两种不同矫形器对早期内侧间室膝关节骨性关节炎步态的影响

摘要 目的: 比较早期内侧间室膝关节骨性关节炎（OA）患者在佩戴膝关节外翻矫形器与外侧楔形角矫形鞋垫后所产生的下肢生物力学变化及差异,探讨不同矫形器在早期内侧间室膝关节骨性关节炎患者康复中的应用价值。 方法: 采用Vicon三维步态分析系统及Kislter测力台分别测评32例早期内侧间室型膝关节骨性关节炎患者在佩戴定制外侧楔形角矫形鞋垫（倾斜角5°）、膝关节外翻矫形器及无佩戴任何矫形器（测试期间均穿标准鞋）三种条件下的下肢关节运动学、动力学及时间空间参数。 结果: 相较于未佩戴任何矫形器情况,佩戴2种矫形器后膝关节内侧间室压力（膝关节内翻力矩,膝关节内翻角冲量）均明显降低（P<0.05）,此外佩戴外侧楔形角矫形鞋垫后患者踝关节外翻角度明显增加,足底压力中心明显向外侧偏移（P<0.05）。 结论: 两种不同的矫形器均有助于降低早期内侧间室型膝关节骨性关节炎患者在步行过程中膝内侧间室所产生的压力,两者治疗效果未见明显差异。     

内侧间室膝骨性关节的下肢关节生物力学变化

目的：了解内侧间室膝骨性关节炎患者与正常人群在行走过程中的下肢生物力学参数的差异,以便准确客观的对患者下肢功能进行评定。方法：通过三维步态分析系统和测力板分别对正常人群（正常组）25例和内侧间室膝骨性关节炎患者（患病组）25例进行时间空间以及髋、膝、踝关节的运动学和动力学参数采集,并进行比较。结果：与正常组比较,患病组在行走过程中的最大膝关节曲,踝关节跖/背屈,髋关节曲/伸角度以及关节活动范围均明显降低,髋关节内收力矩明显减小,膝关节内收力矩明显增加（均P〈0.05）。结论：内侧间室膝骨性关节炎患者下肢关节生物力学发生变化,步行过程中的膝关节所受的压力明显高于正常人群,为其康复评定及治疗提供客观评价依据。     

佩带膝外翻支具膝骨关节炎患者膝关节的生物力学变化

背景:佩带膝关节外翻矫形器已被证明是一种可以有效减轻内侧间室膝骨关节炎患者疼痛的方法,但是佩带矫形器后的膝关节所产生的运动学以及动力学变化至今尚不明确。目的:观察内侧间室膝骨关节炎患者佩带膝关节矫形器前后的膝关节运动学以及动力学参数变化,便于为将来设计新型膝关节矫形器提供依据。方法:纳入20例内侧间室膝骨关节炎患者,分别通过三维步态分析系统和测力板对其在佩带膝外翻矫形器及不佩带膝外翻矫形器两种情况步行中的运动学及动力学参数进行采集,并进行对比。结果与结论:相比未佩带膝关节外翻支具,佩带膝关节外翻支具后患者在步行过程中膝关节内收力矩明显减小,与此同时膝关节内翻角度明显减小,外翻角度明显增加(P均<0.05),膝关节在步行过程中的最大屈曲角度以及时间空间参数差异无显著性意义。提示膝关节外翻矫形器可有效地通过增加内侧间室膝骨关节炎患者膝关节在步行过程中的外翻角度减小内翻角度从而降低膝内侧间室所承受的压力,与此同时纠正膝关节非正常对线。     

佩带膝外翻支具膝骨关节炎患者膝关节的生物力学变化

背景：佩带膝关节外翻矫形器已被证明是一种可以有效减轻内侧间室膝骨关节炎患者疼痛的方法,但是佩带矫形器后的膝关节所产生的运动学以及动力学变化至今尚不明确。目的：观察内侧间室膝骨关节炎患者佩带膝关节矫形器前后的膝关节运动学以及动力学参数变化,便于为将来设计新型膝关节矫形器提供依据。方法：纳入20例内侧间室膝骨关节炎患者,分别通过三维步态分析系统和测力板对其在佩带膝外翻矫形器及不佩带膝外翻矫形器两种情况步行中的运动学及动力学参数进行采集,并进行对比。结果与结论：相比未佩带膝关节外翻支具,佩带膝关节外翻支具后患者在步行过程中膝关节内收力矩明显减小,与此同时膝关节内翻角度明显减小,外翻角度明显增加（P均〈0.05）,膝关节在步行过程中的最大屈曲角度以及时间空间参数差异无显著性意义。提示膝关节外翻矫形器可有效地通过增加内侧间室膝骨关节炎患者膝关节在步行过程中的外翻角度减小内翻角度从而降低膝内侧间室所承受的压力,与此同时纠正膝关节非正常对线。     

