Frontal plane motion of the rearfoot during a one-leg squat in individuals with patellofemoral pain syndrome

Abnormal motion of the foot has been suggested to be a potential contributor to the medial collapse of the knee seen in individuals with patellofemoral pain syndrome during a one-leg squat. Rearfoot frontal plane range of motion and peak angle were investigated during a one-leg squat in patients with patellofemoral pain syndrome compared with controls. A significant increase in the peak eversion angle was found for the patellofemoral pain syndrome group compared with controls (P = .02). Increased rearfoot eversion may contribute to the knee medial collapse observed in these patients because it may lead to tibial abduction relative to the femur. Nevertheless, further research is required to investigate the causal relationship because it remains unclear whether rearfoot eversion instigates the medial collapse of the knee.     

The amount of rearfoot motion used during the stance phase of walking

The purpose of this study was to determine the proportion of available passive frontal plane rearfoot motion that is used during the stance phase of walking. Data were collected from 40 healthy, asymptomatic volunteer subjects (20 men and 20 women) aged 23 to 44 years. Passive inversion and eversion motion was measured in a non-weightbearing position by manually moving the calcaneus. Dynamic rearfoot motion was referenced to a vertical calcaneus and tibia and was measured using a three-dimensional electromagnetic motion-analysis system. The results indicated that individuals used 68.1% of their available passive eversion range of motion and 13.2% of their available passive inversion range of motion during walking. The clinical implication of individuals' regularly operating at or near the end point of their available rearfoot eversion range of motion is discussed.     

Use of the longitudinal arch angle to predict dynamic foot posture in walking

To determine whether differences exist in the longitudinal arch angle based on sex or extremity, the longitudinal arch angle was assessed in 21 men and 21 women using a digital image of the medial aspect of each subject's feet. The image was obtained with the subject in relaxed standing posture and in maximum internal rotation of the lower leg. To determine whether the longitudinal arch angle could be used to predict dynamic foot posture during walking, 50 different subjects were asked to walk across a 6-m walkway while the medial aspect of each foot was videotaped. The longitudinal arch angle was digitized from digital images obtained at midstance for three walking trials. No differences in the longitudinal arch angle were found based on sex or extremity. The longitudinal arch angles obtained in the static positions of relaxed standing posture and maximum internal rotation were highly predictive of dynamic foot posture at midstance during walking. Relaxed standing posture and maximum internal rotation significantly contributed to explaining more than 90% of the variance associated with the longitudinal arch angle position at midstance during walking. These results validate use of the longitudinal arch angle as part of the foot and ankle physical examination.     

Application of center-of-pressure data to indicate rearfoot inversion-eversion in shod running

Although pressure plates are used to help in the selection of appropriate footwear for runners, evidence relating aspects of pressure data to movement is lacking. A study was conducted to investigate whether center-of-pressure (COP) data obtained for shod running could be used to indicate the amount of rearfoot eversion. It was hypothesized that subjects exhibiting high rearfoot eversion during the initial ground contact phase of running would also show a large lateral-to-medial deviation in the COP. Pressure plate and rearfoot movement data were collected for 33 subjects. The COP was characterized using the lateral-to-medial deviation of the COP during the eversion phase of ground contact. Correlation coefficients were determined for COP deviation versus rearfoot range of motion and versus peak rearfoot eversion (P < .05). In addition, subjects were grouped as high, moderate, or low pronators, and analysis of variance was used to test whether there were significant differences in COP deviation for these three groups (P < .05). The COP deviation was found to have a low correlation with rearfoot range of motion (R = 0.46; P < .05) and with peak rearfoot eversion (R = .54; P < .05). High pronators had significantly higher COP deviation than the medium- and low-pronation groups (P < .05). These findings support the use of COP deviation to detect high pronation. However, caution is advised in using the COP to indicate absolute rearfoot eversion.     

The effect of rearfoot eversion on maximal hallux dorsiflexion. A preliminary study

Functional hallux limitus has been recently described as an etiologic factor in postural complaints. Eversion of the rearfoot has been theoretically linked to decreased hallux dorsiflexion, although there have been no scientific studies on this subject to date. This study was undertaken to investigate the relationship between rearfoot eversion and hallux dorsiflexion; the results show that hallux dorsiflexion is decreased with rearfoot eversion in a static setting.     

