Osteoarthritis Walk Research Articles

Effectiveness of Ultrasound with Isometric Quadriceps Exercise and Retro walking in Osteoarthritis

Introduction: Knee osteoarthritis is a non-inflammatory, painful and degenerative joint disease; pathologic changes in osteoarthritis involve progressive hyaline joint cartilage loss with concomitant changes in subchondral bone and development of osteophyte. About symptomatic knee osteoarthritis affect 13% of women and 10% of men aged 60 years and older. Men have a lower prevalence of knee osteoarthritis than women. The tool used to measure pain intensity, physical functions in this study is WOMAC scale and to assess the range of motion by Universal goniometer. Aim : To Evaluate the Effectiveness of Ultrasound with Isometric quadriceps exercise and retro walking in osteoarthritis of knee. Method : A Total 30 both male and female participants between 45 to 65 years of age selected from RJS Group of institute of kopargaon , Kothari hospital kopargaon by using purposive sampling method according to the inclusion criteria. The total duration of the study is 3 weeks .total 30 participants allocated into two groups A and B 15 in each group. In group A were intervention Ultrasound with isometric quadriceps exercise and group B Ultrasound with retro walking were given for 3 weeks. Pre intervention and post intervention by WOMAC score and universal goniometer were taken analyzed compared using paired’ test. RESULT: As per statistical analysis both groups shown significant improvement but group B ( Ultrasound with Retro walking )was having most significant improvement as compare to group A ( Ultrasound with Isometric quadriceps exercises). CONCLUSION : This study concluded that Ultrasound with Retro walking was effective in participants with Osteoarthritis of knee .Hence there is reduction of pain, improving range of motion at knee joint and functional mobility, Activity of daily living in participants with osteoarthritis of knee.

Association of mechanical temporal summation of pain with muscle co-contraction during walking in people with knee osteoarthritis

BackgroundPeople with knee osteoarthritis walk with excessive muscle co-contraction that can accelerate disease progression. Central pain sensitization is common in people with knee osteoarthritis and may be related to walking patterns. The objective of this study was to examine the relation of central pain sensitization with muscle co-contraction during walking in people with knee osteoarthritis. MethodsThis study reports secondary analysis from baseline data of two clinical trials (n = 90 participants with knee osteoarthritis). The presence of central pain sensitization was measured by mechanical temporal summation at the patella and the wrist. Quadriceps and hamstrings activation was assessed using surface electromyography during walking at self-selected and fast paces. Muscle co-contraction indices for vastus medialis-medial hamstrings and vastus lateralis-lateral hamstrings muscle pairs were calculated during stance phases. Co-contraction outcomes were compared between people with and without mechanical temporal summation at each site, adjusting for age, sex, and body mass index. FindingsPeople with mechanical temporal summation at the knee had greater vastus lateralis-lateral hamstrings co-contraction while walking at a fast pace (P = 0.04). None of the other differences was statistically significant, but the overall trends and effect sizes indicated greater co-contraction in people with temporal summation at the knee irrespective of gait phase, walking speed, or muscle pairs. InterpretationCentral pain sensitization, assessed as mechanical temporal summation at the knee, is related to greater knee muscle co-contraction during fast walking in people with knee osteoarthritis. Thus, mitigating central sensitization may be an interventional target to reduce muscle co-contraction for people with knee osteoarthritis.

Knee adduction moment decomposition: Toward better clinical decision-making.

Knee adduction moment (KAM) is correlated with the progression of medial knee osteoarthritis (OA). Although a generic gait modification can reduce the KAM in some patients, it may have a reverse effect on other patients. We proposed the "decomposed ground reaction vector" (dGRV) model to 1) distinguish between the components of the KAM and their contribution to the first and second peaks and KAM impulse and 2) examine how medial knee OA, gait speed, and a brace influence these components. Using inverse dynamics as the reference, we calculated the KAM of 12 healthy participants and 12 patients with varus deformity and medial knee OA walking with/without a brace and at three speeds. The dGRV model divided the KAM into four components defined by the ground reaction force (GRF) and associated lever arms described with biomechanical factors related to gait modifications. The dGRV model predicted the KAM profile with a coefficient of multiple correlations of 0.98 ± 0.01. The main cause of increased KAM in the medial knee OA group, the second component (generated by the vertical GRF and mediolateral distance between the knee and ankle joint centers), was decreased by the brace in the healthy group. The first peak increased, and KAM impulse decreased with increasing velocity in both groups, while no significant change was observed in the second peak. The four-component dGRV model successfully estimated the KAM in all tested conditions. It explains why similar gait modifications produce different KAM reductions in subjects. Thus, more personalized gait rehabilitation, targeting elevated components, can be considered.

