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Kinesiology

University of Massachusetts Amherst

Fatigue

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Full-Text Articles in Life Sciences

Stretch Activation During Fatigue Improves Relative Force Production In Fast-Contracting Mouse Skeletal Muscle Fibers, Philip C. Woods Apr 2023

Stretch Activation During Fatigue Improves Relative Force Production In Fast-Contracting Mouse Skeletal Muscle Fibers, Philip C. Woods

Masters Theses

Stretch activation (FSA) is the delayed increase in fiber specific tension (force per cross-sectional area) following a rapid stretch and can improve muscle performance during repetitive cyclical contractions. Historically considered minimal in skeletal muscle, our recent work showed the ratio ofstretch- to calcium-activated specific tension (FSA/F0) increased from 10 to 40% with greater inorganic phosphate (Pi) levels in soleus muscle fibers (Straight et al., 2019). Given Pi increases with muscle fatigue, we hypothesize that FSA helps maintain force generation during fatigue. To test this, FSA, induced by a stretch of 0.5% …


Tropomyosin-Based Effects Of Acidosis On Thin-Filament Regulation During Muscle Fatigue, Brent Scott Jul 2019

Tropomyosin-Based Effects Of Acidosis On Thin-Filament Regulation During Muscle Fatigue, Brent Scott

Masters Theses

Skeletal muscle fatigue is defined as a loss in the force/velocity generating capacity of a muscle. A portion of the loss in function is attributable to effects of acidosis (i.e. low pH) on the regulatory proteins, troponin and tropomyosin (Tm), which regulate the binding of myosin and actin in a calcium (Ca++) dependent manner. However, the relative role of troponin and Tm on myosin-actin function during acidosis is not clear, nor are the mechanisms underlying these effects. PURPOSE: To determine the role of Tm in the acidosis-induced depression of muscle function using isolated muscle proteins in an in …


Recovery From Muscle Fatigue In Young And Older Adults: Implications For Physical Function, Stephen A. Foulis Sep 2013

Recovery From Muscle Fatigue In Young And Older Adults: Implications For Physical Function, Stephen A. Foulis

Open Access Dissertations

As adults age, skeletal muscles become smaller and weaker, which can ultimately lead to declines in physical function and disability. In general, older adults produce less isometric force and dynamic power than younger adults. The effects of this weakness are amplified following a series of muscle contractions that result in muscle fatigue. Since daily routines consist of repeated series of activity followed by rest, it is important to understand how muscle recovers from fatigue. In particular, muscle power has been shown to be related to physical function and balance. Thus, understanding the process of recovery from muscle fatigue will help …


Recent Insights Into Muscle Fatigue At The Cross-Bridge Level, Edward Debold Jun 2012

Recent Insights Into Muscle Fatigue At The Cross-Bridge Level, Edward Debold

Edward P. Debold

The depression in force and/or velocity associated with muscular fatigue can be the result of a failure at any level, from the initial events in the motor cortex of the brain to the formation of an actomyosin cross-bridge in the muscle cell. Since all the force and motion generated by muscle ultimately derives from the cyclical interaction of actin and myosin, researchers have focused heavily on the impact of the accumulation of intracellular metabolites [e.g., Pi, H+ and adenosine diphoshphate (ADP)] on the function these contractile proteins. At saturating Ca++ levels, elevated Pi appears to be the primary cause for …