Lower Limb Muscle Volume Research Articles

The Rheumatoid Arthritis and MUScle (RAMUS) Study: Protocol for an observational single-arm study of skeletal muscle in patients with rheumatoid arthritis receiving tofacitinib.

People with rheumatoid arthritis (RA) are disproportionately affected by sarcopenia, the generalised loss of muscle strength and mass, consequently facing an increased risk of falls, functional decline and death. Currently, there are no approved pharmacological treatments for sarcopenia. RA patients who start tofacitinib (a Janus kinase inhibitor) develop small increases in serum creatinine that are not explained by renal function changes and could reflect sarcopenia improvement. The RAMUS Study is a proof of concept, single-arm observational study in which patients with RA who commence tofacitinib according to routine care will be offered participation according to eligibility criteria. Participants will undergo lower limb quantitative magnetic resonance imaging, whole-body dual energy x-ray absorptiometry, joint examination, muscle function testing and blood tests at three time points: prior to starting tofacitinib and 1 and 6 months afterwards. Muscle biopsy will be performed before and 6 months after starting tofacitinib. The primary outcome will be lower limb muscle volume changes following treatment initiation. The RAMUS Study will investigate whether muscle health improves following tofacitinib treatment for RA. Identifying a potential pharmacological treatment for sarcopenia could have important implications for individuals with RA and for older people in general. ISRCTN registry ID: 13364395.

The relationship between lower limb muscle volume and peak vertical jump power in children

BACKGROUND: Vertical jump is an index representing leg power. It is important to determine factors that influence the vertical jump to help athletes improve their leg power. OBJECTIVE: This study aimed to determine the relationship between lower limbs muscle volume and peak vertical jump (VJ) power in children for both sexes. METHODS: Fourty children healthy boys (n= 20) and girls (n= 20) aged 10 to 12 years old, randomly performed three VJ modalities: squat jump (SJ), counter movement jump without (CMJ) and with arm swings (CMJarms). Lower limbs muscle volume (MV) estimated using a standard anthropometric method. Peak power (PP) calculated by Sayers equation. RESULTS: significant correlations between MV and Peak vertical jump power showed for both sexes. Likewise, significant correlations were found between MV and body mass for boys (r= 0.66; p= 0.001) and for girls (r= 0.59; p= 0.006). CONCLUSIONS: The correlation observed between peak vertical jump power and MV in both sexes can be considered as estimation tool of the lower limbs muscle power. Lower limb’s muscle volume are determining factor in muscle power for both sexes.

Effects of squat training with different depths on lower limb muscle volumes.

The purpose of this study was to compare the effects of squat training with different depths on lower limb muscle volumes. Seventeen males were randomly assigned to a full squat training group (FST, n = 8) or half squat training group (HST, n = 9). They completed 10weeks (2days per week) of squat training. The muscle volumes (by magnetic resonance imaging) of the knee extensor, hamstring, adductor, and gluteus maximus muscles and the one repetition maximum (1RM) of full and half squats were measured before and after training. The relative increase in 1RM of full squat was significantly greater in FST (31.8 ± 14.9%) than in HST (11.3 ± 8.6%) (p = 0.003), whereas there was no difference in the relative increase in 1RM of half squat between FST (24.2 ± 7.1%) and HST (32.0 ± 12.1%) (p = 0.132). The volumes of knee extensor muscles significantly increased by 4.9 ± 2.6% in FST (p < 0.001) and 4.6 ± 3.1% in HST (p = 0.003), whereas that of rectus femoris and hamstring muscles did not change in either group. The volumes of adductor and gluteus maximus muscles significantly increased in FST (6.2 ± 2.6% and 6.7 ± 3.5%) and HST (2.7 ± 3.1% and 2.2 ± 2.6%). In addition, relative increases in adductor (p = 0.026) and gluteus maximus (p = 0.008) muscle volumes were significantly greater in FST than in HST. The results suggest that full squat training is more effective for developing the lower limb muscles excluding the rectus femoris and hamstring muscles.