Do individuals with knee osteoarthritis walk with distinct knee biomechanics and muscle activation characteristics? An investigation of knee osteoarthritis, hip osteoarthritis, and asymptomatic groups

BackgroundBiomechanical markers including reductions in sagittal plane kinematics and moments, increases in knee adduction moments (KAM), and altered muscle activations have been identified as hallmark indicators of knee osteoarthritis (OA). However, it remains unknown whether these features of knee OA gait are exclusive to the diseased joint. Research questionTo determine whether specific gait outcomes previously linked to symptomatic medial compartment knee OA are unique to knee OA by concurrently investigating a group of asymptomatic individuals and those with hip OA. Methods16 individuals with moderate medial compartment knee OA, 16 individuals with moderate hip OA, and 16 asymptomatic controls were recruited. Participants walked on a treadmill while segment kinematics and ground reaction forces were recorded. Sagittal plane kinematics and sagittal and frontal plane moments were calculated. Surface electromyograms were recorded from lateral and medial hamstrings and gastrocnemius and vastus lateralis and medialis. Discrete variable analysis was used to investigate knee joint mechanics and muscle activation ratios. Analysis of Variance models using Bonferroni corrections determined between group differences (α = 0.0167). ResultsSagittal plane knee kinematics and moments were statistically similar among all groups (p > 0.0167). No differences were found for peak KAM and impulse between knee OA and asymptomatic groups (p > 0.0167) but peak KAM (p = 0.006 and impulse (p = 0.001) were greater in the knee OA group compared to hip OA. The hip OA group had a lower KAM impulse (p < 0.0167) compared to the knee OA and asymptomatic groups. A greater LH:MH activation ratio (p < 0.0167) was found in the knee OA group compared to hip OA and asymptomatic groups. No other activation ratio differences were found (p > 0.0167). SignificanceMedial and lateral hamstring muscle activation levels may provide utility as a knee OA gait biomarker compared to biomechanical outcomes, quadriceps and gastrocnemius activation, when differentiating knee OA from asymptomatic and hip OA cohorts.

Individuals with mild-to-moderate hip osteoarthritis walk with lower hip joint contact forces despite higher levels of muscle co-contraction compared to healthy individuals

To compare hip joint contact forces (HJCF), hip muscle forces, and hip muscle co-contraction levels between individuals with mild-to-moderate hip osteoarthritis (OA) and healthy controls during walking. Eighteen participants with mild-to-moderate hip OA and 23 healthy controls walked at a self-selected speed while motion capture and electromyographic data were synchronously collected. HJCF were computed using a calibrated electromyography-informed neuromusculoskeletal model. Hip joint contact forces, muscle forces, and co-contraction indices for flexor/extensor and adductor/abductor muscle groups were compared between groups using independent sample t-tests (P<0.05). There was no between-group difference in self-selected walking speed. On average, participants with hip OA walked with 11% lower first peak (mean difference 235 [95% confidence interval (CI) 57-413] N) and 22% lower second peak (mean difference 574 [95%CI 304-844] N) HJCF compared to controls. Hip muscle forces were also significantly lower in the hip OA compared to control group at first (mean difference 224 [95%CI 66-382] N) and second (mean difference 782 [95%CI 399-1164] N) peak HJCF. Participants with hip OA exhibited higher levels of hip muscle co-contraction in both flexor/extensor and adductor/abductor muscle groups. Consistent with existing literature, hip joint angles (extension, adduction) and external moments (flexion, extension, adduction) were lower in hip OA compared to controls. Lower HJCF were detected in mild-to-moderate hip OA, primarily due to lower hip muscle force production, and despite higher levels of hip muscle co-contraction. Findings suggest that lower loading of the hip joint during walking is a feature of mild-to-moderate hip OA, which could have implications for the pathogenesis of hip OA and/or disease progression.

Association of walking cadence with knee adduction angular impulse while controlling for speed in patients with knee osteoarthritis

