The Effects of an Ankle Destabilization Device on Muscular Activity while Walking

Abstract

Chronic Ankle Instability sprain causes are unclear and many factors or mechanisms may contribute to recurrence of this injury. The aim of the study was to investigate how an ankle destabilization device affects the EMG patterns of the ankle muscles during ankle stabilization against inversion. The left foot was equipped with a mechanical device mounted under the heel of the shoe. This mechanical device induces subtalar joint destabilization necessitating the control of ankle muscles. Surface electrodes were placed over the tibialis anterior, the peroneus longus, the peroneus brevis, the gastrocnemius lateral, and the gastrocnemius medial. Nine healthy subjects (mean age 37+/-12 yr; mean mass 68+/-17 kg; mean height 1.73+/-0.7 m) were instructed to walk normally along a tape fixed on the floor. The ankle destabilization device altered the walking pattern of all subjects. More specifically, the walking pattern is disturbed resulting in higher amplitude of the EMG activity of the peroneal muscles and the Tibialis Anterior and anticipatory reactions in the peroneal muscles. The results suggest that the ankle destabilization device could be beneficial for rehabilitation programs especially during the training of walking. Using this material may help to a specific reinforcement of muscles involved in anti-inversion ankle movement.

Lower Extremity Muscle Activation in Patients With or Without Chronic Ankle Instability During Walking

“…In addition, the largest variability was a 5% SD in peroneus longus activation in the healthy participants. 38 We estimated that 15 participants per group would be sufficient to find differences at an a level (type I error) of .05 and power (1-b) of 0.8. We performed an independent t test for each dependent variable to compare groups.…”

“…We performed an a priori sample-size estimate based on published data 38 showing a minimal change of 6% in lateral gastrocnemius activation during normal walking. In addition, the largest variability was a 5% SD in peroneus longus activation in the healthy participants.…”

Effects of 2 Ankle Destabilization Devices on Electromyography Measures During Functional Exercises in Individuals With Chronic Ankle Instability

“…For the purpose of this study, we operationally defined ankle destabilization devices as devices that can be worn like a boot or sandal and have an articulator beneath the calcaneus that mimics ankle motion around the Henke axis of the subtalar joint. 13,18,19 When using these devices, an individual is forced into inversion, internal rotation, and plantar flexion on IC during functional tasks. The anticipated perturbation that is caused by the device is thought to lead to activation of the evertor muscles prior to IC to prevent the foot from going into excessive inversion.…”

“…13,19 Unlike traditional rehabilitation tools, such as foam pads and wobble boards, which are commonly used to improve neuromuscular control, ankle destabilization devices are worn like shoes. For the purpose of this study, we operationally defined ankle destabilization devices as devices that can be worn like a boot or sandal and have an articulator beneath the calcaneus that mimics ankle motion around the Henke axis of the subtalar joint.…”

Effects of Long and Short Ankle Destabilization Devices on Muscular Activity while Walking

“…Accordingly, a device that induces a normal pattern of movements related to dynamic conditions such as walking should prove useful. Forestier et al exploited a kind of ankle destabilization device worn as shoes and suggested that the ankle destabilization device could be beneficial in rehabilitation programs, especially for the training of walking 10) . Following that research, we devised and fabricated two kinds of ankle destabilization device and evaluated the effect of the ankle destabilization devices on the ankle muscular activities observed while walking.…”