Kinematic Asymmetries of the Lower Limbs during Ergometer Rowing

Abstract

Rowing injuries, particularly of the lumbar spine, are often attributed to poor technique. Rowing technique comprises a series of coordinated movements between the back, upper limbs, and lower limbs, and abnormalities in these may lead to injury. The aim of this study was to test the hypothesis that ergometer rowing is symmetrical with respect to lower limb motion and that deviations from symmetry result from rowing experience, work rate, or stroke position. Twenty-two rowers in three levels of ability participated in this study. A motion analysis system was used with an instrumented rowing ergometer, which incorporated load cells at the handle and seat. Kinematic measurements of the knees, hips, lumbar-pelvic joints, and pelvic twist, in addition to measures of handle force, seat force, stroke length, mediolateral seat drift, and mean external power, were made during an incremental step test. Elite rowers exhibited the largest handle force and mean external power (P < 0.01) and least mediolateral seat drift (P < 0.01). All groups demonstrated lower limb asymmetries, with hip asymmetries significantly greater than knee asymmetries (P < 0.01). Regression analysis indicated that both hip and knee range of motion (ROM) asymmetry was significant (P < 0.05) in predicting lumbar-pelvic flexion at the catch and maximum handle force of the stroke. However, hip ROM asymmetry showed a better relation with lumbar-pelvic flexion compared with knee ROM asymmetry, explaining a greater proportion of the variance. Bilateral asymmetries during the rowing stroke, particularly at the hips, can contribute to suboptimal kinematics of the lumbar-pelvic region. Quantification of hip ROM asymmetries may therefore be a useful tool in predicting the development of low back pain in rowers.