Relations between quantitative ultrasound assessment of calcaneus and grip and key pinch power in Japanese mountain village residents

Abstract

Purpose: It seems to be important to recognize bone health condition using a simple method in Japanese super-aged society. The aim of our study was to investigate whether grip and key pinch strength were associated with bone quality. Methods: Medical examinations were conducted of 337 adult residents (123 men, 214 women; average age of 64.7 years) of a mountain village. Bilateral grip and key pinch strength were measured. The sound of speed (SOS) of calcaneus was assessed using an ultrasound bone densitometer. Study participants were divided into non-osteoporotic and osteoporotic groups according to the relevant WHO classification to evaluate statistical significance by age-adjusted analysis. Stepwise linear regression was used to identify the predictor of SOS using the following factors as explanatory variables: age, height, weight BMI, grip and key pinch power strength in bilateral side. A P value of < .05 was regarded as statistically significant. Results: In age-adjusted analysis, significant associations were found between osteoporosis and BMI (OR 0.87, 95%CI 0.80–0.95), gender (OR 3.21, 95%CI 1.83–5.62), grip strength (right side:, OR 0.95, 95%CI 0.92–0.98; left side: OR 0.95, 95% CI 0.92–0.98) and key pinch strength (right side: OR 0.76, 95%CI 0.65–0.88; left side: OR 0.79, 95%CI 0.68–0.91). In stepwise linear regression, age and left key pinch strength were predictors of calcaneal SOS (age β coefficient = −0.46, P = .00; left key pinch strength β coefficient = 0.17, P = .0049). Conclusions: Key pinch strength assessment might be useful to predict calcaneal SOS in general population.