscle mass in comparison to MRI. The quadriceps muscles were more susceptible to age-related atrophy compared with other thigh muscles.

  14. The influence of intracellular lactate and H+ on cell volume in amphibian skeletal muscle

    PubMed Central

    Usher-Smith, Juliet A; Fraser, James A; Bailey, Peter S J; Griffin, Julian L; Huang, Christopher L-H

    2006-01-01

    The combined effects of intracellular lactate and proton accumulation on cell volume, Vc, were investigated in resting Rana temporaria striated muscle fibres. Intracellular lactate and H+ concentrations were simultaneously increased by exposing resting muscle fibres to extracellular solutions that contained 20–80 mm sodium lactate. Cellular H+ and lactate entry was confirmed using pH-sensitive electrodes and 1H-NMR, respectively, and effects on Vc were measured using confocal microscope xz-scanning. Exposure to extracellular lactate up to 80 mm produced significant changes in pH and intracellular lactate (from a pH of 7.24 ± 0.03, n = 8, and 4.65 ± 1.07 mm, n = 6, respectively, in control fibres, to 6.59 ± 0.03, n = 4, and 26.41 ± 0.92 mm, n = 3, respectively) that were comparable to those observed following fatiguing stimulation (6.30–6.70 and 18.04 ± 1.78 mm, n = 6, respectively). Yet, the increase in intracellular osmolarity expected from such an increase in intracellular lactate did not significantly alter Vc. Simulation of these experimental results, modified from the charge difference model of Fraser & Huang, demonstrated that such experimental manoeuvres produced changes in intracellular [H+] and [lactate] comparable to those observed during muscle fatigue, and accounted for this paradoxical conservation of Vc through balancing negative osmotic effects resulting from the net cation efflux that would follow a titration of intracellular membrane-impermeant anions by the intracellular accumulation of protons. It demonstrated that with established physiological values for intracellular buffering capacity and the permeability ratio of lactic acid and anionic lactate, PLacH: PLac−, this would provide a mechanism that precisely balanced any effect on cell volume resulting from lactate accumulation during exercise. PMID:16613877

  15. Lateral pterygoid muscle volume and migraine in patients with temporomandibular disorders

    PubMed Central

    Lopes, Sérgio Lúcio Pereira de Castro; Costa, André Luiz Ferreira; Gamba, Thiago de Oliveira; Cruz, Adriana Dibo; Min, Li Li

    2015-01-01

    Purpose Lateral pterygoid muscle (LPM) plays an important role in jaw movement and has been implicated in Temporomandibular disorders (TMDs). Migraine has been described as a common symptom in patients with TMDs and may be related to muscle hyperactivity. This study aimed to compare LPM volume in individuals with and without migraine, using segmentation of the LPM in magnetic resonance (MR) imaging of the TMJ. Materials and Methods Twenty patients with migraine and 20 volunteers without migraine underwent a clinical examination of the TMJ, according to the Research Diagnostic Criteria for TMDs. MR imaging was performed and the LPM was segmented using the ITK-SNAP 1.4.1 software, which calculates the volume of each segmented structure in voxels per cubic millimeter. The chi-squared test and the Fisher's exact test were used to relate the TMD variables obtained from the MR images and clinical examinations to the presence of migraine. Logistic binary regression was used to determine the importance of each factor for predicting the presence of a migraine headache. Results Patients with TMDs and migraine tended to have hypertrophy of the LPM (58.7%). In addition, abnormal mandibular movements (61.2%) and disc displacement (70.0%) were found to be the most common signs in patients with TMDs and migraine. Conclusion In patients with TMDs and simultaneous migraine, the LPM tends to be hypertrophic. LPM segmentation on MR imaging may be an alternative method to study this muscle in such patients because the hypertrophic LPM is not always palpable. PMID:25793177

  16. Comparison in eccentric exercise-induced muscle damage among four limb muscles.

    PubMed

    Chen, Trevor C; Lin, Kun-Yi; Chen, Hsin-Lian; Lin, Ming-Ju; Nosaka, Kazunori

    2011-02-01

    This study tested the hypothesis that changes in indirect markers of muscle damage following maximal eccentric exercise would be smaller for the knee extensors (KE) and flexors (KF) compared with the elbow flexors (EF) and extensors (EE). A total of 17 sedentary men performed five sets of six maximal isokinetic (90° s(-1)) eccentric contractions of EF (range of motion, ROM: 90°-0°, 0 = full extension), EE (55°-145°), KF (90°-0°), and KE (30°-120°) using a different limb with a 4-5-week interval in a counterbalanced order. Changes in maximal isometric and concentric isokinetic strength, optimum angle, limb circumference, ROM, plasma creatine kinase activity and myoglobin concentration, muscle soreness, and echo-intensity of B-mode ultrasound images before and for 5 days following exercise were compared amongst the four exercises using two-way repeated-measures ANOVA. All variables changed significantly following EF, EE, and KF exercises, but KE exercise did not change the optimum angle, limb circumference, and echo-intensity. Compared with KF and KE, EF and EE showed significantly greater changes in all variables, without significant differences between EF and EE. Changes in all variables were significantly greater for KF than KE. For the same subjects, the magnitude of change in the dependent variables following exercise varied among the exercises. These results suggest that the two arm muscles are equally more susceptible to muscle damage than leg muscles, but KF is more susceptible to muscle damage than KE. The difference in the susceptibility to muscle damage seems to be associated with the use of muscles in daily activities.

  17. Comparison of gait before and after superficial trunk muscle exercise and deep trunk muscle exercise

    PubMed Central

    Kim, Hwanhee; Shim, Jemyung; Baek, Minho

    2015-01-01

    [Purpose] The purpose of this study was to examine the effects of superficial trunk muscle and deep trunk muscle exercise on gait. [Subjects] The subjects were 45 young adults who voluntarily consented to participate. The subjects were divided into a control group, a superficial muscle exercise group, and a deep muscle exercise group with 15 participants in each group. [Methods] Each group performed the exercises 5 times a week for 4 weeks. A Gait Analyzer was used to measure the subjects’ gait. A one-way ANOVA was conducted for analysis between each group. [Results] After 4 weeks, the values from right heel contact to foot flat, left foot flat to heel off, right foot flat to heel off, and left heel off to toe off significantly differed among the groups. [Conclusion] The superficial trunk muscle exercise improved stability, such as the period of mid stance during gait. The deep trunk muscle exercise improved mobility, such as heel contact to foot flat and heel off to toe off during gait. PMID:26696717

  18. Sheep carcass composition estimated from Longissimus thoracis et lumborum muscle volume measured by in vivo real-time ultrasonography.

    PubMed

    Silva, S R; Guedes, C M; Santos, V A; Lourenço, A L; Azevedo, J M T; Dias-da-Silva, A

    2007-08-01

    The use of Longissimus thoracis et lumborum muscle (LM) volume measured in vivo by real-time ultrasonography (RTU) to estimate carcass composition was evaluated in 47 female sheep. Animals were scanned over six sites (7th, 9th, 11th and 13th thoracic vertebrae and 2nd and 4th lumbar vertebrae). After slaughter carcass weight (CW) and composition by dissection were determined. RTU volume measurements were calculated by multiplying the LM area at each site by the vertebra lengths. Equivalent measurements to those taken in vivo were obtained on the carcass using a digital camera and image analysis. The correlation between LM volume measured by RTU and in the carcass was high for all scans. LM volume was better in predicting carcass muscle than carcass fat. Lower determination coefficients were obtained between LM volume and carcass tissues expressed in % of CW. The best estimates of carcass tissues weights and proportions were obtained using the LM volume between the 2nd and the 4th lumbar vertebrae for all tissues. Multiple regression equations were fitted using live weight (LW) and LM volume to predict carcass composition. For all tissues, the best fit was obtained with two, three or four independent variables and the stepwise procedure was consistent in selecting LW to establish the prediction equations. Weights and proportions of muscle, subcutaneous fat, intermuscular fat and total fat were accurately predicted. These results indicate that Longissimus thoracis et lumborum muscle volume measured in vivo by RTU can be used to predict sheep carcass composition (muscle and fat).

  19. Changes of orbital tissue volumes and proptosis in patients with thyroid extraocular muscle swelling after methylprednisolone pulse therapy.

    PubMed

    Higashiyama, Tomoaki; Nishida, Yasuhiro; Ohji, Masahito

    2015-11-01

    To evaluate the changes of orbital tissue volumes and proptosis after methylprednisolone pulse therapy in thyroid-associated ophthalmopathy (TAO). The cross-sectional areas of orbital tissues and proptosis were measured with magnetic resonance imaging in 40 orbits of 20 patients with TAO before and after methylprednisolone pulse therapy. The volumes of the whole orbit, orbital fatty tissue, and extraocular muscles were calculated. The volumes and proptosis were compared before and after treatment using a paired t test. Before treatment, the mean volumes were 33.0 ± 4.8 cm(3) in the whole orbit, 19.9 ± 4.1 cm(3) in the orbital fatty tissue, and 4.6 ± 1.2 cm(3) in the total extraocular muscles. After treatment, the mean volumes were 32.5 ± 4.4 cm(3) in the whole orbit, 19.9 ± 3.7 cm(3) in the orbital fatty tissue, and 4.0 ± 1.0 cm(3) in the total extraocular muscles. The mean volumes of the whole orbit (P = 0.17) and orbital fatty tissue (P = 0.82) were not significantly decreased after treatment, while the mean volume of total extraocular muscles was significantly decreased (P < 0.001). The mean proptosis value was 18.9 ± 2.8 mm before treatment and 18.6 ± 3.4 mm after treatment. The mean proptosis value was not significantly decreased after treatment (P = 0.30). The volume of orbital fatty tissue seemed to be unchanged after methylprednisolone pulse therapy while that of total extraocular muscles was decreased. The proptosis value seemed to be unchanged after treatment.

  20. Some properties of different skeletal muscle fiber types: comparison of reference bases.

    PubMed

    Kelso, T B; Hodgson, D R; Visscher, A R; Gollnick, P D

    1987-04-01

    Several biochemical components of the white portion of the gastrocnemius (WGM), plantaris (PM), and soleus (SM) muscles of the rat and middle gluteal (MGM) muscle of the horse were compared based on wet and dry weight, protein, and total creatine concentrations ([TCr]). The water content was similar for the rat hindlimb muscles, however, the concentrations of protein, ATP, phosphocreatine (PCr), creatine, and glycogen ranked as SM less than PM less than WGM for all reference bases except total creatine. In contrast, concentrations of ATP, creatine, and PCr were similar in all muscles studied when expressed as ratios of [TCr]. Horse MGM had the lowest percent of water and protein per gram wet or dry weight but highest glycogen concentration of the muscles studied, irrespective of the reference base used to express concentrations. Coefficients of variation were lowest when muscle constituents were related to [TCr]. It is concluded that expressing muscle constituents relative to total creatine results in the smallest variation and is a good method for making comparisons between muscles of similar fiber composition. However, essential information concerning different types of muscle may be lost when this reference base is used.

  1. Comparison of cervical muscle thickness between asymptomatic women with and without forward head posture.

    PubMed

    Bokaee, Fateme; Rezasoltani, Asghar; Manshadi, Farideh D; Naimi, Sedigheh S; Baghban, Alireza A; Azimi, Hadi

    Forward head posture (FHP) is a forward positioning of the head relative to the trunk in the sagittal plane. This posture is one of the most prevalent poor postures in patients with head and neck pain. Rehabilitative Ultrasound Imaging (RUSI) is a reliable method to objectively evaluate muscle thickness and function. To compare thickness of cervical muscles that control both head and neck posture between asymptomatic women with and without FHP. Seventy asymptomatic women aged between 20 and 40 years, with and without FHP (35 in each group), participated in the study. The thickness of the cervical muscles (rectus capitis posterior - RCP, oblique capitis superior - OCS, semispinalis capitis - SSC, sternocleidomastoid - SCM, and longus coli - LCo) was measured using RUSI and the data was compared between the two groups. The comparison of cervical muscle thickness between women with and without FHP revealed significant difference only with regard to the muscle thickness of the SCM muscle (mean difference: 0.7mm, 95% confidence interval of the difference: 0.14, 1.26mm, p value: 0.014). The thickness of this muscle was greater in women with FHP. Tonic contraction of the SCM muscle can lead to greater thickness of this muscle in subjects with FHP. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

  2. Time course of low- and high-volume strength training on neuromuscular adaptations and muscle quality in older women.

    PubMed

    Radaelli, Regis; Botton, Cíntia E; Wilhelm, Eurico N; Bottaro, Martim; Brown, Lee E; Lacerda, Fabiano; Gaya, Anelise; Moraes, Kelly; Peruzzolo, Amanda; Pinto, Ronei S

    2014-04-01

    This study investigated the effects of low- and high-volume strength trainings on neuromuscular adaptations of lower- and upper-body muscles in older women after 6 weeks (6WE), 13 weeks (13WE), and 20 weeks (20WE) of training. Healthy older women were assigned to low-volume (LV) or high-volume (HV) training groups. The LV group performed one set of each exercise, while the HV group performed three sets, 2 days/week. Knee extension and elbow flexion one-repetition maximum (1-RM), maximal isometric strength, maximal muscle activation, and muscle thickness (MT) of the lower- and upper-body muscles, as well as lower-body muscle quality (MQ) obtained by ultrasonography, were evaluated. Knee extension and elbow flexion 1-RM improved at all time points for both groups; however, knee extension 1-RM gains were greater for the HV group after 20WE. Maximal isometric strength of the lower body for both groups increased only at 20WE, while upper-body maximal isometric strength increased after 13WE and 20WE. Maximal activation of the lower and upper body for both groups increased only after 20WE. Both groups showed significant increases in MT of their lower and upper body, with greater gains in lower-body MT for the HV group at 20WE. MQ improved in both groups after 13WE and 20WE, whereas the HV group improved more than the LV group at 20WE. These results showed that low- and high-volume trainings have a similar adaptation time course in the muscular function of upper-body muscles. However, high-volume training appears to be more efficient for lower-body muscles after 20 weeks of training.

  3. Comparisons of different muscle metabolic enzymes and muscle fiber types in Jinhua and Landrace pigs.

    PubMed

    Guo, J; Shan, T; Wu, T; Zhu, L N; Ren, Y; An, S; Wang, Y

    2011-01-01

    Western and indigenous Chinese pig breeds show obvious differences in muscle growth and meat quality, however, the underlying molecular mechanism remains unclear. The main objective of this study was to evaluate the breed-specific mechanisms controlling meat quality and postmortem muscle metabolism. The specific purpose was to investigate the variations in meat quality, muscle fiber type, and enzyme activity between local Jinhua and exotic Landrace pigs at the same age (180 d of age), as well as the same BW of 64 kg, respectively. We compared differentially expressed muscle fiber types such as types I and IIa (oxidative), type IIb (glycolytic), as well as type IIx (intermediate) fibers in LM and soleus muscles of Jinhua and Landrace pigs using real-time reverse-transcription PCR. Furthermore, the metabolic enzyme activities of lactate dehydrogenase, as well as succinic dehydrogenase and malate dehydrogenase, were used as markers of glycolytic and oxidative capacities, respectively. Results showed that Jinhua pigs exhibited greater intramuscular fat content and less drip loss compared with the Landrace (P < 0.01). Meanwhile, the mRNA abundance of oxidative and intermediate fibers was increased in Jinhua pigs, whereas the glycolytic fibers were more highly expressed in the Landrace (P < 0.01). In addition, Jinhua pigs possessed greater oxidative capacity than that of the Landrace (P < 0.05). These results suggested that the increased expression of the oxidative and intermediate fibers and greater activities of oxidative enzymes in Jinhua pigs were related to meat quality as indicated by a greater intramuscular fat and reduced drip loss. Based on these results, we conclude that muscle fiber composition and postmortem muscle metabolism can explain, in part, the variation of meat quality in Jinhua and Landrace pigs. These results may provide valuable information for understanding the molecular mechanism responsible for breed specific differences in growth performance

  4. Comparison between alternating and pulsed current electrical muscle stimulation for muscle and systemic acute responses.

    PubMed

    Aldayel, Abdulaziz; Jubeau, Marc; McGuigan, Michael; Nosaka, Kazunori

    2010-09-01

    This study compared alternating current and pulsed current electrical muscle stimulation (EMS) for torque output, skin temperature (Tsk), blood lactate and hormonal responses, and skeletal muscle damage markers. Twelve healthy men (23-48 yr) received alternating current EMS (2.5 kHz delivered at 75 Hz, 400 micros) for the knee extensors of one leg and pulsed current (75 Hz, 400 micros) for the other leg to induce 40 isometric contractions (on-off ratio 5-15 s) at the knee joint angle of 100 degrees (0 degrees: full extension). The use of the legs for each condition was counterbalanced among subjects, and the two EMS bouts were separated by 2 wk. The current amplitude was consistently increased to maximally tolerable level, and the torque and perceived intensity were recorded over 40 isometric contractions. Tsk of the stimulated and contralateral knee extensors were measured before, during, and for 30 min after EMS. Blood lactate, growth hormone, testosterone, insulin-like growth factor 1, testosterone, and cortisol were measured before, during, and for 45 min following EMS. Muscle damage markers included maximal voluntary isometric contraction torque, muscle soreness with a 100-mm visual analog scale, and plasma creatine kinase (CK) activity, which were measured before and 1, 24, 48, 72, and 96 h after EMS. No significant differences in the torque induced during stimulation (approximately 30% maximal voluntary isometric contraction) and perceived intensity were found, and changes in Tsk, blood lactate, and hormones were not significantly different between conditions. However, all of the measures showed significant (P<0.05) changes from baseline values. Skeletal muscle damage was evidenced by prolonged strength loss, development of muscle soreness, and increases in plasma CK activity; however, the changes in the variables were not significantly different between conditions. It is concluded that acute effects of alternating and pulsed current EMS on the stimulated

  5. Osmolytes responsible for volume reduction under isosmotic or hypoosmotic conditions in Barnacle muscle cells.

    PubMed

    Peña-Rasgado, C; Pierce, S K; Rasgado-Flores, H

    2001-07-01

    In numerous animal cells, experimental manipulations that increase the intracellular free Ca2+ concentration induce cell volume reduction. This may occur under isosmotic conditions, e.g. when external Ca2+ (Ca(o)) is replaced by Mg2+ (42) or during exposure to hypoosmotic conditions (i.e. regulatory volume decrease, RVD) in the presence of Ca(o). We determined the osmolytes responsible for volume reduction under isosmotic and hypoosmotic conditions in barnacle muscle cells. Organic osmolytes (i.e. free amino acids and methylamines) and inorganic ions accounted for approximately 78% and 22% of the intracellular isosmotic activity, respectively. Isosmotic Ca(o) removal induced a net loss of KCI (with a ratio of 1K:1Cl) and free amino acids (FAA, mainly glycine and taurine). During RVD. the same ions (but in a proportion of 2K:1Cl) and FAA were lost. Since RVD was accompanied by extracellular alkalinization, the 2K:1Cl loss may be explained by the presence of a K+/H+ exchanger (or K+-OH- co-transporter) or Cl-/OH- exchanger. The lack of RVD in the absence of Ca(o) cannot be attributed to the loss of intracellular osmolytes during isosmotic Ca(o) removal because addition of Ca(o) during cell swelling promoted RVD.

  6. Muscle Volume Increases Following 16 Weeks of Resistive Exercise Training with the Advanced Resistive Exercise Device (ARED) and Free Weights

    NASA Technical Reports Server (NTRS)

    Nash, R. E.; Loehr, J. A.; Lee, S. M. C.; English, K. L.; Evans, H.; Smith, S. A.; Hagan, R. D.

    2009-01-01

    Space flight-induced muscle atrophy, particularly in the postural and locomotorymuscles, may impair task performance during long-duration space missions and planetary exploration. High intensity free weight (FW) resistive exercise training has been shown to prevent atrophy during bed rest, a space flight analog. NASA developed the Advanced Resistive Exercise Device (ARED) to simulate the characteristics of FW exercise (i.e. constant mass, inertial force) and to be used as a countermeasure during International Space Station (ISS) missions. PURPOSE: To compare the efficacy of ARED and FW training to induce hypertrophy in specific muscle groups in ambulatory subjects prior to deploying ARED on the ISS. METHODS: Twenty untrained subjects were assigned to either the ARED (8 males, 3 females) or FW (6 males, 3 females) group and participated in a periodizedtraining protocol consisting of squat (SQ), heel raise (HR), and deadlift(DL) exercises 3 d wk-1 for 16 wks. SQ, HR, and DL muscle strength (1RM) was measured before, after 8 wks, and after 16 wks of training to prescribe exercise and measure strength changes. Muscle volume of the vastigroup (V), hamstring group (H), hip adductor group (ADD), medial gastrocnemius(MG), lateral gastrocnemius(LG), and deep posterior muscles including soleus(DP) was measured using MRI pre-and post-training. Consecutive cross-sectional images (8 mm slices with a 2 mm gap) were analyzed and summed. Anatomical references insured that the same muscle sections were analyzed pre-and post-training. Two-way repeated measures ANOVAs (p<0.05) were used to test for differences in muscle strength and volume between training devices. RESULTS: SQ, HR, and DL 1RM increased in both FW (SQ: 49+/-6%, HR: 12+/-2%, DL: 23+/-4%) and ARED (SQ: 31+/-4%, HR: 18+/-2%, DL: 23+/-3%) groups. Both groups increased muscle volume in the V (FW: 13+/-2%, ARED: 10+/-2%), H (FW: 3+/-1%, ARED: 3+/-1 %), ADD (FW: 15=/-2%, ARED: 10+/-1%), LG (FW: 7+/-2%, ARED: 4+/-1%), MG (FW

  7. Effects of respiratory muscle unloading on leg muscle oxygenation and blood volume during high-intensity exercise in chronic heart failure.

    PubMed

    Borghi-Silva, Audrey; Carrascosa, Cláudia; Oliveira, Cristino Carneiro; Barroco, Adriano C; Berton, Danilo C; Vilaça, Debora; Lira-Filho, Edgar B; Ribeiro, Dirceu; Nery, Luiz Eduardo; Neder, J Alberto

    2008-06-01

    Blood flow requirements of the respiratory muscles (RM) increase markedly during exercise in chronic heart failure (CHF). We reasoned that if the RM could subtract a fraction of the limited cardiac output (QT) from the peripheral muscles, RM unloading would improve locomotor muscle perfusion. Nine patients with CHF (left ventricle ejection fraction = 26 +/- 7%) undertook constant-work rate tests (70-80% peak) receiving proportional assisted ventilation (PAV) or sham ventilation. Relative changes (Delta%) in deoxy-hemoglobyn, oxi-Hb ([O2Hb]), tissue oxygenation index, and total Hb ([HbTOT], an index of local blood volume) in the vastus lateralis were measured by near infrared spectroscopy. In addition, QT was monitored by impedance cardiography and arterial O2 saturation by pulse oximetry (SpO2). There were significant improvements in exercise tolerance (Tlim) with PAV. Blood lactate, leg effort/Tlim and dyspnea/Tlim were lower with PAV compared with sham ventilation (P < 0.05). There were no significant effects of RM unloading on systemic O2 delivery as QT and SpO2 at submaximal exercise and at Tlim did not differ between PAV and sham ventilation (P > 0.05). Unloaded breathing, however, was related to enhanced leg muscle oxygenation and local blood volume compared with sham, i.e., higher Delta[O2Hb]% and Delta[HbTOT]%, respectively (P < 0.05). We conclude that RM unloading had beneficial effects on the oxygenation status and blood volume of the exercising muscles at similar systemic O2 delivery in patients with advanced CHF. These data suggest that blood flow was redistributed from respiratory to locomotor muscles during unloaded breathing.

  8. Muscle sympathetic nerve activity and volume regulating factors in healthy pregnant and non-pregnant women.

    PubMed

    Charkoudian, Nisha; Usselman, Charlotte W; Skow, Rachel J; Staab, Jeffery S; Julian, Colleen Glyde; Stickland, Michael K; Chari, Radha S; Khurana, Rshmi; Davidge, Sandra T; Davenport, Margie H; Steinback, Craig D

    2017-07-21

    Healthy, normotensive human pregnancies are associated with striking increases in both plasma volume and vascular sympathetic nerve activity (SNA). In non-pregnant humans, volume regulatory factors including plasma osmolality, vasopressin and the renin-angiotensin-aldosterone system have important modulatory effects on control of sympathetic outflow. We hypothesized that pregnancy would be associated with changes in the relationships between SNA (measured as muscle SNA) and volume regulating factors, including plasma osmolality, plasma renin activity and arginine vasopressin (AVP). We studied 46 healthy, normotensive young women (23 pregnant and 23 non-pregnant). We measured SNA, arterial pressure, plasma osmolality, plasma renin activity, AVP and other volume regulatory factors in resting, semi-recumbent posture. Pregnant women had significantly higher resting SNA (38 ± 12 vs. non-pregnant: 23 ± 6 bursts/minute), lower osmolality and higher plasma renin activity and aldosterone (all P < 0.05). Group mean values for AVP were not different between groups (4.64 ± 2.57 [non-pregnant] vs. 5.17 ± 2.03 [pregnant], P > 0.05). However, regression analysis detected a significant relationship between individual values for SNA and AVP in pregnant (r = 0.71, P < 0.05) but not non-pregnant women (r = 0.04). No relationships were found for other variables. These data suggest that the link between AVP release and resting SNA becomes stronger in pregnancy, which may contribute importantly to blood pressure regulation in healthy women during pregnancy. Copyright © 2017, American Journal of Physiology-Heart and Circulatory Physiology.

  9. Epoxyeicosatrienoic acids mediate insulin-mediated augmentation in skeletal muscle perfusion and blood volume

    PubMed Central

    Shim, Chi Young; Kim, Sajeevani; Chadderdon, Scott; Wu, Melinda; Qi, Yue; Xie, Aris; Alkayed, Nabil J.; Davidson, Brian P.

    2014-01-01

    Skeletal muscle microvascular blood flow (MBF) increases in response to physiological hyperinsulinemia. This vascular action of insulin may facilitate glucose uptake. We hypothesized that epoxyeicosatrienoic acids (EETs), a family of arachadonic, acid-derived, endothelium-derived hyperpolarizing factors, are mediators of insulin's microvascular effects. Contrast-enhanced ultrasound (CEU) was performed to quantify skeletal muscle capillary blood volume (CBV) and MBF in wild-type and obese insulin-resistant (db/db) mice after administration of vehicle or trans-4-[4-(3-adamantan-1-ylureido)cyclohexyloxy]benzoic acid (t-AUCB), an inhibitor of soluble epoxide hydrolase that converts EETs to less active dihydroxyeicosatrienoic acids. Similar studies were performed in rats pretreated with l-NAME. CEU was also performed in rats undergoing a euglycemic hyperinsulinemic clamp, half of which were pretreated with the epoxygenase inhibitor MS-PPOH to inhibit EET synthesis. In both wild-type and db/db mice, intravenous t-AUCB produced an increase in CBV (65–100% increase at 30 min, P < 0.05) and in MBF. In db/db mice, t-AUCB also reduced plasma glucose by ∼15%. In rats pretreated with l-NAME, t-AUCB after produced a significant ≈20% increase in CBV, indicating a component of vascular response independent of nitric oxide (NO) production. Hyperinsulinemic clamp produced a time-dependent increase in MBF (19 ± 36 and 76 ± 49% at 90 min, P = 0.026) that was mediated in part by an increase in CBV. Insulin-mediated changes in both CBV and MBF during the clamp were blocked entirely by MS-PPOH. We conclude that EETs are a mediator of insulin-mediated augmentation in skeletal muscle perfusion and are involved in regulating changes in CBV during hyperinsulinemia. PMID:25336524

  10. Vascular smooth muscle contraction evoked by cell volume modulation: role of the cytoskeleton network.

    PubMed

    Koltsova, Svetlana V; Gusakova, Svetlana V; Anfinogenova, Yana J; Baskakov, Mikhail B; Orlov, Sergei N

    2008-01-01

    Previously, we reported that hyposmotic swelling evoked transient vascular smooth muscle cell (SMC) contraction that was completely abolished by L-type Ca(2+) channel blockers. In contrast, sustained contraction revealed in hyper- and isoosmotically-shrunken SMCs was insensitive to L-type channel blockers and was diminished in Ca(2+)-free medium by only 30-50%. Several research groups reported cell volume-dependent cytoskeleton network rearrangements. This study examines the role of cytoskeleton proteins in cell volume-dependent contraction of endothelium-denuded vascular smooth muscle rings (VSMR) from the rat thoracic aorta. Hyperosmotic shrinkage and hyposmotic swelling were triggered by modulation of medium osmolality; isosmotic shrinkage was induced by VSMR transfer from hypo- to isosmotic medium. The relative content of globular (G) and fibrillar (F) actin was estimated by fluorescence microscopy. Hyperosmotic shrinkage and hyposmotic swelling led to elevation of the F-actin/G-actin ratio by 2.5- and 1.8-fold respectively. Contraction of shrunken and swollen VSMR was insensitive to modulators of microtubules such as vinblastine, colchicine and docetaxel. Microfilament disassembly by cytochalasin B resulted in dramatic attenuation of the maximal amplitude of contraction of hyperosmotically-shrunken and hyposmotically-swollen VSMR, and almost completely abolished the contraction triggered by isosmotic shrinkage. These data suggest that both L-type Ca(2+) channel-mediated contraction of swollen vascular SMC and Ca(2+)(o)-insensitive contractions of shrunken cells are triggered by reorganization of the microfilament network caused by elevation of the F-actin/G-actin ratio.

  11. Comparison of a space shuttle flight (STS-78) and bed rest on human muscle function

    NASA Technical Reports Server (NTRS)

    Trappe, S. W.; Trappe, T. A.; Lee, G. A.; Widrick, J. J.; Costill, D. L.; Fitts, R. H.

    2001-01-01

    The purpose of this investigation was to assess muscle fiber size, composition, and in vivo contractile characteristics of the calf muscle of four male crew members during a 17-day spaceflight (SF; Life and Microgravity Sciences Spacelab Shuttle Transport System-78 mission) and eight men during a 17-day bed rest (BR). The protocols and timelines of these two investigations were identical, therefore allowing for direct comparisons between SF and the BR. The subjects' age, height, and weight were 43 +/- 2 yr, 183 +/- 4 cm, and 86 +/- 3 kg for SF and 43 +/- 2 yr, 182 +/- 3 cm, and 82 +/- 4 kg for BR, respectively. Calf muscle strength was examined before SF and BR; on days 2, 8, and 12 during SF and BR; and on days 2 and 8 of recovery. Muscle biopsies were obtained before and within 3 h after SF (gastrocnemius and soleus) and BR (soleus) before reloading. Maximal isometric calf strength and the force-velocity characteristics were unchanged with SF or BR. Additionally, neither SF nor BR had any effect on fiber composition or fiber size of the calf muscles studied. In summary, no changes in calf muscle strength and morphology were observed after the 17-day SF and BR. Because muscle strength is lost during unloading, both during spaceflight and on the ground, these data suggest that the testing sequence employed during the SF and BR may have served as a resistance training countermeasure to attenuate whole muscle strength loss.

  12. Comparison of a space shuttle flight (STS-78) and bed rest on human muscle function

    NASA Technical Reports Server (NTRS)

    Trappe, S. W.; Trappe, T. A.; Lee, G. A.; Widrick, J. J.; Costill, D. L.; Fitts, R. H.

    2001-01-01

    The purpose of this investigation was to assess muscle fiber size, composition, and in vivo contractile characteristics of the calf muscle of four male crew members during a 17-day spaceflight (SF; Life and Microgravity Sciences Spacelab Shuttle Transport System-78 mission) and eight men during a 17-day bed rest (BR). The protocols and timelines of these two investigations were identical, therefore allowing for direct comparisons between SF and the BR. The subjects' age, height, and weight were 43 +/- 2 yr, 183 +/- 4 cm, and 86 +/- 3 kg for SF and 43 +/- 2 yr, 182 +/- 3 cm, and 82 +/- 4 kg for BR, respectively. Calf muscle strength was examined before SF and BR; on days 2, 8, and 12 during SF and BR; and on days 2 and 8 of recovery. Muscle biopsies were obtained before and within 3 h after SF (gastrocnemius and soleus) and BR (soleus) before reloading. Maximal isometric calf strength and the force-velocity characteristics were unchanged with SF or BR. Additionally, neither SF nor BR had any effect on fiber composition or fiber size of the calf muscles studied. In summary, no changes in calf muscle strength and morphology were observed after the 17-day SF and BR. Because muscle strength is lost during unloading, both during spaceflight and on the ground, these data suggest that the testing sequence employed during the SF and BR may have served as a resistance training countermeasure to attenuate whole muscle strength loss.

  13. Static optimization of muscle forces during gait in comparison to EMG-to-force processing approach.

    PubMed

    Heintz, Sofia; Gutierrez-Farewik, Elena M

    2007-07-01

    Individual muscle forces evaluated from experimental motion analysis may be useful in mathematical simulation, but require additional musculoskeletal and mathematical modelling. A numerical method of static optimization was used in this study to evaluate muscular forces during gait. The numerical algorithm used was built on the basis of traditional optimization techniques, i.e., constrained minimization technique using the Lagrange multiplier method to solve for constraints. Measuring exact muscle forces during gait analysis is not currently possible. The developed optimization method calculates optimal forces during gait, given a specific performance criterion, using kinematics and kinetics from gait analysis together with muscle architectural data. Experimental methods to validate mathematical methods to calculate forces are limited. Electromyography (EMG) is frequently used as a tool to determine muscle activation in experimental studies on human motion. A method of estimating force from the EMG signal, the EMG-to-force approach, was recently developed by Bogey et al. [Bogey RA, Perry J, Gitter AJ. An EMG-to-force processing approach for determining ankle muscle forcs during normal human gait. IEEE Trans Neural Syst Rehabil Eng 2005;13:302-10] and is based on normalization of activation during a maximum voluntary contraction to documented maximal muscle strength. This method was adapted in this study as a tool with which to compare static optimization during a gait cycle. Muscle forces from static optimization and from EMG-to-force muscle forces show reasonably good correlation in the plantarflexor and dorsiflexor muscles, but less correlation in the knee flexor and extensor muscles. Additional comparison of the mathematical muscle forces from static optimization to documented averaged EMG data reveals good overall correlation to patterns of evaluated muscular activation. This indicates that on an individual level, muscular force patterns from mathematical

  14. COMPARISON OF SCAPULAR MUSCLE ACTIVATIONS DURING THREE OVERHEAD THROWING EXERCISES.

    PubMed

    Henning, Lisa; Plummer, Hillary; Oliver, Gretchen D

    2016-02-01

    With shoulder pain and injury on the rise in overhead athletes, clinicians are often examining preventative exercises to address functional abnormalities. Because shoulder impingement is prevalent in overhead athletes, much focus is on scapular stability and the function of the stabilizing force couple of the upper and lower trapezius and serratus anterior. The purpose of this study was to examine scapular muscle activation during a series of throws and holds (throwing without releasing) with two different ball weights (7oz and 12oz). It was hypothesized that the holds exercises would elicit greater activation of the scapular musculature than the throw, irrespective of ball weight. Case control laboratory study. Twenty-two NCAA Division I, right hand dominant, softball players (19.91 + 1.04 years; 169.24 + 7.36 cm; 72.09 + 10.61 kg) volunteered to participate. Surface EMG was utilized to measure muscle activity in the upper, middle and lower trapezius and serratus anterior muscles during three different throwing activities. MANOVA results revealed no significant differences in muscle activity between throwing conditions, F(16,82) = 1.02, p = 0.446, Wilks' Λ = 0.696, Cohen's d = 0.44 (7oz holds), 0.24 (12oz holds), power = 0.625. The results may provide some clinical insight in advocating the use of holds with different ball weights. The holds throw may be an effective step in shoulder strengthening that can more closely mimic the functional movement of throwing without the element of ball release. Level 3.

  15. Effects of swim training on lung volumes and inspiratory muscle conditioning.

    PubMed

    Clanton, T L; Dixon, G F; Drake, J; Gadek, J E

    1987-01-01

    Lung volumes and inspiratory muscle (IM) function tests were measured in 16 competitive female swimmers (age 19 +/- 1 yr) before and after 12 wk of swim training. Eight underwent additional IM training; the remaining eight were controls. Vital capacity (VC) increased 0.25 +/- 0.25 liters (P less than 0.01), functional residual capacity (FRC) increased 0.39 +/- 0.29 liters (P less than 0.001), and total lung capacity (TLC) increased 0.35 +/- 0.47 (P less than 0.025) in swimmers, irrespective of IM training. Residual volume (RV) did not change. Maximum inspiratory mouth pressure (PImax) measured at FRC changed -43 +/- 18 cmH2O (P less than 0.005) in swimmers undergoing IM conditioning and -29 +/- 25 (P less than 0.05) in controls. The time that 65% of prestudy PImax could be endured increased in IM trainers (P less than 0.001) and controls (P less than 0.05). All results were compared with similar IM training in normal females (age 21.1 +/- 0.8 yr) in which significant increases in PImax and endurance were observed in IM trainers only with no changes in VC, FRC, or TLC (Clanton et al., Chest 87: 62-66, 1985). We conclude that 1) swim training in mature females increases VC, TLC, and FRC with no effect on RV, and 2) swim training increases IM strength and endurance measured near FRC.

  16. Rest interval between resistance exercise sets: length affects volume but not creatine kinase activity or muscle soreness.

    PubMed

    Evangelista, Renato; Pereira, Rafael; Hackney, Anthony C; Machado, Marco

    2011-03-01

    To compare differences between two different rest interval lengths between sets on the volume completed, muscle damage and muscle soreness during a resistance exercise bout. Twenty-eight healthy sedentary men (18 ± 1 y old) volunteered to participate in this study and were divided into the 1 min (1RI; n = 14) or 3 min (3RI; n = 14) rest interval length between sets. They were submitted to maximal voluntary isometric contraction strength (MVC) and then performed a resistance exercise protocol constituted for three sets of biceps curl at 40% of MVC with 1 min (1RI group) or 3 min (3RI group) interval length between sets. Each bout was performed to voluntary fatigue and the workout volume completed was calculated. Subjects provided blood samples before each bout, and at 24, and 48 h following exercise to evaluate serum CK activity. Muscle soreness was analyzed through visual analog scale, which was presented to subjects before first bout, immediately after exercise protocol and at 24, and 48 h following exercise. The results demonstrated that the subjects with longer rest intervals provide greater workout volume as expected, but there were no differences in serum CK activity and muscle soreness between groups. Training with high-volume, low-intensity resistance training, exercising with short rest intervals does not appear to present any additional challenge to recovery in untrained subjects.

  17. Comparison of height-accumulation and volume-equation methods for estimating tree and stand volumes. Forest Service research note

    SciTech Connect

    Ferguson, R.B.; Baldwin, V.C.

    1995-09-01

    Estimating tree and stand volume in mature plantations is time consuming, involving much manpower and equipment; however, several sampling and volume-prediction techniques are available. This study showed that a well-constructed, volume-equation method yields estimates comparable to those of the often more time-consuming, hight-accumulation method, even though the latter should be more accurate for any individual tree. Plot volumes were estimated by both methods in a remeasurement of trees in a 40-plot, planted slash pine thinning study. The mean percent age difference in total volume, inside bark, between the two methods ranged from 1 to 2.5 percent across all the plots; differences outside bark ranged from 7 to 10 percent. The results were similar when the effecs of site, plot mean values, or tree-by-tree comparisons were incorporated.

  18. Comparison of contractile and extensile pneumatic artificial muscles

    NASA Astrophysics Data System (ADS)

    Pillsbury, Thomas E.; Wereley, Norman M.; Guan, Qinghua

    2017-09-01

    Pneumatic artificial muscles (PAMs) are used in robotic and prosthetic applications due to their high power to weight ratio, controllable compliance, and simple design. Contractile PAMs are typically used in traditional hard robotics in place of heavy electric motors. As the field of soft robotics grows, extensile PAMs are beginning to have increased usage. This work experimentally tests, models, and compares contractile and extensile PAMs to demonstrate the advantages and disadvantages of each type of PAM and applications for which they are best suited.

  19. Effects of dietary soy protein on skeletal muscle volume and strength in humans with various physical activities.

    PubMed

    Hashimoto, Rie; Sakai, Atsuko; Murayama, Masumi; Ochi, Arisa; Abe, Tomoki; Hirasaka, Katsuya; Ohno, Ayako; Teshima-Kondo, Shigetada; Yanagawa, Hiroaki; Yasui, Natsuo; Inatsugi, Mikiko; Doi, Daisuke; Takeda, Masanori; Mukai, Rie; Terao, Junji; Nikawa, Takeshi

    2015-01-01

    In recent years, the number of bedridden people is rapidly increasing due to aging or lack of exercise in Japan. This problem is becoming more serious, since there is no countermeasure against it. In the present study, we designed to investigate whether dietary proteins, especially soy, had beneficial effects on skeletal muscle in 59 volunteers with various physical activities. We subjected 59 volunteers with various physical activities to meal intervention examination. Persons with low and high physical activities were divided into two dietary groups, the casein diet group and the soy diet group. They ate daily meals supplemented with 7.8 g of powdered casein or soy protein isolate every day for 30 days. Bedridden patients in hospitals were further divided into three dietary groups: the no supplementation diet group, the casein diet group and the soy diet group. They were also subjected to a blood test, a urinalysis, magnetic resonance imaging analysis and muscle strength test of the knee before and after the meal intervention study. Thirty-day soy protein supplementation significantly increased skeletal muscle volume in participants with low physical activity, compared with 30-day casein protein supplementation. Both casein and soy protein supplementation increased the volume of quadriceps femoris muscle in bedridden patients. Consistently, soy protein significantly increased their extension power of the knee, compared with casein protein. Although casein protein increased skeletal muscle volume more than soy protein in bedridden patients, their muscle strength changes by soy protein supplementation were bigger than those by casein protein supplementation. The supplementation of soy protein would be one of the effective foods which prevent the skeletal muscle atrophy caused by immobilization or unloading.

  20. Strong relationships exist between muscle volume, joint power and whole-body external mechanical power in adults and children.

    PubMed

    O'Brien, Thomas D; Reeves, Neil D; Baltzopoulos, Vasilios; Jones, David A; Maganaris, Constantinos N

    2009-06-01

    The present study investigated whether differences between adults and children in mechanical power during single-joint knee extension tasks and the complex multijoint task of jumping could be explained by differences in the quadriceps femoris muscle volume. Peak power was calculated during squat jumps, from the integral of the vertical force measured by a force plate, and during concentric knee extensions at 30, 90, 120, 180 and 240 deg s(-1), and muscle volume was measured from magnetic resonance images for 10 men, 10 women, 10 prepubertal boys and 10 prepubertal girls. Peak power during jumping and isokinetic knee extension was significantly higher in men than in women, and in both adult groups compared with children (P < 0.01), although there were no differences between boys and girls. When power was normalized to muscle volume, the intergroup differences ceased to exist for both tasks. Peak power correlated significantly with quadriceps volume (P < 0.01), with r(2) values of 0.8, 0.86, 0.81, 0.78 and 0.81 from isokinetic knee extension at angular velocities of 30, 90, 120, 180 and 240 deg s(-1), respectively, and with an r(2) value of 0.9 from squat jumps. These results indicate that the quadriceps femoris muscle volume accounts largely for the increase in power that occurs with maturation in the two genders not only in kinematically constrained knee extensions but also in multijoint tasks. Future studies should examine the role of other factors relating to the generation and transmission of contractile power, such as muscle architecture, tendon stiffness and external mechanical leverage.

  1. Mitochondrial adaptations to high-volume exercise training are rapidly reversed after a reduction in training volume in human skeletal muscle.

    PubMed

    Granata, Cesare; Oliveira, Rodrigo S F; Little, Jonathan P; Renner, Kathrin; Bishop, David J

    2016-10-01

    Increased mitochondrial content and respiration have both been reported after exercise training. However, no study has directly compared how different training volumes influence mitochondrial respiration and markers of mitochondrial biogenesis. Ten healthy men performed high-intensity interval cycling during 3 consecutive training phases; 4 wk of normal-volume training (NVT; 3/wk), followed by 20 d of high-volume training (HVT; 2/d) and 2 wk of reduced-volume training (RVT; 5 sessions). Resting biopsy samples (vastus lateralis) were obtained at baseline and after each phase. No mitochondrial parameter changed after NVT. After HVT, mitochondrial respiration and citrate synthase activity (∼40-50%), as well as the protein content of electron transport system (ETS) subunits (∼10-40%), and that of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), NRF1, mitochondrial transcription factor A (TFAM), PHF20, and p53 (∼65-170%) all increased compared to baseline; mitochondrial specific respiration remained unchanged. After RVT, all the mitochondrial parameters measured except citrate synthase activity (∼36% above initial) were not significantly different compared to baseline (all P > 0.05). Our findings demonstrate that training volume is an important determinant of training-induced mitochondrial adaptations and highlight the rapid reversibility of human skeletal muscle to a reduction in training volume.-Granata, C., Oliveira, R. S. F., Little, J. P., Renner, K., Bishop, D. J. Mitochondrial adaptations to high-volume exercise training are rapidly reversed after a reduction in training volume in human skeletal muscle. © FASEB.

  2. Comparison of Statistically Modeled Contaminated Soil Volume Estimates and Actual Excavation Volumes at the Maywood FUSRAP Site - 13555

    SciTech Connect

    Moore, James; Hays, David; Quinn, John; Johnson, Robert; Durham, Lisa

    2013-07-01

    As part of the ongoing remediation process at the Maywood Formerly Utilized Sites Remedial Action Program (FUSRAP) properties, Argonne National Laboratory (Argonne) assisted the U.S. Army Corps of Engineers (USACE) New York District by providing contaminated soil volume estimates for the main site area, much of which is fully or partially remediated. As part of the volume estimation process, an initial conceptual site model (ICSM) was prepared for the entire site that captured existing information (with the exception of soil sampling results) pertinent to the possible location of surface and subsurface contamination above cleanup requirements. This ICSM was based on historical anecdotal information, aerial photographs, and the logs from several hundred soil cores that identified the depth of fill material and the depth to bedrock under the site. Specialized geostatistical software developed by Argonne was used to update the ICSM with historical sampling results and down-hole gamma survey information for hundreds of soil core locations. The updating process yielded both a best guess estimate of contamination volumes and a conservative upper bound on the volume estimate that reflected the estimate's uncertainty. Comparison of model results to actual removed soil volumes was conducted on a parcel-by-parcel basis. Where sampling data density was adequate, the actual volume matched the model's average or best guess results. Where contamination was un-characterized and unknown to the model, the actual volume exceeded the model's conservative estimate. Factors affecting volume estimation were identified to assist in planning further excavations. (authors)

  3. Scaling of maximal oxygen uptake by lower leg muscle volume in boys and men.

    PubMed

    Tolfrey, Keith; Barker, Alan; Thom, Jeanette M; Morse, Christopher I; Narici, Marco V; Batterham, Alan M

    2006-06-01

    The aim of this study was to critically examine the influence of body size on maximal oxygen uptake (VO2 max) in boys and men using body mass (BM), estimated fat-free mass (FFM), and estimated lower leg muscle volume (Vol) as the separate scaling variables. VO2 max and an in vivo measurement of Vol were assessed in 15 boys and 14 men. The FFM was estimated after percentage body fat had been predicted from population-specific skinfold measurements. By using nonlinear allometric modeling, common body size exponents for BM, FFM, and Vol were calculated. The point estimates for the size exponent (95% confidence interval) from the separate allometric models were: BM 0.79 (0.53-1.06), FFM 1.00 (0.78-1.22), and Vol 0.64 (0.40-0.88). For the boys, substantial residual size correlations were observed for VO2 max/BM0.79 and VO2 max/FFM1.00, indicating that these variables did not correctly partition out the influence of body size. In contrast, scaling by Vol0.64 led to no residual size correlation in boys or men. Scaling by BM is confounded by heterogeneity of body composition and potentially substantial differences in the mass exponent between boys and men. The FFM is precluded as an index of involved musculature because Vol did not represent a constant proportion of FFM [Vol proportional, variantFFM1.45 (95% confidence interval, 1.13-1.77)] in the boys (unlike the men). We conclude that Vol, as an indicator of the involved muscle mass, is the most valid allometric denominator for the scaling of VO2 max in a sample of boys and men heterogeneous for body size and composition.

  4. Comparison of Resistance Exercise Perceived Exertion and Muscle Activation at Varied Submaximal Durations, Loads, and Muscle Actions.

    PubMed

    Hollander, Daniel B; Worley, Jennifer R; Asoodeh, Mike; Wakesa, David; Magnuson, Matthew; Dantzler, Demetra K; Didier, Jennifer J; Kraemer, Robert R

    2017-05-01

    Hollander, DB, Worley, JR, Asoodeh, M, Wakesa, D, Magnuson, M, Dantzler, DK, Didier, JJ, and Kraemer, RR. Comparison of resistance exercise perceived exertion and muscle activation at varied submaximal durations, loads, and muscle actions. J Strength Cond Res 31(5): 1387-1394, 2017-Previous studies investigating muscle activation from dynamic, plate-loaded, concentric (CON) and eccentric (ECC) muscle contractions have not accounted for the greater absolute strength of ECC contractions. The purpose of the study was to determine the effect of different dynamic muscle contraction durations, loads, and contraction types (CON and ECC) on perceived exertion and muscle activation differences in 6 women (mean ± SD age, height, weight, body mass index 22.83 ± 2.56 years, 1.65 ± 0.261 m, 68.56 ± 2.72 kg, 25.26 ± 4.39 kg·m). The participants were recruited and trained to move weight at the appropriate duration (2, 3, 4, and 5 seconds) for leg extension using a displacement apparatus (sonic emitter, auditory) and a computer program (visual feedback of bar displacement). Concentric and ECC 1 repetition maximum (1RM) were determined for leg extension for the midrange 3-second duration. Thirty, 50, and 70% of either CON or ECC 1RM were loaded for the remainder of the sessions. Subjects were then assigned to complete trials in a counterbalanced fashion for load, contraction type, and contraction duration. Rating of perceived exertion (RPE) significantly increased in response to load (30, 50, and 70%) regardless of contraction type as did electromyography (EMG) root mean square amplitude. Greater time under tension significantly increased RPE regardless of contraction type during knee extension exercise. The EMG amplitude was less distinguishable between 2, 3, 4, and 5 seconds of contractions. The data highlight the effort sense distinctions made by women at submaximal exercise loads during knee extension. These findings should be used to develop effective resistance exercise

  5. Upper extremity muscle tone and response of tidal volume during manually assisted breathing for patients requiring prolonged mechanical ventilation

    PubMed Central

    Morino, Akira; Shida, Masahiro; Tanaka, Masashi; Sato, Kimihiro; Seko, Toshiaki; Ito, Shunsuke; Ogawa, Shunichi; Yokoi, Yuka; Takahashi, Naoaki

    2015-01-01

    [Purpose] The aim of the present study was to examine, in patients requiring prolonged mechanical ventilation, if the response of tidal volume during manually assisted breathing is dependent upon both upper extremity muscle tone and the pressure intensity of manually assisted breathing. [Subjects] We recruited 13 patients on prolonged mechanical ventilation, and assessed their upper extremity muscle tone using the modified Ashworth scale (MAS). The subjects were assigned to either the low MAS group (MAS≤2, n=7) or the high MAS group (MAS≥3, n=6). [Methods] The manually assisted breathing technique was applied at a pressure of 2 kgf and 4 kgf. A split-plot ANOVA was performed to compare the tidal volume of each pressure during manually assisted breathing between the low and the high MAS groups. [Results] Statistical analysis showed there were main effects of the upper extremity muscle tone and the pressure intensity of the manually assisted breathing technique. There was no interaction between these factors. [Conclusion] Our findings reveal that the tidal volume during the manually assisted breathing technique for patients with prolonged mechanical ventilation depends upon the patient’s upper extremity muscle tone and the pressure intensity. PMID:26357431

  6. Low- and high-volume strength training induces similar neuromuscular improvements in muscle quality in elderly women.

    PubMed

    Radaelli, Regis; Botton, Cíntia E; Wilhelm, Eurico N; Bottaro, Martim; Lacerda, Fabiano; Gaya, Anelise; Moraes, Kelly; Peruzzolo, Amanda; Brown, Lee E; Pinto, Ronei Silveira

    2013-08-01

    The aim of this study was to compare the effects of low- and high-volume strength training on strength, muscle activation and muscle thickness (MT) of the lower- and upper-body, and on muscle quality (MQ) of the lower-body in older women. Twenty apparently healthy elderly women were randomly assigned into two groups: low-volume (LV, n=11) and high-volume (HV, n=9). The LV group performed one-set of each exercise, while the HV group performed three-sets of each exercise, twice weekly for 13 weeks. MQ was measured by echo intensity obtained by ultrasonography (MQEI), strength per unit of muscle mass (MQST), and strength per unit of muscle mass adjusted with an allometric scale (MQAS). Following training, there was a significant increase (p≤0.001) in knee extension 1-RM (31.8±20.5% for LV and 38.3±7.3% for HV) and in elbow flexion 1-RM (25.1±9.5% for LV and 26.6±8.9% for HV) and in isometric maximal strength of the lower-body (p≤0.05) and upper-body (p≤0.001), with no difference between groups. The maximal electromyographic activation for both groups increased significantly (p≤0.05) in the vastus medialis and biceps brachii, with no difference between groups. All MT measurements of the lower- and upper-body increased similarly in both groups (p≤0.001). Similar improvements were also observed in MQEI (p≤0.01), MQST, and MQAS (p≤0.001) for both groups. These results demonstrate that low- and high-volume strength training promote similar increases in neuromuscular adaptations of the lower- and upper-body, and in MQ of the lower-body in elderly women.

  7. Quantitative assessment of brain volumes in fish: comparison of methodologies.

    PubMed

    Ullmann, Jeremy F P; Cowin, Gary; Collin, Shaun P

    2010-01-01

    When correlating brain areas with behavioral and environmental characteristics, a variety of techniques are employed. In fishes (elasmobranchs and teleosts), 2 methods, histology and the idealized ellipsoid and/or half-ellipsoid technique, are primarily used to calculate the volume of a brain area and therefore its relationship to social or ecological complexity. In this study on a perciform teleost, we have quantitatively compared brain volumes obtained using the conventional techniques of histology and approximating brain volume to an idealized ellipsoid (or half ellipsoid) and magnetic resonance imaging, an established clinical tool typically used for assessing brain volume in other vertebrates. Our results indicate that, when compared to brain volumes measured using magnetic resonance imaging of brain regions in situ, variations in brain shape and histological artifacts can lead to significant differences in brain volume, especially in the telencephalon and optic tecta. Consequently, in comparative studies of brain volumes, we advise caution when using the histological and/or ellipsoid methods to make correlations between brain area size and environmental, behavioral and social characteristics and, when possible, we propose the use of magnetic resonance imaging. Copyright © 2010 S. Karger AG, Basel.

  8. Comparison of orbital volume obtained by tomography and rapid prototyping.

    PubMed

    Roça, Guilherme Berto; Foggiatto, José Aguiomar; Ono, Maria Cecilia Closs; Ono, Sergio Eiji; da Silva Freitas, Renato

    2013-11-01

    This study aims to compare orbital volume obtained by helical tomography and rapid prototyping. The study sample was composed of 6 helical tomography scans. Eleven healthy orbits were identified to have their volumes measured. The volumetric analysis with the helical tomography utilized the same protocol developed by the Plastic Surgery Unit of the Federal University of Paraná. From the CT images, 11 prototypes were created, and their respective volumes were analyzed in 2 ways: using software by SolidWorks and by direct analysis, when the prototype was filled with saline solution. For statistical analysis, the results of the volumes of the 11 orbits were considered independent. The average orbital volume measurements obtained by the method of Ono et al was 20.51 cm, the average obtained by the SolidWorks program was 20.64 cm, and the average measured using the prototype method was 21.81 cm. The 3 methods demonstrated a strong correlation between the measurements. The right and left orbits of each patient had similar volumes. The tomographic method for the analysis of orbital volume using the Ono protocol yielded consistent values, and by combining this method with rapid prototyping, both reliability validations of results were enhanced.

  9. Lung volume recruitment acutely increases respiratory system compliance in individuals with severe respiratory muscle weakness

    PubMed Central

    Molgat-Seon, Yannick; Hannan, Liam M.; Dominelli, Paolo B.; Peters, Carli M.; Fougere, Renee J.; McKim, Douglas A.; Sheel, A. William

    2017-01-01

    The aim of the present study was to determine whether lung volume recruitment (LVR) acutely increases respiratory system compliance (Crs) in individuals with severe respiratory muscle weakness (RMW). Individuals with RMW resulting from neuromuscular disease or quadriplegia (n=12) and healthy controls (n=12) underwent pulmonary function testing and the measurement of Crs at baseline, immediately after, 1 h after and 2 h after a single standardised session of LVR. The LVR session involved 10 consecutive supramaximal lung inflations with a manual resuscitation bag to the highest tolerable mouth pressure or a maximum of 50 cmH2O. Each LVR inflation was followed by brief breath-hold and a maximal expiration to residual volume. At baseline, individuals with RMW had lower Crs than controls (37±5 cmH2O versus 109±10 mL·cmH2O−1, p<0.001). Immediately after LVR, Crs increased by 39.5±9.8% to 50±7 mL·cmH2O−1 in individuals with RMW (p<0.05), while no significant change occurred in controls (p=0.23). At 1 h and 2 h post-treatment, there were no within-group differences in Crs compared to baseline (all p>0.05). LVR had no significant effect on measures of pulmonary function at any time point in either group (all p>0.05). During inflations, mean arterial pressure decreased significantly relative to baseline by 10.4±2.8 mmHg and 17.3±3.0 mmHg in individuals with RMW and controls, respectively (both p<0.05). LVR acutely increases Crs in individuals with RMW. However, the high airway pressures during inflations cause reductions in mean arterial pressure that should be considered when applying this technique. PMID:28326313

  10. A COMPARISON OF STATIC AND DYNAMIC OPTIMIZATION MUSCLE FORCE PREDICTIONS DURING WHEELCHAIR PROPULSION

    PubMed Central

    Morrow, Melissa M.; Rankin, Jeffery W.; Neptune, Richard R.; Kaufman, Kenton R.

    2014-01-01

    The primary purpose of this study was to compare static and dynamic optimization muscle force and work predictions during the push phase of wheelchair propulsion. A secondary purpose was to compare the differences in predicted shoulder and elbow kinetics and kinematics and handrim forces. The forward dynamics simulation minimized differences between simulated and experimental data (obtained from 10 manual wheelchair users) and muscle co-contraction. For direct comparison between models, the shoulder and elbow muscle moment arms and net joint moments from the dynamic optimization were used as inputs into the static optimization routine. RMS errors between model predictions were calculated to quantify model agreement. There was a wide range of individual muscle force agreement that spanned from poor (26.4 % Fmax error in the middle deltoid) to good (6.4 % Fmax error in the anterior deltoid) in the prime movers of the shoulder. The predicted muscle forces from the static optimization were sufficient to create the appropriate motion and joint moments at the shoulder for the push phase of wheelchair propulsion, but showed deviations in the elbow moment, pronation-supination motion and hand rim forces. These results suggest the static approach does not produce results similar enough to be a replacement for forward dynamics simulations, and care should be taken in choosing the appropriate method for a specific task and set of constraints. Dynamic optimization modeling approaches may be required for motions that are greatly influenced by muscle activation dynamics or that require significant co-contraction. PMID:25282075

  11. Muscle torque in total knee arthroplasty: comparison of subvastus and midvastus approaches.

    PubMed

    Chang, Chih-Hung; Yang, Rong-Sen; Chen, Kuang-Ho; Liu, Tang-Kue; Chen, Wen-Chih; Ho, Yi-Ching; Hou, Sheng-Mou

    2010-07-01

    The subvastus and midvastus approaches are two of the most commonly performed quadriceps preserving approaches for total knee arthroplasty (TKA), which can hasten functional recovery and rehabilitation. However, there has not been sufficient investigation with respect to a quantitative comparison between the two approaches in terms of muscle strength. To compare outcomes with respect to muscle strength between these two approaches, quadriceps and hamstring muscle torques of 20 patients who underwent primary TKA with the subvastus (SV) approach and 10 patients who received the midvastus (MV) approach were measured after surgery. The median age of patients in the SV group (68 years, range 53-77 years) was significantly different that the median age of patients in the MV group (61 years, range 50-73 years) (P = 0.0141). There was no significant difference in patient weight, height, or postoperative duration before muscle testing between the SV and MV groups. There were no significant differences in peak muscle torque or hamstring/quadriceps (H/Q) ratio between the groups. We thus conclude peak muscle torque and H/Q ratios were not statistically different with the SV or MV approach, therefore functional outcome is comparable.

