NEUROMOTOR COORDINATION MECHANISMS, FRACTIONATED REACTION TIME, AND AGING (STRENGTH, LIMB VOLUME).

摘要

The fact that physical performance deteriorates concomitantly with the process of senescence is well-documented. However, little is actually known regarding the control mechanisms which induce the physiological dysfunction associated with age.;A repeated measures analysis of variance was employed to determine which data was the most stable. The analysis that there were few significant differences between the trials recorded on day 1 and day 2, indicating that performance had stabilized. Intraclass correlation analysis showed that the criterion measures were reliable.;Age group comparison revealed significant differences between the groups for: (1) maximum voluntary isometric strength, (2) maximum displacement, (3) agonist silent period, (4) accuracy, (5) resisted motor time and (6) resisted total reaction time. A non-significant age-related trend for the following parameters to be adversely affected with age was noted: (1) movement time, (2) agonist first burst motor time, (3) antagonist first burst motor time, (4) antagonist second burst duration, (5) agonist first burst integrated electromyographic slope, (6) antagonist second burst time to peak activity, (7) time to maximum acceleration, (8) agonist first burst peak amplitude, (9) antagonist second burst peak amplitude, and (10) acceleration as a percentage of movement time.;The purpose of this investigation was to evaluate the effect of age on neuromotor coordination mechanisms and fractionated reaction time parameters during the execution of ballistic forearm flexion and extension, maximum voluntary isometric forearm flexion and extension strength and limb volume. A total of 48 male subjects in three age groups were studied (16 in each group): (1) 30-40 years old, (2) 50-60 years old and (3) 61-70 years old. On each of four test days each of the following criterion measures were recorded: (1) two slow and two fast maximum voluntary isometric contractions of the flexors of one arm and the extensors of the other arm, (2) twenty simple reaction time trials of the flexors of one arm and the extensors of the other arm, (3) twenty simple resisted reaction time trials of the flexors of one arm and the extensors of the other and (4) twenty trials of speed of movement at two inertial loads for the flexors of one arm and the extensors of the other arm.