下肢全长负重位X线检查在膝关节炎内外翻畸形中的临床价值

目的:探讨膝关节炎患者下肢全长负重位X线片对膝内、外翻畸形诊断的临床价值。方法:选取32例临床诊断为膝关节炎51膝分别拍摄下肢全长负重X线片,测量下肢力线和机械轴偏距(mechanical axis offset distance,MAD),解剖学股胫骨角(anatomical femor-tibial angle,aFTA),股骨远端力学外侧角(mechanical lateral distal femoral angle,mLDFA),胫骨近端力学内侧角(mechanical medial proximal tibial angle,mMPTA),对图像数据进行分析,对膝关节炎进行X线K/L分级,通过SPSS 17.0统计对下肢力线各参数与关节炎的相关性进行分析。结果:①膝关节下肢全长负重位X线片显示,关节有不同程度骨质增生,关节间隙变窄。②51膝骨关节炎中确诊膝内翻畸形38膝(74.51.%)和膝外翻畸形8膝(10.42%),5膝均无内外翻畸形。③膝关节炎X线K/L分级显示,0级:5膝(9.8%),I级:12膝(23.5%),II级:22膝(43.1%);III级:9膝(17.6%);IV级:3膝(59%)。④膝内翻组中股骨内翻7膝(18.42%),胫骨内翻18膝(47.36%),股骨、胫骨均内翻13膝(34.21%);膝外翻组中股骨外翻6膝,股骨、胫骨均外翻2膝。⑤在膝内翻组中,aFTA与骨关节炎X线K/L分级呈正相关(B值=0.132,t=2.648,P=0.012,P<0.05)。结论:下肢全长负重X线显示下肢结构清晰、完整,通过测量下肢力线参数评估,可全面诊断膝关节炎的内翻畸形或外翻畸形,膝内翻中以胫骨内翻显著,膝外翻中则以股骨外翻显著。因此,膝关节骨性关节炎的下肢全长负重X线检查具有较高的临床价值。     

膝关节可调外翻矫形器在膝骨关节炎中的应用

目的：观察膝内侧间室骨性关节炎患者在规范化运动疗法的基础上佩戴自制改进膝关节可调外翻矫形器的效果。方法：60例膝内侧骨性关节炎患者,随机分为观察组和对照组各30例,对照组给予运动疗法治疗,观察组在此基础上佩戴定制矫形器训练,治疗前后进行McMaster大学骨关节炎指数评分（WOMAC）。结果：治疗后1d ,观察组WOMAC评分较治疗前显著减少（P＜0．05）,治疗后1周、1个月时 WOMAC 评分继续明显下降（P＜0．05）,治疗后2、3个月无明显变化;而对照组在治疗1个月后,WOMAC评分才较治疗前显著减少（P＜0．05）,第2、3个月WOMAC评分无显著变化。治疗后,观察组WOMAC评分均较对照组同时间点明显减少（P＜0．05）。结论：自制改进膝关节可调外翻矫形器对行运动疗法的膝内侧间室骨性关节炎患者有明显疗效。     

ICB足底矫形鞋垫结合本体感觉训练对膝关节骨性关节炎患者平衡功能的影响

目的:观察ICB足底矫形鞋垫结合本体感觉训练对膝关节骨性关节炎患者平衡功能的影响。方法:60例膝关节骨性关节炎患者随机分为2组各30例,对照组进行本体感觉训练,观察组在此基础上佩戴ICB足底矫形鞋垫。结果:治疗后及治疗后1个月,2组平衡功能及运动学参数均较治疗前明显提高(P0.05),且观察组均更优于对照组(P0.05)。治疗后及治疗后1个月,观察组踝关节外翻角度、踝关节外翻力矩及地面反作用力(内侧方向)均较治疗前及对照组增加(P0.05),膝关节内收力矩及膝关节内收冲量均较治疗前及对照组减小(P0.05),步速、步幅及地面反作用力(垂直方向)观察组治疗前后各时间点比较差异无统计学意义;对照组治疗前后各时间点运动学参数比较均差异无统计学意义。结论:ICB足底矫形鞋垫结合本体感觉训练可明显改善膝关节骨关节炎患者的平衡功能,值得临床推广。     

