Thorax and pelvis kinematics change during sustained cycling.

The aim of this study was to evaluate time dependent changes in 3 dimensional (3D) thorax and pelvis kinematics during an intense 60 min bike ride. 10 experienced male road cyclists pedalled for 60 min at workloads based on previous onset of blood lactate accumulation (OBLA) testing. The 60 min cycle was divided into six 10 min periods consisting of 8 min of steady state cycling (88% of OBLA) followed by 90 s at 140% of OBLA and a 30 s recovery phase (60% of OBLA). Thorax and pelvis kinematic data were recorded from 20 consecutive pedal revolutions using a 3D motion capture system (200 Hz) during each steady state phase. Repeated measures ANOVA with Bonferroni corrections were used to test for effects of test duration on segmental kinematics. Results indicated an effect for test duration on the mean thorax (p<0.001) and pelvic tilt (p=0.042), pelvic lateral tilt velocity (p=0.006) and the ROM in thoracic lateral tilt (p<0.001). These changes all occurred between the 4th and 5th work periods. Findings indicated that during the latter stages of a high intensity ride cyclists changed the sagittal plane thorax and pelvis orientation, increased lateral thoracic movements and pelvic lateral tilt velocities. © Georg Thieme Verlag KG Stuttgart · New York.