The effect of valgus bracing on the knee adduction moment during gait and running in male subjects with varus alignment

Background

Increased mechanical load is one risk factor for osteoarthritis. One possible treatment for this disorder is the use of knee braces in order to redistribute joint loading, which may inhibit the progression of the disease. The hypothesis was: knee adduction moment can be reduced with the use of a dedicated knee orthosis, which applies an abduction moment at the knee.

Methods

Sixteen healthy male subjects with varus alignment were analysed during walking and running while using an adjustable valgus orthosis. Peak knee adduction moments and knee adduction angular impulses were evaluated through inverse dynamics. Additionally, the abduction moment produced by the orthosis was measured in three different adjustments of valgus angulations (neutral, 4° and 8° valgus) using a strain gauge device.

Findings

During walking, mean reductions of 25% and 36% in the knee adduction angular impulse were found between the conditions without orthosis and 4° and between without orthosis and 8°, respectively. For the running trials mean reductions of 18% and 23% were observed between these same conditions. The first and second peak knee adduction moments also decreased during walking with different orthosis adjustments (changes from 5% to 33%). During running, a significant reduction was observed only between the conditions without orthosis and 8° valgus adjustments (change of 11%).

Interpretation

The orthosis tested in this study was effective in reducing the knee adduction moments during walking and running. This reduction of knee adduction moments during locomotion should contribute to decelerate osteoarthritis progression.     

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。     

Peak knee adduction moment during gait in anterior cruciate ligament reconstructed females

Background

Recent work has shown that anterior cruciate ligament reconstructed patients exhibit an increased peak knee adduction moment during walking gait compared to healthy controls. An increased peak knee adduction moment has been suggested to be a potential mechanism of degeneration for knee osteoarthritis. The few studies in this area have not considered an exclusively female anterior cruciate ligament reconstructed group. This study tested the hypothesis that female anterior cruciate ligament-reconstructed patients would have higher peak knee adduction moments than controls.

Methods

Peak knee adduction moment during walking was compared between a group of anterior cruciate ligament reconstructed females and a group of female activity matched controls over ten 15 m walking trials in a laboratory at a self-selected pace.

Findings

Peak knee adduction moment was lower for the anterior cruciate ligament reconstructed group (N = 17, M = 0.31 Nm/kg·m, SD = 0.08) than for the control group (N = 17, M = 0.41 Nm/kg·m, SD = 0.12; t(32) = 2.483, p = 0.010, one-tailed, eta squared effect size = 0.16).

Interpretation

A group of female anterior cruciate ligament reconstructed subjects did not exhibit a gait characteristic which has been suggested to be associated with knee osteoarthritis development and has been shown to be present in male and mixed sex anterior cruciate ligament reconstructed populations previously.     

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。     

Comparison of peak knee adduction moment and knee adduction moment impulse in distinguishing between severities of knee osteoarthritis

Background

The peak knee adduction moment is a valid proxy for medial knee joint loading. However as it only measures load at one instance of stance, knee adduction moment impulse, a measure that takes into account both the magnitude and duration of the stance phase, may provide more comprehensive information. This study directly compared the abilities of peak knee adduction moment and knee adduction moment impulse to distinguish between knee osteoarthritis severities.

Methods

169 participants with medial knee osteoarthritis completed radiographic and magnetic resonance imaging, the Western Ontario and McMaster Universities Arthritis Index to assess pain and a three-dimensional gait analysis. Participants were classified using four dichotomous classifications: Kellgren–Lawrence grading, alignment, medial tibiofemoral bone marrow lesions, and pain.

Findings

When using Kellgren–Lawrence grade and alignment classifications, the area under the receiver operator curves were significantly greater for knee adduction moment impulse than for peak knee adduction moment. Based on analysis of covariance, knee adduction moment impulse was significantly different between Kellgren–Lawrence grade and alignment groups while peak knee adduction moment was not significantly different. Both peak knee adduction moment and knee adduction moment impulse distinguished between bone marrow lesion severities while neither measure was significantly different between pain severity groups.

Interpretations

Findings suggest knee adduction moment impulse is more sensitive at distinguishing between disease severities and may provide more comprehensive information on medial knee joint loading. Future studies investigating biomechanics of knee osteoarthritis should include knee adduction moment impulse in conjunction with peak knee adduction moment.     

