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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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Current Studies
Knee Extensor Fatigue: Effects of Age & Velocity
Researcher: Damien Callahan
Status: In Progress & Recruiting
Damien is investigating fatigue in the knee extensor muscles, a large muscle group that undergoes many changes with age. While seated in a chair, subjects perform two types of muscle contractions. In one type of contraction (isometric contraction) the muscle is contracting but the knee does not extend. In the other type of contraction (isokinetic contraction), the leg extends at a constant speed.
Ryan is 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 perform a single contraction of each muscle group inside of a magnet and muscle energetics are measured using NMR spectroscopy.
Mike is using 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 undergo three muscle stimulation protocols while lying in the magnet with energetic cost being measured using NMR spectroscopy.
Mike is 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 are measured by NMR spectroscopy.
What are the causes of muscle weakness in people with Multiple Sclerosis? Our main goal is 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 is supported, in part, by the National Multiple Sclerosis Society and the American College of Sports Medicine.
[Click here] if you are interested in participating in one of our studies