An accessory soleus muscle is a rare anatomical variant. Clinical awareness of this entity and the appropriate use of magnetic resonance imaging (MRI) can yield a definitive diagnosis in those patients with symptomatic accessory muscles. A case is presented in which the unique sensitivity of MRI in the evaluation of exertional muscle injuries proved useful in the detection of an accessory soleu...

Blood flow capacity in skeletal muscle declines with age. Reduced blood flow capacity may be related to decline in the maximal vasodilatory capacity of the resistance vasculature. This study tested the hypothesis that aging results in impaired vasodilatory capacity of first-order (1A) arterioles isolated from rat-hindlimb locomotory muscle: 1A arterioles (90-220 microm) from gastrocnemius and s...

A possible role of extracellular Cl(-) concentration ([Cl(-)](o)) in fatigue was investigated in isolated skeletal muscles of the mouse. When [Cl(-)](o) was lowered from 128 to 10 mM, peak tetanic force was unchanged, fade was exacerbated (wire stimulation electrodes), and a hump appeared during tetanic relaxation in both nonfatigued slow-twitch soleus and fast-twitch extensor digitorum longus ...

The purpose of this study was to investigate potential differences in single-fiber contractile physiology of fibers with the same myosin heavy chain isoform (MHC I and MHC IIa) originating from different muscles. Vastus lateralis (VL) and soleus biopsies were obtained from 27 recreationally active females (31 +/- 1 yr, 59 +/- 1 kg). A total of 943 single fibers (MHC I = 562; MHC IIa = 301) were...

BACKGROUND/AIMS The purpose of the study was to assess the amount of rRNA and phosphorylation status of the key markers of mTORC1-dependent (70s6k, 4E-BP1) and mTORC1-independent (GSK-3β, AMPK) signaling pathways controlling protein synthesis in rat soleus during early stages of mechanical unloading (hindlimb suspension (HS) for 1-, 3- and 7 days). METHODS The content of the key signaling mol...

The role of satellite cells and DNA unit size in determining muscle size was examined by inhibiting postnatal skeletal muscle development by using hindlimb suspension. Satellite cell mitotic activity and DNA unit size were determined in the soleus muscles from hindlimb-suspended and age-matched weight-bearing rats before the initiation of hindlimb suspension, at the conclusion of a 28-day hindl...

Microcurrent electrical nerve stimulation (MENS) has been used to facilitate recovery from skeletal muscle injury. However, the effects of MENS on unloading-associated atrophied skeletal muscle remain unclear. Effects of MENS on the regrowing process of unloading-associated atrophied skeletal muscle were investigated. Male C57BL/6J mice (10-week old) were randomly assigned to untreated normal r...

Sensorimotor cortex exerts both short-term and long-term control over the spinal reflex pathways that serve motor behaviors. Better understanding of this control could offer new possibilities for restoring function after central nervous system trauma or disease. We examined the impact of ongoing sensorimotor cortex (SMC) activity on the largely monosynaptic pathway of the H-reflex, the electric...