Training Related Enhancements in Anticipatory Postural Adjustments in Healthy Older Adults

Balance control in older adults is diminished as a result of impaired anticipatory postural adjustments (APAs). An optimal APA is marked by early onset of muscle activation prior to the moment of perturbation. Our recent study demonstrated that APAs in older adults could be improved with a single session training of catching a ball. The aim of the present study was to see if longer training leads to enhancement of APAs and overall balance capacity in older adults, and if this improvement is retained after the training. Six older adults (73.3±5.0 years) were randomly assigned into the Experimental (EG) and Control (CG) groups. The EG participated in APA-based training that included 3 sessions per week (total of 12 sessions over 4 weeks) of catching of 2lbs/4lbs medicine ball while standing in 4 different body stability positions, and the CG that did not participate in the ball-catching training. Subjects in both of the groups were assessed three times (pre-training, post-training, and one month after training (retention)) using predictable external perturbation applied to the upper body during which electrical activity (EMG) of trunk and leg muscles was recorded. Clinical tests of balance (Timed-Up and Go, Single limb stance, and Activities-specific Balance Confidence scale) were implemented. As a result of APA-based training, postural activity in anticipation of the perturbation in the EG occurred earlier as compared to the pre-training condition in Medial gastrocnemius (MG), Biceps Femoris (BF) and External Oblique (EO) muscles while the same three muscles showed worsening in CG. The effect of APA-based training was seen in the improved outcomes of clinical tests of balance in the EG but not in the CG. Improvements in clinical outcome measures in EG as compared to the control group reveal the translation of the effect of APA-based training into improved balance and functional performance The study outcome for the first time provides support for the feasibility of a long-term APA-based training in enhancement of balance control of healthy older adults.