The Function of the Muscles of the Lower Leg in Relation to Movements of the Tarsus

Peroneus longus and tibialis anterior muscle activity in the stance phase: A quantified electromyographic study of 10 controls and 25 patients with chronic ankle instability

“…Movement of the foot in the first part of the walking cycle is accompanied by major peak activity of the tibialis anterior. The tibialis anterior contracts eccentrically and acts together with other weight-accepting muscles, absorbing the shock and breaking the slight plantar flexion and pronation of the foot (Milner et al 1971, Ambagtsheer 1978, Nilsson et al 1985, Ericson et al 1986, Winter and Yack 1987. In our study, the main very regular peak of tibialis anterior activity during stance was also found to occur in the first quarter of stance.…”

“…Activity of the tibialis anterior in midstance has received little attention. The activity varies and is believed to stabilize the tarsus (Ambagtsheer 1978). A slight shift in activity to the second quarter of stance when subjects have to maintain balance suggests that this muscle works actively for balance control, although no increase of the total amount of activity was found.…”

“…There is controversy as to whether the peroneal muscles are active at the time of heel contact (Click et al 1976, van Linge 1988. Ambagtsheer (1978) found activity of the peroneus longus in 2 of 11 subjects before heel contact, but described no further activity of this muscle until footflat. Winter and Yack (1987) found an initial peak of the peroneus longus at foot-flat to control inversion.…”

“…He demonstrated that the activity of the tibialis posterior and peroneus longus alternate in relation to the amplitude of the lateral component of the ground reaction force and take part in controlling balance. Ambagtsheer (1978) occasionally found the same alternation, but thought it improbable that this was to maintain balance.…”

“…EMG activity of the peroneus longus in gait has seldom been recorded and, when examined, the function of the peroneus longus is related to stabilization of the foot and to acceleration about the moment of push-off (Sutherland 1966, Ambagtsheer 1978, Winter and Yack 1987.…”