Changes in drive phase lower limb kinematics during a 60 min cycling time trial

Abstract

ObjectivesThe aim of this study was to evaluate changes in the three dimensional lower limb kinematics during a simulated cycling time trial. DesignRepeated measures. MethodsTen experienced male road cyclists performed a 60min cycling test at a workload based on previous onset of blood lactate accumulation (OBLA) testing. The time trial (TT) was divided into six 10min periods consisting of 8min cycling at steady state (88% of OBLA) followed by a 90s effort phase (140% of OBLA) and a 30s recovery phase (60% of OBLA). Three-dimensional kinematic data (200Hz) were recorded in the last minute of each steady state phase with specific attention directed at changes in range of motion (ROM) and consistency of orientation at the hip, knee and ankle joints during drive phase. Resultsfrom repeated measures ANOVA indicated a mean effect for test duration on the drive phase ROM in both hip extension (p=0.027) and ankle dorsi flexion (p<0.001). The SD of the mean tibial rotation during the drive phase was the only measure of movement consistency that showed an effect for test duration (p=0.031). ConclusionsThese findings indicated that participants tended to increase the ROM in hip extension and ankle flexion during drive phase at the end of a TT. Changes in the consistency of tibial rotation during the drive phase may be an important indicator of fatigue and should be monitored by coaches during training due to its possible relationship with injury and fatigue.