Sex-based differences in skeletal muscle function and morphology with short-term limb immobilization

2005 ◽  
Vol 99 (3) ◽  
pp. 1085-1092 ◽  
Author(s):  
Nobuo Yasuda ◽  
Elisa I. Glover ◽  
Stuart M. Phillips ◽  
Robert J. Isfort ◽  
Mark A. Tarnopolsky
Keyword(s):  
Muscle Strength ◽  
Lean Mass ◽  
Muscle Function ◽  
Knee Extensor ◽  
Quadriceps Femoris ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Short Term ◽  
Cross Sectional ◽  
Time Points

The purpose of this study was to determine the effects of short-term (14-day) unilateral leg immobilization using a simple knee brace (60° flexion)- or crutch-mediated model on muscle function and morphology in men (M, n = 13) and women (W, n = 14). Isometric and isokinetic (concentric-slow, 0.52 rad/s and fast, 5.24 rad/s) knee extensor peak torque was determined at three time points (Pre, Day-2, and Day-14). At the same time points, magnetic resonance imaging was used to measure the cross-sectional area of the quadriceps femoris and dual-energy X-ray absorptiometry scanning was used to calculate leg lean mass. Muscle biopsies were taken from vastus lateralis at Pre and Day-14 for myosin ATPase and myosin heavy chain analysis. Women showed greater decreases (Pre vs. Day-14) compared with men in specific strength (N/cm2) for isometric [M = 3.1 ± 13.3, W = 17.1 ± 15.9%; P = 0.055 (mean ± SD)] and concentric-slow (M = 4.7 ± 11.3, W = 16.6 ± 18.4%; P < 0.05) contractions. There were no immobilization-induced sex-specific differences in the decrease in quadriceps femoris cross-sectional area (M = 5.7 ± 5.0, W = 5.9 ± 5.2%) or leg lean mass (M = 3.7 ± 4.2, W = 2.7 ± 2.8%). There were no fiber-type transformations, and the decreases in type I (M = 4.8 ± 5.0, W = 5.9 ± 3.4%), IIa (M = 7.9 ± 9.9, W = 8.8 ± 8.0%), and IIx (M = 10.7 ± 10.8, W = 10.8 ± 12.1%) fiber areas were similar between sexes. These findings indicate that immobilization-induced loss of knee extensor muscle strength is greater in women compared with men despite a similar extent of atrophy at the myofiber and whole muscle levels after 14 days of unilateral leg immobilization. Furthermore, we have described an effective and safe knee immobilization method that results in reductions in quadriceps muscle strength and size.

Skeletal muscle adaptations following blood flow-restricted training during 30 days of muscular unloading

2010 ◽  
Vol 109 (2) ◽  
pp. 341-349 ◽  
Author(s):  
Summer B. Cook ◽  
Kimberly A. Brown ◽  
Keith DeRuisseau ◽  
Jill A. Kanaley ◽  
Lori L. Ploutz-Snyder
Keyword(s):  
Blood Flow ◽  
Muscle Strength ◽  
Knee Extensor ◽  
Exercise Group ◽  
Cross Sectional Area ◽  
Knee Extensors ◽  
Muscular Endurance ◽  
Sectional Area ◽  
Cross Sectional ◽  
Flow Restriction

This study evaluated the effectiveness of low-load resistance training with a blood flow restriction (LLBFR) to attenuate muscle loss and weakness after 30 days of unilateral lower limb suspension (ULLS). Sixteen subjects (ages 18–50 yr) underwent 30 days of ULLS. Measurements of muscle strength, cross-sectional area, and endurance on the knee extensors and plantar flexors were collected before and after ULLS. Plasma concentrations of IGF-1 and IGFBP-3 were also assessed. During ULLS, eight subjects (5 males, 3 females) participated in LLBFR three times per week (ULLS + Exercise) while eight subjects (4 males, 4 females) did not exercise (ULLS). The blood flow-restricted exercise consisted of dynamic knee extension at 20% of the subject's isometric maximum voluntary contraction coupled with a suprasystolic blood flow restriction. After 30 days of limb suspension, the ULLS + Exercise group experienced minimal and insignificant losses in knee extensor cross-sectional area and strength (1.2% and 2.0%, respectively; P ≤ 0.05), while the ULLS group demonstrated significant reductions in cross-sectional area and strength (7.4% and 21%, respectively). Decrements in plantar flexor strength (23.7%) and cross-sectional area (7.4%) were observed after ULLS ( P < 0.05) and were of similar magnitude between the experimental groups ( P > 0.05). Muscular endurance in the knee extensors improved 31% in the ULLS + Exercise group, while it decreased 24% in the ULLS group ( P = 0.01). No changes were seen in hormone concentrations throughout the study. In conclusion, LLBFR of the knee extensors is effective in maintaining muscle strength and size during 30 days of ULLS and results in improved knee extensor muscular endurance.

