Influence of age on neuromuscular control during a dynamic weight-bearing task.
Neuromuscular control strategies might change with age and predispose the elderly to knee-joint injury. The purposes of this study were to determine whether long latency responses (LLRs), muscle-activation patterns, and movement accuracy differ between the young and elderly during a novel single-limb-squat (SLS) task. Ten young and 10 elderly participants performed a series of resistive SLSs (approximately 0-30 degrees) while matching a computer-generated sinusoidal target. The SLS device provided a 16% body-weight resistance to knee movement. Both young and elderly showed significant overshoot error when the knee was perturbed (p < .05). Accuracy ofthe tracking taskwas similar between the young and elderly (p = .34), but the elderly required more muscle activity than the younger participants (p < .05). The elderly group had larger LLRs than the younger group (p < .05). These results support the hypothesis that neuromuscular control of the knee changes with age and might contribute to injury.
Madhavan
Sangeetha
S
Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, IL, USA.
Burkart
Sarah
S
Baggett
Gail
G
Nelson
Katie
K
Teckenburg
Trina
T
Zwanziger
Mike
M
Shields
Richard K
RK
D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D002490:Central Nervous System / Q000502:physiology; D004576:Electromyography; D005080:Exercise Test; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007866:Leg / Q000502:physiology*; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D011795:Surveys and Questionnaires; D013647:Task Performance and Analysis; D013997:Time Factors; D014891:Weight Lifting / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology*; D055815:Young Adult