A study of the gait characteristics of patients with chronic osteoarthritis of the knee

Purpose : There is scant information at present on the effects of severe osteoarthritis (OA) of the knee joint on gait. In the present study the kinematic and kinetic parameters of gait and the pattern of activation of four lower limb muscles were examined during walking at a self-selected pace on level ground. The spatiotemporal parameters of gait were also computed.

Methods : Measurements were made using a three-dimensional optico-electronic motion analysis system integrated with a force plate and telemetered electromyography.

Results : Fifty-eight patients with severe OA of the knee and 25 age-matched healthy control subjects were examined. Patients demonstrated a significantly reduced walking speed, shorter stride length and a more prolonged stance phase of the gait cycle compared with the control subjects. They also had less range of motion at the hip, knee and ankle, joints and generated less moments and powers at the ankle and more moments at the knee than the control group. The differences were statistically significant for all parameters except the degree of ankle plantar flexion in stance. Activation of the rectus femoris muscle was prolonged in the patients group.

Conclusions : It is concluded that the observed gait abnormalities were due to instability of the knee joint in stance. This may have important clinical implications for the rehabilitation of patients with severe OA of the knee.     

Biomechanical Analysis of Stair Descent in Patients with Knee Osteoarthritis

[Purpose] The purposes of this study were to investigate the lower extremity joint kinematics and kinetics of patients with the knee osteoarthritis (knee OA) during stair descent and clarify the biomechanical factors related to their difficulty in stair descent. [Subjects and Methods] Eight healthy elderly persons and four knee OA patients participated in this study. A 3-D motion analysis system and force plates were employed to measure lower extremity joint angles, ranges of motion, joint moments, joint powers, and ratios of contribution for the joint powers while descending stairs. [Results] Knee joint flexion angle, extension moment, and negative power during the early stance phase in the knee OA group were smaller than those in the healthy subjects group. However, no significant changes in these parameters in the ankle joint were observed between the two subject groups. [Conclusion] Knee OA patients could not use the knee joint to absorb impact during the early stance phase of stair descent. Hence, they might compensate for the roles played by the intact knee joint by mainly using ipsilateral ankle kinematics and kinetics.Key words: Knee osteoarthritis, Stair descent, 3-D motion analysis     

Differences in gait parameters between healthy subjects and persons with moderate and severe knee osteoarthritis: A result of altered walking speed?

Background

While knee osteoarthritis has been shown to affect a multitude of kinematic, kinetic and temporo-spatial gait parameters, few investigations have examined the effect of increasing levels of radiographic osteoarthritis severity on these gait parameters. Fewer still have investigated the effect of walking speed on gait variables in persons with knee osteoarthritis. The objective of this study was to investigate the influence of walking speed on biomechanical variables associated with joint loading in persons with varying severities of medial compartment knee osteoarthritis.

Methods

Twenty-one persons with moderate osteoarthritis (Kellgren–Lawrence score 2–3) and 13 persons with severe osteoarthritis (Kellgren–Lawrence score of 4) participated. Twenty-two persons without knee pain or radiographic evidence of arthritis comprised a healthy control group. Sagittal plane kinetics, knee adduction moment, sagittal plane knee excursion, ground reaction forces and knee joint reaction forces were calculated from three-dimensional motion analysis at 1.0 m/s, self-selected and fastest tolerable walking speeds. Differences were analyzed using multivariate analysis of variance and multivariate analysis of covariance with speed as a covariate.

Findings

Persons with knee osteoarthritis showed significantly lower knee and ankle joint moments, ground reaction forces, knee reaction force and knee excursion when walking at freely chosen speeds. When differences in walking speed were accounted for in the analysis, the only difference found at all conditions was decreased knee joint excursion.

Interpretation

Compared to a healthy control group, persons with knee OA demonstrate differences in joint kinetics and kinematics. Except for knee excursion, these differences in gait parameters appear to be a result of slower freely chosen walking speeds rather than a result of disease progression.     

