Role of a single session of ball throwing exercise on postural control in older adults with mild cognitive impairment.

Purpose: The purpose of the study was to investigate the role of training in improvement of balance control in older adults with mild cognitive impairment.

Methods: Older adults (mean age 78) with mild cognitive impairment (MCI) and cognitively intact older adults (mean age 72) were exposed to self-initiated perturbations while performing bilateral shoulder flexion task before and after a single training session consisting of throwing a medicine ball. EMG activity of six trunk and lower limb muscles was recorded. Muscle onsets, integrals of EMG, and muscle co-contraction (C) and reciprocal (R) activation indices were calculated and analyzed during the anticipatory and compensatory phases of postural control.

Results: Anticipatory postural adjustments (APAs) were observed in both groups.  Individuals with MCI, as compared to controls, had higher level of co-contraction of muscles. The training resulted in enhancement of the generation of APAs in individuals with MCI seen as earlier onset of leg and trunk muscle activity prior to the bilateral arm flexion task. While smaller co-contraction of muscles post-training was seen in both the groups, the effect of a single training session was significant in control subjects only.

Conclusions: The outcome of the exploratory study suggests that perturbation-based training could be used to improve balance control in older adults with and without mild cognitive impairment.