Thigh Muscle Volume Research Articles

Strength training induces muscle hypertrophy and functional gains in black prostate cancer patients despite androgen deprivation therapy.

Androgen deprivation therapy (ADT) for prostate cancer (PCa) is associated with weakness, fatigue, sarcopenia, and reduced quality of life (QoL). Black men have a higher incidence and mortality from PCa than Caucasians. We hypothesized that despite ADT, strength training (ST) would increase muscle power and size, thereby improving body composition, physical function, fatigue levels, and QoL in older black men with PCa. Muscle mass, power, strength, endurance, physical function, fatigue perception, and QoL were measured in 17 black men with PCa on ADT before and after 12 weeks of ST. Within-group differences were determined using t tests and regression models. ST significantly increased total body muscle mass (2.7%), thigh muscle volume (6.4%), power (17%), and strength (28%). There were significant increases in functional performance (20%), muscle endurance (110%), and QoL scores (7%) and decreases in fatigue perception (38%). Improved muscle function was associated with higher functional performance (R (2) = 0.54) and lower fatigue perception (R (2) = 0.37), and both were associated with improved QoL (R (2) = 0.45), whereas fatigue perception tended to be associated with muscle endurance (R (2) = 0.37). ST elicits muscle hypertrophy even in the absence of testosterone and is effective in counteracting the adverse functional consequences of ADT in older black men with PCa. These improvements are associated with reduced fatigue perception, enhanced physical performance, and improved QoL. Thus, ST may be a safe and well-tolerated therapy to prevent the loss of muscle mass, strength, and power commonly observed during ADT.

D.P.20 CT volumetry demonstrates muscle volume decrement in GNE myopathy

GNE myopathy, alternatively called distal myopathy with rimmed vacuoles or hereditary inclusion body myopathy, is caused by missense mutations in GNE gene. Efficacy of sialic acid supplementation therapy is demonstrated in model mice and now phase II clinical trial is planned. However, evaluation method for muscle status, including that for muscle volume, is not well established for GNE myopathy. We previously reported the net muscle volumetry, which estimated the muscle volume of middle part of thigh. To know whether the net muscle volumetry by CT that we previously reported can demonstrate the muscle volume decrement along the disease course in GNE myopathy. Nineteen patients with GNE myopathy were studied twice with 6-month interval. CT images of fourteen 1-cm thickness slices of mid-thigh between 7cm above and below midpoint of trochanter and patella, and of twenty 5-mm thickness slices of mid-lower leg between 5cm above and below midpoint of fibula head and lateral malleolus were analyzed. Muscle density map was obtained using estimated linear-function. Obvious vessels and skin tissues were excluded manually from the density map and net muscle volume of thighs and lower legs was calculated. In the patients whose muscle volume was less than 200cm3, the decrement of muscle volume was not constant, because most muscle was replaced by fat and connective tissue. In patients whose net muscle volume was more than 200cm3, the decrement of net muscle volume of thigh and leg was 6.32%/year and 8.14 %/year, respectively. The leg edema was observed in two patients, that made us difficult to distinguish muscle from edematous tissue in manual eliminating procedure, because CT value of muscle tissue was close to that of edematous tissue. The net muscle volume decrement can be measured by CT. This method may be useful to evaluate muscle status especially in clinical trial.

Effect of divergent selection for the computer tomography measured thigh muscle volume on productive and carcass traits of growing rabbits

The objective of the study was to analyze the effects of divergent selection for computer tomography (CT) measured thigh muscle volume (VTM) on the production and slaughter performance of growing rabbits. Pannon White rabbits were selected to increase (PP) or decrease (MM) their VTM during two generations. Production and slaughter traits of their offspring (the third generation) were measured for 25 MM and 57 PP and for 24 MM and 24 PP rabbits, respectively. Selection had no effect on daily weight gain and body weight at 10 week. PP rabbits had lower feed consumption (128 vs. 138g/d, P<0.05) and better feed conversion ratio (FCR) (2.81 vs. 3.01, P<0.001) compared to the MM group. CT measured VTM (309 vs. 336cm3, P<0.05), hind part weight (439 vs. 473g, P<0.001) and meat weight of the hind legs (HLMW) (326 vs. 355g, P<0.001) were higher in the PP group, while the perirenal fat weight (PFaW) (29.4 vs. 23.8g, P<0.05) and the periscapular fat weight (SFaW) (13.0 vs. 6.05g, P<0.001) were lower than that of the MM rabbits. The ratio of the full gastrointestinal tract compared to body weight (GIP) was not higher for the MM rabbits (18.1% vs. 16.7%). Compared to the reference carcass, ratios of the perirenal fat (PFaP) (2.40% vs. 1.90%, P<0.05) and periscapular fat (SFaP) (1.07% vs. 0.49%, P<0.001) were higher in the MM group while ratios of the hind part (HPP) (36.3% vs. 38.2%, P<0.001) and hind leg meat were higher (HLMP) in the PP group (26.9% vs. 28.7%, P<0.001). It was thus shown that CT aided selection can efficiently increase the thigh muscle volume. At the same time the volume of fat depots decreased while FCR also improved.

