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Reflex profile, phasic vibratory response, strength, reaction time, and speed of movement performance pre- and post- to patellar tendon tap training of able-bodied and disabled subjects
Abstract
Reflexive and voluntary performance in four test batteries was examined in 12 able-bodied and 12 disabled (6 spinal cord injured, 6 with cerebral palsy) subjects. The batteries, administered pre and post to 4 weeks of training, consisted of tests for patellar tendon tap reflex, phasic vibratory response, knee extension isometric strength, reaction time, and speed of movement. Training involved 120 patellar tendon taps per session, 3 sessions per week. The training patellar taps were paired with an auditory tone; one half of the subjects were trained with a loud (100 db) auditory tone, the remaining were trained with a soft (50 db) auditory tone. No significant difference was observed for reflexive agonist and antagonist EMG amplitude and reflexive peak force during the training or posttraining sessions. The expected habituation of reflexive response was not observed, but the impact force to elicit a maximum reflexive response increased across sessions. These findings suggest that the muscle spindles became less responsive with repeated sessions, but this decreased responsiveness was masked by the increased impact force. Pre to posttraining increases were observed in: tendon tap reflex long motor time and long reflex time; phasic vibratory response; maximum isometric knee extension strength; and velocity of movement in both groups. Posttraining changes in reflexive and voluntary responses were likely due to increased Ia afferent presynaptic inhibition and a more efficient muscle contraction. Auditory effects on reflexive and voluntary responses were mainly limited to a shortening of reaction premotor time especially in the disabled group. The loud tone increased the agonist EMG during the strength test, without a concurrent increase in maximum strength. Between group differences, with regard to spinal and supraspinal influences during the reflex profile, indicated that the gain in reflexive response was greater for the disabled subjects under spinal conditions, and greater for the able-bodied subjects under supraspinal conditions. Another finding revealed greater absolute antagonist reflexive responses, and greater relative antagonist voluntary responses of the disabled group compared to the able-bodied group under all conditions. Adaptations across training sessions and descriptive differences between groups provide insight into future research and rehabilitation strategies.
Subject Area
Occupational safety|Neurosciences|Physiological psychology|Physical education
Recommended Citation
Lambert, Nancy Jean, "Reflex profile, phasic vibratory response, strength, reaction time, and speed of movement performance pre- and post- to patellar tendon tap training of able-bodied and disabled subjects" (1990). Doctoral Dissertations Available from Proquest. AAI9100519.
https://scholarworks.umass.edu/dissertations/AAI9100519