Biomechanical characteristics of the picking-up task related to balance and mobility among community-dwelling older adults

<title>Abstract</title> <p>Background Picking up objects is a common daily activity among older adults that may increase the risk of falls and is a leading cause of disability and mortality. This study aimed to investigate the associations between balance and mobility and biomechanical characteristics during a picking-up task and to identify biomechanical characteristics of poor balance and mobility in older adults. Methods Volunteers were assessed via the Community Balance and Mobility Scale (CB&amp;M). Motion analysis was performed via a three-dimensional optical motion capture system. Spearman’s rank correlation was used to examine associations, and binary logistic regression was conducted to identify characteristics of poor balance and mobility. Results During reaching down, CB&amp;M scores were negatively correlated with the height of the right acromion and C7 and positively correlated with the bilateral squatting angle and right eccentric hip extensor power. At the start of lifting, scores were negatively correlated with C7 height and positively correlated with the vertical acceleration of the bilateral acromia, C7, T12, right elbow, right wrist, and center of mass. During lifting, the scores were negatively correlated with the vertical acceleration of C7. Logistic regression revealed that the right squatting angle (odds ratio [OR] = 0.83, 95% confidence interval [CI]: 0.71–0.97, p = 0.022) and right eccentric hip extensor power (OR = 0.19, 95% CI: 0.04–0.85, p = 0.030) during reaching down were significant biomechanical characteristics correlated with poor B&amp;M. Conclusions The maintenance of an upright trunk posture with reduced hip control movement during reaching down may represent important biomechanical considerations for balance and mobility interventions in older adults.</p>