Purpose: Walking cadence and speed are correlated and may affect knee loading in different ways. Previous research suggests higher walking cadence at baseline is associated with less structural progression of knee osteoarthritis (OA), presumably due to lower cumulative knee loading. The knee adduction angular impulse during walking is a surrogate measure of medial compartment load throughout stance and is associated with greater knee OA progression and knee pain. Thus, we aimed to test the hypothesis that higher walking cadence is associated with lower knee adduction angular impulse, while controlling for walking speed, in patients with medial knee OA. Methods: We analyzed existing data from 691 patients with medial compartment knee OA and varus alignment who participated in studies investigating rehabilitative and surgical interventions. The mean age and body mass index were 47±9 years and 30±5 kg/m2, respectively. All patients had undergone a baseline 3D quantitative gait analysis at preferred walking speed and cadence. Analyses included spatiotemporal characteristics and external knee joint moments. We used multivariate linear regression to test the association of cadence with knee adduction angular impulse while controlling for walking speed. We repeated the regression analyses while sequentially replacing the dependent variable knee adduction angular impulse with the first peak knee adduction moment, second peak knee adduction moment, peak knee flexion moment and peak vertical ground reaction force. We also repeated these analyses separately for females (n=163) and males (n=528). Lastly, we split the cohort into higher (n=462) and lower (n=229) cadence groups based on a cut-point of 100 steps/min - the minimum recommended walking cadence for adults - and plotted their adjusted means using analysis of covariance controlling for walking speed. Results: Mean ± SD for cadence, speed and knee adduction angular impulse were 1.10±0.19 m/s, 103±10 steps/min, 1.59±0.56 %BW.Ht.s; respectively. While controlling for walking speed, cadence was negatively associated with knee adduction angular impulse (unstandardized B [95% CI], p-value = -0.020 [-0.027 to -0.015], p<0.001), suggesting every 1 step/min increase in cadence was associated with a 0.02 %BW.Ht.s decrease in knee adduction angular impulse. For example, an increase in cadence of 20 steps/min (e.g. from 100 to 120 steps/min) was associated with a decrease in knee adduction angular impulse of 0.4 %BW.Ht.s (e.g. from 1.6 to 1.2 %BW.Ht.s), and when described in terms of the percent changes from the present sample means, this translated to a 20% increase in cadence associated with a 25% decrease in knee adduction angular impulse. The association was slightly higher in females (-0.028 [-0.039 to -0.016], p<0.001) than males (-0.017 [-0.024 to -0.009], p<0.001). While controlling for walking speed, cadence was also negatively associated with other surrogate measures of knee loading (Table 1). Adjusted means for higher and lower cadence groups are shown in Figure 1, illustrating that patients with medial knee OA walking with higher cadence (109±6 steps/min) have lower knee adduction angular impulse than patients walking at the same speed but with lower cadence 92±7 steps/min) (adjusted knee adduction angular impulse mean difference [95% confidence interval]: -0.27 %BW.Ht.s [-0.37 to -0.16]). Conclusions: In patients with medial knee OA, when controlling for walking speed, higher walking cadence is associated with lower knee adduction angular impulse. Although lower in size, the negative association of cadence remained with other surrogate measures of knee loading while controlling for walking speed. Future prospective studies should investigate the hypothesis that gait retraining to increase cadence at a given walking speed has beneficial biomechanical and clinical effects in patients with knee OA.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Individuals with mild-to-moderate hip osteoarthritis walk with lower hip joint contact forces despite higher levels of muscle co-contraction compared to healthy controls

Purpose: Conservative non-pharmacological interventions are recommended for the clinical management of hip osteoarthritis (OA), though no existing treatments can modify structural disease progression. Evidence-based treatment targets are required to inform the development of disease-course altering interventions. Abnormal hip joint loading is potentially modifiable (e.g. gait and/or neuromuscular retraining) and may play an important role in hip OA progression. No previous study has investigated whether individuals with mild-to-moderate hip OA exhibit altered hip joint contact forces (HJCF) during gait, or identified any relevant contribution of altered hip muscle co-contraction to hip joint loading in this patient population. This study aimed to compare: (1) HJCF between individuals with mild-to-moderate hip OA and healthy controls during walking using an electromyography (EMG)-informed modelling approach; and (2) hip muscle co-contraction levels between groups. Methods: Eighteen participants (age=65±7 yrs; body mass index=27.6±4.8 kg.m-2; 72% females) with mild-to-moderate hip OA and 23 healthy controls without hip pain or radiographic hip OA (age=60±8 yrs; body mass index=25.1±4.8 kg.m-2; 74% females) performed 10 over-ground walking trials at a self-selected speed. Three-dimensional lower-body motion, ground reaction forces, and surface EMG from sixteen lower-limb muscles were synchronously acquired.Hip joint contact forces were solvedby balancing the external joint moments with internal muscle forces estimated using a calibrated EMG-informed neuromusculoskeletal model. Hip muscle contributions and co-contraction ratios (abduction/adduction and flexion/extension) were determined. Demographic, spatiotemporal, and primary outcome measures were compared between groups using independent t-tests. A secondary analysis of HJCF peaks was performed usingaone-way analysis of covariance with body mass index as a covariate (p<0.05). Results: Height, body mass, body mass index, and walking speed did not differ between groups. Participants with hip OA walked with an 11% lower first peak (p=0.01) and 28% lower second peak (p<0.01) HJCF compared to controls (Fig. 1). Differences remained significant when adjusted for body mass index. Participants in the hip OA group exhibited higher levels of hip muscle co-contraction in both flexion/extension (p<0.01) and abduction/adduction (p=0.04) during all phases of stance compared to controls. Hip muscle forces (p<0.01), peakhip extension (p<0.01) and peak hip adduction (p=0.03) joint angles, and peak hip flexion (p=0.01) and peak hip extension (p<0.01) joint moments were also lower in the hip OA compared to control group. Conclusions: Individuals with mild-to-moderate hip OA walk with lower HJCF, despite exhibiting higher levels of hip muscle co-contraction, compared to healthy controls. These observations contradict previous assumptions regarding the effect of higher levels of muscle co-contraction on joint loading in this cohort.This is the first study to demonstrate that under-loading is characteristic of individuals with early hip OA, and may suggest that interventions aimed at reducing hip joint loading are not appropriate for this patient group. Future studies are required to evaluate the effects of under-loading on hip cartilage health, with the aim of identifying modifiable treatment targets to slow disease progression in individuals with hip OA.

