Muscle fibre type grouping in high resolution ultrasound

Human skeletal muscle fibre type grouping and collateral re-innervation.

Reinnervated muscle fiber type-grouping-inevitable?

Muscle fiber-type grouping (‘clumping’) in cross-sections of patient muscle biopsies and the electrophysiological recordings of enlarged motor unit action potentials (MUAPs) are almost universally interpreted as peripheral nerve damage with subsequent reinnervation of denervated muscle fibers [1, 2]. Other electromyographic potentials, including nascent potentials, are indicators of early muscl...

Muscle fibre type and obstructive sleep apnea.

Muscular pharyngeal structural changes, as fibre type disproportion, have been described in patients affected by Obstructive Sleep Apnea (OSA) and in an animal experimental OSA model. The unsolved question is whether these muscular abnormalities are either secondary to a compensatory increased activity or due to a constitutionally determined reduction of slow-alpha motor neurons. In the present...

Tbx15 controls skeletal muscle fibre-type determination and muscle metabolism

Skeletal muscle is composed of both slow-twitch oxidative myofibers and fast-twitch glycolytic myofibers that differentially impact muscle metabolism, function and eventually whole-body physiology. Here we show that the mesodermal transcription factor T-box 15 (Tbx15) is highly and specifically expressed in glycolytic myofibers. Ablation of Tbx15 in vivo leads to a decrease in muscle size due t...

Effects of high intensity canoeing training on fibre area and fibre type in the latissimus dorsi muscle.

A high intensity short duration exercise training programme was undertaken by nine subjects on three occasions each week for nine weeks. Muscle samples from the latissimus dorsi were taken by needle biopsy, at rest, before and after training. The results revealed that there was no change in either Type I or Type II muscle fibre distribution following training. Type I fibre area did not alter si...