The relation between occlusal force and general motor ability induced by lower-limb musculature is unclear. To identify indicators of oral and lower-limb muscle weakness, this study examined the relation between masticatory muscle strength and lower limb muscle force in 742 community-dwelling elderly adults (315 men and 427 women, mean age 73.3 ± 5.5 years) living in Itabashi ward, Tokyo. Multiple regression analysis of the relation between occlusal force and knee extension torque, in relation to age and sex, showed a significant correlation between the two variables (r = 0.348, P < 0.001), which indicates that occlusal force is a determinant of knee extension torque. Occlusal force remained significantly correlated with knee extension torque after adjustment for factors known to be related to the latter. In conclusion, chewing function and lower-limb motor function were significantly correlated and thus might be indicators of muscle weakness in elderly adults.