Knee motion and muscle activation patterns are altered in hip osteoarthritis: The effect of severity on walking mechanics

BackgroundKnee function is impaired in individuals with moderate hip osteoarthritis. How this extends to those undergoing total hip arthroplasty is unknown despite the common requirement for knee arthroplasty in this population. The study purpose was to determine whether sagittal plane knee joint movements and quadriceps and hamstring activation patterns differ between individuals with either moderate or severe unilateral hip osteoarthritis, and between ipsilateral and contralateral knees. Methods20 individuals with moderate osteoarthritis and 20 with severe osteoarthritis were recruited. Sagittal knee motion and surface electromyograms from the hamstrings and quadriceps were collected during treadmill walking at a self-selected speed. Principal component analysis captured amplitude and temporal sagittal plane motion and EMG waveform features. Student's t-tests and Analysis of Variance determined between group differences and within/between group leg differences. FindingsThe severe groups' contralateral knee was in greater flexion at initial contact and demonstrated a movement profile of a longer stance phase (p < 0.001). The severe group had reduced sagittal plane knee motion (p < 0.0001); more so in the ipsilateral knee (p < 0.0001). The severe group had greater hamstring (p = 0.009) and quadriceps activation (p < 0.001) overall, specifically mid-stance quadriceps bilaterally (p = 0.002). Ipsilateral sagittal plane knee motion was reduced in both groups. Compared with those with moderate osteoarthritis, individuals with severe osteoarthritis walk with reduced sagittal plane knee motion bilaterally, suggesting prolonged contralateral stance, and elevated mid-stance hamstring and quadriceps activation. InterpretationAltered kinematics and muscle activity could contribute to a greater mechanical demand on the contralateral knee in those with more severe hip osteoarthritis.

Analysis of symmetry between lower limbs during gait of older women with bilateral knee osteoarthritis.

Osteoarthritis (OA) is a common condition in older adults, with high epidemiological, clinical, and economic burden worldwide. In clinical practice, patients with knee OA often walk with abnormal gait patterns because of pain, stiffness and/or mobility dysfunctions. Therefore, assessing the symmetry of the lower limbs might improve the rehabilitation treatment and prescription of walking devices. To compare the symmetry of step length and single support phase between lower limbs during gait of older women with bilateral knee OA and asymptomatic controls, and to verify if there is difference between these two groups in relation to velocity, cadence, step length and single support phase. This cross-sectional study included a convenience sample of 66 community-dwelling older women aged ≥ 65years with a medical diagnosis of symptomatic bilateral knee OA (n = 33) and asymptomatic controls (n = 33), matched by age and body mass index. All gait parameters were obtained using the GAITRite® system. Mean age of the sample was 72.6 ± 4.0years. Participants with OA walked with lower velocity (p = 0.001), cadence (p = 0.009) and step length bilaterally (both p = 0.001). No significant difference was found between groups in the symmetry of step length between lower limbs, single support phase and symmetry of single support phase between lower limbs. Older women with bilateral knee OA walk with lower velocity, cadence and step length, but have the same symmetry in the step length and single support phase between lower limbs as asymptomatic older women.

Pelvic and Hip Kinematics During Walking in People With Patellofemoral Joint Osteoarthritis Compared to Healthy Age-Matched Controls.

