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Muscle Physiology Lab |
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University of Massachusetts-Amherst |
30 Eastman Lane, 22 Totman Bldg Amherst, MA 01003 |
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| Phone: 413-545-5305 | ||||||
| Lab Director: Jane Kent-Braun, Ph.D. | ||||||
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Recently Completed Studies
Effects of aging and physical function on muscle energetics and fatigue
Researcher: Mike Tevald
Status: Manuscript in Preparation
Mike was investigating the magnitude and mechanisms of fatigue in older subjects with mild to moderate impairments in physical function. Subjects perform a fatiguing contraction protocol with the muscles of their lower leg while the energetic changes within the muscle were measured by NMR spectroscopy.
Effects of short-term, high-intensity exercise on mitochondrial function
Researcher: Ryan Larsen
Status: Manuscripts in preparation
Strength and Multiple Sclerosis
Researcher: Linda Chung
Status: Manuscripts In Preparation
What are the causes of muscle weakness in people with Multiple Sclerosis? Our main goal was to investigate the potential causes of muscle weakness in persons with MS, from changes at the central nervous system, to the effect of spasticity, to muscle size differences. Knowing the key components to muscle weakness will enable us to design appropriate therapeutic interventions in improving muscle strength and overall physical function. This research was supported, in part, by the National Multiple Sclerosis Society and the American College of Sports Medicine.
Knee Extensor Fatigue: Effects of Age & Velocity
Researcher: Damien Callahan
Journal: Journal of Applied Physiology
Damien was investigating fatigue in the knee extensor muscles, a large muscle group that undergoes many changes with age. While seated in a chair, subjects performed two types of muscle contractions. In one type of contraction (isometric contraction) the muscle was contracting but the knee does not extend. In the other type of contraction (isokinetic contraction), the leg extended at a constant speed.
Ryan was looking at the effects of age and physical activity level on the oxidative capacity of two functionally distinct muscle groups: the vastus lateralis (knee extensor) and the tibialis anterior (ankle dorsiflexors). Subjects performed a single contraction of each muscle group inside of a magnet and muscle energetics were measured using NMR spectroscopy.
Mike used magnetic resonance spectroscopy to estimate the energetic cost of an electrically stimulated twitch contraction in young and older volunteers. In old age, there is a shift towards slower, more economical muscle fiber types, which may contribute to the age-related differences in muscle energetics and fatigue that we and others have reported. Subjects performed three muscle stimulation protocols while lying in the magnet with energetic cost being measured using NMR spectroscopy.
For more completed studies, see our publications page