Playing Level and Position Differences in Body Characteristics and Physical Fitness Performance Among Male Team Handball Players.

The primary aim of the study was to examine the anthropometric characteristics, as well as the physical performance of professional handball players classified by playing position and competition level. Twenty male players (age: 20.4 ± 0.88 years) from the first handball league and 18 male players (age: 21.3 ± 1.61 years) from the second handball league were categorized as backs (8/8), pivots (5/4), and wings (7/6). The following variables were measured in both groups: peak power; vertical squat jump (SJ), and countermovement jump (CMJ); sprint times over 15 and 30 m; handball throwing velocity during the jump shot (JS); and 3 steps shot (T3 step); upper and lower limb muscle volumes; Yo-Yo Intermittent Recovery Test. Anthropometric data revealed significantly (p = 0.003, = 0.248) less muscle volume for second league players (3.13 ± 0.29 l) than for first league (3.71 ± 0.82 l). The cross-sectional area for the first league players was also larger (p = 0.010, = 0.192). Regarding performance parameters, we found significant (p < 0.05 and > 0.20) league differences in five of 15 (33%) performance parameters: running throw ( = 0.285), SJ power ( = 0.670), SJ velocity ( = 0.900), peak upper limb power ( = 0.231) and Yo-Yo-IR 1 ( = 0.348). The second league players showed higher SJ velocity than the first league players ( = 0.900). In contrast, we detected a greater difference in SJ power ( = 0.670) but in favor of the first league players. Pivots were the players with the highest throwing velocity and wings were the fastest (15, 30 m sprint), strongest (countermovement jump), and most enduring (Yo-Yo-IR 1) athletes. Backs showed consistently the lowest level throwing velocity and sprint performance (exception: second league). The anthropometric differences between playing levels and playing positions may indicate the advantageous characteristics that the respective position demands, whereas the playing position differences in physical fitness characteristics may indicate training specificity issues that must be addressed cautiously.

744-P: Associated Factors with Limb Muscle Volume Distribution in Type 2 Diabetes

Background: Type 2 diabetes (T2DM) and sarcopenia have a reciprocal association and could cause a vicious cycle. Resistance training has been proposed to prevent the cycle. It has been postulated that the associated factors with upper limb muscle volume (MV) and lower limb MV were different in T2DM. For efficient resistance training programs, it is needed to understand the factors affect to the imbalance between upper and lower limb MV in T2DM. Aim: We aimed to clarify the clinical associated factors for lower-to-upper limb MV ratio in T2DM. Method: We assessed in 505 patients with T2DM visited at Osaka City Hospital (male: n=303, mean ages 63.5±13.1, female: n=202, mean ages 64.3±13.4). MV in upper and lower limb were measured by a bioelectrical impedance analysis. The association between lower-to-upper limb MV ratio and clinical parameters were investigated. Results: Mean body mass index (BMI) were 26.2±5.0kg/m2 in male and 26.8±5.5kg/m2 in female. Mean lower-to-upper limb MV ratio were significantly lower in male than female (male: 2.9±0.3 vs. female: 3.2±0.5, p&amp;lt;0.001). Mean lower-to-upper limb MV ratio in male was correlated with age, BMI, visceral fat area (VFA), estimated GFR (eGFR), hemoglobin (Hb), C reactive protein (CRP). In female, that was correlated with age, BMI, VFA, Hb, CRP and HbA1c. Multiple regression analysis showed that BMI and Hb were the negative independent factors, and VFA and systolic blood pressure were the positive independent factors for lower-to-upper limb MV ratio in male T2DM (R2=0.262, p&amp;lt;0.001). In female T2DM, BMI was the negative independent factor for lower-to-upper limb MV ratio. Notably, VFA exhibit positive correlation to lower-to-upper limb MV ratio in male obese T2DM (r=-0.252, p=0.001), but VFA negatively correlated in male non-obese T2DM (r=0.244, p=0.006). Conclusions: Gender, blood pressure, Hb and especially visceral obesity, were the important relevant factors for imbalance between upper and lower limb muscle volume in type 2 diabetes. Disclosure K. Motoyama: None. S. Tazoe: None. A. Tamai: None. T. Sakura: None. M. Ohara: None. Y. Yakushiji: None. M. Fukumoto: None. M. Hosoi: Speaker's Bureau; Self; Eli Lilly and Company.

