The effect of skin cold stimulation on muscle activity during stair climbing in community-dwelling older adults

Abstract

  Skin cold stimulation (SCS) is an effective method for increasing electromyography (EMG) activity in walking. However, the effect of SCS on EMG response during stair climbing is unclear. Thus, this study aimed to investigate the effect of SCS on EMG response during stair climbing and compare the results with the change of EMG response in walking. Seventeen community-dwelling healthy older adults (73 ± 6 years old) participated in this study. All the participants performed stair climbing while EMG activity of the vastus lateralis (VL) was measured in SCS and without SCS (control; CON) condition. Furthermore, EMG data of stair climbing was compared with walking data. SCS significantly increased stair climbing speed upstairs (p = 0.035) and downstairs (p = 0.009). SCS increased root mean square EMG (rmsEMG) of VL from 0.098 ± 0.032 to 0.118 ± 0.042 mV (p < 0.01) and tended to decrease mean power frequency (MPF) of VL (p = 0.055) during upstairs climbing. SCS increased rmsEMG of VL from 0.065 ± 0.013 to 0.074 ± 0.019 mV (p < 0.01), but did not change MPF of VL (p = 0.358) during downstairs climbing. The change ratio was significantly different among walking and stair climbing (p = 0.020), and the ratio of rmsEMG of upstairs climbing was significantly greater than that of walking (p = 0.041). These results suggest that SCS increases EMG activity during stair climbing and is even more effective during upstairs climbing.