The relationship between ankle plantar flexor muscle moments and knee compressive forces in subjects with and without pain

OBJECTIVE. The purpose of this study was to compare the compressive knee joint reaction force and ankle plantar flexor muscle moment during the terminal stance phase in symptomatic osteoarthritic and non-symptomatic subjects.DESIGN. The study design was a comparative investigation of walking patterns.BACKGROUND. Patients with knee osteoarthritic symptoms may employ altered gait patterns to reduce the loading of painful joints. Speculation is that decreased ankle plantar flexor moments in the terminal stance phase may be an attempt to minimize compressive knee joint reaction forces.METHODS. Twenty community-dwelling men (52-83 years old), ten with knee osteoarthritis and ten non-symptomatic, were studied while walking across a walkway containing two force plates at a comfortable speed. Retroreflective markers were placed in accordance with the Helen Hayes marker system and recorded with six 120 Hz cameras. Three-dimensional kinematics and kinetics were computed.RESULTS. Group means for gait velocity, peak ankle plantar flexor moment and compressive knee joint reaction force were significantly less for the osteoarthritic group relative to the non-symptomatic group. When accounting for the decreased velocity in the osteoarthritic group, however, no group differences were observed. There were significant correlations between all three gait parameters (r>0.75), but peak ankle plantar flexor moment was the greatest predictor of compressive knee joint reaction force.CONCLUSIONS. While no group differences were found for compressive knee joint reaction forces when accounting for gait velocity, it appears that subjects with osteoarthritis utilize gait velocity as a mechanism to reduce compressive knee joint reaction forces.RelevanceAn understanding of compressive knee joint reaction forces is important to the understanding of the disabling effects of knee osteoarthritis on physical function and to the understanding of appropriate and safe interventions to improve not only global parameters (e.g., pain, gait velocity), but also to "re-program" the locomotor pattern to develop "normal" muscle moments without increasing compressive knee joint reaction forces to painful levels.     

健康人群及关节疾病患者步态分析中时间-距离、力学及运动学和动态肌电参数的变化

背景: 步态分析可将矫形外科检查和康复治疗中沿用已久的定性分析和直观描述转换为客观、精确的定量评定。目的: 观测健康人群和患有脊柱及髋、膝、踝关节疾病患者步态分析中的时间- 距离参数、运动学参数、力学参数和动态肌电参数。设计: 对比观察, 对照实验。对象: 选择 2004- 12/2005- 07 上海交通大学附属第六人民医院康复医学科手术和康复治疗的 112 例患有脊柱及髋、膝、踝关节疾病手术或非手术治疗的患者。男性 42 例, 年龄(46±2) 岁; 女性 70 例, 年龄(41±4)岁。其中颈椎病患者 21 例, 腰椎间盘突出症及腰椎管狭窄症 26 例, 髋关节( 包括全髋关节置换术) 、膝关节( 包括前十字韧带重建术、全膝关节置换术) 、踝关节( 包括马蹄内翻足) 疾病分别 12, 34, 19 例。同期选择 40名健康志愿者( 均为上海交通大学附属第六人民医院员工) 为对照组, 年龄 20￣40 岁。纳入对象均对观测指标知情同意。方法: 应用三维步态分析系统( 英国 VICON 公司制, V- 612) 对 40 名健康志愿者和 112 例患有脊柱及髋、膝、踝关节疾病患者进行步态分析。主要观察指标: 受试者行走中的时间- 距离参数( 步长、步速、步频) 、下肢各关节运动学参数( 髋、膝、踝关节冠状轴角度) 、下肢各关节生物力学参数( 髋、膝、踝关节应力垂直轴分力) 及动态肌电参数( 股外侧肌表面肌电信号) 的变化。结果: 健康者 40 名和脊柱及下肢各关节疾病患者 112 例均进入结果分析。①时间- 距离参数: 脊柱疾病、髋关节疾病、膝关节疾病、踝关节疾病患者步频、步长、步速均明显低于 / 慢于对照组(P < 0.05￣0.01) 。②下肢各关节运动学参数及生物力学参数: 左侧前十字韧带重建术后 1 年患者支撑相初期左膝伸膝较右膝下降 9°, 支撑相初期左膝关节应力较右膝关节明显下降; 左侧全髋关节成形术术后 1 年患者支撑相初期左髋屈髋较右髋下降 8.5°, 支撑相末期伸髋下降 3°,支撑相左髋关节应力较右髋关节应力明显下降; 左足马蹄内翻患者支撑相初期左踝背屈较右踝下降12°, 支撑相末期跖屈下降 5°, 支撑相左踝关节应力较右踝关节明显下降。健康人群双侧膝关节活动度及膝关节应力垂直轴分力差异不明显。③动态肌电参数: 左侧全膝置换术后 1 年左侧股外侧肌表面肌电信号较右侧明显减弱。结论: 三维步态分析对矫形外科疾病手术方案制定及术后疗效评价、康复疗效评价及康复治疗方案制定提供切实可行的依据。     

The effect of insufficient quadriceps strength on gait after anterior cruciate ligament reconstruction.

