Search results for "Gastrocnemius"
showing 10 items of 54 documents
The Medial Sural Artery Perforator Free Flap
2001
The medial sural artery supplies the medial gastrocnemius muscle and sends perforating branches to the skin. The possible use of these musculocutaneous perforators as the source of a perforator-based free flap was investigated in cadavers. Ten legs were dissected, and the topography of significant perforating musculocutaneous vessels on both the medial and the lateral gastrocnemius muscles was recorded. A mean of 2.2 perforators (range, 1 to 4) was noted over the medial gastrocnemius muscle, whereas in only 20 percent of the specimens was a perforator of moderate size noted over the lateral gastrocnemius muscle. The perforating vessels from the medial sural artery clustered about 9 to 18 cm…
Effects of power training on muscle structure and neuromuscular performance
2005
The present study examines changes in muscle structure and neuromuscular performance induced by 15 weeks of power training with explosive muscle actions. Twenty-three subjects, including 10 controls, volunteered for the study. Muscle biopsies were obtained from the gastrocnemius muscle before and after the training period, while maximal voluntary isometric contractions (MVC) and drop jump tests were performed once every fifth week. No statistically significant improvements in MVC of the knee extensor (KE) and plantarflexor muscles were observed during the training period. However, the maximal rate of force development (RFD) of KE increased from 18,836+/-4282 to 25,443+/-8897 N (P0.05) durin…
Effects of power training on mechanical efficiency in jumping.
2003
The present study investigates the effects of power training on mechanical efficiency (ME) in jumping. Twenty-three subjects, including ten controls, volunteered for the study. The experimental group trained twice a week for 15 weeks performing various jumping exercises such as drop jumps, hurdle jumps, hopping and bouncing. In the maximal jumping test, the take-off velocity increased from 2.56 (0.24) m.s(-1) to 2.77 (0.18) m.s(-1) ( P<0.05). In the submaximal jumping of 50% of the maximum, energy expenditure decreased from 660 (110) to 502 (68) J.kg(-1).min(-1) ( P<0.001) while, simultaneously, ME increased from 37.2 (8.4)% to 47.4 (8.2)% ( P<0.001). Some muscle enzyme activities of the ga…
Localization of Muscle Edema and Changes on Muscle Contractility After Dry Needling of Latent Trigger Points in the Gastrocnemius Muscle.
2019
Background Myofascial trigger points (TrPs) are hyperirritable spots within taut bands of skeletal muscles that elicit local and referred pain when stimulated. Among the variety of techniques used for treating TrPs, dry needling (DN) is the most commonly applied intervention. The physiological mechanisms underlying the effects of DN remain to be elucidated. Objective To examine changes in skeletal muscle after DN in the area where the TrP is located. Methods We measured in vivo changes that occur in human skeletal muscle one hour after DN over a TrP with magnetic resonance imaging (MRI) and tensiomyography. The study included 18 asymptomatic subjects with a latent TrP in one medial gastrocn…
Differences in contractile behaviour between the soleus and medial gastrocnemius muscles during human walking
2012
The functional roles of individual lower limb muscles during human walking may differ depending on walking speed or duration. In this study, 11 volunteers walked on a treadmill for 60 min at speeds corresponding to both optimal and 20% above optimal energetic cost of transport whilst oxygen consumption and medial gastrocnemius (MG) and soleus fascicle lengths were measured. Although energetic cost of transport was ∼12% higher at the faster speed, it remained constant over 60 min at both speeds, suggesting that humans can walk for prolonged periods at a range of speeds without compromising energetic efficiency. The fascicles of both muscles exhibited rather ‘isometric’ behaviour during the e…
In vivo muscle mechanics during locomotion depend on movement amplitude and contraction intensity
2001
The effects of movement amplitude and contraction intensity on triceps surae and quadriceps femoris muscle function were studied during repetitive hopping. In vivo forces from Achilles and patellar tendons were recorded with the optic fibre technique from eight volunteers. The performances were filmed (200 Hz) to determine changes in muscle-tendon unit length and velocity. When hopping with a small amplitude (23 degrees knee flexion during the ground contact phase), the Achilles tendon was primarily loaded whereas patellar tendon forces were greater in large-amplitude hopping (56 degrees knee flexion). In spite of the different magnitudes of stretch in the quadriceps femoris muscle, the str…
The reliability of measuring medial gastrocnemius muscle-tendon unit lengths during gait
2021
Background Ultrasound imaging combined with 3D motion analysis allows for in-vivo assessment of muscle-tendon unit lengths during gait. The clinical relevance of analysing the medial gastrocnemius (MG) and Achilles muscle-tendon junction (MTJ), MG mid-muscle belly fascicles (FAS) and muscle thickness was shown. However, their reliability error estimations over the gait cycle is unknown. Research question What are the intra- and inter-session errors associated with extracting MG belly, thickness, FAS and tendon lengths using ultrasound during gait in healthy participants? Methods 3D gait analysis was carried out in ten healthy adults as they walked on an instrumented treadmill at a comfortab…
Neuromuscular mechanics and hopping training in elderly.
2014
Purpose The present study examined the effects of repetitive hopping training on muscle activation profiles and fascicle–tendon interaction in the elderly. Methods 20 physically active elderly men were randomly assigned for training (TG) and control groups (CG). TG performed supervised bilateral short contact hopping training with progressively increasing training volume. Measurements were performed before the training period (BEF) as well as after 2 weeks (2 W) and 11 weeks (11 W) of training. During measurements, the gastrocnemius medialis–muscle (GaM) fascicle and its outer Achilles tendon length changes during hopping were examined by ultrasonography together with electromyographic (EMG…
NO synthase II in mouse skeletal muscle is associated with caveolin 3
1999
The inducible-type NO synthase (NOS II; iNOS) is constitutively expressed in slow-twitch skeletal muscle fibres of guinea-pigs [Gath, Closs, Gödtel-Armbrust, Schmitt, Nakane, Wessler and Förstermann (1996) FASEB J. 10, 1614-1620]. Here we studied the expression of NOS II in skeletal muscle of wild-type and NOS II-deficient mice and investigated the molecular basis for the membrane association of this NOS in muscle. A basal expression of NOS II mRNA and protein was detected in skeletal muscle from untreated wild-type mice; expression increased when mice were treated with bacterial lipopolysaccharide (LPS). No NOS II was found in any tissue of untreated or LPS-treated NOS II-deficient mice. I…
Non-uniform displacement and strain between the soleus and gastrocnemius subtendons of rat Achilles tendon
2018
Achilles tendon (AT) comprises of 3 subtendons arising from the soleus (SOL) and the lateral (LG) and medial (MG) heads of the gastrocnemius muscle. While recent human studies show differential displacement within AT, these displacements have not been attributed to specific subtendons. We tested the hypothesis that the SOL and LG subtendons show differential displacement and strain during various combinations of SOL, LG, and MG excitations. Movement of knots, sutured onto SOL and LG subtendons of 12 Wistar rats, was videotaped, while the muscles were stimulated intramuscularly and ankle torque was assessed. When SOL only was stimulated, the plantar flexion torque was the smallest among the …