Application of circular statistics in the study of muscular activity during semi-reclined cycling

Semi-reclined cycling is commonly recommended as a form of rehabilitation exercise; hence, a better knowledge of lower-extremity muscle activations is essential to improve the design of these exercise regimens. Techniques from circular statistics were used to investigate the effects of workload on the lower limb muscles´ onset and offset patterns during semi-reclined cycling. Fifteen healthy, male, novice cyclists participated in three cycling trials of different workloads with a constant cadence. Electromyography (EMG) data of four lower limb muscles and pedal´s kinematics were collected. By using circular statistics, we demonstrated that cycling workload does have an effect on the onset and offset of lower-extremity muscles during semi-reclined cycling, while using linear methods would result in incorrect implications. These findings suggest that circular statistics is a proper tool in analyzing muscular onset and offset in cycling.