Safety of the antimyostatin monoclonal antibody LY2495655 in healthy subjects and patients with advanced cancer.

2516 Background: Skeletal muscle wasting (cachexia) is a prevalent and not readily managed condition in advanced cancer patients. LY2495655 is a humanized monoclonal antibody to myostatin, which has demonstrated positive effects on cachexia measures in animal models. We present phase I trial data on use of LY2495655 in healthy volunteers (Study 1) and interim data from an ongoing phase I study in patients with advanced cancer (Study 2). Methods: Study 1 was a randomized, placebo-controlled, blinded, single-dose, parallel, dose-escalation study evaluating the safety and tolerability of IV or SC LY2495655 (0.7 mg-700 mg). Study 2 is an ongoing nonrandomized, open-label study evaluating the safety and pharmacokinetics (PKs) of LY2495655 in patients with advanced cancer not receiving chemotherapy. Dose cohorts (2 mg-700 mg, ≥3 patients per cohort) were to be treated until the maximum tolerated dose (MTD) was met, or the highest dose (700 mg) cohort was completed. Final locked data from Study 1 and interim data from the dose escalation phase of Study 2 were used in the analyses. Results: In Study 1, 64 healthy volunteers were enrolled (48 LY2495655, 16 placebo). In Study 2, 22 patients had received treatment with LY2495655 at the time of the analysis. In both studies, all doses of LY2495655 were well tolerated (no DLTs were observed and MTD was not reached), and nonlinear PKs were observed (most evident in lower dose levels). In Study 1, thigh muscle volume generally increased with LY2495655. In Study 2, increased muscle volume was observed only at 21-mg and 70-mg doses. Consistent increases in hand grip strength and improvements in functional tests were observed at doses ≥21 mg. Conclusions: There were no unusual safety concerns in healthy subjects or cancer patients. PK results were consistent between the 2 studies. Increases in muscle volume were observed in both studies, with concomitant improvement in functional measures. However, there is no clear trend in dose-dependent efficacy, possibly due to extremely small sample sizes and patient heterogeneity. Enrollment in Study 2 continues with dose expansion cohorts. A Phase 2 study is ongoing in pancreatic cancer patients.

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

BackgroundPreclinical 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 FindingsCommunity-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/SignificanceData 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-scale studies are needed to corroborate these preliminary findings and determine if down-regulation of apoptotic signaling in skeletal myocytes will provide improvements in the muscle mass and functional status of older persons.

Genetic parameters for litter weight, average daily gain and thigh muscle volume measured by in vivo Computer Tomography technique in Pannon White rabbits

Genetic parameters were estimated in Pannon White rabbits for average daily gain (ADG, between the ages of 5 and 10weeks), thigh muscle volume (TMV, determined by Computer Tomography-scan) and litter weight at day 21 (recorded separately for each parity within the first four parities, LW21). LW21 of each parity of the first four parities were considered as separate traits, and all traits were analysed jointly using a six-trait animal model. REML procedure was applied using PEST for data coding and VCE software for estimating variance components. The heritability estimates for LW21 were moderately low and ranged between 0.10±0.02 and 0.17±0.02. Higher heritability estimates were recorded for TMV (0.20±0.02) and for ADG (0.21±0.01). The random common litter effects were low for LW21 (ranged between 0.04±0.01 and 0.13±0.04) and TMV (0.14±0.02) but these effects were moderate for ADG (0.18±0.01). An unfavourable genetic correlation was found between LW21 and TMV especially for the 3rd (−0.53±0.09) and 4th (−0.70±0.09) parities.

