The Gait Deviation Index Is Associated with Hip Muscle Strength and Patient-Reported Outcome in Patients with Severe Hip Osteoarthritis-A Cross-Sectional Study

Does self-reported physical activity relate to physical function and walking ability in female patients with hip osteoarthritis? A cross-sectional multicenter study

BACKGROUND

The effectiveness of a high level of physical activity in maintaining physical function in patients with hip osteoarthritis has not been adequately examined.

OBJECTIVE

This study aimed to determine whether self-reported physical activity is associated with physical function and walking ability in female patients with hip osteoarthritis.

METHODS

This was a multicenter cross-sectional study. The dependent variables were the lower-limb range of motion and muscle strength, and walking ability. Self-reported physical activity was assessed according to the guidelines of the Japanese Ministry of Health, Labor, and Welfare. Multiple regression models were used to determine whether physical activity was significantly related to the dependent variables after adjusting for confounding factors (age, body mass index, hip pain, comorbidity, and severity of hip osteoarthritis).

RESULTS

A total of 167 participants were included in the study. Physical activity was associated with muscle strength in hip flexion (affected/unaffected, β = 0.18/β = 0.16), abduction (β = 0.19/β = 0.26), knee extension (β = 0.22/β = 0.26), Timed Up-and-Go test (β = -0.16), and 5-m walking time test (β = -0.15).

CONCLUSION

In female patients with hip osteoarthritis, greater physical activity was associated with greater lower extremity muscle strength and walking ability.

Stepping Beyond Counts in Recovery of Total Hip Arthroplasty: A Prospective Study on Passively Collected Gait Metrics

Gait quality parameters have been used to measure recovery from total hip arthroplasty (THA) but are time-intensive and previously could only be performed in a lab. Smartphone sensor data and algorithmic advances presently allow for the passive collection of qualitative gait metrics. The purpose of this prospective study was to observe the recovery of physical function following THA by assessing passively collected pre- and post-operative gait quality metrics. This was a multicenter, prospective cohort study. From six weeks pre-operative through to a minimum 24 weeks post-operative, 612 patients used a digital care management application that collected gait metrics. Average weekly walking speed, step length, timing asymmetry, and double limb support percentage pre- and post-operative values were compared with a paired-sample t-test. Recovery was defined as the post-operative week when the respective gait metric was no longer statistically inferior to the pre-operative value. To control for multiple comparison error, significance was set at p < 0.002. Walking speeds and step length were lowest, and timing asymmetry and double support percentage were greatest at week two post-post-operative (p < 0.001). Walking speed (1.00 ± 0.14 m/s, p = 0.04), step length (0.58 ± 0.06 m/s, p = 0.02), asymmetry (14.5 ± 19.4%, p = 0.046), and double support percentage (31.6 ± 1.5%, p = 0.0089) recovered at 9, 8, 7, and 10 weeks post-operative, respectively. Walking speed, step length, asymmetry, and double support all recovered beyond pre-operative values at 13, 17, 10, and 18 weeks, respectively (p < 0.002). Functional recovery following THA can be measured via passively collected gait quality metrics using a digital care management platform. The data suggest that metrics of gait quality are most negatively affected two weeks post-operative; recovery to pre-operative levels occurs at approximately 10 weeks following primary THA, and follows a slower trajectory compared to previously reported step count recovery trajectories.

Evaluating the contribution of fat infiltration in anterior gluteus minimus muscle to walking ability in female with unilateral hip osteoarthritis and candidates for total hip arthroplasty

BACKGROUND

The purpose of this study is to investigate the relationship between gait and fat infiltration in anterior and posterior gluteus minimus in the patients with hip osteoarthritis.

METHODS

Ninety-one female patients who were diagnosed as the unilateral hip osteoarthritis, classified into Kellgren-Lawrence global scoring system grades 3 or 4, and candidate for total hip arthroplasty were retrospectively reviewed. The horizontally cross-sectional regions of interest for the gluteus medius and anterior and posterior gluteus minimus were manually circumscribed in a single transaxial computed tomography image and muscle density of those regions were obtained. The gait was assessed as the step and speed with the 10-Meter Walk Test. The multiple regression analysis was used to compare the step and speed with age, height, range of motion in flexion, the muscle density of anterior gluteus minimus in the affected side, and that of gluteus medius muscle in both affected and unaffected sides.