OBJECTIVE: To determine the effect of quadriceps strength and joint stability on gait patterns after anterior cruciate ligament injury and reconstruction. DESIGN: Cross-sectional comparative study in which four groups underwent motion analysis with surface electromyography. BACKGROUND: Individuals following anterior cruciate ligament rupture often demonstrate reduced knee angles and moments during the early stance phase of gait. Alterations in gait can neither be ascribed to instability nor to quadriceps weakness alone when both are present. METHODS: Twenty-eight individuals with complete anterior cruciate ligament rupture (10 patients with acute rupture, 8 patients following reconstruction with quadriceps strength >90% of the uninvolved side [strong-anterior cruciate ligament reconstructed group], and 10 patients after reconstruction with quadriceps strength <80% of the uninvolved side [weak-anterior cruciate ligament reconstructed group]), and 10 uninjured subjects underwent an examination of their lower extremity to collect kinematics, kinetics, and electromyography during walking and jogging. Anterior cruciate ligament reconstruction was arthroscopically assisted and a double loop semitendinosis-gracilis autograft or allograft was used as a graft source. All reconstructed subjects had stable knees, full range of motion, and no effusion or pain at the time of testing (more than three months after surgery). RESULTS: Knee angles and moments of the strong group were indistinguishable from the uninjured group during early stance of both walking and jogging. The weak subjects had reduced knee angles and moments during walking, and jogged similarly to the deficient subjects. Regression analysis revealed a significant effect between early stance phase knee angles and moments and quadriceps strength during both walking and jogging. CONCLUSION: Inadequate quadriceps strength contributes to altered gait patterns following anterior cruciate ligament reconstruction. RELEVANCE: Rapid strengthening following anterior cruciate ligament injury or reconstruction may contribute to a safe return to high-level activities.     

Examining outcomes from total knee arthroplasty and the relationship between quadriceps strength and knee function over time

BACKGROUND: Temporal-spatial gait parameters improve following total knee arthroplasty (TKA) but lower limb kinematics and moments fail to match those of age-matched healthy individuals. The aim of this study was to determine whether quadriceps strength, clinical measures of knee function, lower limb kinematics, and joint moments improve following arthroplasty and normalize over time. METHODS: Twelve patients underwent total knee arthroplasty were tested at 3 and 12 months following surgery. Twelve matched controls were also tested. All underwent quadriceps strength testing and gait analysis to calculate knee joint kinematics and kinetics. Function was assessed using clinical tests and self-report. FINDINGS: All clinical measures except for quadriceps strength significantly improved from 3 to 12 months. Gait asymmetry was observed at 3 months (lower stance times, peak knee flexion angle, range of motion and vertical ground reaction force), but ankle, knee and hip moments contributing to the total limb support moment were equivalent between legs. At 12 months, gait speed remained significantly slower than controls. Inter-limb differences in peak knee flexion angle and range of motion persisted. Greater hip and lower knee moments were evident in the operated limb, compared to the non-operated limb and controls. Quadriceps strength was positively correlated with faster times on the Time Up and Go and Stair Climbing Test and greater distances during the 6 Minute Walk test. INTERPRETATION: Patients who have undergone TKA demonstrate improvements in function as measured by self-report and functional performance measures. Gait becomes more symmetric and quadriceps strength becomes stronger. Some approached the values of healthy control subjects. Important differences still remain however. The larger hip extensor contribution to the total support moment may be to compensate for the diminished knee extensor contribution during level walking. Since instrumented gait analysis and functional performance measures appear to reflect different aspects of recovery following total knee replacement, both should be considered when evaluating gait and function.     