Muscle Changes Following Cycling and/or Electrical Stimulation in Pediatric Spinal Cord Injury

Johnston TE, Modlesky CM, Betz RR, Lauer RT. Muscle changes following cycling and/or electrical stimulation in pediatric spinal cord injury. Objective To determine the effect of cycling, electrical stimulation, or both, on thigh muscle volume and stimulated muscle strength in children with spinal cord injury (SCI). Design Randomized controlled trial. Setting Children's hospital specializing in pediatric SCI. Participants Children (N=30; ages, 5–13y) with chronic SCI. Interventions Children were randomly assigned to 1 of 3 interventions: functional electrical stimulation cycling (FESC), passive cycling (PC), and noncycling, electrically stimulated exercise (ES). Each group exercised for 1 hour, 3 times per week for 6 months at home. Main Outcome Measures Preintervention and postintervention, children underwent magnetic resonance imaging to assess muscle volume, and electrically stimulated isometric muscle strength testing with the use of a computerized dynamometer. Data were analyzed via analyses of covariance (ANCOVA) with baseline measures as covariates. Within-group changes were assessed via paired t tests. Results All 30 children completed the training. Muscle volume data were complete for 24 children (8 FESC, 8 PC, 8 ES) and stimulated strength data for 27 children (9 per group). Per ANCOVA, there were differences between groups ( P<.05) for quadriceps muscle volume and stimulated strength, with the ES group having greater changes in volume and the FESC group having greater changes in strength. Within-group analyses showed increased quadriceps volume and strength for the FESC group and increased quadriceps volume for the ES group. Conclusions Children receiving either electrically stimulated exercise experienced changes in muscle size, stimulated strength, or both. These changes may decrease their risk of cardiovascular disease, insulin resistance, glucose intolerance, and type 2 diabetes. Clinical Trials Registration Number NCT00245726.

Component characteristics of thigh muscle volume in young and older healthy men

The purpose of this study was to compare the component characteristics of thigh muscle volume in Japanese young and older men. The subjects in both young (YM, n = 15) and older (OM, n = 13) men were physically active (performed aerobic-type exercise 1-3 times per week), but none of the subjects had regularly participated in resistance training for a minimum of 3 years prior to the study. Contiguous transverse magnetic resonance imaging (1.5-T scanner) images were obtained from the thigh, and total and individual (quadriceps, hamstrings and adductors) muscle volumes were calculated by multiplying the muscle cross-sectional area (CSA) by slice thickness and the total number of slices. Muscle length and average muscle CSA (muscle volume divided by muscle length) were determined for each muscle. Maximum voluntary isometric (MVC) knee extension and flexion strength were measured, and muscle quality was defined as MVC per unit average muscle CSA (MVC/CSA). Quadriceps muscle volume and average CSA were, respectively, 20% and 16% lower (P < 0.05) in the OM than in the YM, while hamstrings and adductors muscle volumes and average CSA were similar in both groups. Knee extension and flexion MVC were lower (P < 0.05) in the OM than in the YM. Knee extensor MVC/CSA was similar in the two groups, while knee flexor MVC/CSA was lower (P < 0.05) in the OM than in the YM. Our results suggest that age-related thigh muscle volume loss is muscle specific, in that greater quadriceps muscle loss was found in the older group.

Effects of 8-Week in-Season Upper and Lower Limb Heavy Resistance Training on The Peak Power, Throwing Velocity, and Sprint Performance of Elite Male Handball Players

The aims of this study were to test the potential of in-season heavy upper and lower limb strength training to enhance peak power output (Wpeak), vertical jump, and handball related field performance in elite male handball players who were apparently already well trained, and to assess any adverse effects on sprint velocity. Twenty-four competitors were divided randomly between a heavy resistance (HR) group (age 20 ± 0.7 years) and a control group (C; age 20 ± 0.1 years). Resistance training sessions were performed twice a week for 8 weeks. Performance was assessed before and after conditioning. Peak power (W(peak)) was determined by cycle ergometer; vertical squat jump (SJ) and countermovement jump (CMJ); video analyses assessed velocities during the first step (V(1S)), the first 5 m (V(5m)), and between 25 and 30 m (V(peak)) of a 30-m sprint. Upper limb bench press and pull-over exercises and lower limb back half squats were performed to 1-repetition maximum (1RM). Upper limb, leg, and thigh muscle volumes and mean thigh cross-sectional area (CSA) were assessed by anthropometry. W(peak) (W) for both limbs (p < 0.001), vertical jump height (p < 0.01 for both SJ and CMJ), 1RM (p < 0.001 for both upper and lower limbs) and sprint velocities (p < 0.01 for V(1S) and V(5m); p < 0.001 for V(peak)) improved in the HR group. Upper body, leg, and thigh muscle volumes and thigh CSA also increased significantly after strength training. We conclude that in-season biweekly heavy back half-squat, pull-over, and bench-press exercises can be commended to elite male handball players as improving many measures of handball-related performance without adverse effects upon speed of movement.