The effect of high-Dye and low-Dye taping on rearfoot motion

High-Dye and low-Dye taping are commonly used by clinicians to treat a variety of foot and ankle pathologies, particularly those associated with excessive rearfoot pronation. While the effects of taping on end range of motion have been extensively studied, relatively little is understood about the effect of the two styles of taping on rearfoot motion. Eighteen participants were analyzed in three conditions: 1) barefoot, 2) with high-Dye taping, and 3) with low-Dye taping. Two-dimensional motion of the rearfoot was assessed for each condition. The results indicated maximum inversion was increased with both high-Dye and low-Dye taping as compared with no taping. Only high-Dye taping, however, significantly reduced the maximum eversion of the rearfoot. The results suggest that high-Dye taping is an appropriate taping choice when control of eversion of the rearfoot is desired.     

Reliability and validity of center-of-pressure quantification

The purpose of this study was to determine the reliability and validity of two center-of-pressure quantification methods. One hundred five individuals (33 men and 72 women) with a mean age of 26.7 years participated in phase 1 of the study. Two measures of the center-of-pressure pattern, the lateral-medial area index and the lateral-medial force index, were calculated from plantar pressure data collected on all subjects. Between-trial reliability of the two measurements was assessed using intraclass correlation coefficients. In phase 2, frontal plane motion of the rearfoot was recorded in 30 individuals. Pearson correlation coefficients were then calculated between the two center-of-pressure indices and the magnitude of rearfoot eversion obtained from each subject during walking. Intraclass correlation coefficient values ranged from 0.374 to 0.889 for the lateral-medial area index and from 0.215 to 0.905 for the lateral-medial force index. Pearson correlation coefficients between the two center-of-pressure indices and the rearfoot kinematic variables ranged from 0.050 to 0.165. The lateral-medial area index and the lateral-medial force index may have adequate between-trial reliability but are not related to the magnitude of frontal plane rearfoot eversion during the stance phase of walking.     

Static rearfoot alignment: a comparison of clinical and radiographic measures

Foot structure is typically evaluated using static clinical and radiographic measures. To date, the literature is devoid of a correlation between rearfoot frontal plane radiographic parameters and clinical measures of alignment. In a repeated-measures study comparing radiographic and clinical rearfoot alignment in 24 healthy subjects, radiographic angular measurements were made from standard weightbearing anteroposterior, lateral, long leg calcaneal axial, and rearfoot alignment views. Clinical measurements were made using a jig and scanner to assess the malleolar valgus index and a goniometer to evaluate the resting and neutral calcaneal stance positions. There was a significant correlation between frontal plane radiographic angles (long leg calcaneal axial and rearfoot alignment views) (r = 0.814). Similarly, there was a significant correlation between clinical measures (resting calcaneal stance position and malleolar valgus index) (r = 0.714). A multivariate stepwise regression showed that resting calcaneal stance position can be accurately predicted from 3 of the 15 clinical and radiographic measurements collected: malleolar valgus index, rearfoot alignment view, and long leg calcaneal axial view (r = 0.829). In summary, a commonly used clinical measure of static rearfoot alignment, resting calcaneal stance position, was correlated closely with the malleolar valgus index and both frontal plane radiographic parameters.     

Effect of foot posture and inverted foot orthoses on hallux dorsiflexion

A pronated foot posture is considered to be a factor in limitation of dorsiflexion at the first metatarsophalangeal joint during weightbearing. Customized foot orthoses are widely used to increase dorsiflexion at the first metatarsophalangeal joint in people with pronated feet. However, the effect of foot posture and customized foot orthoses on maximum first metatarsophalangeal joint dorsiflexion has not been widely investigated. This study sought to determine 1) the relationship between foot posture and static maximum first metatarsophalangeal joint dorsiflexion and 2) the effect of customized foot orthoses on static maximum first metatarsophalangeal joint dorsiflexion in people with pronated feet. Foot posture was assessed using the Foot Posture Index. Static maximum first metatarsophalangeal joint dorsiflexion of the right foot was determined using a goniometer while participants stood relaxed with and without Blake-style inverted (30 degrees) foot orthoses positioned under their feet. There was a significant negative correlation between Foot Posture Index and static maximum first metatarsophalangeal joint dorsiflexion (r = -0.587). Inverted (30 degrees) foot orthoses increased the magnitude of static maximum first metatarsophalangeal joint dorsiflexion from 83.4 degrees to 85.3 degrees in participants with an excessively pronated foot posture. However, this difference was not statistically significant. People with pronated feet are more likely to exhibit limitation of dorsiflexion at the first metatarsophalangeal joint during gait, and inverted foot orthoses are unlikely to be effective in increasing dorsiflexion at the first metatarsophalangeal joint in these people.     

