The Study of Upper Extremity Strength in Sagittal Plane and its Application on Wheelchair Propulsion

• Main Authors: Chang-Dian Liu, 劉昌典
• Other Authors: Dengchuan Cai
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/40739850559599392511

碩士 === 國立雲林科技大學 === 工業設計系碩士班 === 101 === Literature has pointed that wheelchair performance ability is related to upper limb strength. Improvement of upper limb strength can be done by muscle training, another way is to determine the better range and orientation of exertion. This study focus on the strength that can be exerted at different positions on sagittal plane. A wheelchair design will be given based on the experiment result. Maximum isometric strength is tested. The posture is defined by sitting with the trunk upright, remaining the upper arm vertical and the forearm horizontal. Let the hand grip position as center point(CP), 33.3%, 66.7%, 100% forearm length as round, than get three concentric circles. The direction to which subjects look forward directly is defined as 0°. Around the CP, 0° 45°, 90°, 135°, 180°, 225°, 270° and 315° is defined in counterclockwise direction(right view of subjects). At each concentric circle, 8 points can be derived by using these angles. 3 length x 8 angles + 1 CP = 25 positions are defined in the sagittal area. Subjects are asked to pull, push, lift up and press down by using the handle at each position. The experimental result shows：(1) Gender, exertion orientation, angle and length all have significant influence on strength. The effect of angle become more obvious when the length increase. (2) Pulling strength is larger than other 3 orientations by both male and female at 0°, 45° and 315° (9 points). At CP, 90°33.3% and 135°33.3% (3 points), pulling is still the strongest orientation for female. But for male, pulling shows no difference with pushing or lifting at these 3 points. (3) Press down strength is larger than other 3 orientations at 90°100%, 135°100% for both male and female. (4) Lift up strength is greater than other 3 orientations at 180°66.7%, 180°100%, 225°66.7% and 225°100% (4 points) for male. For female, lift strength is greatest orientation at 225°100%, 225°100% and 270°100% (3 points).(5) Pulling can generate largest strength in all exertion orientations. (6) Duncan is used for grouping the pulling strength at different positions. Maximum strength group contains 0°, 45°, 315°100% (7 points). Sub-maximum strength group contains CP、90°33.3%、135°33.3%、315°33.3%、315°66.7% (5 points). The wheelchair design use the lever-propulsion prototype. Based on Result (5) and (6), this wheelchair is propelled by pulling. And the hand routing track pass through the maximum and sub-maximum pulling strength positions.