Muscle Activity Patterns of Lower Limb during Lateral (frontal) Side Stepping Task Modulation from Different Heights

Different muscle groups function in synchrony and coordination to perform a given task, wherein the activity of one muscle group closely affects that of another [1,3]. Osteoarthritis (OA), a chronic joint disease, is the most common musculoskeletal complaint worldwide characterized by pain, disability and progressive loss of function. It is associated with significant health and welfare costs [2,7]. The knee is the most frequently affected lower limb joint and prevalence of knee OA increases with age [6]. Several studies have shown that muscle recruitment patterns and neuromuscular efficiency are different for patients with OA compared to normal controls during simple closed chain activities [4,5]. However, no studies have investigated frontal plane control or the modulation of control due to, for example, a change in time or distance in OA [5,6]. This paper reports the results of a pilot study with healthy subjects to determine muscle activation patterns (electromyogram, EMG), and modulation of these patterns, in a frontal plane step initiation task.