Patellofemoral (PF) joint osteoarthritis (OA) is common, yet little is known about how this condition influences lower-extremity biomechanical function. This study compared pelvis and lower-extremity kinematics in people with and without PF joint OA. Sixty-nine participants (64% women, mean ± SD age 56 ± 10 years) with anterior knee pain aggravated by PF joint-loaded activities (e.g., stair ambulation, rising from sitting, or squatting) and radiographic lateral PF joint OA on skyline radiographs were compared with 18 controls (78% women, mean ± SD age 53 ± 7 years) with no lower-extremity pain or radiographic OA. Knee Injury and Osteoarthritis Outcome Score (KOOS) data were collected from participants with PF joint OA. Quantitative gait analyses were conducted during overground walking at a self-selected speed. Pelvis and lower-extremity kinematics were calculated across the stance phase. Data were statistically analyzed using analyses of covariance, with age and sex as covariates (P < 0.05). Participants with PF joint OA reported a mean ± SD KOOS pain subscale score of 65 ± 15, KOOS symptoms subscale score of 63 ± 16, KOOS activities of daily living subscale score of 73 ± 13, KOOS sports/recreation subscale score of 45 ± 23, and KOOS quality of life subscale score of 43 ± 16. Participants with PF joint OA walked with greater anterior pelvic tilt throughout the stance phase, as well as greater lateral pelvic tilt (i.e., pelvis lower on the contralateral side), greater hip adduction, and lower hip extension during the late stance phase. No differences in knee and ankle joint angles were observed between groups. People with PF joint OA walk with altered pelvic and hip movement patterns compared with aged-matched controls. Restoring normal movement patterns during walking in people with PF joint OA may be warranted to help alleviate symptoms.

Muscle Activation Profiles and Co-Activation of Quadriceps and Hamstring Muscles around Knee Joint in Indian Primary Osteoarthritis Knee Patients.

Osteoarthritis (OA) of knee is a common joint disease. It is associated with reduced knee joint stability due to impaired quadriceps strength, pain, and an altered joint structure. There is altered muscle activation in knee OA patients, which interferes with normal load distribution around the knee and facilitates disease progression. Our primary aim was to determine activation patterns of the muscles i.e., quadriceps and hamstrings in knee OA patients during walking. We also studied co-activation of muscles around knee joint in primary OA knee patients including directed medial and lateral co-contractions. This observational study was done at Department of Physical Medicine and Rehabilitation, All India Institute of Medical Sciences, New Delhi, India. Fourty-four patients with medial compartment primary knee OA were included in study after satisfying inclusion and exclusion criteria. All the patients were assessed for mean, peak and integrated Root Mean Square (RMS), EMG values, muscle activation patterns and co-activation of muscles around knee joint by surface Electromyography (EMG) analysis of Vastus Medialis Obliques (VMO), Vastus Lateralis (VL), Semitendinosus (SMT) and Biceps Femoris (BF) muscles during gait cycle. The EMG waveform for each muscle was amplitude normalized and time normalized to 100% of gait cycle and plotted on graph. Quantitative variables were assessed for normal distribution and accordingly mean±SD or median (range), as appropriate, was computed. For primary OA knee, mean age 61±5 years, mean weight 63.7±10.1 kg, mean height 153.9±7.2 cm, and mean Body Mass Index (BMI) 26.8±3.0 kg/m2 was found. The muscle activity of hamstrings (SMT muscle and BF) was increased during midstance, late stance and early swing phase of gait cycle as compared to quadriceps (VMO and VL) muscle activity respectively, suggesting co-contraction of opposing muscles around knee joint. Patients with knee OA walk with increased hamstring muscle activity (during late stance and early swing phase) and reduced quadriceps recruitment. Altered neuro-muscular control around knee interferes with normal load distribution and facilitates disease progression in knee joint.

Kinematic Analysis of Human Gait Based on Wearable Sensor System for Gait Rehabilitation

Quantitative analysis of gait phases is needed for gait rehabilitation. This study proposes a wireless wearable system for real-time monitoring of plantar pressure distribution and acceleration information during walking. The goal of this paper is to investigate the potential use of the support vector machine technique with force-sensitive resistor and acceleration values to detect phases in the cyclic motion of the human dynamic gait. The device consists of a flexible insole with seven force-sensitive elements and a triaxial accelerometer that is integrated with an electronic board for high-frequency data acquisition, pre-filtering, and wireless transmission to a remote data computation and storage unit. The design and development of the device are presented, along with its experimental characterization and validation when applied to healthy participants and those diagnosed with osteoarthritis walking at various speeds, and benchmarked against an instrumented force platform. The experimental results verify that the proposed method is valid, with an accuracy of as high as 94.08%.

Asymptomatic and symptomatic individuals with the same radiographic evidence of knee osteoarthritis walk with different knee moments and muscle activity.

