We examined the effects of aging and lower limb sensory deficits (LLSD) on whole body control. Performances of a reaching task involving a step were measured in subjects with LLSD and young and older controls. Having LLSD was accompanied with greater reach errors and variability in lateral step deviations. Aging effects explained the smaller step deviations and longer movement times. These results suggest that older adults with LLSD have performance declines associated with deficits of the disease and aging that often differ, at least for this goal-directed discrete task. Furthermore, longer MT for older controls and shorter MT for LLSD subjects were associated with greater movement coupling. Longer movement periods likely offered older controls time to use sensory feedback to maintain good endpoint accuracy. Evidently, somatosensations from the limbs used during performance of whole body movements are required for the most accurate goal-directed control.
The authors are with Louisiana State University–Kinesiology, Baton Rouge, LA.