In Japan, nursing care is advised for patients with locomotive syndrome (LS) because of musculoskeletal disorders. Balance tests have indicated an association between LS risk and sway size related to center of pressure (COP) movement. Here, the power spectrum represents the energy contained in each frequency of COP sway. Although balance tests are often performed during health checkups, no studies have investigated the relationship between the power spectrum and LS. This study investigated this relationship. In total, 605 recipients of health checkups were evaluated for LS using the 25-item Geriatric Locomotive Function Scale. Power spectrums were calculated by applying fast Fourier transform to COP sway time-series data. These were classified into three sections (0.02-0.2 Hz [low-frequency band; LFB], 0.2-2 Hz [mid-frequency band], and 2-10 Hz [high-frequency band; HFB]). Power spectrums were evaluated in left-right and front-back directions. LS was associated with significantly lower ratios for both the HFB (P = 0.001) in the left-right direction and LFB (P = 0.007) in the front-back direction. In addition, men had significantly lower HFB ratios in the left-right direction (P = 0.032) and LFB ratios in the front-back (P = 0.013), whereas women had significantly lower HFB ratios in the left-right direction (P = 0.007). LS was associated with significantly lower ratios for both the HFB in the left-right direction and LFB in the front-back direction. This understanding of the power spectral characteristics of LS may be useful in the context of pathology and therapeutic intervention. Geriatr Gerontol Int ••; ••: ••-•• Geriatr Gerontol Int 2020; ••: ••-••.