This is an experimental work aimed et evaluating the electromyografic activity of selected muscles with and without load on the treadmill and co-current assessment of the impact of asymmetric load on lateral weight distribution. The reaserch was conducted on 6 recreational runners, and the load was placed on the periphery of the right upper extremity.
The following muscle groups were recorded by surface electromyography: m.deltroideus pars anterior, m.trapezius pars ascendent et descendent, paravertebral lumbar muscles, m.gastrocnemius lateralis and m.tibialis anterior. All probands demonstrated decline in the average amplitude of the normalized EMG signal at left-sided m.gastrocnemius lateralis.
The reduced level of activity of this muscle is most probably expression of compensatory mechanism of the body, which is needed to maintain the same stride length and height of the center of gravity during the flight phase of the stride.