脑卒中偏瘫患者膝过伸步态运动学特点分析

目的:探讨脑卒中偏瘫患者膝过伸步态的三维运动学特点及其与步行速度的相关性,从运动学角度探讨影响膝过伸患者步行速度的主要因素。方法:利用三维步态分析系统对15例伴有膝过伸步态的脑卒中偏瘫患者和15例健康老年人进行运动学定量比较,并将其与步行速度进行相关性分析。结果:与正常对照组相比,膝过伸患者的步长、步频减小,步速减慢,支撑期百分比延长(均P0.05);膝过伸患者髋、膝、踝关节活动范围减小,最大伸髋、屈膝、踝背屈角度减小,最大伸膝角度增加(均P0.05)。步行速度与步频、支撑相百分比、膝踝关节活动范围、最大屈膝角度和最大踝跖屈角度均相关(均P0.05)。结论:脑卒中偏瘫膝过伸患者下肢关节活动不同程度受限,步行速度下降,其中屈膝和踝跖屈异常是影响膝过伸患者步行速度的主要因素。     

Pelvic and lower limb compensatory actions of subjects in an early stage of hip osteoarthritis

OBJECTIVE: To determine if compensatory actions take place at the pelvis and other joints of the affected lower limb in subjects who were in an early stage of hip osteoarthritis (OA). DESIGN: Nonrandomized, case-control study. SETTING: A gait laboratory. PARTICIPANTS: Seventeen patients with OA of the hip (clinical group) matched with 17 healthy elderly subjects (nonclinical group). INTERVENTIONS: Video data obtained while subjects walked a 10-meter walkway twice and stepped across a forceplate. MAIN OUTCOME MEASURES: Four phasic and temporal gait parameters (walking speed, stance phase relative duration, stride length, cadence) 10 pelvic (pelvic tilt, obliquity, rotation at push-off maximum range of motion for all 3) and hip (3 hip angles at push-off, maximum hip flexion) kinematic parameters, 3 hip moments, and twenty-seven 3-dimensional peak muscle powers (labeled by joint, peak power, plane) developed in the lower limb joints during the gait cycle. RESULTS: Subjects in the clinical group were characterized by a 12.4% slower walking speed. The pelvis was more upwardly tilted (2.5 times) at push-off in the clinical group than in the nonclinical group. Obliquity, measured in the frontal plane, revealed that the pelvis dropped more (2.4 times) on the unsupported limb of the clinical group at push-off. In the sagittal plane, subjects in the clinical group absorbed less energy in their second hip peak power for decelerating the thigh extension and generated less hip pull (third hip peak power) than the nonclinical group by 34% and 29%, respectively. In the sagittal plane, the clinical group had 57% lower second knee peak power to straighten the joint shortly after heel strike, and 43% less knee absorption (third peak power) at push-off. During the push-off phase, the clinical group developed more than twice their third peak knee power in the frontal plane and 5 times more their third peak knee power in the transversal plane than the peak knee power of the nonclinical group in an attempt to control knee adduction and to facilitate body-weight transfer by an internal rotation. At the end of the swing phase, the fourth peak power in the sagittal plane showed the absorption power required to decelerate the leg; it was reduced by 35% in the clinical group, representing a strategy to increase walking speed by lengthening the stride length. CONCLUSIONS: Even at an early stage of hip OA, joint degeneration was compensated by an increase in pelvis motion and muscle power generation or absorption modifications in other lower limb joints.     

Hemiplegic gait of stroke patients: the effect of using a cane.

OBJECTIVE: To assess the effects of cane use on the hemiplegic gait of stroke patients, focusing on the temporal, spatial, and kinematic variables. DESIGN: Case-control study comparing the effect of walking with and without a cane using a six-camera computerized motion analysis system. SETTING: Stroke clinic of a tertiary care hospital. PARTICIPANTS: Fifteen ambulatory stroke patients were analyzed, including 10 men and 5 women (mean age, 56.9 years; mean time since stroke, 9.8 weeks). Nine age-matched healthy elderly subjects were recruited as a control group. RESULTS: Stroke patients walking with a cane showed significantly increased stride period, stride length, and affected side step length, as well as decreased cadence and step width (p < .05) in comparison with those who walked without a cane. There were no significant differences in the gait phases and the five gait events of hemiplegic gait walking with or without a cane. Cane use thus may have more effect on spatial variables than on temporal variables. The affected-side kinematics of hemiplegic gait with a cane showed increased pelvic obliquity, hip abduction, and ankle eversion during terminal stance phase; increased hip extension, knee extension, and ankle plantar-flexion during preswing phase; and increased hip adduction, knee flexion, and ankle dorsiflexion during swing phase as compared with hemiplegic gait without a cane. A cane thus improved the hemiplegic gait by assisting the affected limb to smoothly shift the center of body mass toward the sound limb and to enhance push off during preswing phase. It also improved circumduction gait during swing phase. CONCLUSION: Stroke patients walking with a cane demonstrated more normal spatial variables and joint motion than did those without a cane.     