  12. Adolescent Volume Conservation Abilities: A Comparison of Three Tests.

    ERIC Educational Resources Information Center

    Protinsky, Howard O.; Hughston, George

    1980-01-01

    In a study to determine procedural effects of volume conservation tasks performed by adolescent females, the results revealed that the LaVatelli water displacement test was significantly more difficult than the Elkind test or Piaget's test. (Author/RL)

  13. Comparison of different precondtioners for nonsymmtric finite volume element methods

    SciTech Connect

    Mishev, I.D.

    1996-12-31

    We consider a few different preconditioners for the linear systems arising from the discretization of 3-D convection-diffusion problems with the finite volume element method. Their theoretical and computational convergence rates are compared and discussed.

  14. Comparison of volume estimation methods for pancreatic islet cells

    NASA Astrophysics Data System (ADS)

    Dvořák, JiřÃ.­; Å vihlík, Jan; Habart, David; Kybic, Jan

    2016-03-01

    In this contribution we study different methods of automatic volume estimation for pancreatic islets which can be used in the quality control step prior to the islet transplantation. The total islet volume is an important criterion in the quality control. Also, the individual islet volume distribution is interesting -- it has been indicated that smaller islets can be more effective. A 2D image of a microscopy slice containing the islets is acquired. The input of the volume estimation methods are segmented images of individual islets. The segmentation step is not discussed here. We consider simple methods of volume estimation assuming that the islets have spherical or ellipsoidal shape. We also consider a local stereological method, namely the nucleator. The nucleator does not rely on any shape assumptions and provides unbiased estimates if isotropic sections through the islets are observed. We present a simulation study comparing the performance of the volume estimation methods in different scenarios and an experimental study comparing the methods on a real dataset.

  15. Automatic assessment of volume asymmetries applied to hip abductor muscles in patients with hip arthroplasty

    NASA Astrophysics Data System (ADS)

    Klemt, Christian; Modat, Marc; Pichat, Jonas; Cardoso, M. J.; Henckel, Joahnn; Hart, Alister; Ourselin, Sebastien

    2015-03-01

    Metal-on-metal (MoM) hip arthroplasties have been utilised over the last 15 years to restore hip function for 1.5 million patients worldwide. Althoug widely used, this hip arthroplasty releases metal wear debris which lead to muscle atrophy. The degree of muscle wastage differs across patients ranging from mild to severe. The longterm outcomes for patients with MoM hip arthroplasty are reduced for increasing degrees of muscle atrophy, highlighting the need to automatically segment pathological muscles. The automated segmentation of pathological soft tissues is challenging as these lack distinct boundaries and morphologically differ across subjects. As a result, there is no method reported in the literature which has been successfully applied to automatically segment pathological muscles. We propose the first automated framework to delineate severely atrophied muscles by applying a novel automated segmentation propagation framework to patients with MoM hip arthroplasty. The proposed algorithm was used to automatically quantify muscle wastage in these patients.

  16. Comparison of actual tidal volume in neonatal lung model volume control ventilation using three ventilators.

    PubMed

    Toyama, H; Endo, Y; Ejima, Y; Matsubara, M; Kurosawa, S

    2011-07-01

    In neonates, small changes in tidal volumes (V(T)) may lead to complications. Previous studies have shown a significant difference between ventilator-measured tidal volume and tidal volume delivered (actual V(T)). We evaluated the accuracy of three different ventilators to deliver small V(T) during volume-controlled ventilation. We tested Servo 300, 840 ventilator and Evita 4 Neoflow ventilators with lung models simulating normal and injured neonatal lung compliance models. Gas volume delivered from the ventilator into the test circuit (V(TV)) and actual V(T) to the test lung were measured using Ventrak respiration monitors at set V(T) (30 ml). The gas volume increase of the breathing circuit was then calculated. Tidal volumes of the SV300 and PB840 in both lung models were similar to the set V(T) and the actual tidal volumes in the injured model (20.7 ml and 19.8 ml, respectively) were significantly less than that in the normal model (27.4 ml and 23.4 ml). PB840 with circuit compliance compensation could not improve the actual V(T). V(TV) of the EV4N in the normal and the injured models (37.8 ml and 46.6 ml) were markedly increased compared with set V(T), and actual V(T) were similar to set V(T) in the normal and injured model (30.2 ml and 31.9 ml, respectively). EV4N measuring V(T) close to the lung could match actual V(T) to almost the same value as the set V(T) however the gas volume of the breathing circuit was increased. If an accurate value for the patient's actual V(T) is needed, this V(T) must be measured by a sensor located between the Y-piece and the tracheal tube.

  17. In vivo MRI quantification of individual muscle and organ volumes for assessment of anabolic steroid growth effects.

    PubMed

    Wu, Ed X; Tang, Haiying; Tong, Christopher; Heymsfield, Steve B; Vasselli, Joseph R

    2008-04-01

    This study aimed to develop a quantitative and in vivo magnetic resonance imaging (MRI) approach to investigate the muscle growth effects of anabolic steroids. A protocol of MRI acquisition on a standard clinical 1.5 T scanner and quantitative image analysis was established and employed to measure the individual muscle and organ volumes in the intact and castrated guinea pigs undergoing a 16-week treatment protocol by two well-documented anabolic steroids, testosterone and nandrolone, via implanted silastic capsules. High correlations between the in vivo MRI and postmortem dissection measurements were observed for shoulder muscle complex (R=0.86), masseter (R=0.79), temporalis (R=0.95), neck muscle complex (R=0.58), prostate gland and seminal vesicles (R=0.98), and testis (R=0.96). Furthermore, the longitudinal MRI measurements yielded adequate sensitivity to detect the restoration of growth to or towards normal in castrated guinea pigs by replacing circulating steroid levels to physiological or slightly higher levels, as expected. These results demonstrated that quantitative MRI using a standard clinical scanner provides accurate and sensitive measurement of individual muscles and organs, and this in vivo MRI protocol in conjunction with the castrated guinea pig model constitutes an effective platform to investigate the longitudinal and cross-sectional growth effects of other potential anabolic steroids. The quantitative MRI protocol developed can also be readily adapted for human studies on most clinical MRI scanner to investigate the anabolic steroid growth effects, or monitor the changes in individual muscle and organ volume and geometry following injury, strength training, neuromuscular disorders, and pharmacological or surgical interventions.

  18. In Vivo MRI Quantification of Individual Muscle and Organ Volumes for Assessment of Anabolic Steroid Growth Effects

    PubMed Central

    Wu, Ed X.; Tang, Haiying; Tong, Christopher; Heymsfield, Steve B.; Vasselli, Joseph R.

    2015-01-01

    This study aimed to develop a quantitative and in vivo magnetic resonance imaging (MRI) approach to investigate the muscle growth effects of anabolic steroids. A protocol of MRI acquisition on a standard clinical 1.5 Tesla scanner and quantitative image analysis was established and employed to measure the individual muscle and organ volumes in the intact and castrated guinea pigs undergoing a 16-week treatment protocol by two well-documented anabolic steroids, testosterone and nandrolone, via implanted silastic capsules. High correlations between the in vivo MRI and postmortem dissection measurements were observed for shoulder muscle complex (R = 0.86), masseter (R=0.79), temporalis (R=0.95), neck muscle complex (R=0.58), prostate gland and seminal vesicles (R=0.98), and testis (R=0.96). Furthermore, the longitudinal MRI measurements yielded adequate sensitivity to detect the restoration of growth to or towards normal in castrated guinea pigs by replacing circulating steroid levels to physiological or slightly higher levels, as expected. These results demonstrated that quantitative MRI using a standard clinical scanner provides accurate and sensitive measurement of individual muscles and organs, and this in vivo MRI protocol in conjunction with the castrated guinea pig model constitutes an effective platform to investigate the longitudinal and cross-sectional growth effects of other potential anabolic steroids. The quantitative MRI protocol developed can also be readily adapted for human studies on most clinical MRI scanner to investigate the anabolic steroid growth effects, or monitor the changes in individual muscle and organ volume and geometry following injury, strength training, neuromuscular disorders, and pharmacological or surgical interventions. PMID:18241900

  19. Strength training at high versus low external resistance in older adults: effects on muscle volume, muscle strength, and force-velocity characteristics.

    PubMed

    Van Roie, Evelien; Delecluse, Christophe; Coudyzer, Walter; Boonen, Steven; Bautmans, Ivan

    2013-11-01

    Muscle adaptations can be induced by high-resistance exercise. Despite being potentially more suitable for older adults, low-resistance exercise protocols have been less investigated. We compared the effects of high- and low-resistance training on muscle volume, muscle strength, and force-velocity characteristics. Fifty-six older adults were randomly assigned to 12 weeks of leg press and leg extension training at either HIGH (2×10-15 repetitions at 80% of one repetition maximum (1RM)), LOW (1×80-100 repetitions at 20% of 1RM), or LOW+ (1×60 repetitions at 20% of 1RM, followed by 1×10-20 repetitions at 40% of 1RM). All protocols ended with muscle failure. Leg press and leg extension of 1RM were measured at baseline and post intervention and before the first training session in weeks 5 and 9. At baseline and post intervention, muscle volume (MV) was measured by CT-scan. A Biodex dynamometer evaluated knee extensor static peak torque in different knee angles (PT(stat90°), PT(stat120°), PT(stat150°)), dynamic peak torque at different speeds (PT(dyn60°s)(-1), PT(dyn180°s)(-1), PT(dyn240°s)(-1)), and speed of movement at 20% (S20), 40% (S40), and 60% (S60) of PTstat90°. HIGH and LOW+ resulted in greater improvements in 1RM strength than LOW (p<0.05). These differences were already apparent after week 5. Similar gains were found between groups in MV, PT(stat), PT(dyn60°s)(-1), and PT(dyn180°s)(-1). No changes were reported in speed of movement. HIGH tended to improve PT(dyn240°s)(-1) more than LOW or LOW+ (p=0.064). In conclusion, high- and low-resistance exercises ending with muscle failure may be similarly effective for hypertrophy. High-resistance training led to a higher increase in 1RM strength than low-resistance training (20% of 1RM), but this difference disappeared when using a mixed low-resistance protocol in which the resistance was intensified within a single exercise set (40% of 1RM). Our findings support the need for more research on low

  20. Magnetic resonance imaging with k-means clustering objectively measures whole muscle volume compartments in sarcopenia/cancer cachexia.

    PubMed

    Gray, Calum; MacGillivray, Thomas J; Eeley, Clare; Stephens, Nathan A; Beggs, Ian; Fearon, Kenneth C; Greig, Carolyn A

    2011-02-01

    Sarcopenia and cachexia are characterized by infiltration of non-contractile tissue within muscle which influences area and volume measurements. We applied a statistical clustering (k-means) technique to magnetic resonance (MR) images of the quadriceps of young and elderly healthy women and women with cancer to objectively separate the contractile and non-contractile tissue compartments. MR scans of the thigh were obtained for 34 women (n = 16 young, (median) age 26 y; n = 9 older, age 80 y; n = 9 upper gastrointestinal cancer patients, age 65 y). Segmented regions of consecutive axial images were used to calculate cross-sectional area and (gross) volume. The k-means unsupervised algorithm was subsequently applied to the MR binary mask image array data with resultant volumes compared between groups. Older women and women with cancer had 37% and 48% less quadriceps muscle respectively than young women (p < 0.001). Application of k-means subtracted a significant 9%, 14% and 20% non-contractile tissue from the quadriceps of young, older and patient groups respectively (p < 0.001). There was a significant effect of group (i.e., cancer vs healthy) when controlling for age as a covariate (p = 0.003). K-means objectively separates contractile and non-contractile tissue components. Women with upper GI cancer have significant fatty infiltration throughout whole muscle groups which is maintained when controlling for age. Copyright © 2010 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  1. Comparison of respiratory muscles activity and exercise capacity in patients with idiopathic scoliosis and healthy individuals.

    PubMed

    Mohammadi, Pirayeh; Akbari, Mohammad; Sarrafzadeh, Javad; Moradi, Zahra

    2014-11-01

    Idiopathic scoliosis causes respiratory muscles weakness and reduced exercise capacity. However, the mechanism of these symptoms is still unknown. The main objective of this study was to determine the intensity of respiratory muscle activity and exercise capacity in patients with idiopathic scoliosis in comparison with healthy people. In this study, 20 female patients with adult idiopathic scoliosis (10 mild and 10 moderate) as well as 10 healthy matched individuals with characteristics of the patients were selected. The subjects were fatigued through a maximal incremental cycle ergometry protocol. Meanwhile, the electromyography values of the external intercostal muscles and diaphragm were recorded bilaterally, and fatigue duration was determined. The root mean square of concave external intercostal muscles and concave diaphragm in patients with idiopathic scoliosis was significantly reduced during the fatiguing exercise protocol compared with healthy individuals. The median frequencies of the two sides differed significantly and were lower in patients with moderate scoliosis than healthy subjects. Fatigue duration (minutes) also was lower in patients with moderate scoliosis than healthy subjects. Scoliosis causes respiratory muscle weakness and reduced fatigue duration in response to mild physical activity compared with healthy subjects and these dysfunctions appear to be related to the severity of scoliosis curvature (moderate > mild).

  2. Electromyographical Comparison of Muscle Activation Patterns Across Three Commonly Performed Kettlebell Exercises.

    PubMed

    Lyons, Brian C; Mayo, Jerry J; Tucker, W Steven; Wax, Ben; Hendrix, Russell C

    2017-09-01

    Lyons, BC, Mayo, JJ, Tucker, WS, Wax, B, and Hendrix, RC. Electromyographical comparison of muscle activation patterns across 3 commonly performed kettlebell exercises. J Strength Cond Res 31(9): 2363-2370, 2017-The purpose of this study was to compare the muscle activation patterns of 3 different kettlebell (KB) exercises using electromyography (EMG). Fourteen resistance-trained subjects completed a 1-arm swing (Swing), 1-arm swing style snatch (Snatch), and a 1-arm clean (Clean) using a self-selected 8 to 10 repetition maximum load for each exercise. Trial sessions consisted of subjects performing 5 repetitions of each KB exercise. Mean EMG was used to assess the muscle activation of the biceps brachii, anterior deltoid, posterior deltoid, erector spinae (ES), vastus lateralis (VL), biceps femoris, contralateral external oblique (EO), and gluteus maximus during each lift using surface electrodes. The mean EMG was normalized using maximal voluntary contractions obtained from manual muscle testing. Repeated-measures analysis of variance revealed a significant difference in the muscle activation patterns of the ES (Swing > Snatch), EO (Snatch, Clean > Swing), and VL (Swing > Clean) across the 3 KB exercises. We conclude that although the KB Swing, Snatch, and Clean are total body exercises, they place different demands on the ES, contralateral EO, and the VL. Therefore, KBs represent an authentic alternative for lifters, and the Swing, Snatch, and Clean are not redundant exercises.

  3. Comparison of optical dendrometers for prediction of standing tree volume

    Treesearch

    Robert C. Parker; Thomas G. Matney

    2000-01-01

    Enhanced sets of compatible stem profile equations were used with data collected from felled and standing pine trees to calculate tree volumes to various top merchantability limits. Standing trees were measured with the Criterion 400 Laser, Tele-Relaskop, and Wheeler Pentaprism. These measurements were used to compare accuracies of the optical dendrometers for the...

  4. Effect of isosmotic removal of extracellular Ca2+ and of membrane potential on cell volume in muscle cells.

    PubMed

    Peña-Rasgado, C; McGruder, K D; Summers, J C; Rasgado-Flores, H

    1994-09-01

    Isosmotic removal of extracellular Ca2+ (Cao) and changes in membrane potential (Vm) are frequently performed manipulations. Using isolated voltage-clamped barnacle muscle cells, we studied the effect of these manipulations on isosmotic cell volume. Replacing Cao by Mg2+ induced 1) verapamil-sensitive extracellular Na(+)-dependent membrane depolarization, 2) membrane depolarization-dependent cell volume reduction in cells whose sarcoplasmic reticulum (SR) was presumably loaded with Ca2+ [intracellular Ca2+ (Cai)-loaded cells], and 3) cell volume increase in cells whose SR was presumably depleted of Ca2+ (Cai-depleted cells) or in Cai-loaded cells whose Vm was held constant. Membrane depolarization induced 1) volume reduction in Cai-loaded cells or 2) verapamil-sensitive volume increase in Cai-depleted cells. This suggests tha, in Cai-loaded cells, membrane depolarization induces SR Ca2+ release, which in turn promotes volume reduction. Conversely, in Cai-depleted cells, the depolarization activates Na+ influx through a verapamil-sensitive pathway leading to the volume increase. This pathway is also revealed when Cao is removed in either Cai-depleted cells or in cells whose Vm is held constant.

  5. 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.

  6. Change in Psoas Muscle Volume as a Predictor of Outcomes in Patients Treated with Chemotherapy and Radical Cystectomy for Muscle-Invasive Bladder Cancer

    PubMed Central

    Zargar, Homayoun; Almassi, Nima; Kovac, Evan; Ercole, Cesar; Remer, Erick; Rini, Brian; Stephenson, Andrew; Garcia, Jorge A.; Grivas, Petros

    2017-01-01

    Objective: Sarcopenia, or the age-related loss of skeletal muscle mass and function, has been investigated as a potential marker of adverse outcomes among surgical patients. Our aim was to assess for changes in psoas muscle volume (PMV) following administration of neoadjuvant chemotherapy (NAC) in patients with bladder cancer and to examine whether changes in PMV following NAC are predictive of perioperative complications, pathologic response or survival. Methods: During the period of 2009–2013, patients undergoing NAC and radical cystectomy (RC) at our institution with pre and post NAC cross sectional images available were included. Bilateral total psoas muscle volume (PMV) was obtained from pre- and post- NAC images and the proportion of PMV change was calculated by dividing the change PMV by pre-NAC PMV. Analyses for the assessment of factors predicting PMV loss, partial/complete pathologic response (pPR/pCR), complications, readmission, cancer specific (CSS), recurrence-free (RFS) and overall survival (OS) were performed. Results: Total of 60 patients had complete radiological data available. Post-NAC PMV and BMI declines were statistically significant, 4.9% and 0.05%, respectively. NAC dose reduction/delay was a significant predictor of PMV loss (coefficient B 4.6; 95% CI 0.05–9.2; p = 0.047). The proportion of PMV decline during NAC was not a predictor of pPR, pCR, complications, readmission, CSS, RFS, or OS. Conclusions: We observed an interval decline in PMV during the period of NAC administration and this decline was more than it could be appreciated with changes in BMI during the same period. PMV decline was associated with the need for dose reduction/dose delay during NAC. In our series, PMV changes occurring during NAC administration were not predictive of pathologic response to chemotherapy, postoperative complications or survival. PMID:28149936

  7. TETAM Model Verification Study. Volume 3. Dynamic Battle Comparisons

    DTIC Science & Technology

    1976-02-01

    there were 21 unpaired firings by five of the tanks. The large number of unpaired firings clouds any comparisons. (This level of unpaired...mmoinomminifv ■j-J-in-j-msj-^^vr inLnmininininmin <-> oorT >r’^i«o*(t)«yjf*rr)>,T es •• o o o» »> I I I I ) I I I I I I

  8. KEY COMPARISON: EURAMET regional key comparison EURAMET.M.FF-K4.b: Volume intercomparison at 20 L

    NASA Astrophysics Data System (ADS)

    Batista, Elsa; Lau, Peter

    2009-01-01

    In the sequence of CIPM key comparisons concerning volume calibrations an interregional comparison CCM.FF-K4 was performed between December 2003 and March 2005 for volume standards of 20 L and 100 mL. The corresponding regional part of this comparison within Europe was performed in 2006 for a 100 mL Gay-Lussac Pycnometer—EUROMET.M.FF-K4 (EUROMET project number 692). It was decided during the EUROMET meeting in Istanbul 2007 to also perform the regional part of this key comparison at 20 L, as EURAMET.M.FF-K4.b (EURAMET project number 1008). This comparison was guided by IPQ (Portugal) with SP (Sweden) acting has the pilot laboratory having taken part in the interregional exercise. Fourteen countries decided to participate in this comparison. One of three 20 L pipettes, 710-04FyV used in the CCM.FF K4, was readjusted by CENAM (Mexico), which initiated this key comparison and produced the transfer standard. The main purpose of this project was to compare the experimental results and uncertainty calculations in calibrating this 20 L pipette and linking the intra-regional European results with the results obtained in the previous inter-regional CIPM key comparison. The results of all laboratories participating in EURAMET project 1008 are presented in this report as well as their equivalence with the reference value of the key comparison CCM.FF-K4. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  9. Effect of change in blood volume in skin plus active muscle on heart rate drift during submaximal exercise.

    PubMed

    Yano, T; Yunoki, T; Matsuura, R; Arimitsu, T; Kimura, T

    2008-12-01

    The purpose of the present study was to examine the effect of change in blood volume in skin plus active muscle on heart rate drift during moderate exercise and heavy exercise for 30 min. Total hemoglobin concentration (Total Hb) in the vastus lateralis muscle plus its skin was determined by near-infrared spectroscopy. Total Hb significantly increased and remained stable from 20 min in moderate exercise and from 10 min in heavy exercise. Heart rate (HR) rapidly increased until 3 min and showed a steady state in moderate exercise. HR at 30 min was significantly higher than that at 3 min in moderate exercise. HR rapidly increased until 3 min and then gradually but significantly increased in heavy exercise. Increase in total Hb was not significantly related with HR after 3 min of exercise when HR was around 120 beats per min in moderate exercise. Increase in total Hb was significantly related with HR from 3 min to 10 min in the heavy exercise (correlation coefficients ranged from 0.959 to 0.702). It is concluded that an increase in the blood volume in skin plus active muscle is not simply associated with HR drift.

  10. Comparison of magnetic field and electric potential produced by frog heart muscle

    NASA Astrophysics Data System (ADS)

    Burstein, Deborah; Cohen, David

    1985-04-01

    A comparison is made here between the magnetic field and electric potential produced by a thin strip of frog heart muscle. An experimental test is made of the theory which states that the wave front of a single fiber (or parallel bundle of fibers as in this strip) can be represented, for both the magnetic field and electric potential, by the same single-current dipole. First, an experimental measurement is made of the ratio of magnetic field/electric potential produced by an actual current dipole in an electrolytic tank. Then the dipole is replaced by the muscle strip and a measurement is again made of the ratio; this is done for three muscle strips at eight different source-to-detector distances ranging from 1 to 5 cm. It is found, in all cases, that the muscle ratios are equal to those of the actual dipole to within the experimental uncertainty of ±10%. Therefore, to this extent the theory is verified for this case of a thin strip of frog heart tissue.

  11. 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.

  12. Deltoid muscle volume affects clinical outcome of reverse total shoulder arthroplasty in patients with cuff tear arthropathy or irreparable cuff tears

    PubMed Central

    Yoon, Jong Pil; Seo, Anna; Kim, Jeong Jun; Lee, Chang-Hwa; Baek, Seung-Hun; Kim, Shin Yoon; Jeong, Eun Taek; Oh, Kyung-Soo

    2017-01-01

    We aimed to estimate the interrelation between preoperative deltoid muscle status by measuring the 3-dimensional deltoid muscle volume and postoperative functional outcomes after reverse total shoulder arthroplasty(RTSA). Thirty-five patients who underwent RTSA participated in this study. All patients underwent preoperative magnetic resonance imaging(MRI) as well as pre- and postoperative radiography and various functional outcome evaluations at least 1 year. The primary outcome parameter was set as age- and sex-matched Constant scores. The 3-dimensional deltoid muscle model was generated using a medical image processing software and in-house code, and the deltoid muscle volume was calculated automatically. Various clinical and radiographic factors comprising the deltoid muscle volume adjusted for body mass index(BMI) were analyzed, and their interrelation with the outcome parameters was appraised using a multivariate analysis. As a result, all practical consequences considerably improved following surgery(all p<0.01). Overall, 20 and 15 indicated a higher and a lower practical consequence than the average, respectively, which was assessed by the matched Constant scores. The deltoid muscle volume adjusted for BMI(p = 0.009), absence of a subscapularis complete tear (p = 0.040), and greater change in acromion-deltoid tuberosity distance(p = 0.013) were associated with higher matched Constant scores. Multivariate analysis indicated that the deltoid muscle volume was the single independent prognostic factor for practical consequences(p = 0.011). In conclusion, the preoperative deltoid muscle volume significantly affected the functional outcome following RTSA in patients with cuff tear arthropathy or irreparable cuff tears. Therefore, more attention should be paid to patients with severe atrophied deltoid muscle who are at a high risk for poor practical consequences subsequent to RTSA. PMID:28355234

  13. Deltoid muscle volume affects clinical outcome of reverse total shoulder arthroplasty in patients with cuff tear arthropathy or irreparable cuff tears.

    PubMed

    Yoon, Jong Pil; Seo, Anna; Kim, Jeong Jun; Lee, Chang-Hwa; Baek, Seung-Hun; Kim, Shin Yoon; Jeong, Eun Taek; Oh, Kyung-Soo; Chung, Seok Won

    2017-01-01

    We aimed to estimate the interrelation between preoperative deltoid muscle status by measuring the 3-dimensional deltoid muscle volume and postoperative functional outcomes after reverse total shoulder arthroplasty(RTSA). Thirty-five patients who underwent RTSA participated in this study. All patients underwent preoperative magnetic resonance imaging(MRI) as well as pre- and postoperative radiography and various functional outcome evaluations at least 1 year. The primary outcome parameter was set as age- and sex-matched Constant scores. The 3-dimensional deltoid muscle model was generated using a medical image processing software and in-house code, and the deltoid muscle volume was calculated automatically. Various clinical and radiographic factors comprising the deltoid muscle volume adjusted for body mass index(BMI) were analyzed, and their interrelation with the outcome parameters was appraised using a multivariate analysis. As a result, all practical consequences considerably improved following surgery(all p<0.01). Overall, 20 and 15 indicated a higher and a lower practical consequence than the average, respectively, which was assessed by the matched Constant scores. The deltoid muscle volume adjusted for BMI(p = 0.009), absence of a subscapularis complete tear (p = 0.040), and greater change in acromion-deltoid tuberosity distance(p = 0.013) were associated with higher matched Constant scores. Multivariate analysis indicated that the deltoid muscle volume was the single independent prognostic factor for practical consequences(p = 0.011). In conclusion, the preoperative deltoid muscle volume significantly affected the functional outcome following RTSA in patients with cuff tear arthropathy or irreparable cuff tears. Therefore, more attention should be paid to patients with severe atrophied deltoid muscle who are at a high risk for poor practical consequences subsequent to RTSA.

  14. Comparison of incremental and constant load tests of inspiratory muscle endurance in COPD.

    PubMed

    Hill, K; Jenkins, S C; Philippe, D L; Shepherd, K L; Hillman, D R; Eastwood, P R

    2007-09-01

    The aim of the present study was to determine the relative value of incremental and constant load tests in detecting changes in inspiratory muscle endurance following high-intensity inspiratory muscle training (H-IMT) in chronic obstructive pulmonary disease. In total, 16 subjects (11 males; forced expiratory volume in one second (FEV(1)) 37.4+/-12.5%) underwent H-IMT. In addition, 17 subjects (11 males; FEV(1) 36.5+/-11.5%) underwent sham inspiratory muscle training (S-IMT). Training took place three times a week for 8 weeks. Baseline and post-training measurements were obtained of maximum threshold pressure sustained during an incremental load test (P(th,max)) and time breathing against a constant load (t(lim)). Breathing pattern was unconstrained. H-IMT increased P(th,max) and t(lim) relative to baseline and to any change seen following S-IMT. The effect size for P(th,max) was greater than for t(lim). Post-training tests were accompanied by changes in breathing pattern, including decreased duty cycle, which may have served to decrease inspiratory work and thereby contribute to the increase in P(th,max) and t(lim) in both groups. When assessing inspiratory muscle function in chronic obstructive pulmonary disease via tests in which the pattern of breathing is unconstrained, the current authors recommend incremental load tests be used in preference to constant load tests. However, to attribute changes in these tests to improvements in inspiratory muscle endurance, breathing pattern should be controlled.

  15. Comparison of Cerebral Blood Volume and Plasma Volume in Untreated Intracranial Tumors

    PubMed Central

    Ramalho, Joana; Eldeniz, Cihat; An, Hongyu; Lee, Yueh Z.

    2016-01-01

    Purpose Plasma volume and blood volume are imaging-derived parameters that are often used to evaluation intracranial tumors. Physiologically, these parameters are directly related, but their two different methods of measurements, T1-dynamic contrast enhanced (DCE)- and T2-dynamic susceptibility contrast (DSC)-MR utilize different model assumptions and approaches. This poses the question of whether the interchangeable use of T1-DCE-MRI derived fractionated plasma volume (vp) and relative cerebral blood volume (rCBV) assessed using DSC-MRI, particularly in glioblastoma, is reliable, and if this relationship can be generalized to other types of brain tumors. Our goal was to examine the hypothetical correlation between these parameters in three most common intracranial tumor types. Methods Twenty-four newly diagnosed, treatment naïve brain tumor patients, who had undergone DCE- and DSC-MRI, were classified in three histologically proven groups: glioblastoma (n = 7), meningioma (n = 9), and intraparenchymal metastases (n = 8). The rCBV was obtained from DSC after normalization with the normal-appearing anatomically symmetrical contralateral white matter. Correlations between these parameters were evaluated using Pearson (r), Spearman's (ρ) and Kendall’s tau-b (τB) rank correlation coefficient. Results The Pearson, Spearman and Kendall’s correlation between vp with rCBV were r = 0.193, ρ = 0.253 and τB = 0.33 (p-Pearson = 0.326, p-Spearman = 0.814 and p-Kendall = 0.823) in glioblastoma, r = -0.007, ρ = 0.051 and τB = 0.135 (p-Pearson = 0.970, p-Spearman = 0.765 and p-Kendall = 0.358) in meningiomas, and r = 0.289, ρ = 0.228 and τB = 0.239 (p-Pearson = 0.109, p-Spearman = 0.210 and p-Kendall = 0.095) in metastasis. Conclusion Results indicate that no correlation exists between vp with rCBV in glioblastomas, meningiomas and intraparenchymal metastatic lesions. Consequently, these parameters, as calculated in this study, should not be used interchangeably in

  16. Postmaximal contraction blood volume responses are blunted in obese and type 2 diabetic subjects in a muscle-specific manner.

    PubMed

    Sanchez, Otto A; Copenhaver, Elizabeth A; Chance, Marti A; Fowler, Michael J; Towse, Theodore F; Kent-Braun, Jane A; Damon, Bruce M

    2011-08-01

    The purpose of this study was to determine whether there are differences in postisometric contraction blood volume and oxygenation responses among groups of type 2 diabetes mellitus (T2DM), obese, and lean individuals detectable using MRI. Eight T2DM patients were individually matched by age, sex, and race to non-T2DM individuals with similar body mass index (obese) and lean subjects. Functional MRI was performed using a dual-gradient-recalled echo, echo-planar imaging sequence with a repetition time of 1 s and at two echo times (TE = 6 and 46 ms). Data were acquired before, during, and after 10-s isometric dorsiflexion contractions performed at 50 and 100% of maximal voluntary contraction (MVC) force. MRI signal intensity (SI) changes from the tibialis anterior and extensor digitorum longus muscles were plotted as functions of time for each TE. From each time course, the difference between the minimum and the maximum postcontraction SI (ΔSI) were determined for TE = 6 ms (ΔSI(6)) and TE = 46 ms (ΔSI(46)), reflecting variations in blood volume and oxyhemoglobin saturation, respectively. Following 50% MVC contractions, the mean postcontraction ΔSI(6) values were similar in the three groups. Following MVC only, and in the EDL muscle only, T2DM and obese participants had ∼56% lower ΔSI(6) than the lean individuals. Also following MVC only, the ΔSI(46) response in the EDL was lower in T2DM subjects than in lean individuals. These data suggest that skeletal muscle small vessel impairment occurs in T2DM and body mass index-matched subjects, in muscle-specific and contraction intensity-dependent manners.

  17. Postmaximal contraction blood volume responses are blunted in obese and type 2 diabetic subjects in a muscle-specific manner

    PubMed Central

    Sanchez, Otto A.; Copenhaver, Elizabeth A.; Chance, Marti A.; Fowler, Michael J.; Towse, Theodore F.; Kent-Braun, Jane A.

    2011-01-01

    The purpose of this study was to determine whether there are differences in postisometric contraction blood volume and oxygenation responses among groups of type 2 diabetes mellitus (T2DM), obese, and lean individuals detectable using MRI. Eight T2DM patients were individually matched by age, sex, and race to non-T2DM individuals with similar body mass index (obese) and lean subjects. Functional MRI was performed using a dual-gradient-recalled echo, echo-planar imaging sequence with a repetition time of 1 s and at two echo times (TE = 6 and 46 ms). Data were acquired before, during, and after 10-s isometric dorsiflexion contractions performed at 50 and 100% of maximal voluntary contraction (MVC) force. MRI signal intensity (SI) changes from the tibialis anterior and extensor digitorum longus muscles were plotted as functions of time for each TE. From each time course, the difference between the minimum and the maximum postcontraction SI (ΔSI) were determined for TE = 6 ms (ΔSI6) and TE = 46 ms (ΔSI46), reflecting variations in blood volume and oxyhemoglobin saturation, respectively. Following 50% MVC contractions, the mean postcontraction ΔSI6 values were similar in the three groups. Following MVC only, and in the EDL muscle only, T2DM and obese participants had ∼56% lower ΔSI6 than the lean individuals. Also following MVC only, the ΔSI46 response in the EDL was lower in T2DM subjects than in lean individuals. These data suggest that skeletal muscle small vessel impairment occurs in T2DM and body mass index-matched subjects, in muscle-specific and contraction intensity-dependent manners. PMID:21572006

  18. Randomized Noninferiority Trial of Reduced High-Dose Volume Versus Standard Volume Radiation Therapy for Muscle-Invasive Bladder Cancer: Results of the BC2001 Trial (CRUK/01/004)

    SciTech Connect

    Huddart, Robert A.; Hall, Emma; Hussain, Syed A.; Jenkins, Peter; Rawlings, Christine; Tremlett, Jean; Crundwell, Malcolm; Adab, Fawzi A.; Sheehan, Denise; Syndikus, Isabel; Hendron, Carey; Lewis, Rebecca; Waters, Rachel; James, Nicholas D.

    2013-10-01

    Purpose: To test whether reducing radiation dose to uninvolved bladder while maintaining dose to the tumor would reduce side effects without impairing local control in the treatment of muscle-invasive bladder cancer. Methods and Materials: In this phase III multicenter trial, 219 patients were randomized to standard whole-bladder radiation therapy (sRT) or reduced high-dose volume radiation therapy (RHDVRT) that aimed to deliver full radiation dose to the tumor and 80% of maximum dose to the uninvolved bladder. Participants were also randomly assigned to receive radiation therapy alone or radiation therapy plus chemotherapy in a partial 2 × 2 factorial design. The primary endpoints for the radiation therapy volume comparison were late toxicity and time to locoregional recurrence (with a noninferiority margin of 10% at 2 years). Results: Overall incidence of late toxicity was less than predicted, with a cumulative 2-year Radiation Therapy Oncology Group grade 3/4 toxicity rate of 13% (95% confidence interval 8%, 20%) and no statistically significant differences between groups. The difference in 2-year locoregional recurrence free rate (RHDVRT − sRT) was 6.4% (95% confidence interval −7.3%, 16.8%) under an intention to treat analysis and 2.6% (−12.8%, 14.6%) in the “per-protocol” population. Conclusions: In this study RHDVRT did not result in a statistically significant reduction in late side effects compared with sRT, and noninferiority of locoregional control could not be concluded formally. However, overall low rates of clinically significant toxicity combined with low rates of invasive bladder cancer relapse confirm that (chemo)radiation therapy is a valid option for the treatment of muscle-invasive bladder cancer.

  19. SUPPLEMENTARY COMPARISON: COOMET.RI(II)-S1.Rn-222 (169/UA/98): Rn-222 volume activity comparison

    NASA Astrophysics Data System (ADS)

    Skliarov, V.; Röttger, A.; Honig, A.; Korostin, S.; Kuznetsov, S.; Lapenas, A.; Milevsky, V.; Ivaniukovich, A.; Kharitonov, I.; Sepman, S.

    2009-01-01

    According to a first program, a supplementary comparison of Rn-222 volume activity was drawn up as a bilateral supplementary comparison between NSC 'Institute of Metrology', Ukraine, and VNIIFTRI, Russia. It took place in March 2005. In April 2005, at the 5th meeting of COOMET held in Braunschweig (Germany), representatives of these institutes exchanged data which showed the comparability of the national standards of Ukraine and Russia for the check points. During the discussion of the procedure some other institutes decided to join the comparison program, which was extended to BelGIM (Belarus), PTB (Germany), VNIIM (Russia) and RMTC (Latvia). The national standards of volume activity of radon-222 were thus calibrated using one standard radon radiometer as the transfer standard. Results are shown in the Final Report of the comparison. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by COOMET, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  20. Aging related changes in determinants of muscle force generating capacity: a comparison of muscle aging in men and male rodents.

    PubMed

    Ballak, Sam B; Degens, Hans; de Haan, Arnold; Jaspers, Richard T

    2014-03-01

    Human aging is associated with a progressive decline in skeletal muscle mass and force generating capacity, however the exact mechanisms underlying these changes are not fully understood. Rodents models have often been used to enhance our understanding of mechanisms of age-related changes in human skeletal muscle. However, to what extent age-related alterations in determinants of muscle force generating capacity observed in rodents resemble those in humans has not been considered thoroughly. This review compares the effect of aging on muscle force generating determinants (muscle mass, fiber size, fiber number, fiber type distribution and muscle specific tension), in men and male rodents at similar relative age. It appears that muscle aging in male F344*BN rat resembles that in men most; 32-35-month-old rats exhibit similar signs of muscle weakness to those of 70-80-yr-old men, and the decline in 36-38-month-old rats is similar to that in men aged over 80 yrs. For male C57BL/6 mice, age-related decline in muscle force generating capacity seems to occur only at higher relative age than in men. We conclude that the effects on determinants of muscle force differ between species as well as within species, but qualitatively show the same pattern as that observed in men.

  1. Botulinum toxin (Dysport) treatment of the spastic gastrocnemius muscle in children with cerebral palsy: a randomized trial comparing two injection volumes.

    PubMed

    Hu, Gwo-Chi; Chuang, Yao-Chia; Liu, Jen-Pei; Chien, Kuo-Liong; Chen, Yi-Min; Chen, Ying-Fang

    2009-01-01

    To compare the effect of equivalent doses in two different volumes of botulinum toxin type A (Dysport) on gastrocnemius spasticity. Single-blind, randomized, controlled trial. Hospital rehabilitation department. Twenty-two children with spastic diplegic or quadriplegic cerebral palsy. High (500 U/5 mL) and low (500 U/1 mL)-volume preparations of Dysport were injected into the gastrocnemius muscles, each child randomly receiving one preparation in the right and the other in the left leg. Dynamic ankle joint range of motion (ROM), passive ROM of the ankle joint, modified Ashworth Scale scores, and the areas of the compound muscle action potential assessed before treatment and at four and eight weeks post treatment. Both legs improved significantly. The mean (SD) improvements between baseline and the end of follow-up were 19.7 (10.83) degrees for dynamic ROM, 8.4 (9.19) degrees for passive ROM, -1.3 (0.6) for modified Ashworth Scale scores, and -9.4 (11.41) mV-ms for compound muscle action potential in the high-volume group; and 13.5 (10.45) degrees for dynamic ROM, 7.4 (7.88) for passive ROM, -0.9 (0.5) for modified Ashworth Scale scores, and -5.9 (7.50) mV-ms for areas of compound muscle action potential in the low-volume group. The high-volume preparation yielded significantly greater improvement in dynamic ROM (P<0.001), muscle tone (P < 0.001), and lower compound muscle action potential area (P = 0.006). A high-volume preparation of Dysport is more effective than a low volume in reducing spasticity in the gastrocnemius muscle.

  2. INTERLABORATORY COMPARISON OF A REDUCED VOLUME MARINE SEDIMENT TOXICITY TEST METHOD USING AMPHIPOD AMPELISCA ABDITA

    EPA Science Inventory

    The U.S. Environmental Protection Agency has standardized methods for performing acute marine amphipod sediment toxicity tests. A test design reducing sediment volume from 200 to 50 ml and overlying water from 600 to 150 ml was recently proposed. An interlaboratory comparison wa...

  3. Blanket comparison and selection study. Final report. Volume 3

    SciTech Connect

    Not Available

    1984-09-01

    The study focused on: (1) Development of reference design guidelines, evaluation criteria, and a methodology for evaluating and ranking candidate blanket concepts. (2) Compilation of the required data base and development of a uniform systems analysis for comparison. (3) Development of conceptual designs for the comparative evaluation. (4) Evaluation of leading concepts for engineering feasibility, economic performance, and safety. (5) Identification and prioritization of R and D requirements for the leading blanket concepts. Sixteen concepts (nine TMR and seven tokamak) which were identified as leading candidates in the early phases of the study, were evaluated in detail. The overall evaluation concluded that the following concepts should provide the focus for the blanket R and D program: (Breeder/Coolant/Structure), Lithium/Lithium/Vanadium Alloy, Li/sub 2/O/Helium/Ferritic Steel, LiPb Alloy/LiPb Alloy/Vanadium Alloy, and Lithium/Helium/Ferritic Steel. The primary R and D issues for the Li/Li/V concept are the development of an advanced structural alloy, resolution of MHD and corrosion problems, provision for an inert atmosphere (e.g., N/sub 2/) in the reactor building, and the development of non-water cooled near-plasma components, particularly for the tokamak. The main issues for the LiPb/LiPb/V concept are similar to the Li/Li/V blanket with the addition of resolving the tritium recovery issue. The R and D issues for Li/sub 2/O/He/FS concept include resolution of the tritium recovery/containment issue, achieving adequate tritium breeding and resolving other solid breeder issues such as swelling and fabrication concerns. Major concerns for the Li/He/FS concepts are related to its rather poor economic performance. Improvement of its economic performance will be somewhat concept-dependent and will be more of a systems engineering issue.

  4. Blanket comparison and selection study. Final report. Volume 2

    SciTech Connect

    Not Available

    1984-09-01

    The study focused on: (1) Development of reference design guidelines, evaluation criteria, and a methodology for evaluating and ranking candidate blanket concepts. (2) Compilation of the required data base and development of a uniform systems analysis for comparison. (3) Development of conceptual designs for the comparative evaluation. (4) Evaluation of leading concepts for engineering feasibility, economic performance, and safety. (5) Identification and prioritization of R and D requirements for the leading blanket concepts. Sixteen concepts (nine TMR and seven tokamak) which were identified as leading candidates in the early phases of the study, were evaluated in detail. The overall evaluation concluded that the following concepts should provide the focus for the blanket R and D program: (Breeder/Coolant/Structure), Lithium/Lithium/Vanadium Alloy, Li/sub 2/O/Helium/Ferritic Steel, LiPb Alloy/LiPb Alloy/Vanadium Alloy, and Lithium/Helium/Ferritic Steel. The primary R and D issues for the Li/Li/V concept are the development of an advanced structural alloy, resolution of MHD and corrosion problems, provision for an inert atmosphere (e.g., N/sub 2/) in the reactor building, and the development of non-water cooled near-plasma components, particularly for the tokamak. The main issues for the LiPb/LiPb/V concepts are similar to the Li/Li/V blanket with the addition of resolving the tritium recovery issue. The R and D issues for Li/sub 2/O/He/FS concept include resolution of the tritium recovery/containment issue, achieving adequate tritium breeding and resolving other solid breeder issues such as swelling and fabrication concerns. Major concerns for the Li/He/FS concept are related to its rather poor economic performance. Improvement of its economic performance will be somewhat concept-dependent and will be more of a systems engineering issue.

  5. Blanket comparison and selection study. Final report. Volume 1

    SciTech Connect

    Not Available

    1984-09-01

    The study focused on: (1) Development of reference design guidelines, evaluation criteria, and a methodology for evaluating and ranking candidate blanket concepts. (2) Compilation of the required data base and development of a uniform systems analysis for comparison. (3) Development of conceptual designs for the comparative evaluation. (4) Evaluation of leading concepts for engineering feasibility, economic performance, and safety. (5) Identification and prioritization of R and D requirements for the leading blanket concepts. Sixteen concepts (nine TMR and seven tokamak) which were identified as leading candidates in the early phases of the study, were evaluated in detail. The overall evaluation concluded that the following concepts should provide the focus for the blanket R and D program: (Breeder/Coolant/Structure), Lithium/Lithium/Vanadium Alloy, Li/sub 2/O/Helium/Ferritic Steel, LiPb Alloy/LiPb Alloy/Vanadium Alloy, and Lithium/Helium/Ferritic Steel. The primary R and D issues for the Li/Li/V concept are the development of an advanced structural alloy, resolution of MHD and corrosion problems, provision for an inert atmosphere (e.g., N/sub 2/) in the reactor building, and the development of non-water cooled near-plasma components, particularly for the tokamak. The main issues for the LiPb/LiPb/V concept are similar to the Li/Li/V blanket with the addition of resolving the tritium recovery issue. The R and D issues for Li/sub 2/O/He/FS concept include resolution of the tritium recovery/containment issue, achieving adequate tritium breeding and resolving other solid breeder issues such as swelling and fabrication concerns. Major concerns for the Li/He/FS concept are related to its rather poor economic performance. Improvement of its economic performance will be somewhat concept-dependent and will be more of a systems engineering issue.

  6. A comparison of the Acapella and a threshold inspiratory muscle trainer for sputum clearance in bronchiectasis-A pilot study.

    PubMed

    Naraparaju, Sushmitha; Vaishali, K; Venkatesan, Prem; Acharya, Vishak

    2010-08-01

    Inspiratory muscle training is used to specifically strengthen the respiratory muscles. Controversy exists regarding the use of inspiratory muscle training as a method of facilitating airways clearance. Acapella is already known to be effective in airway clearance. The objective of the study was to compare the effects of the Acapella and a threshold inspiratory muscle trainer as a method of airway clearance in subjects with bronchiectasis and to determine patient preference between the two techniques. Thirty patients (10 males, 20 females) mean age of 50.67+/-6.37 (mean+/-SD) with a history of expectoration of more than 30 ml sputum per day were recruited. The sequence of therapy was allocated by block randomization. Assessment and familiarization session was performed on day 1. Treatments employing the Acapella and inspiratory muscle trainer were done on days 2 and 3. Treatment order and allocation was determined by block randomization. Sputum volume was measured during and 2 hours after the treatment and patient treatment preference was recorded. A statistically significant difference was found in the sputum volume expectorated after treatment with the Acapella (7.16+/-1.12 ml) compared with the threshold inspiratory muscle trainer (6.46+/-1.08 ml). Patients preferred Acapella in terms of usefulness of clearing secretions. The present study demonstrated increased sputum clearance following the use of the Acapella when compared to the threshold inspiratory muscle trainer. In addition, the Acapella was preferred by patients who judged that it was more useful in clearing secretions.

  7. Lanreotide Reduces Liver Volume, But Might Not Improve Muscle Wasting or Weight Loss, in Patients With Symptomatic Polycystic Liver Disease.

    PubMed

    Temmerman, Frederik; Ho, Thien Ahn; Vanslembrouck, Ragna; Coudyzer, Walter; Billen, Jaak; Dobbels, Fabienne; van Pelt, Jos; Bammens, Bert; Pirson, Yves; Nevens, Frederik

    2015-12-01

    Polycystic liver disease (PCLD) can induce malnutrition owing to extensive hepatomegaly and patients might require liver transplantation. Six months of treatment with the somatostatin analogue lanreotide (120 mg) reduces liver volume. We investigated the efficacy of a lower dose of lanreotide and its effects on nutritional status. We performed an 18-month prospective study at 2 tertiary medical centers in Belgium from January 2011 through August 2012. Fifty-nine patients with symptomatic PCLD were given lanreotide (90 mg, every 4 weeks) for 6 months. Patients with reductions in liver volume of more than 100 mL (responders, primary end point) continued to receive lanreotide (90 mg) for an additional year (18 months total). Nonresponders were offered increased doses, up to 120 mg lanreotide, until 18 months. Liver volume and body composition were measured by computed tomography at baseline and at months 6 and 18. Patients also were assessed by the PCLD-specific complaint assessment at these time points. Fifty-three patients completed the study; 21 patients (40%) were responders. Nineteen of the responders (90%) continued as responders until 18 months. At this time point, they had a mean reduction in absolute liver volume of 430 ± 92 mL. In nonresponders (n = 32), liver volume increased by a mean volume of 120 ± 42 mL at 6 months. However, no further increase was observed after dose escalation in the 24 patients who continued to the 18-month end point. All subjects had decreased scores on all subscales of the PCLD-specific complaint assessment, including better food intake (P = .04). Subjects did not have a mean change in subcutaneous or visceral fat mass, but did have decreases in mean body weight (2 kg) and total muscle mass (1.06 cm(2)/h(2)). Subjects also had a significant mean reduction in their level of insulin-like growth factor 1, from 19% below the age-adjusted normal range level at baseline to 50% at 18 months (P = .002). In a prospective study, we

  8. Fat quantification in skeletal muscle using multigradient-echo imaging: Comparison of fat and water references.

    PubMed

    Peterson, Pernilla; Romu, Thobias; Brorson, Håkan; Dahlqvist Leinhard, Olof; Månsson, Sven

    2016-01-01

    To investigate the precision, accuracy, and repeatability of water/fat imaging-based fat quantification in muscle tissue using a large flip angle (FA) and a fat reference for the calculation of the proton density fat fraction (FF). Comparison is made to a small FA water reference approach. An Intralipid phantom and both forearms of six patients suffering from lymphedema and 10 healthy volunteers were investigated at 1.5T. Two multigradient-echo sequences with eight echo times and FAs of 10° and 85° were acquired. For healthy volunteers, the acquisition of the right arm was performed twice with repositioning. From each set, water reference FF and fat reference FF images were reconstructed and the average FF and the standard deviation were calculated within the subfascial compartment. The small FA water reference was considered the reference standard. A high agreement was found between the small FA water reference and large FA fat reference methods (FF bias = 0.31%). In this study, the large FA fat reference approach also resulted in higher precision (38% smaller FF standard deviation in homogenous muscle tissue), but no significant difference in repeatability between the various methods was detected (coefficient of repeatability of small FA water reference approach 0.41%). The precision of fat quantification in muscle tissue can be increased with maintained accuracy using a larger flip angle, if a fat reference instead of a water reference is used. © 2015 Wiley Periodicals, Inc.

  9. [Comparison of volume preset and pressure preset ventilators during daytime nasal ventilation in chronic respiratory failure].

    PubMed

    Perrin, C; Wolter, P; Berthier, F; Tamisier, R; Jullien, V; Lemoigne, F; Blaive, B

    2001-02-01

    Both volume preset and pressure preset ventilators are available for domiciliary nasal ventilation. Owing to their technical characteristics, it has been suggested that impaired ventilatory mechanics might cause a drop in the tidal volume (Vt) delivered by pressure preset devices, thereby placing mechanical ventilation at risk of inefficacy. We have assessed two ventilator systems (one pressure preset and one volume preset) with regard to the tidal volume and end-tidal carbon dioxide tension (PetCO(2)) changes that may be achieved in a group of awake patients with stable chronic respiratory failure (CRF). Eleven patients with stable CRF were ventilated in the assist/control mode for two consecutive one-hour periods. One ventilator was tested each hour, in random order. The VIGIL'AIR(R) system was used to record Vt, Respiratory Rate (RR), and Inspiratory/Expiratory ratio (I/E). The deviation E (E=preset value - measured value) was calculated for each measurement. Changes in PetCO(2) and arterial oxygen saturation were determined respectively by a capnometer and a pulse oximeter. Comparison of the mean deviation of Vt calculated for the two ventilators revealed a difference in patients with chronic obstructive pulmonary disease (COPD). The deviation was greatest with the pressure preset ventilator (PPV), which gave mean measured values higher than the mean preset values. The same comparison failed to reveal any difference in restrictive CRF. Comparison of the volume preset and pressure preset ventilators for RR, I/E and PetCO(2) did not reveal any difference. Compared to the volume preset ventilator, the efficacy of PPV to ventilate is not affected by the restrictive or obstructive nature of CRF. Our results show that pressure-preset ventilator is an adequate alternative to the volume-preset device for daytime non invasive ventilation in chronic respiratory insufficiency.

  10. Quantitative and qualitative MR-imaging assessment of vastus medialis muscle volume loss in asymptomatic patients after anterior cruciate ligament reconstruction.

    PubMed

    Marcon, Magda; Ciritsis, Bernhard; Laux, Christoph; Nanz, Daniel; Fischer, Michael A; Andreisek, Gustav; Ulbrich, Erika J

    2015-08-01

    To quantitatively and qualitatively assess vastus medialis muscle atrophy in asymptomatic patients with anterior cruciate ligament reconstruction, using the nonoperated leg as control. Prospective Institutional Review Board approved study with written informed patient consent. Thirty-three asymptomatic patients (men, 21; women,12) with ACL-reconstruction underwent MR imaging of both legs (axial T1-weighted spin-echo and 3D spoiled dual gradient-echo sequences). Muscle volume and average fat-signal fraction (FSF) of the vastus medialis muscles were measured. Additionally, Goutallier classification was used to classify fatty muscle degeneration. Significant side differences were evaluated using the Wilcoxon test and, between volumes and FSF, using student t-tests with P-value < 0.05 and < 0.025, respectively. The muscle volume was significantly smaller in the operated (mean ± SD, 430.6 ± 119.6 cm(3) ; range, 197.3 to 641.7 cm(3) ) than in the nonoperated leg (479.5 ± 124.8 cm(3) ; 261.4 to 658.9 cm(3) ) (P < 0.001). Corresponding FSF was 6.3 ± 1.5% (3.9 to 9.2%) and 5.8 ± 0.9% (4.0 to 7.4%), respectively, with a nonsignificant (P > 0.025) difference. The relative muscle-volume and FSF differences were -10.1 ± 8.6% (7.1 to -30.1%) and 10.9 ± 29.4% (39.7 to 40.1%). The qualitative assessment revealed no significant differences (P > 0.1). A significant muscle volume loss of the vastus medialis muscle does exist in asymptomatic patients with ACL-reconstruction, but without fatty degeneration. © 2014 Wiley Periodicals, Inc.

  11. Final report on key comparison CCQM-K81: Chloramphenicol in pig muscle

    NASA Astrophysics Data System (ADS)

    Polzer, Joachim; Henrion, Andre; Gowik, Petra

    2013-01-01

    Under the auspices of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) a key comparison, CCQM-K81 'Chloramphenicol in pig muscle', was coordinated by BVL and PTB in 2009/2010. Six NMIs/DIs participated in this comparison. Chloramphenicol (CAP) is an effective broad-spectrum antibiotic which can in principle be used for the treatment of humans and animals. Its use for the treatment of food-producing animals is, however, forbidden worldwide in many countries due to potential severe side effects. The key comparison was the follow-up to the successful pilot study 'CCQM-P90: chloramphenicol in milk'. With this key comparison it was intended to demonstrate the capability of NMIs/DIs to analyse traces of CAP in food at concentration levels resulting from legal requirements for food control. Additionally, the quality of this kind of analysis with respect to compliance with legal requirements for food control methods and the international comparability of measurements should be evaluated in general. The study was classified as a 'track C' study (studies in emerging areas of global interest). For the study incurred lyophilised pig muscle material containing CAP (at a mass-fraction level around the maximum allowable level for import for a number of countries) has been produced as a candidate reference material by BVL and IRMM (Institute for Reference Materials and Measurements, JRC of the European Commission). Animal treatment and slaughtering of the animal to gain incurred muscle material as well as pre-testing of the CAP content was done at the BVL. The IRMM did further processing of the material and testing of homogeneity and stability. Participants were invited to assign the mass fraction of free CAP in the comparison sample. CCQM-K81 demonstrated successfully the capability of the participating laboratories to assign chloramphenicol values in tissue down to residue levels of around 0.3 ng/g (referring to the

  12. Development of congenital clubfoot during growth: a long-term study on the basis of pedobarography, biomechanics, and magnetic resonance imaging measurements of muscle volumes.

    PubMed

    Lampe, Renée; Mitternacht, Jürgen; von Pfister, Lorenz; Turova, Varvara; Blumenstein, Tobias; Alves-Pinto, Ana

    2017-03-01

    The aim of this study was to clarify the degree to which the operated congenital asymptomatic clubfoot still shows malpositions or whether it approaches a physiological development with increasing age. Clubfeet of 12 children were examined repeatedly over up to 10 years using pedobarography. The muscle volumes of the lower legs were investigated with MRI and compared with those of a healthy control group. Although some characteristics of clubfoot remained in the plantar pressure distribution, a gradual decrease in the heel and metatarsus load accompanied by an increase in the forefoot load could be registered as is typical for a developing healthy child's foot. The MRI showed a reduced volume of all muscles of the affected lower leg. A correlation was detected between the measured moments in the upper and lower ankle joints and the volumes of the muscles that move these joints. Even though a functional and anatomical separation between the two groups existed, the general developmental changes during growth were similar. The combination of pedobarographic data and derived joint moments with MRI-measured muscle volumes indicated that higher ankle joint moments in clubfoot were associated with smaller muscle volume and were therefore generated by higher joint rigidity.

  13. Dose-response relationship between weekly resistance training volume and increases in muscle mass: A systematic review and meta-analysis.

    PubMed

    Schoenfeld, Brad J; Ogborn, Dan; Krieger, James W

    2017-06-01

    The purpose of this paper was to systematically review the current literature and elucidate the effects of total weekly resistance training (RT) volume on changes in measures of muscle mass via meta-regression. The final analysis comprised 34 treatment groups from 15 studies. Outcomes for weekly sets as a continuous variable showed a significant effect of volume on changes in muscle size (P = 0.002). Each additional set was associated with an increase in effect size (ES) of 0.023 corresponding to an increase in the percentage gain by 0.37%. Outcomes for weekly sets categorised as lower or higher within each study showed a significant effect of volume on changes in muscle size (P = 0.03); the ES difference between higher and lower volumes was 0.241, which equated to a percentage gain difference of 3.9%. Outcomes for weekly sets as a three-level categorical variable (<5, 5-9 and 10+ per muscle) showed a trend for an effect of weekly sets (P = 0.074). The findings indicate a graded dose-response relationship whereby increases in RT volume produce greater gains in muscle hypertrophy.

  14. Comparison of Muscle BOLD Responses to Arterial Occlusion at 3T and 7T

    PubMed Central

    Towse, Theodore F.; Childs, Benjamin T.; Sabin, Shea A.; Bush, Emily C.; Elder, Christopher P.; Damon, Bruce M.