开放楔形胫骨高位截骨术治疗膝关节内侧间室骨性关节炎对髌骨参数及关节功能的影响

目的探讨开放楔形胫骨高位截骨术(OWHTO)治疗膝关节内侧间室骨性关节炎对髌骨参数及关节功能的影响。方法回顾性分析2018年7月—2020年6月收治的膝关节内侧间室骨性关节炎98例的临床资料,按照术式分为研究组45例和对照组53例。研究组给予OWHTO治疗,对照组给予单髁置换术(UKA)治疗。比较两组手术前后膝关节疼痛评分、关节功能评分、胫股角(FTA)、胫骨后倾角(PTS)、髌骨高度及并发症情况。结果术后两组视觉模拟评分法评分均呈逐渐下降趋势(P<0.05),但两组间手术前后不同时间比较差异无统计学意义(P>0.05)。术后两组美国特种外科医院(HSS)评分均呈逐渐上升趋势,且研究组高于对照组(P<0.05)。两组术后6个月FTA均较术前下降(P<0.05),但两组间比较差异无统计学意义(P>0.05);两组手术前后及组间PTS比较差异无统计学意义(P>0.05)。研究组术后6、12个月ISI、CDI、BPI均高于对照组(P<0.05)。两组并发症发生率比较差异无统计学意义(P>0.05)。结论OWHTO治疗膝关节内侧间室骨性关节炎效果确切,可有效缓解疼痛并改善关节功能,且力线纠正理想,对髌骨高度影响较小。     

骨水泥型与非骨水泥型全膝关节置换后的步态差异

背景：全膝关节置换已经被证明是一种有效治疗膝骨性关节炎的方法,但是不同类型的全膝关节置换假体固定方式术后所产生的膝关节下肢生物力学差异至今仍不明确。目的：通过三维步态分析骨水泥固定和非骨水泥固定两种不同的全膝关节置换术后患者的膝关节生物力学差异。方法：分别选取骨水泥型全膝关节置换以及非骨水泥型全膝关节置换患者各16例,通过测力台以及三维步态分析系统比较2组患者术前以及术后3个月的膝关节生物力学变化并进行对比。结果与结论：与手术前相比两组患者术后步速及步长均明显增加,支撑相在整个步态周期中的百分比明显减小,膝关节屈在支撑相及摆动相中最大屈曲角度均明显增加,膝关节外翻角度增加。两种患者术后膝关节内翻角度以及膝关节内收力矩均明显减小。提示,骨水泥型与非骨水泥型全膝关节置换术均能有效改善膝骨性关节炎患者的步行能力以及下肢关节功能,两者间未见明显生物力学差异。     

骨水泥型与非骨水泥型全膝关节置换后的步态差异

背景:全膝关节置换已经被证明是一种有效治疗膝骨性关节炎的方法,但是不同类型的全膝关节置换假体固定方式术后所产生的膝关节下肢生物力学差异至今仍不明确。目的:通过三维步态分析骨水泥固定和非骨水泥固定两种不同的全膝关节置换术后患者的膝关节生物力学差异。方法:分别选取骨水泥型全膝关节置换以及非骨水泥型全膝关节置换患者各16例,通过测力台以及三维步态分析系统比较2组患者术前以及术后3个月的膝关节生物力学变化并进行对比。结果与结论:与手术前相比两组患者术后步速及步长均明显增加,支撑相在整个步态周期中的百分比明显减小,膝关节屈在支撑相及摆动相中最大屈曲角度均明显增加,膝关节外翻角度增加。两种患者术后膝关节内翻角度以及膝关节内收力矩均明显减小。提示,骨水泥型与非骨水泥型全膝关节置换术均能有效改善膝骨性关节炎患者的步行能力以及下肢关节功能,两者间未见明显生物力学差异。     

Effects of foot orthoses and valgus bracing on the knee adduction moment and medial joint load during gait