There is an established discordance between the structural joint damage and clinical symptoms of knee osteoarthritis; however, there has been little investigation into the differences in joint level biomechanics and muscle activation patterns during gait between symptomatic and asymptomatic individuals with the same radiographic evidence of osteoarthritis. The objective of this study was to examine three-dimensional knee joint biomechanics and muscle activation differences during gait between asymptomatic and symptomatic individuals with radiographic knee osteoarthritis. A total of 54 asymptomatic and 59 symptomatic individuals with a Kellgren-Lawrence osteoarthritis radiographic grade of 2 underwent a comprehensive gait analysis to examine differences in the magnitude and patterns of the knee flexion angle, three-dimensional net resultant moments, and electromyography of the quadriceps, hamstrings, and gastrocnemii during over ground walking between the two groups. The symptomatic group walked with significantly higher overall magnitudes and less mid-stance unloading of the net resultant knee adduction moment, lower peak flexion moments, and higher lateral hamstrings and quadriceps activity during stance than the Asymptomatic group (p < 0.05, sex-adjusted analysis), with a trend (p = 0.07) toward greater transverse plane range of moment over stance. The differences found suggest a "stiffer" frontal and sagittal plane pattern with symptomatic individuals, but with more muscle activity and a trend toward more torsional loading in the transverse plane, which may have implications for shear loading of the joint. This is the first evidence of differences in three-dimensional knee joint biomechanics and muscle activation between asymptomatic and symptomatic individuals with the same radiographic grade. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1661-1670, 2017.

Validity and test-retest reliability of the Stride Analyzer in people with knee osteoarthritis

IntroductionSubjects with knee osteoarthritis walk differently compared to healthy subjects. Managing these gait alterations has been proven effective for reducing pain and increasing function. The Stride Analyzer is a low cost gait analysis tool but its clinimetric properties have not been investigated yet in subjects with symptomatic knee osteoarthritis. The aim of this study was to investigate the reliability and validity of the SA compared with the Gold standard (Vicon) in persons with knee OA. MethodsFifteen subjects with symptomatic knee osteoarthritis were instructed to walk at a self-selected speed in a gait laboratory. Temporospatial (TS) gait parameters were recorded simultaneously by the Stride Analyzer and by a 16-camera-infrared optoelectronic motion capturing system (Vicon). Validity and test-retest reliability of the Stride Analyzer were examined by Bland-Altman plots, intra-class correlation coefficients (ICC) and the standard error of measurement (SEM). ResultsTest-retest analyses showed good agreement for all TS parameters with ICC values ranging from 0.805 (single limb support right) to 0.949 (velocity) and SEM% values ranging from 0.78% (stance phase right (% of gait cycle)) to 4.52% (double limb support right (% of gait cycle)). Good agreement between Stride Analyzer and Vicon was found for the following TS parameters: velocity (z=1.01), cadence (z=−0.85), stride length (z=1.63) and gait cycle (z=0.86). All other gait parameters showed lower ICC values (<0.689). InterpretationOur results suggest that the Stride Analyzer can be used in the clinical field to perform gait analysis in subjects with symptomatic knee osteoarthritis.

Hip joint motion and gluteal muscle activation differences between healthy controls and those with varying degrees of hip osteoarthritis during walking

Purpose: Compare gluteal muscle activation patterns and three-dimensional hip joint movements among those with severe hip osteoarthritis (OA), moderate OA and a healthy group during walking. Scope: 20 individuals with severe OA, 20 with moderate OA and 20 healthy individuals were recruited. Three-dimensional hip motion and surface electromyograms from gluteus maximus and medius were collected during treadmill walking at a self-selected speed. Angular displacement characteristics were calculated for three-dimensional hip motions. Principal component analysis extracted amplitude and temporal features from electromyographic waveforms. Analysis of Variance models and student t-tests using Bonferroni corrections determined between group differences in these gait features (α=0.05). Conclusions: Sagittal plane hip range of motion was significantly reduced with increasing severity of OA (p<0.05) where as frontal and transverse plane range of motion was reduced in the severe OA group only (p<0.05). Activation patterns of gluteus medius and maximus did not differ between the healthy group and those with moderate hip OA (p>0.05). Individuals with severe OA walking with more prolonged gluteus maximus activation and prolonged and less dynamic gluteus medius activation compared to the other two groups (p<0.05). This study highlights the changing function of the hip joint during walking with increasing hip OA severity.