    2014-01-01

    Purpose The purpose of this study was to determine the feasibility of muscle BOLD (mBOLD) imaging at 7T by comparing the changes in R2* of muscle at 3 and 7T in response to a brief period of tourniquet-induced ischemia. Methods Eight subjects (3 male), aged 29.5 ± 6.1 years (mean ± standard deviation, SD), 167.0 ± 10.6 cm tall with a body mass of 62.0 ± 18.0 kg, participated in the study. Subjects reported to the lab on four separate occasions including a habituation session, two MRI scans, and in a subset of subjects, a session during which changes in blood flow and blood oxygenation were quantified using Doppler ultrasound (U/S) and near-infrared spectroscopy (NIRS) respectively. For statistical comparisons between 3T and 7T, R2* rate constants were calculated as R2* = 1/T2*. Results The mean pre-occlusion R2* value was greater at 7T than at 3T (60.16 ± 2.95 vs 35.17 ± 0.35 s−1 respectively, p <0.001). Also, the mean ΔR2*END and ΔR2*POST values were greater for 7T than for 3T (−2.36 ± 0.25 vs. −1.24 ± 0.39 s−1, respectively, Table 1). Conclusion Muscle BOLD contrast at 7T is as much as six-fold greater than at 3T. In addition to providing greater SNR and CNR, 7T mBOLD studies may offer further advantages in the form of greater sensitivity to pathological changes in the muscle microcirculation. PMID:25884888

  15. Hindlimb muscle fiber types in two frogs (Rana catesbeiana and Litoria caerulea) with different locomotor behaviors: histochemical and enzymatic comparison.

    PubMed

    Crockett, Christy J; Peters, Susan E

    2008-03-01

    To test how differences in locomotor behaviors may be reflected in muscle fiber-type diversity within anurans, a comparison of hindlimb muscles between the powerful terrestrial hopper, Rana catesbeiana, and the tree frog, Litoria caerulea, was done. One postural muscle (tibialis posticus, TP) and one primary hopping muscle (plantaris longus, PL), were characterized to identify muscle fiber types using standard histochemical methods. In addition, spectophotometric analysis of activity levels of the oxidative enzyme citrate synthase (CS) and the glycolytic enzyme lactate dehydrogenase (LDH) were done in each muscle. In spite of presumed differences in behavior between the species, we found no significant differences in the proportions of the identified fiber types when the muscles were compared across species. In addition, there were no significant differences in the proportions of the different fiber types between the postural versus phasic muscles within species. Within Rana, the postural muscle (TP) had greater oxidative capacity (as measured by CS activity) than did the phasic muscle (PL). Both muscles had equivalent LDH activities. Within Litoria, PL and TP did not differ in either LDH or CS activities. Both PL and TP of Litoria had less LDH activity and greater CS activity than their homologs in Rana. Thus, in spite of the uniform populations of fiber types between muscles and species, the metabolic diversity based on enzyme activity is consistent with behavioral differences between the species. These results suggest that the range of functional diversity within fiber types may be very broad in anurans, and histochemical fiber typing alone is not a clear indicator of their metabolic or functional properties.

  16. Triphasic multinutrient supplementation during acute resistance exercise improves session volume load and reduces muscle damage in strength-trained athletes.

    PubMed

    Bird, Stephen P; Mabon, Tom; Pryde, Mitchell; Feebrey, Sarah; Cannon, Jack

    2013-05-01

    We hypothesized that triphasic multinutrient supplementation during acute resistance exercise would enhance muscular performance, produce a more favorable anabolic profile, and reduce biochemical markers of muscle damage in strength-trained athletes. Fifteen male strength-trained athletes completed two acute lower-body resistance exercise sessions to fatigue 7 days apart. After a 4-hour fast, participants consumed either a multinutrient supplement (Musashi 1-2-3 Step System, Notting Hill, Australia) (SUPP) or placebo (PLA) beverage preexercise (PRE), during (DUR), and immediately postexercise (IP). Session volume loads were calculated as kilograms × repetitions. Lower-body peak power was measured using unloaded repeated countermovement jumps, and blood samples were collected to assess biochemistry, serum hormones, and muscle damage markers at PRE, DUR, IP, 30 minutes postexercise (P30), and 24 hours postexercise (P24h). The SUPP demonstrated increased glucose concentrations at DUR and IP compared with at PRE (P < .01), whereas PLA demonstrated higher glucose at P30 compared with at PRE (P < .001). Session volume load was higher for SUPP compared with PLA (P < .05). Cortisol increased at DUR, IP, and P30 compared with at PRE in both treatments (P < .05); however, SUPP also displayed lower cortisol at P24h compared with at PRE and PLA (P < .01). The total testosterone response to exercise was higher for PLA compared with SUPP (P < .01); however, total creatine kinase and C-reactive protein responses to exercise were lower for SUPP compared with PLA (P < .05). These data indicate that although triphasic multinutrient supplementation did not produce a more favorable anabolic profile, it improved acute resistance exercise performance while attenuating muscle damage in strength-trained athletes.

  17. Conditions that maximize floodplain downed wood volumes: a comparison across three biomes

    NASA Astrophysics Data System (ADS)

    Lininger, K.; Wohl, E.; Rose, J. R.; Sutfin, N. A.

    2015-12-01

    Floodplain downed wood can provide important habitat for aquatic, riparian, and terrestrial organisms. This wood, which can function as both a storage area and source for large wood in river channels, can also be a significant organic carbon stock in river-floodplain ecosystems. We present data on downed wood volumes for different floodplain vegetation communities in the central Yukon River Basin in interior Alaska. We measured downed wood volume per unit floodplain area and wood decay characteristics within four distinct floodplain vegetation communities, and equate downed wood volumes per unit area to total organic carbon per unit area. Preliminary results suggest that downed wood volumes are greatest in disturbed white spruce forests, compared to undisturbed white spruce, deciduous forests, and black spruce woody wetlands. Disturbances contributing to large wood volumes include fire, wind, and ice jam floods. We also compare wood volumes in interior Alaska to downed wood volumes in other unmanaged floodplain vegetation communities, including a subtropical lowland alluvial river-floodplain and a semi-arid mountainous river-floodplain. These three datasets provide comparisons of unmanaged riparian forests across diverse climatic settings and highlight the climatic conditions and biomes that result in substantial downed wood and organic carbon storage in floodplain environments.

  18. Intensive training and reduced volume increases muscle FXYD1 expression and phosphorylation at rest and during exercise in athletes

    PubMed Central

    Thomassen, Martin; Gunnarsson, Thomas P.; Christensen, Peter M.; Pavlovic, Davor; Shattock, Michael J.

    2016-01-01

    The present study examined the effect of intensive training in combination with marked reduction in training volume on phospholemman (FXYD1) expression and phosphorylation at rest and during exercise. Eight well-trained cyclists replaced their regular training with speed-endurance training (10–12 × ∼30-s sprints) two or three times per week and aerobic high-intensity training (4–5 × 3–4 min at 90–95% of peak aerobic power output) 1–2 times per week for 7 wk and reduced the training volume by 70%. Muscle biopsies were obtained before and during a repeated high-intensity exercise protocol, and protein expression and phosphorylation were determined by Western blot analysis. Expression of FXYD1 (30%), actin (40%), mammalian target of rapamycin (mTOR) (12%), phospholamban (PLN) (16%), and Ca2+/calmodulin-dependent protein kinase II (CaMKII) γ/δ (25%) was higher (P < 0.05) than before the training intervention. In addition, after the intervention, nonspecific FXYD1 phosphorylation was higher (P < 0.05) at rest and during exercise, mainly achieved by an increased FXYD1 Ser-68 phosphorylation, compared with before the intervention. CaMKII, Thr-287, and eukaryotic elongation factor 2 Thr-56 phosphorylation at rest and during exercise, overall PKCα/β, Thr-638/641, and mTOR Ser-2448 phosphorylation during repeated intense exercise as well as resting PLN Thr-17 phosphorylation were also higher (P < 0.05) compared with before the intervention period. Thus, a period of high-intensity training with reduced training volume increases expression and phosphorylation levels of FXYD1, which may affect Na+/K+ pump activity and muscle K+ homeostasis during intense exercise. Furthermore, higher expression of CaMKII and PLN, as well as increased phosphorylation of CaMKII Thr-287 may have improved intracellular Ca2+ handling. PMID:26791827

  19. Intensive training and reduced volume increases muscle FXYD1 expression and phosphorylation at rest and during exercise in athletes.

    PubMed

    Thomassen, Martin; Gunnarsson, Thomas P; Christensen, Peter M; Pavlovic, Davor; Shattock, Michael J; Bangsbo, Jens

    2016-04-01

    The present study examined the effect of intensive training in combination with marked reduction in training volume on phospholemman (FXYD1) expression and phosphorylation at rest and during exercise. Eight well-trained cyclists replaced their regular training with speed-endurance training (10-12 × ∼30-s sprints) two or three times per week and aerobic high-intensity training (4-5 × 3-4 min at 90-95% of peak aerobic power output) 1-2 times per week for 7 wk and reduced the training volume by 70%. Muscle biopsies were obtained before and during a repeated high-intensity exercise protocol, and protein expression and phosphorylation were determined by Western blot analysis. Expression of FXYD1 (30%), actin (40%), mammalian target of rapamycin (mTOR) (12%), phospholamban (PLN) (16%), and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) γ/δ (25%) was higher (P < 0.05) than before the training intervention. In addition, after the intervention, nonspecific FXYD1 phosphorylation was higher (P < 0.05) at rest and during exercise, mainly achieved by an increased FXYD1 Ser-68 phosphorylation, compared with before the intervention. CaMKII, Thr-287, and eukaryotic elongation factor 2 Thr-56 phosphorylation at rest and during exercise, overall PKCα/β, Thr-638/641, and mTOR Ser-2448 phosphorylation during repeated intense exercise as well as resting PLN Thr-17 phosphorylation were also higher (P < 0.05) compared with before the intervention period. Thus, a period of high-intensity training with reduced training volume increases expression and phosphorylation levels of FXYD1, which may affect Na(+)/K(+) pump activity and muscle K(+) homeostasis during intense exercise. Furthermore, higher expression of CaMKII and PLN, as well as increased phosphorylation of CaMKII Thr-287 may have improved intracellular Ca(2+) handling.

  20. Comparison of pulmonary function and back muscle strength according to the degree of spinal curvature of healthy adults

    PubMed Central

    You, Jae Eung; Lee, Hye Young; Kim, Kyoung

    2015-01-01

    [Purpose] Degree of curvature on the spine is known to affect respiratory function and back muscle activation. We compared pulmonary function and back muscle strength according to the degree of curvature of the spine of healthy adults. [Subjects and Methods] Twenty-three healthy volunteers were enrolled. They were divided into two groups according to the degree of curvature of the spine: the below 2° group, and the above 2° group. The degree of curvature was assessed using the Adams forward bending test and a scoliometer. A pulmonary function test (PFT) was conducted, and back muscle strength was measured. [Results] No significant differences in PFT were found between the below 2° group and the above 2° group, in terms of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC), or peak expiratory flow (PEF). However, back muscle strength in the below 2 group was significantly higher than that of the above 2 group. [Conclusion] Our findings indicate that the degree of curvature of the spine is associated with back muscle strength in subjects who have spinal curvature within the normal range. Therefore, evaluation and treatment of back muscle strength might be helpful for preventing the progress of curvature of the spine in adolescents with potential scoliosis. PMID:26180321

  1. Comparison of pulmonary function and back muscle strength according to the degree of spinal curvature of healthy adults.

    PubMed

    You, Jae Eung; Lee, Hye Young; Kim, Kyoung

    2015-06-01

    [Purpose] Degree of curvature on the spine is known to affect respiratory function and back muscle activation. We compared pulmonary function and back muscle strength according to the degree of curvature of the spine of healthy adults. [Subjects and Methods] Twenty-three healthy volunteers were enrolled. They were divided into two groups according to the degree of curvature of the spine: the below 2° group, and the above 2° group. The degree of curvature was assessed using the Adams forward bending test and a scoliometer. A pulmonary function test (PFT) was conducted, and back muscle strength was measured. [Results] No significant differences in PFT were found between the below 2° group and the above 2° group, in terms of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC), or peak expiratory flow (PEF). However, back muscle strength in the below 2 group was significantly higher than that of the above 2 group. [Conclusion] Our findings indicate that the degree of curvature of the spine is associated with back muscle strength in subjects who have spinal curvature within the normal range. Therefore, evaluation and treatment of back muscle strength might be helpful for preventing the progress of curvature of the spine in adolescents with potential scoliosis.

  2. A comparison of wrist isokinetic muscle strength in wheelchair table tennis and wheelchair basketball players

    PubMed Central

    Akınoğlu, Bihter; Kocahan, Tuğba; Yıldırım, Necmiye Ün; Soylu, Çağlar; Apur, Ufuk; Hasanoğlu, Adnan

    2017-01-01

    Aim: The aim of this study was to compare isokinetic muscle strength of wrist flexor and extensor muscles in paralympic athletes. Methods: This study was carried out with the participation of 9 (4 females and 5 males) wheelchair (WC) table tennis players aged 24+3 and 8 male WC basketball players aged 26+3, met the criteria and voluntarly participate in the study. Body weight, height, body mass index and dominant extremity of the study subjects were recorded. İsokinetic measurement were performed with Isomed 2000® device. İsokinetic testing protocol; before the test all players performed the wrist flexion and extension isokinetic test with the 5 repeating at 90º/sec as a warm-up and comprehending the test. Then, wrist flexion and extension concentric-concentric strength measurements were performed with the 5 repeating at 60º/sec and with the 15 repeating at 240º/sec with the angle between 50 degrees of wrist flexion and 60 degrees of wrist extension and peak torque, peak torque/kg values and flexion/extension ratios were recorded. Mann-Whitney U test was used to compare isokinetic muscle strength quantitative variables in athletes. Findings: Isokinetic muscle strength of wrist flexors and extensors was higher in both sides in WC table tennis players with 60º/sec speed (p<0,05). İsokinetic muscle strength of wrist flexors and extensors was higher in both sides in WC basketball players with 240º/sec speed (p<0,05). There was no significant difference statistically between the groups in isokinetic wrist flexion and extansion peak torque/kg ratio in all speeds (p>0,05). Wrist flexion/extension peak torque ratios were similar in both groups. When examining the athletes flexion/extension ratios, wrist extensor muscles were weaker than flexor muscles and flexor muscles were average twice stronger than extensor muscles in both sports (Table1). Table 1. Comparison of wrist flexion and extension isokinetic muscle strength, peak torque/kg and agonist/antagonist ratio

  3. Comparison of trunk muscle forces and spinal loads estimated by two biomechanical models.

    PubMed

    Arjmand, N; Gagnon, D; Plamondon, A; Shirazi-Adl, A; Larivière, C

    2009-08-01

    Comparative studies between single-joint electromyography (EMG)- and optimization-driven models of the human spine in estimating trunk muscle and spinal compression forces have not been conclusive. Due to associated implications in ergonomic applications as well as prevention and treatment managements of low-back disorders, there is a need to critically compare existing single- and multi-joint spine models. A comprehensive comparison of muscle forces and spinal loads estimated by a single-joint (L5-S1 or L4-L5) EMG-driven model (EMGAO) and a multi-joint (T1-S1) Kinematics-driven finite element model (KD) of the spine under different static lifting activities in upright standing posture is carried out. Identical geometry for the spine and trunk musculature as well as passive properties are used in both models. Required model inputs including kinematics, force plate and surface EMG data are collected from one asymptomatic male subject. Contrary to somewhat similar external moments (with differences <11 Nm) as well as comparable compression forces at the L4-S1 joints (<20% except in the heaviest task with 52% difference) and sum of all trunk muscle forces (<26% except in the heaviest task with 44% difference), both models recruited trunk global and local lumbar muscles in markedly different proportions (ratio of total global over total local muscle forces in cases with load in hands remained >2.4 in the KD model whereas <1.0 in the EMGAO model) which in turn led to significantly different shear force estimates. Results of the EMGAO model were level dependent. Estimated L4-L5 intradiscal pressures were comparable to the measured data except for the heaviest task in which case the EMGAO model overestimated the measured pressure by 67%. Differences in predictions between these modeling approaches vary depending on the task simulated and the joint considered in the single-joint models of the spine. Such studies are essential to critically evaluate relative performance of

  4. Measurement of the trapezius muscle volume: A new assessment strategy of shoulder dysfunction after neck dissection for the treatment of head and neck cancers.

    PubMed

    Cho, Jae-Gu; Lee, Naree; Park, Min-Woo; Baek, Seung-Kuk; Kwon, Soon-Young; Jung, Kwang-Yoon; Woo, Jeong-Soo

    2015-05-01

    The purpose of this study was to determine the actual degree of shoulder muscle change and its relation to symptoms after neck dissection for head and neck cancers. Forty-two patients who underwent unilateral neck dissection were selected. Data obtained from each subject were trapezius muscle volume ratio and a Shoulder Disability Questionnaire (SDQ) score. Patients who had undergone neck dissection with spinal accessory nerve (SAN) preservation were compared with those who had received radical neck dissection. The preservation group was further separated into subgroups by the extent of neck dissection. Trapezius muscle volume ratio was higher and SDQ score was significantly lower in the SAN preservation group compared to the radical neck dissection group. However, the SAN preservation subgroups did not differ from each other. In addition, a good correlation between the muscle volume ratio and SDQ score was observed. With trapezius muscle volume ratio, clinicians may be able to diagnose shoulder dysfunction after neck dissection. Further research on the subject is warranted. This suggests a novel strategy for assessing the degree of shoulder dysfunction. © 2014 Wiley Periodicals, Inc.

  5. The difference in passive tension applied to the muscles composing the hamstrings - Comparison among muscles using ultrasound shear wave elastography.

    PubMed

    Nakamura, Masatoshi; Hasegawa, Satoshi; Umegaki, Hiroki; Nishishita, Satoru; Kobayashi, Takuya; Fujita, Kosuke; Tanaka, Hiroki; Ibuki, Satoko; Ichihashi, Noriaki

    2016-08-01

    Hamstring muscle strain is one of the most common injuries in sports. Therefore, to investigate the factors influencing hamstring strain, the differences in passive tension applied to the hamstring muscles at the same knee and hip positions as during terminal swing phase would be useful information. In addition, passive tension applied to the hamstrings could change with anterior or posterior tilt of the pelvis. The aims of this study were to investigate the difference in passive tension applied to the individual muscles composing the hamstrings during passive elongation, and to investigate the effect of pelvic position on passive tension. Fifteen healthy men volunteered for this study. The subject lay supine with the angle of the trunk axis to the femur of their dominant leg at 70° and the knee angle of the dominant leg fixed at 30° flexion. In three pelvic positions ("Non-Tilt", "Anterior-Tilt" and "Posterior-Tilt"), the shear elastic modulus of each muscle composing the hamstrings (semitendinosus, semimembranosus, and biceps femoris) was measured using an ultrasound shear wave elastography. The shear elastic modulus of semimembranosus was significantly higher than the others. Shear elastic modulus of the hamstrings in Anterior-Tilt was significantly higher than in Posterior-Tilt. Passive tension applied to semimembranosus is higher than the other muscles when the hamstring muscle is passively elongated, and passive tension applied to the hamstrings increases with anterior tilt of the pelvis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Amygdalar and hippocampal volume: A comparison between manual segmentation, Freesurfer and VBM.

    PubMed

    Grimm, Oliver; Pohlack, Sebastian; Cacciaglia, Raffaele; Winkelmann, Tobias; Plichta, Michael M; Demirakca, Traute; Flor, Herta

    2015-09-30

    Automated segmentation of the amygdala and the hippocampus is of interest for research looking at large datasets where manual segmentation of T1-weighted magnetic resonance tomography images is less feasible for morphometric analysis. Manual segmentation still remains the gold standard for subcortical structures like the hippocampus and the amygdala. A direct comparison of VBM8 and Freesurfer is rarely done, because VBM8 results are most often used for voxel-based analysis. We used the same region-of-interest (ROI) for Freesurfer and VBM8 to relate automated and manually derived volumes of the amygdala and the hippocampus. We processed a large manually segmented dataset of n=92 independent samples with an automated segmentation strategy (VBM8 vs. Freesurfer Version 5.0). For statistical analysis, we only calculated Pearsons's correlation coefficients, but used methods developed for comparison such as Lin's concordance coefficient. The correlation between automatic and manual segmentation was high for the hippocampus [0.58-0.76] and lower for the amygdala [0.45-0.59]. However, concordance coefficients point to higher concordance for the amygdala [0.46-0.62] instead of the hippocampus [0.06-0.12]. VBM8 and Freesurfer segmentation performed on a comparable level in comparison to manual segmentation. We conclude (1) that correlation alone does not capture systematic differences (e.g. of hippocampal volumes), (2) calculation of ROI volumes with VBM8 gives measurements comparable to Freesurfer V5.0 when using the same ROI and (3) systematic and proportional differences are caused mainly by different definitions of anatomic boundaries and only to a lesser part by different segmentation strategies. This work underscores the importance of using method comparison techniques and demonstrates that even with high correlation coefficients, there can be still large differences in absolute volume.

  7. Reconstructing muscle activation during normal walking: a comparison of symbolic and connectionist machine learning techniques.

    PubMed

    Heller, B W; Veltink, P H; Rijkhoff, N J; Rutten, W L; Andrews, B J

    1993-01-01

    One symbolic (rule-based inductive learning) and one connectionist (neural network) machine learning technique were used to reconstruct muscle activation patterns from kinematic data measured during normal human walking at several speeds. The activation patterns (or desired outputs) consisted of surface electromyographic (EMG) signals from the semitendinosus and vastus medialis muscles. The inputs consisted of flexion and extension angles measured at the hip and knee of the ipsilateral leg, their first and second derivatives, and bilateral foot contact information. The training set consisted of data from six trials, at two different speeds. The testing set consisted of data from two additional trials (one at each speed), which were not in the training set. It was possible to reconstruct the muscular activation at both speeds using both techniques. Timing of the reconstructed signals was accurate. The integrated value of the activation bursts was less accurate. The neural network gave a continuous output, whereas the rule-based inductive learning rule tree gave a quantised activation level. The advantage of rule-based inductive learning was that the rules used were both explicit and comprehensible, whilst the rules used by the neural network were implicit within its structure and not easily comprehended. The neural network was able to reconstruct the activation patterns of both muscles from one network, whereas two separate rule sets were needed for the rule-based technique. It is concluded that machine learning techniques, in comparison to explicit inverse muscular skeletal models, show good promise in modelling nearly cyclic movements such as locomotion at varying walking speeds.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Comparison of total protein concentration in skeletal muscle as measured by the Bradford and Lowry assays.

    PubMed

    Seevaratnam, Rajini; Patel, Barkha P; Hamadeh, Mazen J

    2009-06-01

    The Lowry and Bradford assays are the most commonly used methods of total protein quantification, yet vary in several aspects. To date, no comparisons have been made in skeletal muscle. We compared total protein concentrations of mouse red and white gastrocnemius, reagent stability, protein stability and range of linearity using both assays. The Lowry averaged protein concentrations 15% higher than the Bradford with a moderate correlation (r = 0.36, P = 0.01). However, Bland-Altman analysis revealed considerable bias (15.8 +/- 29.7%). Both Lowry reagents and its protein-reagent interactions were less stable over time than the Bradford. The linear range of concentration was smaller for the Lowry (0.05-0.50 mg/ml) than the Bradford (0-2.0 mg/ml). We conclude that the Bradford and Lowry measures of total protein concentration in skeletal muscle are not interchangeable. The Bradford and Lowry assays have various strengths and weaknesses in terms of substance interference and protein size. However, the Bradford provides greater reagent stability, protein-reagent stability and range of linearity, and requires less time to analyse compared to the Lowry assay.

  9. Rhythm and amplitude of rhythmic masticatory muscle activity during sleep in bruxers - comparison with gum chewing.

    PubMed

    Matsuda, Shinpei; Yamaguchi, Taihiko; Mikami, Saki; Okada, Kazuki; Gotouda, Akihito; Sano, Kazuo

    2016-07-01

    The aim of this study was to elucidate characteristics of rhythmic masticatory muscle activity (RMMA) during sleep by comparing masseteric EMG (electromyogram) activities of RMMA with gum chewing. The parts of five or more consecutive phasic bursts in RMMA of 23 bruxers were analyzed. Wilcoxon signed-rank test for matched pairs and Spearman's correlation coefficient by the rank test were used for statistical analysis. Root mean square value of RMMA phasic burst was smaller than that during gum chewing, but correlates to that of gum chewing. The cycle of RMMA was longer than that of gum chewing due to the longer burst duration of RMMA, and variation in the cycles of RMMA was wider. These findings suggest that the longer but smaller EMG burst in comparison with gum chewing is one of the characteristics of RMMA. The relation between size of RMMA phasic bursts and gum chewing is also suggested.

  10. A comparison of four estimates of Arctic sea ice thickness and volume

    NASA Astrophysics Data System (ADS)

    Tilling, R.; Ridout, A.; Shepherd, A.

    2016-12-01

    In April 2010 the European Space Agency (ESA) CryoSat-2 satellite was launched, providing unprecedented sampling of the Arctic Ocean with a region of coverage extending to 88°N. The first estimates of Arctic sea ice thickness from CryoSat-2 were produced in 2013 [Laxon et al., 2013] by the Centre for Polar Observation and Modelling (CPOM). Since then, a number of other teams have developed alternative CryoSat-2 sea ice processing systems, including NASA [Kurtz et al., 2014], and the Alfred Wegener Institute (AWI) [Ricker et al., 2014]. In addition, the Pan-Arctic Ice-Ocean Modelling and Assimilation System (PIOMAS) model also provides an estimate of Arctic sea ice thickness. These four data records of Arctic sea ice thickness differ in their methods and spatial extent. In this paper, we compare and contrast estimates of sea ice thickness and volume derived from these four data records - the CPOM, NASA, AWI, and PIOMAS systems. We also investigate the sensitivity of each dataset to the application of a time-varying snow load instead of the climatology that is conventionally employed. To facilitate the comparison, sea ice thickness and concentration data are posted on to the same monthly grid to produce equivalent estimates of Arctic sea ice volume. An initial comparison is shown in Figure 1. All of the datasets display, qualitatively, many of the same aspects of the observed variability in volume, including seasonal progression and the step increases in sea ice volume recorded in the autumns of 2013 and 2014. However, CPOM estimates of volume are generally lower than those from AWI in October, similar in November, and higher through the remainder of the growth season. PIOMAS estimates of Arctic sea ice volume are more variable.

  11. Reduced Lower-Limb Muscle Strength and Volume in Patients With Type 2 Diabetes in Relation to Neuropathy, Intramuscular Fat, and Vitamin D Levels

    PubMed Central

    Almurdhi, Monirah M.; Reeves, Neil D.; Bowling, Frank L.; Boulton, Andrew J.M.; Jeziorska, Maria

    2016-01-01

    OBJECTIVE Muscle weakness and atrophy of the lower limbs may develop in patients with diabetes, increasing their risk of falls. The underlying basis of these abnormalities has not been fully explained. The aim of this study was to objectively quantify muscle strength and size in patients with type 2 diabetes mellitus (T2DM) in relation to the severity of neuropathy, intramuscular noncontractile tissue (IMNCT), and vitamin D deficiency. RESEARCH DESIGN AND METHODS Twenty patients with T2DM and 20 healthy control subjects were matched by age, sex, and BMI. Strength and size of knee extensor, flexor, and ankle plantar and dorsiflexor muscles were assessed in relation to the severity of diabetic sensorimotor polyneuropathy (DSPN), amount of IMNCT, and serum 25-hydroxyvitamin D (25OHD) levels. RESULTS Compared with control subjects, patients with T2DM had significantly reduced knee extensor strength (P = 0.003) and reduced muscle volume of both knee extensors (P = 0.045) and flexors (P = 0.019). Ankle plantar flexor strength was also significantly reduced (P = 0.001) but without a reduction in ankle plantar flexor (P = 0.23) and dorsiflexor (P = 0.45) muscle volumes. IMNCT was significantly increased in the ankle plantar (P = 0.006) and dorsiflexors (P = 0.005). Patients with DSPN had significantly less knee extensor strength than those without (P = 0.02) but showed no difference in knee extensor volume (P = 0.38) and ankle plantar flexor strength (P = 0.21) or volume (P = 0.96). In patients with <25 nmol/L versus >25 nmol/L 25OHD, no significant differences were found for knee extensor strength and volume (P = 0.32 vs. 0.18) and ankle plantar flexors (P = 0.58 vs. 0.12). CONCLUSIONS Patients with T2DM have a significant reduction in proximal and distal leg muscle strength and a proximal but not distal reduction in muscle volume possibly due to greater intramuscular fat accumulation in distal muscles. Proximal but not distal muscle strength is related to the severity of

  12. Measuring the volume of uterine fibroids using 2- and 3-dimensional ultrasound and comparison with histopathology.

    PubMed

    Zivković, Nikica; Zivković, Kreiimir; Despot, Albert; Paić, Josip; Zelić, Ana

    2012-12-01

    The aim of this study was clinical testing of the reliability and usability of three-dimensional (3D) and two-dimensional (2D) ultrasound (US) technology. The ultimate aim and purpose of this study was to establish ultrasound methods, standards and protocols for determining the volume of any gynecologic organ or tumor. The study included 31 women in reproductive age and postmenopause. All patients were examined with a RIC 5-9 3D-endovaginal probe (4.3-7.5 MHz) on a Voluson 730 Pro ultrasound device. The volume of myomas was measured by using the existing 2D and 3D ultrasound methods on the above mentioned device. All patients underwent myomectomy or hysterectomy due to clinically and ultrasonographically diagnosed uterine myomas indicating operative intervention. After the operation, the pathologist determined the volume of removed myomas by measuring them in a gauge bowl containing water, i.e. using Archimedes' principle (lift), serving as the control group with histopathologic diagnosis. A total of 155 myoma volumes were processed on 2D display, 31 myoma volumes were preoperatively measured on 3D display and 31 myoma volumes were measured by the pathologist. The values of US measurements for each US method were expressed as mean value of all measurements of myoma volumes. Statistical processing of the results and Student's t-test for independent samples revealed that the 2nd examined US method (measuring of myoma by using an ellipse and the longer tumor diameter) and 4th examined US method (measuring of myoma by using the longer and shorter tumor diameters together with establishing their mean values) in 2D US technique, as well as the 6th examined US method in 3D US technique showed no significant measurement differences in comparison with control measurement in a gauge bowl containing water (p < 0.05), indicating acceptability of the US methods for verifying tumor volumes. The standard error in determining the volume of myomas by the above US methods varied

  13. Comparison of gray matter volume and thickness for analysis of cortical changes in Alzheimer's disease

    NASA Astrophysics Data System (ADS)

    Liu, Jiachao; Li, Ziyi; Chen, Kewei; Yao, Li; Wang, Zhiqun; Li, Kunchen; Guo, Xiaojuan

    2011-03-01

    Gray matter volume and cortical thickness are two indices of concern in brain structure magnetic resonance imaging research. Gray matter volume reflects mixed-measurement information of cerebral cortex, while cortical thickness reflects only the information of distance between inner surface and outer surface of cerebral cortex. Using Scaled Subprofile Modeling based on Principal Component Analysis (SSM_PCA) and Pearson's Correlation Analysis, this study further provided quantitative comparisons and depicted both global relevance and local relevance to comprehensively investigate morphometrical abnormalities in cerebral cortex in Alzheimer's disease (AD). Thirteen patients with AD and thirteen age- and gender-matched healthy controls were included in this study. Results showed that factor scores from the first 8 principal components accounted for ~53.38% of the total variance for gray matter volume, and ~50.18% for cortical thickness. Factor scores from the fifth principal component showed significant correlation. In addition, gray matter voxel-based volume was closely related to cortical thickness alterations in most cortical cortex, especially, in some typical abnormal brain regions such as insula and the parahippocampal gyrus in AD. These findings suggest that these two measurements are effective indices for understanding the neuropathology in AD. Studies using both gray matter volume and cortical thickness can separate the causes of the discrepancy, provide complementary information and carry out a comprehensive description of the morphological changes of brain structure.

  14. Noninvasive, low-noise, fast imaging of blood volume and deoxygenation changes in muscles using light-emitting diode continuous-wave imager

    NASA Astrophysics Data System (ADS)

    Lin, Yuanqing; Lech, Gwen; Nioka, Shoko; Intes, Xavier; Chance, Britton

    2002-08-01

    This article focuses on optimizing the signal to noise ratio (SNR) of a three-wavelength light-emitting diode (LED) near-infrared continuous-wave (cw) imager and its application to in vivo muscle metabolism measurement. The shot-noise limited SNR is derived and calculated to be 2 x104 for the physiological blood concentrations of muscle. Aiming at shot-noise limited SNR performance and fast imaging, we utilize sample and hold circuits to reduce high-frequency noise. These circuits have also been designed to be parallel integrating, through which SNR of 2 x103 and 2 Hz imaging acquisition rate have been achieved when the probe is placed on a muscle model. The noise corresponds to 2 x10-4 optical density error, which suggests an in vitro resolution of 15. 4 nM blood volume and 46.8 nM deoxygenation changes. A 48 dB digital gain control circuit with 256 steps is employed to enlarge the dynamic range of the imager. We utilize cuff ischemia as a living model demonstration and its results are reported. The instrument is applied during exercise to measure the changes of blood volume and deoxygenation, which provides important information about muscle metabolism. We find that the primary source of noise encountered during exercise experiment is from the random motion of muscle. The results demonstrate that the LED cw imager is ideal for the noninvasive study of muscle metabolism.

  15. Age and sex differences in muscle sympathetic nerve activity in relation to haemodynamics, blood volume and left ventricular size.

    PubMed

    Best, Stuart A; Okada, Yoshiyuki; Galbreath, M Melyn; Jarvis, Sara S; Bivens, Tiffany B; Adams-Huet, Beverley; Fu, Qi

    2014-06-01

    We compared the effect of age- and sex-related differences in haemodynamics, blood volume (BV) and left ventricular (LV) size and mass on resting muscle sympathetic nerve activity (MSNA) in healthy, normotensive adults. Twenty young men (19-47 years old) and 20 young women (21-46 years old) as well as 15 older men (62-80 years old) and 15 older women (60-82 years old) were studied. Cardiac output (acetylene rebreathing), total peripheral resistance, forearm vascular resistance (FVR; venous occlusion plethysmography) and MSNA were measured during supine rest. Blood volume was calculated (CO rebreathing), and LV mass, end-diastolic (LVEDV) and end-systolic volumes (LVESV) were measured using magnetic resonance imaging. Cardiac index (P < 0.001 and P = 0.016), BV (both P < 0.001), LV mass (P < 0.001 and P = 0.002), LVEDV (P < 0.001 and P = 0.002) and LVESV (both P < 0.001) were lower in the older and female groups, respectively. Total peripheral resistance was significantly higher in the older (P < 0.001) and female groups (P = 0.014), but FVR was increased in the female groups (P = 0.048) only (age, P = 0.089). The MSNA was greater in the older groups (P < 0.001) only (sex, P = 0.228). Increased MSNA was shown to correlate with a decrease in BV (P = 0.004) in men only when adjusted for age (women, P = 0.133). There was a positive relation between MSNA and FVR (P = 0.020) in men but not women (P = 0.422). There were no significant relations between MSNA and LV mass, LVEDV or LVESV. The findings suggest that the increase in resting MSNA with age may be related to the decline in BV in men only, but it is unknown whether sex differences in sympathetic adrenergic vasoconstriction occur independently of these changes.

  16. Effects of pressure- or volume-overload hypertrophy on passive stiffness in isolated adult cardiac muscle cells

    NASA Technical Reports Server (NTRS)

    Kato, S.; Koide, M.; Cooper, G. 4th; Zile, M. R.

    1996-01-01

    It has been hypothesized that the changes in myocardial stiffness induced by chronic hemodynamic overloading are dependent on changes in the passive stiffness of the cardiac muscle cell (cardiocyte). However, no previous studies have examined the passive constitutive properties of cardiocytes isolated from animals with myocardial hypertrophy. Accordingly, changes in relative passive stiffness of cardiocytes isolated from animals with chronic pressure- or volume-overload hypertrophy were determined by examining the effects of anisosmotic stress on cardiocyte size. Anisosmotic stress was produced by altering superfusate osmolarity. Hypertrophied cardiocytes were enzymatically isolated from 16 adult cats with right ventricular (RV) pressure-overload hypertrophy induced by pulmonary artery banding (PAB) and from 6 adult cats with RV volume-overload hypertrophy induced by creating an atrial septal defect (ASD). Left ventricular (LV) cardiocytes from each cat served as nonhypertrophied, normally loaded, same-animal controls. Superfusate osmolarity was decreased from 305 +/- 3 to 135 +/- 5 mosM and increased to 645 +/- 4 mosM. During anisosmotic stress, there were no significant differences between hypertrophied RV and normal LV cardiocytes in pressure overload PAB cats with respect to percent change in cardiocyte area (47 +/- 2% in RV vs. 48 +/- 2% in LV), diameter (46 +/- 3% in RV vs. 48 +/- 2% in LV), or length (2.4 +/- 0.2% in RV vs. 2.0 +/- 0.3% in LV), or sarcomere length (1.5 +/- 0.1% in RV vs. 1.3 +/- 0.3% in LV). Likewise, there were no significant differences in cardiocyte strain between hypertrophied RV and normal LV cardiocytes from ASD cats. In conclusion, chronic pressure-overload hypertrophy and chronic volume-overload hypertrophy did not alter the cardiocyte response to anisosmotic stress. Thus chronic overload hypertrophy did not alter relative passive cardiocyte stiffness.

  17. Effects of pressure- or volume-overload hypertrophy on passive stiffness in isolated adult cardiac muscle cells

    NASA Technical Reports Server (NTRS)

    Kato, S.; Koide, M.; Cooper, G. 4th; Zile, M. R.

    1996-01-01

    It has been hypothesized that the changes in myocardial stiffness induced by chronic hemodynamic overloading are dependent on changes in the passive stiffness of the cardiac muscle cell (cardiocyte). However, no previous studies have examined the passive constitutive properties of cardiocytes isolated from animals with myocardial hypertrophy. Accordingly, changes in relative passive stiffness of cardiocytes isolated from animals with chronic pressure- or volume-overload hypertrophy were determined by examining the effects of anisosmotic stress on cardiocyte size. Anisosmotic stress was produced by altering superfusate osmolarity. Hypertrophied cardiocytes were enzymatically isolated from 16 adult cats with right ventricular (RV) pressure-overload hypertrophy induced by pulmonary artery banding (PAB) and from 6 adult cats with RV volume-overload hypertrophy induced by creating an atrial septal defect (ASD). Left ventricular (LV) cardiocytes from each cat served as nonhypertrophied, normally loaded, same-animal controls. Superfusate osmolarity was decreased from 305 +/- 3 to 135 +/- 5 mosM and increased to 645 +/- 4 mosM. During anisosmotic stress, there were no significant differences between hypertrophied RV and normal LV cardiocytes in pressure overload PAB cats with respect to percent change in cardiocyte area (47 +/- 2% in RV vs. 48 +/- 2% in LV), diameter (46 +/- 3% in RV vs. 48 +/- 2% in LV), or length (2.4 +/- 0.2% in RV vs. 2.0 +/- 0.3% in LV), or sarcomere length (1.5 +/- 0.1% in RV vs. 1.3 +/- 0.3% in LV). Likewise, there were no significant differences in cardiocyte strain between hypertrophied RV and normal LV cardiocytes from ASD cats. In conclusion, chronic pressure-overload hypertrophy and chronic volume-overload hypertrophy did not alter the cardiocyte response to anisosmotic stress. Thus chronic overload hypertrophy did not alter relative passive cardiocyte stiffness.

  18. Correlating 2D histological slice with 3D MRI image volume using smart phone as an interactive tool for muscle study.

    PubMed

    Eresen, Aydin; Li, Peng; Ji, Jim Xiuquan

    2014-01-01

    In muscle dystrophy studies, registration of histological image with MRI image volume enables cross validation of MRI biomarkers using pathological result. However, correlation of 2D histology slice with 3D MRI volume is technically challenging due to the potentially non-orthogonal slice plane and incomplete or distorted histological slice. This paper presents an efficient method to directly perform the 2D-3D registration. The method is unique in that it uses smart phone as a navigation tool for initial alignment followed by an overlap invariant mutual information-based refinement. Experimental results using animal muscle samples images from a 3T MRI and HE stained histological images show that the proposed method is capable of aligning the histological slice with an oblique slice in MR volume.

  19. Special computer-aided computed tomography (CT) volume measurement and comparison method for pulmonary tuberculosis (TB).

    PubMed

    Liu, Jingming; Sun, Zhaogang; Xie, Ruming; Gao, Mengqiu; Li, Chuanyou

    2015-01-01

    The computed tomography (CT) manifestations in pulmonary tuberculosis (PTB) patients are complex and could not be quantitatively evaluated. We aimed to establish a new method to objectively measure the lung injury level in PTB by thoracic CT and make quantitative comparisons. In the retrospective study, a total of 360 adults were selected and divided into four groups according to their CT manifestations and medical history: Normal group, PTB group, PTB with diabetes mellitus (DM) group and Death caused by PTB group. Five additional patients who had continuous CT scans were chosen for preliminary longitudinal analysis. We established a new computer-aided CT volume measurement and comparison method for PTB patients (CACTV-PTB) which measured lung volume (LV) and thoracic volume (TV). RLT was calculated as the ratio of LV to TV and comparisons were performed among different groups. Standardized RLT (SRLT) was used in the longitudinal analysis among different patients. In the Normal group, LV and TV were positively correlated in linear regression (Ŷ=-0.5+0.46X, R(2)=0.796, P<0.01). RLT values were significantly different among four groups (Normal: 0.40±0.05, PTB: 0.37±0.08, PTB+DM: 0.34±0.06, Death: 0.23±0.04). The curves of SRLT value from different patients shared a same start point and could be compared directly. Utilizing the novel objective method CACTV-PTB makes it possible to compare the severity and dynamic change among different PTB patients. Our early experience also suggested that the lung injury is severer in the PTB+DM group than in the PTB group.

  20. Validation of Interstitial Fractional Volume Quantification by Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Porcine Skeletal Muscles.

    PubMed

    Hindel, Stefan; Söhner, Anika; Maa, Marc; Sauerwein, Wolfgang; Baba, Hideo Andreas; Kramer, Martin; Lüdemann, Lutz

    2017-01-01

    The aim of our study was to assess the accuracy of fractional interstitial volume determination in low perfused and low vascularized tissue by using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). The fractional interstitial volume (ve) was determined in the medial thigh muscle of 12 female pigs by using a 3-dimensional gradient echo sequence with k-space sharing and administering gadolinium-based contrast agent (gadoterate meglumine). Analysis was performed using 3 pharmacokinetic models: the simple Tofts model (TM), the extended TM (ETM), and the 2-compartment exchange model (2CXM). We investigated the effect of varying acquisition durations (ADs) on the model parameter estimates of the 3 models and compared the ve values with the results of histological examinations of muscle sections of the medial thigh muscle. Histological measurements yielded a median value (25%-75% quartile) of 4.8% (3.7%-6.2%) for ve. The interstitial fractional volume determined by DCE-MRI was comparable to the histological results but varied strongly with AD for the TM and ETM. For the TM and the ETM, the results were virtually the same. Choosing arterial hematocrit to Hcta = 0.4, the lowest median ve value determined by DCE-MRI was 5.2% (3.3%-6.1%) for the ETM at a 6-minute AD. The maximum ve value determined with the ETM at a 15-minute AD was 7.7% (4.5%-9.0%). The variation with AD of median ve values obtained with the 2CXM was much smaller: 6.2% (3.1%-9.2%) for the 6-minute AD and 6.3% (4.3%-9.8%) for the 15-minute AD. The best fit for the 2CXM was found at the 10-minute AD with ve values of 6.6% (3.7%-8.2%). No significant correlation between the histological and any DCE-MRI modeling results was found. Considering the expected accuracy of histological measurements, the medians of the MR modeling results were in good agreement with the histological prediction. A parameter determination uncertainty was identified with the use of the TMs. This is due to underfitting and

  1. Capillary ultrastructure and mitochondrial volume density in skeletal muscle in relation to reduced exercise capacity of patients with intermittent claudication.

    PubMed

    Baum, Oliver; Torchetti, Eleonora; Malik, Corinna; Hoier, Birgitte; Walker, Meegan; Walker, Philip J; Odriozola, Adolfo; Graber, Franziska; Tschanz, Stefan A; Bangsbo, Jens; Hoppeler, Hans; Askew, Christopher D; Hellsten, Ylva

    2016-05-15

    Intermittent claudication (IC) is the most commonly reported symptom of peripheral arterial disease (PAD). Impaired limb blood flow is a major casual factor of lower exercise tolerance in PAD but cannot entirely explain it. We hypothesized that IC is associated with structural changes of the capillary-mitochondria interface that could contribute to the reduction of exercise tolerance in IC patients. Capillary and mitochondrial morphometry were performed after light and transmission electron microscopy using vastus lateralis muscle biopsies of 14 IC patients and 10 age-matched controls, and peak power output (PPO) was determined for all participants using an incremental single-leg knee-extension protocol. Capillary density was lower (411 ± 90 mm(-2) vs. 506 ± 95 mm(-2); P ≤ 0.05) in the biopsies of the IC patients than in those of the controls. The basement membrane (BM) around capillaries was thicker (543 ± 82 nm vs. 423 ± 97 nm; P ≤ 0.01) and the volume density of mitochondria was lower (3.51 ± 0.56% vs. 4.60 ± 0.74%; P ≤ 0.01) in the IC patients than the controls. In the IC patients, a higher proportion of capillaries appeared with collapsed slit-like lumen and/or swollen endothelium. PPO was lower (18.5 ± 9.9 W vs. 33.5 ± 9.4 W; P ≤ 0.01) in the IC patients than the controls. We suggest that several structural alterations in skeletal muscle, either collectively or separately, contribute to the reduction of exercise tolerance in IC patients.

  2. Whole-body and segmental muscle volume are associated with ball velocity in high school baseball pitchers

    PubMed Central

    Yamada, Yosuke; Yamashita, Daichi; Yamamoto, Shinji; Matsui, Tomoyuki; Seo, Kazuya; Azuma, Yoshikazu; Kida, Yoshikazu; Morihara, Toru; Kimura, Misaka

    2013-01-01

    The aim of the study was to examine the relationship between pitching ball velocity and segmental (trunk, upper arm, forearm, upper leg, and lower leg) and whole-body muscle volume (MV) in high school baseball pitchers. Forty-seven male high school pitchers (40 right-handers and seven left-handers; age, 16.2 ± 0.7 years; stature, 173.6 ± 4.9 cm; mass, 65.0 ± 6.8 kg, years of baseball experience, 7.5 ± 1.8 years; maximum pitching ball velocity, 119.0 ± 9.0 km/hour) participated in the study. Segmental and whole-body MV were measured using segmental bioelectrical impedance analysis. Maximum ball velocity was measured with a sports radar gun. The MV of the dominant arm was significantly larger than the MV of the non-dominant arm (P < 0.001). There was no difference in MV between the dominant and non-dominant legs. Whole-body MV was significantly correlated with ball velocity (r = 0.412, P < 0.01). Trunk MV was not correlated with ball velocity, but the MV for both lower legs, and the dominant upper leg, upper arm, and forearm were significantly correlated with ball velocity (P < 0.05). The results were not affected by age or years of baseball experience. Whole-body and segmental MV are associated with ball velocity in high school baseball pitchers. However, the contribution of the muscle mass on pitching ball velocity is limited, thus other fundamental factors (ie, pitching skill) are also important. PMID:24379713

  3. The periodization of resistance training in soccer players: changes in maximal strength, lower extremity power, body composition, and muscle volume.

    PubMed

    Barjaste, Amir; Mirzaei, Bahman

    2017-02-22

    The purpose of this study was to investigate the effect of 12-weeks traditional periodized resistance training on some physical capacities of soccer players. Eighteen amateur soccer players with very little experience in resistance training voluntarily participated in this study. Subjects were assigned into two groups; Experimental (EX) group (n: 10) that conducted a traditional linear periodized resistance training program and a control (C) group (n: 8) that did not participate in any resistance training. Periodized resistance training in two mesocycles was used in this study: general or anatomical adaptation phase (6 wk, 65%-75% of 1RM, eleven exercises in each session) and maximal strength phase (6 wk, 85%-95% of 1RM, three to four exercises in each session). One Repetition Maximum (1RM) strength in lower and upper body, Vertical Jump (VJ) height, Body Composition, and Muscle Volume were measured at three different time points; baseline, after general phase, and after maximal strength phase. The average of the increase in 1RM all exercises in general phase was greater than the maximal strength phase, on average 29.38% and 9.67% respectively (P≤0.05). Also, the Percentage of change in VJ height in general phase was greater than the maximal strength phase (11.93% vs 3.97% respectively) (P≤0.05).0 CONCLUSIONS: The results of this study indicated that muscle strength and explosive performance in players with the little experience in resistance training can be significantly improved with the completion of general phase of resistance training periodization using moderate loads.

  4. A Comparison of Height-Accumulation and Volume-Equation Methods for Estimating Tree and Stand Volumes

    Treesearch

    R.B. Ferguson; V. Clark Baldwin

    1995-01-01

    Estimating tree and stand volume in mature plantations is time consuming, involving much manpower and equipment; however, several sampling and volume-prediction techniques are available. This study showed that a well-constructed, volume-equation method yields estimates comparable to those of the often more time-consuming, height-accumulation method, even though the...

  5. Comparison of excitatory currents activated by different transmitters on crustacean muscle. II. Glutamate-activated currents and comparison with acetylcholine currents present on the same muscle.

    PubMed

    Lingle, C; Auerbach, A

    1983-04-01

    The properties of glutamate-activated excitatory currents on the gm6 muscle from the foregut of the spiny lobsters Panulirus argus and interruptus and the crab Cancer borealis were examined using either noise analysis, analysis of synaptic current decays, or slow iontophoretic currents. The properties of acetylcholine currents activated in nonjunctional regions of the gm6 muscle were also examined. At 12 degrees C and -80 mV, the predominant time constant of power spectra from glutamate-activated current noise was approximately 7 ms and the elementary conductance was approximately 34 pS. At 12 degrees C and -80 mV, the predominant time constant of acetylcholine-activated channels was approximately 11 ms with a conductance of approximately 12 pS. Focally recorded glutamatergic extracellular synaptic currents on the gm6 muscle decayed with time constants of approximately 7-8 ms at 12 degrees C and -80 mV. The decay time constant was prolonged e-fold about every 225-mV hyperpolarization in membrane potential. The Q10 of the time constant of the synaptic current decay was approximately 2.6. The voltage dependence of the steady-state conductance increase activated by iontophoretic application of glutamate has the opposite direction of the steady-state conductance activated by cholinergic agonists when compared on the gm6 muscles. The glutamate-activated conductance increase is diminished with hyperpolarization. The properties of the marine crustacean glutamate channels are discussed in relation to glutamate channels in other organisms and to the acetylcholine channels found on the gm6 muscle and the gm1 muscle of the decapod foregut (Lingle and Auerbach, 1983).

  6. Comparison between the effects of muscle relaxation and support groups on the anxiety of nursing students: A randomized controlled trial.

    PubMed

    Torabizadeh, Camellia; Bostani, Sanaz; Yektatalab, Shahrzad

    2016-11-01

    To compare the effects of the two methods of muscle relaxation and support group on the anxiety levels of the nursing students. In this randomized controlled trial, 150 nursing students who met the inclusion criteria were divided into three equal groups-muscle relaxation, support group, and control-using the permuted-block randomization method. The experimental groups received 5 sessions of intervention, while the control group did not receive any intervention at all. Using Spielberger's inventory, the researchers measured the anxiety levels of all three groups before and after the intervention. The results showed that both methods had a significant impact on anxiety levels of the nursing students; however, a comparison between their effects revealed that muscle relaxation had been more effective than support group. Considering the seriousness of the issue of anxiety for nursing students, it is important that measures be taken to reduce anxiety in this group. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Lung volume assessment for a cross-comparison of two breathing-adapted techniques in radiotherapy

    SciTech Connect

    Simon, Luc . E-mail: luc.simon@curie.net; Giraud, Philippe; Servois, Vincent; Rosenwald, Jean-Claude

    2005-10-01

    Purpose: To assess the validity of gated radiotherapy of lung by using a cross-check methodology based on four-dimensional (4D)-computed tomography (CT) exams. Variations of volume of a breathing phantom was used as an indicator. Methods and Materials: A balloon was periodically inflated and deflated by a medical ventilator. The volume variation ({delta}V) of the balloon was measured simultaneously by a spirometer, taken as reference, and by contouring 4D-CT series (10 phases) acquired by the real-time position management system (RPM). Similar cross-comparison was performed for 2 lung patients, 1 with free breathing (FB), the other with deep-inspiration breath-hold (DIBH) technique. Results: During FB, {delta}V measured by the spirometer and from 4D-CT were in good agreement: the mean differences for all phases were 8.1 mL for the balloon and 10.5 mL for a patient-test. End-inspiration lung volume has been shown to be slightly underestimated by the 4D-CT. The discrepancy for {delta}V between DIBH and end-expiration, measured from CT and from spirometer, respectively, was less than 3%. Conclusions: Provided that each slice series is correctly associated with the proper breathing phase, 4D-CT allows an accurate assessment of lung volume during the whole breathing cycle ({delta}V error <3% compared with the spirometer signal). Taking the lung volume variation into account is a central issue in the evaluation and control of the toxicity for lung radiation treatments.

  8. Muscle plasticity: comparison of a 30-Hz burst with 10-Hz continuous stimulation.

    PubMed

    Ferguson, A S; Stone, H E; Roessmann, U; Burke, M; Tisdale, E; Mortimer, J T

    1989-03-01

    The changes in the contractile properties induced by a 30-Hz phasic stimulation paradigm were measured and compared with the changes induced by a 10-Hz continuous stimulation paradigm. The study was performed on the tibialis anterior muscles of cats with one paradigm applied to one hindlimb muscle and the other to the contralateral limb. Both hindlimb muscles received the same number of stimuli in a day, making the average stimulation frequency 10 Hz. Two periods of daily stimulation were studied, 8 and 24 h/day. Muscles stimulated at 30 Hz produced greater overall tetanic tension and, during a prolonged stimulation test, exerted a greater mean tension than muscles stimulated at 10 Hz (50 and 32% increase for animals stimulated for 8 and 24 h/day, respectively). Muscle mass was least reduced and fewer pathological abnormalities were observed in the muscles stimulated at 30 Hz. There were no apparent differences in the histochemistry or biochemistry between muscles stimulated at 10 and 30 Hz, which could account for these differences in muscle properties. These results indicate the 30-Hz paradigm may be better suited than 10 Hz continuous stimulation for applications requiring sustained muscle tension such as correction of scoliosis or muscle conditioning for motor prostheses.

  9. Comparison of Guidelines on Non-Muscle Invasive Bladder Cancer (EAU, CUA, AUA, NCCN, NICE).

    PubMed

    Power, Nicholas E; Izawa, Jonathan

    2016-01-07

    Non-muscle invasive bladder cancer (NMIBC) represents a considerably diverse patient group and the management of this complex disease is debatable. A number of panels from Europe and North America have convened on the topic and recently released guideline documents. The purpose was to compare and contrast the NMIBC guideline recommendations from the EAU (Europe), CUA (Canada), NCCN (United States), AUA (United States), and NICE (United Kingdom). All unabridged guideline documents were reviewed by the authors and comparisons were completed according to major topics in NMIBC. Despite a paucity of high level evidence regarding the majority of management topics in NMIBC, there was general agreement among the various guideline panels. Differences mainly centered on the categories of evidence synthesized and grades of recommendations. Each document offers a unique presentation of the available literature and guideline recommendation. The guidelines for NMIBC from the EAU, CUA, AUA, NCCN, and NICE provide considerable consensus regarding the management of this often difficult disease. Clinicians are encouraged to familiarize themselves with all of the guidelines in order to determine which style of presentation would be most useful to their current practice.

  10. Sarcomere-length dependence of lattice volume and radial mass transfer of myosin cross-bridges in rat papillary muscle.

    PubMed

    Yagi, Naoto; Okuyama, Hiroshi; Toyota, Hiroko; Araki, Junichi; Shimizu, Juichiro; Iribe, Gentaro; Nakamura, Kazufumi; Mohri, Satoshi; Tsujioka, Katsuhiko; Suga, Hiroyuki; Kajiya, Fumihiko

    2004-05-01

    We examined the sarcomere length-dependence of the spacing of the hexagonal lattice of the myofilaments and the mass transfer of myosin cross-bridges during contraction of right ventricular papillary muscle of the rat. The lattice spacing and mass transfer were measured by using X-ray diffraction, and the sarcomere length was monitored by laser diffraction at the same time. Although the lattice spacing and the sarcomere length were inversely related, their relationship was not exactly isovolumic. The cell volume decreased by about 15% when the sarcomere length was shortened from 2.3 micro m to 1.8 micro m. Twitch tension increased with sarcomere length (the Frank-Starling law). At the peak tension, the ratio of the intensity of the (1,0) equatorial reflection to that of the (1,1) reflection was smaller when the tension was greater, showing that the larger tension at a longer sarcomere length accompanies a larger amount of mass transfer of cross-bridges from the thick to the thin filament. The result suggests that the Frank-Starling law is due to an increase in the number of myosin heads attached to actin, not in the average force produced by each head.

  11. Interrater Reliability and Physical Examination of the Pubovisceral Portion of the Levator Ani Muscle, Validity Comparisons using MR Imaging

    PubMed Central

    Kearney, Rohna; Miller, Janis M.; DeLancey, John O. L.

    2009-01-01

    Aims Defects in the pubovisceral portion of the levator ani muscle are seen with MR imaging. This study aims to determine interrater reliability of physical examination in detecting these defects, and to validate findings from physical examination using comparisons with MR images Methods Two examiners palpated the pubovisceral muscles of 29 women to assess for defects in this muscle. Each examiner was blinded to the others findings. MR scans were acquired on a further 24 women after structured clinical examination by one examiner. These images were read to determine pubovisceral muscle defects, blinded to patient identifiers. Agreement between raters and between MR imaging and clinical examination were calculated. Results The two examiners had positive agreement (presence of a defect) of 72.7% and negative agreement (absence of a defect) of 83.3%. The positive agreement between physical examination and MR imaging was 27.3% and the negative agreement 86.5% Conclusion The structured physical examination to detect defects in the pubovisceral portion of the levator ani muscle can be learned as shown by good interrater agreement. However, examination alone underestimates these defects compared with MR imaging. PMID:16304674

  12. Comparison of /sup 45/Ca binding and mobilization in cartilage and smooth muscle of guinea pig trachea

    SciTech Connect

    Goodman, F.R.; Weiss, G.B.; Sturm, B.

    1986-03-01

    In guinea pig trachea, separation of smooth muscle from cartilage permits measurement of /sup 45/Ca fluxes in more homogeneous preparations. The role of cartilage Ca/sup + +/ as a source for smooth muscle Ca/sup + +/ mobilization can be assessed by similar experiments with the two dissociated preparations. Equilibration of /sup 45/Ca into cartilage occurred over 2 hr; plotting of /sup 45/Ca uptake on Scatchard coordinates yields high and low affinity Ca/sup + +/ uptake components similar to those in tracheal and other smooth muscles. Washout of /sup 45/Ca from cartilage demonstrated two components with the more rapid including the extracellular (/sup 14/C-sucrose) compartment. Washout of higher affinity /sup 45/Ca (after incubation in 0.03 mM Ca/sup + +/) was increased in cartilage by Sr/sup + +/, added Ca/sup + +/, La/sup + + +/ and EGTA. Comparison with tracheal smooth muscle /sup 45/Ca washouts indicates that those Ca/sup + +/ components previously identified as of intracellular origin were not present in cartilage. Exposure to 60 mM (added) K/sup +/ during /sup 45/Ca washout increased /sup 45/Ca efflux in cartilage but not in smooth muscle. This release of /sup 45/Ca by K/sup +/ may indicate that Ca/sup + +/ can be mobilized from cartilage sites by K/sup +/ to support smooth muscle contractile responses. Thus, cartilage Ca/sup + +/ could be an important source of Ca/sup + +/ for excitation-contraction coupling in guinea pig tracheal smooth muscle.

  13. Music assisted progressive muscle relaxation, progressive muscle relaxation, music listening, and silence: a comparison of relaxation techniques.