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

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.

Growth hormone treatment for two years is safe and effective in adults with Prader-Willi syndrome

ObjectivePrader-Willi syndrome (PWS) shares similarities with the growth hormone (GH) deficiency syndrome in regards to reduced lean body mass and increased fat mass and several short-term trials with GH treatment have demonstrated beneficial effects on body composition. The aim of the present study was to evaluate the effects and safety of two years of GH therapy in adults with PWS. DesignForty-three adults (24 women) with genetically verified PWS were included. Blood samples, body composition as measured by computed tomography (CT) and dual-energy x-ray absorptiometry (DXA) were performed at baseline and during two years of continued GH treatment. ResultsThirty-nine patients completed treatment for two years. The GH dosage averaged 0.61mg/day (range 0.2–1.6). Based upon CT, body composition improved at two years; thigh muscle volume increased 6.7mL (3.7 to 9.7; P<0.001) whereas abdominal subcutaneous fat volume decreased by 53.3mL (13.8 to 92.9; P=0.01). By DXA, lean body mass improved 2.8kg (1.9 to 3.6; P<0.001), whereas fat mass decreased by 3.0kg (1.1 to 4.8; P=0.003). Lung function as evaluated by peak expiratory flow increased 12% (p<0.001) — indicating improved muscle function. Adverse effects were few. Fifteen out of 39 patients had diabetes (DM; n=4) or impaired glucose tolerance (IGT; n=11) prior to GH treatment. Among the 11 patients with IGT, three reverted to normal glucose tolerance, while three progressed to overt DM at two years of GH treatment. ConclusionThe known beneficial effects of GH treatment upon body composition in PWS are maintained during two years continuous treatment. With appropriate control, GH is a safe treatment option in adults with PWS.

Thigh Muscle Volume Measured by Magnetic Resonance Imaging Is Stable Over a 6-Month Interval in Spinal Muscular Atrophy

Changes in thigh muscle volume over 6 months were assessed using magnetic resonance imaging in 11 subjects aged 6 to 47 years with spinal muscular atrophy (4 type 2 and 7 type 3; 4 ambulatory and 3 nonambulatory). Muscle volume with normal and abnormal signal was measured using blinded, semiautomated analysis of reconstructed data. Volumes at baseline and 6 months were correlated with clinical function at each epoch. There was minimal increase in normal (0.3 ± 1.4 mL/cm) and total (0.1 ± 1.3 mL/cm) muscle. Muscle volume correlated closely with clinical function. Minimal interval change in muscle volume is consistent with the established clinical history of minimal disease progression over intervals shorter than 1 year. Relative constancy of muscle volume estimation and correlation with established functional measures suggest a role for segmental magnetic resonance imaging as a biomarker of treatment effect in future therapeutic trials.

Effect of Strength Training on Muscle Hypertrophy and Body Composition during Androgen Deprivation Therapy

Androgen deprivation therapy (ADT) is effective for slowing tumor growth in prostate cancer (PCa) patients but results in numerous adverse side effects. While strength training (ST) has previously been demonstrated to be safe and effective in these patients, it remains unclear whether muscle hypertrophy and body composition alterations occur in the absence of testosterone. Thus, we sought to determine the effects of ST on regional and total body composition in PCa patients undergoing ADT. Total body fat free mass (FFM) and fat mass, thigh muscle volume (MV), subcutaneous (SCF), and intermuscular fat (IMF) were assessed in 16 PCa patients (68 ± 2 yrs) before and after 12 wks of ST using dual energy x-ray absorptiometry and computed tomography. The ST program resulted in significant gains in MV (R leg, 6.6 ± 0.8%; L leg 6.7 ± 0.9%, both P < 0.001), FFM (2.7 ± 0.4%, P < 0.001), and body weight (1.7 ± 0.4%, P = 0.001). There was no change in SCF (R leg, 1.0 ± 1.4%; L leg 0.8 ± 1.3%, both P = 0.48), IMF (R leg, 1.3 ± 3.2%; L leg 2.8 ± 3.3%, P = 0.81 and 0.51), or total body fat mass with ST (−0.4 ± 1.2%, P=0.85), though % fat declined significantly (−2.0 ± 0.9%, P = 0.023). Despite ablation of testosterone, ST can induce muscle hypertrophy in PCa patients on ADT, but has no effect on total or regional fat mass.