The effect of foot orthoses on patellofemoral pain syndrome

In a retrospective review of 102 patients treated for chondromalacia pa-tellae and patellofemoral pain syndrome/retropatellar dysplasia (PFPS/RPD), the effectiveness of semiflexible foot orthoses was investigated. The combined disorders were diagnosed in 89.3% of the patients. Subjects were 46 women and 54 men, aged 12 to 87 years (mean, 37.9 years; SD, 15.9), who exhibited excessive forefoot varus or rearfoot varus. The initial screening and clinical diagnosis were based on an examination by an orthopedist. Particular attention was directed to patellar crepitation, patellofemoral malalignment, Q-angle measurements, limitation of range of motion, and knee effusion. Patients were evaluated for the onset and duration of patellofemoral pain and degree of knee joint disease. Semiflexible orthoses for each subject were fabricated, based on a clinical lower extremity biomechanical examination. At their follow-up visit, 76.5% were improved and 2% were asymptomatic, showing a significant decrease in the level of pain with orthoses intervention (chi-square P <.001). Although multiple treatment modalities are used for these patients, the results suggest that the use of semiflexible orthoses is significant in reducing symptoms of PFPS/RPD.     

Symmetry of plantar pressures and vertical forces in healthy subjects during walking

The purpose of this study was to determine the degree of symmetry for in-shoe plantar pressure and vertical force patterns between the left and right feet of healthy subjects during walking. Thirty subjects with a mean age of 29.6 years participated in the study. Each subject walked a distance of 8 m three times while in-shoe plantar pressure and vertical force data were collected. A total of 12 steps were analyzed for both feet, and maximum vertical force, peak pressure, and pressure-time integrals were calculated for four plantar regions of the foot. No differences in the three variables were noted between male and female subjects. Plantar pressure and vertical force patterns were found to be symmetrical between the left and right feet, except for two of the four plantar regions studied. Only the forefoot and rearfoot regions were found to show significant differences between the left and right feet for plantar pressure and vertical force, respectively. The degree of asymmetry for these two plantar regions in the same foot, however, was minimal.     

CT scanning and arthroscopic evaluation of patellofemoral malalignment

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Changes in plantar foot pressure with in-shoe varus or valgus wedging

Varus and valgus wedging are commonly used by podiatric physicians in therapy with custom-made foot orthoses. This study aimed to provide scientific evidence of the effects on plantar foot pressure of applying in-shoe forefoot or rearfoot wedging. The plantar foot pressure distribution of 23 subjects walking on a treadmill was recorded using a pressure insole system for seven different wedging conditions, ranging from 3 degrees valgus to 6 degrees varus for the forefoot and from 4 degrees valgus to 8 degrees varus for the rearfoot. The results demonstrate that increasing varus wedging magnifies peak pressure and maximal loading rate at the medial forefoot and rearfoot, whereas increasing valgus wedging magnifies peak pressure and maximal loading rate at the lateral forefoot and rearfoot. As expected, the location of the center of pressure shifts medially with varus wedging and laterally with valgus wedging. However, these shifts are less significant than those in peak load and maximal loading rate. Timing variables such as interval from initial impact to peak load do not seem to be affected by forefoot or rearfoot wedging. Finally, rearfoot wedging does not significantly influence pressure variables of the forefoot; similarly, rearfoot pressure remains unaffected by forefoot wedging.     