    PubMed

    Robb, S L

    2000-01-01

    The purpose of this study was to compare the effects of music assisted progressive muscle relaxation (M + PMR), progressive muscle relaxation (PMR), music listening, and silence/suggestion on measures of anxiety and perceived relaxation. The study also examined participant responses to a posttreatment questionnaire to identify relationships between musical and nonmusical elements in relaxation techniques. Sixty university students participated in the study. Fifteen participants were randomly assigned to each treatment condition. Subjects were tested individually using the same relaxation script for M + PMR and PMR conditions. One-way analyses of covariance were computed to compare pre and posttest differences among groups. Results of the ANCOVA revealed no differences among groups for the State Trait Anxiety Inventory (STAI) or the Visual Analog Scale (VAS). Analysis of variance, however, revealed each treatment condition to be equally effective in producing significant changes in anxiety and perceived relaxation from the pre to posttest period. Additionally, mean score differences revealed decreases for all conditions with M + PMR eliciting the greatest amount of change. A content analysis of posttreatment questionnaire items revealed detailed information about each participant's relaxation experience, state of mind, and use of self-generated relaxation techniques.

  14. DIFFERENT RECOVERY METHODS AND MUSCLE PERFORMANCE AFTER EXHAUSTING EXERCISE: COMPARISON OF THE EFFECTS OF ELECTRICAL MUSCLE STIMULATION AND MASSAGE

    PubMed Central

    Kaya, F.; Bicer, B.; Erzeybek, M.S.; Cotuk, H.B.

    2012-01-01

    In this study we assessed the influence of the three different recovery interventions massage (MSG), electrical muscle stimulation (EMS), and passive rest (PR) on lactate disappearance and muscle recovery after exhausting exercise bouts. Twelve healthy male sport students participated in the study. They attended the laboratory on five test days. After measurement of V.O2max and a baseline Wingate test (WGb), the three recovery interventions were tested in random counterbalanced order. High intensity exercise, which consisted of six exhausting exercise bouts (interspersed with active recovery), was followed by MSG, EMS or PR application (24 minutes); then the final Wingate test (WGf) was performed. Lactate, heart rate, peak and mean power, rating of perceived exertion (RPE), and total quality of recovery (TQR) were recorded. In WGf mean power was significantly higher than in WGb for all three recovery modalities (MSG 6.29%, EMS 5.33%, PR 4.84% increase, p < 0.05), but no significant differences in mean and peak power were observed between the three recovery modes (p > 0.05). The heart rate response and the changes in blood lactate concentration were identical in all three interventions during the entire protocol (p = 0.817, p = 0.493, respectively). RPE and TQR scores were also not different among the three interventions (p > 0.05). These results provide further evidence that MSG and EMS are not more effective than PR in the process of recovery from high intensity exercise. PMID:24868117

  15. Effects of Low-Intensity Cycle Training with Restricted Leg Blood Flow on Thigh Muscle Volume and VO2MAX in Young Men.

    PubMed

    Abe, Takashi; Fujita, Satoshi; Nakajima, Toshiaki; Sakamaki, Mikako; Ozaki, Hayao; Ogasawara, Riki; Sugaya, Masato; Kudo, Maiko; Kurano, Miwa; Yasuda, Tomohiro; Sato, Yoshiaki; Ohshima, Hiroshi; Mukai, Chiaki; Ishii, Naokata

    2010-01-01

    Concurrent improvements in aerobic capacity and muscle hypertrophy in response to a single mode of training have not been reported. We examined the effects of low-intensity cycle exercise training with and without blood flow restriction (BFR) on muscle size and maximum oxygen uptake (VO2max). A group of 19 young men (mean age ± SD: 23.0 ± 1.7 years) were allocated randomly into either a BFR-training group (n=9, BFR-training) or a non-BFR control training group (n=10, CON-training), both of which trained 3 days/wk for 8 wk. Training intensity and duration were 40% of VO2max and 15 min for the BFR-training group and 40% of VO2max and 45 min for the CON-training group. MRI-measured thigh and quadriceps muscle cross-sectional area and muscle volume increased by 3.4-5.1% (P < 0.01) and isometric knee extension strength tended to increase by 7.7% (p < 0.10) in the BFR-training group. There was no change in muscle size (~0.6%) and strength (~1.4%) in the CON-training group. Significant improvements in VO2max (6.4%) and exercise time until exhaustion (15.4%) were observed in the BFR-training group (p < 0.05) but not in the CON-training group (-0.1 and 3. 9%, respectively). The results suggest that low-intensity, short-duration cycling exercise combined with BFR improves both muscle hypertrophy and aerobic capacity concurrently in young men. Key pointsConcurrent improvements in aerobic capacity and muscle hypertrophy in response to a single mode of training have not been reported.In the present study, low-intensity (40% of VO2max) cycle training with BFR can elicit concurrent improvement in muscle hypertrophy and aerobic capacity.

  16. A comparison of bone regeneration with human mesenchymal stem cells and muscle-derived stem cells and the critical role of BMP.

    PubMed

    Gao, Xueqin; Usas, Arvydas; Tang, Ying; Lu, Aiping; Tan, Jian; Schneppendahl, Johannes; Kozemchak, Adam M; Wang, Bing; Cummins, James H; Tuan, Rocky S; Huard, Johnny

    2014-08-01

    Adult multipotent stem cells have been isolated from a variety of human tissues including human skeletal muscle, which represent an easily accessible source of stem cells. It has been shown that human skeletal muscle-derived stem cells (hMDSCs) are muscle-derived mesenchymal stem cells capable of multipotent differentiation. Although hMDSCs can undergo osteogenic differentiation and form bone when genetically modified to express BMP2; it is still unclear whether hMDSCs are as efficient as human bone marrow mesenchymal stem cells (hBMMSCs) for bone regeneration. The current study aimed to address this question by performing a parallel comparison between hMDSCs and hBMMSCs to evaluate their osteogenic and bone regeneration capacities. Our results demonstrated that hMDSCs and hBMMSCs had similar osteogenic-related gene expression profiles and had similar osteogenic differentiation capacities in vitro when transduced to express BMP2. Both the untransduced hMDSCs and hBMMSCs formed very negligible amounts of bone in the critical sized bone defect model when using a fibrin sealant scaffold; however, when genetically modified with lenti-BMP2, both populations successfully regenerated bone in the defect area. No significant differences were found in the newly formed bone volumes and bone defect coverage between the hMDSC and hBMMSC groups. Although both cell types formed mature bone tissue by 6 weeks post-implantation, the newly formed bone in the hMDSCs group underwent quicker remodelling than the hBMMSCs group. In conclusion, our results demonstrated that hMDSCs are as efficient as hBMMSCs in terms of their bone regeneration capacity; however, both cell types required genetic modification with BMP in order to regenerate bone in vivo.

  17. Extraocular Muscle Compartments in Superior Oblique Palsy

    PubMed Central

    Suh, Soh Youn; Clark, Robert A.; Le, Alan; Demer, Joseph L.

    2016-01-01

    Purpose To investigate changes in volumes of extraocular muscle (EOM) compartments in unilateral superior oblique (SO) palsy using magnetic resonance imaging (MRI). Methods High-resolution, surface-coil MRI was obtained in 19 patients with unilateral SO palsy and 19 age-matched orthotropic control subjects. Rectus EOMs and the SO were divided into two anatomic compartments for volume analysis in patients with unilateral SO palsy, allowing comparison of total compartmental volumes versus controls. Medial and lateral compartmental volumes of the SO muscle were compared in patients with isotropic (round shape) versus anisotropic (elongated shape) SO atrophy. Results The medial and lateral compartments of the ipsilesional SO muscles were equally atrophic in isotropic SO palsy, whereas the lateral compartment was significantly smaller than the medial in anisotropic SO palsy (P = 0.01). In contrast to the SO, there were no differential compartmental volume changes in rectus EOMs; however, there was significant total muscle hypertrophy in the ipsilesional inferior rectus (IR) and lateral rectus (LR) muscles and contralesional superior rectus (SR) muscles. Medial rectus (MR) volume was normal both ipsi- and contralesionally. Conclusions A subset of patients with SO palsy exhibit selective atrophy of the lateral, predominantly vertically acting SO compartment. Superior oblique atrophy is associated with whole-muscle volume changes in the ipsilesional IR, ipsilesional LR, and contralesional SR; however, SO muscle atrophy is not associated with compartmentally selective volume changes in the rectus EOMs. Selective compartmental SO pathology may provide an anatomic mechanism that explains some of the variability in clinical presentations of SO palsy. PMID:27768791

  18. Volume quantification by contrast-enhanced ultrasound: an in-vitro comparison with true volumes and thermodilution

    PubMed Central

    2013-01-01

    Background Contrast-enhanced ultrasound (CEUS) has recently been proposed as a minimally- invasive, alternative method for blood volume measurement. This study aims at comparing the accuracy of CEUS and the classical thermodilution techniques for volume assessment in an in-vitro set-up. Methods The in-vitro set-up consisted of a variable network between an inflow and outflow tube and a roller pump. The inflow and outflow tubes were insonified with an ultrasound array transducer and a thermistor was placed in each tube. Indicator dilution curves were made by injecting indicator which consisted of an ultrasound-contrast-agent diluted in ice-cold saline. Both acoustic intensity- and thermo-dilution curves were used to calculate the indicator mean transit time between the inflow and outflow tube. The volumes were derived by multiplying the estimated mean transit time by the flow rate. We compared the volumes measured by CEUS with the true volumes of the variable network and those measured by thermodilution by Bland-Altman and intraclass-correlation analysis. Results The measurements by CEUS and thermodilution showed a very strong correlation (rs = 0.94) with a modest volume underestimation by CEUS of −40 ± 28 mL and an overestimation of 84 ± 62 mL by thermodilution compared with the true volumes. Both CEUS and thermodilution showed a high statistically significant correlation with the true volume (rs = 0.97 (95% CI, 0.95 - 0.98; P<0.0001) and rs = 0.96 (95% CI, 0.94 - 0.98; P<0.0001, respectively). Conclusions CEUS volume estimation provides a strong correlation with both the true volumes in-vitro and volume estimation by thermodilution. It may therefore represent an interesting alternative to the standard, invasive thermodilution technique. PMID:24134671

  19. Effects of muscle dysmorphia, social comparisons and body schema priming on desire for social interaction: an experimental approach.

    PubMed

    Schneider, Catharina; Agthe, Maria; Yanagida, Takuya; Voracek, Martin; Hennig-Fast, Kristina

    2017-06-15

    Muscle dysmorphia (MD) is a relatively young diagnosis referring to the desire for a high degree in lean muscle mass, while simultaneously believing that one is insufficiently muscular, mostly found in men. It goes along with a risk for social withdrawal to maintain rigid exercise and dietary regimen. The aim of the current study was thus, to explore differences in men with and without a risk for muscle dysmorphia regarding their desire for social interaction. Furthermore, we investigated potential effects of individual social comparison tendencies (the tendency to compare oneself with persons who are perceived to be superior or inferior to oneself on a certain dimension) and of one's own body schema on the desire for social interaction. One hundred physically active, college aged Austrian men were recruited via social media and flyers at fitness centers and the sports department of the University of Vienna. Participants were randomly assigned to a priming condition evoking their own body schema or a control condition and had to state their desire for social interaction with male or female stimulus persons of high or average attractiveness. We conducted a 2 (group of participant; men with vs. without a risk for MD) × 2 (priming condition; priming vs. non-priming) × 2 (attractiveness of stimulus person; highly attractive vs. less attractive) experimental design with different social comparison tendencies as covariates. Men with a risk for muscle dysmorphia showed lesser desire for social interaction than men without this risk, which can be seen as a risk factor for psychopathological outcomes. Generally, men with and without a risk for muscle dysmorphia did not differ with regard to their preferences for attractive stimulus persons as subjects for social interaction. We confirmed the notion that a tendency for downward social comparisons goes along with a diminished desire for social interaction. This study showed that men with a risk for muscle dysmorphia

  20. Internal photoemission from plasmonic nanoparticles: comparison between surface and volume photoelectric effects.

    PubMed

    Uskov, Alexander V; Protsenko, Igor E; Ikhsanov, Renat S; Babicheva, Viktoriia E; Zhukovsky, Sergei V; Lavrinenko, Andrei V; O'Reilly, Eoin P; Xu, Hongxing

    2014-05-07

    We study the emission of photoelectrons from plasmonic nanoparticles into a surrounding matrix. We consider two mechanisms of electron emission from the nanoparticles--surface and volume ones--and use models for these two mechanisms which allow us to obtain analytical results for the photoelectron emission rate from a nanoparticle. Calculations have been carried out for a step potential at the surface of a spherical nanoparticle, and a simple model for the hot electron cooling has been used. We highlight the effect of the discontinuity of the dielectric permittivity at the nanoparticle boundary in the surface mechanism, which leads to a substantial (by ∼5 times) increase of the internal photoelectron emission rate from a nanoparticle compared to the case when such a discontinuity is absent. For a plasmonic nanoparticle, a comparison of the two photoeffect mechanisms was undertaken for the first time which showed that the surface photoeffect can in the general case be larger than the volume one, which agrees with the results obtained for a flat metal surface first formulated by Tamm and Schubin in their pioneering development of a quantum-mechanical theory of photoeffect in 1931. In accordance with our calculations, this possible predominance of the surface effect is based on two factors: (i) effective cooling of hot carriers during their propagation from the volume of the nanoparticle to its surface in the scenario of the volume mechanism and (ii) strengthening of the surface mechanism through the effect of the discontinuity of the dielectric permittivity at the nanoparticle boundary. The latter is stronger at relatively lower photon energies and correspondingly is more substantial for internal photoemission than for an external one. We show that in the general case, it is essential to take both mechanisms into account in the development of devices based on the photoelectric effect and when considering hot electron emission from a plasmonic nanoantenna.

  1. Comparison of protein synthesis and degradation in incubated and perfused muscle.

    PubMed Central

    Clark, A S; Mitch, W E

    1983-01-01

    Rates of muscle protein synthesis and degradation measured in the perfused hindquarter were compared with those in incubated epitrochlearis muscles. With fed or starved mature rats, results without insulin treatment were identical. With insulin treatment, protein synthesis in perfused hindquarters was greater, though protein degradation was the same. Thus rates of muscle protein degradation estimated by these two methods in vitro correspond closely. PMID:6349623

  2. A comparison of optimisation methods and knee joint degrees of freedom on muscle force predictions during single-leg hop landings.

    PubMed

    Mokhtarzadeh, Hossein; Perraton, Luke; Fok, Laurence; Muñoz, Mario A; Clark, Ross; Pivonka, Peter; Bryant, Adam L

    2014-09-22

    The aim of this paper was to compare the effect of different optimisation methods and different knee joint degrees of freedom (DOF) on muscle force predictions during a single legged hop. Nineteen subjects performed single-legged hopping manoeuvres and subject-specific musculoskeletal models were developed to predict muscle forces during the movement. Muscle forces were predicted using static optimisation (SO) and computed muscle control (CMC) methods using either 1 or 3 DOF knee joint models. All sagittal and transverse plane joint angles calculated using inverse kinematics or CMC in a 1 DOF or 3 DOF knee were well-matched (RMS error<3°). Biarticular muscles (hamstrings, rectus femoris and gastrocnemius) showed more differences in muscle force profiles when comparing between the different muscle prediction approaches where these muscles showed larger time delays for many of the comparisons. The muscle force magnitudes of vasti, gluteus maximus and gluteus medius were not greatly influenced by the choice of muscle force prediction method with low normalised root mean squared errors (<48%) observed in most comparisons. We conclude that SO and CMC can be used to predict lower-limb muscle co-contraction during hopping movements. However, care must be taken in interpreting the magnitude of force predicted in the biarticular muscles and the soleus, especially when using a 1 DOF knee. Despite this limitation, given that SO is a more robust and computationally efficient method for predicting muscle forces than CMC, we suggest that SO can be used in conjunction with musculoskeletal models that have a 1 or 3 DOF knee joint to study the relative differences and the role of muscles during hopping activities in future studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Comparison of contraction times of a muscle and its motor units

    NASA Technical Reports Server (NTRS)

    Eldred, E.; Smith, L.; Edgerton, V. R.

    1992-01-01

    The twitch contraction time (CT) for each of 13 soleus (SOL) and 13 medial gastrocnemius (MG) muscles was compared with the mean CT from a sample of its motor units (MUs; 356 total) to see if the CT of a whole muscle when tested at its optimal length (Lo) differed systematically from that of its MUs tested at their individual Lo's. The CTs of the whole muscle were significantly longer in the ratio of 1.13. This is consistent with a hypothesis that electrical-field effects result in a more protracted contraction of the individual muscle fiber.

  4. Sex Assessment from the Volume of the First Metatarsal Bone: A Comparison of Linear and Volume Measurements.

    PubMed

    Gibelli, Daniele; Poppa, Pasquale; Cummaudo, Marco; Mattia, Mirko; Cappella, Annalisa; Mazzarelli, Debora; Zago, Matteo; Sforza, Chiarella; Cattaneo, Cristina

    2017-02-23

    Sexual dimorphism is a crucial characteristic of skeleton. In the last years, volumetric and surface 3D acquisition systems have enabled anthropologists to assess surfaces and volumes, whose potential still needs to be verified. This article aimed at assessing volume and linear parameters of the first metatarsal bone through 3D acquisition by laser scanning. Sixty-eight skeletons underwent 3D scan through laser scanner: Seven linear measurements and volume from each bone were assessed. A cutoff value of 13,370 mm(3) was found, with an accuracy of 80.8%. Linear measurements outperformed volume: metatarsal length and mediolateral width of base showed higher cross-validated accuracies (respectively, 82.1% and 79.1%, raising at 83.6% when both of them were included). Further studies are needed to verify the real advantage for sex assessment provided by volume measurements. © 2017 American Academy of Forensic Sciences.

  5. The reliability of ultrasonographic measurements for testicular volume assessment: comparison of three common formulas with true testicular volume.

    PubMed

    Hsieh, Ming-Li; Huang, Shih-Tsung; Huang, Hsin-Chieh; Chen, Yu; Hsu, Yu-Chao

    2009-03-01

    The aim of this study was to determine the correlation of ultrasonographic estimates of testicular volume with true testicular volume and to compare the accuracy and precision of the three most commonly utilized formulas. A total of 15 patients underwent high-resolution ultrasonography (US) analysis for testicular volume before orchiectomy. Testicular volume was calculated using three common formulas: (1) length (L) x width (W) x height (H) x 0.52; (2) the empirical formula of Lambert: L x W x H x 0.71; and (3) L x W2 x 0.52. The actual volume of each removed testis was estimated directly by a water displacement method. Thus, four volume measurements were obtained for each of the 30 testes. The obtained data were analyzed by paired t-test and linear regression analysis. All three US formula measurements significantly underestimated the true testicular volume. The largest mean biases were observed with US formula 1, which underestimated the true volume by 3.3 mL (31%). US formula 2 had a smaller mean difference from the true volume, with an underestimation of only 0.6 mL (6%). Regression analysis showed that formulas 1 and 2 had better R2 values than formula 3. However, all three US formulas displayed a strong linear relationship with the true volume (R2= 0.872-0.977; P < 0.001). Among the commonly used US formulas, the empirical formula of Lambert (L x W x H x 0.71) provided better accuracy than the other two formulas evaluated, and better precision than formula 3. Therefore, the formula of Lambert is the optimal choice in clinical practice.

  6. The reliability of ultrasonographic measurements for testicular volume assessment: comparison of three common formulas with true testicular volume

    PubMed Central

    Hsieh, Ming-Li; Huang, Shih-Tsung; Huang, Hsin-Chieh; Chen, Yu; Hsu, Yu-Chao

    2009-01-01

    The aim of this study was to determine the correlation of ultrasonographic estimates of testicular volume with true testicular volume and to compare the accuracy and precision of the three most commonly utilized formulas. A total of 15 patients underwent high-resolution ultrasonography (US) analysis for testicular volume before orchiectomy. Testicular volume was calculated using three common formulas: (1) length (L) × width (W) × height (H) × 0.52; (2) the empirical formula of Lambert: L × W × H × 0.71; and (3) L × W2 × 0.52. The actual volume of each removed testis was estimated directly by a water displacement method. Thus, four volume measurements were obtained for each of the 30 testes. The obtained data were analyzed by paired t-test and linear regression analysis. All three US formula measurements significantly underestimated the true testicular volume. The largest mean biases were observed with US formula 1, which underestimated the true volume by 3.3 mL (31%). US formula 2 had a smaller mean difference from the true volume, with an underestimation of only 0.6 mL (6%). Regression analysis showed that formulas 1 and 2 had better R2 values than formula 3. However, all three US formulas displayed a strong linear relationship with the true volume (R2= 0.872−0.977; P < 0.001). Among the commonly used US formulas, the empirical formula of Lambert (L × W × H × 0.71) provided better accuracy than the other two formulas evaluated, and better precision than formula 3. Therefore, the formula of Lambert is the optimal choice in clinical practice. PMID:19151736

  7. Comparison of brain volume abnormalities between ADHD and conduct disorder in adolescence.

    PubMed

    Stevens, Michael C; Haney-Caron, Emily

    2012-11-01

    Previous studies of brain structure abnormalities in conduct disorder and attention-deficit/hyperactivity disorder (ADHD) samples have been limited owing to cross-comorbidity, preventing clear understanding of which structural brain abnormalities might be specific to or shared by each disorder. To our knowledge, this study was the first direct comparison of grey and white matter volumes in diagnostically "pure" (i.e., no comorbidities) conduct disorder and ADHD samples. Groups of adolescents with noncormobid conduct disorder and with noncomorbid, combined-subtype ADHD were compared with age- and sex-matched controls using DARTEL voxel-based analysis of T1-weighted brain structure images. Analysis of variance with post hoc analyses compared whole brain grey and white matter volumes among the groups. We included 24 adolescents in each study group. There was an overall 13% reduction in grey matter volume in adolescents with conduct disorder, reflecting numerous frontal, temporal, parietal and subcortical deficits. The same grey matter regions typically were not abnormal in those with ADHD. Deficits in frontal lobe regions previously identified in studies of patients with ADHD either were not detected, or group differences from controls were not as strong as those between the conduct disorder and control groups. White matter volume measurements did not differentiate conduct disorder and ADHD. Our modest sample sizes prevented meaningful examination of individual features of ADHD or conduct disorder, such as aggression, callousness, or hyperactive versus inattentive symptom subtypes. The evidence supports theories of frontotemporal abnormalities in adolescents with conduct disorder, but raises questions about the prominence of frontal lobe and striatal structural abnormalities in those with noncomorbid, combined-subtype ADHD. The latter point is clinically important, given the widely held belief that ADHD is associated with numerous frontal lobe structural deficits, a

  8. Comparison of brain volume abnormalities between ADHD and conduct disorder in adolescence

    PubMed Central

    Stevens, Michael C.; Haney-Caron, Emily

    2012-01-01

    Background Previous studies of brain structure abnormalities in conduct disorder and attention-deficit/hyperactivity disorder (ADHD) samples have been limited owing to cross-comorbidity, preventing clear understanding of which structural brain abnormalities might be specific to or shared by each disorder. To our knowledge, this study was the first direct comparison of grey and white matter volumes in diagnostically “pure” (i.e., no comorbidities) conduct disorder and ADHD samples. Methods Groups of adolescents with noncormobid conduct disorder and with noncomorbid, combined-subtype ADHD were compared with age- and sex-matched controls using DARTEL voxel-based analysis of T1-weighted brain structure images. Analysis of variance with post hoc analyses compared whole brain grey and white matter volumes among the groups. Results We included 24 adolescents in each study group. There was an overall 13% reduction in grey matter volume in adolescents with conduct disorder, reflecting numerous frontal, temporal, parietal and subcortical deficits. The same grey matter regions typically were not abnormal in those with ADHD. Deficits in frontal lobe regions previously identified in studies of patients with ADHD either were not detected, or group differences from controls were not as strong as those between the conduct disorder and control groups. White matter volume measurements did not differentiate conduct disorder and ADHD. Limitations Our modest sample sizes prevented meaningful examination of individual features of ADHD or conduct disorder, such as aggression, callousness, or hyperactive versus inattentive symptom subtypes. Conclusion The evidence supports theories of frontotemporal abnormalities in adolescents with conduct disorder, but raises questions about the prominence of frontal lobe and striatal structural abnormalities in those with noncomorbid, combined-subtype ADHD. The latter point is clinically important, given the widely held belief that ADHD is

  9. A comparison of peripheral imaging technologies for bone and muscle quantification: a technical review of image acquisition.

    PubMed

    Wong, A K

    2016-12-14

    The choice of an appropriate imaging technique to quantify bone, muscle, or muscle adiposity needs to be guided by a thorough understanding of its competitive advantages over other modalities balanced by its limitations. This review details the technical machinery and methods behind peripheral quantitative computed tomography (pQCT), high-resolution (HR)-pQCT, and magnetic resonance imaging (MRI) that drive successful depiction of bone and muscle morphometry, densitometry, and structure. It discusses a number of image acquisition settings, the challenges associated with using one versus another, and compares the risk-benefits across the different modalities. Issues related to all modalities including partial volume artifact, beam hardening, calibration, and motion assessment are also detailed. The review further provides data and images to illustrate differences between methods to better guide the reader in selecting an imaging method strategically. Overall, investigators should be cautious of the impact of imaging parameters on image signal or contrast-to-noise-ratios, and the need to report these settings in future publications. The effect of motion should be assessed on images and a decision made to exclude prior to segmentation. A more standardized approach to imaging bone and muscle on pQCT and MRI could enhance comparability across studies and could improve the quality of meta-analyses.

  10. A comparison of peripheral imaging technologies for bone and muscle quantification: a technical review of image acquisition

    PubMed Central

    Wong, A.K.O.

    2016-01-01

    The choice of an appropriate imaging technique to quantify bone, muscle, or muscle adiposity needs to be guided by a thorough understanding of its competitive advantages over other modalities balanced by its limitations. This review details the technical machinery and methods behind peripheral quantitative computed tomography (pQCT), high-resolution (HR)-pQCT, and magnetic resonance imaging (MRI) that drive successful depiction of bone and muscle morphometry, densitometry, and structure. It discusses a number of image acquisition settings, the challenges associated with using one versus another, and compares the risk-benefits across the different modalities. Issues related to all modalities including partial volume artifact, beam hardening, calibration, and motion assessment are also detailed. The review further provides data and images to illustrate differences between methods to better guide the reader in selecting an imaging method strategically. Overall, investigators should be cautious of the impact of imaging parameters on image signal or contrast-to-noise-ratios, and the need to report these settings in future publications. The effect of motion should be assessed on images and a decision made to exclude prior to segmentation. A more standardized approach to imaging bone and muscle on pQCT and MRI could enhance comparability across studies and could improve the quality of meta-analyses. PMID:27973379

  11. Comparison of muscle synergies for running between different foot strike patterns

    PubMed Central

    Nishida, Koji; Hagio, Shota; Kibushi, Benio; Moritani, Toshio; Kouzaki, Motoki

    2017-01-01

    It is well known that humans run with a fore-foot strike (FFS), a mid-foot strike (MFS) or a rear-foot strike (RFS). A modular neural control mechanism of human walking and running has been discussed in terms of muscle synergies. However, the neural control mechanisms for different foot strike patterns during running have been overlooked even though kinetic and kinematic differences between different foot strike patterns have been reported. Thus, we examined the differences in the neural control mechanisms of human running between FFS and RFS by comparing the muscle synergies extracted from each foot strike pattern during running. Muscle synergies were extracted using non-negative matrix factorization with electromyogram activity recorded bilaterally from 12 limb and trunk muscles in ten male subjects during FFS and RFS running at different speeds (5–15 km/h). Six muscle synergies were extracted from all conditions, and each synergy had a specific function and a single main peak of activity in a cycle. The six muscle synergies were similar between FFS and RFS as well as across subjects and speeds. However, some muscle weightings showed significant differences between FFS and RFS, especially the weightings of the tibialis anterior of the landing leg in synergies activated just before touchdown. The activation patterns of the synergies were also different for each foot strike pattern in terms of the timing, duration, and magnitude of the main peak of activity. These results suggest that the central nervous system controls running by sending a sequence of signals to six muscle synergies. Furthermore, a change in the foot strike pattern is accomplished by modulating the timing, duration and magnitude of the muscle synergy activity and by selectively activating other muscle synergies or subsets of the muscle synergies. PMID:28158258

  12. Comparison of muscle synergies for running between different foot strike patterns.

    PubMed

    Nishida, Koji; Hagio, Shota; Kibushi, Benio; Moritani, Toshio; Kouzaki, Motoki

    2017-01-01

    It is well known that humans run with a fore-foot strike (FFS), a mid-foot strike (MFS) or a rear-foot strike (RFS). A modular neural control mechanism of human walking and running has been discussed in terms of muscle synergies. However, the neural control mechanisms for different foot strike patterns during running have been overlooked even though kinetic and kinematic differences between different foot strike patterns have been reported. Thus, we examined the differences in the neural control mechanisms of human running between FFS and RFS by comparing the muscle synergies extracted from each foot strike pattern during running. Muscle synergies were extracted using non-negative matrix factorization with electromyogram activity recorded bilaterally from 12 limb and trunk muscles in ten male subjects during FFS and RFS running at different speeds (5-15 km/h). Six muscle synergies were extracted from all conditions, and each synergy had a specific function and a single main peak of activity in a cycle. The six muscle synergies were similar between FFS and RFS as well as across subjects and speeds. However, some muscle weightings showed significant differences between FFS and RFS, especially the weightings of the tibialis anterior of the landing leg in synergies activated just before touchdown. The activation patterns of the synergies were also different for each foot strike pattern in terms of the timing, duration, and magnitude of the main peak of activity. These results suggest that the central nervous system controls running by sending a sequence of signals to six muscle synergies. Furthermore, a change in the foot strike pattern is accomplished by modulating the timing, duration and magnitude of the muscle synergy activity and by selectively activating other muscle synergies or subsets of the muscle synergies.

  13. Comparison of temporal muscle fascia and cartilage grafts in pediatric tympanoplasties.

    PubMed

    Demirci, Sule; Tuzuner, Arzu; Karadas, Hatice; Acıkgoz, Cemile; Caylan, Refik; Samim, Ethem Erdal

    2014-01-01

    To compare anatomic and functional outcomes of the different graft materials used in pediatric tympanoplasty. The patients younger than 18 years of age and who had tympanoplasty between 2010 and 2012 were included in the study. Temporal muscle fascia or cartilage was used as the graft material. The age, gender, the side of the operated ear, the operation technique, pre- and postoperative audiological results, and the status of the graft were noted. An intact graft and an air-bone gap (ABG) ≤ 20 were regarded as surgical success in the postoperative period. Audiograms obtained before surgery and 1 year after surgery were used for the comparison. Sixty pediatric cases were included in the study. Fascia graft was used as the graft material in 35 of them, and cartilage was used in 25 patients. The graft success rate was 82.9% in the fascia group while it was 92% in the cartilage group. In the fascia group preoperative ABG was 28.2 ± 10.1 dB, postoperative ABG was 15.1 ± 10.2dB, and postoperative gain was 13.1 ± 9.6 dB. In the cartilage group, preoperative ABG was 28.9 ± 10.2dB, and postoperative ABG was 16.8 ± 10.3 dB with a postoperative gain of 12.1 ± 6.8 dB. The differences between the fascia and the cartilage groups were not statistically significant either for hearing gain or graft success rate. Cartilage and fascia grafts yield similar results for hearing gain and graft success rate in pediatric tympanoplasty. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Effect of short-term equal-volume resistance training with different workout frequency on muscle mass and strength in untrained men and women.

    PubMed

    Candow, Darren G; Burke, Darren G

    2007-02-01

    Changes in muscle mass and strength will vary, depending on the volume and frequency of training. The purpose of this study was to determine the effect of short-term equal-volume resistance training with different workout frequency on lean tissue mass and muscle strength. Twenty-nine untrained volunteers (27-58 years; 23 women, 6 men) were assigned randomly to 1 of 2 groups: group 1 (n = 15; 12 women, 3 men) trained 2 times per week and performed 3 sets of 10 repetitions to fatigue for 9 exercises, group 2 (n = 14; 11 women, 3 men) trained 3 times per week and performed 2 sets of 10 repetitions to fatigue for 9 exercises. Prior to and following training, whole-body lean tissue mass (dual energy x-ray absorptiometry) and strength (1 repetition maximum squat and bench press) were measured. Both groups increased lean tissue mass (2.2%), squat strength (28%), and bench press strength (22-30%) with training (p < 0.05), with no other differences. These results suggest that the volume of resistance training may be more important than frequency in developing muscle mass and strength in men and women initiating a resistance training program.

  15. Comparison of glucose-transporter-containing vesicles from rat fat and muscle tissues: evidence for a unique endosomal compartment.

    PubMed Central

    Kandror, K V; Coderre, L; Pushkin, A V; Pilch, P F

    1995-01-01

    Insulin-sensitive tissues (fat and muscle) express a specific isoform of glucose-transporter protein, GLUT4, which normally resides in intracellular vesicular structures and is translocated to the cell surface in response to insulin. Here we provide a biochemical comparison of GLUT4-containing structures from fat and muscle cells. We demonstrate that, in spite of totally different protocols for cell homogenization and fractionation used for adipocytes as compared with skeletal-muscle tissue, GLUT4-containing vesicles from both sources have identical buoyant densities, sedimentation coefficients, and a very similar, if not identical, protein composition. The individual proteins first identified in GLUT4-containing vesicles from adipocytes (GTV3/SCAMPs proteins and aminopeptidase gp160) are also present in the analogous vesicles from muscle. Intracellular microsomes from rat adipocytes also contain GLUT1, a ubiquitously expressed glucose-transporter isoform. GLUT1 has not been detected in intracellular vesicular pool(s) from skeletal-muscle cells, probably because of its low abundance there. GLUT1 in adipocytes is excluded from GLUT4-containing vesicles, but is found in membrane structures which are indistinguishable from the former by all methods tested and demonstrate the same type of regulation by insulin. That is, the GLUT1- and GLUT4-containing vesicles have identical densities and sedimentation coefficients in sucrose gradients, and translocate to the cell surface in response to hormonal exposure. Also, we describe a simple procedure for the purification of native glucose-transporter vesicles from rat adipocytes. Overall, our data suggest the existence of a unique endosomal compartment in fat and muscle cells which is functionally and compositionally different from other microsomal vesicles and which is responsible for insulin-sensitive glucose transport in these tissues. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9

  16. SU-E-I-84: Accuracy Comparison of Multi-Modality Image-Based Volumes of Rodent Solid Tumors Using In-Air Micro-CT Image Volume

    SciTech Connect

    Lee, Y; Fullerton, G; Goins, B

    2015-06-15

    Purpose: Tumor volume is considered as a better predictor for therapy response monitoring and tumor staging over Response Evaluation Criteria In Solid Tumors (RECIST) or World Health Organization (WHO) criteria. In this study, the accuracy of subcutaneous rodent tumor volumes using preclinical magnetic resonance imaging (MRI), micro-computed tomography (micro-CT) and ultrasound (US) equipment and with an external caliper was compared using in-air micro-CT image volume of excised tumors determined as reference tumor volume in our prior study. Methods: MR, US and micro-CT images of subcutaneous SCC4 head and neck tumor xenografts were acquired 4, 6, 9, 11 and 13 days after tumor cell inoculation. Before MR and US scans, caliper measurements were made. After tumors were excised, in-air micro-CT imaging and ex vivo caliper measurements were performed. Tumor volumes were calculated using formula V = (π/6)*a*b*c where a, b and c are the maximum diameters in three perpendicular dimensions determined by the three image modalities and caliper, and compared with reference tumor volume by linear regression analysis as well as Bland-Altman plots. A one-way Analysis of Variance (ANOVA) test was also performed to compare volumes among caliper measurements. Results: The correlation coefficients (R2) of the regression lines for tumor volumes measured by the three imaging modalities and caliper were 0.9939, 0.9669, 0.9806, 0.9274, 0.9619 and 0.9819 for MRI, US and micro-CT, caliperbeforeMRI, caliperbeforeUS and ex vivo caliper respectively. In Bland-Altman plots, the average of tumor volume difference from reference tumor volume (bias) was significant for caliper and micro- CT, but not for MRI and US. Comparison of caliper measurements showed a significant difference (p < 0.05). Conclusion: Using the in-air micro-CT image volume, tumor volume measured by MRI was the most accurate among the three imaging modalities. In vivo caliper volume measurements showed unreliability while ex

  17. Fatty Infiltration of Skeletal Muscle: Mechanisms and Comparisons with Bone Marrow Adiposity.

    PubMed

    Hamrick, Mark W; McGee-Lawrence, Meghan E; Frechette, Danielle M

    2016-01-01

    Skeletal muscle and bone share common embryological origins from mesodermal cell populations and also display common growth trajectories early in life. Moreover, muscle and bone are both mechanoresponsive tissues, and the mass and strength of both tissues decline with age. The decline in muscle and bone strength that occurs with aging is accompanied in both cases by an accumulation of adipose tissue. In bone, adipocyte (AC) accumulation occurs in the marrow cavities of long bones and is known to increase with estrogen deficiency, mechanical unloading, and exposure to glucocorticoids. The factors leading to accumulation of intra- and intermuscular fat (myosteatosis) are less well understood, but recent evidence indicates that increases in intramuscular fat are associated with disuse, altered leptin signaling, sex steroid deficiency, and glucocorticoid treatment, factors that are also implicated in bone marrow adipogenesis. Importantly, accumulation of ACs in skeletal muscle and accumulation of intramyocellular lipid are linked to loss of muscle strength, reduced insulin sensitivity, and increased mortality among the elderly. Resistance exercise and whole body vibration can prevent fatty infiltration in skeletal muscle and also improve muscle strength. Therapeutic strategies to prevent myosteatosis may improve muscle function and reduce fall risk in the elderly, potentially impacting the incidence of bone fracture.

  18. Comparison of muscles activity of abled bodied and amputee subjects for around shoulder movement.

    PubMed

    Kaur, Amanpreet; Agarwal, Ravinder; Kumar, Amod

    2016-05-12

    Worldwide, about 56% of the amputees are upper limb amputees. This research deals a method with two-channel surface electromyogram (SEMG) signal recorded from around shoulder to estimate the changes in muscle activity in non-amputee and the residual limb of trans humeral amputees with different movements of arm. Identification of different muscles activity of near shoulder amputee and non-amputee persons. SEMG signal were acquired during three distinct exercises from three-selected muscles location around shoulder. The participants were asked to move their dominant arm from an assigned position to record their muscles activity recorded with change in position. Results shows the muscles activity in scalene is more than the other muscles like pectoralis and infraspinatus with the same shoulder motion. In addition, STFT (Short-Time Fourier Transform) spectrogram with window length of 256 samples at maximum of 512 frequency bins using hamming window has used to identify the signal for the maximum muscles activity with best resolution in spectrum plot. The results suggest that one can use this analysis for making a suitable device for around shoulder prosthetic users based on muscles activation of amputee persons.

  19. Early Site Permit Demonstration Program, plant parameters envelopes: Comparison with ranges of values for four hypothetical sites. Volume 2

    SciTech Connect

    Not Available

    1992-09-01

    The purpose of this volume is to report the results of the comparison of the ALWR plan parameters envelope with values of site characteristics developed for our hypothetical sites that generally represent conditions encountered within the United States. This effort is not intended to identify or address the suitability of any existing site, site area, or region in the United States. Also included in this volume is Appendix F, SERCH Summaries Regarding Siting.

  20. Comparison of rotator cuff muscle architecture between humans and other selected vertebrate species

    PubMed Central

    Mathewson, Margie A.; Kwan, Alan; Eng, Carolyn M.; Lieber, Richard L.; Ward, Samuel R.

    2014-01-01

    In this study, we compare rotator cuff muscle architecture of typically used animal models with that of humans and quantify the scaling relationships of these muscles across mammals. The four muscles that correspond to the human rotator cuff – supraspinatus, infraspinatus, subscapularis and teres minor – of 10 commonly studied animals were excised and subjected to a series of comparative measurements. When body mass among animals was regressed against physiological cross-sectional area, muscle mass and normalized fiber length, the confidence intervals suggested geometric scaling but did not exclude other scaling relationships. Based on the architectural difference index (ADI), a combined measure of fiber length-to-moment arm ratio, fiber length-to-muscle length ratio and the fraction of the total rotator cuff physiological cross-sectional area contributed by each muscle, chimpanzees were found to be the most similar to humans (ADI=2.15), followed closely by capuchins (ADI=2.16). Interestingly, of the eight non-primates studied, smaller mammals such as mice, rats and dogs were more similar to humans in architectural parameters compared with larger mammals such as sheep, pigs or cows. The force production versus velocity trade-off (indicated by fiber length-to-moment arm ratio) and the excursion ability (indicated by fiber length-to-muscle length ratio) of humans were also most similar to those of primates, followed by the small mammals. Overall, primates provide the best architectural representation of human muscle architecture. However, based on the muscle architectural parameters of non-primates, smaller rather than larger mammals may be better models for studying muscles related to the human rotator cuff. PMID:24072803

  1. Comparison of rotator cuff muscle architecture between humans and other selected vertebrate species.

    PubMed

    Mathewson, Margie A; Kwan, Alan; Eng, Carolyn M; Lieber, Richard L; Ward, Samuel R

    2014-01-15

    In this study, we compare rotator cuff muscle architecture of typically used animal models with that of humans and quantify the scaling relationships of these muscles across mammals. The four muscles that correspond to the human rotator cuff - supraspinatus, infraspinatus, subscapularis and teres minor - of 10 commonly studied animals were excised and subjected to a series of comparative measurements. When body mass among animals was regressed against physiological cross-sectional area, muscle mass and normalized fiber length, the confidence intervals suggested geometric scaling but did not exclude other scaling relationships. Based on the architectural difference index (ADI), a combined measure of fiber length-to-moment arm ratio, fiber length-to-muscle length ratio and the fraction of the total rotator cuff physiological cross-sectional area contributed by each muscle, chimpanzees were found to be the most similar to humans (ADI=2.15), followed closely by capuchins (ADI=2.16). Interestingly, of the eight non-primates studied, smaller mammals such as mice, rats and dogs were more similar to humans in architectural parameters compared with larger mammals such as sheep, pigs or cows. The force production versus velocity trade-off (indicated by fiber length-to-moment arm ratio) and the excursion ability (indicated by fiber length-to-muscle length ratio) of humans were also most similar to those of primates, followed by the small mammals. Overall, primates provide the best architectural representation of human muscle architecture. However, based on the muscle architectural parameters of non-primates, smaller rather than larger mammals may be better models for studying muscles related to the human rotator cuff.

  2. Comparison of algorithms to quantify muscle fatigue in upper limb muscles based on sEMG signals.

    PubMed

    Kahl, Lorenz; Hofmann, Ulrich G

    2016-11-01

    This work compared the performance of six different fatigue detection algorithms quantifying muscle fatigue based on electromyographic signals. Surface electromyography (sEMG) was obtained by an experiment from upper arm contractions at three different load levels from twelve volunteers. Fatigue detection algorithms mean frequency (MNF), spectral moments ratio (SMR), the wavelet method WIRM1551, sample entropy (SampEn), fuzzy approximate entropy (fApEn) and recurrence quantification analysis (RQA%DET) were calculated. The resulting fatigue signals were compared considering the disturbances incorporated in fatiguing situations as well as according to the possibility to differentiate the load levels based on the fatigue signals. Furthermore we investigated the influence of the electrode locations on the fatigue detection quality and whether an optimized channel set is reasonable. The results of the MNF, SMR, WIRM1551 and fApEn algorithms fell close together. Due to the small amount of subjects in this study significant differences could not be found. In terms of disturbances the SMR algorithm showed a slight tendency to out-perform the others.

  3. Comparison of immediate complete denture, tooth and implant-supported overdenture on vertical dimension and muscle activity

    PubMed Central

    Shah, Farhan Khalid; Gebreel, Ashraf; Elshokouki, Ali hamed; Habib, Ahmed Ali

    2012-01-01

    PURPOSE To compare the changes in the occlusal vertical dimension, activity of masseter muscles and biting force after insertion of immediate denture constructed with conventional, tooth-supported and Implant-supported immediate mandibular complete denture. MATERIALS AND METHODS Patients were selected and treatment was carried out with all the three different concepts i.e, immediate denture constructed with conventional (Group A), tooth-supported (Group B) and Implant-supported (Group C) immediate mandibular complete dentures. Parameters of evaluation and comparison were occlusal vertical dimension measured by radiograph (at three different time intervals), Masseter muscle electromyographic (EMG) measurement by EMG analysis (at three different positions of jaws) and bite force measured by force transducer (at two different time intervals). The obtained data were statistically analyzed by using ANOVA-F test at 5% level of significance. If the F test was significant, Least Significant Difference test was performed to test further significant differences between variables. RESULTS Comparison between mean differences in occlusal vertical dimension for tested groups showed that it was only statistically significant at 1 year after immediate dentures insertion. Comparison between mean differences in wavelet packet coefficients of the electromyographic signals of masseter muscles for tested groups was not significant at rest position, but significant at initial contact position and maximum voluntary clench position. Comparison between mean differences in maximum biting force for tested groups was not statistically significant at 5% level of significance. CONCLUSION Immediate complete overdentures whether tooth or implant supported prosthesis is recommended than totally mucosal supported prosthesis. PMID:22737309

  4. Comparison and analysis of Wuding and avian chicken skeletal muscle satellite cells.

    PubMed

    Tong, H Q; Jiang, Z Q; Dou, T F; Li, Q H; Xu, Z Q; Liu, L X; Gu, D H; Rong, H; Huang, Y; Chen, X B; Jois, M; Te Pas, M F W; Ge, C R; Jia, J J

    2016-10-05

    Chicken skeletal muscle satellite cells are located between the basement membrane and the sarcolemma of mature muscle fibers. Avian broilers have been genetically selected based on their high growth velocity and large muscle mass. The Wuding chicken is a famous local chicken in Yunnan Province that undergoes non-selection breeding and is slow growing. In this study, we aimed to explore differences in the proliferation and differentiation properties of satellite cells isolated from the two chicken breeds. Using immunofluorescence, hematoxylin-eosin staining and real-time polymerase chain reaction analysis, we analyzed the in vitro characteristics of proliferating and differentiating satellite cells isolated from the two chicken breeds. The growth curve of satellite cells was S-shaped, and cells from Wuding chickens entered the logarithmic phase and plateau phase 1 day later than those from Avian chicken. The results also showed that the two skeletal muscle satellite cell lines were positive for Pax7, MyoD and IGF-1. The expression of Pax7 followed a downward trend, whereas that of MyoD and IGF-1 first increased and subsequently decreased in cells isolated from the two chickens. These data indicated that the skeletal muscle satellite cells of Avian chicken grow and differentiate faster than did those of Wuding chickens. We suggest that the methods of breeding selection applied to these breeds regulate the characteristics of skeletal muscle satellite cells to influence muscle growth.

  5. Comparison of skeletal muscle strength between cardiac patients and age-matched healthy controls

    PubMed Central

    Baum, K.; Hildebrandt, U.; Edel, K.; Bertram, R.; Hahmann, H.; Bremer, F.J.; Böhmen, S.; Kammerlander, C.; Serafin, M.; Rüther, Th.; Miche, E.

    2009-01-01

    The purpose of the present study was to compare muscular strength of knee extensors and arm flexor muscles of cardiac patients (n = 638) and healthy controls (n = 961) in different age groups. Isometric torques were measured in a sitting position with the elbow, hip, and knee flexed to 900. For statistical analysis, age groups were pooled in decades from the age of 30 to 90 years. Additionally, the influence of physical lifestyle prior to disease on muscular strength was obtained in the patients. For statistical analysis three-way ANOVA (factors age, gender, and physical activity level) was used. Both in patients and in controls a significant age-dependent decline in maximal torque could be observed for arm flexors and knee extensors. Maximal leg extensor muscle showed statistically significant differences between healthy controls and cardiac patients as well as between subgroups of patients: Physically inactive patients showed lowest torques (male: 148 ± 18 Nm; female: 82 ± 25 Nm) while highest values were measured in control subjects (male: 167 ± 16 Nm; female: 93 ± 17 Nm). In contrast, arm flexor muscles did not show any significant influence of health status or sports history. This qualitative difference between weight-bearing leg muscles and the muscle group of the upper extremity suggest that lower skeletal muscle strength in heart patients is mainly a consequence of selective disuse of leg muscles rather than any pathological skeletal muscle metabolism. Since a certain level of skeletal muscle strength is a prerequisite to cope with everyday activities, strength training is recommended as an important part of cardiac rehabilitation. PMID:19584952

  6. Biomechanical comparison of different suturing techniques in rabbit medial gastrocnemius muscle laceration repair.

    PubMed

    He, Min; Sebastin, Sandeep J; Gan, Aaron W T; Lim, Aymeric Y T; Chong, Alphonsus K S

    2014-09-01

    Skeletal muscle laceration is a common injury. Repair of disrupted delicate tissue is still a clinical challenge for surgeons. A few different muscle repair techniques have been reported. However, the best muscle repair technique has not been identified. The aim of the present study is to compare the biomechanical features of different repair techniques in muscles to identify the most effective one. New Zealand white rabbits (2.5-3 kg) were euthanized and medial gastrocnemius muscles were isolated. The muscles were completely transected with scalpels and then repaired by 3 different techniques, namely, (1) 2-strand mattress, (2) 4-strand Kessler (with epitendinous suture), and (3) Mason-Allen. To measure suture performance, the repaired specimens were mounted onto a mechanical testing machine Instron 5543. The muscles were loaded to failure at a constant speed of 60 mm/min. Data collected from Merlin v5.31 software were used to compute the biomechanical properties of each specimen. There was no significant difference in the mean maximum load of Kessler group (15.5 N) and Mason-Allen group (13.2 N), whereas the mean maximum load of the control (Mattress) group (4.4 N) was significantly smaller than the other 2 groups. Moreover, Kessler stitches were the stiffest among the 3. It is noteworthy that the mechanisms of failure were different: Kessler stitches were all pulled out longitudinally, whereas Mason-Allen stitches transmitted load across the laceration and ruptures occur at areas adjacent to the stitches, indicating that muscle is the weakest element in the biomechanical testing. Both Kessler and Mason-Allen stitches have shown better biomechanical features compared with the control group. Further study has to be done to compare the effect of these 2 techniques on muscle regeneration and scar formation in an in vivo model.

  7. Muscle activation comparisons between elastic and isoinertial resistance: A meta-analysis.

    PubMed

    Aboodarda, Saied Jalal; Page, Phillip A; Behm, David George

    2016-11-01

    Elastic resistance has been commonly used in the therapeutic and fitness setting; however, the ability of elastic resistance to overload and activate muscles has been questioned because of linear increase in elastic resistance as the device is elongated. The purpose of this meta-analysis was to examine the available literature on muscle activation associated with isoinertial and elastic resistance exercises, and to provide a quantitative summary comparing the two resistance training modes. In a random-effects model, the Hedge's g effect size was used to calculate the biased corrected standardized mean difference between the elastic and isoinertial resistance activation of prime movers (agonist), antagonists, assistant movers and stabilizer muscles. There was a lack of significant difference with the prime movers (effect size=-0.037, confidence interval: -0.202 to 0.128, p=0.660), antagonists (effect size=0.089, confidence interval: -0.112 to 0.290, p=0.385), synergists (effect size=-0.133, confidence interval: -0.342 to 0.076, p=0.213) and stabilizer (effect size=0.142, confidence interval: -0.006 to 0.289, p=0.060) muscle electromyography activity recorded during similar exercises using elastic and isoinertial resistance. Elastic resistance provides similar prime mover, antagonist, assistant movers and stabilizer muscle activation as isoinertial resistance; contradicting the traditional criticism that the elastic band would not elicit comparable levels of muscle activation as isoinertial resistance exercise. Since development of muscle strength is closely related to the duration of muscle tension, relatively equal muscle adaptations could be expected following the two modes of training provided that equal external resistance is employed between the two exercises. 2a. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Architectural and morphological assessment of rat abdominal wall muscles: comparison for use as a human model

    PubMed Central

    Brown, Stephen H M; Banuelos, Karina; Ward, Samuel R; Lieber, Richard L

    2010-01-01

    The abdominal wall is a composite of muscles that are important for the mechanical stability of the spine and pelvis. Tremendous clinical attention is given to these muscles, yet little is known about how they function in isolation or how they interact with one another. Given the morphological, vascular, and innervation complexities associated with these muscles and their proximity to the internal organs, an appropriate animal model is important for understanding their physiological and mechanical significance during function. To determine the extent to which the rat abdominal wall resembles that of human, 10 adult male Sprague-Dawley rats were killed and formalin-fixed for architectural and morphological analyses of the four abdominal wall muscles (rectus abdominis, external oblique, internal oblique, and transversus abdominis). Physiological cross-sectional areas and optimal fascicle lengths demonstrated a pattern that was similar to human abdominal wall muscles. In addition, sarcomere lengths measured in the neutral spine posture were similar to human in their relation to optimal sarcomere length. These data indicate that the force-generating and length change capabilities of these muscles, relative to one another, are similar in rat and human. Finally, the fiber lines of action of each abdominal muscle were similar to human over most of the abdominal wall. The main exception was in the lower abdominal region (inferior to the pelvic crest), where the external oblique becomes aponeurotic in human but continues as muscle fibers into its pelvic insertion in the rat. We conclude that, based on the morphology and architecture of the abdominal wall muscles, the adult male Sprague-Dawley rat is a good candidate for a model representation of human, particularly in the middle and upper abdominal wall regions. PMID:20646108

  9. Architectural and morphological assessment of rat abdominal wall muscles: comparison for use as a human model.

    PubMed

    Brown, Stephen H M; Banuelos, Karina; Ward, Samuel R; Lieber, Richard L

    2010-09-01

    The abdominal wall is a composite of muscles that are important for the mechanical stability of the spine and pelvis. Tremendous clinical attention is given to these muscles, yet little is known about how they function in isolation or how they interact with one another. Given the morphological, vascular, and innervation complexities associated with these muscles and their proximity to the internal organs, an appropriate animal model is important for understanding their physiological and mechanical significance during function. To determine the extent to which the rat abdominal wall resembles that of human, 10 adult male Sprague-Dawley rats were killed and formalin-fixed for architectural and morphological analyses of the four abdominal wall muscles (rectus abdominis, external oblique, internal oblique, and transversus abdominis). Physiological cross-sectional areas and optimal fascicle lengths demonstrated a pattern that was similar to human abdominal wall muscles. In addition, sarcomere lengths measured in the neutral spine posture were similar to human in their relation to optimal sarcomere length. These data indicate that the force-generating and length change capabilities of these muscles, relative to one another, are similar in rat and human. Finally, the fiber lines of action of each abdominal muscle were similar to human over most of the abdominal wall. The main exception was in the lower abdominal region (inferior to the pelvic crest), where the external oblique becomes aponeurotic in human but continues as muscle fibers into its pelvic insertion in the rat. We conclude that, based on the morphology and architecture of the abdominal wall muscles, the adult male Sprague-Dawley rat is a good candidate for a model representation of human, particularly in the middle and upper abdominal wall regions.

  10. Comparison of skeletal muscle strength between cardiac patients and age-matched healthy controls.

    PubMed

    Baum, K; Hildebrandt, U; Edel, K; Bertram, R; Hahmann, H; Bremer, F J; Böhmen, S; Kammerlander, C; Serafin, M; Rüther, Th; Miche, E

    2009-07-06

    The purpose of the present study was to compare muscular strength of knee extensors and arm flexor muscles of cardiac patients (n = 638) and healthy controls (n = 961) in different age groups. Isometric torques were measured in a sitting position with the elbow, hip, and knee flexed to 90(0). For statistical analysis, age groups were pooled in decades from the age of 30 to 90 years. Additionally, the influence of physical lifestyle prior to disease on muscular strength was obtained in the patients. For statistical analysis three-way ANOVA (factors age, gender, and physical activity level) was used.Both in patients and in controls a significant age-dependent decline in maximal torque could be observed for arm flexors and knee extensors. Maximal leg extensor muscle showed statistically significant differences between healthy controls and cardiac patients as well as between subgroups of patients: Physically inactive patients showed lowest torques (male: 148 +/- 18 Nm; female: 82 +/- 25 Nm) while highest values were measured in control subjects (male: 167 +/- 16 Nm; female: 93 +/- 17 Nm). In contrast, arm flexor muscles did not show any significant influence of health status or sports history.This qualitative difference between weight-bearing leg muscles and the muscle group of the upper extremity suggest that lower skeletal muscle strength in heart patients is mainly a consequence of selective disuse of leg muscles rather than any pathological skeletal muscle metabolism. Since a certain level of skeletal muscle strength is a prerequisite to cope with everyday activities, strength training is recommended as an important part of cardiac rehabilitation.

  11. 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.

  12. Effects of equal-volume resistance training performed one or two times a week in upper body muscle size and strength of untrained young men.

    PubMed

    Gentil, P; Fischer, B; Martorelli, A S; Lima, R M; Bottaro, M

    2015-03-01

    The purpose of the present study was to compare the effects of equal-volume resistance training (RT) performed once or twice a week on muscle mass and strength of the elbow flexors in untrained young men. Thirty men (23 ± 3 years) without previous resistance training experience were divided into two groups: Group 1 (G1) trained each muscle group only once a week and group 2 (G2) trained each muscle twice a week during 10 weeks. Baseline and 10 weeks post-test elbow flexors muscle thickness (MT) were measured using a B-Mode ultrasound. Peak torque (PT) was assessed by an isokinetic dynamometer before and after the training program. Elbow flexors MT increased significantly (P<0.05) from 31.70 ± 3.31 to 33.43 ± 3.46 mm in G1, and from 32.78 ± 4.03 to 35.09 ± 3.55 mm in G2. Elbow flexors PT also increased (P<0.05) from 50.77 ± 9.26 to 54.15 ± 10.79 N.m in G1, and from 48.99 ± 11.52 to 55.29 ± 10.24 N.m in G2. The results of ANOVA did not reveal group by time interactions for any variable, indicating no difference between groups for the changes in MT or PT. The results from the present study suggest that untrained men experience similar gains in muscle mass and strength with equal volume RT performed one or two days per week.

  13. Comparison of upper limb muscles behaviour for skilled and recreational archers using compound bow

    NASA Astrophysics Data System (ADS)

    Ariffin, Muhammad Shahimi; Rambely, Azmin Sham

    2017-04-01

    The purpose of this study was to investigate muscles activity during archery by carrying out an electromyography (EMG) experiment towards 12 muscles and six joints involving two types of subject (skilled and recreational). EMG is used to detect muscle signals during any particular activity. There were two types of data recorded which were maximum voluntary contraction (MVC) and archery activity. The skilled archer was found to produce 280 N of biceps brachii, 213.9 N of the deltoid, 123.4 N of trapezius forces compare to that of the recreational archer with 371.1 N, 164.9 N and 163.8 N, respectively for the draw arm during drawing phase. It is concluded that the recreational archer tends to a muscle fatigue phenomenon thus may contribute to possible serious injuries.

  14. Comparison between the changes in muscle oxygenation and blood lactate concentration in finswimmers during incremental exercise

    NASA Astrophysics Data System (ADS)

    Wang, Bangde; Tian, Qingping; Zhang, Zhongxing; Gong, Hui

    2009-08-01

    For the purpose of comparing the response in local skeletal muscle oxygenation and blood lactate concentration during incremental exercise, 8 female finswimmers were recruited to take an incremental exercise on a cycle ergometer. Muscle oxygenation in right vastus lateralis (VL) were monitored by continuous wave near infrared spectroscopy (CW NIRS), respiratory gas exchange and blood lactate concentration ([La]b) were simultaneously measured by a metabolic system and a portable blood lactate analyzer respectively. NIRS measurements showed a muscle oxygenation index inflection point (OIip), from which the muscle oxygenation started to decrease dramatically. Significant correlations have been found between OIip and blood lactate threshold identified at the lowest [La]b value which was >0.5 mmol/L lower than that obtained at the following workload. These results might suggest that the CW NIRS measurement could be applied to monitor lactate threshold noninvasively.