Yo-Yo Intermittent Recovery Level 2 Test Performance and Leg Muscle Growth in a Six-month Period among Pubescent Soccer Players at Different Stages of Maturity

This study examined the relationships between longitudinal changes in data obtained in the Yo-Yo intermittent recovery level 2 test (Yo-Yo IR2), maximal oxygen consumption (VO2max) and leg muscle size and function in pubescent soccer players. Forty-four soccer players with a mean age of 12.8±0.2 years participated, and were classified into three maturational groups (Late, Average and Early) according to their peak height velocity age. The Yo-Yo IR2 and five-jump tests along with measurement of VO2max and thigh muscle volume were conducted on two occasions 6 months apart. Performances in the Yo-Yo IR2 for the Late, Average and Early groups were 311±61, 371±88 and 411±72 meters at the first measurement, and 389±73, 509±117 and 621±69 meters 6 months later. Consequently, two-way repeated-measures ANOVA revealed a significant interaction whereby the improvement in Yo-Yo IR2 performance was larger in the Early group (51.3%) than in the Late group (24.8%). Greater increases of thigh muscle volume and the result of the five-jump test were found in the Early group, and these were correlated significantly (r=0.52, p<0.05; r=0.39, p<0.05) with improvement of Yo-Yo IR2 performance. In contrast, there was no relationship (r=−0.02, n.s.) between the increments of VO2max and Yo-Yo IR2 performance. These results suggest that performance in the Yo-Yo IR2 is affected by maturity to a great extent, early-maturing players having an advantage in terms of leg muscle development.

Effect of exercise intervention on thigh muscle volume and anatomical cross‐sectional areas—Quantitative assessment using MRI

The objective of this study was to evaluate the location-specific magnitudes of an exercise intervention on thigh muscle volume and anatomical cross-sectional area, using MRI. Forty one untrained women participated in strength, endurance, or autogenic training for 12 weeks. Axial MR images of the thigh were acquired before and after the intervention, using a T1-weighted turbo-spin-echo sequence (10 mm sections, 0.78 mm in-plane resolution). The extensor, flexor, adductor, and sartorius muscles were segmented between the femoral neck and the rectus femoris tendon. Muscle volumes were determined, and anatomical cross-sectional areas were derived from 3D reconstructions at 10% (proximal-to-distal) intervals. With strength training, the volume of the extensors (+3.1%), flexors (+3.5%), and adductors (+3.9%) increased significantly (P < 0.05) between baseline and follow-up, and with endurance training, the volume of the extensor (+3.7%) and sartorius (+5.1%) increased significantly (P < 0.05). No relevant or statistically significant change was observed with autogenic training. The greatest standardized response means were observed for the anatomical cross-sectional area in the proximal aspect (10-30%) of the thigh and generally exceeded those for muscle volumes. The study shows that MRI can be used to monitor location-specific effects of exercise intervention on muscle cross-sectional areas, with the proximal aspect of the thigh muscles being most responsive.

Increases in Thigh Muscle Volume and Strength by Walk Training with Leg Blood Flow Reduction in Older Participants

We examined the effects of walk training combined with leg blood flow reduction (BFR) on muscle hypertrophy as well as on peak oxygen uptake (VO₂ peak) in older individuals. Both the BFR walk training (BFR-Walk, n = 10, age; 64 ± 1 years, body mass index [BMI]; 22.5 ± 0.9 kg/m²) and control walk training (CON-Walk, n = 8, age; 68 ± 1 years, BMI; 23.2 ± 1.0 kg/m²) groups performed 20 minutes of treadmill walking at an exercise intensity of 45% of heart rate reserve, 4 days per week, for 10 weeks. The BFR-Walk group wore pressure belts (160-200 mm Hg) on both legs during training. After the training, magnetic resonance imaging-measured thigh muscle cross-sectional area (3.1%, p < .01) and muscle volume (3.7%, p < .01) as well as maximal isometric (5.9%, p < .05) and isokinetic (up to 22%, p < .01) strength increased in the BFR-Walk group, but not in the CON-Walk group. Estimated VO₂ peak during a bicycle graded exercise test increased (p < .05) and correlated with oxygen pulse in both groups. In conclusion, BFR walk training improves both muscle volume and strength in older women.

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

(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.

