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Program in occupational biomechanics: The effect of a muscle relaxant on the biomechanics of the patella reflex.
New York University Center for Safety, and Institute of Rehabilitation Medicine, New York University Medical Center, New York, N. Y., Master of Arts Thesis, 1971 Jan; :1-33
Thesis submitted to the New York University on the development of a device and technique for the simple and direct measurement of the biomechanical parameters of reflex movement, such as displacement, velocity, and acceleration. The biomechanical profile of the patella reflex of healthy subjects was studied. Testing was conducted with no medication, following administration of placebo, and following a single 10 milligram oral dose of diazepam. The effects of Jendrassik and arm exercise facilitation were studied. Diazepam caused a lengthening of reaction time and decreased maximum displacement, velocity, acceleration, and the vector sum of velocity and acceleration. Exercise facilitation following diazepam was highly effective, returning the reflex to almost its pre-drug condition. Placebo had no effect. Results indicate that Jendrassik and arm exercise facilitation exert their effects upon the patella reflex by augmenting recruitment of fast motor units, composed of white fibers, that diazepam blocks recruitment of the faster units, and that exercise facilitation circumvents this block. Diazepam is thought to affect reflex by decreasing supraspinal excitation. The data obtained are consistent with a principal site of action of diazepam upon the excitatory reticular formation.
NIOSH-Grant; Biomechanics; Reflex-action; Bioassay; Muscle-relaxants; Placebos; Drugs
Rehabilitation Medicine New York University Med Ctr 400 East 34 Street New York, N Y 10016
NTIS Accession No.
New York University Center for Safety, and Institute of Rehabilitation Medicine, New York University Medical Center, New York, N. Y., Master of Arts Thesis, 33 pages, 37 references
New York University, New York, New York
Page last reviewed: January 14, 2022
Content source: National Institute for Occupational Safety and Health Education and Information Division