  15. Direct comparison of progenitor cells derived from adipose, muscle, and bone marrow from wild-type or craniosynostotic rabbits

    PubMed Central

    GM, Cooper; EL, Lensie; JJ, Cray; MR, Bykowski; GE, DeCesare; MA, Smalley; MP, Mooney; PG, Campbell; JE, Losee

    2010-01-01

    Background Reports have identified cells capable of osteogenic differentiation in bone marrow, muscle, and adipose tissues, but there are few direct comparisons of these different cell-types. Also, few have investigated the potential connection between a tissue-specific pathology and cells derived from seemingly unrelated tissues. Here, we compare cells isolated from wild-type rabbits or rabbits with nonsyndromic craniosynostosis, defined as the premature fusion of one or more of the cranial sutures. Methods Cells were derived from bone marrow, adipose, and muscle of 10 day-old wild-type rabbits (WT; n=17) or from age-matched rabbits with familial nonsyndromic craniosynostosis (CS; n=18). Cells were stimulated with bone morphogenetic protein 4 (BMP4) and alkaline phosphatase expression and cell proliferation were assessed. Results In WT rabbits, cells derived from muscle had more alkaline phosphatase activity than cells derived from either adipose or bone marrow. The cells derived from CS rabbit bone marrow and muscle were significantly more osteogenic than WT. Adipose-derived cells demonstrated no significant differences. While muscle-derived cells were most osteogenic in WT rabbits, bone marrow-derived cells were most osteogenic in CS rabbits. Conclusions Results suggest that cells from different tissues have different potentials for differentiation. Furthermore, cells derived from rabbits with craniosynostosis were different from wild-type derived cells. Interestingly, cells derived from the craniosynostotic rabbits were not uniformly more responsive compared with wild-type cells, suggesting that specific tissue-derived cells may react differently in individuals with craniosynostosis. PMID:20871482

  16. Serial temperature monitoring and comparison of rectal and muscle temperatures in immobilized free-ranging black rhinoceros (Diceros bicornis).

    PubMed

    vdB Morkel, Peter; Miller, Michele; Jago, Mark; Radcliffe, Robin W; du Preez, Pierre; Olea-Popelka, Francisco; Sefton, Jennifer; Taft, Arthur; Nydam, Daryl; Gleed, Robin D

    2012-03-01

    Control of body temperature is critical to a successful anesthetic outcome, particularly during field immobilization of wild animals. Hyperthermia associated with exertion can lead to serious and potentially life-threatening complications such as organ damage (including myopathy) and death. Methods for monitoring core body temperature must accurately reflect the physiologic status of the animal in order for interventions to be effective. The goal of this preliminary study was to compare serial rectal and muscle temperatures in field-immobilized black rhinoceros (Diceros bicornis) and evaluate a possible association. Twenty-four free-ranging black rhinoceros were immobilized between February and March of 2010 in Ethosha National Park, Namibia. Pairwise comparisons showed a correlation of 0.73 (95% CI; 0.70-0.75) between rectal and muscle temperature measurements. Results from a multivariable model indicate that muscle temperature readings were, on average, 0.46 degrees C (95% CI; 0.36-0.57 degrees C) higher than rectal temperatures while adjusting for repeated measurements on the same rhinoceros, effect of duration of immobilization, and effect of ambient temperature on rhinoceroses' temperature readings. As immobilization time increased, muscle and rectal temperature values within an individual rhinoceros tended to equilibrate. The overall temperatures decreased by an average of 0.00059 degrees C/min (95% CI; -0.0047 to -0.0035 degrees C/min; P = 0.779). As the ambient temperature at time of immobilization increased by 1 degree C, the average rhinoceros temperature increased by 0.09 degrees C (95% CI; 0.06-0.11 degrees C, P < 0.0001). Higher body temperature creates a potential for cellular damage leading to complications that include myopathy. Methods for monitoring rectal, muscle, and ambient temperatures should be incorporated into anesthetic monitoring protocols for large ungulates, particularly under field conditions.

  17. Determination of skeletal muscle perfusion using arterial spin labeling NMRI: validation by comparison with venous occlusion plethysmography.

    PubMed

    Raynaud, J S; Duteil, S; Vaughan, J T; Hennel, F; Wary, C; Leroy-Willig, A; Carlier, P G

    2001-08-01

    T(1)-based determination of perfusion was performed with the high temporal and spatial resolution that monitoring of exercise physiology requires. As no data were available on the validation of this approach in human muscles, T(1)-based NMRI of perfusion was compared to standard strain-gauge venous occlusion plethysmography performed simultaneously within a 4 T magnet. Two different situations were investigated in 21 healthy young volunteers: 1) a 5-min ischemia of the leg, or 2) a 2-3 min ischemic exercise consisting of a plantar flexion on an amagnetic ergometer. Leg perfusion was monitored over 5-15 min of the recovery phase, after the air-cuff arterial occlusion had been released. The interesting features of the sequence were the use of a saturation-recovery module for the introduction of a T(1) modulation and of single-shot spin echo for imaging. Spatial resolution was 1.7 x 2.0 mm and temporal resolution was 2 s. For data analysis, ROIs were traced on different muscles and perfusion was calculated from the differences in muscle signal intensity in successive images. To allow comparison with the global measurement of perfusion by plethysmography, the T(1)-based NMR measurements in exercising muscles were rescaled to the leg cross-section. The perfusion measurements obtained by plethysmography and NMRI were in close agreement with a correlation coefficient between 0.87 and 0.92. This indicates that pulsed arterial techniques provide determination of muscle perfusion not only with superior spatial and temporal resolution but also with exactitude.

  18. Ultrastructural and molecular biologic comparison of classical proprioceptors and palisade endings in sheep extraocular muscles

    PubMed Central

    RUNGALDIER, Stefanie; HEILIGENBRUNNER, Stefan; MAYER, Regina; HANEFL-KRIVANEK, Christiane; LIPOWEC, Marietta; STREICHER, Johannes; BLUMER, Roland

    2016-01-01

    Purpose To analyze and compare the structural and molecular features of classical proprioceptors like muscle spindles and Golgi tendon organs (GTOs) and putative proprioceptors (palisade endings) in sheep extraocular muscle (EOMs). Methods The EOMs of four sheep were analyzed. Frozen sections or whole mount preparations of the samples were immunohistochemically labeled and analyzed by confocal laser scanning microscopy. Triple labeling with different combinations of antibodies against neurofilament, synaptophysin and choline acetyltransferase (ChAT) as well as α-bungarotoxin and phalloidin was performed. Microscopic anatomy of the nerve end organs was analyzed by transmission electron microscopy. Results The microscopic anatomy demonstrated that muscle spindles and GTOs had a perineural capsule and palisade endings a connective tissue capsule. Sensory nerve terminals in muscle spindles and GTOs contained only few vesicles whereas palisade nerve terminals were full of clear vesicles. Likewise, motor terminals in the muscle spindles’ polar regions were full of clear vesicles. Immunohistochemistry showed that sensory nerve fibers as well as their sensory nerve terminals in muscle spindles and GTOs were ChAT-negative. Palisade endings were supplied by ChAT-positive nerve fibers and the palisade complexes including palisade nerve terminals were also ChAT-immunoreactive. Motor terminals in muscle spindles were ChAT and α-bungarotoxin -positive. Conclusions The present study demonstrated in sheep EOMs that palisade endings are innervated by cholinergic axons exhibiting characteristics typical for motoneurons whereas muscle spindles (except the polar regions) and GTOs are supplied by non-cholinergic axons. These results question whether palisade endings are candidates for proprioceptors in EOMs. PMID:19553627

  19. Computational tools for calculating alternative muscle force patterns during motion: a comparison of possible solutions.

    PubMed

    Martelli, Saulo; Calvetti, Daniela; Somersalo, Erkki; Viceconti, Marco; Taddei, Fulvia

    2013-08-09

    Comparing the available electromyography (EMG) and the related uncertainties with the space of muscle forces potentially driving the same motion can provide insights into understanding human motion in healthy and pathological neuromotor conditions. However, it is not clear how effective the available computational tools are in completely sample the possible muscle forces. In this study, we compared the effectiveness of Metabolica and the Null-Space algorithm at generating a comprehensive spectrum of possible muscle forces for a representative motion frame. The hip force peak during a selected walking trial was identified using a lower-limb musculoskeletal model. The joint moments, the muscle lever arms, and the muscle force constraints extracted from the model constituted the indeterminate equilibrium equation at the joints. Two spectra, each containing 200,000 muscle force samples, were calculated using Metabolica and the Null-Space algorithm. The full hip force range was calculated using optimization and compared with the hip force ranges derived from the Metabolica and the Null-Space spectra. The Metabolica spectrum spanned a much larger force range than the NS spectrum, reaching 811N difference for the gluteus maximus intermediate bundle. The Metabolica hip force range exhibited a 0.3-0.4 BW error on the upper and lower boundaries of the full hip force range (3.4-11.3 BW), whereas the full range was imposed in the NS spectrum. The results suggest that Metabolica is well suited for exhaustively sample the spectrum of possible muscle recruitment strategy. Future studies will investigate the muscle force range in healthy and pathological neuromotor conditions.

  20. Comparison of muscle hypertrophy following 6-month of continuous and periodic strength training.

    PubMed

    Ogasawara, Riki; Yasuda, Tomohiro; Ishii, Naokata; Abe, Takashi

    2013-04-01

    To compare the effects of a periodic resistance training (PTR) program with those of a continuous resistance training (CTR) program on muscle size and function, 14 young men were randomly divided into a CTR group and a PTR group. Both groups performed high-intensity bench press exercise training [75 % of one repetition maximum (1-RM); 3 sets of 10 reps] for 3 days per week. The CTR group trained continuously over a 24-week period, whereas the PTR group performed three cycles of 6-week training (or retraining), with 3-week detraining periods between training cycles. After an initial 6 weeks of training, increases in cross-sectional area (CSA) of the triceps brachii and pectoralis major muscles and maximum isometric voluntary contraction of the elbow extensors and 1-RM were similar between the two groups. In the CTR group, muscle CSA and strength gradually increased during the initial 6 weeks of training. However, the rate of increase in muscle CSA and 1-RM decreased gradually after that. In the PTR group, increase in muscle CSA and strength during the first 3-week detraining/6-week retraining cycle were similar to that in the CTR group during the corresponding period. However, increase in muscle CSA and strength during the second 3-week detraining/6-week retraining cycle were significantly higher in the PTR group than in the CTR group. Thus, overall improvements in muscle CSA and strength were similar between the groups. The results indicate that 3-week detraining/6-week retraining cycles result in muscle hypertrophy similar to that occurring with continuous resistance training after 24 weeks.

  1. Comparison of Muscle Activation during Dominant Hand Wrist Flexion when Writing

    PubMed Central

    Park, Soohee

    2014-01-01

    [Purpose] This study investigated the difference in muscle activation of the dominant upper extremity in right-handed and left-handed persons during writing. [Subjects] There were 36 subjects (16 left- handers/ 20 right- handers), and the study was conducted from 03/01/2012 to 30/3/2012. [Methods] Six electrodes were attached to the FCU (flexor carpi ulnaris), FCR (flexor carpi radialis), ECU (extensor carpi ulnaris), ECR (extensor carpi radialis), and both UT (upper trapezius) muscles. [Results] FCU muscle activation was 16.77±9.12% in left-handers and 10.29±4.13% (%MVIC) in right-handers. FCR muscle activation was 19.09±9.43% in left-handers and 10.64±5.03% in right-handers. In addition, the UT muscle activation on the writing hand side was 11.91±5.79% in left-handers and 1.66±1.19% in right-handers. [Conclusion] As a result of this study, it was discovered that left-handers used more wrist flexion in performance of the writing task with the dominant upper extremity than right-handers, and that the left-handers activated the wrist and shoulder muscles more than the right-handers. These results indicate a potential danger of musculoskeletal disease in left-hander. PMID:24409013

  2. Pubovisceralis Muscle Fiber Architecture Determination: Comparison Between Biomechanical Modeling and Diffusion Tensor Imaging.

    PubMed

    Brandão, Sofia; Parente, Marco; Silva, Elisabete; Da Roza, Thuane; Mascarenhas, Teresa; Leitão, João; Cunha, João; Natal Jorge, Renato; Nunes, Rita Gouveia

    2017-01-17

    Biomechanical analysis of pelvic floor dysfunction requires knowledge of certain biomechanical parameters, such as muscle fiber direction, in order to adequately model function. Magnetic resonance (MR) diffusion tensor imaging (DTI) provides an estimate of overall muscle fiber directionality based on the mathematical description of water diffusivity. This work aimed at evaluating the concurrence between pubovisceralis muscle fiber representations obtained from DTI, and the maximum principal stress lines obtained through the finite element method. Seven datasets from axial T2-weighted images were used to build numerical models, and muscle fiber orientation estimated from the DT images. The in-plane projections of the first eigenvector of both vector fields describing muscle fiber orientation were extracted and compared. The directional consistency was evaluated by calculating the angle between the normalized vectors for the entire muscle and also for the right and left insertions, middle portions, and anorectal area. The values varied between 28° ± 6 (right middle portion) and 34° ± 9 (anorectal area), and were higher than the angular precision of the DT estimates, evaluated using wild bootstrapping analysis. Angular dispersion ranged from 17° ± 4 (left middle portion) to 23° ± 5 (anorectal area). Further studies are needed to examine acceptability of these differences when integrating the vectors estimated from DTI in the numerical analysis.

  3. Comparison of Muscle Activation during Dominant Hand Wrist Flexion when Writing.

    PubMed

    Park, Soohee

    2013-12-01

    [Purpose] This study investigated the difference in muscle activation of the dominant upper extremity in right-handed and left-handed persons during writing. [Subjects] There were 36 subjects (16 left- handers/ 20 right- handers), and the study was conducted from 03/01/2012 to 30/3/2012. [Methods] Six electrodes were attached to the FCU (flexor carpi ulnaris), FCR (flexor carpi radialis), ECU (extensor carpi ulnaris), ECR (extensor carpi radialis), and both UT (upper trapezius) muscles. [Results] FCU muscle activation was 16.77±9.12% in left-handers and 10.29±4.13% (%MVIC) in right-handers. FCR muscle activation was 19.09±9.43% in left-handers and 10.64±5.03% in right-handers. In addition, the UT muscle activation on the writing hand side was 11.91±5.79% in left-handers and 1.66±1.19% in right-handers. [Conclusion] As a result of this study, it was discovered that left-handers used more wrist flexion in performance of the writing task with the dominant upper extremity than right-handers, and that the left-handers activated the wrist and shoulder muscles more than the right-handers. These results indicate a potential danger of musculoskeletal disease in left-hander.

  4. The relationship of leg volume (muscle plus bone) to maximal aerobic power output on a bicycle ergometer: the effects of anaemia, malnutrition and physical activity.

    PubMed

    Davies, C T

    1974-01-01

    The relationship of maximal power output (VO2 max) to leg muscle plus bone) volume (LV) has been analysed in African children suffering from malnutrition and severe anaemia and in a group of rural adult Africans engaged in prolonged, active daily work. The results are examined in relation to 'normal' healthy active (but not in training) African ? s and ? s aged 7-35 years. The analysis clearly demonstrates that the association between VO2 max and LV is not causal; the effects of increased habitual activity and anaemia show that the two parameters can be varied independently. The effect of habitual activity on the VO2 max : LV relationship is essentially additive, whereas the effect of anaemia is multiplicative. However in malnutrition, the relationship remains unchanged; VO2 max decreases paripassu with the reduced leg (muscle plus bone) volume. Iron therapy produces an increase in VO2 max) towards normal values without a concomitant change in LV. The results give a clearer understanding of the relationship between 'active' muscle mass and aerobic power output on the bicycle ergometer and could be used as a basis for clinical diagnosis in the industrial and medical fields, particularly for cases of debilitating disease which have an effect on physiological performance and effort intolerance. The data at present cannot be applied to men and women over 35 years of age.

  5. Comparison Between Pre-Exhaustion and Traditional Exercise Order on Muscle Activation and Performance in Trained Men

    PubMed Central

    Soares, Enrico Gori; Brown, Lee E.; Gomes, Willy Andrade; Corrêa, Daniel Alves; Serpa, Érica Paes; da Silva, Josinaldo Jarbas; Junior, Guanis de Barros Vilela; Fioravanti, Gustavo zorzi; Aoki, Marcelo Saldanha; Lopes, Charles Ricardo; Marchetti, Paulo Henrique

    2016-01-01

    The purpose of this study was to measure the acute effects of pre-exhaustion vs. traditional exercise order on neuromuscular performance and sEMG in trained men. Fourteen young, healthy, resistance trained men (age: 25.5 ± 4.0 years, height: 174.9 ± 4.1 cm, and total body mass: 80.0 ± 11.1 kg) took part of this study. All tests were randomized and counterbalanced for all subjects and experimental conditions. Volunteers attended one session in the laboratory. First, they performed ten repetition maximum (10RM) tests for each exercise (bench press and triceps pushdown) separately. Secondly, they performed all three conditions at 10RM: pre-test (bench press and triceps pushdown, separately), pre-exhaustion (triceps pushdown+bench press, PE) and traditional (bench press+triceps pushdown, TR), and rested 30 minutes between conditions. Results showed that pre-test was significantly greater than PE (p = 0.031) but not different than TR, for total volume load lifted. There was a significant difference between the pre-test and the time-course of lactate measures (p = 0.07). For bench press muscle activity of the pectoralis major, the last repetition was significantly greater than the first repetition (pre-test: p = 0.006, PE: p = 0.016, and TR: p = 0.005). Also, for muscle activity of the triceps brachii, the last repetition was significantly greater than the first repetition (pre-test: p = 0.001, PE: p = 0.005, and TR: p = 0.006). For triceps pushdown, muscle activity of the triceps brachii, the last repetition was significantly greater than the first repetition (pre-test: p = 0.006, PE: p = 0.016, and TR: p = 0.005). For RPE, there were no significant differences between PE and TR (p = 0.15). Our results suggest that exercise order decreases repetitions performed, however, neuromuscular fatigue, lactate, and RPE are not impacted. The lack of difference in total volume load lifted between PE and TR might explain, at least in part, the similar metabolic and perceptual

  6. Comparison of soleus muscles from rats exposed to microgravity for 10 versus 14 days

    NASA Technical Reports Server (NTRS)

    Staron, R. S.; Kraemer, W. J.; Hikida, R. S.; Reed, D. W.; Murray, J. D.; Campos, G. E.; Gordon, S. E.

    1998-01-01

    The effects of two different duration space-flights on the extent of atrophy, fiber type composition, and myosin heavy chain (MHC) content of rat soleus muscles were compared. Adult male Fisher rats (n=12) were aboard flight STS-57 and exposed to 10 days of microgravity and adult ovariectomized female Spraque-Dawley rats (n=12) were aboard flight STS-62 for 14 days. Soleus muscles were bilaterally removed from the flight and control animals and frozen for subsequent analyses. Muscle wet weights, fiber types (I, IC, IIC, and IIA), cross-sectional area, and MHC content were determined. Although a significant difference was found between the soleus wet weights of the two ground-based control groups, they were similar with regard to MHC content (ca 90% MHCI and ca 10% MHCIIa) and fiber type composition. Unloading of the muscles caused slow-to-fast transformations which included a decrease in the percentage of type I fibers and MHCI, an increase in fibers classified as type IC, and the expression of two fast myosin heavy chains not found in the control rat soleus muscles (MHCIId and MHCIIb). Although the amount of atrophy (ca 26%) and the extent of slow-to-fast transformation (decrease in the percentage of MHCI from 90% to 82.5%) in the soleus muscles were similar between the two spaceflights, the percentages of the fast MHCs differed. After 14 days of spaceflight, the percentage of MHCIIa was significantly lower and the percentages of MHCIId and MHCIIb were significantly higher than the corresponding MHC content of the soleus muscles from the 10-day animals. Indeed, MHCIId became the predominant fast MHC after 14 days in space. These data suggest fast-to-faster transformations continued during the longer spaceflight.

  7. A Comparison of Muscle Activity in Concentric and Counter Movement Maximum Bench Press

    PubMed Central

    van den Tillaar, Roland; Ettema, Gertjan

    2013-01-01

    The purpose of this study was to compare the kinematics and muscle activation patterns of regular free-weight bench press (counter movement) with pure concentric lifts in the ascending phase of a successful one repetition maximum (1-RM) attempt in the bench press. Our aim was to evaluate if diminishing potentiation could be the cause of the sticking region. Since diminishing potentiation cannot occur in pure concentric lifts, the occurrence of a sticking region in this type of muscle actions would support the hypothesis that the sticking region is due to a poor mechanical position. Eleven male participants (age 21.9 ± 1.7 yrs, body mass 80.7 ± 10.9 kg, body height 1.79 ± 0.07 m) conducted 1-RM lifts in counter movement and in pure concentric bench presses in which kinematics and EMG activity were measured. In both conditions, a sticking region occurred. However, the start of the sticking region was different between the two bench presses. In addition, in four of six muscles, the muscle activity was higher in the counter movement bench press compared to the concentric one. Considering the findings of the muscle activity of six muscles during the maximal lifts it was concluded that the diminishing effect of force potentiation, which occurs in the counter movement bench press, in combination with a delayed muscle activation unlikely explains the existence of the sticking region in a 1-RM bench press. Most likely, the sticking region is the result of a poor mechanical force position. PMID:24235985

  8. Comparison of soleus muscles from rats exposed to microgravity for 10 versus 14 days

    NASA Technical Reports Server (NTRS)

    Staron, R. S.; Kraemer, W. J.; Hikida, R. S.; Reed, D. W.; Murray, J. D.; Campos, G. E.; Gordon, S. E.

    1998-01-01

    The effects of two different duration space-flights on the extent of atrophy, fiber type composition, and myosin heavy chain (MHC) content of rat soleus muscles were compared. Adult male Fisher rats (n=12) were aboard flight STS-57 and exposed to 10 days of microgravity and adult ovariectomized female Spraque-Dawley rats (n=12) were aboard flight STS-62 for 14 days. Soleus muscles were bilaterally removed from the flight and control animals and frozen for subsequent analyses. Muscle wet weights, fiber types (I, IC, IIC, and IIA), cross-sectional area, and MHC content were determined. Although a significant difference was found between the soleus wet weights of the two ground-based control groups, they were similar with regard to MHC content (ca 90% MHCI and ca 10% MHCIIa) and fiber type composition. Unloading of the muscles caused slow-to-fast transformations which included a decrease in the percentage of type I fibers and MHCI, an increase in fibers classified as type IC, and the expression of two fast myosin heavy chains not found in the control rat soleus muscles (MHCIId and MHCIIb). Although the amount of atrophy (ca 26%) and the extent of slow-to-fast transformation (decrease in the percentage of MHCI from 90% to 82.5%) in the soleus muscles were similar between the two spaceflights, the percentages of the fast MHCs differed. After 14 days of spaceflight, the percentage of MHCIIa was significantly lower and the percentages of MHCIId and MHCIIb were significantly higher than the corresponding MHC content of the soleus muscles from the 10-day animals. Indeed, MHCIId became the predominant fast MHC after 14 days in space. These data suggest fast-to-faster transformations continued during the longer spaceflight.

  9. A comparison of muscle energy models for simulating human walking in three dimensions.

    PubMed

    Miller, Ross H

    2014-04-11

    The popular Hill model for muscle activation and contractile dynamics has been extended with several different formulations for predicting the metabolic energy expenditure of human muscle actions. These extended models differ considerably in their approach to computing energy expenditure, particularly in their treatment of active lengthening and eccentric work, but their predictive abilities have never been compared. In this study, we compared the predictions of five different Hill-based muscle energy models in 3D forward dynamics simulations of normal human walking. In a data-tracking simulation that minimized muscle fatigue, the energy models predicted metabolic costs that varied over a three-fold range (2.45-7.15 J/m/kg), with the distinction arising from whether or not eccentric work was subtracted from the net heat rate in the calculation of the muscle metabolic rate. In predictive simulations that optimized neuromuscular control to minimize the metabolic cost, all five models predicted similar speeds, step lengths, and stance phase durations. However, some of the models predicted a hip circumduction strategy to minimize metabolic cost, while others did not, and the accuracy of the predicted knee and ankle angles and ground reaction forces also depended on the energy model used. The results highlights the need to clarify how eccentric work should be treated when calculating muscle energy expenditure, the difficulty in predicting realistic metabolic costs in simulated walking even with a detailed 3D musculoskeletal model, the potential for using such models to predict energetically-optimal gait modifications, and the room for improvement in existing muscle energy models and locomotion simulation frameworks. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. A comparison of muscle activity in concentric and counter movement maximum bench press.

    PubMed

    van den Tillaar, Roland; Ettema, Gertjan

    2013-01-01

    The purpose of this study was to compare the kinematics and muscle activation patterns of regular free-weight bench press (counter movement) with pure concentric lifts in the ascending phase of a successful one repetition maximum (1-RM) attempt in the bench press. Our aim was to evaluate if diminishing potentiation could be the cause of the sticking region. Since diminishing potentiation cannot occur in pure concentric lifts, the occurrence of a sticking region in this type of muscle actions would support the hypothesis that the sticking region is due to a poor mechanical position. Eleven male participants (age 21.9 ± 1.7 yrs, body mass 80.7 ± 10.9 kg, body height 1.79 ± 0.07 m) conducted 1-RM lifts in counter movement and in pure concentric bench presses in which kinematics and EMG activity were measured. In both conditions, a sticking region occurred. However, the start of the sticking region was different between the two bench presses. In addition, in four of six muscles, the muscle activity was higher in the counter movement bench press compared to the concentric one. Considering the findings of the muscle activity of six muscles during the maximal lifts it was concluded that the diminishing effect of force potentiation, which occurs in the counter movement bench press, in combination with a delayed muscle activation unlikely explains the existence of the sticking region in a 1-RM bench press. Most likely, the sticking region is the result of a poor mechanical force position.

  11. Generation of intra-oral-like images from cone beam computed tomography volumes for dental forensic image comparison.

    PubMed

    Trochesset, Denise A; Serchuk, Richard B; Colosi, Dan C

    2014-03-01

    Identification of unknown individuals using dental comparison is well established in the forensic setting. The identification technique can be time and resource consuming if many individuals need to be identified at once. Medical CT (MDCT) for dental profiling has had limited success, mostly due to artifact from metal-containing dental restorations and implants. The authors describe a CBCT reformatting technique that creates images, which closely approximate conventional dental images. Using a i-CAT Platinum CBCT unit and standard issue i-CAT Vision software, a protocol is developed to reproducibly and reliably reformat CBCT volumes. The reformatted images are presented with conventional digital images from the same anatomic area for comparison. The authors conclude that images derived from CBCT volumes following this protocol are similar enough to conventional dental radiographs to allow for dental forensic comparison/identification and that CBCT offers a superior option over MDCT for this purpose. © 2013 American Academy of Forensic Sciences.

  12. Changes in volume, muscle compartment, and compliance of the lower extremities in man following 30 days of exposure to simulated microgravity

    NASA Technical Reports Server (NTRS)

    Convertino, Victor A.; Doerr, Donald F.; Buchanan, Paul; Mathes, Karen L.; Stein, Steward L.

    1989-01-01

    To investigate the relationship between leg compliance and a reduction in the size of the leg muscle compartment due to long-duration exposure to microgravity, eight men were exposed for 30 d of continuous 6-deg headdown tilt, and changes in vascular compliance (vol pct/mm Hg x 100) of the calf and serial circumferences of the thigh and the calf were measured before, during, and after the tilt. It was found that the tilt exposure led to calculated leg volume decreases of 9.9 percent in the calf and of 4.5 in the thigh. Leg compliance was found to increase from 3.9 to about 4.9. Calf compliance measured before and after bedrest was found to be inversely related to calf-muscle compartment cross-sectional area (CSA).

  13. Role of heart rate and stroke volume during muscle metaboreflex-induced cardiac output increase: differences between activation during and after exercise.

    PubMed

    Crisafulli, Antonio; Piras, Francesco; Filippi, Michele; Piredda, Carlo; Chiappori, Paolo; Melis, Franco; Milia, Raffaele; Tocco, Filippo; Concu, Alberto

    2011-09-01

    We hypothesized that the role of stroke volume (SV) in the metaboreflex-induced cardiac output (CO) increase was blunted when the metaboreflex was stimulated by exercise muscle ischemia (EMI) compared with post-exercise muscle ischemia (PEMI), because during EMI heart rate (HR) increases and limits diastolic filling. Twelve healthy volunteers were recruited and their hemodynamic responses to the metaboreflex evoked by EMI, PEMI, and by a control dynamic exercise were assessed. The main finding was that the blood pressure increment was very similar in the EMI and PEMI settings. In both conditions the main mechanism used to raise blood pressure was a CO elevation. However, during the EMI test CO was increased as a result of HR elevation whereas during the PEMI test CO was increased as a result of an increase in SV. These results were explainable on the basis of the different HR behavior between the two settings, which in turn led to different diastolic time and myocardial performance.

  14. Comparison of abdominal muscle strength in post-parous and nil parous subjects.

    PubMed

    Sanya, A O; Olajitan, A

    1999-01-01

    This study investigated the relationship between parity and abdominal muscle strength using the Kraus-Weber test. Female volunteers (700) comprising 350 post-parous and 350 nil-parous subjects participated in the study. Physical characteristics of the subjects (age, body weight, height and ponderal index) were measured while the abdominal muscle strength was assessed using three of the six-item Kraus-Weber tests. Results were analysed using descriptive and inferential statistics. Independent t-test showed a significant difference in values of the abdominal. muscle strength of the post-parous and nil-parous subjects (P < 0.05). Pearson's correlation's matrix showed an inverse relationship between parity and scores on the Kraus-Weber test in the post-parous subjects. A significant difference was observed across the parity groups in age, Ponderal index and scores on the Kraus-Weber tests. It was concluded that the abdominal muscle strength of the post-parous subjects was low compared to nil-parous subjects. Due to the ease of application and its non-dependence on the use of sophisticated equipment, it was recommended that the Kraus-Weber test should be used for both subjective assessment and training of abdominal muscle strengths.

  15. Comparison of muscle activation using various hand positions during the push-up exercise.

    PubMed

    Cogley, Robert M; Archambault, Teasha A; Fibeger, Jon F; Koverman, Mandy M; Youdas, James W; Hollman, John H

    2005-08-01

    Popular fitness literature suggests that varied hand placements during push-ups may isolate different muscles. Scientific literature, however, offers scant evidence that varied hand placements elicit different muscle responses. This study examined whether different levels of electromyographic (EMG) activity in the pectoralis major and triceps brachii muscles are required to perform push-ups from each of 3 different hand positions: shoulder width base, wide base, and narrow base hand placements. Forty subjects, 11 men and 29 women, performed 1 repetition of each push-up. The EMG activity for subjects' dominant arm pectoralis major and triceps brachii was recorded using surface electrodes. The EMG activity was greater in both muscle groups during push-ups performed from the narrow base hand position compared with the wide base position (p < 0.05). This study suggests that, if a goal is to induce greater muscle activation during exercise, then push-ups should be performed with hands in a narrow base position compared with a wide base position.

  16. Comparison of loess and purple rill erosions measured with volume replacement method

    NASA Astrophysics Data System (ADS)

    Chen, Xiao-yan; Huang, Yu-han; Zhao, Yu; Mo, Bin; Mi, Hong-xing

    2015-11-01

    Rills are commonly found on sloping farm fields in both the loess and the purple soil regions of China. A comparative study on rill erosion between the two soils is important to increase research knowledge and exchange application experiences. Rill erosion processes of loess and purple soils were determined through laboratory experiments with the volume replacement method. Water was used to refill the eroded rill segments to compute eroded volume before sediment concentration distribution along the rill was computed using the soil bulk density, flow rate, and water flow duration. The experimental loess soil materials were from the Loess Plateau and purple soil from the southwestern part of China, Chongqing City. A laboratory experimental platform was used to construct flumes to simulate rills with 12.0 m length, 0.1 m width, and 0.3 m depth. Soil materials were filled into the flumes at a bulk density of 1.2 g cm-3 to a depth of 20 cm to form rills for experiments on five slope gradients (5°, 10°, 15°, 20°, and 25°) and three flow rates (2, 4, and 8 L/min). After each experimental run under the given slope gradient and flow rate, the rill segments from the upper slope between 0-0.5, 0.5-1, 1-2, 2-3, …, 7-8, 8-10, and 10-12 m were lined with plastic sheets before be re-filled with water to determine sediment concentration after the eroded volumes was measured. Rill erosion differed between the two soils. As purple soil started to erode at a higher erosive force than loess soil, it possibly exhibits higher resistance to water erosion. The subsequent erosion process in the eroding purple rill was similar to that in the loess rill. However, the total erosion in the eroding loess rill was more than that in the eroding purple rill. The maximum sediment concentration transported by the eroding purple rills was significantly lower, approximately 55% of those transported by the loess rills under the same flow rate and slope gradient. Hence, less purple sediments can

  17. Routine gastric residual volume measurement and energy target achievement in the PICU: a comparison study.

    PubMed

    Tume, Lyvonne N; Bickerdike, Anna; Latten, Lynne; Davies, Simon; Lefèvre, Madeleine H; Nicolas, Gaëlle W; Valla, Frédéric V

    2017-09-18

    Critically ill children frequently fail to achieve adequate energy intake, and some care practices, such as the measurement of gastric residual volume (GRV), may contribute to this problem. We compared outcomes in two similar European Paediatric Intensive Care Units (PICUs): one which routinely measures GRV (PICU-GRV) to one unit that does not (PICU-noGRV). An observational pilot comparison study was undertaken. Eighty-seven children were included in the study, 42 (PICU-GRV) and 45 (PICU-noGRV). There were no significant differences in the percentage of energy targets achieved in the first 4 days of PICU admission although PICU-noGRV showed more consistent delivery of median (and IQR) energy targets and less under and over feeding for PICU-GRV and PICU-noGRV: day 1 37 (14-72) vs 44 (0-100), day 2 97 (53-126) vs 100 (100-100), day 3 84 (45-112) vs 100 (100-100) and day 4 101 (63-124) vs 100 (100-100). The incidence of vomiting was higher in PICU-GRV. No necrotising enterocolitis was confirmed in either unit, and ventilator-acquired pneumonia rates were not significantly different (7.01 vs 12 5.31 per 1000 ventilator days; p = 0.70) between PICU-GRV and PICU-noGRV units. The practice of routine gastric residual measurement did not significantly impair energy targets in the first 4 days of PICU admission. However, not measuring GRV did not increase vomiting, ventilator-acquired pneumonia or necrotising enterocolitis, which is the main reason clinicians cite for measuring GRV. What is known: • The practice of routinely measuring gastric residual volume is widespread in critical care units • This practice is increasingly being questioned in critically ill patients, both as a practice that increases • The likelihood of delivering inadequate enteral nutrition amounts and as a tool to assess feeding tolerance What is new: • Not routinely measuring gastric residual volume did not increase adverse events of ventilator acquired pneumonia, necrotising enterocolitis

  18. KEY COMPARISON: Final report on regional key comparison SIM.M.FF-K4: Volume of liquids at 20 L and 100 mL

    NASA Astrophysics Data System (ADS)

    Arias, Roberto; Maldonado, Manuel; Wright, John; Wallace, Tanisha; Rodríguez, Sandra; Pinzón, Orlando; Morales, Abed; Vega, Maria; Santo, Claudia; Kornblit, Fernando; Malta, Dalni

    2010-01-01

    At its meeting in October 2006 in Querétaro, Mexico, the Interamerican Metrology System (SIM) Technical Committee for Fluid Flow (TCFF) approved a Regional Key Comparison for Volume of Liquids at 20 L and 100 mL, to be piloted by the national metrology institute of Mexico (CENAM). The objective of this comparison was to demonstrate the degree of equivalence of the volume measurement standards held at national measurement institutes (NMIs) and to provide supporting evidence for the Calibration and Measurement Capabilities (CMCs) claimed by the participating laboratories in the Americas. During the comparison, one of the pycnometers suffered irreversible damage, and degrees of equivalence for volume at 100 mL were calculated using the results obtained with one single pycnometer (TS 03.04.04). Conclusions are as follows: The transfer standards for SIM.M.FF-K4 exhibited global good performance all the way along, both in terms of stability and repeatability. Degrees of equivalence have been produced for volumes at 20 L and at 100 mL. The best estimation of the measurands, as reported by the participants, shows a general agreement better than +/-0.0070% for volume of liquids at 100 mL and 20 L. It is advisable to review the uncertainty analysis of some participants. New CMC entries for some NMIs should take into account the information presented in this Report. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  19. KEY COMPARISON: Results of the key comparison CCM.FF-K4 for volume of liquids at 20 L and 100 mL

    NASA Astrophysics Data System (ADS)

    Arias, Roberto; Maldonado, Manuel; Wright, John; Jacques, Claude; Lachance, Christian; Lau, Peter; Többen, Helmut; Cignolo, Giorgio; Lorefice, Salvatore; Man, John; Aibe, Valter Y.

    2006-01-01

    A key comparison was performed in order to compare national measurement systems to determine volume of liquids, particularly at fixed volumes of 20 L and 100 mL. The participants were CENAM (Mexico), NIST (United States of America), NRC/MC (Canada), SP (Sweden), PTB (Germany), INRIM (former IMGC, Italy), NMIA (Australia) and INMETRO (Brazil). CENAM acted as pilot laboratory. The measurements were carried out from December 2003 to March 2005. The chosen values of volume (20 L and 100 mL) are both representatives of the Calibration and Measurement Capabilities (CMCs) declared by most of the participating national metrology institutes. The transfer standards (TSs) were three stainless steel pipettes for volume at 20 L and six commercially available glass pycnometers for volume at 100 mL. Prior to the beginning of the key comparison, the 20 L TSs were tested by CENAM, SP and NMIA The results of the test phase showed excellent values for both repeatability and reproducibility. During the CCM.FF-K4, the results of most of the laboratories showed good agreement with the reference values. The best estimation of the measurands, as reported by the participants showed a general agreement better than ±0.0025% for volume of liquids at 100 mL and 20 L. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  20. Performance and muscle architecture comparisons between starters and nonstarters in National Collegiate Athletic Association Division I women's soccer.

    PubMed

    Jajtner, Adam R; Hoffman, Jay R; Scanlon, Tyler C; Wells, Adam J; Townsend, Jeremy R; Beyer, Kyle S; Mangine, Gerald T; McCormack, William P; Bohner, Jonathan D; Fragala, Maren S; Stout, Jeffery R

    2013-09-01

    This study compared performance and muscle architecture (MA) changes in starters (S) and nonstarters (NS) during a National Collegiate Athletic Association Division I women's soccer season. Twenty-eight women (19.9 ± 1.1 years; 1.71 ± 0.08 m; 64.7 ± 6.4 kg) were monitored for vertical jump power (VJP), repeated line drills (LDs), 3-dimensional multiple object tracking (3D-MOT), and reaction time (RT) at preseason, midseason, and postseason. Muscle architecture changes using ultrasonography were assessed at preseason and postseason. Comparisons between S (n = 11; 70.0 ± 14.6 min per game) and NS (n = 17; 8.4 ± 8.0 min per game) were performed to make magnitude-based inferences. No differences were seen in VJP during the season in either group. Starters were more likely (81.1%) to decrease LD time than NS, with no differences in fatigue rate. Starters and NS improved 3D-MOT (1.14 ± 0.41 to 1.55 ± 0.43) and RT (0.37 ± 0.05 to 0.34 ± 0.33 seconds), with no differences between groups. Rectus femoris (RF) echo intensity improved (65.57 ± 1.50 to 61.26 ± 1.59) in both groups, with no interactions observed. Cross-sectional area (20.84 ± 3.58 to 21.46 ± 3.66 cm) increased and pennation angle (PANG) (12.58 ± 2.56 to 11.78 ± 2.03°) decreased for both groups in the vastus lateralis (VL). Muscle architecture comparisons between groups revealed S likely decreased VL muscle thickness (MT) and PANG (81.6 and 79.4%, respectively) and possibly decreased RF MT and PANG (65.7 and 59.4%, respectively) when compared with NS. Results indicate that VJP and LD fatigue rate are not changed during a competitive season, but S become faster than NS. Three-dimensional multiple object tracking and RT improve regardless of playing time. Changes in MA indicate that practices alone provide sufficient stimulus for improving muscle quality during the competitive season.

  1. Comparison of hemp and cotton fiber implants in muscle rat tissue. Study of the inflammatory response.

    PubMed

    Dorfman, S; Dorfman, D; Leonardi, R; Maroso, J; Cardozo, J; Durán, A

    1994-03-01

    Hemp fiber is obtained from the plant Musa textilis. The cost of preparation of its raw fibers is low. The purpose of this paper was to compare the inflammatory response in the rat muscle tissue originated by both hemp and cotton fibers. Both types of fibers, were implanted in gluteal muscles of Sprague Dawley rats. The rats were sacrificed at 15, 30 and 60 postoperative days. Muscle tissue sections were stained with hematoxilyneosin. The inflammatory response was measured by subtracting the suture surface area from the total granulomatous area. At 15 days, the inflammatory response was more conspicuous for hemp than for cotton fiber (P < 0.05). At 30 and 60 days, responses were similar (P > 0.05). We cannot conclude that the hemp fiber is superior to cotton, nevertheless, they behave the same. Therefore, hemp constitutes an alternative as suture material.

  2. Comparison of sensory modes of biofeedback in relaxation training of frontalis muscle.

    PubMed

    Chen, W

    1981-12-01

    The purpose of this study was to compare the effectiveness of various sensory modes of EMG biofeedback to relaxation training of the frontalis muscle. 19 male and 29 female subjects were randomly selected from a pool of college volunteers. They were then randomly assigned 12 each to audiofeedback, visual feedback, audiovisual feedback, and no feedback groups. There were 11 20-min. sessions per subject. Subjects in the biofeedback groups were trained to reduce muscle tension voluntarily by utilizing Cyborg J33 EMG portable trainers. The subjects in the three feedback groups exhibited significantly lower muscle tension than did the subjects in the no-feedback control group. There were no significant differences in relaxation among the three feedback groups.

  3. Comparison of Lower Limb Muscle Activity during Eccentric and Concentric Exercises in Runners with Achilles Tendinopathy

    PubMed Central

    Yu, Jaeho

    2014-01-01

    [Purpose] This study aimed to identify changes in muscle activation by comparing muscle activities of the affected side (AS) and non-affected side (NAS) during eccentric and concentric exercises in runners with unilateral Achilles tendinopathy. [Subjects] The study included 18 participants consisting of men and women with chronic Achilles tendinopathy in a single leg who had more than 1 year of running experience. [Methods] All subjects performed concentric and eccentric exercise with the Achilles tendon moving from full plantar flexion to full dorsiflexion for 8 seconds, and electromyography data was obtained. [Results] All muscles examined showed a significant increase in %maximal voluntary contraction (MVC) with concentric exercise compared with eccentric exercise. Compared with the NAS, the AS showed significant increases in %MVC of the rectus femoris, tibialis anterior, and lateral gastrocnemius. All interaction effects of exercise methods and injuries showed statistically significant changes. [Conclusion] Runners with Achilles tendinopathy show increases in medial gastrocnemius activity when performing eccentric exercise. PMID:25276014

  4. Comparison of pelvic floor muscle strength evaluations in nulliparous and primiparous women: a prospective study

    PubMed Central

    Gameiro, Mônica Orsi; Sousa, Vanessa Oliveira; Gameiro, Luiz Felipe; Muchailh, Rosana Carneiro; Padovani, Carlos Roberto; Amaro, João Luiz

    2011-01-01

    OBJECTIVE: This study aimed to compare the pelvic floor muscle strength of nulliparous and primiparous women. METHODS: A total of 100 women were prospectively distributed into two groups: Group 1 (G1) (n = 50) included healthy nulliparous women, and Group 2 (G2) (n = 50) included healthy primiparous women. Pelvic floor muscle strength was subjectively evaluated using transvaginal digital palpation. Pelvic floor muscle strength was objectively assessed using a portable perineometer. All of the parameters were evaluated simultaneously in G1 and were evaluated in G2 during the 20th and 36th weeks of pregnancy and 45 days after delivery. RESULTS: In G2, 14 women were excluded because they left the study before the follow-up evaluation. The median age was 23 years in G1 and 22 years in G2; there was no significant difference between the groups. The average body mass index was 21.7 kg/m2 in G1 and 25.0 kg/m2 in G2; there was a significant difference between the groups (p = 0.0004). In G2, transvaginal digital palpation evaluation showed significant impairments of pelvic floor muscle strength at the 36th week of pregnancy (p = 0.0006) and 45 days after vaginal delivery (p = 0.0001) compared to G1. Objective evaluations of pelvic floor muscle strength in G2 revealed a significant decrease 45 days after vaginal delivery compared to nulliparous patients. CONCLUSION: Pregnancy and vaginal delivery may cause weakness of the pelvic floor muscles. PMID:21915489

  5. A comparison of hamstring muscle activity during different screening tests for non-contact ACL injury.

    PubMed

    Husted, Rasmus S; Bencke, Jesper; Andersen, Lars L; Myklebust, Grethe; Kallemose, Thomas; Lauridsen, Hanne B; Hölmich, Per; Aagaard, Per; Zebis, Mette K

    2016-06-01

    Reduced ability to activate the medial hamstring muscles during a sports-specific sidecutting movement has been found to be a potential risk factor for non-contact ACL injury. However, whether a reduced ability to activate the medial hamstring muscle is a general neuromuscular phenomenon and thereby observable independently of the type of clinical screening tests used is not known. This cross sectional study investigated the rank correlation of knee joint neuromuscular activity between three different ACL injury risk screening tests. Sixty-two adolescent female elite football and handball players (16.7±1.3years) participated in the study. Using surface electromyography (EMG) assessment, the neuromuscular activity of medial hamstring muscle (semitendinosus, ST), lateral hamstring muscle (biceps femoris, BF) and quadriceps muscle (vastus lateralis, VL) were monitored during three standardized screening tests - i.e. one-legged horizontal hop (OLH), drop vertical jump (DJ) and sidecutting (SC). Neuromuscular pre-activity was measured in the time interval 10ms prior to initial contact on a force plate. For neuromuscular hamstring muscle pre-activity, correlation analysis (Spearman correlation coefficient) showed low-to-moderate correlations between SC and 1) DJ (rs=0.34-0.36, P<0.05) and 2) OLH (rs=0.40-0.41, P<0.05), respectively. In conclusion, the present data suggest that hamstring pre-activity share some common variance during the examined tests. However, a lack of strong correlation suggests that we cannot generalize one risk factor during one test to another test. The present data demonstrate that one-legged horizontal hop and drop vertical jump testing that are commonly used in the clinical setting does not resemble the specific neuromuscular activity patterns known to exist during sidecutting, a well known high risk movement for non-contact ACL injury. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Comparison of swim recovery and muscle stimulation on lactate removal after sprint swimming.

    PubMed

    Neric, Francis B; Beam, William C; Brown, Lee E; Wiersma, Lenny D

    2009-12-01

    Competitive swimming requires multiple bouts of high-intensity exercise, leading to elevated blood lactate. Active exercise recovery has been shown to lower lactate faster than passive resting recovery but may not always be practical. An alternative treatment, electrical muscle stimulation, may have benefits similar to active recovery in lowering blood lactate but to date is unstudied. Therefore, this study compared submaximal swimming and electrical muscle stimulation in reducing blood lactate after sprint swimming. Thirty competitive swimmers (19 men and 11 women) participated in the study. Each subject completed 3 testing sessions consisting of a warm-up swim, a 200-yard maximal frontcrawl sprint, and 1 of 3 20-minute recovery treatments administered in random order. The recovery treatments consisted of a passive resting recovery, a submaximal swimming recovery, or electrical muscle stimulation. Blood lactate was tested at baseline, after the 200-yard sprint, and after 10 and 20 minutes of recovery. A significant interaction (p < 0.05) between recovery treatment and recovery time was observed. Blood lactate levels for the swimming recovery were significantly lower at 10 minutes (3.50 +/- 1.57 mmol.L-1) and 20 minutes (1.60 +/- 0.57 mmol.L-1) of recovery than either of the other 2 treatments. Electrical muscle stimulation led to a lower mean blood lactate (3.12 +/- 1.41 mmol.L-1) after 20 minutes of recovery compared with passive rest (4.11 +/- 1.35 mmol.L-1). Submaximal swimming proved to be most effective at lowering blood lactate, but electrical muscle stimulation also reduced blood lactate 20 minutes postexercise significantly better than resting passive recovery. Electrical muscle stimulation shows promise as an alternate recovery treatment for the purpose of lowering blood lactate.

  7. Comparison of location, depth, quality, and intensity of experimentally induced pain in 6 low back muscles.

    PubMed

    Tucker, Kylie J; Fels, Matthew; Walker, Scott R; Hodges, Paul W

    2014-09-01

    The pattern of pain originating from experimentally induced low back pain appears diffuse. This may be because sensory information from low back muscles converges, sensory innervation extends over multiple vertebral levels, or people have difficulty accurately representing the painful location on standardized pain maps. The aim of this study was to provide insight into the perception of pain from noxious stimulation of a range of low back muscles using novel depth and location measures. Hypertonic saline (1 mL, 7% NaCl) was injected into bellies of longissimus (LO), quadratus lumborum (QL), superficial multifidus (SM), and deep multifidus (DM) at the level of the fourth lumbar vertebrae (L4) and in SM and DM at L5 using ultrasound guidance over 6 sessions. Fifteen participants reported depth, location, intensity, size, and descriptive quality of pain throughout the painful period (∼14 min). Pain was reported deeper (P<0.04) for DML4/L5 compared with SML4/L5, LO and QL; more cranial for LO compared with DML4 and QL (P<0.01); more lateral for LO compared with DML4 (P<0.02); and more lateral for QL compared with all other muscles at L4 (P<0.0001). Pain intensity was higher in DML4/L5 than all other muscles (P<0.04) for ∼3 minutes. Descriptive qualities varied slightly between muscles. Depth and lateral position may be the most critical descriptors to determine the source of acute lumbar muscular pain. Overlapping regions of pain may be explained by convergence of receptive fields, innervation of multifidus fascicles at multiple lumbar segments, and convergence of sensory input from different muscles to the same sensory cell bodies as demonstrated in the lumbar spine of animal preparations.

  8. Relationships of peak leg power, 1 maximal repetition half back squat, and leg muscle volume to 5-m sprint performance of junior soccer players.

    PubMed

    Chelly, Mohamed Souhaiel; Chérif, Najet; Amar, Mohamed Ben; Hermassi, Souhail; Fathloun, Mourad; Bouhlel, Ezdine; Tabka, Zouhair; Shephard, Roy J

    2010-01-01

    Performance over very short distances (1-5 m) is important in soccer. We investigated this in 23 male regional-level soccer players aged 17.2 +/- 0.7 years, filming body markers to determine the average velocity and acceleration over the first step (V(S) and A(S)) and the first 5 m (V(5), A(5)). Data were related to scores on a force-velocity test, squat jump (SJ), countermovement jump (CMJ), and 1 maximal repetition (1 RM) half back squat. Leg and thigh muscle volumes were also assessed anthropometrically. V(5) was positively correlated with leg and thigh muscle volumes (r = 0.61, p < 0.05; r = 0.43, p < 0.05, respectively), SJ power (absolute and relative to body mass, r = 0.45, p < 0.05; r = 0.43, p < 0.05, respectively), absolute force-velocity leg power (r = 0.49, p < 0.05), and 1 RM half back squat (r = 0.66, p < 0.001). The use of dimensional exponents did not change coefficients materially. V(S) was also correlated with leg muscle volume and 1 RM back half squat (r = 0.56, p < 0.01; r = 0.58, p < 0.01, respectively) and more weakly with force-velocity leg power and SJ force (r = 0.49, p < 0.05; r = 0.46, p < 0.5, respectively). However, the CMJ was unrelated to velocity or acceleration. Sprinting ability is correlated with measures of power and force such as the force-velocity test, SJ, and 1 RM half back squat; such measures thus offer useful guidance to soccer coaches who wish to improve the short-distance velocity of their players.

  9. A practical model of low-volume high-intensity interval training induces mitochondrial biogenesis in human skeletal muscle: potential mechanisms.

    PubMed

    Little, Jonathan P; Safdar, Adeel; Wilkin, Geoffrey P; Tarnopolsky, Mark A; Gibala, Martin J

    2010-03-15

    High-intensity interval training (HIT) induces skeletal muscle metabolic and performance adaptations that resemble traditional endurance training despite a low total exercise volume. Most HIT studies have employed 'all out', variable-load exercise interventions (e.g. repeated Wingate tests) that may not be safe, practical and/or well tolerated by certain individuals. Our purpose was to determine the performance, metabolic and molecular adaptations to a more practical model of low-volume HIT. Seven men (21 + or - 0.4 years, V(O2peak) = 46 + or - 2 ml kg(-1) min(-1)) performed six training sessions over 2 weeks. Each session consisted of 8-12 x 60 s intervals at approximately 100% of peak power output elicited during a ramp V(O2) peak test (355 + or - 10 W) separated by 75 s of recovery. Training increased exercise capacity, as assessed by significant improvements on both 50 kJ and 750 kJ cycling time trials (P < 0.05 for both). Skeletal muscle (vastus lateralis) biopsy samples obtained before and after training revealed increased maximal activity of citrate synthase (CS) and cytochrome c oxidase (COX) as well as total protein content of CS, COX subunits II and IV, and the mitochondrial transcription factor A (Tfam) (P < 0.05 for all). Nuclear abundance of peroxisome proliferator-activated receptor gamma co-activator 1alpha (PGC-1alpha) was approximately 25% higher after training (P < 0.05), but total PGC-1alpha protein content remained unchanged. Total SIRT1 content, a proposed activator of PGC-1alpha and mitochondrial biogenesis, was increased by approximately 56% following training (P < 0.05). Training also increased resting muscle glycogen and total GLUT4 protein content (both P < 0.05). This study demonstrates that a practical model of low volume HIT is a potent stimulus for increasing skeletal muscle mitochondrial capacity and improving exercise performance. The results also suggest that increases in SIRT1, nuclear PGC-1alpha, and Tfam may be involved in

  10. Perceived loading and muscle activity during hip strengthening exercises: comparison of elastic resistance and machine exercises.

    PubMed

    Brandt, Mikkel; Jakobsen, Markus Due; Thorborg, Kristian; Sundstrup, Emil; Jay, Kenneth; Andersen, Lars L

    2013-12-01

    Decreased hip muscle strength is frequently reported in patients with hip injury or pathology. Furthermore, soccer players suffering from groin injury show decreased strength of hip muscles. Estimating 10-repetition maximum can be time-consuming and difficult, thus, using the Borg category rating 10 scale (Borg CR10 scale) can be a useful tool for estimating the intensity of exercise. The aims of this study were 1) to investigate the feasibility of the use of the Borg CR10 scale for rating strength training intensity of the hip abductor and hip adductor muscles, and 2) to compare hip muscle activity during hip abduction and hip adduction exercises using elastic resistance and isotonic machines, using electromyography (EMG). EMG activity was recorded from 11 muscles at the hip, thigh and trunk during hip adduction and hip abduction exercises in 16 untrained women, using elastic resistance and isotonic exercise machines. These recordings were normalized to maximal voluntary contraction (MVC) EMG (nEMG). The exercises were performed at four levels of perceived loading reported using the Borg CR10: light (Borg ≤2), moderate (Borg >2-<5), heavy (Borg ≥5-<7) and near maximum (Borg ≥7). Moderate to strong associations were observed between perceived loading and nEMG obtained during the adduction exercise with elastic resistance (r=0.8±0.3) as well as in machine (r=0.69±0.55) and the abduction exercise with elastic resistance (r=0.66±0.29) as well as in machine (r =0.62±0.54). The abduction exercise performed with elastic resistance displayed significantly higher gluteus medius nEMG recruitment than the in machine exercise. The results of this study show that the Borg CR10 scale can be a useful tool for estimating intensity levels during resistance training of the hip adductor and hip abductor muscles. Although elastic resistance and exercise machine seem equally effective for recruiting muscle activity of the hip adductors, the elastic resistance condition was

  11. Muscle strength and function of shoulders with Bankart lesion after successful arthroscopic treatment: interlimb comparison 24 months after surgery.

    PubMed

    Tahta, Mesut; Akmeşe, Ramazan; Özberk, Zekiye Nisa; Coşkun, Ozlem Oner; Işik, Çetin; Korkusuz, Feza; Bozkurt, Murat

    2013-12-01

    The purpose of this study was to examine outcomes following arthroscopic Bankart repair with the focus on strength after the repair. 56 shoulders with Bankart lesion were operated on arthroscopically. Gender, mechanism of the first dislocation, number of dislocations, dominant side, operated side and the number of anchors used for surgery were recorded. DASH and Oxford instability scoring systems were applied preoperatively and compared to scores at the 24-month follow-up. The scoring systems were also applied to contralateral shoulders at the 24th month of follow-up. Range of motion was measured with a goniometer. Muscle strength was analyzed with a dynamometer simultaneously with the muscle activity of four perishoulder muscles. The data were recorded with surface EMG. Range of motion, muscle strength and activity were evaluated according to the contralateral shoulder at the 24th month of follow-up. Male/female ratio was 42/14 with a mean age of 32 years. The mean number of dislocations was 3 ± 1 and all were traumatic dislocations. The number of mean anchors used was 3.1 and the mean follow-up period was 24 months. In clinical evaluation, the preoperative and postoperative results of the DASH and Oxford instability scores of the unstable shoulders were significantly different. In the comparison between the operated and contralateral shoulders, there was no significant difference in DASH and Oxford instability scores at the 24th month of follow-up. There was no significant loss of range of motion. Only internal rotation strength was significantly reduced and there was no significant change in the EMG patterns. Although good clinical results can be achieved, internal rotation strength is reduced after arthroscopic surgery, but daily activities are not affected. There is no guarantee for patients of excellent recovery. Level III cohort study.

  12. Age-associated differences in triceps surae muscle composition and strength – an MRI-based cross-sectional comparison of contractile, adipose and connective tissue

    PubMed Central

    2014-01-01

    Background In human skeletal muscles, the aging process causes a decrease of contractile and a concomitant increase of intramuscular adipose (IMAT) and connective (IMCT) tissues. The accumulation of non-contractile tissues may contribute to the significant loss of intrinsic muscle strength typically observed at older age but their in vivo quantification is challenging. The purpose of this study was to establish MR imaging-based methods to quantify the relative amounts of IMCT, IMAT and contractile tissues in young and older human cohorts, and investigate their roles in determining age-associated changes in skeletal muscle strength. Methods Five young (31.6 ± 7.0 yrs) and five older (83.4 ± 3.2 yrs) Japanese women were subject to a detailed MR imaging protocol, including Fast Gradient Echo, Quantitative Fat/Water (IDEAL) and Ultra-short Echo Time (UTE) sequences, to determine contractile muscle tissue and IMAT within the entire Triceps Surae complex, and IMCT within both heads of the Gastrocnemius muscle. Specific force was calculated as the ratio of isometric plantarflexor force and the physiological cross-sectional area of the Triceps Surae complex. Results In the older cohort, total Triceps Surae volume was smaller by 17.5%, while the relative amounts of Triceps Surae IMAT and Gastrocnemius IMCT were larger by 55.1% and 48.9%, respectively. Differences of 38.6% and 42.1% in plantarflexor force and specific force were observed. After subtraction of IMAT and IMCT from total muscle volume, differences in intrinsic strength decreased to 29.6%. Conclusions Our data establishes that aging causes significant changes in skeletal muscle composition, with marked increases in non-contractile tissues. Such quantification of the remodeling process is likely to be of functional and clinical importance in elucidating the causes of the disproportionate age-associated decrease of force compared to that of muscle volume. PMID:24939372

  13. Comparison of the effects of electrical stimulation and cold-water immersion on muscle soreness after resistance exercise.