The effect of gait modification on the external knee adduction moment is reference frame dependent

BACKGROUND: This study investigated the extent to which reference frame convention affects the interpretation of how gait modification alters the external knee adduction moment. METHODS: Data were collected from a single male able-bodied subject performing three gait tasks: normal, toe out and medial thrust. The net external moment vector at the knee was expressed in five alternative reference frames: the femur anatomical frame, the proximal tibia anatomical frame, the distal tibia anatomical frame, the laboratory frame and a non-orthogonal knee joint coordinate system. For each reference frame, the knee adduction moment was taken as the component about the frame's anteroposterior axis. FINDINGS: Gait modification and selected reference frame both influenced the calculated knee adduction moment. Furthermore, these two effects were interactive, with the magnitude of the changes in the knee adduction moment produced by toe out and medial thrust gait being highly dependent on selected reference frame. INTERPRETATION: Choice of reference frame for calculating the external knee adduction moment is therefore an important consideration for studies investigating the relative effectiveness of interventions such as gait modification.     

Effects of foot orthoses on gait patterns of flat feet patients

BackgroundAlthough foot orthotics are widely prescribed for the treatment of flatfoot, the biomechanical effects of such devices are not yet fully clear. Accordingly, this study conducted an experimental investigation to evaluate the effects of orthoses on the gait patterns of patients with flatfoot during level walking.MethodsEleven adults with flatfoot deformities were recruited. For each participant, kinematic and kinetic data were measured under three test conditions, i.e. walking barefoot, walking with shoes, and walking with shoes and insoles. During each test, the participants’ gaits patterns were recorded and analyzed using a motion analysis system, two Kistler force plates and EVaRT software.FindingsThe results showed that walking with shoes and insoles and walking with shoes conditions increased the peak ankle dorsiflexion angle and moment, and also reduced the peak ankle plantarflexion angle and moment. Furthermore, walking with shoes and insoles and walking with shoes conditions increased the peak knee varus moment. The effects of the orthoese on knee and hip were minimal and no significant differences were observed between walking with shoes and insoles and walking with shoes.InterpretationThe results suggested that the foot insoles and shoes developed in this study might benefit the ankle joint in patients with flat feet. In view of the minimal changes between walking with shoes and insoles and walking with shoes, further studies may be required to clarify the interaction between the foot and the insole/shoe.     

Effects of neuro-developmental treatment and orthoses on knee flexion during gait: a single-subject design

The interactive effects of neuro-developmental treatment and inhibitive ankle-height orthoses on gait were examined via a single-subject research design. Knee flexion during gait at initial contact, mid-stance, heel-off, and mid-swing were measured in a 2-year-old girl with diplegia by use of a goniometer and freeze-frame videography. During the treatment and treatment/orthoses phases, a decrease in excessive knee flexion was noted. Changes in trend over time were greater in the 3-week treatment phase than in the 3-week treatment/orthoses phase. Changes in level at the initiation of the treatment/orthoses phase were greater than in the treatment phase. The described neuro-developmental treatment activities were conducted correctly 92% of the time according to an independent observer. The interrater reliability of goniometric data measured by videography was .93 using intraclass correlation coefficients. The results of this study suggest that both methods of treatment can be used to decrease excessive knee flexion during gait in a child with diplegia.     

Individual selection of gait retraining strategies is essential to optimally reduce medial knee load during gait

Background

The progression of medial knee osteoarthritis seems closely related to a high external knee adduction moment, which could be reduced through gait retraining. We aimed to determine the retraining strategy that reduces this knee moment most effective during gait, and to determine if the same strategy is the most effective for everyone.

Methods

Thirty-seven healthy participants underwent 3D gait analysis. After normal walking was recorded, participants received verbal instructions on four gait strategies (Trunk Lean, Medial Thrust, Reduced Vertical Acceleration, Toe Out). Knee adduction moment and strategy-specific kinematics were calculated for all conditions.

Findings

The overall knee adduction moment peak was reduced by Medial Thrust (− 0.08 Nm/Bw·Ht) and Trunk Lean (− 0.07 Nm/Bw·Ht), while impulse was reduced by 0.03 Nms/Bw·Ht in both conditions. Toeing out reduced late stance peak and impulse significantly but overall peak was not affected. Reducing vertical acceleration at initial contact did not reduce the overall peak. Strategy-specific kinematics (trunk lean angle, knee adduction angle, first peak of the vertical ground reaction force, foot progression angle) showed that multiple parameters were affected by all conditions. Medial Thrust was the most effective strategy in 43% of the participants, while Trunk Lean reduced external knee adduction moment most in 49%. With similar kinematics, the reduction of the knee adduction moment peak and impulse was significantly different between these groups.