COA: Effect of anterior cruciate ligament reconstruction on biomechanical features of knee in level walking: a meta-analysis

Background The anterior cruciate ligament (ACL) is one of the most commonly injured knee ligaments. Even following ACL reconstruction, significant articular cartilage degeneration can be observed and most patients suffer from premature osteoarthritis. Articular cartilage degeneration and osteoarthritis development after ACL injury are regarded as progressive process that are affected by cyclic loading during frequently performed low-intensity daily activities. The purpose of this study was to perform a meta-analysis on studies assessing the effects of ACL reconstruction on kinematics, kinetics and proprioception of knee during level walking. Methods This meta-analysis was conducted according to the methodological guidelines outlined by the Cochrane Collaboration. An electronic search of the literature was performed and all trials published between January 1966 and July 2010 comparing gait and proprioception of a reconstructed-ACL group with an intact-ACL group were pooled for this review. Thirteen studies were included in the final meta-analysis. Results There was no significant difference in step length, walking speed, maximum knee flexion angle during loading response, joint position sense and threshold to detect passive motion between the reconstructed-ACL group and the intact-ACL group (P>0.05). However, there was a significant difference in peak knee flexion angle, maximum angular knee flexion excursion during stance, peak knee flexion moment during walking and maximum external tibial rotation angle throughout the gait cycle between the reconstructed-ACL group and the intact-ACL group (P<0.05). Conclusions Step length, walking speed, maximum knee flexion angle during loading response, joint position sense and threshold to detect passive motion usually observed with ACL deficiency were restored after the ACL reconstruction and rehabilitation, but no significant improvements were observed for peak knee flexion angle, maximum angular knee flexion excursion during stance, peak knee flexion moment during walking and maximum external tibial rotation angle throughout the gait cycle. Methods This meta-analysis was conducted according to the methodological guidelines outlined by the Cochrane Collaboration. An electronic search of the literature was performed and all trials between January 1966 and September 2010 comparing ACL reconstruction group with ACL intact group in gait and proprioception were pooled for this review. Thirteen studies were finally recruited in the meta-analysis. Results There was no significant difference in step length,step speed,maximum knee flexion during loading response,joint position sense and threshold to detect passive motion between ACL reconstruction group and ACL intact group(p>0.05).However,there was a significant difference in peak knee flexion,maximum knee flexion angular joint during stance,knee moment peak knee flexion during walking and maximum tibial rotation during gait cycle between ACL reconstruction group and ACL intact group(p<0.05). Conclusions The step length,step speed,maximum knee flexion during loading response,joint position sense and threshold to detect passive motion for ACL deficiency were restored after the ACL reconstruction and rehabilitation,but no significant improvements were observed in terms of peak knee flexion,maximum knee flexion angular joint during stance,knee moment peak knee flexion during walking and maximum tibial rotation during gait cycle.     

Effect of anterior cruciate ligament reconstruction on biomechanical features of knee in level walking: a meta-analysis

Background The anterior cruciate ligament （ACL） is one of the most commonly injured knee ligaments. Even following ACL reconstruction, significant articular cartilage degeneration can be observed and most patients suffer from premature osteoarthritis. Articular cartilage degeneration and osteoarthritis development after ACL injury are regarded as progressive process that are affected by cyclic loading during frequently performed low-intensity daily activities. The purpose of this study was to perform a meta analysis on studies assessing the effects of ACL reconstruction on kinematics, kinetics and proprioception of knee during level walking.Methods This meta analysis was conducted according to the methodological guidelines outlined by the Cochrane Collaboration. An electronic search of the literature was performed and all trials published between January 1966 and July 2010 comparing gait and proprioception of a reconstructed-ACL group with an intact-ACL group were pooled for this review. Thirteen studies were included in the final meta analysis.Results There was no significant difference in step length, walking speed, maximum knee flexion angle during loading response, joint position sense and threshold to detect passive motion between the reconstructed-ACL group and the intact-ACL group （P 〉0.05）. However, there was a significant difference in peak knee flexion angle, maximum angular knee flexion excursion during stance, peak knee flexion moment during walking and maximum external tibial rotation angle throughout the gait cycle between the reconstructed-ACL group and the intact-ACL group （P 〈0.05）.Conclusions Step length, walking speed, maximum knee flexion angle during loading response, joint position sense and threshold to detect passive motion usually observed with ACL deficiency were restored after the ACL reconstruction and rehabilitation, but no significant improvements were observed for peak knee flexion angle, maximum angular knee flexion excursion during stance, peak knee flexion moment during walking and maximum external tibial rotation angle throughout the gait cycle.     