분할 벨트 조건을 이용한 무릎 관절 이상군의 보행 비대칭성 모사

Walking on split-belt treadmill has been applied to study walking disabilities, such as osteoarthritis (OA), to show asymmetric walking characteristics. In this study, we compared asymmetric walking in OA patients with healthy subjects under split-belt conditions and examined the reproduction of walking asymmetry in OA. Seven OA patients were instructed to walk at four frequencies, while four healthy subjects walked on a treadmill with tied-belt and split-belt conditions. To compare walking asymmetries, kinetic and kinematic measurements were made using force-plates and motion capture cameras, and subsequently center of mass (CoM) velocity, mechanical work and potential energy were calculated. Horizontal velocity change during split-belt walking of healthy subjects was similar to OA patients. Difference of mechanical work during single support phase occurred due to fall of CoM in fast belt. OA walking asymmetry could be reproduced by reducing differences of belt speeds to prevent rapid fall of CoM.

Using impairment and cognitions to predict walking in osteoarthritis: A series of n-of-1 studies with an individually tailored, data-driven intervention.

First, this study compares the ability of an integrated model of activity and activity limitations, the International Classification of Functioning, Disability and Health (ICF), and the Theory of Planned Behaviour (TPB) to predict walking within individuals with osteoarthritis. Second, the effectiveness of a walking intervention in these individuals is determined. A series of n-of-1 studies with an AB intervention design was used. Diary methods were used to study four community-dwelling individuals with lower-limb osteoarthritis. Data on impairment symptoms (pain, pain on movement, and joint stiffness), cognitions (intention, self-efficacy, and perceived controllability), and walking (step count) were collected twice daily for 12 weeks. At 6 weeks, an individually tailored, data-driven walking intervention using action planning or a control cognition manipulation was delivered. Simulation modelling analysis examined cross-correlations and differences in baseline and intervention phase means. Post-hoc mediation analyses examined theoretical relationships and multiple regression analyses compared theoretical models. Cognitions, intention in particular, were better and more consistent within individual predictors of walking than impairment. The walking intervention did not increase walking in any of the three participants receiving it. The integrated model and the TPB, which recognize a predictive role for cognitions, were significant predictors of walking variance in all participants, whilst the biomedical ICF model was only predictive for one participant. Despite the lack of evidence for an individually tailored walking intervention, predictive data suggest that interventions for people with osteoarthritis that address cognitions are likely to be more effective than those that address impairment only. Further within-individual investigation, including testing mediational relationships, is warranted. What is already known on this subject? N-of-1 methods have been used to study within-individual predictors of walking in healthy and chronic pain populations An integrated biomedical and behavioural model of activity and activity limitations recognizes the roles of impairment and psychology (cognitions) Interventions modifying cognitions can increase physical activity in people with mobility limitations What does this study add? N-of-1 methods are suitable to study within-individual predictors of walking and interventions in osteoarthritis An integrated and a psychological model are better predictors of walking in osteoarthritis than a biomedical model There was no support for an individually tailored, data-driven walking intervention.

Spatial-Temporal Gait Characteristics in Individuals With Hip Osteoarthritis: A Systematic Literature Review and Meta-analysis

Systematic literature review and meta-analysis. To systematically review and critically evaluate the literature to determine how basic gait characteristics are altered in individuals with hip osteoarthritis (OA). Hip OA is a progressive musculoskeletal condition that leads to pain, stiffness, and functional limitation in activities such as walking. Understanding gait dysfunction in people with hip OA may contribute to more effective management of the disease. Eleven electronic research databases were searched. Studies comparing basic gait parameters in individuals with hip OA to healthy controls and the affected to the contralateral limb of individuals with hip OA were included. The studies were critically appraised for methodological quality. Available data were extracted, and meta-analysis was performed, with standardized effect sizes (Cohen d) and corresponding 95% confidence intervals computed for gait speed, cadence, step and stride length, stance, swing and double-stance duration, and step width. The final analysis included 30 articles. Self-selected gait speed was 26% slower in individuals with hip OA relative to controls, which was explained by shorter stride length. Consistent evidence was found for greater asymmetry in individuals with hip OA than controls, with shorter step length and stance duration in the affected compared to the contralateral limb. Individuals with hip OA walk at a slower speed and exhibit greater gait asymmetry than controls. Gait speed and asymmetry can be readily assessed clinically and represent a simple way of objectively evaluating gait dysfunction and monitoring treatment progress in individuals with hip OA.

