Ankle instability caused by prolonged peroneal reaction time

Abstract

The reaction of 15 functionally unstable ankles to sudden inversion was described by monitoring muscle activity, joint motion, and alternation of the body center of pressure. The results were compared with those of 15 stable controls. Stable and unstable subjects showed a similar reaction pattern to sudden inversion: first, a peripheral reflex action, namely, a contraction of the peronei counteracting the ankle inverting momentum, and, then, a centrally elicited pattern, namely, a flexion of the hip, knee, and ankle relieving the vertical pressure on the ankle and producing ankle eversion. Unstable subjects did not show a defect in their central processing of afferent input. In contrast, a prolonged reaction time (median 84 msec compared with 69 msec in stable subjects) suggested a partial deafferentation of the reflex stabilization of the ankle and substantiated the theory of a proprioceptive deficit being responsible for ankle instability.

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

“…Freeman et al (1965) first suggested proprioceptive deficit because of tom ligaments and capsule as a possible cause of functional instability. The finding of a prolonged peroneal reaction time and increased postural sway seems to substantiate this theory (Tropp 1985, Karlsson 1989, Konradsen and Ravn 1990. Peroneal muscle weakness (Bosien et al 1955, Tropp 1985 after immobilization of the muscle or due to overstretching of the peroneal nerves at the time of inversion trauma have been described (Hyslop 1941, Nitz et al 1985.…”

“…Numerous factors, such as proprioceptive deficit, prolonged peroneal reaction time, increased postural sway, weakness of the peroneal muscles and damage to the peroneal nerves, have been related to functional instability of the ankle/foot (Hyslop 1941, Bosien et al 1955, Freeman et al 1965, Nitz et al 1985, Tropp 1985, Karlsson 1989, Konradsen and Ravn 1990). Whether these factors result in changes in the activity of the peroneal muscles during walking is still unknown.…”

Effects of Kinesio Tape Compared With Nonelastic Sports Tape and the Untaped Ankle During a Sudden Inversion Perturbation in Male Athletes

“…The time from perturbation to peak EMG did not differ between groups, as previous studies comparing muscle reaction time of stable and unstable ankles during no-tape conditions have shown, 4,5,41 although other studies have shown results to the contrary. 15,20 Neither elastic nor nonelastic tape had an overall effect on time to peak EMG; however, the condition-by-group interaction was close to being statistically significant. When analyzing these data, the highly variable nature of the EMG signal has led some authors to accept an alpha level of .1, in an effort to avoid a type II error.…”

Force sense deficits in functionally unstable ankles

“…The time interval between perturbation and a response that produces joint movement, and thus stability to the joint, is too slow to protect the unstable joint. [21][22][23] Because the feedback mechanism is too slow, any stability provided by muscles must be preset via a feed-forward mechanism. We suspect that an important variable that must be preset is muscle tension.…”