Sex-dependent and sex-independent muscle activation patterns in adult gait as a function of age.

•Healthy aging affects muscle activation sex-dependently at mid-swing (MS) of gait.•Age-increase in gastrocnemius lateralis (GL) activity at MS was greater in females.•Healthy aging affects EMG signal variability sex-dependently during stance.•Age-increases in EMG signal variability at stance were greater in females.•Healthy aging associated with higher GL activation during gait, independent of sex.