    PubMed

    Jajtner, Adam R; Hoffman, Jay R; Gonzalez, Adam M; Worts, Phillip R; Fragala, Maren S; Stout, Jeffrey R

    2015-05-01

    Resistance training is a common form of exercise for competitive and recreational athletes. Enhancing recovery from resistance training may improve the muscle-remodeling processes, stimulating a faster return to peak performance. To examine the effects of 2 different recovery modalities, neuromuscular electrical stimulation (NMES) and cold-water immersion (CWI), on performance and biochemical and ultrasonographic measures. Thirty resistance-trained men (23.1 ± 2.9 y, 175.2 ± 7.1 cm, 82.1 ± 8.4 kg) were randomly assigned to NMES, CWI, or control (CON). All participants completed a high-volume lower-body resistance-training workout on d 1 and returned to the human performance laboratory 24 (24H) and 48 h (48 H) postexercise for follow-up testing. Blood samples were obtained preexercise (PRE) and immediately (IP), 30 min (30 P), 24 h (24H), and 48 h (48 H) post. Subjects were examined for performance changes in the squat exercise (total repetitions and average power per repetition), biomarkers of inflammation, and changes in cross-sectional area and echo intensity (EI) of the rectus femoris (RF) and vastus lateralis muscles. No differences between groups were observed in the number of repetitions (P = .250; power: P = .663). Inferential-based analysis indicated that increases in C-reactive protein concentrations were likely increased by a greater magnitude after CWI compared with CON, while NMES possibly decreased more than CON from IP to 24H. Increases in interleukin-10 concentrations between IP and 30 P were likely greater in CWI than NMES but not different from CON. Inferential-based analysis of RF EI indicated a likely decrease for CWI between IP and 48 H. No other differences between groups were noted in any other muscle-architecture measures. Results indicated that CWI induced greater increases in pro- and anti-inflammatory markers, while decreasing RF EI, suggesting that CWI may be effective in enhancing short-term muscle recovery after high-volume bouts of

  14. A comparison of rat myosin from fast and slow skeletal muscle and the effect of disuse

    NASA Technical Reports Server (NTRS)

    Unsworth, B. R.; Witzmann, F. A.; Fitts, R. H.

    1981-01-01

    Certain enzymatic and structural features of myosin, purified from rat skeletal muscles representative of the fast twitch glycolytic (type IIb), the fast twitch oxidative (type IIa), and the slow twitch oxidative (type I) fiber, were determined and the results were compared with the measured contractile properties. Good correlation was found between the shortening velocities and Ca(2+)-activated ATPase activity for each fiber type. Short term hind limb immobilization caused prolongation of contraction time and one-half relaxation time in the fast twitch muscles and a reduction of these contractile properties in slow twitch soleus. Furthermore, the increased maximum shortening velocity in the immobilized soleus could be correlated with increased Ca(2+)-ATPase, but no change was observed in the enzymatic activity of the fast twitch muscles. No alteration in light chain distribution with disuse was observed in any of the fiber types. The myosin from slow twitch soleus could be distinguished from fast twitch myosins on the basis of the pattern of peptides generated by proteolysis of the heavy chains. Six weeks of hind limb immobilization resulted in both an increased ATPase activity and an altered heavy chain primary structure in the slow twitch soleus muscle.

  15. [Muscle relaxants in Germany 2005: a comparison of application customs in hospitals and private practices].

    PubMed

    Fink, H; Geldner, G; Fuchs-Buder, T; Hofmockel, R; Ulm, K; Wallek, B; Blobner, M

    2006-06-01

    Aim of this study was to evaluate application customs of muscles relaxants in hospitals compared to their use in private practice. Of the 3,260 questionnaires sent-out, 66.9% could be analyzed. Of these 54% were from anesthetists in private practice, 41% from heads of hospital anesthesia departments and 5% from heads of level one hospital anesthesia departments. The first difference between private practices and hospitals was the number of available muscle relaxants: 87% of private practices use 1-3 relaxants, whereas 79% of hospitals use 3-5. Another apparent difference was the relationship between general anesthesia and the number of intubations: 60% of private practices have over 80% of general anesthesia cases, but only 50% of these patients are intubated. On the contrary, two thirds of the hospitals have 50-80% general anesthesia cases and 60-70% of patients are intubated. The main wish for an ideal muscle relaxant was independent of private practice or hospital, short onset time, followed by fast recovery. In accordance 74% of anesthetists in hospitals and 72% of anesthetists in private practice voiced the wish for a non-depolarizing succinylcholine substitute. The results of this nationwide survey suggest that time pressure in combination with an increased specialization of anesthetists in private practice are the main factors for availability and use of muscle relaxants in routine anesthesia.

  16. Leg Muscle Involvement in Facioscapulohumeral Muscular Dystrophy: Comparison between Facioscapulohumeral Muscular Dystrophy Types 1 and 2.

    PubMed

    Mair, Dorothea; Huegens-Penzel, Monika; Kress, Wolfram; Roth, Christian; Ferbert, Andreas

    2017-01-01

    Facioscapulohumeral muscular dystrophy (FSHD) presents with 2 genetically distinct types. We describe for the first time the MRI patterns of leg muscle involvement in type 2 and compare it with type 1. The intramuscular fat content was assessed on lower extremity axial T1-weighted MRI scans in 6 FSHD1 and 5 FSHD2 patients. Overall, the muscle involvement profile did not differ substantially between FSHD1 and FSHD2. In the thigh, the dorsomedial compartment including the semimembranosus, semitendinosus and adductor magnus was the most affected. The quadriceps was mostly spared, but isolated involvement of the rectus femoris was common. Fat infiltration in the distal soleus and the medial gastrocnemius with sparing of the lateral gastrocnemius was a common finding; involvement of the tibialis anterior was less frequent. A proximal-to-distal increase in fat content was frequently present in some muscles. Muscle involvement appears to be independent of type, confirming a similar pathophysiological pathway in FSHD1 and FSHD2. © 2016 S. Karger AG, Basel.

  17. A Comparison of Exercise-Induced Muscle Damage Following Maximal Eccentric Contractions in Men and Boys.

    PubMed

    Deli, Chariklia K; Fatouros, Ioannis G; Paschalis, Vassilis; Georgakouli, Kalliopi; Zalavras, Athanasios; Avloniti, Alexandra; Koutedakis, Yiannis; Jamurtas, Athanasios Z

    2017-08-01

    Research regarding exercise-induced muscle-damage mainly focuses on adults. The present study examined exercise-induced muscle-damage responses in adults compared with children. Eleven healthy boys (10-12 y) and 15 healthy men (18-45 y) performed 5 sets of 15 maximal eccentric contractions of the knee extensors. Range of motion (ROM), delayed onset muscle soreness (DOMS) during squat and walking, and peak isometric, concentric and eccentric torque were assessed before, post, 24, 48, 72, and 96 hr postexercise. Creatine kinase (CK) activity was assessed before and 72 hr postexercise. Eccentric exercise resulted in DOMS during squat that persisted for up to 96h in men, and 48 hr in boys (p < .05), and DOMS during walking that persisted for up to 72 hr in men, and 48 hr in boys (p < .01). The ROM was lower in both age groups 48 hr postexercise (p < .001). Isometric (p < .001), concentric (p < .01) and eccentric (p < .01) force decreased post, and up to 48 hr postexercise in men. Except for a reduction in isometric force immediately after exercise, no other changes occurred in boys' isokinetic force. CK activity increased in men at 72 hr postexercise compared with pre exercise levels (p = .05). Our data provide further confirmation that children are less susceptible to exercise-induced muscle damage compared with adults.

  18. Comparison of muscle activity patterns of transfemoral amputees and control subjects during walking

    PubMed Central

    2013-01-01

    Background Only few studies have looked at electromyography (EMG) during prosthetic gait. Differences in EMG between normal and prosthetic gait for stance and swing phase were never separately analyzed. These differences can give valuable information if and how muscle activity changes in prosthetic gait. Methods In this study EMG activity during gait of the upper leg muscles of six transfemoral amputees, measured inside their own socket, was compared to that of five controls. On and off timings for stance and swing phase were determined together with the level of co-activity and inter-subject variability. Results and conclusions Gait phase changes in amputees mainly consisted of an increased double support phase preceding the prosthetic stance phase. For the subsequent (pre) swing phase the main differences were found in muscle activity patterns of the prosthetic limb, more muscles were active during this phase and/or with prolonged duration. The overall inter-subject variability was larger in amputees compared to controls. PMID:23914785

  19. Comparison of palatability characteristics of beef gluteus medius and triceps brachii muscles

    USDA-ARS?s Scientific Manuscript database

    The objective of this experiment was to evaluate triceps brachii steaks as a substitute for gluteus medius steaks in foodservice and retail applications, including the impact of aging time and USDA quality grade on the palatability of both muscles. Top sirloin butts (n = 600) and shoulder clod arm ...

  20. Application of Hydrogel in Reconstruction Surgery: Hydrogel/Fat Graft Complex Filler for Volume Reconstruction in Critical Sized Muscle Defects

    PubMed Central

    Ip, W. Y.

    2016-01-01

    Autogenic fat graft usually suffers from degeneration and volume shrinkage in volume reconstruction applications. How to maintain graft viability and graft volume is an essential consideration in reconstruction therapies. In this presented investigation, a new fat graft transplantation method was developed aiming to improve long term graft viability and volume reconstruction effect by incorporation of hydrogel. The harvested fat graft is dissociated into small fragments and incorporated into a collagen based hydrogel to form a hydrogel/fat graft complex for volume reconstruction purpose. In vitro results indicate that the collagen based hydrogel can significantly improve the survivability of cells inside isolated graft. In a 6-month investigation on artificial created defect model, this hydrogel/fat graft complex filler has demonstrated the ability of promoting fat pad formation inside the targeted defect area. The newly generated fat pad can cover the whole defect and restore its original dimension in 6-month time point. Compared to simple fat transplantation, this hydrogel/fat graft complex system provides much improvement on long term volume restoration effect against degeneration and volume shrinkage. One notable effect is that there is continuous proliferation of adipose tissue throughout the 6-month period. In summary, the hydrogel/fat graft system presented in this investigation demonstrated a better and more significant effect on volume reconstruction in large sized volume defect than simple fat transplantation. PMID:27446947

  1. Comparison of Muscle Fiber and Meat Quality Characteristics in Different Japanese Quail Lines

    PubMed Central

    Choi, Y. M.; Hwang, S.; Lee, K.

    2016-01-01

    The aim of this study was to compare the growth performance, fiber characteristics of the pectoralis major muscle, and meat quality characteristics in the heavy weight (HW) and random bred control (RBC) quail lines and genders. The HW male exhibited more than two times greater body (245.7 vs 96.1 g, p<0.05) and pectoralis major muscle (PMW; 37.1 vs 11.1 g, p<0.05) weights compared to the RBC female. This growth performance in the HW line was associated with a greater muscle fiber area (1,502 vs 663.0 μm2, p<0.001) compared to the RBC line. Greater muscle mass of the HW male was accompanied by a higher percentage of type IIB fiber compared to the HW female (64.0% vs 51.0%, p<0.05). However, muscle fiber hyperplasia (increase in fiber number) has had a somewhat limited effect on PMW between the two lines. On the other hand, the HW line harboring a higher proportion of type IIB fiber showed rapid pH decline at the early postmortem period (6.23 vs 6.41, p<0.05) and lighter meat surface (53.5 vs 47.3, p<0.05) compared to the RBC line harboring a lower proportion of type IIB fiber. There were no significant differences observed in the measurement of water-holding capacity including drip loss (2.74% vs 3.07%, p>0.05) and cooking loss (21.9% vs 20.4%, p>0.05) between the HW and RBC lines. Therefore, the HW quail line developed by selection from the RBC quail, was slightly different in the meat quality characteristics compared to the RBC line, and a marked difference was found in growth performance between the two quail lines. PMID:27383804

  2. 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.

  3. Comparison of Blepharoptosis Correction Using Müller-aponeurosis Composite Flap Advancement and Frontalis Muscle Transfer

    PubMed Central

    Ramadhan, Anwar; Han, Dong Gil; Shim, Jeong Su; Lee, Yong Jig; Ha, Won Ho; Lee, Byung Kwon

    2014-01-01

    Background: Treatments for severe blepharoptosis are well documented and include the most common operations for restoring upper eyelid ptosis, which are levator surgery and frontal muscle transfers; however, the choice of treatment is still controversial. There are different approaches to the restoration of upper eyelid ptosis, and the choice will be based on ptosis severity and the surgeon’s skill and experience. Methods: Two hundred and fourteen patients presenting with a levator function of between 2 and 4 mm received ptosis correction between 1991 and 2010 at our clinic. Of these, 71 patients underwent Müller aponeurosis composite flap advancement for correction of 89 eyelids, and frontalis muscle transfer was performed on 143 patients (217 eyelids). Postoperative results were evaluated with an average follow-up period of 23 months. Results: The preoperative average for marginal reflex distance (MRD1) in the Müller aponeurosis composite flap advancement group was 1.25 mm, and in the frontal muscle transfer group, it was 0.59 mm. The area of corneal exposure (ACE) was 57.2% in the Müller aponeurosis composite flap advancement group and 53.6% in the frontal muscle transfer group. The postoperative average distance was not significantly different for the 2 techniques. In the Müller aponeurosis composite flap advancement group, MRD1 was 2.7 mm and ACE was improved to 73.5%. In the frontal muscle transfer group, MRD1 was 2.3 mm and ACE was 71.2%. Undercorrection and eyelid asymmetry were the most frequently observed postoperative complications for both techniques. Conclusions: In our study, we confirmed that Müller aponeurosis composite flap advancement and the frontalis transfer technique are both effective in the correction of severe blepharoptosis; our results showed no significant differences between the 2 techniques. PMID:25426383

  4. Comparison of Mitochondrial Reactive Oxygen Species Production of Ectothermic and Endothermic Fish Muscle

    PubMed Central

    Wiens, Lilian; Banh, Sheena; Sotiri, Emianka; Jastroch, Martin; Block, Barbara A.; Brand, Martin D.; Treberg, Jason R.

    2017-01-01

    Recently we demonstrated that the capacity of isolated muscle mitochondria to produce reactive oxygen species, measured as H2O2 efflux, is temperature-sensitive in isolated muscle mitochondria of ectothermic fish and the rat, a representative endothermic mammal. However, at physiological temperatures (15° and 37°C for the fish and rat, respectively), the fraction of total mitochondrial electron flux that generated H2O2, the fractional electron leak (FEL), was far lower in the rat than in fish. Those results suggested that the elevated body temperatures associated with endothermy may lead to a compensatory decrease in mitochondrial ROS production relative to respiratory capacity. To test this hypothesis we compare slow twitch (red) muscle mitochondria from the endothermic Pacific bluefin tuna (Thunnus orientalis) with mitochondria from three ectothermic fishes [rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio), and the lake sturgeon (Acipenser fulvescens)] and the rat. At a common assay temperature (25°C) rates of mitochondrial respiration and H2O2 efflux were similar in tuna and the other fishes. The thermal sensitivity of fish mitochondria was similar irrespective of ectothermy or endothermy. Comparing tuna to the rat at a common temperature, respiration rates were similar, or lower depending on mitochondrial substrates. FEL was not different across fish species at a common assay temperature (25°C) but was markedly higher in fishes than in rat. Overall, endothermy and warming of Pacific Bluefin tuna red muscle may increase the potential for ROS production by muscle mitochondria but the evolution of endothermy in this species is not necessarily associated with a compensatory reduction of ROS production relative to the respiratory capacity of mitochondria. PMID:28966595

  5. Comparison of Mitochondrial Reactive Oxygen Species Production of Ectothermic and Endothermic Fish Muscle.

    PubMed

    Wiens, Lilian; Banh, Sheena; Sotiri, Emianka; Jastroch, Martin; Block, Barbara A; Brand, Martin D; Treberg, Jason R

    2017-01-01

    Recently we demonstrated that the capacity of isolated muscle mitochondria to produce reactive oxygen species, measured as H2O2 efflux, is temperature-sensitive in isolated muscle mitochondria of ectothermic fish and the rat, a representative endothermic mammal. However, at physiological temperatures (15° and 37°C for the fish and rat, respectively), the fraction of total mitochondrial electron flux that generated H2O2, the fractional electron leak (FEL), was far lower in the rat than in fish. Those results suggested that the elevated body temperatures associated with endothermy may lead to a compensatory decrease in mitochondrial ROS production relative to respiratory capacity. To test this hypothesis we compare slow twitch (red) muscle mitochondria from the endothermic Pacific bluefin tuna (Thunnus orientalis) with mitochondria from three ectothermic fishes [rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio), and the lake sturgeon (Acipenser fulvescens)] and the rat. At a common assay temperature (25°C) rates of mitochondrial respiration and H2O2 efflux were similar in tuna and the other fishes. The thermal sensitivity of fish mitochondria was similar irrespective of ectothermy or endothermy. Comparing tuna to the rat at a common temperature, respiration rates were similar, or lower depending on mitochondrial substrates. FEL was not different across fish species at a common assay temperature (25°C) but was markedly higher in fishes than in rat. Overall, endothermy and warming of Pacific Bluefin tuna red muscle may increase the potential for ROS production by muscle mitochondria but the evolution of endothermy in this species is not necessarily associated with a compensatory reduction of ROS production relative to the respiratory capacity of mitochondria.

  6. High, but not low exercise volume, shifts the balance of renin angiotensin system towards ACE2/Mas receptor axis in skeletal muscle in obese rats.

    PubMed

    Frantz, Eliete Dalla Corte; Giori, Isabele Gomes; Machado, Marcus Vinícius; Magliano, D'Angelo Carlo; Freitas, Fernanda Marques; Andrade, Mariana Sodré Boêta; Vieira, Aline Bomfim; Claudio Lucas da Nóbrega, Antonio; Tibirica, Eduardo

    2017-07-05

    Metabolic Syndrome (MS) is a cluster of metabolic risk factors which is linked to central obesity, elevated blood pressure, insulin resistance (IR) and dyslipidemia, where the rennin-angiotensin system (RAS) may provide a link among them. This study aimed to evaluate volume exercise effects comparing low versus high volume of chronic aerobic exercise on RAS axes in skeletal muscle in a diet-induced obesity (DIO) rat model. For this, male Wistar-Kyoto rats were fed a standard chow diet (SC) or a high-fat diet (HF) for 32 weeks. Animals receiving the HF diet were randomly divided into low exercise volume (LEV, 150 min.week(-1)) and high exercise volume (HEV, 300 min.week(-1)) at the 20(th) week. After 12 weeks of aerobic treadmill training the body mass and composition, blood pressure, glucose and lipid metabolism, RAS axes, insulin signaling and inflammatory pathway were performed. HEV slowed the body mass gain, reduced intra-abdominal fat pad and leptin levels, improved total and peripheral body composition and inflammatory cytokine, reduced AT1R expression and increased Mas receptor protein expression compared with the HF animals. Sedentary groups (SC and HF) presented lower time to exhaustion and maximal velocity compared with the LEV and HEV groups. The both exercise training groups showed reduced resting systolic blood pressure and heart rate, improved glucose tolerance, IR, insulin signaling and lipid profile. We conclude that the HEV, but not LEV, shifted the balance of RAS towards the ACE2/Mas receptor axis in skeletal muscle, presenting protective effects against DIO model. Copyright © 2017, American Journal of Physiology-Endocrinology and Metabolism.

  7. Comparison between Variable and Conventional Volume-Controlled Ventilation on Cardiorespiratory Parameters in Experimental Emphysema.

    PubMed

    Henriques, Isabela; Padilha, Gisele A; Huhle, Robert; Wierzchon, Caio; Miranda, Paulo J B; Ramos, Isalira P; Rocha, Nazareth; Cruz, Fernanda F; Santos, Raquel S; de Oliveira, Milena V; Souza, Sergio A; Goldenberg, Regina C; Luiz, Ronir R; Pelosi, Paolo; de Abreu, Marcelo G; Silva, Pedro L; Rocco, Patricia R M

    2016-01-01

    Emphysema is characterized by loss of lung tissue elasticity and destruction of structures supporting alveoli and capillaries. The impact of mechanical ventilation strategies on ventilator-induced lung injury (VILI) in emphysema is poorly defined. New ventilator strategies should be developed to minimize VILI in emphysema. The present study was divided into two protocols: (1) characterization of an elastase-induced emphysema model in rats and identification of the time point of greatest cardiorespiratory impairment, defined as a high specific lung elastance associated with large right ventricular end-diastolic area; and (2) comparison between variable (VV) and conventional volume-controlled ventilation (VCV) on lung mechanics and morphometry, biological markers, and cardiac function at that time point. In the first protocol, Wistar rats (n = 62) received saline (SAL) or porcine pancreatic elastase (ELA) intratracheally once weekly for 4 weeks, respectively. Evaluations were performed 1, 3, 5, or 8 weeks after the last intratracheal instillation of saline or elastase. After identifying the time point of greatest cardiorespiratory impairment, an additional 32 Wistar rats were randomized into the SAL and ELA groups and then ventilated with VV or VCV (n = 8/group) [tidal volume (VT) = 6 mL/kg, positive end-expiratory pressure (PEEP) = 3 cmH2O, fraction of inspired oxygen (FiO2) = 0.4] for 2 h. VV was applied on a breath-to-breath basis as a sequence of randomly generated VT values (mean VT = 6 mL/kg), with a 30% coefficient of variation. Non-ventilated (NV) SAL and ELA animals were used for molecular biology analysis. The time point of greatest cardiorespiratory impairment, was observed 5 weeks after the last elastase instillation. At this time point, interleukin (IL)-6, cytokine-induced neutrophil chemoattractant (CINC)-1, amphiregulin, angiopoietin (Ang)-2, and vascular endothelial growth factor (VEGF) mRNA levels were higher in ELA compared to SAL. In ELA animals

  8. Comparison between Variable and Conventional Volume-Controlled Ventilation on Cardiorespiratory Parameters in Experimental Emphysema

    PubMed Central

    Henriques, Isabela; Padilha, Gisele A.; Huhle, Robert; Wierzchon, Caio; Miranda, Paulo J. B.; Ramos, Isalira P.; Rocha, Nazareth; Cruz, Fernanda F.; Santos, Raquel S.; de Oliveira, Milena V.; Souza, Sergio A.; Goldenberg, Regina C.; Luiz, Ronir R.; Pelosi, Paolo; de Abreu, Marcelo G.; Silva, Pedro L.; Rocco, Patricia R. M.

    2016-01-01

    Emphysema is characterized by loss of lung tissue elasticity and destruction of structures supporting alveoli and capillaries. The impact of mechanical ventilation strategies on ventilator-induced lung injury (VILI) in emphysema is poorly defined. New ventilator strategies should be developed to minimize VILI in emphysema. The present study was divided into two protocols: (1) characterization of an elastase-induced emphysema model in rats and identification of the time point of greatest cardiorespiratory impairment, defined as a high specific lung elastance associated with large right ventricular end-diastolic area; and (2) comparison between variable (VV) and conventional volume-controlled ventilation (VCV) on lung mechanics and morphometry, biological markers, and cardiac function at that time point. In the first protocol, Wistar rats (n = 62) received saline (SAL) or porcine pancreatic elastase (ELA) intratracheally once weekly for 4 weeks, respectively. Evaluations were performed 1, 3, 5, or 8 weeks after the last intratracheal instillation of saline or elastase. After identifying the time point of greatest cardiorespiratory impairment, an additional 32 Wistar rats were randomized into the SAL and ELA groups and then ventilated with VV or VCV (n = 8/group) [tidal volume (VT) = 6 mL/kg, positive end-expiratory pressure (PEEP) = 3 cmH2O, fraction of inspired oxygen (FiO2) = 0.4] for 2 h. VV was applied on a breath-to-breath basis as a sequence of randomly generated VT values (mean VT = 6 mL/kg), with a 30% coefficient of variation. Non-ventilated (NV) SAL and ELA animals were used for molecular biology analysis. The time point of greatest cardiorespiratory impairment, was observed 5 weeks after the last elastase instillation. At this time point, interleukin (IL)-6, cytokine-induced neutrophil chemoattractant (CINC)-1, amphiregulin, angiopoietin (Ang)-2, and vascular endothelial growth factor (VEGF) mRNA levels were higher in ELA compared to SAL. In ELA animals

  9. KEY COMPARISON: Final report on EUROMET key comparison EUROMET.M.FF-K4 for volume intercomparison of 100 ml Gay-Lussac pycnometer

    NASA Astrophysics Data System (ADS)

    Batista, Elsa

    2006-01-01

    Pycnometers are currently used for the measurement of the density of different liquids (from water to high viscosity inks). In order to have a correct density measurement the volume of the pycnometer must be obtained by calibration. Usually the calibration method is a gravimetric method. In 2002 a project for the comparison of the volume of 100 ml Gay-Lussac pycnometer was initially proposed in the EUROMET TC Flow. Fourteen NMIs agreed to participate and the EUROMET 692 project started officially in September 2002 and was concluded in March 2004. The main purpose of the project was to compare the experimental method and the uncertainty calculation in the pycnometer volume determination and it was expected to be representative for all types of laboratory glassware. In the EUROMET TC Flow 2006 in Lisbon it was decided to propose this project as a EUROMET Key Comparison due to the good overall agreement found. It was therefore necessary to link the EUROMET 692 results with the Key Comparison CCM.FF-K4. Because the pycnometers were not identical in both intercomparisons, some calculations on equivalence were performed based on BIPM rules. The results of all laboratories participating in EUROMET project 692 are presented in this report as well as their equivalence with the reference value of the key comparison CCM.FF-K4. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  10. [The comparison of volume of ischemia zone in CT examination with neurological and functional status of patients after cerebral ischemia].

    PubMed

    Bartynowska, Karolina

    2013-01-01

    The aim of this work was to establish the correlation between volume of ischemic zone in CT examination and neurological and functional (Barthel index) disorders after cerebral ischemia. The retrospective study was performed. The 30 patients (the median age was 73 years; 14 woman and 16 man) were examined. The medial cerebral artery stroke was recognised in CT. CT examinations without contrast media injection, neurological and functional (Barthel index) diagnostic tests were performed directly and 18 months after ischemia. The evolution of ischemic zone in CT and neurological and functional disorders were estimated. The correlation between volume of ischemic zone in CT, neurological parameters and Barthel index results was examined. The statistical correlation between ischemic zone volumetry and physiological reactions was ascertained. In acute phase the greater volume of ischemic zone responds to neurological dysfunctions. The same tendency, without statistical significance, was observed between volume of ischemic zone and Barthel index result (inversely proportional). 18 months after cerebral stroke the statistical correlation was significant only for comparison of volume of the ischemic zone and Barthel index result. The greater volume of ischemic zone responded to lower Barthel index. Ischemic stroke volumetry in CT examination can facilitate neurological (physiological reactions disorders) and functional (Barthel index) status assessment.

  11. Open versus percutaneous instrumentation in thoracolumbar fractures: magnetic resonance imaging comparison of paravertebral muscles after implant removal.

    PubMed

    Ntilikina, Yves; Bahlau, David; Garnon, Julien; Schuller, Sébastien; Walter, Axel; Schaeffer, Mickaël; Steib, Jean-Paul; Charles, Yann Philippe

    2017-08-01

    OBJECTIVE Percutaneous instrumentation in thoracolumbar fractures is intended to decrease paravertebral muscle damage by avoiding dissection. The aim of this study was to compare muscles at instrumented levels in patients who were treated by open or percutaneous surgery. METHODS Twenty-seven patients underwent open instrumentation, and 65 were treated percutaneously. A standardized MRI protocol using axial T1-weighted sequences was performed at a minimum 1-year follow-up after implant removal. Two independent observers measured cross-sectional areas (CSAs, in cm(2)) and region of interest (ROI) signal intensity (in pixels) of paravertebral muscles by using OsiriX at the fracture level, and at cranial and caudal instrumented pedicle levels. An interobserver comparison was made using the Bland-Altman method. Reference ROI muscle was assessed in the psoas and ROI fat subcutaneously. The ratio ROI-CSA/ROI-fat was compared for patients treated with open versus percutaneous procedures by using a linear mixed model. A linear regression analyzed additional factors: age, sex, body mass index (BMI), Pfirrmann grade of adjacent discs, and duration of instrumentation in situ. RESULTS The interobserver agreement was good for all CSAs. The average CSA for the entire spine was 15.7 cm(2) in the open surgery group and 18.5 cm(2) in the percutaneous group (p = 0.0234). The average ROI-fat and ROI-muscle signal intensities were comparable: 497.1 versus 483.9 pixels for ROI-fat and 120.4 versus 111.7 pixels for ROI-muscle in open versus percutaneous groups. The ROI-CSA varied between 154 and 226 for open, and between 154 and 195 for percutaneous procedures, depending on instrumented levels. A significant difference of the ROI-CSA/ROI-fat ratio (0.4 vs 0.3) was present at fracture levels T12-L1 (p = 0.0329) and at adjacent cranial (p = 0.0139) and caudal (p = 0.0100) instrumented levels. Differences were not significant at thoracic levels. When adjusting based on age, BMI, and

  12. High muscle mitochondrial volume and aerobic capacity in a small marsupial (Sminthopsis crassicaudata) reveals flexible links between energy-use levels in mammals.

    PubMed

    Dawson, Terence J; Webster, Koa N; Lee, Enhua; Buttemer, William A

    2013-04-01

    We investigated the muscle structure-function relationships that underlie the aerobic capacity of an insectivorous, small (~15 g) marsupial, Sminthopsis crassicaudata (Family: Dasyuridae), to obtain further insight into energy use patterns in marsupials relative to those in placentals, their sister clade within the Theria (advanced mammals). Disparate hopping marsupials (Suborder Macropodiformes), a kangaroo (Macropus rufus) and a rat-kangaroo (Bettongia penicillata), show aerobic capabilities as high as those of 'athletic' placentals. Equivalent muscle mitochondrial volumes and cardiovascular features support these capabilities. We examined S. crassicaudata to determine whether highly developed aerobic capabilities occur elsewhere in marsupials, rather than being restricted to the more recently evolved Macropodiformes. This was the case. Treadmill-trained S. crassicaudata attained a maximal aerobic metabolic rate ( or MMR) of 272 ml O2 min(-1) kg(-1) (N=8), similar to that reported for a small (~20 g), 'athletic' placental, Apodemus sylvaticus, 264 ml O2 min(-1) kg(-1). Hopping marsupials have comparable aerobic levels when body mass variation is considered. Sminthopsis crassicaudata has a basal metabolic rate (BMR) about 75% of placental values but it has a notably large factorial aerobic scope (fAS) of 13; elevated fAS also features in hopping marsupials. The of S. crassicaudata was supported by an elevated total muscle mitochondrial volume, which was largely achieved through high muscle mitochondrial volume densities, Vv(mt,f), the mean value being 14.0±1.33%. These data were considered in relation to energy use levels in mammals, particularly field metabolic rate (FMR). BMR is consistently lower in marsupials, but this is balanced by a high fAS, such that marsupial MMR matches that of placentals. However, FMR shows different mass relationships in the two clades, with the FMR of small (<125 g) marsupials, such as S. crassicaudata, being higher than that in

  13. Comparison Between Multicopter Uav and Total Station for Estimating Stockpile Volumes

    NASA Astrophysics Data System (ADS)

    Arango, C.; Morales, C. A.

    2015-08-01

    Currently the UAV (Unmanned Aerial Vehicle) have become an alternative for different engineering applications, especially in surveying, one of these applications is the calculation of volumes of stockpiled material, but there are questions about its accuracy and efficiency, the purpose of this article is to compare traditional surveying methods for estimating total volumes through data obtained by total stations and data obtained by a multicopter UAV. In order to answer these questions we obtain data from the same location and the results were compared. After comparing the results it was found that there was a 2,88% difference between the volume calculated with the total station data and the actual volume, and -0,67% difference between the volume calculated with the UAV data and the actual volume, concluding that the estimated volume with UAV data is more accurate.

  14. Comparison of the subunit structure of acetylcholine receptors from muscle and electric organ of Electrophorus electricus.

    PubMed

    Gullick, W J; Lindstrom, J M

    1983-08-02

    The acetylcholine receptors of the electric organ and muscle tissues of Electrophorus electricus are composed of alpha, beta, gamma, and delta subunits. Receptor subunits from the two tissues were compared by peptide mapping with monoclonal antibodies, an affinity-labeling reagent, and a lectin to characterize particular peptide fragments. These experiments indicate that the corresponding receptor subunits from the two tissues are extensively homologous or identical throughout their amino acid sequences. Small differences in the electrophoresis of peptide fragments of alpha subunits between the two tissues occurred on fragments which bound labeled lectin. These results suggest that the acetylcholine receptors in electric organ and muscle tissues of Electrophorus differ in structure only by minor posttranslational modifications perhaps involving carbohydrate.

  15. Comparison of psychologic and physiologic functioning between patients with masticatory muscle pain and matched controls.

    PubMed

    Carlson, C R; Okeson, J P; Falace, D A; Nitz, A J; Curran, S L; Anderson, D

    1993-01-01

    This study explored the physiologic and psychologic distinctions between masticatory muscle pain patients and age and sex-matched normal controls. Subjects completed several standardized psychologic tests. They then underwent a laboratory stress profile evaluation to obtain physiologic measures (EMG, heart rate, systolic and diastolic blood pressure) under conditions of rest, mental stress, and relaxation. The pain patients reported greater anxiety, especially cognitive symptoms, and feelings of muscle tension than did the controls. Under stress, pain patients had higher heart rates and systolic blood pressure than the controls. Electromyogram activity in the masseter regions was not significantly different between the pain and control group. The results are discussed in terms of the likely mechanisms that might account for the observed differences between masticatory pain patients and normal subjects.

  16. [Comparison of force and shortening velocity in fast and slow rabbit muscle fibers at different temperatures].

    PubMed

    Kochubeĭ, P V; Bershitskiĭ, S Iu

    2014-01-01

    The temperature dependence of force, maximal shortening velocity and power of maximally activated single permeabilized fibers from fast and slow muscles of the rabbit were recorded in a temperature range from 10 to 35 degrees C with 5 degrees C step. It was found that temperature dependence of force of both types of fibers is identical. Averaged maximal shortening velocity in the slow fibers, unlike the fast fibers, had no statistically significant temperature dependence that is not in agreement with the data obtained on intact rat muscle fibers and in an in vitro motility assay. However maximal shortening velocity in each individual slow fiber did depend on temperature. The temperature dependence of power of the slow fibers was lower than that of the fast ones. Because of large data scattering the average temperature dependence of power of the slow fibers was significantly lower than that in individual slow fibers.

  17. Excluded Volume Effects in Polymer Solutions: II. Comparison of Experimental Results with Numerical Simulation Data

    SciTech Connect

    Graessley, W.W.; Grest, G.S.; Hayward, R.C.

    1999-03-23

    The effect of excluded volume on the coil size of dilute linear polymers was investigated by off-lattice Monte Carlo simulations. The radius of gyration R{sub g} was evaluated for a wide range of chain lengths at several temperatures and at the athermal condition. The theta temperature and the corresponding theta chain dimensions were established for the system, and the dependence of the size expansion factor, a{sub s} = R{sub g} /(R{sub g}){sub {theta}}, on chain length N and temperature T was examined. For long chains and at high temperatures, a{sub s} is a function of N/N{sub s}{sup 2} alone, where the length scale N{sub s}{sup 2} depends only on T. The form of this simulations-based master function compares favorably with {alpha}{sub s}(M/M{sub s}{sup 2}), an experimental master curve for linear polymers in good solvents, where M{sub s}{sup 2} depends only on polymer-solvent system. Comparisons when N{sub s}{sup 2}(T) and M{sub s}{sup 2}(system) are reduced to common units, numbers of Kuhn steps, strongly indicate that coil expansion in even the best of good solvents is small relative to that expected for truly athermal solutions. An explanation for this behavior is proposed, based on what would appear to be an inherent difference in the equation of state properties for polymeric and monomeric liquids.

  18. Comparison of reduction of edema after rest and after muscle exercises in treatment of chronic venous insufficiency

    PubMed Central

    Quilici, Belczak Cleusa Ema; Gildo, Cavalheri; de Godoy, Jose Maria Pereira; Quilici, Belczak Sergio; Augusto, Caffaro Roberto

    2009-01-01

    Aim The aim of this work was to compare the reduction in edema obtained in the conservative treatment of phlebopathies after resting and after performing a muscle exercise program in the Trendelenburg position. Methods Twenty-eight limbs of 24 patients with venous edema of distinct etiologies and classified as between C3 and C5 using CEAP classification. Volumetric evaluation by water displacement was carried out before and after resting in the Trendelenburg position and after performing programmed muscle exercises 24 hours later under identical conditions of time, position and temperature. For the statistical analysis the paired t-test was used with an alpha error of 5% being considered acceptable. Results The average total volume of the lower limbs was 3,967.46 mL. The mean reduction in edema obtained after resting was 92.9 mL, and after exercises it was 135.4 mL, giving a statistically significant difference (p-value = 0.0007). Conclusion In conclusion, exercises are more efficient to reduce the edema of lower limbs than resting in the Trendelenburg position. PMID:19602249

  19. Abnormal pulmonary function and respiratory muscle strength findings in Chinese patients with Parkinson's disease and multiple system atrophy--comparison with normal elderly.

    PubMed

    Wang, Yao; Shao, Wei-bo; Gao, Li; Lu, Jie; Gu, Hao; Sun, Li-hua; Tan, Yan; Zhang, Ying-dong

    2014-01-01

    There have been limited comparative data regarding the investigations on pulmonary and respiratory muscle function in the patients with different parkinsonism disorders such as Parkinson's disease (PD) and multiple system atrophy (MSA) versus normal elderly. The present study is aiming to characterize the performance of pulmonary function and respiratory muscle strength in PD and MSA, and to investigate the association with severity of motor symptoms and disease duration. Pulmonary function and respiratory muscle strength tests were performed in 30 patients with PD, 27 with MSA as well as in 20 age-, sex-, height-, weight-matched normal elderly controls. All the patients underwent United Parkinson's disease rating scale (UPDRS) or united multiple system atrophy rating scale (UMSARS) separately as diagnosed. Vital capacity, forced expiratory volume in 1 second and forced vital capacity decreased, residual volume and ratio of residual volume to total lung capacity increased in both PD and MSA groups compared to controls (p<0.05). Diffusing capacity was decreased in the MSA group, compared with PD and normal elderly control groups (p<0.05). Respiratory muscle strength was lower in both PD and MSA groups than in controls (p<0.05). The values representing spirometry function and respiratory muscle strength were found to have a negative linear correlation with mean score of UPDRS-III in PD and mean score of UMSARS-I in MSA. Respiratory muscle strength showed a negative linear correlation with the mean score of UMSARS-II and disease duration in MSA patients. These findings suggest that respiratory dysfunction is involved in PD and MSA. Respiratory muscle strength is remarkably reduced, and some of the parameters correlate with disease duration and illness severity. The compromised respiratory function in neurodegenerative disorders should be the focus of further researches.

  20. Children and adults minimise activated muscle volume by selecting gait parameters that balance gross mechanical power and work demands

    PubMed Central

    Hubel, Tatjana Y.; Usherwood, James R.

    2015-01-01

    ABSTRACT Terrestrial locomotion on legs is energetically expensive. Compared with cycling, or with locomotion in swimming or flying animals, walking and running are highly uneconomical. Legged gaits that minimise mechanical work have previously been identified and broadly match walking and running at appropriate speeds. Furthermore, the ‘cost of muscle force’ approaches are effective in relating locomotion kinetics to metabolic cost. However, few accounts have been made for why animals deviate from either work-minimising or muscle-force-minimising strategies. Also, there is no current mechanistic account for the scaling of locomotion kinetics with animal size and speed. Here, we report measurements of ground reaction forces in walking children and adult humans, and their stance durations during running. We find that many aspects of gait kinetics and kinematics scale with speed and size in a manner that is consistent with minimising muscle activation required for the more demanding between mechanical work and power: spreading the duration of muscle action reduces activation requirements for power, at the cost of greater work demands. Mechanical work is relatively more demanding for larger bipeds – adult humans – accounting for their symmetrical M-shaped vertical force traces in walking, and relatively brief stance durations in running compared with smaller bipeds – children. The gaits of small children, and the greater deviation of their mechanics from work-minimising strategies, may be understood as appropriate for their scale, not merely as immature, incompletely developed and energetically sub-optimal versions of adult gaits. PMID:26400978

  1. Comparison of human bronchiolar smooth muscle responsiveness in vitro with histological signs of inflammation.

    PubMed Central

    de Jongste, J C; Mons, H; Van Strik, R; Bonta, I L; Kerrebijn, K F

    1987-01-01

    A study was carried out to test the hypothesis that chronic inflammation is associated with increased sensitivity or contractility of human airway smooth muscle. Bronchiolar strips from 30 patients, 12 of whom had chronic bronchitis, were examined in the organ bath for their responses to histamine, methacholine, and leukotriene (LT) C4. The same airways were also studied histologically and small airway disease was quantified by subjective grading of the degree of inflammatory cell infiltration, smooth muscle hypertrophy, fibrosis, and goblet cell hyperplasia. The degree of small airway disease varied widely among patients both with and without chronic bronchitis. Multiple regression analysis failed to show increased sensitivity (-log EC50) to histamine, methacholine, or LTC4 in relation to small airway disease. In contrast, the only significant correlations found were between a decreased -log EC50 to histamine and methacholine and an increased small airway disease score. Contractile responses (Tmax) to histamine and methacholine in peripheral airways tended to be higher in patients with chronic bronchitis than in those without. Tmax was not related to small airway disease scores. These results suggest that chronic airway inflammation does not cause in vitro hyperresponsiveness of human small airway smooth muscle. Images PMID:3321543

  2. Comparison of Contraction Rates of Abdominal Muscles of Chronic Low Back Pain Patients in Different Postures

    PubMed Central

    Cho, Sung-Hak; Kim, Kang Hoon; Baek, Il-Hun; Goo, Bong-Oh

    2013-01-01

    [Purpose] This study examined the contraction rates of abdominal muscles in relation to the posture of chronic lumbar pain patients and normal subjects. [Subjects] The subjects were 17 chronic low back pain (CLBP) patients and 17 normal people between the ages of 20 and 59. [Methods] Experimental postures included a supine position, a sitting position, and a standing position. Measurements were taken at rest and during abdominal contraction. The measurement at rest was taken during expiration with comfortable breathing, and the measurement during contraction was taken at maximum expiration of forced expiration. Muscle contraction rates (on contraction and at relaxation) were calculated. [Results] There were significant differences between CLBP patients and normal subjects in the transversus abdominis (TrA) in the standing position. [Conclusion] Changes in contraction rates of the abdominal muscles of normal subjects and CLBP patients were examined in different postures at maximum expiration. It was found that the contraction rate of TrA in CLBP patients in a standing position, is significantly lower than that of normal subjects. PMID:24259882

  3. Normalizing surface electromyographic measures of the masticatory muscles: Comparison of two different methods for clinical purpose.

    PubMed

    Mapelli, Andrea; Tartaglia, Gianluca Martino; Connelly, Stephen Thaddeus; Ferrario, Virgilio Ferruccio; De Felicio, Claudia Maria; Sforza, Chiarella

    2016-10-01

    To compare a new normalization technique (wax pad, WAX) with the currently utilized cotton roll (COT) method in surface electromyography (sEMG) of the masticatory muscles. sEMG of the masseter and anterior temporalis muscles of 23 subjects was recorded while performing two repetitions of 5s maximum voluntary clenches (MVC) on COT and WAX. For each task, the mean value of sEMG amplitude and its coefficient of variation were calculated, and the differences between the two repetitions computed. The standard error of measurement (SEM) was calculated. For each subject and muscle, the COT-to-WAX maximum activity increment was computed. Participant preference between tasks was also recorded. WAX MVC tasks had larger maximum EMG amplitude than COT MVC tasks (P<0.001), with COT-to-WAX maximum amplitude increments of 61% (temporalis) and 94% (masseter) (P=0.006). WAX MVC had better test-retest repeatability than COT. For both MVC modalities, the mean amplitude (P>0.391) and its coefficient of variation were unchanged (P>0.180). The WAX task was the more comfortable for 18/23 subjects (P=0.007). WAX normalization ensures the same stability level of maximum EMG amplitude as COT normalization, but it is more repeatable, elicits larger maximum muscular contraction, and is felt to be more comfortable by subjects. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Transient kinetics of Ca2+ transport of sarcoplasmic reticulum. A comparison of cardiac and skeletal muscle.

    PubMed

    Sumida, M; Wang, T; Mandel, F; Froehlich, J P; Schwartz, A

    1978-12-25

    Current evidence supports similar functions and mechanisms for cardiac sarcoplasmic reticulum (CSR) as for skeletal sarcoplasmic reticulum (SSR). It is thought that the slower relaxation rate of cardiac muscle compared to fast skeletal muscle reflects the lower ATPase activity and calcium transport of CSR. Possible quantitative differences is phosphorylation, dephosphorylation, and calcium transport of the isolated preparations are studied using a quench-flow apparatus. The results show that both CSR and SSR bind calcium tightly in the absence of ATP, and coupling of E approximately P formation and calcium transport occurs in the transient phase of ATP hydrolysis. The rate of phosphorylation (t-1/2 - 10 ms) of sarcoplasmic reticulum (SR) preloaded with calcium is the same for cardiac and skeletal preparations. However, the rates of dissociation of extra vesicular calcium (10 s-1 versus 15 s-1), phosphorylation of calcium-free SR, and dephosphorylation of E approximately P (8 s-1 versus 12 s-1) are lower for CSR than for SSR. By computer simulation, the apparent rate constants associated with the reduced rates of phosphorylation of calcium-free SR were: 12 s-1 for CSR and 63 s-1 for SSR in the presence of high Mg2+. The difference in the rates may be partly responsible for the lower levels of ATPase and calcium transport activity with characterize cardiac muscle preparations.

  5. A Comparison of Total and Intrinsic Muscle Stiffness Among Flexors and Extensors of the Ankle, Knee and Elbow

    NASA Technical Reports Server (NTRS)

    Lemoine, Sandra M.

    1997-01-01

    This study examined 3 methods that assessed muscle stiffness. Muscle stiffness has been quantified by tissue reactive force (transverse stiffness), vibration, and force (or torque) over displacement. Muscle stiffness also has two components: reflex (due to muscle sensor activity) and intrinsic (tonic firing of motor units, elastic nature of actin and myosin cross bridges, and connective tissue). This study compared three methods of measuring muscle stiffness of agonist-antagonist muscle pairs of the ankle, knee and elbow.

  6. A Comparison of Total and Intrinsic Muscle Stiffness Among Flexors and Extensors of the Ankle, Knee and Elbow

    NASA Technical Reports Server (NTRS)

    Lemoine, Sandra M.

    1997-01-01

    This study examined 3 methods that assessed muscle stiffness. Muscle stiffness has been quantified by tissue reactive force (transverse stiffness), vibration, and force (or torque) over displacement. Muscle stiffness also has two components: reflex (due to muscle sensor activity) and intrinsic (tonic firing of motor units, elastic nature of actin and myosin cross bridges, and connective tissue). This study compared three methods of measuring muscle stiffness of agonist-antagonist muscle pairs of the ankle, knee and elbow.

  7. Comparison of different volumes of high intensity interval training on cardiac autonomic function in sedentary young women.

    PubMed

    Bhati, Pooja; Bansal, Vishal; Moiz, Jamal Ali

    2017-08-24

    Purpose The present study was conducted to compare the effects of low volume of high intensity interval training (LVHIIT) and high volume of high intensity interval training (HVHIIT) on heart rate variability (HRV) as a primary outcome measure, and on maximum oxygen consumption (VO2max), body composition, and lower limb muscle strength as secondary outcome measures, in sedentary young women. Methods Thirty-six participants were recruited in this study. The LVHIIT group (n = 17) performed one 4-min bout of treadmill running at 85%-95% maximum heart rate (HRmax), followed by 3 min of recovery by running at 70% HRmax, three times per week for 6 weeks. The HVHIIT group (n = 15) performed four times 4-min bouts of treadmill running at 85%-95% HRmax, interspersed with 3-min of recovery by running at 70% HRmax, 3 times per week for 6 weeks. All criterion measures were measured before and after training in both the groups. Results Due to attrition of four cases, data of 32 participants was used for analysis. A significant increase in high frequency (HF) power (p < 0.001) and decrease in the ratio of low frequency to high frequency power (LF/HF) ratio (p < 0.001) in HRV parameters, was observed post-HVHIIT, whereas, these variables did not change significantly (HF: p = 0.92, LF/HF ratio: p = 0.52) in LVHIIT group. Nevertheless, both the interventions proved equally effective in improving aerobic capacity (VO2max), body composition, and muscle strength. Conclusion The study results suggest that both LVHIIT and HVHIIT are equally effective in improving VO2max, body composition, and muscle strength, in sedentary young women. However, HVHIIT induces parasympathetic dominance as well, as measured by HRV.

  8. Measurement of hyolaryngeal muscle activation using surface electromyography for comparison of two rehabilitative dysphagia exercises.

    PubMed

    Watts, Christopher R

    2013-12-01

    To investigate the effects of a resistance-based chin-to-chest (CtC) exercise on measures of hyolaryngeal muscle activation compared with a head-lift exercise. Within-subject, repeated-measures design. Academic research laboratory. Healthy young women (N=20) without a history of dysphagia, cervical spine conditions, neurologic disease, or head/neck cancer (mean age, 22.5y). All participants performed an isometric jaw-opening exercise against resistance (CtC) and an isometric head-lift exercise, both targeting activation in the hyolaryngeal (suprahyoid) muscles. The CtC exercise required jaw opening into a chin brace secured against the upper torso for a duration of 10 seconds. The isometric head-lift exercise required lifting and holding the head from a supine position for 10 seconds. The degree to which each exercise activated the suprahyoid muscles was measured using surface electromyography (sEMG). Microvolts as measured from sEMG sensors placed on the skin surface above the hyolaryngeal muscles (surface of skin above geniohyoid, mylohyoid, and anterior digastric). Dependent variables included the peak microvolts during 10 seconds of sustained contraction and the difference in microvolts from rest to peak contraction for each exercise. Activation in the hyolaryngeal musculature as measured via sEMG was significantly greater when participants performed the CtC exercise compared with the head-lift exercise. Measures of peak microvolts during contraction were significantly greater for CtC (t=10.72, P<.001) compared with the head-lift exercise, and difference measures in microvolts calculated between rest and contraction for each exercise revealed a 2-fold increase in hyolaryngeal muscular activation for CtC (t=8.27, P<.001). The isometric CtC exercise resulted in greater activation of the hyolaryngeal muscles compared with an isometric head-lift exercise. Results support the need for further investigations to determine whether the CtC exercise has a positive effect

  9. Comparison of different heat modalities for treating delayed-onset muscle soreness in people with diabetes.

    PubMed

    Petrofsky, Jerrold; Batt, Jennifer; Bollinger, Jennifer N; Jensen, Mark C; Maru, Elyse H; Al-Nakhli, Hani H

    2011-06-01

    Delayed-onset muscle soreness (DOMS) is a serious problem for people who do not exercise on a regular basis. Although the best preventive measure for diabetes and for maintaining a low hemoglobin A1c is exercise, muscle soreness is common in people with diabetes. For people with diabetes, DOMS is rarely reported in exercise studies. One hundred twenty subjects participated in three groups (young, older, and type 2 diabetes) and were examined to evaluate the soreness in the abdominal muscles after a matched exercise bout using a p90x exercise video (Beachbody LLC, Los Angeles, CA) for core fitness. Next, three heating modalities were assessed on how well they could reduce muscle soreness: ThermaCare(®) (Pfizer Consumer Healthcare, Richmond, VA) heat wraps, hydrocollator heat wraps, and a chemical moist heat wrap. The results showed that people with diabetes were significantly sorer than age-matched controls (P < 0.05). On a 100-mm VAS (100 mm = sorest), the average soreness for the people with diabetes was 73.3 ± 16.2 mm, for the older group was 56.1 ± 15.1 mm, and for the younger group was 41.5 ± 9.3 mm; these differences were significant (analysis of variance, P < 0.05). The greatest reduction in soreness after applying the modalities was using moist heat, both immediately after the modality and up to 2 days after the exercise. Right after the modality, moist heat reduced pain by 52.3% in the older subjects compared with 30.5% in the subjects with diabetes and 33.3% in the younger subjects. Skin blood flow in the abdominal area before exercise was greatest in the younger subjects and lower in the subjects with diabetes after heat application. Skin temperature at rest and after exercise was greatest in the diabetes group. Muscle soreness following exercise was greatest in people with diabetes, and the best modality of the three studied to reduce this type of soreness was chemical moist heat.

  10. Comparison of different strongman events: trunk muscle activation and lumbar spine motion, load, and stiffness.

    PubMed

    McGill, Stuart M; McDermott, Art; Fenwick, Chad Mj

    2009-07-01

    Strongman events are attracting more interest as training exercises because of their unique demands. Further, strongman competitors sustain specific injuries, particularly to the back. Muscle electromyographic data from various torso and hip muscles, together with kinematic measures, were input to an anatomically detailed model of the torso to estimate back load, low-back stiffness, and hip torque. Events included the farmer's walk, super yoke, Atlas stone lift, suitcase carry, keg walk, tire flip, and log lift. The results document the unique demands of these whole-body events and, in particular, the demands on the back and torso. For example, the very large moments required at the hip for abduction when performing a yoke walk exceed the strength capability of the hip. Here, muscles such as quadratus lumborum made up for the strength deficit by generating frontal plane torque to support the torso/pelvis. In this way, the stiffened torso acts as a source of strength to allow joints with insufficient strength to be buttressed, resulting in successful performance. Timing of muscle activation patterns in events such as the Atlas stone lift demonstrated the need to integrate the hip extensors before the back extensors. Even so, because of the awkward shape of the stone, the protective neutral spine posture was impossible to achieve, resulting in substantial loading on the back that is placed in a weakened posture. Unexpectedly, the super yoke carry resulted in the highest loads on the spine. This was attributed to the weight of the yoke coupled with the massive torso muscle cocontraction, which produced torso stiffness to ensure spine stability together with buttressing the abduction strength insufficiency of the hips. Strongman events clearly challenge the strength of the body linkage, together with the stabilizing system, in a different way than traditional approaches. The carrying events challenged different abilities than the lifting events, suggesting that loaded

  11. Imaging of the muscle-bone relationship.

    PubMed

    Ireland, Alex; Ferretti, José Luis; Rittweger, Jörn

    2014-12-01

    Muscle can be assessed by imaging techniques according to its size (as thickness, area, volume, or alternatively, as a mass) and architecture (fiber length and pennation angle), with values used as an anthropometric measure or a surrogate for force production. Similarly, the size of the bone (as area or volume) can be imaged using MRI or pQCT, although typically bone mineral mass is reported. Bone imaging measures of mineral density, size, and geometry can also be combined to calculate bone's structural strength-measures being highly predictive of bone's failure load ex vivo. Imaging of muscle-bone relationships can, hence, be accomplished through a number of approaches by adoption and comparison of these different muscle and bone parameters, dependent on the research question under investigation. These approaches have revealed evidence of direct, mechanical muscle-bone interactions independent of allometric associations. They have led to important information on bone mechanoadaptation and the influence of muscular action on bone, in addition to influences of age, gender, exercise, and disuse on muscle-bone relationships. Such analyses have also produced promising diagnostic tools for clinical use, such as identification of primary, disuse-induced, and secondary osteoporosis and estimation of bone safety factors. Standardization of muscle-bone imaging methods is required to permit more reliable comparisons between studies and differing imaging modes, and in particular to aid adoption of these methods into widespread clinical practice.

  12. The head and neck muscles of the Philippine colugo (Dermoptera: Cynocephalus volans), with a comparison to tree-shrews, primates, and other mammals.

    PubMed

    Diogo, Rui

    2009-01-01

    The colugos, or flying lemurs (Dermoptera), are arboreal gliding mammals that are commonly grouped with tree-shrews (Scandentia) and Primates in the superorder Euarchonta. However, little is known about the head and neck muscles of these gliding mammals. This raises difficulties for the discussion of not only the functional morphology and evolution of colugos, but also the origin, evolution, functional morphology, and phylogenetic relationships of the Euarchonta as a whole, and thus also of our own clade, the Primates. In this work, I describe the head and neck muscles of the colugo Cynocephalus volans, and compare these muscles with those of other mammals, either dissected by me or described in the literature. My observations and comparisons indicate that, with respect to the number of muscles, the plesiomorphic condition for euarchontans as well as for primates is more similar to that found in extant tree-shrews than in extant colugos. This is because various muscles that were probably plesiomorphically present in the euarchontan and primate clades, as, e.g., the stylohyoideus, mandibulo-auricularis, cleido-occipitalis, omohyoideus, and sternohyoideus, are not present as independent elements in extant colugos. These observations and comparisons also indicate that various laryngeal and facial muscles that are present in modern humans were absent in the last common ancestor of extant primates.

  13. Reduction of total lung capacity in obese men: comparison of total intrathoracic and gas volumes

    PubMed Central

    Watson, R. A.; Thomas, E. Louise; Fitzpatrick, J.; Durighel, G.; McCarthy, J.; Morin, S. X.; Ind, P. W.; Bell, J. D.

    2010-01-01

    Restriction of total lung capacity (TLC) is found in some obese subjects, but the mechanism is unclear. Two hypotheses are as follows: 1) increased abdominal volume prevents full descent of the diaphragm; and 2) increased intrathoracic fat reduces space for full lung expansion. We have measured total intrathoracic volume at full inflation using magnetic resonance imaging (MRI) in 14 asymptomatic obese men [mean age 52 yr, body mass index (BMI) 35–45 kg/m2] and 7 control men (mean age 50 yr, BMI 22–27 kg/m2). MRI volumes were compared with gas volumes at TLC. All measurements were made with subjects supine. Obese men had smaller functional residual capacity (FRC) and FRC-to-TLC ratio than control men. There was a 12% predicted difference in mean TLC between obese (84% predicted) and control men (96% predicted). In contrast, differences in total intrathoracic volume (MRI) at full inflation were only 4% predicted TLC (obese 116% predicted TLC, control 120% predicted TLC), because mediastinal volume was larger in obese than in control [heart and major vessels (obese 1.10 liter, control 0.87 liter, P = 0.016) and intrathoracic fat (obese 0.68 liter, control 0.23 liter, P < 0.0001)]. As a consequence of increased mediastinal volume, intrathoracic volume at FRC in obese men was considerably larger than indicated by the gas volume at FRC. The difference in gas volume at TLC between the six obese men with restriction, TLC < 80% predicted (OR), and the eight obese men with TLC > 80% predicted (ON) was 26% predicted TLC. Mediastinal volume was similar in OR (1.84 liter) and ON (1.73 liter), but total intrathoracic volume was 19% predicted TLC smaller in OR than in ON. We conclude that the major factor restricting TLC in some obese men was reduced thoracic expansion at full inflation. PMID:20299612

  14. Final report on BIPM/CIPM key comparison CCM.FF-K4.2.2011: Volume comparison at 100 µL—Calibration of micropipettes (piston pipettes)

    NASA Astrophysics Data System (ADS)

    Batista, Elsa; Arias, Roberto; Jintao, Wang

    2013-01-01

    Five fixed micropipettes of 100 µl were tested by eight different National Metrology Institutes from different Regional Metrology Organizations between July 2011 and June 2012. The micropipettes had a stable volume, during the whole comparison, with a maximum standard deviation of 0.06 µl. After a careful analysis of the original results it was decided to make corrections to the standard atmospheric pressure in order to compare results under the same calibration conditions. These corrections led to a decrease of variability within the laboratories. It was also decided to include the stability of the standard and the method variability, determined by the pilot laboratory, in the uncertainty budget of each laboratory. The corrected results (volume and uncertainty) are consistent and overlap with the key comparison reference values for the micropipettes 354828Z, 354853Z and 354864Z. For the other two micropipettes only one result is not consistent with the reference value. Most results also overlap with those of the other laboratories di,j < U(di,j). An important outcome of this comparison is that in order to have comparable results, corrections for the working conditions must be applied to the laboratory results. Laboratories must always correct their reported volume results to a reference pressure condition and temperature (for example 101.325 kPa and 20 ºC) and this information should be stated in the calibration certificate of the micropipette. Also the standard uncertainty of the method variability and reproducibility values should always be included in the uncertainty budget (around 0.1%) to lead to more realistic uncertainty values. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement

  15. Evaluation of Gastric Volumes: Comparison of 3-D Ultrasound and Magnetic Resonance Imaging.

    PubMed

    Buisman, Wijnand J; Mauritz, Femke A; Westerhuis, Wouter E; Gilja, Odd Helge; van der Zee, David C; van Herwaarden-Lindeboom, Maud Y A

    2016-07-01

    To investigate gastric accommodation, accurate measurements of gastric volumes are necessary. An excellent technique to measure gastric volumes is dynamic magnetic resonance imaging (MRI). Unfortunately, dynamic MRI is expensive and not always available. A new 3-D ultrasound (US) method using a matrix transducer was developed to measure gastric volumes. In this prospective study, 14 healthy volunteers underwent a dynamic MRI and a 3-D US. Gastric volumes were calculated with intra-gastric liquid content and total gastric volume. Mean postprandial liquid gastric content was 397 ± 96.5 mL. Mean volume difference was 1.0 mL with limits of agreement of -8.9 to 10.9 mL. When gastric air was taken into account, mean total gastric volume was 540 ± 115.4 mL SD. Mean volume difference was 2.3 mL with limits of agreement of -21.1 to 26.4 mL. The matrix 3-D US showed excellent agreement with dynamic MRI. Therefore matrix 3-D US is a reliable alternative to measure gastric volumes.