BACKGROUND: Lateral shoe wedges and valgus knee braces are designed to decrease the force acting in the medial knee compartment by reducing the external adduction moment applied at the knee. The biomechanical changes introduced by these orthoses can be relatively small. Computer modeling and simulation offers an alternative approach for assessing the biomechanical performance of these devices. METHODS: A three-dimensional model of the lower-limb was used to calculate muscle, ligament, and joint loading at the knee during gait. A lateral shoe wedge was simulated by moving the center of pressure of the ground reaction force up to 5mm laterally. A valgus knee brace was simulated by applying abduction moments of up to 12 Nm at the knee. FINDINGS: Knee adduction moment and medial compartment load decreased linearly with lateral displacement of the center of pressure of the ground reaction force. A 1 mm displacement of the center of pressure decreased the peak knee adduction moment by 2%, while the peak medial compartment load was reduced by 1%. Knee adduction moment and medial compartment force also decreased linearly with valgus moments applied about the knee. A 1 Nm increase in brace moment decreased the peak knee adduction moment by 3%, while the peak medial compartment load was reduced by 1%. INTERPRETATION: Changes in knee joint loading due to lateral shoe wedges and valgus bracing are small and may be difficult to measure by conventional gait analysis methods. The relationships between lateral shift in the center of pressure of the ground force, valgus brace moment, knee adduction moment, and medial joint load can be quantified and explained using computer modeling and simulation. These relationships may serve as a useful guide for evaluating the biomechanical efficacy of a generic wedge insole or knee brace.     

Effects of disease severity on response to lateral wedged shoe insole for medial compartment knee osteoarthritis

OBJECTIVE: To determine the effects of lateral wedged insoles on knee kinetics and kinematics during walking, according to radiographic severity of medial compartment knee osteoarthritis (OA). DESIGN: A prospective case control study of patients with medial compartment OA of the knee. SETTING: Gait analysis laboratory in a university hospital. PARTICIPANTS: Forty-six medial compartment knees with OA of 23 patients with bilateral disease and 38 knees of 19 age-matched healthy subjects as controls. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: We measured the peak external adduction moment at the knee during the stance phase of gait and the first acceleration peak after heel strike at the lateral side of the femoral condyles. Kellgren and Lawrence grading system was used for radiographic assessment of OA severity. RESULTS: The mean value of peak external adduction moment of the knee was higher in OA knees than the control. Application of lateral wedged insoles significantly reduced the peak external adduction moment in Kellgren-Lawrence grades I and II knee OA patients. The first acceleration peak value after heel strike in these patients was relatively high compared with the control. Application of lateral wedged insoles significantly reduced the first acceleration peak in Kellgren-Lawrence grades I and II knee OA patients. CONCLUSIONS: The kinetic and kinematic effects of wearing of lateral wedged insoles were significant in Kellgren-Lawrence grades I and II knee OA. The results support the recommendation of use of lateral wedged insoles for patients with early and mild knee OA.     

The use of a lateral wedge insole to reduce knee loading when ascending and descending stairs in medial knee osteoarthritis patients

Background

Stair climbing is a challenging task to the elderly being the task with the first complaint in patients with mild to moderate knee osteoarthritis. Stair climbing results in around six times more compressive load transmitted through the knee joint than walking on level ground. The purpose of this study was to assess whether lateral wedge insoles would reduce medial compartment knee loading when ascending and descending stairs in patients with medial knee osteoarthritis.

Methods

Eight patients with medial knee osteoarthritis were tested in random order with and without a pair of 5° off-the-shelf lateral wedge insoles for two separate activities (stair ascent and stair descent). Kinematic and kinetic data were collected for the lower extremity using a sixteen camera motion capture system and two force plates. Primary outcome measures were the external knee adduction moment and the knee adduction angular impulse.

Findings

During stair ascent and descent, lateral wedge insoles significantly (P < 0.05) reduced the 1st peak external knee adduction moment in early stance (ascent 6.8%, descent 8.4%), the trough in mid stance (ascent 13%, descent 10.7%), 2nd peak in the late stance (ascent 15%, descent 8.3%) and the knee adduction angular impulse compared to the control (standard shoe) with large effect sizes (0.75–0.95).

