Kloosterman Marieke G M, Eising Hilde, Schaake Leendert, Buurke Jaap H, Rietman Johan S
Roessingh Research and Development, Enschede, The Netherlands.
Clin Biomech (Bristol). 2012 Jun;27(5):428-35. doi: 10.1016/j.clinbiomech.2011.11.010. Epub 2011 Dec 29.
Repetitive forces and moments are among the work requirements of hand-rim wheelchair propulsion that are related to shoulder injuries. No previous research has been published about the influence of power-assisted wheelchair propulsion on these work requirements. The purpose of our study was therefore to determine the influence of power-assisted propulsion on shoulder biomechanics and muscle activation patterns. We also explored the theoretical framework for the effectiveness of power-assisted propulsion in preventing shoulder injuries by decreasing the work requirements of hand-rim wheelchair propulsion.
Nine non-wheelchair users propelled a hand-rim wheelchair on a treadmill at 0.9 m/s. Shoulder biomechanics, and muscle activation patterns, were compared between propulsion with and without power-assist.
Propulsion frequency did not differ significantly between the two conditions (Wilcoxon Signed Rank test/significance level/effect size:4/.314/-.34). During power-assisted propulsion we found significantly decreased maximum shoulder flexion and internal rotation angles (1/.015/-.81 and 0/.008/-.89) and decreased peak force on the rim (0/.008/-.89). This resulted in decreased shoulder flexion, adduction and internal rotation moments (2/.021/-.77; 0/.008/-.89 and 1/.011/-.85) and decreased forces at the shoulder in the posterior, superior and lateral directions (2/.021/-.77; 2/.008/-.89 and 2/.024/-.75). Muscle activation in the pectoralis major, posterior deltoid and triceps brachii was also decreased (2/.038/-.69; 1/.015/-.81 and 1/.021/-.77).
Power-assist influenced the work requirements of hand-rim wheelchair propulsion by healthy subjects. It was primarily the kinetics at rim and shoulder which were influenced by power-assisted propulsion. Additional research with actual hand-rim wheelchair users is required before extrapolation to routine clinical practice.
重复的力和力矩是手轮式轮椅推进工作要求的一部分，与肩部损伤有关。此前尚无关于电动助力轮椅推进对这些工作要求影响的研究发表。因此，我们研究的目的是确定电动助力推进对肩部生物力学和肌肉激活模式的影响。我们还探讨了电动助力推进通过降低手轮式轮椅推进的工作要求来预防肩部损伤有效性的理论框架。
九名非轮椅使用者在跑步机上以0.9米/秒的速度推动手轮式轮椅。比较了有无电动助力推进时的肩部生物力学和肌肉激活模式。
两种情况下的推进频率无显著差异（威尔科克森符号秩检验/显著性水平/效应量：4/.314/-.34）。在电动助力推进过程中，我们发现最大肩部前屈和内旋角度显著减小（1/.015/-.81和0/.008/-.89），轮缘上的峰值力减小（0/.008/-.89）。这导致肩部前屈、内收和内旋力矩减小（2/.021/-.77；0/.008/-.89和1/.011/-.85），以及肩部在后方、上方和外侧方向的力减小（2/.021/-.77；2/.008/-.89和2/.024/-.75）。胸大肌、三角肌后束和肱三头肌的肌肉激活也有所降低（2/.038/-.69；1/.015/-.81和1/.021/-.77）。
电动助力影响了健康受试者手轮式轮椅推进的工作要求。主要是轮缘和肩部的动力学受到电动助力推进的影响。在推广至常规临床实践之前，需要对实际的手轮式轮椅使用者进行更多研究。
