Plantar Parameters and Fall Risk in Community-Dwelling Older Adults with Sarcopenia

Abstract Background Sarcopenia is a geriatric syndrome marked by progressive reductions in skeletal muscle mass, strength, and function, and it is an independent risk factor for falls among community-dwelling older adults. Biomechanical alterations of the foot may contribute to declines in lower-limb function and the increased incidence of falls in individuals with sarcopenia. However, the characteristics of plantar force distribution in sarcopenic patients and their relationship with balance function remain unclear. Investigating this issue using the latest diagnostic criteria is clinically important. Objective To provide evidence for early identification of community-dwelling older adults at high risk for falls, this study examined differences in plantar force, plantar pressure, foot axis angle, and eversion angle between older adults with and without sarcopenia, and analyzed the relationships with balance function. Methods This cross-sectional study enrolled 99 community-dwelling older adults, with 66 in the sarcopenia group and 33 in the non-sarcopenia group. It measured plantar parameters-plantar force, plantar pressure, foot axis angle, and eversion angle-and evaluated balance function using the Tinetti Performance Oriented Mobility Assessment (POMA). The study compared intergroup differences in plantar parameters, examined correlations between these parameters and POMA scores, and identified independent factors influencing POMA scores through stepwise and hierarchical multiple linear regression analyses. Results Compared with the non-sarcopenia group, the sarcopenia group showed significantly lower plantar force at the left toes 2–5, left 2nd-3rd metatarsal heads, left lateral heel, right 2nd-3rd metatarsal heads, and right medial arch (all p < 0.05), and significantly larger left and right foot axis and eversion angles (all p < 0.001). No significant differences were observed in any plantar pressure parameter between the sarcopenia and non-sarcopenia group. Within the sarcopenia group, after correction, left foot axis angle ( r = 0.257, p = 0.037) and force at the left lateral heel ( r = 0.251, p = 0.042) were positively correlated with POMA scores. Stepwise regression identified age ( β = −0.535, p < 0.001) and left foot axis angle ( β = 0.217, p = 0.036) as independent factors associated with POMA scores, with an adjusted R 2 of 0.336. Hierarchical regression further confirmed that left foot axis angle explained an additional 4.7% of the variance in POMA scores beyond age (Δ R 2 = 0.047, Δ F = 4.573, p = 0.036). Conclusions Community-dwelling older adults with sarcopenia show abnormal changes in plantar force distribution and foot alignment (axis angle and eversion angle). After adjusting for confounding factors, the left foot axis angle was independently associated with balance decline, suggesting it could serve as an additional biomechanical marker for fall risk. Furthermore, these abnormalities may work together in the pathophysiological processes that lead to balance impairment.