Interpretation

Although Trunk Lean and Medial Thrust reduced the external knee adduction moment overall, individual selection of gait retraining strategy seems vital to optimally reduce dynamic knee load during gait.     

Contribution of knee adduction moment impulse to pain and disability in Japanese women with medial knee osteoarthritis

Background

An increase in the knee adduction moment is one of the risk factors of medial knee osteoarthritis. This study examined the relationship between knee adduction moment and self-reported pain and disability. We also investigated the influence of pain on the relationships between knee adduction moment and gait performance and disability.

Methods

Thirty-eight Japanese women with medial knee osteoarthritis participated in this study (66.37 years (41–79 years)). Gait analysis involved the measurement of the external knee adduction moment impulse in the stance duration and during 3 subdivisions of stance. The total, pain and stiffness, and physical function Japanese Knee Osteoarthritis Measure scores were determined.

Findings

The pain and stiffness, physical function, and total scores were positively correlated with the knee adduction moment impulses in the stance duration, and initial and second double support interval, and single limb support interval. The knee adduction moment impulse during the stance duration was related to the pain and stiffness subscale and gait velocity. The pain and stiffness subscale was related to the physical function subscale.

Interpretation

Our results suggest that increasing in the knee adduction moment impulse, a proxy for loading on the medial compartment of the knee, is related to increased pain during weight-bearing activities such as walking, thereby restricting walking performance and causing disability by reducing gait velocity. Thus, the reduction in the knee adduction moment impulse during gait may result in pain relief and may serve as a conservative treatment option with disease-modifying potential.     

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.     

Effects of foot orthoses on Achilles tendon load in recreational runners

Background

Achilles tendon pathology is a frequently occurring musculoskeletal disorder in runners. Foot orthoses have been shown to reduce the symptoms of pain in runners but their mechanical effects are still not well understood.

Methods

This study aimed to examine differences in Achilles tendon load when running with and without orthotic intervention. Twelve male runners ran at 4.0 m·s^− 1. Ankle joint moments and Achilles tendon forces were compared when running with and without orthotics.

Findings

The results indicate that running with foot orthotics was associated with significant reductions in Achilles tendon load compared to without orthotics.

Interpretation

In addition to providing insight into the mechanical effects of orthotics in runners, the current investigation suggests that via reductions in Achilles tendon load, foot orthoses may serve to reduce the incidence of chronic Achilles tendon pathologies in runners.     

Effects of foot orthoses on skeletal motion during running

OBJECTIVE: To quantify the effects of medial foot orthoses on skeletal movements of the calcaneus and tibia during the stance phase in running. DESIGN: Kinematic effects of medial foot orthoses (anterior, posterior, no support) were tested using skeletal (and shoe) markers at the calcaneus and tibia. BACKGROUND: Previous studies using shoe and skin markers concluded that medially placed orthoses control/reduce foot eversion and tibial rotation. However, it is currently unknown if such orthoses also affect skeletal motion at the lower extremities. METHODS: Intracortical Hofman pins with reflective marker triads were inserted under standard local anesthetic into the calcaneus and tibia of five healthy male subjects. The three-dimensional tibiocalcaneal rotations were determined using a joint coordinate system approach. Eversion (skeletal and shoe) and tibial rotation were calculated to study the foot orthoses effects. RESULTS: Orthotic effects on eversion and tibial rotations were found to be small and unsystematic over all subjects. Differences between the subjects were significantly larger (p<0.01; up to 10 degrees ) than between the orthotic conditions (1-4 degrees ). Significant orthotic effects across subjects were found only for total internal tibial rotation; p<0.05). CONCLUSIONS: This in vivo study showed that medially placed foot orthoses did not change tibiocalcaneal movement patterns substantially during the stance phase of running. RELEVANCE: Orthoses may have only small kinematic effects on the calcaneus and tibia (measured with bone pins) as well as on the shoes (measured with shoe markers) during running of normal subjects. Present results showed that orthotic effects were subject specific and unsystematic across conditions. It is speculated that orthotic effects during the stance phase of running may be mechanical as well as proprioceptive.     

The effect of foot orthoses on joint moment asymmetry in male children with flexible flat feet

Introduction

It has been widely postulated that structural and functional misalignments of the foot, such as flat foot, may cause mechanical deviations of the lower limb during walking. The aim of this study was to investigate the effect of foot orthoses on lower extremity joint moment asymmetry during the stance phase of walking in children with asymptomatic flexible flat feet.