Interpretation

In this first study on stairs, lateral wedge insoles consistently reduced the overall magnitude of medial compartment loading during stair ascent and descent. Further research is needed to determine the relationship of this with clinical results when ascending and descending stairs with lateral wedge insoles.     

Inconsistent knee varus moment reduction caused by a lateral wedge in knee osteoarthritis

OBJECTIVE: To determine--with the assistance of a larger sample size--whether the inconsistency of reducing the knee-joint varus moment with a lateral wedge in patients with medial compartment knee osteoarthritis (OA) persists and if so, what underlying mechanisms may explain it. DESIGN: Crossover design whereby 51 patients with bilateral isolated medial compartment knee OA and 19 age-matched healthy controls walked with two different wedge conditions: a 0-degree control wedge and a 6-degree lateral wedge. We conducted three-dimensional motion analysis, hip-knee-ankle (HKA) angle measurement, and radiologic assessment with Kellgren-Lawrence grade. We investigated frontal plane angles and moments at the knee and subtalar joints, ground reaction forces, and center of pressure (CoP). Moments were derived using a three-dimensional inverse dynamics model of the lower extremity. RESULTS: Nine patients (17.6%) had an increased knee-joint varus moment with the 6-degree lateral wedge via the medially shifted location of the CoP. These patients did not differ from the remaining patients in HKA angle and radiologic assessment. CONCLUSION: In approximately 18% of patients with bilateral medial compartment knee OA, the 6-degree lateral wedge seems to fail to reduce the knee-joint varus moment. The indication and limitations of lateral wedge should be confirmed by a randomized controlled study.     

Static and dynamic biomechanics of foot orthoses in people with medial compartment knee osteoarthritis

OBJECTIVE: 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. DESIGN: Repeated measures design in which subjects were exposed to three conditions (normal footwear, heel wedge and orthosis) in random order. BACKGROUND: 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. METHODS: 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. RESULTS: 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). CONCLUSIONS: 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. RELEVANCE: 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.     

The influence of sole wedges on frontal plane knee kinetics, in isolation and in combination with representative rigid and semi-rigid ankle-foot-orthoses

BACKGROUND: In earlier stages of knee osteoarthritis orthotic treatments with knee orthoses or modified footwear are often considered. Although the load reducing effects of knee orthoses have been well established, wearing modified footwear would be more comfortable for the patient and less encumbering. The effect of modified footwear on the frontal load of the knee is controversial. This article describes the effect of medial or lateral shoe wedges alone or together with two different types of ankle-stabilizing orthoses. METHODS: The effect on frontal knee loading was measured during standing and walking with medially and laterally placed wedges under the sole of the shoe. The wedges were also combined with two types of orthotic devices - an Ankle-Foot-Orthosis that was rigid in the frontal plane but allowed unrestricted sagittal plane motion and an ankle support that was semi-rigid in the frontal plane. Joint loading of 10 healthy persons (mean (standard deviation): age 34 (9) years, height 178 (4)cm, mass 73 (9)kg) was investigated by means of a special measuring device that accurately determines static loads (Lasar Posture) and with instrumented gait analysis (Vicon/Kistler). FINDINGS: Using a lateral wedge under the sole of the shoe (without orthotic support) showed no significant reduction in the mean maximal knee moment in the frontal plane. Adding an Ankle-Foot-Orthosis that is rigid in the frontal plane resulted in significant reduction in the maximal frontal moment from 0.54 Nm/kg to 0.38Nm/kg (p0.01). Using a medial wedge, without and with Ankle-Foot-Orthosis, produced a significant increase in the maximal frontal moment to 0.59 Nm/kg (p0.05) or 0.67 Nm/kg (p0.01), respectively. INTERPRETATION: These results suggest that the application of a sole wedge significantly influences frontal knee loading when used in combination with an Ankle-Foot-Orthosis that is rigid in the frontal plane.     

