BIOMECHANICS OF THE UE IN WHEELCHAIR PROPULSION

描述（改编自研究者摘要）：多达120万 美国人依靠轮椅行动，这个数字正在增加。甚至 虽然上肢（UE）肌肉骨骼问题在 轮椅使用者，轮椅生物力学的科学文献 推进力有限。尤其是上肢和 负荷和肌肉骨骼损伤的风险知之甚少。一个系统 对轮椅使用者上肢的负荷进行评估 大大提高了我们的认识、治疗和预防能力， 肌肉骨骼损伤。在这项研究中， 将使用他们开发和验证的实验技术， 结合轮椅推进的分析模型， 已经开发。这种组合将使他们能够预测最大的 对于给定的轮椅配置，绕轮轴的推进力矩为 受试者的人体测量尺寸和力量能力的函数， 肩肘腕关节 在这项研究中，研究人员建议检查座位的影响， 位置和扶手直径对轮椅推进力学的影响。在 特别是，将使用三种衡量轮椅推进效率的方法。 这些措施包括轮椅推进强度比、 分数有效力（FEF），以及围绕 轮轴（Mw）。这些数量中的每一个都具有潜在的重要性，并且将被 当受试者在水平地面上推动轮椅并以12：1的速度向上时（跑： 上升）斜坡，以解决以下具体目标和假设： 假设1 -座椅高度将是“最佳的”（即，最小WPSR FEF和Mw）（180度=全肘 手的上止点，（如 与100度和140度的角度形成对比。） 假设2 -轴的中性位置（最大轴前方2.5cm） 最后位置）将比最后位置或最后位置更理想。 前部位置（即，最小WPSR;最大FEF和Mw）。 假设3 -轴处于空档位置，座椅提供 最佳的肘关节角度，中等直径（40厘米）的手柄将是更好的选择 与较小（28 cm）和较大（51 cm）的轮缘直径（即，最小 WPSR;最大FEF和Mw）。

DESCRIPTION (adapted from Investigator's abstract): As many as 1.2 million Americans rely on wheelchairs for mobility, and this number is increasing. Even though upper extremity (UE) musculoskeletal problems are common among wheelchair users, the scientific literature on the biomechanics of wheelchair propulsion is limited. In particular, the relationship between upper extremity loads and the risk of musculoskeletal injury is poorly understood. A systematic evaluation of the loads on the upper extremities of wheelchair users will do much to improve our understanding, treatment and ability to prevent musculoskeletal injuries in this population. In this study the investigators will use experimental techniques that they have developed and validated in conjunction with an analytical model of wheelchair propulsion that they have already developed. This combination will allow them to predict the maximum propulsion moment about the wheel axle for a given wheelchair configuration as a function of a subject's anthropometric dimensions and strength capacities at the shoulder, elbow, and wrist joints. In this study, the investigators propose to examine the effects of seat position and handrim diameter on the mechanics of wheelchair propulsion. In particular, three measures of wheelchair propulsion effectiveness will be used. These measures include the wheelchair propulsion strength ratio (WPSR), the fraction effective force (FEF), and the propulsion moment generated about the wheel axle (Mw). Each of these quantities has potential importance and will be analyzed while subjects propel a wheelchair on level ground and up a 12:1 (run: rise) ramp to address the following specific aims and hypotheses: Hypotheses 1 - The seat height will be "optimal" (i.e., minimum WPSR; maximum FEF and Mw) when the elbow angle is 120 degrees (180 degrees=full elbow extension) with the hands is at the top-dead center of the handrim, (as contrasted to angles of 100 degrees and 140 degrees.) Hypothesis 2 - The neutral position of the axle (2.5cm forward of the most extreme posterior position) will be more optimal that the most posterior or anterior positions (i.e., minimum WPSR; maximum FEF and Mw). Hypothesis 3 - With the axle in the neutral position and the seat providing the optimal elbow angle, a medium handrim diameter (40cm) will be a better choice as compared to smaller (28cm) and larger (51cm) rim diameters (i.e., minimum WPSR; maximum FEF and Mw).