FINDINGS

Multiple regression analysis for step revealed that the muscle density of anterior gluteus minimus in the affected side and height were the independent predictors for step (R² = 0.389, p < 0.001). That for speed identified the muscle density of anterior gluteus minimus in the affected side as the only factor determining speed (R² = 0.287, p < 0.001).

INTERPRETATION

The fatty infiltration of anterior gluteus minimus muscle in affected side can be a predictor for the gait in in female with unilateral hip osteoarthritis and candidates for total hip arthroplasty.

Gait function improvements, using Cardiff Classifier, are related to patient-reported function and pain following hip arthroplasty

Summarizing results of three-dimensional (3D) gait analysis into a comprehensive measure of overall gait function is valuable to discern to what extent gait function is affected, and later recovered after surgery and rehabilitation. This study aimed to investigate whether preoperative gait function, quantified and summarized using the Cardiff Classifier, can predict improvements in postoperative patient-reported activities of daily living, and overall gait function 1 year after total hip arthroplasty (THA). Secondly, to explore relationships between pre-to-post surgical change in gait function versus changes in patient-reported and performance-based function. Thirty-two patients scheduled for THA and 25 nonpathological individuals were included in this prospective cohort study. Patients were evaluated before THA and 1 year postoperatively using 3D gait analysis, patient-reported outcomes, and performance-based tests. Kinematic and kinetic gait parameters, derived from 3D gait analysis, were quantified using the Cardiff Classifier. Linear regressions investigated the predictive value of preoperative gait function on postoperative outcomes of function, and univariate correlations explored relationships between pre-to-post surgical changes in outcome measures. Preoperative gait function, by means of Cardiff Classifier, explained 35% and 30% of the total variance in change in patient-reported activities of daily living, and in gait function, respectively. Moderate-to-strong correlations were found between change in gait function and change in patient-reported function and pain, while no correlations were found between change in gait function and performance-based function. Clinical significance: Preoperative gait function predicts postsurgical function to a moderate degree, while improvements in gait function after surgery are more closely related to how patients perceive function than their maximal performance of functional tests.

Application of the Gait Deviation Index to Study Gait Impairment in Adult Population With Spinal Cord Injury: Comparison With the Walking Index for Spinal Cord Injury Levels

The Gait Deviation Index (GDI) is a multivariate measure of overall gait pathology based on 15 gait features derived from three-dimensional (3D) kinematic data. GDI aims at providing a comprehensive, easy to interpret, and clinically meaningful metric of overall gait function. It has been used as an outcome measure to study gait in several conditions: cerebral palsy (CP), post-stroke hemiparetic gait, Duchenne muscular dystrophy, and Parkinson’s disease, among others. Nevertheless, its use in population with Spinal Cord Injury (SCI) has not been studied yet. The aim of the present study was to investigate the applicability of the GDI to SCI through the assessment of the relationship of the GDI with the Walking Index for Spinal Cord Injury (WISCI) II. 3D gait kinematics of 34 patients with incomplete SCI (iSCI) was obtained. Besides, 3D gait kinematics of a sample of 50 healthy volunteers (HV) was also gathered with Codamotion motion capture system. A total of 302 (iSCI) and 446 (HV) strides were collected. GDI was calculated for each stride and grouped for each WISCI II level. HV data were analyzed as an additional set. Normal distribution for each group was assessed with Kolmogorov-Smirnov tests. Afterward, ANOVA tests were performed between each pair of WISCI II levels to identify differences among groups (p < 0.05). The results showed that the GDI was normally distributed across all WISCI II levels in both iSCI and HV groups. Furthermore, our results showed an increasing relationship between the GDI values and WISCI II levels in subjects with iSCI, but only discriminative in WISCI II levels 13, 19, and 20. The index successfully distinguished HV group from all the individuals with iSCI. Findings of this study indicated that the GDI is not an appropriate multivariate walking metric to represent the deviation of gait pattern in adult population with iSCI from a normal gait profile when it is compared with the levels of walking impairment described by the WISCI II. Future work should aim at defining and validating an overall gait index derived from 3D kinematic gait variables appropriate for SCI, additionally taking into account other walking ability outcome measures.