The effects of unilateral and bilateral eccentric overload training on hypertrophy, muscle power and COD performance, and its determinants, in team sport players.

The study aimed to compare the chronic eccentric-overload training effects of unilateral (lateral lunge) vs bilateral (half-squat) using an inertial device, on hypertrophy and physical performance. Twenty-seven young team sports male players performed a 4 sets of 7 repetitions of inertial eccentric overload training, biweekly for 6 weeks, distributed in unilateral lunge group (UG: age: 22.8 ± 2.9 years; body mass: 75.3 ± 8.8 kg; height: 177.3 ± 3.7 cm) and bilateral squat group (BG: age: 22.6 ± 2.7 years; body mass: 79.5 ± 12.8 kg; height: 164.2 ± 7 cm). Lower limb muscle volume, counter movement jump (CMJ), power with both (POWER), dominant (POWERd) and no-dominant leg (POWERnd), change of direction turn of 90° with dominant (COD90d) and no-dominant leg (COD90nd) and 180° (COD180d and COD180nd), and 10m sprint time (T-10m) were measured pre and post-intervention. The UG obtained an increase of adductor major (+11.1%) and vastus medialis (+12.6%) higher than BG. The BG obtained an increase of vastus lateralis (+9.9%) and lateral gastrocnemius (+9.1%) higher than UG. Both groups improved CMJ, POWER, POWERd, POWERnd, COD90 and DEC-COD90, without changes in T-10m. The UG decrease DEC-COD90nd (-21.1%) and BG increase POWER (+38.6%) substantially more than the other group. Six-weeks of unilateral / bilateral EO training induce substantial improvements in lower limbs muscle volume and functional performance, although unilateral training seems to be more effective in improving COD90 performance.

The relationship between lower limb muscle volume and body mass in ambulant individuals with bilateral cerebral palsy

BackgroundIndividuals with cerebral palsy have smaller muscle volumes normalised to body mass than their typically developing peers. The aim of this study is to investigate the relationship between lower limb muscle volume and body mass in young people with bilateral cerebral palsy and their typically developing peers.MethodsTwenty-five participants with bilateral cerebral palsy (aged 14.7±3.0 years, GMFCS level I-III) and 25 of their typically developing peers (aged 16.8±3.3 years) took part in this study. None of the participants had undergone orthopaedic surgery, botulinum toxin injections, or serial casting in the previous year. All participants underwent magnetic resonance imaging of both lower limbs. Nine major muscles of each lower limb were individually manually segmented and the muscle volumes calculated.ResultsBody mass and total lower limb muscle volume were significantly linearly related in both the cerebral palsy (R2 = 0.75, p<0.001) and typically developing (R2 = 0.77, p<0.001) groups. The slope of the relationship between muscle volume and body mass was significantly shallower in the cerebral palsy group compared to the typically developing group (p=0.007).ConclusionsThis cross-sectional study suggests that the increase in size of lower limb muscles relative to body mass is reduced in adolescents and young adults with cerebral palsy. Longitudinal studies are required to further investigate altered muscle growth trajectories in this group and their impact on long-term mobility.

Pediatric Aerobic Fitness and Trainability.