  16. Hand volume estimates based on a geometric algorithm in comparison to water displacement.

    PubMed

    Mayrovitz, H N; Sims, N; Hill, C J; Hernandez, T; Greenshner, A; Diep, H

    2006-06-01

    Assessing changes in upper extremity limb volume during lymphedema therapy is important for determining treatment efficacy and documenting outcomes. Although arm volumes may be determined by tape measure, the suitability of circumference measurements to estimate hand volumes is questionable because of the deviation in circularity of hand shape. Our aim was to develop an alternative measurement procedure and algorithm for routine use to estimate hand volumes. A caliper was used to measure hand width and depth in 33 subjects (66 hands) and volumes (VE) were calculated using an elliptical frustum model. Using regression analysis and limits of agreement (LOA), VE was compared to volumes determined by water displacement (VW), to volumes calculated from tape-measure determined circumferences (VC), and to a trapezoidal model (VT). VW and VE (mean +/- SD) were similar (363 +/- 98 vs. 362 +/-100 ml) and highly correlated; VE = 1.01VW -3.1 ml, r=0.986, p<0.001, with LOA of +/- 33.5 ml and +/- 9.9 %. In contrast, VC (480 +/- 138 ml) and VT (432 +/- 122 ml) significantly overestimated volume (p<0.0001). These results indicate that the elliptical algorithm can be a useful alternative to water displacement when hand volumes are needed and the water displacement method is contra-indicated, impractical to implement, too time consuming or not available.

  17. Foot volume estimates based on a geometric algorithm in comparison to water displacement.

    PubMed

    Mayrovitz, H N; Sims, N; Litwin, B; Pfister, S

    2005-03-01

    Assessing lower extremity limb volume and its change during and after lymphedema therapy is important for determining treatment efficacy and documenting outcomes. Although leg volumes may be determined by tape measure and other methods, there is no metric method to routinely assess foot volumes. Exclusion of foot volumes can under- or overestimate therapeutic progress. Our aim was to develop and test a metric measurement procedure and algorithm for practicing therapists to use to estimate foot volumes. The method uses a caliper and ruler to measure foot dimensions at standardized locations and calculates foot volume (VM) by a mathematical algorithm. VM was compared to volumes measured by water displacement (Vw) in 30 subjects (60 feet) using regression analysis and limits of agreement (LOA). Vw and VM (mean +/- sd) were similar 857 +/- 150 ml vs. 859 +/- 154 ml, and were highly correlated VM = 1.00Vw + 1.67 ml, r = 0.965, p < 0.001. The LOA for absolute volume differences and percentages were respectively +/- 79.6 ml and +/- 9.28 %. These results indicate that this metric method can be a useful alternative to water displacement when foot volumes are needed, but the water displacement method is contraindicated, impractical to implement, too time consuming or is not available.

  18. Comparison of thoracic and abdominal cavity volumes during abdominal CO2 insufflation and abdominal wall lift.

    PubMed

    Watkins, Courtney; Fransson, Boel A; Ragle, Claude A; Mattoon, John; Gay, John M

    2013-06-01

    To compare thoracic and abdominal cavity volumes during abdominal CO2 insufflation and abdominal wall lift (AWL) conditions. In vitro cadaveric study. Mature medium-to-large breed fresh canine cadavers (n = 6). Each cadaver was imaged with computed tomography (CT) under baseline, abdominal CO2 insufflation, and AWL conditions. Measurements of thoracic and abdominal cavities were performed for each condition using image-analyzing software. Resulting volumes for each cadaver were converted to percent change from baseline to normalize the data. The t-tests were used to compare percent changes of both thoracic and abdominal volumes. Thoracic volume significantly decreased from baseline during CO2 insufflation (P < .01). No significant difference in thoracic volume occurred with AWL when compared with baseline. Abdominal volume increased by 80% with CO2 insufflation (95% CI: 56.4-107.0%) but only 25% with AWL (95% CI: 12.3-37.8%). Abdominal CO2 insufflation results in decreased thoracic volume when compared with baseline. AWL preserved thoracic volume similar to baseline. Abdominal volumes achieved with abdominal CO2 insufflation are significantly greater than those attained with AWL. © Copyright 2012 by The American College of Veterinary Surgeons.

  19. Calculating the tumor volume of acoustic neuromas: comparison of ABC/2 formula with planimetry method.

    PubMed

    Yu, Yi-Lin; Lee, Meei-Shyuan; Juan, Chun-Jung; Hueng, Dueng-Yuan

    2013-08-01

    The ABC/2 equation is commonly applied to measure the volume of intracranial hematoma. However, the precision of ABC/2 equation in estimating the tumor volume of acoustic neuromas is less addressed. The study is to evaluate the accuracy of the ABC/2 formula by comparing with planimetry method for estimating the tumor volumes. Thirty-two patients diagnosed with acoustic neuroma received contrast-enhanced magnetic resonance imaging of brain were recruited. The volume was calculated by the ABC/2 equation and planimetry method (defined as exact volume) at the same time. The 32 patients were divided into three groups by tumor volume to avoid volume-dependent overestimation (<3 ml, 3-6 ml and >6 ml). The tumor volume by ABC/2 method was highly correlated to that calculated by planimetry method using linear regression analysis (R2=0.985). Pearson correlation coefficient (r=0.993, p<0.001) demonstrates nearly perfect association between two methods. The ABC/2 formula is an easy method in estimating the tumor volume of acoustic neuromas that is not inferior to planimetry method. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Hindlimb muscle architecture in non-human great apes and a comparison of methods for analysing inter-species variation

    PubMed Central

    Myatt, Julia P; Crompton, Robin H; Thorpe, Susannah K S

    2011-01-01

    By relating an animal's morphology to its functional role and the behaviours performed, we can further develop our understanding of the selective factors and constraints acting on the adaptations of great apes. Comparison of muscle architecture between different ape species, however, is difficult because only small sample sizes are ever available. Further, such samples are often comprised of different age–sex classes, so studies have to rely on scaling techniques to remove body mass differences. However, the reliability of such scaling techniques has been questioned. As datasets increase in size, more reliable statistical analysis may eventually become possible. Here we employ geometric and allometric scaling techniques, and ancovas (a form of general linear model, GLM) to highlight and explore the different methods available for comparing functional morphology in the non-human great apes. Our results underline the importance of regressing data against a suitable body size variable to ascertain the relationship (geometric or allometric) and of choosing appropriate exponents by which to scale data. ancova models, while likely to be more robust than scaling for species comparisons when sample sizes are high, suffer from reduced power when sample sizes are low. Therefore, until sample sizes are radically increased it is preferable to include scaling analyses along with ancovas in data exploration. Overall, the results obtained from the different methods show little significant variation, whether in muscle belly mass, fascicle length or physiological cross-sectional area between the different species. This may reflect relatively close evolutionary relationships of the non-human great apes; a universal influence on morphology of generalised orthograde locomotor behaviours or, quite likely, both. PMID:21507000

  1. A comparison of inspiratory muscle fatigue following maximal exercise in moderately trained males and females.

    PubMed

    Ozkaplan, Atila; Rhodes, Edward C; Sheel, A William; Taunton, Jack E

    2005-09-01

    Exercise-induced inspiratory muscle fatigue (IMF) has been reported in males but there are few reports of IMF in females. It is not known if a gender difference exists for inspiratory muscle strength following heavy exercise, as is reported in locomotor muscles. Therefore, the relationship between fatigue and subsequent recovery of maximal inspiratory pressure (MIP) following exercise to maximal oxygen consumption (VO2max) was examined in a group of moderately trained males and females. Eighteen males (23+/-3 years; mean +/- SD) and 16 females (23+/-2 years) completed ten MIP and ten maximal handgrip (HG) strength maneuvers to establish baseline. Post-exercise MIP and HG were assessed successively immediately following a progressive intensity VO2max test on a cycle ergometer and at 1, 2, 3, 4, 5, 10, and 15 min. VO2max, relative to fat-free mass was not statistically different between males (62+/-7 ml kg(-1) min(-1)) and females (60+/-8 ml kg(-1) min(-1)). Males had higher absolute MIP values than females at all time intervals (P<0.05). Immediately following exercise, MIP was significantly reduced in both genders (M=83+/-16%; F=78+/-15% of baseline) but HG values were not different than resting values. MIP values remained depressed for both males and females throughout the 15 min (P<0.05). Differences for MIP between males and females were not statistically significant at any measurement time (P>0.05). The findings in this study conclude that IMF, observed immediately following maximal exercise, demonstrated the same pattern of recovery for both genders.

  2. Comparison of immunohistochemical and functional reinnervation of skin and muscle after peripheral nerve injury.

    PubMed

    Verdu, E; Navarro, X

    1997-07-01

    In order to investigate the usefulness of immunohistochemical detection of regenerating axons as a correlate of functional recovery, reinnervation of mouse foot pads, hairy skin, and muscle were studied at several intervals along 3 months after sciatic nerve crush using immunohistochemical markers PGP 9.5 and CGRP. These histological results were compared with functional recovery of sweat glands (SGs), plantar muscles, and pain sensibility. One week after nerve injury all neural functions were abolished in the operated hindpaw of all mice, no CGRP-immunoreactive (-ir) fibers were seen in the samples studied, while PGP 9.5 immunofluorescence remained at dim levels within nerve trunks, but disappeared from terminal innervation. The first PGP 9.5- and CGRP-ir regenerating fibers were seen at 15-16 days postoperation (dpo) in dermal nerve trunks of dorsal hairy skin and some days later in dermal trunks of foot pads. Regenerating nerve fibers progressed along the periphery of the dermis reinnervating the different dermal appendages. At 25 dpo all target organs were reinnervated. The first SGs activated by pilocarpine reappeared by 16 dpo and increased in number to 88% of control counts. Nociceptive responses reappeared at 17 dpo and reached 100% of control values. The first PGP immunofluorescence in neuromuscular junctions was seen at 16 dpo, while the first muscle action potentials were recorded at 19 dpo, and the potentials amplitude increased to 66% of controls. Good correlations were found between morphological and functional results of reinnervation. However, the density and distribution of nerve profiles in the tissues studied did not reach normal levels, while neural functions conveyed by small fibers reached levels similar to controls.

  3. Comparison of the effects of atenolol, sotalol and labetalol on muscle blood flow in man.

    PubMed Central

    Raman, G. V.; Mwongera, F. M.; Warren, D. J.

    1986-01-01

    A double-blind study of the effect of three beta-adrenoceptor blocking drugs (beta-blockers) on exercise muscle blood flow (MBF) in 14 normotensive volunteers was carried out. MBF was measured by the xenon-133 clearance technique. MBF was not altered by placebo, sotalol or labetalol. Atenolol significantly reduced MBF compared with placebo, sotalol and labetalol. We conclude that sotalol and labetalol may be more useful than conventional beta-blockers for treatment of hypertension or angina in association with peripheral vascular disease. PMID:2880341

  4. Comparison of Lower Extremity Kinematics and Hip Muscle Activation During Rehabilitation Tasks Between Sexes

    PubMed Central

    Dwyer, Maureen K.; Boudreau, Samantha N.; Mattacola, Carl G.; Uhl, Timothy L.; Lattermann, Christian

    2010-01-01

    Abstract Context: Closed kinetic chain exercises are an integral part of rehabilitation programs after lower extremity injury. Sex differences in lower extremity kinematics have been reported during landing and cutting; however, less is known about sex differences in movement patterns and activation of the hip musculature during common lower extremity rehabilitation exercises. Objective: To determine whether lower extremity kinematics and muscle activation levels differ between sexes during closed kinetic chain rehabilitation exercises. Design: Cross-sectional with 1 between-subjects factor (sex) and 1 within-subjects factor (exercise). Setting: Research laboratory. Patients or Other Participants: Participants included 21 women (age  =  23 ± 5.8 years, height  =  167.6 ± 5.1 cm, mass  =  63.7 ± 5.9 kg) and 21 men (age  =  23 ± 4.0 years, height  =  181.4 ± 7.4 cm, mass  =  85.6 ± 16.5 kg). Intervention(s): In 1 testing session, participants performed 3 trials each of single-leg squat, lunge, and step-up-and-over exercises. Main Outcome Measure(s): We recorded the peak joint angles (degrees) of knee flexion and valgus and hip flexion, extension, adduction, and external rotation for each exercise. We also recorded the electromyographic activity of the gluteus maximus, rectus femoris, adductor longus, and bilateral gluteus medius muscles for the concentric and eccentric phases of each exercise. Results: Peak knee flexion angles were smaller and peak hip extension angles were larger for women than for men across all tasks. Peak hip flexion angles during the single-leg squat were smaller for women than for men. Mean root-mean-square amplitudes for the gluteus maximus and rectus femoris muscles in both the concentric and eccentric phases of the 3 exercises were greater for women than for men. Conclusions: Sex differences were observed in sagittal-plane movement patterns during the rehabilitation exercises. Because of the sex differences

  5. Comparison of breast muscle traits and meat quality characteristics in 2 commercial chicken hybrids.

    PubMed

    Petracci, M; Sirri, F; Mazzoni, M; Meluzzi, A

    2013-09-01

    A trial was conducted to compare muscle traits and meat quality characteristics of the pectoralis muscle in 2 chicken commercial hybrids having standard (SBY) and high breast yield (HBY), respectively. A total of 2,124 one-day-old male chicks, equally divided into 2 experimental groups represented by strains (SBY and HBY), were grown using homogenous conditions and fed the same standard diets until reaching live weight of 4.2 kg at 53 and 55 d for the SBY and HBY groups, respectively. Thirty-six birds per each genotype were randomly selected, and their pectoralis major muscles were used to assess meat quality properties (color attributes, pH, drip loss, cook loss, Allo-Kramer shear values after cooking, moisture, proteins, total lipids, and ashes) as well as histological traits (cross-sectional area, frequency of abnormal fibers, and intramuscular fat infiltration). As expected, HBY genotype had higher breast yield (31.0 vs. 30.0%; P ≤ 0.05). Histological evaluations showed that HBY pectoralis muscles had higher cross-sectional fiber area coupled with a dramatically higher (P ≤ 0.001) incidence of abnormal fibers and more abundant infiltration of intramuscular fat. Moreover, histopathological anomalous features such as central nuclei, proliferation of endomysial and perimysial collagen, inflammatory infiltrate, and necrosis of the fibers were also observed. As for meat quality, SBY hybrid showed lower ultimate pH values (5.97 vs. 6.07; P ≤ 0.01), whereas overall color parameters were not affected by genotype. Breast meat from the HBY genotype also exhibited significantly lower ability to retain liquid during refrigerated storage (drip loss, 2.46 vs. 2.06%; P ≤ 0.05) and cooking (26.2 vs. 21.1%; P ≤ 0.05) as well as higher shear-force values (2.59 vs. 2.11 kg/g; P ≤ 0.001). Finally, with regard to chemical composition, significant differences (P ≤ 0.05) were detected in protein (22.8 vs. 23.5%) and lipid (1.65 vs. 1.82%) contents, which were

  6. Children and adults minimise activated muscle volume by selecting gait parameters that balance gross mechanical power and work demands.

    PubMed

    Hubel, Tatjana Y; Usherwood, James R

    2015-09-01

    Terrestrial locomotion on legs is energetically expensive. Compared with cycling, or with locomotion in swimming or flying animals, walking and running are highly uneconomical. Legged gaits that minimise mechanical work have previously been identified and broadly match walking and running at appropriate speeds. Furthermore, the 'cost of muscle force' approaches are effective in relating locomotion kinetics to metabolic cost. However, few accounts have been made for why animals deviate from either work-minimising or muscle-force-minimising strategies. Also, there is no current mechanistic account for the scaling of locomotion kinetics with animal size and speed. Here, we report measurements of ground reaction forces in walking children and adult humans, and their stance durations during running. We find that many aspects of gait kinetics and kinematics scale with speed and size in a manner that is consistent with minimising muscle activation required for the more demanding between mechanical work and power: spreading the duration of muscle action reduces activation requirements for power, at the cost of greater work demands. Mechanical work is relatively more demanding for larger bipeds--adult humans--accounting for their symmetrical M-shaped vertical force traces in walking, and relatively brief stance durations in running compared with smaller bipeds--children. The gaits of small children, and the greater deviation of their mechanics from work-minimising strategies, may be understood as appropriate for their scale, not merely as immature, incompletely developed and energetically sub-optimal versions of adult gaits. © 2015. Published by The Company of Biologists Ltd.

  7. Specificity of abnormal brain volume in major depressive disorder: a comparison with borderline personality disorder.

    PubMed

    Depping, Malte S; Wolf, Nadine D; Vasic, Nenad; Sambataro, Fabio; Thomann, Philipp A; Christian Wolf, R

    2015-03-15

    Abnormal brain volume has been frequently demonstrated in major depressive disorder (MDD). It is unclear if these findings are specific for MDD since aberrant brain structure is also present in disorders with depressive comorbidity and affective dysregulation, such as borderline personality disorder (BPD). In this transdiagnostic study, we aimed to investigate if regional brain volume loss differentiates between MDD and BPD. Further, we tested for associations between brain volume and clinical variables within and between diagnostic groups. 22 Females with a DSM-IV diagnosis of MDD, 17 females with a DSM-IV diagnosis of BPD and without comorbid posttraumatic stress disorder, and 22 age-matched female healthy controls (HC) were investigated using magnetic resonance imaging. High-resolution structural data were analyzed using voxel-based morphometry. A significant (p<0.05, cluster-corrected) volume decrease of the anterior cingulate cortex (ACC) was found in MDD compared to HC, as opposed to volume decreases of the amygdala in BPD compared to both HC and MDD. Sensitivity and specificity of regional gray matter volume for a diagnosis of MDD were modest to fair. Amygdala volume was related to depressive symptoms across the entire patient sample. Potential limitations of this study include the modest sample size and the heterogeneous psychotropic drug treatment. ACC volume reduction is more pronounced in MDD with an intermediate degree of volume loss in BPD compared to HC. In contrast, amygdala volume loss is more pronounced in BPD compared to MDD, yet amygdala volume is associated with affective symptom expression in both disorders. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. A comparison of low volume 'high-intensity-training' and high volume traditional resistance training methods on muscular performance, body composition, and subjective assessments of training

    PubMed Central

    Giessing, J; Eichmann, B; Fisher, J

    2016-01-01

    Most studies of resistance training (RT) examine methods that do not resemble typical training practices of persons participating in RT. Ecologically valid RT programs more representative of such practices are seldom compared. This study compared two such approaches to RT. Thirty participants (males, n = 13; females, n = 17) were randomised to either a group performing low volume 'High Intensity Training' (HIT; n = 16) or high volume 'Body-building' (3ST; n = 14) RT methods 2x/week for 10 weeks. Outcomes included muscular performance, body composition, and participant's subjective assessments. Both HIT and 3ST groups improved muscular performance significantly (as indicated by 95% confidence intervals) with large effect sizes (ES; 0.97 to 1.73 and 0.88 to 1.77 respectively). HIT had significantly greater muscular performance gains for 3 of 9 tested exercises compared with 3ST (p < 0.05) and larger effect sizes for 8 of 9 exercises. Body composition did not significantly change in either group. However, effect sizes for whole body muscle mass changes were slightly more favourable in the HIT group compared with the 3ST group (0.27 and -0.34 respectively) in addition to whole body fat mass (0.03 and 0.43 respectively) and whole body fat percentage (-0.10 and -0.44 respectively). Significant muscular performance gains can be produced using either HIT or 3ST. However, muscular performance gains may be greater when using HIT. Future research should look to identify which components of ecologically valid RT programs are primarily responsible for these differences in outcome. PMID:27601778

  9. Dosimetric Comparison of Split Field and Fixed Jaw Techniques for Large IMRT Target Volumes in the Head and Neck

    SciTech Connect

    Srivastava, Shiv P.; Das, Indra J.; Kumar, Arvind; Johnstone, Peter A.S.

    2011-04-01

    Some treatment planning systems (TPSs), when used for large-field (>14 cm) intensity-modulated radiation therapy (IMRT), create split fields that produce excessive multiple-leaf collimator segments, match-line dose inhomogeneity, and higher treatment times than nonsplit fields. A new method using a fixed-jaw technique (FJT) forces the jaw to stay at a fixed position during optimization and is proposed to reduce problems associated with split fields. Dosimetric comparisons between split-field technique (SFT) and FJT used for IMRT treatment is presented. Five patients with head and neck malignancies and regional target volumes were studied and compared with both techniques. Treatment planning was performed on an Eclipse TPS using beam data generated for Varian 2100C linear accelerator. A standard beam arrangement consisting of nine coplanar fields, equally spaced, was used in both techniques. Institutional dose-volume constraints used in head and neck cancer were kept the same for both techniques. The dosimetric coverage for the target volumes between SFT and FJT for head and neck IMRT plan is identical within {+-}1% up to 90% dose. Similarly, the organs at risk (OARs) have dose-volume coverage nearly identical for all patients. When the total monitor unit (MU) and segments were analyzed, SFT produces statistically significant higher segments (17.3 {+-} 6.3%) and higher MU (13.7 {+-} 4.4%) than the FJT. There is no match line in FJT and hence dose uniformity in the target volume is superior to the SFT. Dosimetrically, SFT and FJT are similar for dose-volume coverage; however, the FJT method provides better logistics, lower MU, shorter treatment time, and better dose uniformity. The number of segments and MU also has been correlated with the whole body radiation dose with long-term complications. Thus, FJT should be the preferred option over SFT for large target volumes.

  10. Dosimetric comparison of split field and fixed jaw techniques for large IMRT target volumes in the head and neck.

    PubMed

    Srivastava, Shiv P; Das, Indra J; Kumar, Arvind; Johnstone, Peter A S

    2011-01-01

    Some treatment planning systems (TPSs), when used for large-field (>14 cm) intensity-modulated radiation therapy (IMRT), create split fields that produce excessive multiple-leaf collimator segments, match-line dose inhomogeneity, and higher treatment times than nonsplit fields. A new method using a fixed-jaw technique (FJT) forces the jaw to stay at a fixed position during optimization and is proposed to reduce problems associated with split fields. Dosimetric comparisons between split-field technique (SFT) and FJT used for IMRT treatment is presented. Five patients with head and neck malignancies and regional target volumes were studied and compared with both techniques. Treatment planning was performed on an Eclipse TPS using beam data generated for Varian 2100C linear accelerator. A standard beam arrangement consisting of nine coplanar fields, equally spaced, was used in both techniques. Institutional dose-volume constraints used in head and neck cancer were kept the same for both techniques. The dosimetric coverage for the target volumes between SFT and FJT for head and neck IMRT plan is identical within ± 1% up to 90% dose. Similarly, the organs at risk (OARs) have dose-volume coverage nearly identical for all patients. When the total monitor unit (MU) and segments were analyzed, SFT produces statistically significant higher segments (17.3 ± 6.3%) and higher MU (13.7 ± 4.4%) than the FJT. There is no match line in FJT and hence dose uniformity in the target volume is superior to the SFT. Dosimetrically, SFT and FJT are similar for dose-volume coverage; however, the FJT method provides better logistics, lower MU, shorter treatment time, and better dose uniformity. The number of segments and MU also has been correlated with the whole body radiation dose with long-term complications. Thus, FJT should be the preferred option over SFT for large target volumes. Copyright © 2011 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights

  11. Comparison of knee laxity and isokinetic muscle strength in patients with a posterior cruciate ligament injury

    PubMed Central

    Jeon, Kyoungkyu

    2016-01-01

    [Purpose] The aim of this study was to compare knee laxity and isokinetic muscle strength in patients with an isolated posterior cruciate ligament injury. [Subjects and Methods] Twenty high school rugby players with a previous posterior cruciate ligament injury and abnormal findings higher than surgical grade I were included. Laxity with 132 N of pressure was measured using Kneelax 3 to assess the stability of the posterior cruciate ligament, and flexor and extensor torques were measured at 60°/sec, 180°/sec, and 240°/sec to measure the isokinetic muscle strength of the knee joint. The average and standard deviation values were extracted from all data to assess the measured data. [Results] Regarding the ipsilateral and contralateral laxity, the deviation value at the peak force and maximum manual drawer was statistically significant. The peak torque and peak torque per body weight in isokinetic measurements were significantly different only for knee extensor torque at 60°/sec, 180°/sec, and 240°/sec. [Conclusion] Return to normal activities post injury is important. Thus base data gathered by comparing patients’ ipsilateral and contralateral sides will serve as essential criteria for structuring future rehabilitation programs to facilitate functional improvements. PMID:27134367

  12. Intraexaminer comparison of applied kinesiology manual muscle testing of varying durations: a pilot study

    PubMed Central

    Conable, Katharine M.

    2010-01-01

    Objective The purpose of this study is to investigate the difference in results (strong/facilitated vs weak/functionally inhibited) between short (1 second) and long (3 seconds) manual muscle tests (MMTs) on the same subject and to pilot the use of thin-film force transducers for characterizing the parameters of MMT and for measuring maximum voluntary isometric contraction (MVIC). Method Forty-four healthy chiropractic students were tested. A thin-film force transducer recorded force over time during MVIC of the middle deltoid and 1- and 3-second MMTs of the same subjects. The MMTs were graded as strong (able to resist the testing pressure) or weak (unable to resist testing pressure, breaking away). Results Forty-two short tests were strong, and 2 were weak. Thirty-nine long tests were strong, and 5 were weak. κ (0.54) showed fair agreement for results between short and long tests. Peak force in both short and long weak tests was higher than that in strong tests when expressed as a proportion of maximum contraction. All manual tests used less force than MVICs. Conclusions This study demonstrated that a study of this nature is feasible. Longer test durations demonstrate some muscle weaknesses that are not evident on 1-second MMTs. Thin-film transducers show promise for recording MMT parameters for research purposes. PMID:21572637

  13. Comparison of knee laxity and isokinetic muscle strength in patients with a posterior cruciate ligament injury.

    PubMed

    Jeon, Kyoungkyu

    2016-03-01

    [Purpose] The aim of this study was to compare knee laxity and isokinetic muscle strength in patients with an isolated posterior cruciate ligament injury. [Subjects and Methods] Twenty high school rugby players with a previous posterior cruciate ligament injury and abnormal findings higher than surgical grade I were included. Laxity with 132 N of pressure was measured using Kneelax 3 to assess the stability of the posterior cruciate ligament, and flexor and extensor torques were measured at 60°/sec, 180°/sec, and 240°/sec to measure the isokinetic muscle strength of the knee joint. The average and standard deviation values were extracted from all data to assess the measured data. [Results] Regarding the ipsilateral and contralateral laxity, the deviation value at the peak force and maximum manual drawer was statistically significant. The peak torque and peak torque per body weight in isokinetic measurements were significantly different only for knee extensor torque at 60°/sec, 180°/sec, and 240°/sec. [Conclusion] Return to normal activities post injury is important. Thus base data gathered by comparing patients' ipsilateral and contralateral sides will serve as essential criteria for structuring future rehabilitation programs to facilitate functional improvements.

  14. Neck muscle endurance and head posture: A comparison between adolescents with and without neck pain.

    PubMed

    Oliveira, Ana Carolina; Silva, Anabela G

    2016-04-01

    The main aims of this study were to compare the neck flexor and extensor endurance and forward head posture between adolescents with and without neck pain. The secondary aims were to explore potential associations between muscles endurance, head posture and neck pain characteristics and to assess intra-rater reliability of the measurements used. Adolescents with neck pain (n = 35) and age-matched asymptomatic adolescents (n = 35) had their forward head posture, neck flexor endurance and neck extensor endurance measured using clinical tests. Intra-rater reliability was also assessed. Forward head posture and neck flexor and extensor endurance tests showed moderate to almost perfect intra-rater reliability (ICC between 0.58 and 0.88). Adolescents with neck pain showed significantly less forward head posture (neck pain = 46.62 ± 4.92; asymptomatic = 44.18°± 3.64°, p > 0.05) and less neck flexor (neck pain = 24.50 ± 23.03s; asymptomatic = 35.89 ± 21.53s, p > 0.05) and extensor endurance (neck pain = 12.6.64 ± 77.94s; asymptomatic = 168.66 ± 74.77s, p > 0.05) than asymptomatic adolescents. Results suggest that changes in posture and neck muscle endurance are a feature of adolescents with neck pain. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Men, muscles, and body image: comparisons of competitive bodybuilders, weight trainers, and athletically active controls

    PubMed Central

    Pickett, T; Lewis, R; Cash, T; Pope, H

    2005-01-01

    Objectives: To investigate body image and psychosocial adjustment among competitive bodybuilders, non-competitive weight trainers, and athletically active men. Methods: Participants were 40 men in each of the three groups who were assessed on body composition and multiple facets of body image evaluation, investment and anxiety, eating attitudes, and social self esteem. Results: Relative to the other two groups, competitive bodybuilders had greater body mass due to fat-free body mass. Although groups did not differ in their situational body image discomfort, competitive bodybuilders and weight trainers had a more positive global appearance evaluation and were more psychologically invested in their physical appearance. Compared with active controls, men in both weightlifting groups were more satisfied with their upper torso and muscle tone. Competitive bodybuilders reported more mid torso satisfaction than the other two groups. Competitive bodybuilders also wished to be significantly heavier than controls did and reported higher social self esteem but greater eating disturbance. Conclusions: The findings suggest that competitive bodybuilders as a group are not more "muscle dysmorphic" than either non-competitive weight trainers or physically active men who do not train with weights. PMID:15793091

  16. Comparison of tissue effects in rabbit muscle of surgical dissection devices.

    PubMed

    Bowers, Christian A; Burns, Greg; Salzman, Karen L; McGill, Lawrence D; Macdonald, Joel D

    2014-01-01

    While some energy-based surgical dissection and coagulation modalities may offer excellent cutting and coagulation abilities, the impact on healing may differ among devices. We compared the tissue effects of three of these modalities with those of the standard surgical scalpel in rabbit muscle at 24 h and 14 days after surgery by evaluating radiographic and histological data. Linear incisions were made with each device in the dorsal lumbar musculature of rabbits using monopolar electrocautery in cut mode (MPE-Cut) and coagulation mode (MPE-Coag), a ferromagnetic induction loop (FMI), and a traditional scalpel. Magnetic resonance imaging scans and histological sampling were done at 24 h and 14 days. Subjective cutting and coagulation characteristics for each device were also recorded during surgery. The scalpel and FMI appeared to cause the least tissue damage adjacent to the incisions in rabbit dorsal lumbar musculature. The scalpel showed the best healing, while the FMI and MPE-Cut demonstrated good healing. The MPE-Coag showed the worst tissue healing. The scalpel, FMI, and MPE-Cut all exhibited favorable subjective characteristics during surgery. It appears that the FMI may be a better choice for surgical dissection and coagulation in muscle tissue than the MPE coagulation mode because it shows less tissue damage and offers better tissue healing. Copyright © 2014 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  17. Comparison of endoscopic surgery and open surgery for gluteal muscle contracture.

    PubMed

    Fu, Dehao; Yang, Shuhua; Xiao, Baojun; Wang, Hong; Meng, Chunqing

    2011-01-01

    To compare the clinical effects of endoscopic surgeries with traditional open surgeries in the treatment of gluteal muscle contracture and discuss their indications and value. In this retrospective study, 50 patients received traditional open surgeries and 52 received endoscopic surgeries. The 2 groups were compared in terms of surgery duration, incision lengths, postsurgical pain, complications, off-bed activity times, hospitalization duration, clinical outcome, and 1-year recurrence rates. The endoscopic surgery group was significantly superior to the open surgery group in regard to incision length, postsurgical pain, off-bed activity time, hospitalization duration, and patient cosmetic satisfaction. Differences were not statistically significant for the surgery duration, complications, clinical outcome, or the 1-year recurrence rate. All the endoscopic surgery group patients stated that they would choose endoscopic surgery again. The endoscopic release of gluteal muscle contracture is safe and reliable, with the advantages of less trauma and pain, shorter operative time, earlier rehabilitation, and return of functional activities. Its application, though, should be carefully controlled based on the indications. It is applicable to degree I and II patients, but may be used only very cautiously in degree III patients. Level III.

  18. Peptides PHI and VIP: comparison between vascular and nonvascular smooth muscle effect in rabbit uterus

    SciTech Connect

    Bardrum, B.; Ottesen, B.; Fahrenkrug, J.

    1986-07-01

    The distribution and effects of the two neuropeptides, vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine amide (PHI), on vascular and nonvascular smooth muscle in the urogenital tract of nonpregnant rabbit female, were investigated. Immunoreactive VIP and PHI were present in all regions except the ovary with the highest concentration in the uterin cervix. By using in vitro tension recordings of myometrial specimens, it was demonstrated that both peptides displayed a dose-dependent inhibition of the mechanical activity. The dose-response curves of VIP and PHI were superimposable with and ID50 of 3 x 10 Y mol/l, and their combined effect was additive. In addition, the influence of the two peptides on myometrial blood flow (MBF) was investigated by the xenon-133 washout technique. Both peptides were found to increase MBF with the same potency and efficacy. Their combined effect was additive. In conclusion VIP and PHI are present in the rabbit urogenital tract, and the two peptides are equipotent inhibitors of mechanical nonvascular and vascular smooth muscle activity in the uterus.

  19. A Comparison of Regional and SiteSpecific Volume Estimation Equations

    Treesearch

    Joe P. McClure; Jana Anderson; Hans T. Schreuder

    1987-01-01

    Regression equations for volume by region and site class were examined for lobiolly pine. The regressions for the Coastal Plain and Piedmont regions had significantly different slopes. The results shared important practical differences in percentage of confidence intervals containing the true total volume and in percentage of estimates within a specific proportion of...

  20. Comparison of Past, Present, and Future Volume Estimation Methods for Tennessee

    Treesearch

    Stanley J. Zarnoch; Alexander Clark; Ray A. Souter

    2003-01-01

    Forest Inventory and Analysis 1999 survey data for Tennessee were used to compare stem-volume estimates obtained using a previous method, the current method, and newly developed taper models that will be used in the future. Compared to the current method, individual tree volumes were consistently underestimated with the previous method, especially for the hardwoods....

  1. Glacier volume estimation of Cascade Volcanoes—an analysis and comparison with other methods

    USGS Publications Warehouse

    Driedger, Carolyn L.; Kennard, P.M.

    1986-01-01

    During the 1980 eruption of Mount St. Helens, the occurrence of floods and mudflows made apparent a need to assess mudflow hazards on other Cascade volcanoes. A basic requirement for such analysis is information about the volume and distribution of snow and ice on these volcanoes. An analysis was made of the volume-estimation methods developed by previous authors and a volume estimation method was developed for use in the Cascade Range. A radio echo-sounder, carried in a backpack, was used to make point measurements of ice thickness on major glaciers of four Cascade volcanoes (Mount Rainier, Washington; Mount Hood and the Three Sisters, Oregon; and Mount Shasta, California). These data were used to generate ice-thickness maps and bedrock topographic maps for developing and testing volume-estimation methods. Subsequently, the methods were applied to the unmeasured glaciers on those mountains and, as a test of the geographical extent of applicability, to glaciers beyond the Cascades having measured volumes. Two empirical relationships were required in order to predict volumes for all the glaciers. Generally, for glaciers less than 2.6 km in length, volume was found to be estimated best by using glacier area, raised to a power. For longer glaciers, volume was found to be estimated best by using a power law relationship, including slope and shear stress. The necessary variables can be estimated from topographic maps and aerial photographs.

  2. Comparison of Node-Centered and Cell-Centered Unstructured Finite-Volume Discretizations: Viscous Fluxes

    NASA Technical Reports Server (NTRS)

    Diskin, Boris; Thomas, James L.; Nielsen, Eric J.; Nishikawa, Hiroaki; White, Jeffery A.

    2010-01-01

    Discretization of the viscous terms in current finite-volume unstructured-grid schemes are compared using node-centered and cell-centered approaches in two dimensions. Accuracy and complexity are studied for four nominally second-order accurate schemes: a node-centered scheme and three cell-centered schemes - a node-averaging scheme and two schemes with nearest-neighbor and adaptive compact stencils for least-square face gradient reconstruction. The grids considered range from structured (regular) grids to irregular grids composed of arbitrary mixtures of triangles and quadrilaterals, including random perturbations of the grid points to bring out the worst possible behavior of the solution. Two classes of tests are considered. The first class of tests involves smooth manufactured solutions on both isotropic and highly anisotropic grids with discontinuous metrics, typical of those encountered in grid adaptation. The second class concerns solutions and grids varying strongly anisotropically over a curved body, typical of those encountered in high-Reynolds number turbulent flow simulations. Tests from the first class indicate the face least-square methods, the node-averaging method without clipping, and the node-centered method demonstrate second-order convergence of discretization errors with very similar accuracies per degree of freedom. The tests of the second class are more discriminating. The node-centered scheme is always second order with an accuracy and complexity in linearization comparable to the best of the cell-centered schemes. In comparison, the cell-centered node-averaging schemes may degenerate on mixed grids, have a higher complexity in linearization, and can fail to converge to the exact solution when clipping of the node-averaged values is used. The cell-centered schemes using least-square face gradient reconstruction have more compact stencils with a complexity similar to that of the node-centered scheme. For simulations on highly anisotropic

  3. Plasma volume by Evans blue: effects of eating and comparison with other methods at altitude.

    PubMed

    Loeppky, Jack A; Luther, Deborah K; Maes, Damon; Riboni, Katrina; Hinghofer-Szalkay, Helmut; Charlton, Gerald A; Icenogle, Milton V

    2002-09-01

    Measurements of plasma volume (PV) and its changes (delta%PV) by Evans blue (EB) dye are presumed to be valid only in fasting subjects. In addition, delta%PVEB with acute altitude exposure has not been compared with other methods employing the concentration or dilution of naturally occurring blood (hematocrit (Hct), hemoglobin (Hb)) and plasma (density, proteins) components, but should be similar if capillary permeability and the sampled vein/whole body Hct ratio remain unchanged. PVEB was determined in six subjects while fasting or eating on different days, with injection and sampling in the same arm, 4-h extrapolation to time zero and correcting readings with the 620-740 A method. For 93 experiments at altitude, delta%PVEB was obtained similarly from a 3-h extrapolation near the end of a 12-h chamber exposure to 426 mm Hg (-4,880 m =16,000 ft) and at the same time on the preceding control day. Mean PVEB with and without eating was not significantly different (SE of absolute difference = +/- 2.8%). The EB decay curves had significantly more scatter with eating than fasting. The fasting vs. non-fasting values for the single 20-min post-injection point also gave a close comparison (r = +0.97). At altitude the loss in PV measured with EB was significantly greater (delta%PVEB = -6.3%) than losses estimated from Hct-Hb (-2.9%), plasma protein (-3.7%), and plasma density (-3.9%). The expected larger PV loss in subjects tolerant to altitude sickness compared with intolerant ones was most clearly shown by delta%PVEB (8.8%). Obtaining more samples can offset reproducibility lost by eating. The delta%PVEB were largest and nearest to values previously reported at altitude, perhaps because the single baseline and altitude samples utilized by the other methods are more sensitive to subtle, transient fluctuations in body water and vasomotor tone associated with apprehension, vomiting, fluid intake, and regional vasodilation and constriction.

  4. Human-computer interaction in radiotherapy target volume delineation: a prospective, multi-institutional comparison of user input devices.

    PubMed

    2011-10-01

    The purpose of this study was the prospective comparison of objective and subjective effects of target volume region of interest (ROI) delineation using mouse-keyboard and pen-tablet user input devices (UIDs). The study was designed as a prospective test/retest sequence, with Wilcoxon signed rank test for matched-pair comparison. Twenty-one physician-observers contoured target volume ROIs on four standardized cases (representative of brain, prostate, lung, and head and neck malignancies) twice: once using QWERTY keyboard/scroll-wheel mouse UID and once with pen-tablet UID (DTX2100, Wacom Technology Corporation, Vancouver, WA, USA). Active task time, ROI manipulation task data, and subjective survey data were collected. One hundred twenty-nine target volume ROI sets were collected, with 62 paired pen-tablet/mouse-keyboard sessions. Active contouring time was reduced using the pen-tablet UID, with mean ± SD active contouring time of 26 ± 23 min, compared with 32 ± 25 with the mouse (p ≤ 0.01). Subjective estimation of time spent was also reduced from 31 ± 26 with mouse to 27 ± 22 min with the pen (p = 0.02). Task analysis showed ROI correction task reduction (p = 0.045) and decreased panning and scrolling tasks (p < 0.01) with the pen-tablet; drawing, window/level changes, and zoom commands were unchanged (p = n.s.) Volumetric analysis demonstrated no detectable differences in ROI volume nor intra- or inter-observer volumetric coverage. Fifty-two of 62 (84%) users preferred the tablet for each contouring task; 5 of 62 (8%) denoted no preference, and 5 of 62 (8%) chose the mouse interface. The pen-tablet UID reduced active contouring time and reduced correction of ROIs, without substantially altering ROI volume/coverage.

  5. Comparison of Tidal Volumes at the Endotracheal Tube and at the Ventilator.

    PubMed

    Kim, Paul; Salazar, Adler; Ross, Patrick A; Newth, Christopher J L; Khemani, Robinder G

    2015-11-01

    Lung protective ventilation for children with acute respiratory distress syndrome requires accurate assessment of tidal volume. Although modern ventilators compensate for ventilator tubing compliance, tidal volume measured at the ventilator may not be accurate, particularly in small children. Although ventilator-specific proximal flow sensors that measure tidal volume at the endotracheal tube have been developed, there is little information regarding their accuracy. We sought to test the accuracy of ventilator measured tidal volume with and without proximal flow sensors against a calibrated pneumotachometer in children. Prospective, observational. Tertiary care PICU. Fifty-one endotracheally intubated and mechanically ventilated children younger than 18 years. Tidal volumes were measured at the ventilator, using a ventilator-specific flow sensor, and a calibrated pneumotachometer connected to the SensorMedics 2600A Pediatric Pulmonary Function Cart. In a pressure control mode of ventilation: median tidal volume measured with the pneumotachometer (9.5 mL/kg [interquartile range, 8.2-11.7 mL/kg]) was significantly higher than tidal volume measured either at the ventilator (8.2 mL/kg [7.1-9.6 mL/kg]) or at the proximal flow sensor (8.1 mL/kg [7.2-10.0 mL/kg]) (p < 0.001). In pressure regulated volume control mode of ventilation: median tidal volume measured with the pneumotachometer (10.2 mL/kg [8.8-12.4 mL/kg]) was significantly higher than tidal volume measured either at the ventilator (8.0 mL/kg [7.1-9.7 mL/kg]) or at the proximal flow sensor (8.5 mL/kg [7.3-10.4 mL/kg]) (p < 0.001). These findings were consistent when subgrouped by ventilator type and circuit size. Tidal volume measured either at the endotracheal tube with a proximal flow sensor or at the ventilator with compensation for tubing compliance are both significantly lower than tidal volume measured with a calibrated pneumotachometer. This underestimation of delivered tidal volume may be particularly

  6. What is the best reference site for a single MRI slice to assess whole-body skeletal muscle and adipose tissue volumes in healthy adults?

    PubMed

    Schweitzer, Lisa; Geisler, Corinna; Pourhassan, Maryam; Braun, Wiebke; Glüer, Claus-Christian; Bosy-Westphal, Anja; Müller, Manfred J

    2015-07-01

    Whole-body magnetic resonance imaging (MRI) is the gold standard for the assessment of skeletal muscle (SM) and adipose tissue volumes. It is unclear whether single-slice estimates can replace whole-body data. We evaluated the accuracy of the best single lumbar and midthigh MRI slice to assess whole-body SM, visceral adipose tissue (VAT), and subcutaneous adipose tissue (SAT). Whole-body MRI was performed in 142 healthy adults aged 19-65 y [mean ± SD age: 37.0 ± 11.8 y; BMI (in kg/m(2)): 25.3 ± 5.9]. Single slices were taken at lumbar vertebrae L1-L5 plus intervertebral discs and the thigh (midthigh, 10 cm distally from the midthigh, and 10 cm proximally from the midthigh). The value of single-slice areas was also tested in a longitudinal study on 48 healthy volunteers during weight loss (8.2 ± 5.2 kg). Cross-sectionally, all SM and adipose tissue single-slice areas correlated with total tissue volumes (P < 0.01). Because of the close associations between L3 areas and corresponding tissue volumes (r = 0.832-0.986, P < 0.01), this location was identified as the reference to estimate SM and adipose tissue in both sexes. SM, SAT, and VAT areas at L3 explained most of the variance of total tissue volumes (69-97%, with SEs of estimation of 1.96 and 2.03 L for SM, 0.23 and 0.61 L for VAT, and 4.44 and 2.47 L for SAT for men and women, respectively. There was no major effect on the explained variance compared with that for optimal slices. For SM, the optimal slice area was shown at midthigh. With weight-loss changes in total SM, VAT, and SAT, volumes were significantly different from those at baseline (SM changes: -2.8 ± 2.9 L; VAT changes: -0.7 ± 1.0 L; SAT changes: -5.1 ± 6.0 L). The area at L3 reflected changes in total VAT and SAT. To assess changes in total SM volumes, areas at midthigh showed the best evidence. In both sexes, a single MRI scan at the level of L3 is the best compromise site to assess total tissue volumes of SM, VAT, and SAT. By contrast, L3

  7. Comparison of three methods for the estimation of pineal gland volume using magnetic resonance imaging.

    PubMed

    Acer, Niyazi; Ilıca, Ahmet Turan; Turgut, Ahmet Tuncay; Ozçelik, Ozlem; Yıldırım, Birdal; Turgut, Mehmet

    2012-01-01

    Pineal gland is a very important neuroendocrine organ with many physiological functions such as regulating circadian rhythm. Radiologically, the pineal gland volume is clinically important because it is usually difficult to distinguish small pineal tumors via magnetic resonance imaging (MRI). Although many studies have estimated the pineal gland volume using different techniques, to the best of our knowledge, there has so far been no stereological work done on this subject. The objective of the current paper was to determine the pineal gland volume using stereological methods and by the region of interest (ROI) on MRI. In this paper, the pineal gland volumes were calculated in a total of 62 subjects (36 females, 26 males) who were free of any pineal lesions or tumors. The mean ± SD pineal gland volumes of the point-counting, planimetry, and ROI groups were 99.55 ± 51.34, 102.69 ± 40.39, and 104.33 ± 40.45 mm(3), respectively. No significant difference was found among the methods of calculating pineal gland volume (P > 0.05). From these results, it can be concluded that each technique is an unbiased, efficient, and reliable method, ideally suitable for in vivo examination of MRI data for pineal gland volume estimation.

  8. Comparison of Three Methods for the Estimation of Pineal Gland Volume Using Magnetic Resonance Imaging

    PubMed Central

    Acer, Niyazi; Ilıca, Ahmet Turan; Turgut, Ahmet Tuncay; Özçelik, Özlem; Yıldırım, Birdal; Turgut, Mehmet

    2012-01-01

    Pineal gland is a very important neuroendocrine organ with many physiological functions such as regulating circadian rhythm. Radiologically, the pineal gland volume is clinically important because it is usually difficult to distinguish small pineal tumors via magnetic resonance imaging (MRI). Although many studies have estimated the pineal gland volume using different techniques, to the best of our knowledge, there has so far been no stereological work done on this subject. The objective of the current paper was to determine the pineal gland volume using stereological methods and by the region of interest (ROI) on MRI. In this paper, the pineal gland volumes were calculated in a total of 62 subjects (36 females, 26 males) who were free of any pineal lesions or tumors. The mean ± SD pineal gland volumes of the point-counting, planimetry, and ROI groups were 99.55 ± 51.34, 102.69 ± 40.39, and 104.33 ± 40.45 mm3, respectively. No significant difference was found among the methods of calculating pineal gland volume (P > 0.05). From these results, it can be concluded that each technique is an unbiased, efficient, and reliable method, ideally suitable for in vivo examination of MRI data for pineal gland volume estimation. PMID:22619577

  9. [Volume of the irradiated small intestine during pelvic radiotherapy. Comparison of various calculation methods].

    PubMed

    Bonetta, A; Capirci, C; Lambertini, D; Zingoni, A; Fantuzzi, E

    1996-09-01

    In pelvic irradiation, the small bowel portion included in the planning treatment volume is one of the major factors of acute enteropathy. Three different methods are used to calculate the bowel volume: Gallagher's grid method and two systems based on specific algorithms using CT data. We compared the results of these different methods in a series of nine patients submitted to treatment volume planning simulation for pelvic irradiation, after oral barium administration. The small bowel volumes were calculated with the grid method on orthogonal radiographs. About one hour later, the patients were submitted to CT for radiotherapy planning. The small bowel regions to be irradiated were drawn manually on all CT slices on a Varian Cadplan 2.62 console. Two different algorithms were used to calculate the small bowel volumes: one of them based on polyhedral and the other on cylindric approximation. The average volumes, the variance and the determination coefficient with linear and polynomial regression were in substantial statistical agreement in the three series; the correlation index between the grid and the CT methods ranged 0.84-0.87. Therefore, the authors believe that enteric side-effects can be correlated with the irradiated small bowel volume, independent of the calculation method.

  10. A comparison of muscle thin filament models obtained from electron microscopy reconstructions and low-angle X-ray fibre diagrams from non-overlap muscle.

    PubMed

    Poole, Katrina J V; Lorenz, Michael; Evans, Gwyndaf; Rosenbaum, Gerd; Pirani, Alnoor; Craig, Roger; Tobacman, Larry S; Lehman, William; Holmes, Kenneth C

    2006-08-01

    The regulation of striated muscle contraction involves changes in the interactions of troponin and tropomyosin with actin thin filaments. In resting muscle, myosin-binding sites on actin are thought to be blocked by the coiled-coil protein tropomyosin. During muscle activation, Ca2+ binding to troponin alters the tropomyosin position on actin, resulting in cyclic actin-myosin interactions that accompany muscle contraction. Evidence for this steric regulation by troponin-tropomyosin comes from X-ray data [Haselgrove, J.C., 1972. X-ray evidence for a conformational change in the actin-containing filaments of verterbrate striated muscle. Cold Spring Habor Symp. Quant. Biol. 37, 341-352; Huxley, H.E., 1972. Structural changes in actin and myosin-containing filaments during contraction. Cold Spring Habor Symp. Quant. Biol. 37, 361-376; Parry, D.A., Squire, J.M., 1973. Structural role of tropomyosin in muscle regulation: analysis of the X-ray diffraction patterns from relaxed and contracting muscles. J. Mol. Biol. 75, 33-55] and electron microscope (EM) data [Spudich, J.A., Huxley, H.E., Finch, J., 1972. Regulation of skeletal muscle contraction. II. Structural studies of the interaction of the tropomyosin-troponin complex with actin. J. Mol. Biol. 72, 619-632; O'Brien, E.J., Gillis, J.M., Couch, J., 1975. Symmetry and molecular arrangement in paracrystals of reconstituted muscle thin filaments. J. Mol. Biol. 99, 461-475; Lehman, W., Craig, R., Vibert, P., 1994. Ca2+-induced tropomyosin movement in Limulus thin filaments revealed by three-dimensional reconstruction. Nature 368, 65-67] each with its own particular strengths and limitations. Here we bring together some of the latest information from EM analysis of single thin filaments from Pirani et al. [Pirani, A., Xu, C., Hatch, V., Craig, R., Tobacman, L.S., Lehman, W. (2005). Single particle analysis of relaxed and activated muscle thin filaments. J. Mol. Biol. 346, 761-772], with synchrotron X-ray data from non

  11. Thyroid gland volume of schoolchildren in the North of Iran: Comparison with other studies

    PubMed Central

    Kalantari, Saeed; Moghadam, Masrur Vahabi

    2015-01-01

    Background: Few studies have shown the limitation of the World Health Organization (WHO)/ International Council for the Control of Iodine Deficiency (ICCIDD)-adopted thyroid gland volume references as universal normative values for thyroid gland volume. So we decided to measure thyroid gland volume by sonography in schoolchildren in Rasht, Gilan Province, Iran — Rasht is a metropolitan city on the Caspian Sea coast — and compare them to WHO normative values. Materials and Methods: In a cross-sectional study, 2,522 schoolchildren, aged 6-13 years, in Rasht, Gilan Province, Iran were selected by multistage random sampling. Data were collected on their age, sex, weight, height, body surface area (BSA), and thyroid gland size by palpation and sonography. The terminal phalange of thumb finger volume was calculated with the same formula used in sonography, for the thyroid gland in 1,085 of these cases. Results: Goiter prevalence was 64% (1613 cases) by palpation, 76.1% (1228 subjects) grade I and 23.9% (385 cases) grade II. The mean thyroid gland volume in girls was more than boys (3.67 ± 1.89 mL vs 3.41 ± 1.58 mL, P < 0.0001). According to the 1997 WHO thyroid gland volume reference, none of the children had goiter based on BSA and age even in those with grade II goiters (23.9%). In contrast, the median thyroid gland volume in our cases was larger than the 2004 WHO reference. The best single predictor of thyroid gland volume was age (R2 = 0.391, P < 0.0001) followed by BSA (R2 = 0.151, P < 0.0001). There was also a significant difference between thyroid gland and finger volume in all grades of goiter and grade II goiters (3 ± 1.4 mL vs 9.59 ± 2.4 mL; P < 0.0001. 4.3 ± 1.4 mL vs 9.3 ± 2.5 mL; P < 0.0001). Conclusion: The WHO standards for thyroid gland volume by sonography may underestimate or overestimate the goiter prevalence in many areas and populations. Finger volume was much larger than thyroid gland volume in even visible goiters. PMID:26941811

  12. Thyroid gland volume of schoolchildren in the North of Iran: Comparison with other studies.

    PubMed

    Kalantari, Saeed; Moghadam, Masrur Vahabi

    2015-11-01

    Few studies have shown the limitation of the World Health Organization (WHO)/ International Council for the Control of Iodine Deficiency (ICCIDD)-adopted thyroid gland volume references as universal normative values for thyroid gland volume. So we decided to measure thyroid gland volume by sonography in schoolchildren in Rasht, Gilan Province, Iran - Rasht is a metropolitan city on the Caspian Sea coast - and compare them to WHO normative values. In a cross-sectional study, 2,522 schoolchildren, aged 6-13 years, in Rasht, Gilan Province, Iran were selected by multistage random sampling. Data were collected on their age, sex, weight, height, body surface area (BSA), and thyroid gland size by palpation and sonography. The terminal phalange of thumb finger volume was calculated with the same formula used in sonography, for the thyroid gland in 1,085 of these cases. Goiter prevalence was 64% (1613 cases) by palpation, 76.1% (1228 subjects) grade I and 23.9% (385 cases) grade II. The mean thyroid gland volume in girls was more than boys (3.67 ± 1.89 mL vs 3.41 ± 1.58 mL, P < 0.0001). According to the 1997 WHO thyroid gland volume reference, none of the children had goiter based on BSA and age even in those with grade II goiters (23.9%). In contrast, the median thyroid gland volume in our cases was larger than the 2004 WHO reference. The best single predictor of thyroid gland volume was age (R (2) = 0.391, P < 0.0001) followed by BSA (R (2) = 0.151, P < 0.0001). There was also a significant difference between thyroid gland and finger volume in all grades of goiter and grade II goiters (3 ± 1.4 mL vs 9.59 ± 2.4 mL; P < 0.0001. 4.3 ± 1.4 mL vs 9.3 ± 2.5 mL; P < 0.0001). The WHO standards for thyroid gland volume by sonography may underestimate or overestimate the goiter prevalence in many areas and populations. Finger volume was much larger than thyroid gland volume in even visible goiters.

  13. The rate of force development scaling factor (RFD-SF): protocol, reliability, and muscle comparisons.

    PubMed

    Bellumori, Maria; Jaric, Slobodan; Knight, Christopher A

    2011-07-01

    Performing a set of isometric muscular contractions to varied amplitudes with instructions to generate force most rapidly reveals a strong linear relationship between peak forces (PF) achieved and corresponding peak rates of force development (RFD). The slope of this relationship, termed the RFD scaling factor (RFD-SF), quantifies the extent to which RFD scales with contraction amplitude. Such scaling allows relative invariance in the time required to reach PF regardless of contraction size. Considering the increasing use of this relationship to study quickness and consequences of slowness in older adults and movement disorders, our purpose was to further develop the protocol to measure RFD-SF. Fifteen adults (19-28 years) performed 125 rapid isometric contractions to a variety of force levels in elbow extensors, index finger abductors, and knee extensors, on 2 days. Data were used to determine (1) how the number of pulses affects computation of the RFD-SF, (2) day-to-day reliability of the RFD-SF, and (3) the nature of RFD-SF differences between diverse muscle groups. While sensitive to the number of pulses used in its computation (P<.05), RFD-SF was reliable when computed with >50 pulses (ICC>.7) and more so with 100-125 pulses (ICC=.8-.92). Despite differences in size and function across muscles, RFD-SF was generally similar (i.e., only 8.5% greater in elbow extensors than in index finger abductors and knee extensors; P=.049). Results support this protocol as a reliable means to assess how RFD scales with PF in rapid isometric contractions as well as a simple, non-invasive probe into neuromuscular health.

  14. A Comparison of Cough Assistance Techniques in Patients with Respiratory Muscle Weakness

    PubMed Central

    Kim, Sun Mi; Choi, Won Ah; Won, Yu Hui

    2016-01-01

    Purpose To assess the ability of a mechanical in-exsufflator (MI-E), either alone or in combination with manual thrust, to augment cough in patients with neuromuscular disease (NMD) and respiratory muscle dysfunction. Materials and Methods For this randomized crossover single-center controlled trial, patients with noninvasive ventilator-dependent NMD were recruited. The primary outcome was peak cough flow (PCF), which was measured in each patient after a cough that was unassisted, manually assisted following a maximum insufflation capacity (MIC) maneuver, assisted by MI-E, or assisted by manual thrust plus MI-E. The cough augmentation techniques were provided in random order. PCF was measured using a new device, the Cough Aid. Results All 40 enrolled participants (37 males, three females; average age, 20.9±7.2 years) completed the study. The mean (standard deviation) PCFs in the unassisted, manually assisted following an MIC maneuver, MI-E-assisted, and manual thrust plus MI-E-assisted conditions were 95.7 (40.5), 155.9 (53.1), 177.2 (33.9), and 202.4 (46.6) L/min, respectively. All three interventions significantly improved PCF. However, manual assistance following an MIC maneuver was significantly less effective than MI-E alone. Manual thrust plus MI-E was significantly more effective than both of these interventions. Conclusion In patients with NMD and respiratory muscle dysfunction, MI-E alone was more effective than manual assistance following an MIC maneuver. However, MI-E used in conjunction with manual thrust improved PCF even further. PMID:27593879

  15. A comparison of the excitability of motor axons innervating the APB and ADM muscles.

    PubMed

    Murray, J E; Jankelowitz, S K

    2011-11-01

    Threshold tracking allows the non-invasive assessment of axonal excitability. This study aimed to determine whether axonal excitability of the motor axons of the median nerve (to APB) and ulnar nerve (to ADM) to the small muscles of the hands is sufficiently similar to be interchangeable; confirm the feasibility and reproducibility of ulnar studies and obtain control data for a young population for this site of stimulation. Twenty normal subjects between the ages of 23-43 were studied using the TRONDF protocol of QTRACS, (©Prof Hugh Bostock, London). The median and ulnar nerves were stimulated at the wrist and the compound muscle action potentials were recorded from abductor pollicis brevis and abductor digiti minimi, respectively. Repeat studies were performed in four subjects to confirm reproducibility of the recordings. Stimulus intensity was greater and strength duration time constant was longer for the median nerve. Threshold electrotonus showed there was a greater change in threshold in the hyperpolarising direction for the median nerve compared with the ulnar nerve. There was however little difference in the recovery cycle and current threshold relationship. Although recovery cycles and the current thresholds are similar for APB and ADM, there are definite differences in stimulus threshold, SDTC and threshold electrotonus which question the interchangeability of studies for these two sites. This study demonstrates reproducibility of motor axonal excitability studies of the ulnar nerve at the wrist, provides young control data for this site of stimulation and suggests that although certain excitability indices are similar for the median nerve to APB and ulnar nerve to ADM there are definite differences making the interchangeability of the data questionable. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  16. Effect of Microcurrent Stimulation on Delayed-Onset Muscle Soreness: A Double-Blind Comparison

    PubMed Central

    Allen, Jennifer D.; Mattacola, Carl G.; Perrin, David H.

