Influence of Chronic Ankle Instability on Human Movement: a Three Dimensional Kinematic and Electromyographic Analysis

Abstract

Context: Lateral ankle sprains are one of the most common musculoskeletal injuries in the general and sporting population and as such present high-cost implications and time lost to sport and employment. Following an initial lateral ankle sprain, a high percentage of people develop chronic ankle instability with symptoms such as reduced range of motion, strength and proprioceptive deficits, episodes of giving way and instances of re-injury. Research investigating full body with multi-segmental foot kinematics and electromyography is limited thus impacting the development of successful rehabilitation and injury prevention strategies. Aim: The purpose of this research was to perform exploratory kinematic and surface electromyographic (sEMG) data analysis of the trunk, hip, knee, forefoot-tibia, forefoot-hindfoot and hindfoot-tibia between individuals with chronic ankle instability and healthy controls during walking, landing and cutting, three movements commonly associated with lateral ankle sprains Participants: Eighteen (14 males, 4 females) healthy controls (age 22.4 ± 3.6 years, height 177.8 ± 7.6 cm, mass 70.4 ± 11.9 kg) and 18 (13 males, 5 females) participants with chronic ankle instability (age 22.0 ± 2.7 years, height 176.8 ± 7.9 cm, mass 74.1 ± 9.6 kg). Participants’ data were split into the healthy control and chronic ankle instability groups based on the results of the Identification of Functional Ankle Instability questionnaire. Methods: Participants were tested during walking (Chapter 6.0), single leg landing (Chapter 7.0) and cutting (Chapter 8.0). Three-dimensional kinematics were collected using the combined Helen Hayes and Oxford Foot Model and sEMG recorded for the peroneus longus, tibialis anterior and gluteus medius. Statistical parametric mapping, discrete variable analysis and regression analysis were subsequently performed. Results: Significantly modified kinematics were observed in each of the movements performed in the chronic ankle instability group. Decreased forefoot-tibia internal rotation angular displacement was found to occur prior to initial contact in all three of the observed movements when comparing the affected limb to the healthy matched control prior to initial contact. Significantly modified electromyography was observed in the chronic ankle instability group during the cutting manoeuvre but not during the walking and landing manoeuvre. Conclusions: Key differences have been observed between groups specific to movements but also across movements. These differences are identified in not just foot and ankle kinematics but also higher up the kinetic chain in the knee, hip and trunk. Decreased forefoot-tibia internal rotation may be a variable of interest for future research due to its presence in each of the observed movements. Differences are also highlighted in the contralateral limb of the chronic ankle instability. These findings may therefore be used in the development of injury prevention and rehabilitation programmes and in the development of screening strategies. This could help to aid in the reduction in incidence of chronic ankle instability and improve the quality of life for those with chronic ankle instability.