Three papers which between them raise controversial issues, apply laboratory measures to sport performance, and expose gaps in knowledge were selected for commentary. The first paper (Sports Med. 2016;46:1451-1460) reviews the literature on peak V̇O2 in relation to body size and recommends that peak V̇O2 in youth is best expressed via allometric scaling of lean body mass. The second paper (Pediatr Exerc Sci. 2016;28:456-465) reports that maturity status has no effect on peak V̇O2, respiratory compensation point, or ventilatory threshold in youth soccer players once data have been allometrically normalized by lower limb muscle volume. It concludes that in future this technique should be used to compare the aerobic fitness of youth soccer players. The third paper (Eur J Appl Physiol. 2016;116:1781-1794) demonstrates that V̇O2 kinetics determined in a laboratory is related to measures associated with soccer match play and might distinguish superior performance within a group of highly trained youth players. The commentary stresses the importance of experimental rigor, emphasizes the need for appropriate scaling of physiological variables, challenges spurious correlations with health-related variables, endorses the use of a range of aerobic fitness measures, welcomes the application of laboratory data to sport performance, and identifies areas for future research.

Maturity Status Does Not Exert Effects on Aerobic Fitness in Soccer Players After Appropriate Normalization for Body Size.

The present study investigated the effects of pubertal status on peak oxygen uptake (VO2peak), respiratory compensation point (RCP), and ventilatory threshold (VT) in young soccer players using different body size descriptors. Seventy-nine soccer players (14 prepubescent, 38 pubescent and 27 postpubescent) participated in this study. A maximal exercise test was performed to determine the VO2peak, RCP, and VT. Ultrasonography was used to measure lower limb muscle volume (LLMV). LLMV (mL-b) was rated as the most effective body size descriptor to normalize VO2peak (mLO2·mL-0.43·min-1), RCP (mLO2·mL-0.48·min-1), and VT (mLO2·mL- 0.40·min-1). The values of VO2peak, RCP, and VT relative to allometric exponents derived by LLMV were similar among groups (p > .05; 0.025 < η2 < 0.059) when the effect of chronological age was controlled. Allometric VO2peak, RCP, and VT values were: 100.1 ± 7.9, 107.5 ± 9.6, and 108.0 ± 10.3 mLO2.mL-0.43·min-1; 51.8 ± 5.3, 54.8 ± 4.7, and 57.3 ± 5.8 mLO2·mL-0.48·min-1; and 75.7 ± 7.1, 79.4 ± 7.0, and 80.9 ± 8.3 mLO2·mL- 0.40·min-1 for prepubertal, pubertal, and postpubertal groups, respectively. Maturity status showed no positive effect on VO2peak, RCP, and VT when the data were properly normalized by LLMV in young soccer players. Allometric normalization using muscle volume as a body size descriptor should be used to compare aerobic fitness between soccer players heterogeneous in chronological age, maturity status, and body size.

Effects of In-Season Short-term Plyometric Training Program on Sprint and Jump Performance of Young Male Track Athletes.

We studied the effect of supplementing normal in-season training by a 10-week lower limb plyometric training program (hurdle and depth jumping), examining measures of competitive potential (peak power output [PP], sprint running velocity, squat jump [SJ], countermovement jump [CMJ], drop jump [DJ], and lower limb muscle volume). The subjects (27 male track athletes, aged 11.9 ± 1.0 years; body mass: 39.1 ± 6.1 kg; height: 1.56 ± 0.02 m; body fat: 12.8 ± 4.4%) were randomly assigned between a control (normal training) group (C; n = 13) and an experimental group (E; n = 14) who also performed plyometric training 3 times per week. A force-velocity ergometer test determined PP and SJ, and an Optojump apparatus evaluated CMJ height and DJ (height and power). A multiple-5-bound test assessed horizontal jumping, and video-camera analyses over a 40-m sprint yielded velocities for the first step (VS), the first 5 m (V5m), and between 35 and 40 m (Vmax). Leg muscle volume was estimated anthropometrically. Experimental group showed gains relative to C in SJ height (p < 0.001); CMJ height (p < 0.01); DJ height and power relative to body mass (p < 0.01 for both); and all sprint velocities (p < 0.01 for VS and V(5m, p) ≤ 0.05 for Vmax). There was also a significant increase (p < 0.01) in thigh muscle volume, but leg muscle volume, thigh cross-sectional area, and PP remained unchanged. We conclude that adding plyometric training improved important components of athletic performance relative to standard in-season training in young runners.

