Age-related hip proprioception declines: effects on postural sway and dynamic balance.

OBJECTIVE To evaluate the effects of age on hip proprioception, and determine whether age-related hip proprioception declines disrupt balance. DESIGN Survey of proprioception and balance differences between 3 age groups. SETTING University balance laboratory. PARTICIPANTS Volunteer sample of independent community-dwelling adults (N=102) without sensory or other neurologic impairments in 3 age groups: younger (mean age, 24.6y; range, 19-37y), mid-aged (mean age, 53.3y; range, 40-64y), and older adults (mean age, 76.3y; range, 65-94y). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Hip joint position sense (JPS) and kinesthesia were measured using a custom-built device. JPS error was determined by the magnitude of matching errors during vision and no-vision conditions. Kinesthesia was evaluated by the ability to detect passive limb rotation without vision. Postural sway was assessed during static stance and measured using root mean square of center of pressure (COP) displacement and velocity of COP displacement. Clinical balance and fear of falling were assessed with the mini-Balance Evaluation Systems Test (mini-BESTest) and Activities-specific Balance Confidence Scale, respectively. RESULTS Both older and mid-aged adults had significantly increased JPS error compared with younger adults (P<.05). Kinesthesia accuracy was significantly decreased in older adults compared with mid-aged and younger adults (P≤.01). Both measures of proprioception error correlated with age (P≤.001). There were no relationships between hip proprioception error and postural sway during static stance. However, older adults with lower proprioceptive error had significantly higher mini-BESTest scores of dynamic balance abilities (P=.005). CONCLUSIONS These results provide evidence of significant hip proprioception declines with age. Although these declines are not related to increases in postural sway, participants with hip proprioception declines demonstrated disrupted dynamic balance, as indicated by decreased mini-BESTest scores.