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Neural coordination mechanisms and adaptations following rapid movement practice and unlearning in young and elderly males
Abstract
Several factors, including the role of practice, have confounded the results of various strategies to counteract adverse aging effects on human motor control. Additionally, the biological degeneration that accompanies aging may result in elderly neuromuscular control mechanisms that are different from those in younger persons; mechanisms that need to be accounted for to effectively implement other rehabilitation methods. Neuromuscular control mechanisms, and the nature and extent of practice-related effects, were examined in sixteen older males (mean age = 61.4 years) and sixteen younger males (mean age = 20.0 years). Neuromuscular coordination was assessed by the triphasic electromyographic (EMG) pattern and corresponding kinematics from a maximally fast and accurate elbow flexion movement. Practice effects were examined over days 1 to 4 under loaded and unloaded inertial load conditions, and extended practice effects under a single load condition over days 5 to 8. Retention effects were assessed one month after day 8 (days 9 and 10). The results and conclusions were as follows: (1) Learning in younger and older individuals progressed with different strategies; after the initial day the young subjects concentrated on refining movement accuracy while the elders improved in speed; (2) Kinematic and EMG improvements with practice were limited to the unloaded conditions. The addition of external load saturated the neuromuscular control mechanisms, resulting in a neuromuscular control system that had little room for adaptations in the practice time provided; (3) Overall, the elders performed poorer than the young group with respect to kinematics, and differentially poorer when the movement was performed in the unloaded condition. Data from the present investigation suggested that the elders were at a disadvantage when rapid phasic muscle activation was necessary in the inherently faster unloaded movements; (4) Neither age group showed much evidence of performance decrement over the retention interval, and hence, there was no evidence of age-related forgetting; (5) Neither EMG or kinematic performance in either load condition was affected to a different extent by extended, load-specific practice. Thus, load-specific practice, at least after a baseline period of practice, can be considered equivalent with respect to transfer effects.
Subject Area
Physical education|Gerontology
Recommended Citation
Ives, Jeffrey C, "Neural coordination mechanisms and adaptations following rapid movement practice and unlearning in young and elderly males" (1992). Doctoral Dissertations Available from Proquest. AAI9305841.
https://scholarworks.umass.edu/dissertations/AAI9305841