Gait patterns of transtibial amputee patients walking indoors barefoot

OBJECTIVE: To evaluate the gait patterns of lower limb amputee patients walking with and without shoes and to identify differences in barefoot gait patterns when using different prosthetic feet. DESIGN: Optoelectronic three-dimensional motion analysis of gait was performed on six transtibial amputees using a solid ankle cushion heel foot and a single-axis foot, both with and without shoes. RESULTS: Gait abnormalities were observed during barefoot walking when the solid ankle cushion heel foot was used. These included knee joint hyperextension of 9.9 +/- 2.0 degrees and the loss of ankle plantar flexion in the early stance phase. When the single-axis foot was used, knee flexion thrust declined from 9.9 +/- 3.7 degrees to 7.2 +/- 3.8 degrees and ankle plantar flexion decreased from 9.9 +/- 2.8 degrees to 7.0 +/- 2.1 degrees during the early stance phase. CONCLUSIONS: In transtibial amputees, significant gait abnormalities were observed during barefoot walking using the solid ankle cushion heel foot. These gait patterns improved, however, with use of a single-axis prosthetic foot, which permits a further plantar flexion after the initial contact.     

Age-related changes in strength, joint laxity, and walking patterns: are they related to knee osteoarthritis?

BACKGROUND AND PURPOSE: Aging is associated with musculoskeletal changes and altered walking patterns. These changes are common in people with knee osteoarthritis (OA) and may precipitate the development of OA. We examined age-related changes in musculoskeletal structures and walking patterns to better understand the relationship between aging and knee OA. METHODS: Forty-four individuals without OA (15 younger, 15 middle-aged, 14 older adults) and 15 individuals with medial knee OA participated. Knee laxity, quadriceps femoris muscle strength (force-generating capacity), and gait were assessed. RESULTS: Medial laxity was greater in the OA group, but there were no differences between the middle-aged and older control groups. Quadriceps femoris strength was less in the older control group and in the OA group. During the stance phase of walking, the OA group demonstrated less knee flexion and greater knee adduction, but there were no differences in knee motion among the control groups. During walking, the older control group exhibited greater quadriceps femoris muscle activity and the OA group used greater muscle co-contraction. DISCUSSION AND CONCLUSION: Although weaker, the older control group did not use truncated motion or higher co-contraction. The maintenance of movement patterns that were similar to the subjects in the young control group may have helped to prevent development of knee OA. Further investigation is warranted regarding age-related musculoskeletal changes and their influence on the development of knee OA.     

Gait performance with compensatory adaptations in stroke patients with different degrees of motor recovery

OBJECTIVE: Gait patterns vary among stroke patients. This study attempted to discover gait performance with compensatory adaptations in stroke patients with different degrees of motor recovery. DESIGN: Data were gathered from 35 stroke patients and 15 healthy subjects. Gait performance and motor recovery were assessed 6 mos after stroke. Stroke patients further were divided into poor and good groups. The walking velocity was correlated with Brunnstr?m's stages, and the temporal stride and motion variables of the two groups were compared. RESULTS: Walking velocity was positively correlated with the Brunnstr?m's stages of the proximal lower limb. The poor group displayed slower walking velocity and shorter single-support time compared with the good group. Both groups displayed low maximum excursion of hip extension and ankle plantarflexion during the stance phase and low maximum excursion of hip and knee flexion and ankle dorsiflexion during the swing phase. Moreover, both groups displayed excessive pelvic tilts during the stance and swing phases. However, the poor group displayed different pelvic motion and timing sequences to each peak joint angle from normal subjects and the good group. Peak hip and knee angles of the affected limb during the stance phase occurred almost simultaneously in this group. CONCLUSIONS: Selective control of the proximal lower limb may be the main determinant of walking velocity. The compensatory adaptations were similar, except for pelvic motion, in stroke patients with different levels of motor recovery, whereas the poor group walked with synergistic mass patterns and reduced stability.     

