Maly Monica R, Culham Elsie G, Costigan Patrick A
Faculty of Health Sciences, School of Rehabilitation Therapy, Queen's University, Kingston, Ont., Canada.
Clin Biomech (Bristol). 2002 Oct;17(8):603-10. doi: 10.1016/s0268-0033(02)00073-6.
Gait biomechanics (knee adduction moment, center of pressure) and static alignment were investigated to determine the mechanical effect of foot orthoses in people with medial compartment knee osteoarthritis.
Repeated measures design in which subjects were exposed to three conditions (normal footwear, heel wedge and orthosis) in random order.
The knee adduction moment is an indirect measure of medial compartment loading. It was hypothesized that the use of a 5 degrees valgus wedge and 5 degrees valgus modified orthosis would shift the center of pressure laterally during walking, thereby decreasing the adduction moment arm and the adduction moment.
Peak knee adduction moment and center of pressure excursion were obtained in nine subjects with medial compartment knee OA during level walking using an optoelectric system and force plate. Static radiographs were taken in 12 subjects using precision radiographs.
There was no difference between conditions in static alignment, the peak adduction moment or excursion of the center of pressure in the medial-lateral direction. No relationship was found between the adduction moment and center of pressure excursion in the medial-lateral plane. The displacement of the center of pressure in the anterior-posterior direction, measured relative to the laboratory coordinate system, was decreased with the orthosis compared to the control condition (P=0.036) and this measure was correlated with the adduction moment (r=0.45, P=0.019).
The proposed mechanism was not supported by the findings. The reduction in the center of pressure excursion in the anterior-posterior direction suggests that foot positioning was altered, possibly to a toe-out position, while subjects wore the orthoses. Based on the current findings, we hypothesize that toe-out positioning may reduce medial joint load.
Knee Osteoarthritis is the most common cause of chronic disability amongst seniors. Developing inexpensive, non-invasive treatment strategies for this large population has potential to impact health care costs, quality of life and clinical outcomes.
研究步态生物力学（膝关节内收力矩、压力中心）和静态对线情况，以确定足部矫形器对内侧间室膝关节骨关节炎患者的力学影响。
重复测量设计，受试者按随机顺序接受三种条件（普通鞋、足跟楔形垫和矫形器）。
膝关节内收力矩是内侧间室负荷的间接测量指标。据推测，使用5度外翻楔形垫和5度外翻改良矫形器会在行走过程中将压力中心向外侧移动，从而减小内收力矩臂和内收力矩。
使用光电系统和测力板，在9名内侧间室膝关节骨关节炎患者平走时获取膝关节内收力矩峰值和压力中心偏移量。对12名受试者拍摄精确的静态X线片。
静态对线、内收力矩峰值或压力中心在内侧-外侧方向的偏移量在不同条件之间无差异。在内侧-外侧平面内，未发现内收力矩与压力中心偏移量之间存在关联。与对照条件相比，使用矫形器时，相对于实验室坐标系测量的压力中心在前后方向的位移减小（P = 0.036），且该测量值与内收力矩相关（r = 0.45，P = 0.019）。
研究结果不支持所提出的机制。压力中心在前后方向偏移量的减少表明，受试者佩戴矫形器时足部位置发生了改变，可能变为足尖外旋位。基于当前研究结果，我们推测足尖外旋位可能会减轻内侧关节负荷。
膝关节骨关节炎是老年人慢性残疾的最常见原因。为这一庞大群体开发廉价、无创的治疗策略有可能影响医疗保健成本、生活质量和临床结局。