Muscle Volume Estimation by Magnetic Resonance Imaging in Spinal Muscular Atrophy

Thigh muscle volume was assessed using magnetic resonance imaging in 16 subjects with spinal muscular atrophy. Scans were successful for 14 of 16 subjects (1 type 1, 6 type 2, and 7 type 3) as young as 5.7 years. Muscle volume with normal and abnormal signal was measured using blinded, semiautomated analysis of reconstructed data. Results were compared with segmental lean mass estimated by dual-energy X-ray absorptiometry and correlated with clinical and electrophysiological measures of disease severity. Muscle volume was reduced with abnormal signal quality. Test-retest reliability (r = .99) and correlation with dual-energy X-ray absorptiometry (r = .91) were excellent. Type 2 subjects had lower volume (3.5 ± 1.6 vs 6.3 ± 2.8 mL/cm height; P = .06) and higher percentage of muscle with abnormal signal (68% ± 20% vs 47% ± 27%; P = .14) than type 3. Reproducibility, tolerability, and strong correlation with clinical measures make magnetic resonance imaging a candidate biomarker for clinical research.

Effects of in-Season Short-Term Plyometric Training Program on Leg Power, Jump- and Sprint Performance of Soccer Players

Our hypothesis was that the addition of an 8-week lower limb plyometric training program (hurdle and depth jumping) to normal in-season conditioning would enhance measures of competitive potential (peak power output [PP], jump force, jump height, and lower limb muscle volume) in junior soccer players. The subjects (23 men, age 19 ± 0.7 years, body mass 70.5 ± 4.7 kg, height 1.75 ± 0.06 m, body fat 14.7 ± 2.6%) were randomly assigned to a control (normal training) group (Gc; n = 11) and an experimental group (Gex, n = 12) that also performed biweekly plyometric training. A force-velocity ergometer test determined PP. Characteristics of the squat jump (SJ) and the countermovement jump (CMJ) (jump height, maximal force and velocity before take-off, and average power) were determined by force platform. Video-camera kinematic analyses over a 40-m sprint yielded running velocities for the first step (VS), the first 5 m (V5m) and between 35 and 40 m (Vmax). Leg muscle volume was estimated using a standard anthropometric kit. Gex showed gains relative to controls in PP (p < 0.01); SJ (height p < 0.01; velocity p < 0.001), CMJ (height p < 0.001; velocity p < 0.001, average power p < 0.01) and all sprint velocities (p < 0.001 for V5m and Vmax, p < 0.01 for VS). There was also a significant increase (p < 0.05) in thigh muscle volume, but leg muscle volume and mean thigh cross-sectional area remain unchanged. We conclude that biweekly plyometric training of junior soccer players (including adapted hurdle and depth jumps) improved important components of athletic performance relative to standard in-season training. Accordingly, such exercises are highly recommended as part of an annual soccer training program.

Arterial stiffness is associated with low thigh muscle mass in middle-aged to elderly men

ObjectiveSarcopenia of legs is an important cause of physical dysfunctions, frailty and dependence. Many predisposing and underlying mechanisms of sarcopenia, including age, sedentary life style, oxidative stress, insulin resistance, and low testosterone levels, are also known to be related to atherosclerosis, which is another leading cause of morbidity and mortality in elderly subjects. In this study, we investigated our hypothesis that sarcopenia and atherosclerosis are associated with each other to facilitate mutual abnormalities. MethodsStudy was performed in apparently healthy 496 middle-aged to elderly persons recruited consecutively among the visitors to the medical check-up program, Anti-Aging Doc, in a University hospital, from March 2006 to December 2007. Mid-thigh muscle cross-sectional area (CSA) was measured by computed tomography and corrected by body weight (CSA/BW). Carotid intima–media thickness (IMT) and brachial–ankle pulse wave velocity (baPWV) were measured. ResultsThigh muscle CSA/BW was significantly and negatively associated with carotid IMT and baPWV in men but not in women. After correction for other confounding parameters, baPWV was an independent risk for the presence of sarcopenia in men (odds ratio of 1m/s increase of baPWV=1.14, 95% CI=1.01–1.30, p<0.05) in addition to age, body height, low physical activity, free testosterone level. Conversely, thigh muscle CSA/BW was an independent determinant of baPWV (β=−0.15, p<0.01) in addition to age, blood pressure, triglyceride, and antihypertensive drug use in men. ConclusionsArterial stiffness is related to thigh muscle volume in men. Sarcopenia and atherosclerosis may share a common pathway and interact with each other to facilitate mutual abnormalities.