Allometric Scaling Is The Best Method For Normalizing Maximal Oxygen Uptake In Young Soccer Players

Maximum oxygen uptake (VO2max) has been considered an important marker of health and sports performance. Traditionally VO2max is normalized by body mass (mL.kg-1.min-1), however this approach leads an overestimation of the performance in lighter individuals and an underestimation in those heavier. Determine what method is the most appropriate to normalize VO2max is important to allow comparisons between individuals with different body size. PURPOSE: To investigate the best method of normalization for VO2max in young athletes heterogeneous in body size using separate scaling variables and allometric modeling. METHODS: Seventy-nine young soccer players (age = 15.3±1.5 years, body mass = 68±10 kg, height = 175±8 cm and VO2max = 4136±552 mL.min-1) participated in this study. Scaling variables were body mass, height, body mass index (BMI), interaction between body mass height, body surface area (BSA), rectus femoris cross-section area (CSA), thigh and leg muscle thickness (MT) and muscle volumes (MV) (thigh, leg, and lower limbs). Allometric model was adopted to examine the relationship between body size descriptor and VO2max (Y = aXbε). CSA, MT and MV were measured using ultrasonography and VO2max using a metabolic cart. The variables with a very large correlation with VO2max were considered for normalization. RESULTS: CSA, BMI and thigh and leg MT and MV were discarded as a moderate to large correlation with VO2max mL.min-1 (0.3 < r < 0.7) was found. Body mass, height, BSA, interaction body mass height, and lower limb MV showed a very large correlation (r > 0.7) with VO2max mL.min-1. After normalization by body mass (mL.kg-1.min-1), height (mL.m-1.min-1), BSA (mL.m-2.min-1), lower limbs MV (mL.mL-1.min-1) and interaction body mass height (mL.kgm-1.min-1) a significant correlation among scaling variables and normalized VO2max remained (0.3 < r < 0.8, p<0.05). The allometric scaling of body mass (mL.kg-0.79.min-1), height (mL.m-2.18.min-1), BSA (mL.m-2.37.min-1), lower limbs MV (mL.mL-0.43.min-1) and interaction body mass height (mL.kgm-0.63.min-1) were effective to adjust the effect of body size on VO2max, with no significant correlation among scaling variables and normalized VO2max (p>0.05). CONCLUSION: Allometric scaling is best method to normalize VO2max in young soccer players.

Bone strength is related to muscle volume in ambulant individuals with bilateral spastic cerebral palsy

ObjectiveThe aim of this study is to investigate how bone strength in the distal femur and proximal tibia are related to local muscle volume in ambulant individuals with bilateral spastic cerebral palsy (CP). MethodsTwenty-seven participants with CP (mean age: 14.6±2.9years; Gross Motor Function Classification System (GMFCS) levels I-III) and twenty-two typically developing (TD) peers (mean age: 16.7±3.3years) took part in this study. Periosteal and medullary diameter in the distal femur and cortical bone cross-sectional area (CSA) and thickness (CT) in the distal femur and proximal tibia were measured along with nine lower limb muscle volumes using MRI. Additionally, the polar section modulus (Zp) and buckling ratio (BR) were calculated to estimate bone bending strength and compressional bone stability respectively in the distal femur. The relationships of all measured parameters with muscle volume, height, age, body mass, gender, and subject group were investigated using a generalized linear model (GZLM). ResultsIn the distal femur, Zp was significantly positively related to thigh muscle volume (p=0.007), and height (p=0.026) but not significantly related to subject group (p=0.076) or body mass (p=0.098). BR was not significantly different between groups and was not related to any of the variables tested. Cortical bone CSA was significantly lower in the CP group at both the distal femur (p=0.002) and proximal tibia (p=0.009). It was also positively associated with thigh muscle volume (p<0.001) at the distal femur, and with subject height (p=0.005) at the proximal tibia. ConclusionsBending and compressional strength of the femur, estimated from Zp and cortical bone CSA respectively, is associated with reduced thigh muscle volume. Increasing muscle volume by strength training may have a positive effect on bone mechanics in individuals with CP.