Deciphering the role of 75kDa SirT1 fragment in osteoarthritis

s / Osteoarthritis and Cartilage 21 (2013) S9–S62 S49 Fig. Molecular networks generated from the genes differentially expressed by age. The molecular networks generated from genes differentially expressed in meniscus by age (top: up-regulated genes; bottom: down-regulated genes) using GRANITE. The colors are based on the database from which the network is extracted. ellipse 1⁄4 protein; square 1⁄4 transcription factor 79 DECIPHERING THE ROLE OF 75KDA SIRT1 FRAGMENT IN OSTEOARTHRITIS M. Dvir-Ginzberg y, H. Oppenheimer y, H. Meir y, O. Gabay z, K. Zaal z, C. Sanchez x, A. Haze k, L. Kandel k, M. Leibergall k. yHebrew Univ. of Jerusalem, Jerusalem, Israel; zNIAMS, NIH, MD, USA; xHebrew Univ. of Jerusalem, University of Liege, Liege, Belgium; kHebrew Univ. of JerusalemHadassah Med. Center, Jerusalem, Israel Objective: SirT1 is a nuclear NAD-dependent deacetylase associated with cellmetabolismand survival. In joints, recent evidence shows that it regulates cartilage homeostasis and is involved in the inflammatory phase of osteoarthritis (OA). It is widely held that the inflammatory cytokines tumor necrosis factor alpha (TNFa), and interleukin 1b (IL-1b) may elicit chondrocyte death associated with the deterioration of articular cartilage (AC) in OA. Exposing human chondrocytes to both cytokines leads to cathepsin B-mediated cleavage of the nuclear full-length SirT1 (FLSirT1; 110kDa) to generate a stable but enzymatically inactive 75kDa fragment of SirT1 (75SirT1). Here we aim to elucidate the biological andbiochemical role of 75kDa SirT1 fragment in-vivo and in-vitro Methods: Using immunoblot analyses we aimed to detect cathepsin B, FLSirT1 and/or 75SirT1 in OA and normal human chondrocytes. Confocal imaging of SirT1 was used tomonitor its subcellular trafficking following TNFa stimulation of human chondrocytes. Coimmunofluorescent staining for cathepsin B, mitochondrial cytochrome oxidase subunit IV and lysosome-associated membrane protein 1 together with SirT1was performed. Human chondrocytes were tested for apoptosis by fluorescence-activated cell sorter analysis and immunoblotting for caspases 3 and 8. Human chondrocyte mitochondrial extracts were obtained and analyzed for 75SirT1-cytochrome C association. In-vivo assays of heterozygous haploinsufficient (SirT1+/-) and wildtype (WT; SirT1+/+) 129/J mice aged 1 or 9 months were systematically compared for musculoskeletal features, scored for osteoarthritis (OA) severity, and monitored for chondrocyte apoptosis in articular cartilage. Protein extracts from articular chondrocytes were isolated and immunoblotted for SirT1 and active caspase 3. Results: Confocal imaging, immunoprecipitation assays and immunoblot analyses following TNFa challenge of human chondrocytes exhibited that 75SirT1 was generated and exported to the cytoplasm wherein it colocalized with the mitochondrial membrane and associates with cytochrome C. Additionally, levels of cathepsin B and 75SirT1 were elevated in OA versus normal chondrocytes. Subjecting human chondrocytes to TNFa and a cathepsin B inhibitor (ALLN), enhanced levels of apoptotic cell and cleaved caspase 3. Immunoblot assays comparing medial tibial plateau articular cartilage (MTP-AC) of heterozygous haploinsufficient (SirT1+/-) and wild-type (WT; SirT1+/+) 129/J mice revealed reduced levels of FLSirT1 in both strains at 9 months compared to their 1 month equivalent. WT 9-monthold strains presented the 75SirT1 fragments in immunoblot assays, whereas age-matched SirT1+/-mice possessed undetected 75SirT1 levels. Interestingly, 9 month-old SirT1+/mice exhibited increased OA severity andaugmented levels of apoptosis comparedwithage-matchedWTmice. Conclusion: Despite 75SirT1 being enzymatically impaired our results show that it is relatively stable and participates in promoting chondrocyte survival following exposure to proinflammatory cytokines or during articular cartilage maturation. 80 ASYMPTOMATIC INDIVIDUALS WITH RADIOGRAPHIC EVIDENCE OF KNEE OSTEOARTHRITIS WALK WITH DIFFERENT KNEE MECHANICS PATTERNS THAN SYMPTOMATIC INDIVIDUALS WITH THE SAME RADIOGRAPHIC EVIDENCE J.L. Astephen Wilson, G. Hatfield, W.D. Stanish, C.L. HubleyKozey. Dalhousie Univ., Halifax, NS, Canada

Asymptomatic individuals with radiographic evidence of knee osteoarthritis walk with different knee mechanics patterns than symptomatic individuals with the same radiographic evidence

Asymptomatic individuals with radiographic evidence of knee osteoarthritis walk with different knee mechanics patterns than symptomatic individuals with the same radiographic evidence