The dose–response relationship between lateral foot wedging and the reduction of knee adduction moment

BackgroundLateral foot wedges represent a biomechanical intervention aimed at reducing medial knee loads. However, the effects of varying wedge amounts on biomechanical variables and orthotic comfort have not been systematically studied. Further, arch height may influence the comfort of laterally wedged devices. Therefore, the primary purpose of this study was to examine the effect of incrementally increasing lateral wedge amounts on knee adduction moment parameters and subjective comfort. The secondary purpose was to relate arch height measures to the comfort of the devices.MethodsTwenty-five healthy subjects underwent three-dimensional instrumented gait analysis testing using seven inclinations of lateral wedging (0°, 2°, 4°, 6°, 8°, 10°, 12°). Subjects reported comfort level for each orthotic condition. Arch heights were measured in standing and sitting, and rigidity index and stiffness were calculated.FindingsThe knee adduction moment decreased with wedge amounts up to 6°, but more aggressive amounts did not yield additional reductions. Comfort ratings did not change from baseline until wedge amounts exceeded 8°. In addition, arch height measures, arch rigidity index and stiffness did not relate to the comfort of the orthotic device regardless of the wedge amount.InterpretationKnee adduction moment decreased with mild wedge amounts while maintaining comfort. Wedge amounts greater than 6° yielded little additional mechanical benefit and amounts greater than 8° compromised comfort. It appears that 4°–6° of lateral wedging are optimal in regard to desirable biomechanical change and comfort level in healthy individuals.     

膝类风湿关节炎与骨关节炎的MRI与病理对照研究

目的：对比分析膝类风湿关节炎（Rheumatoid arthritis,RA）与骨关节炎（Osteoarthritis,OA）的MRI和病理表现特点,进一步分析RA的病变机制.方法：收集我院确诊的行全膝关节置换术（Total knee arthroplasty,TKA）并进行组织病理学检查的RA患者12例和OA患者10例,比较二者的MRI表现以及所对应部位组织病理学的表现特点.结果：膝RA及OA组髌股关节、胫股内侧关节软骨病变差异无统计学意义（P＞0.05）,胫股外侧关节软骨病变差异具有显著统计学意义（P＜0.05）,胫股内、外关节软骨下骨病变差异具有统计学意义（P＜0.05）,膝RA及OA组内、外半月板前角、体部、后角病变差异具有显著统计学意义（P＜0.05）.膝RA关节软骨、软骨下骨及半月板病理学发现大量炎细胞浸润、血管增生,OA组仅见软骨纤维化、半月板基质黏液性变性,少见炎细胞、血管增生.结论：RA组膝关节各部分的破坏程度普遍高于OA组,病理学提示可能与血管炎有关.     

Effectiveness of a lateral-wedge insole on knee varus torque in patients with knee osteoarthritis

OBJECTIVES: To test whether a lateral-wedged insole, inclined at 5 degrees or 10 degrees, significantly reduces knee varus torque during walking in patients with knee osteoarthritis compared with both using no insole and with wearing nonwedged control insoles of the same material and average thickness. DESIGN: Patients with medial knee osteoarthritis were studied while they walked wearing their comfortable shoes (1) without an insole; (2) with a 5 degrees lateral wedge compared with a nonwedged, 3.175-mm (1/8-in) even-thickness control insole; and (3) with a 10 degrees lateral wedge compared with a nonwedged 6.35-mm ((1/4)-in) even-thickness control insole. SETTING: A gait laboratory with 3-dimensional motion analysis and force platform equipment. PARTICIPANTS: Fifteen patients with clinical and radiographic osteoarthritis of the medial compartment of 1 knee. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Peak external knee varus torques during the stance period of gait. Data regarding lower-extremity joint torques and motions were collected, and knee joint torques using the different insoles and wedges were compared by analysis of variance. RESULTS: Although responses varied among individuals, as a group, both the 5 degrees and 10 degrees lateral-wedge insoles significantly reduced the knee varus torque during walking compared with walking with no insole and walking with nonwedged 3.175-mm and 6.35-mm control insoles. Compared with no insole, the 5 degrees wedge reduced the peak knee varus torque values by about 6% and the 10 degrees wedge reduced the peaks by about 8%. Although there were no significant differences in speed of walking between the conditions, the 10 degrees wedge and 6.35-mm control insoles were associated with varying degrees of discomfort. CONCLUSION: Both wedge insoles are effective in reducing the varus torque during walking beyond what theoretically could be explained by a reduced walking speed or cushioning effect from the insole. These data imply that wedged insoles are biomechanically effective and should reduce loading of the medial compartment in persons with medial knee osteoarthritis. Although the effect of the 5 degrees wedge was smaller, it may be more comfortable than the 10 degrees wedge to wear inside one's own shoes.