scholarly journals Histochemical muscle fibre characteristics of German Heath lamb meat

2015 ◽  
Vol 84 (3) ◽  
pp. 297-303
Author(s):  
Milena Fantová ◽  
Martin Ptáček ◽  
Klára Michnová ◽  
Lenka Nohejlová ◽  
Jaromír Ducháček
Keyword(s):  
Fibre Type ◽  
Quadriceps Femoris ◽  
Cross Sectional Area ◽  
Meat Industry ◽  
Sectional Area ◽  
Cross Sectional ◽  
Type Distribution ◽  
Fibre Type Distribution ◽  
Longissimus Lumborum ◽  
German Origin

Histochemical characteristics of muscle were evaluated in 12 German Heath lambs (6 males and 6 females). The lambs were slaughtered at the age of 150 days and samples of musculus longissimus lumborum et thoracis and quadriceps femoris were collected and measurements of fibre cross sectional area (µm2), diameter (µm2), and perimeter (µm2) were performed. Subsequently the fibre type distribution (%) was calculated. The dataset was evaluated using SAS 9.3. Significantly higher (P < 0.05) cross sectional area, diameter, and perimeter attributes were observed in females compared to males. Significant differences (P < 0.05 to 0.01) were observed in fibre type distribution between musculus longissimus lumborum et thoracis and quadriceps femoris muscle. The presented study describes evaluation of morphological formation of skeletal muscle tissue performed on a sheep breed of German origin. The results may be useful for meat scientists or meat industry due to close connection of these characteristics to meat quality.

scholarly journals Comparison of Muscle Cross-sectional Area and Lumbar Muscle Strength According to Degenerative Spinal Diseases

2020 ◽  
Vol 22 (2) ◽  
pp. 1-10
Author(s):  
Ji-Hoon Cho ◽  
Ki-Hyuk Lee ◽  
Seung-Taek Lim ◽  
Buong-O Chun
Keyword(s):  
Muscle Strength ◽  
Cross Sectional Area ◽  
Spinal Diseases ◽  
Sectional Area ◽  
Multifidus Muscle ◽  
Cross Sectional ◽  
Total Group ◽  
Male Group ◽  
The Difference ◽  
Lumbar Extension

OBJECTIVES The purpose of this study was to investigate the difference in the cross - sectional area (CSA) of multifidus and Iliopsoas muscles and the lumbar extension muscle strength according to degenerative spinal diseases (LHI; lumbar herniation of intervertebral disc group, SS; spinal stenosis group, S; spondylolisthesis group).METHODS The CSA of multifidus and Iliopsoas muscles size were measured by PACS(Picture Achiving and Communication System) using MRI at the L4/5 level and lumbar extension muscle strength (72˚, 60˚, 48˚, 36˚, 24˚, 12˚, 0˚) was measured using lumbar extension machine(MedX) in 97 patients of degenerative spinal diseases(male: 57, female: 40). The collected data were analyzed by one-way ANOVA using the SPSS program.RESULTS The results of this study showed that the CSA of total and right multifidus muscle in the LHI was significantly higher than that of the S (p <.05; p <.05) in the male group. The difference between the left and right CSA of multifidus in the LHI group was significantly higher than that of the SS (p <.05) in the male group (p <.05) and total group (p <.05). The CSA of iliopsoas muscle in the S was significantly higher than that of the LHI in the male and total group (p <.05; p <.05). In case of lumbar extension muscle strength, the S showed significantly higher muscle strength at 36 and 48 degrees than that of the SS in the male group. In the total group, LHI showed significantly higher muscle strength at 60 degrees of lumbar extension muscle strength than that of the S.CONCLUSION Multifidus muscle appears to be a key factor in prevention and treatment intervention in low back pain patients. In particular, in the case of S group, exercise therapy for strengthening the multifidus muscle is need for the rehabilitation.

scholarly journals Cross-sectional area of the paraspinal muscles and its association with muscle strength among fighter pilots: a 5-year follow-up

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Tuomas Honkanen ◽  
Matti Mäntysaari ◽  
Tuomo Leino ◽  
Janne Avela ◽  
Liisa Kerttula ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Paraspinal Muscles ◽  
Cross Sectional

scholarly journals The Effects of Calcium-β-Hydroxy-β-Methylbutyrate on Aging-Associated Apoptotic Signaling and Muscle Mass and Function in Unloaded but Nonatrophied Extensor Digitorum Longus Muscles of Aged Rats

