The impact of sagittal imbalance on walking in patients with lumbar spinal canal stenosis

Purpose: Gait and posture disorder severely impedes the quality of life of affected patients with lumbar spinal canal stenosis (LSCS). Despite the major health concern, there is a paucity of literature about the relationships among spatiotemporal gait parameters and spinal sagittal parameters. This is a cross sectional study performed in a single tertiary referral center to determine the relationships among spatiotemporal gait parameters and spinal sagittal parameters in patients with LSCS. Methods: A total of 164 consecutive patients with LSCS, 87 men and 77 women with mean age of 70.7 years, were enrolled. Spatiotemporal gait parameters were studied using a gait analysis system. Spinal sagittal parameters were studied including sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic inclination (PI), and pelvic tilt (PT) both in the neutral and stepped positions. Results: SVA was significantly larger in the stepped position than in the neutral position (neutral position, 72.5 mm; stepped position, 96.8 mm; p = 0.003). Parameters regarding the pelvis exhibited significant differences, which could represent pelvic anteversion in the stepped position. By stepwise multiple regression analysis, the prediction models, containing SVA (neutral) and PT (stepped) for double supporting phase, exhibited statistical significance, and accounted for approximately 50% of the variance. Conclusions: The present study provides statistically established evidence of correlation among spatiotemporal gait parameters and spinal sagittal parameters. Differences between sagittal parameters in neutral and stepped position may stand for the postural control during gait cycle, and increased SVA in neutral position and increased PT in stepped position may correlate with prolonged double supporting phase.

Kinematics Analysis on the Throwing Skills of Elite Chinese Male Hammer Athletes

Hammer throw is one of the traditional track and field events but it only has a short history in China. Chinese hammer athlete Shizhu Wang won the championship of China Long Throw Open in 2013, but the performance in the game has a big gap with the world record. In order to improve the techniques of Chinese men hammer athletes, have a clearly understanding of the rational factors and internal relations of hammer throw technique, enrich the theory of the action and provide reference to the hammer throw training, we made a 3D camera resolution on the top three men hammer throwers (Shizhu Wang, Dakai Qi and Xiwan Jiang) at the game site of China Long Throw Open in 2013, with the three-dimensional analysis we gained the kinematic parameters. We made a comparison on the parameters between Chinese and foreign elite men hammer throwers. The result shows that: Compared with the datas of outstanding foreign athletes, the pre-swing time is much larger and hammer velocity increment is much smaller in the pre-swing stage; the total rotation time is much longer, and the single to double supporting time is distributed unreasonly, what’s more, the change between the knee joint and bevel angle are too small; the shot speed ,with the fastest Shizhu Wang of 24.87 m/s, is much slower than that of foreign famous athlete Sedych (30.7 m /s), and longer hammer throw running time, which are the main reasons that affect athletes’ performance.