Effects of body mass index on segment coordination and joint variability in running

Running is one of the most popular types of physical activity and can be optimised by increasing the movement patterns efficiency. Running biomechanics involves synchronous movements of the entire kinetic chain with a considerable inter-individual variability in lower limb kinematics and the influence of individuals characteristics. This chapter will explore how the body mass index influences the intersegmental coordination, evaluated by lower extremity joint amplitudes used to characterise the running technique. The approach to exploring the relative intersegmental coordination was carried by computing the continuous relative phase between two joint amplitudes. The joint movement variability (measured across the entire gait cycle during running) was accessed using approximate entropy. Results for lower limb relative angles variability showed that overweight individual presented moderate lower values mainly in both right and left knee angle. The results of continuous relative phase suggested that different body mass index affects the ankle-knee inter-joint coordination pattern during the swing phase and knee-hip during the stance phase, representing the 40% of the stride phase. This approach can facilitate the assessment and understand of lower extremity joint coupling during running and provide further insight into the role of joint coupling to improve running technique and develop prevention strategies to minimize injury risk.