Warren C G, Ko M, Smith C, Imre J V
Arch Phys Med Rehabil. 1982 Sep;63(9):447-9.
The powered reclining wheelchair used by quadriplegic and other severely disabled people was studied to determine how the chair could be modified so that repeated recline would not produce shear forces that tend to cause the user to be relocated in the chair, limiting independent functioning. Three modifications of the chair were studied: a freely sliding back, a commercially available powered sliding seat, and 4-bar linkage to hinge the chair back. A counterbalanced, freely sliding back was constructed for testing and was instrumented to measure displacement of the person in the chair during recline. The curves of back displacement vs angle or recline were determined for a sample or 8 quadriplegic subjects. The sliding back mechanism was determined to be impractical for incorporation into current chair designs since it required a heavy, rigid back frame. The sliding seat was found to have limited value since it only slightly decreased the back motion during recline. However, the 4-bar linkage virtually eliminated relative motion between the person's back and the chair back, providing a mechanism for potentially resolving this problem both in new recliner design and for retrofit to existing reclining wheelchairs.
对四肢瘫痪者及其他重度残疾人使用的电动躺椅进行了研究，以确定如何对该躺椅进行改进，使反复躺卧不会产生剪切力，这种剪切力往往会导致使用者在椅子上移位，从而限制其独立功能。研究了躺椅的三种改进方式：可自由滑动的椅背、市售的电动滑动座椅以及用于铰接椅背的四连杆机构。制作了一个带有平衡装置、可自由滑动的椅背用于测试，并安装了仪器以测量躺卧过程中椅上人员的位移。针对8名四肢瘫痪受试者的样本，确定了椅背位移与躺卧角度的曲线。由于需要一个沉重、刚性的椅背框架，滑动椅背机构被认为不适合应用于当前的椅子设计中。发现滑动座椅的作用有限，因为它在躺卧时仅略微减少了椅背的移动。然而，四连杆机构几乎消除了人体背部与椅背之间的相对运动，为在新的躺椅设计以及对现有电动躺椅进行改造时潜在解决这一问题提供了一种机制。
