Author(s): NAKAMOTO, A., OHARA, K., NAKATA, H., ITO, K., SHIBASAKI, M., OHTAKA, C., Institution: NARA WOMEN'S UNIVERSITY, Country: JAPAN, Abstract-ID: 848

INTRODUCTION:
Age-related changes in gait are characterized by reduced walking speed, shorter step length, and altered plantar loading patterns, which contribute to decreased mobility and an increased risk of falls in older adults [1]. Dynamic plantar pressure during walking is known to change with age, reflecting alterations in gait mechanics [2]. Although exercise interventions are recommended for the preservation of gait function, some older adults have difficulty maintaining a regular exercise schedule due to chronic pain or physical burden. It has been reported that age-related declines in plantar sensory function are associated with impaired balance and altered gait mechanics [3], suggesting that interventions aimed at enhancing plantar sensory input may contribute to improvements in gait function in older adults. Therefore, the purpose of this study was to investigate the effect of continuous low-frequency electrical stimulation intervention to the lower limbs on gait function in older adults.
METHODS:
Thirty-six participants aged ≧65 years without dementia were recruited. Participants underwent an 8-week intervention consisting of low-frequency electrical stimulation applied to the plantar surface of their feet for 30 min per day, at least twice per week. Free walking was measured before and after the intervention using a plantar pressure plate. Spatiotemporal gait parameters (walking speed, step length, and cadence) and plantar pressure distribution were analyzed. The 1st-peak was defined as the first plantar pressure peak at foot flat following heel contact, the Minimum was defined as the lowest value during mid-stance between the two peaks, and the 2nd-peak was defined as the first peak during push-off after the Minimum. Differences between each peak and the Minimum were calculated as the magnitudes of change (1st, 2nd-peak to Minimum amplitude). Variables were analyzed by paired t-tests to compare pre- and post-intervention data.
RESULTS:
Contact time significantly reduced from pre- to post-intervention (p < 0.01), while walking speed increased (p < 0.05). In addition, the 1st-peak of plantar pressure significantly increased from pre- to post-intervention (p < 0.01).
CONCLUSION:
An 8-week intervention with low-frequency electrical stimulation applied to the plantar surface of the feet increased the first peak of plantar pressure and resulted in a clearer bimodal waveform characterized by distinct heel contact and push-off phases. Together with improvements in spatiotemporal gait parameters, these findings indicate that age-related flattening of the bimodal plantar pressure pattern was partially reversed, with a clearer differentiation between heel contact and push-off phases following the intervention.