Lower limb muscle volumes in bilateral spastic cerebral palsy

Aim: Muscle weakness is a feature of individuals with spastic cerebral palsy (SCP) but there are few reports in the literature of muscle volume in this group. This study compares muscle volumes in adolescents and young adults with SCP with those of their typically developing (TD) peers. Design: Measurements of the volumes of nine major lower limb muscles in 19 independently ambulant subjects with SCP (mean age 14.2years (sd 2.7), 11 male, GMFCS I (n=5); GMFCS II (n=14)), 19 TD subjects (mean age 16.5years (sd 3.0), 11 male) were made using magnetic resonance imaging. Results: Lower limb muscles were smaller in the SCP group (p⩽0.023 in all muscles) than the TD group with the exception of the vastii (lateralis+intermedius; p=0.868) and gluteus maximus (p=0.056). Average muscle volume deficit was 27.9%. Muscle volume deficits were significantly greater for distal muscles than proximal muscles (p<0.001). Conclusions: Reduced muscle size in adolescence and the natural history of sarcopenia in adulthood may contribute to the early loss of mobility of adults with SCP.

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.

The exercise training effects of skeletal muscle strength and muscle volume to improve functional capacity in patients with myocardial infarction

BackgroundNo previous studies have fully investigated the exercise training effect on the skeletal muscle strength and volume to improve the exercise capacity in patients with myocardial infarction (MI). The present study was performed based on a hypothesis that the relationship between exercise capacity, skeletal muscle strength and volume might be changed by the amount of skeletal muscle volume in MI patients up to 3 months after the onset. MethodsSeventy patients with MI underwent symptom-limited cardiopulmonary exercise testing using a treadmill. The lower limb muscle volume (MV) was evaluated according to electrical impedance analysis and the maximal knee extension strength (Peak torque: PT) was measured by a Biodex. All patients participated in 12-week exercise training program. The subjects were divided into 2 groups on the basis of MV: Group H, MV≧22 kg; Group L, MV<22 kg. Delta values were calculated as follows: the value at 3 months minus the value at 1 month. ResultsA positive and significant correlation was observed between the delta PT and delta peak VO2 (r=0.50, p<0.005) only in the L group. No significant correlation was observed between the delta peak VO2 and the delta lower limb MV or between the delta lower limb MV and the delta PT in the 2 groups. ConclusionsCardiac rehabilitation program combined with resistance and aerobic training improved exercise capacity and increased not the skeletal muscle volume but the skeletal muscle strength in patients with MI in their recovery phase. It was presumed that the improvement of exercise capacity was determined by the skeletal muscle strength not by the muscle volume especially in MI patients with low muscle volume.

Functional Capacity, Skeletal Muscle Strength, and Skeletal Muscle Volume in Patients With Myocardial Infarction

Previous studies have reported that skeletal muscle strength is closely related to exercise capacity in patients with myocardial infarction (MI). However, none of the previous studies have fully investigated the correlation between exercise capacity and the skeletal muscle volume (MV). Seventy patients with MI underwent symptom-limited cardiopulmonary exercise testing using a treadmill. The MV was evaluated by electrical impedance analysis and the maximal knee extension strength (Peak torque: PT) was measured by a Biodex. The subjects were divided into 2 groups according to the MV (group L, MV < 22 kg; group H, MV > or = 22 kg). The PT was positively and significantly correlated with the peak V(.)O(2) in both the L and H groups (r = 0.70 versus r = 0.71). The MV of the lower limbs was positively correlated with the peak V(.)O(2) in the L group (r = 0.57), but not in the H group. The lower limb MV was positively and significantly correlated with PT in the L group (r = 0.48), but not in the H group. The exercise capacity of patients with MI is thought to depend on both the strength and volume of the skeletal muscle. In MI patients with high muscle volume, exercise capacity was determined by skeletal muscle strength alone.