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Brian T. Bennett ◽  
Junaith S. Mohamed ◽  
Stephen E. Alway
Keyword(s):  
Muscle Mass ◽  
Satellite Cells ◽  
Muscle Function ◽  
Extensor Digitorum Longus ◽  
Cross Sectional Area ◽  
Extensor Digitorum ◽  
Aged Rats ◽  
Sectional Area ◽  
Cross Sectional ◽  
Apoptotic Signaling

Beta-hydroxy-beta-methylbutyrate (HMB), a naturally occurring leucine metabolite, has been shown to attenuate plantar flexor muscle loss and increase myogenic stem cell activation during reloading after a period of significant muscle wasting by disuse in old rodents. However, it was less clear if HMB would alter dorsiflexor muscle response to unloading or reloading when there was no significant atrophy that was induced by unloading. In this study, we tested if calcium HMB (Ca-HMB) would improve muscle function and alter apoptotic signaling in the extensor digitorum longus (EDL) of aged animals that were unloaded but did not undergo atrophy. The EDL muscle was unloaded for 14 days by hindlimb suspension (HS) in aged (34-36 mo.) male Fisher 344×Brown Norway rats. The rats were removed from HS and allowed normal cage ambulation for 14 days of reloading (R). Throughout the study, the rats were gavaged daily with 170 mg of Ca-HMB or water 7 days prior to HS, then throughout 14 days of HS and 14 days of recovery after removing HS. The animals’ body weights were significantly reduced by ~18% after 14 days of HS and continued to decline by ~22% during R as compared to control conditions; however, despite unloading, EDL did not atrophy by HS, nor did it increase in mass after R. No changes were observed in EDL twitch contraction time, force production, fatigue resistance, fiber cross-sectional area, or markers of nuclear apoptosis (myonuclei + satellite cells) after HS or R. While HS and R increased the proapoptotic Bax protein abundance, BCL-2 abundance was also increased as was the frequency of TUNEL-positive myonuclei and satellite cells, yet muscle mass and fiber cross-sectional area did not change and Ca-HMB treatment had no effect reducing apoptotic signaling. These data indicate that (i) increased apoptotic signaling preceded muscle atrophy or occurred without significant EDL atrophy and (ii) that Ca-HMB treatment did not improve EDL signaling, muscle mass, or muscle function in aged rats, when HS and R did not impact mass or function.

Relationships between Muscle Strength and Cross-Sectional Area in Healthy Individuals

1982 ◽  
Vol 63 (3) ◽  
pp. 5P-5P ◽  
Author(s):  
R.J. Maughan ◽  
Jennifer S. Watson ◽  
J. Weir
Keyword(s):  
Muscle Strength ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Healthy Individuals ◽  
Cross Sectional

scholarly journals Role of TRPC1 channel in skeletal muscle function

2010 ◽  
Vol 298 (1) ◽  
pp. C149-C162 ◽  
Author(s):  
Nadège Zanou ◽  
Georges Shapovalov ◽  
Magali Louis ◽  
Nicolas Tajeddine ◽  
Chiara Gallo ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Function ◽  
Transient Receptor Potential ◽  
Force Production ◽  
Receptor Potential ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Skeletal Muscle Function ◽  
Cross Sectional

Skeletal muscle contraction is reputed not to depend on extracellular Ca2+. Indeed, stricto sensu , excitation-contraction coupling does not necessitate entry of Ca2+. However, we previously observed that, during sustained activity (repeated contractions), entry of Ca2+is needed to maintain force production. In the present study, we evaluated the possible involvement of the canonical transient receptor potential (TRPC)1 ion channel in this entry of Ca2+and investigated its possible role in muscle function. Patch-clamp experiments reveal the presence of a small-conductance channel (13 pS) that is completely lost in adult fibers from TRPC1−/−mice. The influx of Ca2+through TRPC1 channels represents a minor part of the entry of Ca2+into muscle fibers at rest, and the activity of the channel is not store dependent. The lack of TRPC1 does not affect intracellular Ca2+concentration ([Ca2+]i) transients reached during a single isometric contraction. However, the involvement of TRPC1-related Ca2+entry is clearly emphasized in muscle fatigue. Indeed, muscles from TRPC1−/−mice stimulated repeatedly progressively display lower [Ca2+]itransients than those observed in TRPC1+/+fibers, and they also present an accentuated progressive loss of force. Interestingly, muscles from TRPC1−/−mice display a smaller fiber cross-sectional area, generate less force per cross-sectional area, and contain less myofibrillar proteins than their controls. They do not present other signs of myopathy. In agreement with in vitro experiments, TRPC1−/−mice present an important decrease of endurance of physical activity. We conclude that TRPC1 ion channels modulate the entry of Ca2+during repeated contractions and help muscles to maintain their force during sustained repeated contractions.

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