Slowik Jonathan S, Requejo Philip S, Mulroy Sara J, Neptune Richard R
Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, USA.
Pathokinesiology Laboratory, Rancho Los Amigos National Rehabilitation Center, Downey, CA, USA; Rehabilitation Engineering, Rancho Los Amigos National Rehabilitation Center, Downey, CA, USA.
J Biomech. 2016 Jun 14;49(9):1554-1561. doi: 10.1016/j.jbiomech.2016.03.031. Epub 2016 Mar 25.
The hand pattern (i.e., full-cycle hand path) used during manual wheelchair propulsion is frequently classified as one of four distinct hand pattern types: arc, single loop, double loop or semicircular. Current clinical guidelines recommend the use of the semicircular pattern, which is based on advantageous levels of broad biomechanical metrics implicitly related to the demand placed on the upper extremity (e.g., lower cadence). However, an understanding of the influence of hand pattern on specific measures of upper extremity muscle demand (e.g., muscle power and stress) is needed to help make such recommendations, but these quantities are difficult and impractical to measure experimentally. The purpose of this study was to use musculoskeletal modeling and forward dynamics simulations to investigate the influence of the hand pattern used on specific measures of upper extremity muscle demand. The simulation results suggest that the double loop and semicircular patterns produce the most favorable levels of overall muscle stress and total muscle power. The double loop pattern had the lowest full-cycle and recovery-phase upper extremity demand but required high levels of muscle power during the relatively short contact phase. The semicircular pattern had the second-lowest full-cycle levels of overall muscle stress and total muscle power, and demand was more evenly distributed between the contact and recovery phases. These results suggest that in order to decrease upper extremity demand, manual wheelchair users should consider using either the double loop or semicircular pattern when propelling their wheelchairs at a self-selected speed on level ground.
手动轮椅推进过程中使用的手部模式（即完整周期的手部路径）通常被归类为四种不同手部模式类型之一：弧形、单环、双环或半圆形。当前的临床指南推荐使用半圆形模式，这是基于与上肢所承受需求隐含相关的广泛生物力学指标的有利水平（例如，较低的踏频）。然而，为了做出此类推荐，需要了解手部模式对上肢肌肉需求的特定指标（例如，肌肉力量和压力）的影响，但这些量在实验中很难测量且不切实际。本研究的目的是使用肌肉骨骼建模和正向动力学模拟来研究所使用的手部模式对上肢肌肉需求特定指标的影响。模拟结果表明，双环和半圆形模式产生的整体肌肉压力和总肌肉力量水平最为有利。双环模式在完整周期和恢复阶段的上肢需求最低，但在相对较短的接触阶段需要高水平的肌肉力量。半圆形模式的整体肌肉压力和总肌肉力量的完整周期水平第二低，且需求在接触阶段和恢复阶段之间分布更为均匀。这些结果表明，为了降低上肢需求，手动轮椅使用者在平地上以自行选择的速度推动轮椅时应考虑使用双环或半圆形模式。
