Dallmeijer A J, van der Woude L H, Veeger H E, Hollander A P
Institute for Fundamental and Clinical Human Movement Sciences, Faculty of Human Movement Sciences, Vrije Universiteit Amsterdam, The Netherlands.
Am J Phys Med Rehabil. 1998 May-Jun;77(3):213-21. doi: 10.1097/00002060-199805000-00006.
The objective of this study was to investigate effectiveness of force application, the ratio power output/energy expenditure, and timing parameters of wheelchair propulsion in persons with tetraplegia (TP, n=17) and paraplegia (PP, n=12), at two different intensity conditions. All subjects performed a maximal exercise test on a wheelchair ergometer. Exercise bouts with an intensity of 30 to 50% and 60 to 80% of the maximal power output were analyzed. Effectiveness of force application, defined as the ratio of the effective force and the total force, was considerably lower in TP, compared with PP. Effectiveness of force application in the plane of the wheel was comparable between TP and PP. TP showed a significantly lower effectiveness of force application in the frontal plane and applied the forces in a more lateromedial direction to the hand rim. The ratio power output/energy expenditure, calculated as an indication of gross mechanical efficiency, was considerably lower in TP and was associated with the effectiveness of force application (r=0.64; P < 0.01). Timing parameters showed that TP positioned their hands in a more backward position on the hand rim. Comparing the different intensity conditions revealed that force was applied more effectively, and the ratio power output/energy expenditure was higher at the higher intensity condition. Push time, relative to cycle time, increased, and beginning angle showed a forward shift with a higher load. TP tended to decrease, whereas PP showed a tendency for an increase in stroke angle with a higher load. The low effectiveness and different pattern of force application in TP should be taken into account when developing other wheelchair propelling mechanisms and training programs for this population.
本研究的目的是调查在两种不同强度条件下，四肢瘫痪者（TP，n = 17）和截瘫者（PP，n = 12）轮椅推进时的力施加效果、功率输出/能量消耗比以及时间参数。所有受试者在轮椅测力计上进行了最大运动测试。分析了强度为最大输出功率30%至50%和60%至80%的运动回合。力施加效果定义为有效力与总力之比，与PP相比，TP的力施加效果显著更低。TP和PP在轮平面内的力施加效果相当。TP在额平面内的力施加效果显著更低，且向手轮缘施加力的方向更偏向内外侧。作为总体机械效率指标计算的功率输出/能量消耗比，TP显著更低，且与力施加效果相关（r = 0.64；P < 0.01）。时间参数显示，TP将手放置在手轮缘上更靠后的位置。比较不同强度条件发现，在较高强度条件下，力的施加更有效，功率输出/能量消耗比更高。相对于周期时间，推的时间增加，起始角度随着负荷增加向前偏移。负荷增加时，TP的冲程角度倾向于减小，而PP的冲程角度有增加的趋势。在为该人群开发其他轮椅推进机制和训练计划时，应考虑TP力施加效果低和力施加模式不同的情况。