    1999-01-01

    Objective: To examine the efficacy of microcurrent electrical neuromuscular stimulation (MENS) treatment on pain and loss of range of motion (ROM) associated with delayed-onset muscle soreness (DOMS). Design and Setting: We assigned subjects to 1 of 2 groups. Group 1 received treatment with microcurrent stimulation (200 μA, 30 Hz, for 10 minutes, then 100 μA, 0.3 Hz, for 10 minutes) 24, 48, and 72 hours after DOMS induction. Group 2 served as a sham group and was treated using a machine altered by the manufacturer so that no current could flow through the electrodes. Subjects: DOMS was induced in the biceps brachii of the nondominant arm of 18 subjects (3 males, 15 females: age = 20.33 ± 2.3 years, ht = 170.81 ± 7.3 cm, wt = 69.61 ± 13.1 kg). Dominance was defined as the arm used by the subject to throw a ball. Measurements: Subjective pain and active elbow extension ROM were evaluated before and after treatment each day. Two methods were used to assess pain: constant pressure using a weighted Orthoplast sphere and full elbow extension to the limit of pain tolerance. Subjective pain was measured with a graphic rating scale and active elbow extension ROM using a standard, plastic, double-armed goniometer. Three repeated-measures ANOVAs (between-subjects variable was group, within- subjects variables were day and test) were used to assess ROM and pain scores for the 2 groups. Results: We found no significant difference in the measurement of subjective pain scores or elbow extension ROM when the MENS group was compared with the sham group. Conclusions: Our results indicate that the MENS treatment, within the parameters used for this experiment, was not effective in reducing the pain or loss of ROM associated with delayed-onset muscle soreness. PMID:16558582

  17. Effect of microcurrent stimulation on delayed-onset muscle soreness: a double-blind comparison.

    PubMed

    Allen, J D; Mattacola, C G; Perrin, D H

    1999-10-01

    To examine the efficacy of microcurrent electrical neuromuscular stimulation (MENS) treatment on pain and loss of range of motion (ROM) associated with delayed-onset muscle soreness (DOMS). We assigned subjects to 1 of 2 groups. Group 1 received treatment with microcurrent stimulation (200 muA, 30 Hz, for 10 minutes, then 100 muA, 0.3 Hz, for 10 minutes) 24, 48, and 72 hours after DOMS induction. Group 2 served as a sham group and was treated using a machine altered by the manufacturer so that no current could flow through the electrodes. DOMS was induced in the biceps brachii of the nondominant arm of 18 subjects (3 males, 15 females: age = 20.33 +/- 2.3 years, ht = 170.81 +/- 7.3 cm, wt = 69.61 +/- 13.1 kg). Dominance was defined as the arm used by the subject to throw a ball. Subjective pain and active elbow extension ROM were evaluated before and after treatment each day. Two methods were used to assess pain: constant pressure using a weighted Orthoplast sphere and full elbow extension to the limit of pain tolerance. Subjective pain was measured with a graphic rating scale and active elbow extension ROM using a standard, plastic, double-armed goniometer. Three repeated-measures ANOVAs (between-subjects variable was group, within- subjects variables were day and test) were used to assess ROM and pain scores for the 2 groups. We found no significant difference in the measurement of subjective pain scores or elbow extension ROM when the MENS group was compared with the sham group. Our results indicate that the MENS treatment, within the parameters used for this experiment, was not effective in reducing the pain or loss of ROM associated with delayed-onset muscle soreness.

  18. Comparison of two stretching methods and optimization of stretching protocol for the piriformis muscle.

    PubMed

    Gulledge, Brett M; Marcellin-Little, Denis J; Levine, David; Tillman, Larry; Harrysson, Ola L A; Osborne, Jason A; Baxter, Blaise

    2014-02-01

    Piriformis syndrome is an uncommon diagnosis for a non-discogenic form of sciatica whose treatment has traditionally focused on stretching the piriformis muscle (PiM). Conventional stretches include hip flexion, adduction, and external rotation. Using three-dimensional modeling, we quantified the amount of (PiM) elongation resulting from two conventional stretches and we investigated by use of a computational model alternate stretching protocols that would optimize PiM stretching. Seven subjects underwent three CT scans: one supine, one with hip flexion, adduction, then external rotation (ADD stretch), and one with hip flexion, external rotation, then adduction (ExR stretch). Three-dimensional bone models were constructed from the CT scans. PiM elongation during these stretches, femoral neck inclination, femoral head anteversion, and trochanteric anteversion were measured. A computer program was developed to map PiM length over a range of hip joint positions and was validated against the measured scans. ExR and ADD stretches elongated the PiM similarly by approximately 12%. Femoral head and greater trochanter anteversion influenced PiM elongation. Placing the hip joints in 115° of hip flexion, 40° of external rotation and 25° of adduction or 120° of hip flexion, 50° of external rotation and 30° of adduction increased PiM elongation by 30-40% compared to conventional stretches (15.1 and 15.3% increases in PiM muscle length, respectively). ExR and ADD stretches elongate the PiM similarly and therefore may have similar clinical effectiveness. The optimized stretches led to larger increases in PiM length and may be more easily performed by some patients due to increased hip flexion.

  19. Validation of Blood Volume Fraction Quantification with 3D Gradient Echo Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Porcine Skeletal Muscle

    PubMed Central

    Söhner, Anika; Maaß, Marc; Sauerwein, Wolfgang; Möllmann, Dorothe; Baba, Hideo Andreas; Kramer, Martin; Lüdemann, Lutz

    2017-01-01

    The purpose of this study was to assess the accuracy of fractional blood volume (vb) estimates in low-perfused and low-vascularized tissue using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). The results of different MRI methods were compared with histology to evaluate the accuracy of these methods under clinical conditions. vb was estimated by DCE-MRI using a 3D gradient echo sequence with k-space undersampling in five muscle groups in the hind leg of 9 female pigs. Two gadolinium-based contrast agents (CA) were used: a rapidly extravasating, extracellular, gadolinium-based, low-molecular-weight contrast agent (LMCA, gadoterate meglumine) and an extracellular, gadolinium-based, albumin-binding, slowly extravasating blood pool contrast agent (BPCA, gadofosveset trisodium). LMCA data were evaluated using the extended Tofts model (ETM) and the two-compartment exchange model (2CXM). The images acquired with administration of the BPCA were used to evaluate the accuracy of vb estimation with a bolus deconvolution technique (BD) and a method we call equilibrium MRI (EqMRI). The latter calculates the ratio of the magnitude of the relaxation rate change in the tissue curve at an approximate equilibrium state to the height of the same area of the arterial input function (AIF). Immunohistochemical staining with isolectin was used to label endothelium. A light microscope was used to estimate the fractional vascular area by relating the vascular region to the total tissue region (immunohistochemical vessel staining, IHVS). In addition, the percentage fraction of vascular volume was determined by multiplying the microvascular density (MVD) with the average estimated capillary lumen, π(d2)2, where d = 8μm is the assumed capillary diameter (microvascular density estimation, MVDE). Except for ETM values, highly significant correlations were found between most of the MRI methods investigated. In the cranial thigh, for example, the vb medians (interquartile range

  20. Validation of Blood Volume Fraction Quantification with 3D Gradient Echo Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Porcine Skeletal Muscle.

    PubMed

    Hindel, Stefan; Söhner, Anika; Maaß, Marc; Sauerwein, Wolfgang; Möllmann, Dorothe; Baba, Hideo Andreas; Kramer, Martin; Lüdemann, Lutz

    2017-01-01

    The purpose of this study was to assess the accuracy of fractional blood volume (vb) estimates in low-perfused and low-vascularized tissue using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). The results of different MRI methods were compared with histology to evaluate the accuracy of these methods under clinical conditions. vb was estimated by DCE-MRI using a 3D gradient echo sequence with k-space undersampling in five muscle groups in the hind leg of 9 female pigs. Two gadolinium-based contrast agents (CA) were used: a rapidly extravasating, extracellular, gadolinium-based, low-molecular-weight contrast agent (LMCA, gadoterate meglumine) and an extracellular, gadolinium-based, albumin-binding, slowly extravasating blood pool contrast agent (BPCA, gadofosveset trisodium). LMCA data were evaluated using the extended Tofts model (ETM) and the two-compartment exchange model (2CXM). The images acquired with administration of the BPCA were used to evaluate the accuracy of vb estimation with a bolus deconvolution technique (BD) and a method we call equilibrium MRI (EqMRI). The latter calculates the ratio of the magnitude of the relaxation rate change in the tissue curve at an approximate equilibrium state to the height of the same area of the arterial input function (AIF). Immunohistochemical staining with isolectin was used to label endothelium. A light microscope was used to estimate the fractional vascular area by relating the vascular region to the total tissue region (immunohistochemical vessel staining, IHVS). In addition, the percentage fraction of vascular volume was determined by multiplying the microvascular density (MVD) with the average estimated capillary lumen, [Formula: see text], where d = 8μm is the assumed capillary diameter (microvascular density estimation, MVDE). Except for ETM values, highly significant correlations were found between most of the MRI methods investigated. In the cranial thigh, for example, the vb medians

  1. Reduced volume and increased training intensity elevate muscle Na+-K+ pump alpha2-subunit expression as well as short- and long-term work capacity in humans.

    PubMed

    Bangsbo, Jens; Gunnarsson, Thomas P; Wendell, Jesper; Nybo, Lars; Thomassen, Martin

    2009-12-01

    The present study examined muscle adaptations and alterations in work capacity in endurance-trained runners as a result of a reduced amount of training combined with speed endurance training. For a 6- to 9-wk period, 17 runners were assigned to either a speed endurance group with a 25% reduction in the amount of training but including speed endurance training consisting of six to twelve 30-s sprint runs 3-4 times/wk (SET group n = 12) or a control group (n = 5), which continued the endurance training ( approximately 55 km/wk). For the SET group, the expression of the muscle Na(+)-K(+) pump alpha(2)-subunit was 68% higher (P < 0.05) and the plasma K(+) level was reduced (P < 0.05) during repeated intense running after 9 wk. Performance in a 30-s sprint test and the first of the supramaximal exhaustive runs was improved (P < 0.05) by 7% and 36%, respectively, after the speed endurance training period. In the SET group, maximal O(2) uptake was unaltered, but the 3-km (3,000-m) time was reduced (P < 0.05) from 10.4 +/- 0.1 to 10.1 +/- 0.1 min and the 10-km (10,000-m) time was improved from 37.3 +/- 0.4 to 36.3 +/- 0.4 min (means +/- SE). Muscle protein expression and performance remained unaltered in the control group. The present data suggest that both short- and long-term exercise performances can be improved with a reduction in training volume if speed endurance training is performed and that the Na(+)-K(+) pump plays a role in the control of K(+) homeostasis and in the development of fatigue during repeated high-intensity exercise.

  2. Fish muscle: the exceptional case of Notothenioids.

    PubMed

    Fernández, Daniel A; Calvo, Jorge

    2009-03-01

    Fish skeletal muscle is an excellent model for studying muscle structure and function, since it has a very well-structured arrangement with different fiber types segregated in the axial and pectoral fin muscles. The morphological and physiological characteristics of the different muscle fiber types have been studied in several teleost species. In fish muscle, fiber number and size varies with the species considered, limiting fish maximum final length due to constraints in metabolites and oxygen diffusion. In this work, we analyze some special characteristics of the skeletal muscle of the suborder Notothenioidei. They experienced an impressive radiation inside Antarctic waters, a stable and cold environment that could account for some of their special characteristics. The number of muscle fibers is very low, 12,700-164,000, in comparison to 550,000-1,200,000 in Salmo salar of similar sizes. The size of the fibers is very large, reaching 600 microm in diameter, while for example Salmo salar of similar sizes have fibers of 220 microm maximum diameter. Evolutionary adjustment in cell cycle length for working at low temperature has been shown in Harpagifer antarcticus (111 h at 0 degrees C), when compared to the closely related sub-Antarctic species Harpagifer bispinis (150 h at 5 degrees C). Maximum muscle fiber number decreases towards the more derived notothenioids, a trend that is more related to phylogeny than to geographical distribution (and hence water temperature), with values as low as 3,600 in Harpagifer bispinis. Mitochondria volume density in slow muscles of notothenioids is very high (reaching 0.56) and since maximal rates of substrate oxidation by mitochondria is not enhanced, at least in demersal notothenioids, volume density is the only means of overcoming thermal constraints on oxidative capacity. In brief, some characteristics of the muscles of notothenioids have an apparent phylogenetic component while others seem to be adaptations to low temperature.

  3. Comparison of water immersion and saline infusion as a means of inducing volume expansion in man

    NASA Technical Reports Server (NTRS)

    Epstein, M.; Pins, D. S.; Arrington, R.; Denunzio, A. G.; Engstrom, R.

    1975-01-01

    The study compares the natriuresis induced by head-out water immersion to that of a standard saline infusion and assesses the relative effectiveness of these two techniques as volume determinants of renal sodium and water handling in humans in a seated posture. The data obtained show that the volume stimulus of immersion is identical to that of standard saline-induced extracellular fluid volume expansion (ECVE) in normal seated subjects. The ability of head-out water immersion to induce a natriuresis without a concomitant increase in total blood volume and with a decrease in body weight suggests that water immersion may be preferred as an investigative tool for assessing the effects of ECVE in man.

  4. Comparison of premodulated interferential and pulsed current electrical stimulation in prevention of deep muscle atrophy in rats.

    PubMed

    Tanaka, Minoru; Hirayama, Yusuke; Fujita, Naoto; Fujino, Hidemi

    2013-04-01

    The goal of this study was to compare the effects of electrical stimulation using pulsed current (PC) and premodulated interferential current (IC) on prevention of muscle atrophy in the deep muscle layer of the calf. Rats were randomly divided into 3 treatment groups: control, hindlimb unloading for 2 weeks (HU), and HU plus electrical stimulation for 2 weeks. The animals in the electrical stimulation group received therapeutic stimulation of the left (PC) or right (IC) calf muscles twice a day during the unloading period. Animals undergoing HU for 2 weeks exhibited significant loss of muscle mass, decreased cross-sectional area (CSA) of muscle fibers, and increased expression of ubiquitinated proteins in the gastrocnemius and soleus muscles compared with control animals. Stimulation with PC attenuated the effects on the muscle mass, fiber CSA, and ubiquitinated proteins in the gastrocnemius muscle. However, PC stimulation failed to prevent atrophy of the deep layer of the gastrocnemius muscle and the soleus muscle. In contrast, stimulation with IC inhibited atrophy of both the gastrocnemius and soleus muscles. In addition, the IC protocol inhibited the HU-induced increase in ubiquitinated protein expression in both gastrocnemius and soleus muscles. These results suggest that electrical stimulation with IC is more effective than PC in preventing muscle atrophy in the deep layer of limb muscles.

  5. [THE ROLE OF HYDROGEN SULFIDE IN VOLUME-DEPENDENT MECHANISMS OF REGULATION OF VASCULAR SMOOTH MUSCLE CELLS CONTRACTILE ACTIVITY].

    PubMed

    Smagliy, L V; Gusakova, S V; Birulina, Yu G; Kovalev, I V; Orlov, S N

    2015-04-01

    The hydrogen sulfide (H2S) influence on the contractile activity of vascular smooth muscle cells (SMC) was studied on endothelium-denuded aortic ring segments of male Wistar rats with method of mechanography. Contractions of SMS were induced by incubation in high potassium solution as well as in hyper-, hypo- and isosmotic solutions. 5-100 LM of H2S donor--sodium hydrosulfide (NaHS) increased mechanical tension of SMC precontracted with high potassium solution that was abolished by bumetanide--the inhibitor of Na+, K+, 2Cl(-) -cotransporter (NKCC), but 100-1000 microM of NaHS relaxed SMS. NaHS (10 microM) increased the amplitude of hyper- and isosmotic contraction, but not of hyposmotic contraction. NaHS (ImM) decreased the amplitude of hyper-, iso-, and hyposmotic contractions. The direct measurements of NKCC activity with radionuclide method showed an increase in NKCC activity under the action of 5-100 microM of NaHS. These findings suggest that low concentrations of H2S participate in the NKCC activation. This mechanism underlines constrictive action of H2S on smooth muscle cells.

  6. Comparison of the Short-Term Outcomes after Postisometric Muscle Relaxation or Kinesio Taping Application for Normalization of the Upper Trapezius Muscle Tone and the Pain Relief: A Preliminary Study

    PubMed Central

    Ptaszkowski, Kuba; Slupska, Lucyna; Paprocka-Borowicz, Małgorzata; Kołcz-Trzęsicka, Anna; Zwierzchowski, Kamil; Halska, Urszula; Przestrzelska, Monika; Mucha, Dariusz; Rosińczuk, Joanna

    2015-01-01

    The main purpose of the study was to evaluate the resting bioelectrical activity of the upper trapezius muscle (the UT muscle) before and after one of the two interventions: postisometric muscle relaxation (PIR) and Kinesio Taping (KT). Moreover a comparison between group results was conducted. From the initial 61 volunteers, 52 were selected after exclusion criteria and were allocated randomly to 2 groups: PIR group and KT group. Outcome measures were assessed at baseline and completion of the intervention. The primary outcome measure was change in bioelectrical activity of UT muscle evaluated by surface electromyography (sEMG). Secondary outcomes included subjective assessment of pain using visual analogue scale (VAS). Significant differences were found only in KT group: the average resting bioelectrical activity decreased by 0.8 μV (p = 0.0237) and the average VAS result reduced by 2.0 points (p = 0.0001). Greater decrease of VAS results was recorded in KT group compared to PIR group (p = 0.0010). Both PIR and KT intervention did not influence significantly the resting bioelectrical activity of UT muscle. KT application was better for pain relief in the studied sample compared with PIR intervention. PMID:26347792

  7. A comparison of maximum cystometric bladder capacity with maximum environmental voided volumes.

    PubMed

    Yoon, E; Swift, S

    1998-01-01

    The aim of the study was, to determine whether maximum cystometric capacity accurately reflects the maximum functional bladder volume in women with urinary incontinence. We performed a retrospective chart review involving 85 women between the ages of 22 and 89 with primary complaints of urinary incontinence. The maximum cystometric capacity as determined by cystometry was compared with the maximum environmental voided volumes as recorded in a 24-hour voiding diary, using Pearson's correlation coefficients and paired t-tests. Patients diagnosed as having a small bladder capacity (< 300 ml maximum volume) based on cystometry were also examined with contingency table analysis to determine whether the bladder volumes in the voiding diaries supported the diagnosis of a small bladder. In 85 subjects the average maximum cystometric capacity was 14.7% less than the maximum volume recorded in the voiding diary. The correlation between the maximum cystometric capacity and maximum functional bladder volume was r = 0.473 (P < 0.001). However, there was a statistically significant difference between the two volumes by paired t-test analysis (P = 0.006). Using cystometry to diagnose small bladder capacity showed a sensitivity of 62.9% and a specificity of 71.2% when using voiding diary volumes as the criterion standard. The positive predictive value was 51.4% and the negative predictive value was 84.0%. These results suggest that whereas the maximum bladder capacity measured by cystometry correlates with maximum environmental bladder capacity as determined by 24-hour voiding diaries, there is a statistically significant difference. The diagnosis of a small bladder should not be based on office cystometry alone.

  8. Comparison of hematoma shape and volume estimates in warfarin versus non-warfarin-related intracerebral hemorrhage.

    PubMed

    Sheth, Kevin N; Cushing, Tracy A; Wendell, Lauren; Lev, Michael H; Romero, Javier M; Schwab, Kristin; Smith, Eric E; Greenberg, Steven M; Rosand, Jonathan; Goldstein, Joshua N

    2010-02-01

    Hematoma volume is a major determinant of outcome in patients with intracerebral hemorrhage (ICH). Accurate volume measurements are critical for predicting outcome and are thought to be more difficult in patients with oral anticoagulation-related ICH (OAT-ICH) due to a higher frequency of irregular shape. We examined hematoma shape and methods of volume assessment in patients with OAT-ICH. We performed a case-control analysis of a prospectively identified cohort of consecutive patients with ICH. We retrospectively reviewed 50 consecutive patients with OAT-ICH and 50 location-matched non-OAT-ICH controls. Two independent readers analyzed CT scans for hematoma shape and volume using both ABC/2 and ABC/3 methods. Readers were blinded to all clinical variables including warfarin status. Gold-standard ICH volumes were determined using validated computer-assisted planimetry. Within this cohort, median INR in patients with OAT-ICH was 3.2. Initial ICH volume was not significantly different between non-OAT-ICH and OAT-ICH (35 +/- 38 cc vs. 53 +/- 56 cc, P = 0.4). ICH shape did not differ by anticoagulation status (round shape in 10% of OAT-ICH vs. 16% of non-OAT-ICH, P = 0.5). The ABC/3 calculation underestimated median volume by 9 (3-28) cc, while the ABC/2 calculation did so by 4 (0.8-12) cc. Hematoma shape was not statistically significantly different in patients with OAT-ICH. Among bedside approaches, the standard ABC/2 method offers reasonable approximation of hematoma volume in OAT-ICH and non-OAT-ICH.

  9. COMPARISON OF VOLUMES OCCUPIED BY DIFFERENT INTERNAL FIXATION DEVICES FOR FEMORAL NECK FRACTURES

    PubMed Central

    Lauxen, Daniel; Schwartsmann, Carlos Roberto; Silva, Marcelo Faria; Spinelli, Leandro de Freitas; Strohaecker, Telmo Roberto; Souza, Ralf Wellis de; Zimmer, Cinthia Gabriely; Boschin, Leonardo Carbonera; Gonçalves, Ramiro Zilles; Yépez, Anthony Kerbes

    2015-01-01

    Objective: The objective of this paper is to measure the volume occupied by the most widely used internal fixation devices for treating femoral neck fractures, using the first 30, 40 and 50 mm of insertion of each screw as an approximation. The study aimed to observe which of these implants caused least bone aggression. Methods: Five types of cannulated screws and four types of dynamic hip screws (DHS) available on the Brazilian market were evaluated in terms of volume differences through water displacement. Results: Fixation with two cannulated screws presented significantly less volume than shown by DHS, for insertions of 30, 40 and 50 mm (p=0.01, 0.012 and 0.013, respectively), fixation with three screws did not show any statistically significant difference (p= 0.123, 0.08 and 0.381, respectively) and fixation with four cannulated screws presented larger volumes than shown by DHS (p=0.072, 0.161 and 0.033). Conclusions: Fixation of the femoral neck with two cannulated screws occupied less volume than DHS, with a statistically significant difference. The majority of screw combinations did not reach statistical significance, although fixation with four cannulated screws presented larger volumes on average than those occupied by DHS. PMID:27047886

  10. Relative activity of respiratory muscles during prescribed inspiratory muscle training in healthy people

    PubMed Central

    Jung, Ju-hyeon; Kim, Nan-soo

    2016-01-01

    [Purpose] This study aimed to determine the effects of different intensities of inspiratory muscle training on the relative respiratory muscle activity in healthy adults. [Subjects and Methods] Thirteen healthy male volunteers were instructed to perform inspiratory muscle training (0%, 40%, 60%, and 80% maximal inspiratory pressure) on the basis of their individual intensities. The inspiratory muscle training was performed in random order of intensities. Surface electromyography data were collected from the right-side diaphragm, external intercostal, and sternocleidomastoid, and pulmonary functions (forced expiratory volume in 1 s, forced vital capacity, and their ratio; peak expiratory flow; and maximal inspiratory pressure) were measured. [Results] Comparison of the relative activity of the diaphragm showed significant differences between the 60% and 80% maximal inspiratory pressure intensities and baseline during inspiratory muscle training. Furthermore, significant differences were found in sternocleidomastoid relative activity between the 60% and 80% maximal inspiratory pressure intensities and baseline during inspiratory muscle training. [Conclusion] During inspiratory muscle training in the clinic, the patients were assisted (verbally or through feedback) by therapists to avoid overactivation of their accessory muscles (sternocleidomastoid). This study recommends that inspiratory muscle training be performed at an accurate and appropriate intensity through the practice of proper deep breathing. PMID:27134409

  11. Relative activity of respiratory muscles during prescribed inspiratory muscle training in healthy people.

    PubMed

    Jung, Ju-Hyeon; Kim, Nan-Soo

    2016-03-01

    [Purpose] This study aimed to determine the effects of different intensities of inspiratory muscle training on the relative respiratory muscle activity in healthy adults. [Subjects and Methods] Thirteen healthy male volunteers were instructed to perform inspiratory muscle training (0%, 40%, 60%, and 80% maximal inspiratory pressure) on the basis of their individual intensities. The inspiratory muscle training was performed in random order of intensities. Surface electromyography data were collected from the right-side diaphragm, external intercostal, and sternocleidomastoid, and pulmonary functions (forced expiratory volume in 1 s, forced vital capacity, and their ratio; peak expiratory flow; and maximal inspiratory pressure) were measured. [Results] Comparison of the relative activity of the diaphragm showed significant differences between the 60% and 80% maximal inspiratory pressure intensities and baseline during inspiratory muscle training. Furthermore, significant differences were found in sternocleidomastoid relative activity between the 60% and 80% maximal inspiratory pressure intensities and baseline during inspiratory muscle training. [Conclusion] During inspiratory muscle training in the clinic, the patients were assisted (verbally or through feedback) by therapists to avoid overactivation of their accessory muscles (sternocleidomastoid). This study recommends that inspiratory muscle training be performed at an accurate and appropriate intensity through the practice of proper deep breathing.

  12. Comparison of palatability characteristics of beef gluteus medius and triceps brachii muscles.

    PubMed

    King, D A; Wheeler, T L; Shackelford, S D; Koohmaraie, M

    2009-01-01

    The objective of this experiment was to evaluate triceps brachii steaks as a substitute for gluteus medius steaks in foodservice and retail applications, including the effect of aging time and USDA quality grade on the palatability of both muscles. Top sirloin butts (n = 600) and shoulder clod arm roasts (n = 600) representing US Choice and US Select quality grades were selected at 48 h postmortem and aged for 7, 14, 21, 28, 35, or 42 d. Steaks were evaluated using a trained sensory panel, slice shear force, sarcomere length, and Western blotting of desmin measurements. Sarcomere length was measured only on steaks at 14 and 42 d. Triceps brachii and gluteus medius steaks were similar in tenderness rating at 7 and 14 d, but triceps brachii steaks aged longer were more tender (P < 0.05) than were gluteus medius steaks. Triceps brachii steaks reached ultimate tenderness values by 21 d. Gluteus medius steak tenderness ratings improved through 35 d, and at 42 d were similar to those given to triceps brachii steaks at 21 d. Sarcomere lengths were longer (P < 0.05) in triceps brachii than in gluteus medius (2.09 and 1.58 mum, respectively). Significant increases in desmin degradation were detected through 42 d in both muscles (30.9, 46.3, 50.6, 51.0, 57.6, and 64.1% at d 7, 14, 21, 28, 35, and 42 for gluteus medius and 28.9, 40.8, 49.3, 59.2, 61.8, and 71.9% at d 7, 14, 21, 28, 35, and 42 for triceps brachii). At 14 d, gluteus medius had more (P < 0.05) desmin degraded than triceps brachii, but by 28 d, desmin degradation was greater (P < 0.05) in triceps brachii. Quality grade had minimal effects on palatability traits. Desmin degradation contributed to gluteus medius tenderness variation (r = 0.36) across all aging times, but not at individual aging times. Sarcomere length contributed to variation in slice shear force values of gluteus medius at 14 and 42 d (r = -0.59 and -0.48, respectively). Sarcomere length contributed to triceps brachii tenderness variation at 14 d

  13. Stem Cell Antigen-1 in Skeletal Muscle Function

    PubMed Central

    Bernstein, Harold S.; Samad, Tahmina; Cholsiripunlert, Sompob; Khalifian, Saami; Gong, Wenhui; Ritner, Carissa; Aurigui, Julian; Ling, Vivian; Wilschut, Karlijn J.; Bennett, Stephen; Hoffman, Julien; Oishi, Peter

    2013-01-01

    Stem cell antigen-1 (Sca-1) is a member of the Ly-6 multigene family encoding highly homologous, glycosyl-phosphatidylinositol-anchored membrane proteins. Sca-1 is expressed on muscle-derived stem cells and myogenic precursors recruited to sites of muscle injury. We previously reported that inhibition of Sca-1 expression stimulated myoblast proliferation in vitro and regulated the tempo of muscle repair in vivo. Despite its function in myoblast expansion during muscle repair, a role for Sca-1 in normal, post-natal muscle has not been thoroughly investigated. We systematically compared Sca-1-/- (KO) and Sca-1+/+ (WT) mice and hindlimb muscles to elucidate the tissue, contractile, and functional effects of Sca-1 in young and aging animals. Comparison of muscle volume, fibrosis, myofiber cross-sectional area, and Pax7+ myoblast number showed little differences between ages or genotypes. Exercise protocols, however, demonstrated decreased stamina in KO versus WT mice, with young KO mice achieving results similar to aging WT animals. In addition, KO mice did not improve with practice, while WT animals demonstrated conditioning over time. Surprisingly, myomechanical analysis of isolated muscles showed that KO young muscle generated more force and experienced less fatigue. However, KO muscle also demonstrated incomplete relaxation with fatigue. These findings suggest that Sca-1 is necessary for muscle conditioning with exercise, and that deficient conditioning in Sca-1 KO animals becomes more pronounced with age. PMID:24042315

  14. Comparative anatomy, evolution, and homologies of tetrapod hindlimb muscles, comparison with forelimb muscles, and deconstruction of the forelimb-hindlimb serial homology hypothesis.

    PubMed

    Diogo, Rui; Molnar, Julia

    2014-06-01

    For more than two centuries, the idea that the forelimb and hindlimb are serially homologous structures has been accepted without serious question. This study presents the first detailed analysis of the evolution and homologies of all hindlimb muscles in representatives of each major tetrapod group and proposes a unifying nomenclature for these muscles. These data are compared with information obtained previously about the forelimb muscles of tetrapods and the muscles of other gnathostomes in order to address one of the most central and enigmatic questions in evolutionary and comparative anatomy: why are the pelvic and pectoral appendages of gnathostomes generally so similar to each other? An integrative analysis of the new myological data, combined with a review of recent paleontological, developmental, and genetic works and of older studies, does not support serial homology between the structures of these appendages. For instance, many of the strikingly similar forelimb and hindlimb muscles found in each major extant tetrapod taxon were acquired at different geological times and/or have different embryonic origins. These similar muscles are not serial homologues, but the result of evolutionary parallelism/convergence due to a complex interplay of ontogenetic, functional, topological, and phylogenetic constraints/factors. Copyright © 2014 Wiley Periodicals, Inc.

  15. Comparison of the Cross-Sectional Area of Longus Colli Muscle Between Patients With Cervical Radicular Pain and Healthy Controls.

    PubMed

    Noormohammadpour, Pardis; Dehghani-Firouzabadi, Azime; Mansournia, Mohammad Ali; Mohseni-Bandpei, Mohammad Ali; Moghaddam, Navid; Miri, Mojtaba; Kordi, Ramin

    2017-02-01

    Previous studies have shown atrophy of paravertebral lumbar muscles in patients with lumbar radicular pain and have proposed rehabilitative approaches based on these findings. However, changes in cervical paravertebral muscles in patients with cervical radicular pain are still unknown. The aim of this study was to compare the cross-sectional area (CSA) of the longus colli muscle (LCM) in patients with cervical radicular pain and healthy controls via ultrasound measurement. Case-control study. Outpatients who came for treatment to the neurosurgery clinic. A total of 20 patients with more than 4 weeks of cervical radicular pain and 20 healthy matched (for body mass index, age, and gender) control subjects. Ultrasound measurements. The CSA of the LCM at the level of C5-C6 was measured by ultrasound with the subject in supine position. Also, Neck Disability Index (NDI), and visual analogue scale (VAS) scores were reported by patients. An independent-sample t test was used for investigation of differences in CSA and other variables in both groups. A total of 20 patients with cervical radicular pain with a mean age of 42.4 years (standard deviation [SD] = 7 years) and 20 healthy matched controls with mean age of 40.7 years (SD = 7 years) participated in the study. Patients with cervical radicular pain showed smaller CSA of the LCM bilaterally compared with controls (mean difference: 0.37 [SD = 0.15]; P < .001). In the patient group, there were no significant differences between the CSA of the LCM in the involved and noninvolved sides. No correlations between the CSA of the LCM and VAS, Neck Disability Index, symptom duration, gender, BMI, and age of the patients were found. This is the first study to show via ultrasound assessment that patients with cervical radicular pain had smaller bilateral CSA of the LCM in comparison with healthy controls. It is also not clear whether atrophy of the LCM in patients with cervical radicular pain is a consequence or a cause of the

  16. Comparison between parameters of muscle performance and inflammatory biomarkers of non-sarcopenic and sarcopenic elderly women

    PubMed Central

    Lustosa, Lygia Paccini; Batista, Patrícia Parreira; Pereira, Daniele Sirineu; Pereira, Leani Souza Máximo; Scianni, Aline; Ribeiro-Samora, Giane Amorim

    2017-01-01

    Background Sarcopenia is a multifactorial geriatric syndrome with complex interrelationships. Increased plasma levels of inflammatory mediators increase the catabolic stimuli of the musculature, thereby causing a decrease in mass and muscular function. Objective The objective of this study was to compare the performance of the knee extensors test (by isokinetic dynamometer) and plasma levels of interleukin-6 (IL-6) and soluble receptors of tumor necrosis factor alpha (sTNFR1) between sarcopenics and non-sarcopenics community-dwelling elderly women residents of Brazil. Material and methods The diagnosis of sarcopenia included measurements of body composition (by densitometry with dual energy source of X-ray), handgrip strength (by Jamar® dynamometer), and the usual gait velocity according to the recommendations of the European Working Group on Sarcopenia in Older People. In both sarcopenics and non-sarcopenics elderly women, we evaluated the muscle function by knee extensors test (using an isokinetic dynamometer Byodex System 4 Pro®) at angular speeds of 60°/s and 180°/s) and also we evaluated the plasma concentrations of IL-6 and sTNFR1. Comparisons of muscle performance between groups were carried out using mixed factorial ANOVA with post hoc Bonferroni test; sTNFR1 and IL-6 variables were analyzed by applying Mann–Whitney U test. Results Statistical differences were observed between groups regarding muscle power (P=0.01), total work adjusted to body weight (P=0.01) at a rate of 180°/s, and plasma levels of sTNFR1 (P=0.01). Conclusion Sarcopenic elder women showed lower performance of the lower limbs, especially at a higher speed, predisposing these older women to greater vulnerability in functional activities that require agility and postural stability. Plasma levels of sTNFR1 were higher for non-sarcopenics elderlies. However, due to the observational nature of the study, it was impossible to infer causality among the variables surveyed. PMID:28814844

  17. Skeletal Muscle Pathology in X-Linked Myotubular Myopathy: Review With Cross-Species Comparisons

    PubMed Central

    Lawlor, Michael W.; Beggs, Alan H.; Buj-Bello, Ana; Childers, Martin K.; Dowling, James J.; James, Emma S.; Meng, Hui; Moore, Steven A.; Prasad, Suyash; Schoser, Benedikt; Sewry, Caroline A.

    2016-01-01

    X-linked myotubular myopathy (XLMTM) is a devastating, rare, congenital myopathy caused by mutations in the MTM1 gene, resulting in a lack of or dysfunction of the enzyme myotubularin. This leads to severe perinatal weakness and distinctive muscle pathology. It was originally thought that XLMTM was related to developmental arrest in myotube maturation; however, the generation and characterization of several animal models have significantly improved our understanding of clinical and pathological aspects of this disorder. Myotubularin is now known to participate in numerous cellular processes including endosomal trafficking, excitation-contraction coupling, cytoskeletal organization, neuromuscular junction structure, autophagy, and satellite cell proliferation and survival. The available vertebrate models of XLMTM, which vary in severity from complete absence to reduced functional levels of myotubularin, recapitulate features of the human disease to a variable extent. Understanding how pathological endpoints in animals with XLMTM translate to human patients will be essential to interpret preclinical treatment trials and translate therapies into human clinical studies. This review summarizes the published animal models of XLMTM, including those of zebrafish, mice, and dogs, with a focus on their pathological features as compared to those seen in human XLMTM patients. PMID:26823526

  18. Muscle metabolite accumulation following maximal exercise. A comparison between short-term and prolonged kayak performance.

    PubMed

    Tesch, P A; Karlsson, J

    1984-01-01

    Five elite flatwater kayak paddlers were studied during indoor simulated 500 and 10,000-m races, with performance times of 2 and 45 min, respectively. Muscle biopsies were obtained from the midportion of m. deltoideus immediately pre and post exercise. Concentrations of adenosine triphosphate (ATP), creatine phosphate (CP), glucose, glucose-6-phosphate (G-6-P), glycogen, and lactate were subsequently determined. Short term exercise resulted in statistically significant increases in glucose (P less than 0.001), G-6-P (P less than 0.05) and lactate (P less than 0.01) concentration concomitant with decreased CP (P less than 0.05) and glycogen (P less than 0.01). Following prolonged exercise, a non-significant elevation in glucose and a reduction (P less than 0.01) in glycogen were demonstrated. Evidently the metabolic demands for kayak competitions at 500 and 10,000 m are different. Thus, the energy contribution from glycolytic precursors and the anaerobic component is of greater relative importance in short distances than in exercise of long duration. A generalization of the findings to other athletic events of varying distances is proposed. The present data on arm-exercise is consistent with previous findings obtained in connection with leg exercises.

  19. Comparison of two sample preparation methods for analysis of organochlorine pesticides residues in fish muscle.

    PubMed

    Witczak, Agata; Patrzykąt, Agnieszka

    2011-01-01

    The aim of this study was to compare recoveries of organochlorine pesticides (heptachlor, α-HCH, β-HCH, γ-HCH, op'-DDD, pp'-DDD, pp'-DDE, op'-DDT, pp'-DDT) from fish muscle dried by two alternative methods: (i) grinding with anhydrous sodium sulphate and (ii) freeze drying. Pesticide residues content was determined by gas chromatography-mass spectrometry (GS-MS) method. For four pesticides (γ-HCH, α-HCH, heptachlor and pp;-DDD) in four of five fish species, higher recoveries were obtained from the freeze-dried samples. For five remaining pesticides, correlations between fish species and drying method were not found. The results of this study do not clearly indicate which drying method caused lower losses of analytes. Recoveries from the freeze-dried samples ranged from 69.9 to 117.6 %, while recoveries from the samples ground with sodium sulphate varied from 64.4 to 126.7 %. Either of the methods gave satisfactory recoveries and they both can be used interchangeably.

  20. Pulmonary blood volume measured by contrast enhanced ultrasound: a comparison with transpulmonary thermodilution.

    PubMed

    Herold, I H F; Soliman Hamad, M A; van Assen, H C; Bouwman, R A; Korsten, H H M; Mischi, M

    2015-07-01

    Blood volume quantification is essential for haemodynamic evaluation guiding fluid management in anaesthesia and intensive care practice. Ultrasound contrast agent (UCA)-dilution measured by contrast enhanced ultrasound (CEUS) can provide the UCA mean transit time (MTT) between the right and left heart, enabling the assessment of the intrathoracic blood volume (ITBV(UCA)). The purpose of the present study was to investigate the agreement between UCA-dilution using CEUS and transpulmonary thermodilution (TPTD) in vitro and in vivo. In an in vitro setup, with variable flows and volumes, we injected a double indicator, ice-cold saline with SonoVue(®), and performed volume measurements using transesophageal echo and thermodilution by PiCCO(®). In a pilot study, we assigned 17 patients undergoing elective cardiac surgery for pulmonary blood volume (PBV) measurement using TPTD by PiCCO(®) and ITBV by UCA-dilution. Correlation coefficients and Bland-Altman analysis were performed for all volume measurements. In vitro, 73 experimental MTT's were obtained using PiCCO(®) and UCA-dilution. The volumes by PiCCO(®) and UCA-dilution correlated with true volumes; r(s)=0.96 (95% CI, 0.93-0.97; P<0.0001) and r(s)=0.97 (95% CI, 0.95-0.98; P<0.0001), respectively. The bias of PBV by PiCCO(®) and ITBV(UCA) were -380 ml and -42 ml, respectively. In 16 patients, 86 measurements were performed. The correlation between PBV by PiCCO(®) and ITBV(UCA) was r(s)=0.69 (95% CI 0.55-0.79; P<0.0001). Bland-Altman analysis revealed a bias of -323 ml. ITBV assessment with CEUS seems a promising technique for blood volume measurement, which is minimally-invasive and bedside applicable. ISRCTN90330260. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Dose-volume-related dysphagia after constrictor muscles definition in head and neck cancer intensity-modulated radiation treatment.

    PubMed

    Mazzola, R; Ricchetti, F; Fiorentino, A; Fersino, S; Giaj Levra, N; Naccarato, S; Sicignano, G; Albanese, S; Di Paola, G; Alterio, D; Ruggieri, R; Alongi, F

    2014-12-01

    Dysphagia remains a side effect influencing the quality of life of patients with head and neck cancer (HNC) after radiotherapy. We evaluated the relationship between planned dose involvement and acute and late dysphagia in patients with HNC treated with intensity-modulated radiation therapy (IMRT), after a recontouring of constrictor muscles (PCs) and the cricopharyngeal muscle (CM). Between December 2011 and December 2013, 56 patients with histologically proven HNC were treated with IMRT or volumetric-modulated arc therapy. The PCs and CM were recontoured. Correlations between acute and late toxicity and dosimetric parameters were evaluated. End points were analysed using univariate logistic regression. An increasing risk to develop acute dysphagia was observed when constraints to the middle PCs were not respected [mean dose (Dmean) ≥50 Gy, maximum dose (Dmax) >60 Gy, V50 >70% with a p = 0.05]. The superior PC was not correlated with acute toxicity but only with late dysphagia. The inferior PC was not correlated with dysphagia; for the CM only, Dmax >60 Gy was correlated with acute dysphagia ≥ grade 2. According to our analysis, the superior PC has a major role, being correlated with dysphagia at 3 and 6 months after treatments; the middle PC maintains this correlation only at 3 months from the beginning of radiotherapy, but it does not have influence on late dysphagia. The inferior PC and CM have a minimum impact on swallowing symptoms. We used recent guidelines to define dose constraints of the PCs and CM. Two results emerge in the present analysis: the superior PC influences late dysphagia, while the middle PC influences acute dysphagia.

  2. Cell-volume-dependent vascular smooth muscle contraction: role of Na+, K+, 2Cl- cotransport, intracellular Cl- and L-type Ca2+ channels.

    PubMed

    Anfinogenova, Yana J; Baskakov, Mikhail B; Kovalev, Igor V; Kilin, Alexander A; Dulin, Nickolai O; Orlov, Sergei N

    2004-10-01

    This study elucidates the role of cell volume in contractions of endothelium-denuded vascular smooth muscle rings (VSMR) from the rat aorta. We observed that hyposmotic swelling as well as hyper- and isosmotic shrinkage led to VSMR contractions. Swelling-induced contractions were accompanied by activation of Ca2+ influx and were abolished by nifedipine and verapamil. In contrast, contractions of shrunken cells were insensitive to the presence of L-type channel inhibitors and occurred in the absence of Ca2+ o. Thirty minutes preincubation with bumetanide, a potent Na+, K+, CI- cotransport (NKCC) inhibitor, decreased Cl(-)i content, nifedipine-sensitive 45Ca uptake and contractions triggered by modest depolarization ([K+]o = 36 mM). Elevation of [K+]o to 66 mM completely abolished the effect of bumetanide on these parameters. Bumetanide almost completely abrogated phenylephrine-induced contraction, partially suppressed contractions triggered by hyperosmotic shrinkage, but potentiated contractions of isosmotically shrunken VSMR. Our results suggest that bumetanide suppresses contraction of modestly depolarized cells via NKCC inhibition and Cl(-)i-mediated membrane hyperpolarization, whereas augmented contraction of isosmotically shrunken VSMR by bumetanide is a consequence of suppression of NKCC-mediated regulatory volume increase. The mechanism of bumetanide inhibition of contraction of phenylephrine-treated and hyperosmotically shrunken VSMR should be examined further.

  3. Dose-volume relationships for moderate or severe neck muscle atrophy after intensity-modulated radiotherapy in patients with nasopharyngeal carcinoma

    PubMed Central

    Zhang, Lu-Lu; Wang, Xiao-Ju; Zhou, Guan-Qun; Tang, Ling-Long; Lin, Ai-Hua; Ma, Jun; Sun, Ying

    2015-01-01

    This study aimed to identify the dosimetric parameters and radiation dose tolerances associated with moderate or severe sternocleidomastoid muscle (SCM) atrophy after intensity-modulated radiotherapy (IMRT) in nasopharyngeal carcinoma (NPC). We retrospectively analysed 138 patients treated with IMRT between 2011 and 2012 for whom IMRT treatment plans and pretreatment and 3-year post-IMRT MRI scans were available. The association between mean dose (Dmean), maximum dose (Dmax), VX (% SCM volume that received more than X Gy), DX (dose to X% of the SCM volume) at X values of 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80 and SCM atrophy at 3 years after IMRT were analyzed. All dosimetric parameters, except V40, V50 and V80, were significantly associated with moderate or severe SCM atrophy. Multivariate analysis showed that V65 was an independent predictor of moderate or severe SCM atrophy (P < 0.001). Receiver operating characteristic (ROC) curve indicated a V65 of 21.47% (area under ROC curves, 0.732; P < 0.001) was the tolerated dose for moderate or severe SCM atrophy. We suggest a limit of 21.47% for V65 to optimize NPC treatment planning, whilst minimizing the risk of moderate or severe SCM atrophy. PMID:26678599

  4. Dose-volume relationships for moderate or severe neck muscle atrophy after intensity-modulated radiotherapy in patients with nasopharyngeal carcinoma.

    PubMed

    Zhang, Lu-Lu; Wang, Xiao-Ju; Zhou, Guan-Qun; Tang, Ling-Long; Lin, Ai-Hua; Ma, Jun; Sun, Ying

    2015-12-18

    This study aimed to identify the dosimetric parameters and radiation dose tolerances associated with moderate or severe sternocleidomastoid muscle (SCM) atrophy after intensity-modulated radiotherapy (IMRT) in nasopharyngeal carcinoma (NPC). We retrospectively analysed 138 patients treated with IMRT between 2011 and 2012 for whom IMRT treatment plans and pretreatment and 3-year post-IMRT MRI scans were available. The association between mean dose (Dmean), maximum dose (Dmax), VX (% SCM volume that received more than X Gy), DX (dose to X% of the SCM volume) at X values of 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80 and SCM atrophy at 3 years after IMRT were analyzed. All dosimetric parameters, except V40, V50 and V80, were significantly associated with moderate or severe SCM atrophy. Multivariate analysis showed that V65 was an independent predictor of moderate or severe SCM atrophy (P < 0.001). Receiver operating characteristic (ROC) curve indicated a V65 of 21.47% (area under ROC curves, 0.732; P < 0.001) was the tolerated dose for moderate or severe SCM atrophy. We suggest a limit of 21.47% for V65 to optimize NPC treatment planning, whilst minimizing the risk of moderate or severe SCM atrophy.

  5. A Comparison of Increases in Volume Load Over 8 Weeks of Low-Versus High-Load Resistance Training.

    PubMed

    Schoenfeld, Brad J; Ogborn, Dan; Contreras, Bret; Cappaert, Tom; Silva Ribeiro, Alex; Alvar, Brent A; Vigotsky, Andrew D

    2016-06-01

    It has been hypothesized that the ability to increase volume load (VL) via a progressive increase in the magnitude of load for a given exercise within a given repetition range could enhance the adaptive response to resistance training. The purpose of this study was to compare changes in volume load (VL) over eight weeks of resistance training (RT) in high-versus low-load protocols. Eighteen well-trained men were matched according to baseline strength were randomly assigned to either a low-load RT (LOW, n = 9) where 25 - 35 repetitions were performed per exercise, or a high-load RT (HIGH, n = 9) where 8 - 12 repetitions were performed per exercise. Both groups performed three sets of seven exercises for all major muscles three times per week on non-consecutive days. After adjusting for the pre-test scores, there was a significant difference between the two intervention groups on post-intervention total VL with a very large effect size (F (1, 15) = 16.598, P = .001, ηp(2) = .525). There was a significant relationship between pre-intervention and post-intervention total VL (F (1, 15) = 32.048, P < .0001, ηp(2) = .681) in which the pre-test scores explained 68% of the variance in the post-test scores. This study indicates that low-load RT results in greater accumulations in VL compared to high-load RT over the course of 8 weeks of training.

  6. Isokinetic muscle strength for ankle extensors and flexors: a comparison between elite sprint runners and swimmers.

    PubMed

    Ozçaldiran, B; Durmaz, B

    2008-09-01

    The aim of this study was to evaluate through isokinetic tests the muscular condition of ankles of elite sprint swimmers and elite sprint runners, and make comparisons within these groups. Fourteen elite swimmers and 8 elite runners were included in this cross-sectional study. The ankle extensors and flexors strength characteristics of elite sprinter athletes were tested at a slow (30 degrees/s) and a fast (120 degrees/s) speed using an isokinetic dynamometer. Subjects were assessed by one examiner on six separate days, within a 2-week period. A significant difference was noted between right and left sides for ankle joint flexors in runners at slow speed. Runners had higher left ankle flexion measures at 30 degrees/s and 120 degrees/s angular velocity than swimmers. There was no significant difference between the peak torques of the left and right sides at all angular velocities in swimmers. To our knowledge, this is the first study to assess the ankle flexors and extensors strength characteristics of elite sprinter swimmers making a comparison with elite sprinter runners. The findings presented in this study report the sport specific difference between the sprint swimmers and sprint runners. These values add a quantative dimension to rehabilitative and preventive sports medicine for elite sprinter runners and swimmers.

  7. Final report on regional supplementary comparison SIM.M.FF-S5: Volume of liquids at 50 mL

    NASA Astrophysics Data System (ADS)

    Morales, Abed; Malta, Dalni; Kornblit, Fernando; Ramírez, Ruben R.; Arias, Roberto; Trujillo, Sonia

    2012-01-01

    A regional supplementary comparison for the volume of liquid at 50 mL was conducted during October 2009 to June 2010 between the SIM members CENAM, INTI, INMETRO, INDECOPI and INTN. The transfer standard consisted of two 50 mL glass pycnometers, of the Gay Lussac type. CENAM acted as the pilot, collected the measurement results, analyzed the data and produced the comparison report. The median of all participants' results was used to calculate the regional comparison reference value because the result for one of the two pycnometers in one laboratory failed the chi-squared test at the 0.05 probability level. The measurements reported by the participants show an excellent overlap in four out of the five NMIs (-34×10-6 < Di < 29×10-6). The degree of equivalence obtained herein will be taken into account for the preparation of calibration and measurement capabilities claims from the participants. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the SIM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  8. Botox induced muscle paralysis rapidly degrades bone

    PubMed Central

    Warner, Sarah E.; Sanford, David A.; Becker, Blair A.; Bain, Steven D.; Srinivasan, Sundar; Gross, Ted S.

    2006-01-01

    The means by which muscle function modulates bone homeostasis is poorly understood. To begin to address this issue, we have developed a novel murine model of unilateral transient hindlimb muscle paralysis using botulinum toxin A (Botox). Female C57BL/6 mice (16 weeks) received IM injections of either saline or Botox (n = 10 each) in both the quadriceps and calf muscles of the right hindleg. Gait dysfunction was assessed by multi-observer inventory, muscle alterations were determined by wet mass, and bone alterations were assessed by micro-CT imaging at the distal femur, proximal tibia, and tibia mid-diaphysis. Profound degradation of both muscle and bone was observed within 21 days despite significant restoration of weight bearing function by 14 days. The muscle mass of the injected quadriceps and calf muscles was diminished −47.3% and −59.7%, respectively, vs. saline mice (both P < 0.001). The ratio of bone volume to tissue volume (BV/TV) within the distal femoral epiphysis and proximal tibial metaphysis of Botox injected limbs was reduced −43.2% and −54.3%, respectively, while tibia cortical bone volume was reduced −14.6% (all P < 0.001). Comparison of the contralateral non-injected limbs indicated the presence of moderate systemic effects in the model that were most probably associated with diminished activity following muscle paralysis. Taken as a whole, the micro-CT data implied that trabecular and cortical bone loss was primarily achieved by bone resorption. These data confirm the decisive role of neuromuscular function in mediating bone homeostasis and establish a model with unique potential to explore the mechanisms underlying this relation. Given the rapidly expanding use of neuromuscular inhibitors for indications such as pain reduction, these data also raise the critical need to monitor bone loss in these patients. PMID:16185943

  9. [Control study for muscle force and component of body of female patients with knee osteoarthritis].

    PubMed

    Pang, Jian; Cao, Yue-long; Shi, Yin-yu; Zhou, Ji-wei; Wang, Xiang; Shi, Ying

    2008-11-01

    To understand the information of female patients with knee osteoarthritis regarding muscle force, constitution parameter. Thirty-seven cases diagnosed as knee osteoarthritis and 37 controls were examined by MES. T-test was used to analysis two groups differences of muscle force, constitution parameter, et al. Compared between affected limbs and controls limbs in patients revealed that the lower limb muscle distribution index of the affected limbs was higher than the control limbs (P<0.05), but comparison in functional status the lower limb muscle force, muscle functional index and muscle force of unit volume of the affected limbs were lower than the control limbs (P<0.05). Compared between patients group and control group the muscle force of both lower limbs, muscle functional index and muscle force of unit volume were lower than control group (P<0.001). The utility muscle force of lower limbs of female patients with knee osteoarthritis is weaker than healthy female. Muscle function disorder instead of muscle atrophy is the key cause of the weakness.

  10. Comparison of supervised MRI segmentation methods for tumor volume determination during therapy.

    PubMed

    Vaidyanathan, M; Clarke, L P; Velthuizen, R P; Phuphanich, S; Bensaid, A M; Hall, L O; Bezdek, J C; Greenberg, H; Trotti, A; Silbiger, M

    1995-01-01

    Two different multispectral pattern recognition methods are used to segment magnetic resonance images (MRI) of the brain for quantitative estimation of tumor volume and volume changes with therapy. A supervised k-nearest neighbor (kNN) rule and a semi-supervised fuzzy c-means (SFCM) method are used to segment MRI slice data. Tumor volumes as determined by the kNN and SFCM segmentation methods are compared with two reference methods, based on image grey scale, as a basis for an estimation of ground truth, namely: (a) a commonly used seed growing method that is applied to the contrast enhanced T1-weighted image, and (b) a manual segmentation method using a custom-designed graphical user interface applied to the same raw image (T1-weighted) dataset. Emphasis is placed on measurement of intra and inter observer reproducibility using the proposed methods. Intra- and interobserver variation for the kNN method was 9% and 5%, respectively. The results for the SFCM method was a little better at 6% and 4%, respectively. For the seed growing method, the intra-observer variation was 6% and the interobserver variation was 17%, significantly larger when compared with the multispectral methods. The absolute tumor volume determined by the multispectral segmentation methods was consistently smaller than that observed for the reference methods. The results of this study are found to be very patient case-dependent. The results for SFCM suggest that it should be useful for relative measurements of tumor volume during therapy, but further studies are required. This work demonstrates the need for minimally supervised or unsupervised methods for tumor volume measurements.

  11. Comparison of temporalis fascia muscle and full-thickness cartilage grafts in type 1 pediatric tympanoplasties.

    PubMed

    Yegin, Yakup; Çelik, Mustafa; Koç, Arzu Karaman; Küfeciler, Levent; Elbistanlı, Mustafa Suphi; Kayhan, Fatma Tülin

    Various graft materials have been used to close tympanic membrane perforations. In the literature, there are few studies in pediatric populations comparing different graft materials. To our knowledge, there is no reported study that measured the thickness of the tragal cartilage in pediatric tympanoplasties. The tragal cartilage is not of uniform thickness in every patient. To compare anatomical and functional outcomes of temporalis fascia muscle and full-thickness tragal cartilage in type 1 pediatric tympanoplasties. In total, 78 patients (38 males, 40 females; average age 10.02±1.98 years; range, 7-18 years) who underwent type 1 tympanoplasties in our clinic were included. Demographics, anatomical, and functional outcomes were collected. Temporalis fascia muscle and tragal cartilage were used as graft materials. Tragal cartilage was used without thinning, and the thickness of tragal cartilage was measured using a micrometer. Anatomical and functional outcomes of cartilage and fascia were compared. Audiometric results comparing the cartilage and fascia groups were conducted at 6 months, and we continued to follow the patients to 1 year after surgery. An intact graft and an air-bone gap≤20dB were regarded as a surgical success. Results with a p-value<0.05 were considered statistically significant. The graft success rate was 92.1% for the cartilage group compared with 65.0% for the temporal fascia group. In the fascia group, the preoperative air-bone gap was 33.68±11.44 dB and postoperative air-bone gap was 24.25±12.68dB. In the cartilage group, the preoperative air-bone gap was 35.68±12.94dB and postoperative air-bone gap was 26.11±12.87dB. The anatomical success rate in the cartilage group was significantly better than that for the fascia group (p<0.01). There was no statistically significant difference in functional outcomes between the fascia and cartilage groups (p>0.05). The average thickness of tragal cartilage in the pediatric population was 0.693±0

  12. A comparison of two stretching programs for hamstring muscles: A randomized controlled assessor-blinded study.

    PubMed

    Demoulin, Christophe; Wolfs, Sébastien; Chevalier, Madeline; Granado, Caroline; Grosdent, Stéphanie; Depas, Yannick; Roussel, Nathalie; Hage, Renaud; Vanderthommen, Marc

    2016-01-01

    Most parameters regarding hamstring flexibility training programs have been investigated; however, the joint (i.e. hip or knee) on which the stretching should preferentially be focused needs to be further explored. This randomized controlled assessor-blinded study aimed to investigate the influence of this parameter. We randomly assigned 111 asymptomatic participants with tight hamstring muscles in three groups: a control group and two groups following a different home-based 8-week (five 10-minute sessions per week) hamstring stretching program (i.e. stretching performed by flexing the hip while keeping the knee extended [SH] or by first flexing the hip with a flexed knee and then extending the knee [SK]). Range of motion (ROM) of hip flexion and knee extension were measured before and after the stretching program by means of the straight leg raising test and the passive knee extension angle test, respectively. Eighty-nine participants completed the study. A significant increase in ROM was observed at post-test. Analyses showed significant group-by-time interactions for changes regarding all outcomes. Whereas the increase in hip flexion and knee extension ROM was higher in the stretching groups than in the CG (especially for the SH group p < 0.05), no differences between the two stretching groups were observed (p > 0.05). In conclusion, the fact that both stretching programs resulted in similar results suggests no influence of the joint at which the stretching is focused upon, as assessed by the straight leg raising and knee extension angle tests.

  13. Intrinsic hand muscle function, part 2: kinematic comparison of 2 reconstructive procedures.

    PubMed

    Muzykewicz, David A; Arnet, Ursina; Lieber, Richard L; Fridén, Jan

    2013-11-01

    Reconstruction of grasp is a high priority for tetraplegic patients. Restoration of finger flexion by surgical