title: Neuromuscular control of lifting in the elderly.
abstract: The aim of this investigation was to determine, utilising an electromyographic (EMG) technique, the influence of the ageing process on the neuromotor control of the stoop-lift. Seven elderly (60-75 years) and seven young (18-25 years) subjects completed a series of ten unresisted (no weight) stoop-lifts. EMG potentials were recorded with 4-mm bipolar surface electrodes from the erector spinae and medial hamstring muscle groups. The temporal features of the stoop-lift itself were recorded with an electrogoniometer. The results of this investigation showed that the elderly subjects had a significantly (p < 0.05) earlier onset of the erector spinae muscle during the up-phase of the stoop-lift compared to the younger subjects. In addition, reactivation of the erector spinae muscle in the up-phase occurred at hand positions significantly (p < 0.05) closer to the floor in the elderly group indicating more stooped postures. Thus the EMG profiles of the erector spinae within the elderly subjects performing unresisted stoop-lifts approximated those previously reported in younger subjects performing resisted (with a weight) lifting. The earlier onset of the erector spinae in the up-phase of the stoop-lift was partially explained by a significant (p < 0.05) reduction in flexibility (sit and reach test) associated with the elderly subjects. The results further stress the potential for injury associated with the utilisation of the stoop-lift, particularly by elderly populations.
authors.affiliation: Department of Biomedical Science, University of Wollongong, Australia.
authors.forename: J M
authors.initials: JM
authors.lastname: Brown
authors.forename: J H
authors.initials: JH
authors.lastname: Mills
authors.forename: A
authors.initials: A
authors.lastname: Baker
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D004576:Electromyography; D015444:Exercise / Q000502:physiology; D006801:Humans; D017770:Lifting; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D009424:Nervous System Physiological Phenomena