Spine and pelvis coordination variability in rowers with and without chronic low back pain during rowing.
The aim of this study was to compare the spine-pelvis coordination and coordination variability (CV) during rowing in elite rowers with and without chronic low back pain (CLBP). Fourteen professional rowers (6 healthy and 8 with CLBP) participated in this study. 3D kinematic of upper trunk (UT), lower trunk (LT), lower back (LB), and pelvis segments during ergometer rowing at 70% and 100% of peak power were captured. The adjacent segments' coordination and CV were calculated using modified vector coding method. The results showed that segments' range of motion increased in both groups with increasing intensity, especially in CLBP rowers. CLBP rowers showed significantly lower: LT dominancy in LT/LB coordination at both intensities; anti-phase pattern in LB/Pelvis coordination at 100% intensity; UT/LT CV in early recovery, and significantly higher LB/Pelvis CV in final recovery and catch position (p < 0.05). Moreover, both groups showed significantly lower UT dominancy for UT/LT coordination in sagittal plane; higher anti-phase pattern in frontal plane; lower UT/LT CV in sagittal plane, lower LT/LB CV in sagittal and transverse plane, lower LB/Pelvis CV in frontal plane in trunk preparation phase, and a lower UT/LT CV in frontal plane for acceleration phase at 100% versus 70% intensity. In conclusion rowers with CLBP cannot adapt their coordination pattern and its variability with increase in intensity, and the movement in the kinematic chain from pelvis to UT stops in spine-pelvic junction. These findings have practical implications in designing coaching and rehabilitation strategies to facilitate performance and prevent injuries.