Effects of laterally wedged insoles on knee and subtalar joint moments

OBJECTIVE: To assess the biomechanic effects of wearing a lateral wedge on the knee joint varus moment during gait in elders with and without knee osteoarthritis (OA). DESIGN: Crossover design whereby subjects walked under 2 different insole conditions: a 0 degrees control wedge and a 6 degrees lateral wedge. SETTING: A gait laboratory with 3-dimensional motion analysis and force platform equipment. PARTICIPANTS: Thirteen healthy subjects and 13 knee patients with OA. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Frontal plane angles and moments at the knee and subtalar joints, ground reaction forces, and center of pressure. Moments were derived by using a 3-dimensional inverse dynamics model of the lower extremity. RESULTS: The 6 degrees lateral wedge significantly reduced knee joint varus moment and increased subtalar joint valgus moment in both groups when compared with no wedge. All patients had a greater knee joint varus moment with a similar subtalar joint valgus moment compared with the people without OA. There were diverse, sometimes reversed effects with the insole among the patients. CONCLUSIONS: The 6 degrees lateral wedge did not consistently reduce the knee joint varus moment in patients with knee OA. The biomechanic indications and limitations of laterally wedged insoles should be confirmed by a larger study.     

Compensatory advantages of toe walking

OBJECTIVES: The study's hypothesis is that toe walking requires less peak muscle strength distally about the ankle and knee compared with normal heel-toe walking and thus may have compensatory advantages for patients with upper motor neuron injury and distal muscle weakness. DESIGN: Motion analysis and force platform data were collected in able-bodied subjects during toe walking and normal walking. Sagittal plane joint torques reflecting muscle force requirements and joint powers reflecting nonisometric muscle contraction were compared between the two conditions using paired t tests, applying a Bonferroni correction for multiple comparisons. SETTING: A gait laboratory. SUBJECTS: Seventeen able-bodied adults, 9 of whom were ballet dancers. MAIN OUTCOME MEASURES: Peak hip, knee, and ankle joint torque and power variables during walking. RESULTS: Peak ankle plantarflexor torque and ankle power generation during terminal stance and preswing were reduced (p<.001), as compared with normal heel-toe walking. The normal ankle dorsiflexor torque at initial contact-and the knee extensor torque and knee power generation during loading response were all essentially absent during toe walking. Hip extensor torque and hip power generation during the loading response phase were greater for toe walking (p<.001). CONCLUSION: Toe walking may require less ankle plantarflexor, ankle dorsiflexor, and knee extensor strength than normal heel-toe walking and thus may have compensatory advantages for patients with upper motor neuron injury and distal lower extremity weakness.     

The effect of total knee replacement on dynamic support of the body during walking and stair ascent

BACKGROUND: Little is known about the effects of total knee replacement surgery on the contributions of individual joint moments to the total support moment. A better understanding of these effects may enhance rehabilitation protocols and determine factors related to long-term surgical outcome. METHOD: Twenty-one subjects with total knee replacement and 21 controls performed level walking and stair ascent at two testing periods, pre- and 6 months post-surgery. Variables studied included gait velocity, stride length, knee flexion angle, net joint moments of the hip, knee and ankle, and total support moment. Data were analyzed at the first peak vertical ground reaction force. FINDINGS: For level walking, the total support moment, knee extensor moment, and knee flexion angle of total knee replacement patients were less than controls at post-surgery. For stair ascent, the patient group total support moment, ankle plantarflexor moment, and knee flexion angle were less than controls at both testing periods, while knee extensor moment was less than controls at post-surgery. Extensor synergies of the total knee replacement patients revealed less knee and more hip contributions during level walking and larger hip contributions during stair ascent to the total support moment than controls at both testing periods. INTERPRETATION: A feature of total knee replacement gait, pre- and post-surgery, is a stiff knee attitude which may serve to protect the quadriceps. The larger hip extensor contribution to the total support moment observed in the patients may compensate for the diminished knee extensor contribution during level walking and stair ascent.     

