Active head movements facilitate compensation for effects of prism displacement on dynamic gait.
METHODS
Four groups, between-subjects study.


OBJECTIVE
To investigate the effects of exercise on adaptation of normal subjects who had been artificially spatially disoriented.


BACKGROUND
Many patients referred for rehabilitation experience sensory changes, due to age or disease processes, and these changes affect motor skill. The best way to train patients to adapt to these changes and to improve their sensorimotor skills is unclear. Using normal subjects, we tested the hypothesis that active, planned head movement is needed to adapt to modified visual input.


METHODS
Eighty male and female subjects who had normal balance on computerized dynamic posturography (CDP) and the dynamic gait index (DGI), were randomly assigned to four groups. All groups donned diagonally shift lenses and were again assessed with CDP and DGI. The four groups were then treated for 20 min. Group 1 (control group) viewed a video, Group 2 performed exercise that involved translating the entire body through space, but without separate, volitional head movement, Group 3 performed exercises which all incorporated volitional, planned head rotations, and Group 4 performed exercises that involved translating the body (as in Group 2) and incorporated volitional, planned head motion (as in Group 3). All subjects were post-tested with CDP and DGI, lenses were removed, and subjects were retested again with CDP and DGI.


RESULTS
The groups did not differ significantly on CDP scores but Groups 3 and 4 had significantly better DGI scores than Groups 1 and 2.


CONCLUSIONS
Active head movement that is specifically planned as part of the exercise is more effective than passive attention or head movements that are not consciously planned, for adapting to sensorimotor change when it incorporates active use of the changed sensory modality, in this case head motion.
Gottshall
Kim R
KR
Department of Defense Spatial Orientation Center, Naval Medical Center San Diego, CA 92134, USA. krgottshall@nmcsd.med.navy.mil
Hoffer
Michael E
ME
Cohen
Helen S
HS
Moore
Robert J
RJ
D000222:Adaptation, Physiological; D000328:Adult; D003221:Confusion / Q000534:rehabilitation*; D015444:Exercise / Q000502:physiology*; D005260:Female; D005684:Gait / Q000502:physiology*; D019416:Head Movements / Q000502:physiology*; D006801:Humans; D008297:Male; D011187:Posture / Q000502:physiology; D014722:Vestibule, Labyrinth / Q000502:physiology; D014785:Vision, Ocular / Q000502:physiology