Ankle muscles co-activation patterns during normal gait: An amplitude evaluation

The objective of this work was to quantify co-activations of ankle muscles during able-bodied walking, in terms of amplitude values of surface electromyographic signal (sEMG). Gastrocnemius lateralis (GL) was analyzed as representative muscles for plantar-flexion. Tibialis anterior (TA) was analyzed as representative muscles for dorsi-flexion. Rudolph’s dynamic co-activation index was computed on the sEMG acquired from 182 strides, with the aim of quantifying the ankle-muscles co-contraction amplitude. Four different co-activations between GL and TA were observed during Heel strike (HS), Foot contact (FC), Push-off (PO), and Swing (SW), respectively. No differences were detected in time-duration of co-contractions detected in the different phases (p