This study aimed to identify the effects of cycling posture, specifically the road and time-trial postures, on lower limb muscle activation patterns while pedalling submaximally. Nine recreationally active cyclists completed a 4-minute steadystate cycling trial in both postures, while surface electromyography (EMG) sensors recorded signals from six of the muscles in the lower leg: the vastus lateralis, rectus mfemoris, vastus medialis, biceps femoris, lateral gastrocnemius, and medial gastrocnemius. Three-dimensional kinematics recorded each complete pedal revolution. EMG signals were normalised to maximal voluntary isometric contractions (% of MVIC) and analysed across the full pedal cycle. A repeated measures ANOVA observed no significant differences in muscle activity between the postures or in any muscle (all p > 0.05). Results suggested that muscle activation under steady-state circumstances stays constant, despite postural changes affecting the biarticular and monoarticular muscles. This is likely because of coordinated effort distribution across whole muscle groups, particularly the quadriceps, which allows the cyclist to share the workload between muscles without changing activation levels. Findings also suggested that posture-related performance differences may be due to cardiorespiratory restrictions, highlighting the need to employ posture-specific training which addresses cardiovascular and respiratory roles. This study has provided insight for cyclists and coaches by highlighting that posture does not significantly impact lower-limb muscle activation, which allows for the pursuit of aerodynamic efficiency (mainly in the time-trial posture), without muscle activity being compromised. Future research should address whole muscle groups to better understand how effort distribution and compensatory strategies maintain constant activation levels, despite changes in posture.
PLEASE NOTE: You must be a member of the University of Lincoln to be able to view this dissertation. Please log in here.