Relationship Of Strength, Proprioception, Sensation, To Dynamic/static Postural Stability Among Older Adults With Sensory Deficits

Sensory deficits affect postural stability and increase the risk of falls in older adults. Currently, the relationship of muscle strength, proprioception, and tactile sensation to dynamic and static postural stability in older sensory deficit adults is still unclear. PURPOSE:This study aimed to explore the relationship between these three factors and dynamic and static postural stability. METHODS:Forty-five older adults (female = 22, age = 68.3 ± 3.3 years, height = 162.7 ± 6.8 cm, body mass = 64.3 ± 10.0 kg) with sensory deficits (unable to detect a 5.07 Semmes-Weinstein monofilament on plantar positions) were recruited. Dynamic and static postural stability as indicated by Berg Balance Scale (BBS) and the root mean square (RMS) of the center of pressure (CoP) in the anteroposterior (AP) and mediolateral (ML) direction during quiet stance. Muscle strength, proprioception thresholds, and plantar tactile sensations were tested by a IsoMed 2000 strength testing system at an angular velocity of 60°/s, proprioception test devices, and Semmes-Weinstein monofilaments, respectively. A partial correlation was used to explore the correlations of the BBS and CoP-RMS with each of the strength, proprioception, and tactile sensation variables while controlling for covariates (age, height, and body mass). RESULTS:Muscle strength of ankle plantarflexion (r = 0.768, p < 0.001) was highly correlated with BBS, and ankle dorsiflexion (r = 0.585, p < 0.001) and hip abduction (r = 0.562, p < 0.001) were moderately correlated with BBS. Proprioceptive of the ankle plantarflexion (r = -0.431, p = 0.005) and dorsiflexion (r = -0.458, p = 0.003) were moderately correlated with BBS, and knee flexion (r = -0.335, p = 0.032) was weakly correlated with BBS. Tactile sensation at the 5th metatarsal head (r = -0.347, p = 0.026) was weakly correlated with BBS. Tactile sensation at the arch (r = 0.428, p = 0.005) was moderately correlated with CoP-RMSAP. CONCLUSIONS:In older adults with sensory deficits, muscle strength and proprioception are related to dynamic postural stability, whereas tactile sensation is related to static postural stability.