Ankle position sense acuity does not decline in physically active older adults

Abstract

Ankle proprioception is essential for balance control. However, ankle proprioception can decline in older adulthood and has been linked to a higher incidence of falls. This study examined whether physically active older adults are spared from such proprioceptive decline. Using the Ankle Proprioceptive Acuity System (APAS) and applying an adaptive psychophysical testing paradigm, ankle position sense acuity in 57 neurotypical middle-aged and older adults (50-80 years) and 14 young adults (18-30 years) was assessed. A participants’ unloaded foot was passively rotated from a neutral joint position to a reference (15 or 25 deg plantarflexion) and a comparison position (< reference). Participants verbally indicated which position was further from neutral. Appropriate stimulus-response functions were fitted and Just-Noticeable-Difference (JND) thresholds and Uncertainty Areas (UA) were derived. The JND threshold is a measure of perceptual bias, while UA is a measure of precision. The main finding of the study: Between the middle-aged and older adult groups (50-60, 60-70, 70-80 years) no significant differences were found in JND threshold nor UA. These data indicate that active older adults may be spared from age-related decline in ankle position sense. These findings encourage older adults to become or remain active during aging.