The effect of age on ankle versus hip proprioceptive contribution in balance recovery: application of vibratory stimulation for altering proprioceptive performance

While tripping is the leading cause of injurious falls in older adults, the influence of ankle and hip proprioceptive information in balance recovery among older adults is still not clearly understood. The objective of this study was to assess the influence of ankle vs. hip proprioceptive information by altering muscle spindle performance using vibratory stimulation among older adults and healthy young control participants. Two groups of young (n = 20, age = 22.2 ± 3.1 years) and older adult (n = 33, age = 74.0 ± 3.8 years) participants were recruited and went through treadmill perturbation (sudden backward treadmill movement mimicking a trip), while they were equipped with vibratory devices (no vibration, and 40 and 80 Hz) on either ankle or hip muscles. Kinematics of the recovery were measures using motion sensors on lower extremities and the trunk. Results showed that vibratory stimulation on ankle significantly influenced balance recovery response (i.e., increased reaction time by 18% and increased recovery step length by 21%) among healthy young control, while it showed no effect when placed on hip muscles. On the other hand, while vibratory stimulation on ankle showed no effect on balance recovery among older adults, it significantly influenced balance recovery when applied to the hip muscles (i.e., increased reaction time by 12% and increased recovery step length by 10%). Current findings suggest that the role of ankle vs. hip proprioceptive information in balance recovery may change by aging. Findings may potentially be used for targeting the appropriate location for balance interventions and reducing the fall risk in older adults.