An electromyographic examination of the effects of load on human gait

The electromyographic patterns of six muscles of five subjects were recorded concomitantly with surface electrodes as they walked without load (control) and when they carried a load in one hand while walking. Gait was recorded by the means of footswitches. Integrated electromyography increased with both speed and load. The e.m.g. responses of the tibialis anterior and triceps surae muscles of the same side were equal in duration and potential at all velocities. At slow and normal walking speeds, e.m.g. action durations of tibialis anterior were longer on the contralateral than on the ipsilateral side of subjects when they carried a load in one hand, while the amplitude of e.m.g. action potential was augmented on the ipsilateral in relation to the contralateral. Stance time was longer on the ipsilateral leg, while swing time was longer on the contralateral leg.