运用三维步态分析评价下肢机器人训练对偏瘫患者步行能力的影响

正脑血管疾病是导致老年人慢性动作功能受损的主因之一,影响日常生活功能~([1])。机器人辅助疗法是近年来出现的脑卒中康复疗法,具有重复性、专一性、可定量评价等优点~([2-3])。既往评价偏瘫患者下肢机器人训练效果多采用量表评定,结果较主观,三维步态分析具有数据客观、定量、可信度高等优点~([4])。本研究利用三维步态分析系统对比观察脑卒中偏瘫患者经下肢机器人结合本体感觉训练或仅采用本体感觉训练后其三维步态参数的变化情况,评价下肢机器人训练对脑卒中偏瘫患者步行能力的改善效果。     

The effect of 5-degree valgus and varus rearfoot wedging on peak hallux dorsiflexion during gait

The dynamic effects of 5 degrees varus and valgus rearfoot wedging on peak hallux dorsiflexion were investigated in 30 asymptomatic subjects (5 males and 25 females). Statistically significant reductions in peak hallux dorsiflexion were found with rearfoot varus wedging and rearfoot valgus wedging. Furthermore, the reduction in peak hallux dorsiflexion occurring with rearfoot varus wedging was statistically significant compared with that associated with rearfoot valgus wedging. These findings have implications for the orthotic management of a variety of lower-limb pathologies.     

假体内旋与初次全膝关节置换术后疼痛因素的分析

疼痛是全膝关节置换术(TKA)后不满意的常见原因,其通常有感染、无菌性松动等因素,但仍有部分患者无法明确病因。近年研究发现术后不明原因疼 痛可能和旋转力线不良相关,作者分析了本院32例初次TKA术后不明原因膝痛患者的旋转力线,并将其和无疼痛患者比较,探讨术后疼痛和旋转力线的关系。发现疼痛组患者胫骨旋转角、股骨旋转角、联合旋转角、胫股失匹配角均较无疼痛组内旋,两组比较差异均有统计学意义(P<0.05)。两组术后VAS评分、KSS功能评分、膝关节活动度比较,差异均有统计学意义(P<0.05)。故假体内旋是初次TKA术后不明原因疼痛的一大因素,应避免假体过度内旋安放,减少术后疼痛发生。     

膝骨关节炎患者的三维运动解析

背景　膝骨关节炎（KOA）患者发生膝关节变形、活动受限、步态异常等改变,预示KOA是与运动学、动力学等生物力学因素关系密切的一种疾病。而目前临床上缺乏对这些运动学、动力学指标的客观定量评定指标。目的　应用VICON三维运动捕捉系统解析KOA患者的病情,为临床医生治疗、康复计划的制定和实施提供新的重要参考依据。方法　2010年10月-2017年6月,选择上海交通大学医学院附属瑞金医院门诊及住院的双KOA患者10例作为KOA组,另外招募无膝关节疼痛的健康中老年人10例作为对照组。采用英国VICON三维运动捕捉系统对两组受试者进行行走测试,并分析受试者的步行情况和膝关节的生物力学（运动学、动力学）特征。结果　与正常人比较,KOA患者存在明显的步态和生物力学特征：步频、跛行指数、步长、步幅、步速均缩短,双足支撑期、单足支撑期、一步时间、步行周期均延长（P<0.05）;膝关节屈曲角峰值,冠状面最初角度,矢状面、冠状面、水平面膝关节最大活动范围均减小（P<0.05）;膝关节角速度、膝关节角加速度峰值和平均值均减小（P<0.05）;膝关节伸展力矩峰值减小（P<0.05）;Y轴和Z轴方向地板反作用力峰值减小（P<0.05）。结论　KOA患者关节内及其周围生物力学环境发生了明显变化,同时下肢运动出现了异常。而采用VICON运动捕捉系统对KOA患者和正常人进行三维步态分析,有助于更好地了解膝关节运动学和动力学等指标,为KOA诊断、治疗及研究提供重要的参考依据。