H reflex latency in the healthy elderly.
The purpose of this study was to evaluate prospectively and analyze the relationship of tibial nerve H reflex latency to age, sex, leg length, and skin temperature in a large healthy elderly population. The H reflex was recorded bilaterally in 92% of 103 carefully screened individuals aged 60-88 years. The mean H reflex latency was 30.8 (SD = 2.6) and 30.7 (SD = 2.6) ms for right and left legs, respectively. A high correlation (r = 0.55, P < 0.05) was present between H reflex latency and leg length. No significant correlation existed for H reflex latency and age. The upper normal limit for the difference between right and left H reflex latencies was 1.8 ms. This limit is greater than that reported in the literature for younger individuals due to a larger standard deviation. These findings suggest that aging increases the between-leg variability of H reflex latency in individuals. This greater difference must be taken into account when using side-to-side H reflex latency comparison to detect unilateral pathology in the elderly.
Falco
F J
FJ
Georgia Spine & Sports Physicians, Smyrna 30080.
Hennessey
W J
WJ
Goldberg
G
G
Braddom
R L
RL
D000368:Aged; D000375:Aging / Q000502:physiology*; D000886:Anthropometry; D005260:Female; D006181:H-Reflex; D006801:Humans; D007866:Leg / Q000033:anatomy & histology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011930:Reaction Time; D012044:Regression Analysis; D012737:Sex Factors; D012881:Skin Temperature