Explaining the hip adduction moment variability during gait: Implications for hip abductor strengthening

Background

There is emerging interest in hip abductor function during gait and its potential relationship to knee joint pathology. During gait, the hip abductor muscles are primarily responsible for generating moments of force to control frontal plane movement. The current study investigated the relationship between hip abductor muscle function and frontal plane hip moments of force during gait.

Methods

Frontal plane hip moments of force and electromyographic features of gluteus medius were measured during walking in 22 healthy individuals. Hip abductor strength, subject anthropometrics and gait velocity were recorded. Multiple regression models were used to evaluate the relationship between the anthropometric, velocity, strength and electromyographic variables and the initial and mid-stance magnitude of the hip adduction moment.

Findings

A positive relationship was found between the initial peak moment (Nm), and both body mass and gait speed (R² = 90%). Body mass (positive) and hip abductor strength (negative) explained significant levels of mid-stance magnitude variability (R² = 62.5%). Gait speed (positive) explained significant levels of variability in the normalized initial peak moment (Nm/kg) (R² = 52%). No variables were included in the normalized mid-stance moment model (P > 0.05).

Interpretation

Body mass was the key factor associated with high hip adduction moments during initial and mid-stance of the gait cycle. Increased gait velocity was associated with higher initial peaks and higher muscle strength was associated with lower mid-stance magnitude of the external hip adductor moment during walking. These findings suggest that in a healthy adult population, hip abductor strength and activation were not directly related to the hip adduction moment magnitude during gait.     

Effects of unloading bracing on knee and hip joints for patients with medial compartment knee osteoarthritis

Background

Osteoarthritis affects the whole body, thus biomechanical effects on other joints should be considered. Unloading knee braces could be effective for knee osteoarthritis, but their effects on the contralateral knee and bilateral hip joints remain unknown. This study investigated the effects of bracing on the kinematics and kinetics of involved and contralateral joints during gait.

Methods

Nineteen patients with medial compartment knee osteoarthritis were analysed. Kinematics and kinetics of the knee and hip joints in frontal and sagittal planes were measured during walking without and with bracing on the more symptomatic knee.

Findings

The ipsilateral hip in the braced condition showed a lower adduction angle by an average of 2.58° (range, 1.05°–4.16°) during 1%–49% of the stance phase, and a lower abduction moment at the second peak during the stance phase than the hip in the unbraced condition (P < 0.05 and P < 0.005, respectively). With bracing, the contralateral hip showed a more marked peak extension moment and lower abduction moment at the first peak (P < 0.05), and the contralateral knee adduction angle increased by an average of 0.32° (range, 0.21°–0.45°) during 46%–55% of the stance phase (P < 0.05), compared to no bracing.

Interpretation

Unloading bracing modified the contralateral knee adduction angle pattern at a specific time point during gait. It also affected the frontal plane on the ipsilateral hip and the frontal and sagittal planes on the contralateral hip joint. Consideration should be provided to other joints when treating knee osteoarthritis.     

The effect of orthotic devices on knee adduction moment,pain and function in medial compartment knee osteoarthritis: a literature review

Background Knee braces and foot orthoses are commonly used to improve knee adduction moment, pain and function in subjects with knee osteoarthritis (OA). However, no literature review has been performed to compare the effects of foot orthoses and knee braces in this group of patients. Purpose The aim of this review was to evaluate the effects of foot orthoses and knee braces on knee adduction moment, pain and function in individuals with knee OA. Study design Literature review. Method The search strategy was based on the Population Intervention Comparison Outcome method. A search was performed in PubMed, Science Direct, Google Scholar and ISI web of knowledge databases using the PRISMA method and based on selected keywords. Thirty-one related articles were selected for final evaluation. Results The results of the analysis of these studies demonstrated that orthotic devices reduce knee adduction moment and also improve pain and function in individuals with knee OA. Conclusion Foot orthoses may be more effective in improving pain and function in subjects with knee OA. Both knee braces and foot orthoses reduce the knee adduction moment in knee OA and consequently patients typically do not need to use knee braces for a long period of time. Also, foot orthoses and knee braces may be more effective for medial compartment knee OA patients due to the fact that this treatment helps improve pain and function.

• Implications for Rehabilitation

• Knee braces and foot orthoses are commonly used for improving knee adduction moment, pain and function in subjects with knee osteoarthritis (OA).

• Orthotic devices can reduce knee adduction moment, pain and improve function in knee OA.

• The combined use of a knee braces and foot orthoses can provide more improvement in knee adduction moment, reduced pain and increased function.