The purpose of this study was to clarify differences in motor function based on the presence or absence of “Locomotive syndrome” (LS) by conducting the LS risk test and assessing motor function measurements related to LS in young adults. The study included 124 undergraduate and graduate students (72 females). The LS risk tests (stand-up test, two-step test, and 25-question Geriatric Locomotive Function Scale (GLFS-25)) were used to determine LS. Motor function measurements included center of pressure measurement (single-leg standing with eyes open/closed), single-leg standing time with eyes open/closed, Functional Reach Test, Timed Up and Go Test (TUG), grip strength, and seated forward bending. Group comparisons were conducted separately by sex using independent t-tests or the Wilcoxon signed-rank tests. In total, 33 subjects (26.6%) were identified as having LS. Sex-specific group comparisons revealed significant differences in the male LS group in the stand-up test (p = 0.024) and GLFS-25 (p < 0.001). In contrast, the female LS group showed significant differences in the two-step test (t (27.55) = -2.397, p = 0.024), TUG (t (33.23) = 3.000, p = 0.005), left single-leg standing time with eyes closed (p = 0.021), and GLFS-25 (p < 0.001). These findings suggest that males with LS show lower-limb muscle weakness, while females with LS exhibit reduced composite mobility involving maintaining a large step length, standing up, walking, and sitting down. In other words, differences in motor function based on the presence or absence of LS were observed even in young adults.