A new approach to detecting asymmetries in gait

BACKGROUND: Traditional parameters used to assess gait asymmetries, e.g., joint range of motion or symmetry indices, fail to provide insight regarding timing and magnitude of movement deviations among lower limb joints during the gait cycle. This study evaluated the efficacy of a new approach for quantifying aspects of gait asymmetry. METHODS: Asymmetric gait was simulated by joint bracing. The dominant leg knee or ankle was constrained in ten healthy young adult males. Kinematic data were collected during three-minute trials for treadmill-walking conditions: unbraced, knee-braced, and ankle-braced. We created a regions of deviation analysis, which compared asymmetric walking (flexion/extension behavior) relative to normative (group-averaged unbraced) data. Symmetry/asymmetry between bilateral joint pairs was quantified and the behavior of specific joints relative to normative data was assessed using this analysis. FINDINGS: While traditional measures (e.g., maximum range of motion) grossly detected asymmetries due to bracing, these new analyses identified significant regions of asymmetry. Knee-bracing affected the knee during mid-swing, but also increased ankle asymmetry during both terminal stance and mid-swing and hip asymmetry during mid-stance and mid-swing. Ankle-bracing created asymmetries at the ankle (terminal stance and initial swing) and hip (terminal stance), but none at the knee. INTERPRETATION: Region of deviation analysis effectively identified the timing and magnitude of deviations throughout the gait cycle, and provided information about the impact of a joint-mobility perturbation on neighboring joints. This new methodology will be useful in clinical settings to identify, characterize, and monitor recovery from asymmetric behaviors associated with injuries or pathologies.     

单侧小腿截肢患者穿假肢后的步态运动学参数研究

目的 采用计算机辅助康复环境(CAREN)步态评估系统分析单侧小腿截肢患者穿假肢后的步态运动学参数,并分析其产生差异的原因。 方法 选取单侧小腿中段截肢但均装配假肢的受试者9例设为假肢组,同期选择健全受试者11例设为标准组,通过CAREN步态评估系统对2组受试者的步态运动学参数进行收集、处理、分析,并根据分析报告阐明产生差异原因。 结果 假肢组步态时相性指数为(0.88±0.04),其假肢侧的步长、支撑期百分比、髋关节支撑期最大伸展角度、膝关节支撑期最大屈曲角度、踝关节足跟着地背屈角度、踝关节支撑期最大背屈角度、踝关节支撑期最大跖屈角度与健侧比较,差异均有统计学意义(P<0.05）。假肢组假肢侧的步行速度、步态周期、跨步长、支撑期百分比、髋关节足跟落地屈髋角度、髋关节支撑期最大伸展角度、髋关节支撑期最大屈曲角度、膝关节足跟着地屈膝角度、踝关节足跟着地背屈角度、踝关节支撑期最大跖屈角度、踝关节支撑期最大背屈角度与标准组双侧均值比较,差异均有统计学意义(P<0.05）。 结论 单侧小腿截肢者穿戴假肢后步态时相对称性为（0.88±0.04）,假肢侧踝关节运动学参数显著弱于自身健侧,其时空与运动学参数也显著弱于健全人。     

脑卒中患者步行能力与下肢三维运动学及动力学相关性分析

目的:通过对脑卒中偏瘫患者下肢三维运动学和动力学的分析,寻找偏瘫患者步态特点,比较分析步行能力与运动学和动力学之间的关系,从运动力学角度探讨偏瘫患者异常步行的原因,寻找康复治疗中需解决的关键问题。方法:选择首次脑卒中后可以独立步行10m以上的右侧偏瘫患者20例为实验组,正常健康中老年人16例为对照组。采用Vicon和AMTOR6-7进行三维步态运动学和动力学检测和分析。结果:实验组与正常对照组比较,脑卒中患者与健康中老年人在步频、跨步时间、双腿支撑时间、步时、离地比率、步长、跨步长和步速同侧比较差异有显著性意义(P<0.05),患侧离地占步态周期百分比和健侧单腿支撑时间实验组与对照组比较差异有显著性意义(P<0.05)。矢状面上同侧髋关节伸展角度、膝关节屈曲角度和踝关节背伸及跖屈角度比较差异都有显著性意义(P<0.05)。同侧髋关节屈伸力矩、同侧膝关节伸直力矩和患侧踝关节背伸力矩实验组和对照组相比差异有显著性意义(P<0.05),步行能力(步速)与患侧髋关节伸展、健侧膝关节屈曲、双侧膝关节伸展、双侧踝关节背伸和跖屈角度相关,均有显著性意义(P<0.05);同时也和双侧髋关节屈伸、膝关节伸展和踝关节背伸力矩相关(P<0.01)。结论:①步长是脑卒中偏瘫患者步态异常的重要参考指数;②髋关节和膝关节伸展,踝关节背伸和跖屈是步态异常的重要表现;③下肢髋关节和膝关节屈伸肌群和踝关节背伸肌群的力量是影响步行能力的重要因素。