MRI Assessment of Muscle Damage After the Posterolateral Versus Direct Anterior Approach for THA (Polada Trial). A Randomized Controlled Trial

BACKGROUND

There is controversy in literature whether the direct anterior approach (DAA) results in less muscle damage compared with the posterolateral approach (PLA) for total hip arthroplasty. The aim of this randomized controlled trial was to assess muscle damage between these two approaches.

METHODS

Forty-six patients were included. Muscle atrophy, determined with the Goutallier classification, and muscle surface of twelve muscles were analyzed on magnetic resonance imaging images made preoperatively and one year postoperatively. Differences in component placement after DAA or PLA were assessed on radiographs. Harris hip scores and Hip disability and Osteoarthritis and Outcome Score were used as functional outcomes.

RESULTS

External rotator musculature was damaged in both approaches. After PLA, the obturator muscles showed significantly more atrophy and a decrease in muscle surface. After DAA, the tensor fascia latae showed an increased muscle atrophy and the psoas muscle showed a decreased muscle surface. An increase in muscle surface was seen for the rectus femoris, sartorius, and quadratus femoris after both approaches. The muscle surface of the gluteus medius and iliacus was also increased after PLA. No difference in muscle atrophy was found between the approaches for these muscles. The inclination angle of the cup in PLA was significantly higher. No differences were found in functional outcomes.

CONCLUSION

Different muscle groups were affected in the two approaches. After PLA, the external rotators were more affected, whereas the tensor fascia latae and psoas muscles were more affected after DAA.

Assessing Site Specificity of Osteoarthritic Gait Kinematics with Wearable Sensors and Their Association with Patient Reported Outcome Measures (PROMs): Knee versus Hip Osteoarthritis

There is a great need for quantitative outcomes reflecting the functional status in patients with knee or hip osteoarthritis (OA) to advance the development and investigation of interventions for OA. The purpose of this study was to determine if gait kinematics specific to the disease—i.e., knee versus hip OA—can be identified using wearable sensors and statistical parametric mapping (SPM) and whether disease-related gait deviations are associated with patient reported outcome measures. 113 participants (N = 29 unilateral knee OA; N = 30 unilateral hip OA; N = 54 age-matched asymptomatic persons) completed gait analysis with wearable sensors and the Knee/Hip Osteoarthritis Outcome Score (KOOS/HOOS). Data were analyzed using SPM. Knee and hip kinematics differed between patients with knee OA and patients with hip OA (up to 14°, p < 0.001 for knee and 8°, p = 0.003 for hip kinematics), and differences from controls were more pronounced in the affected than unaffected leg of patients. The observed deviations in ankle, knee and hip kinematic trajectories from controls were associated with KOOS/HOOS in both groups. Capturing gait kinematics using wearables has a large potential for application as outcome in clinical trials and for monitoring treatment success in patients with knee or hip OA and in large cohorts representing a major advancement in research on musculoskeletal diseases.

Risk of Falling in a Timed Up and Go Test Using an UWB Radar and an Instrumented Insole

Previously, studies reported that falls analysis is possible in the elderly, when using wearable sensors. However, these devices cannot be worn daily, as they need to be removed and recharged from time-to-time due to their energy consumption, data transfer, attachment to the body, etc. This study proposes to introduce a radar sensor, an unobtrusive technology, for risk of falling analysis and combine its performance with an instrumented insole. We evaluated our methods on datasets acquired during a Timed Up and Go (TUG) test where a stride length (SL) was computed by the insole using three approaches. Only the SL from the third approach was not statistically significant (p = 0.2083 > 0.05) compared to the one provided by the radar, revealing the importance of a sensor location on human body. While reducing the number of force sensors (FSR), the risk scores using an insole containing three FSRs and y-axis of acceleration were not significantly different (p > 0.05) compared to the combination of a single radar and two FSRs. We concluded that contactless TUG testing is feasible, and by supplementing the instrumented insole to the radar, more precise information could be available for the professionals to make accurate decision.

A 12-week exercise program for patients with hip osteoarthritis has no influence on gait parameters: A secondary analysis of a randomized controlled trial

BACKGROUND

Hip osteoarthritis is a major musculoskeletal disorder in the elderly. Evidence is given for the efficacy of exercise interventions in terms of self-reported physical functioning and pain. However, it has not yet been fully examined whether exercises influence gait.

RESEARCH QUESTION

The purpose of this RCT therefore was to evaluate effects of a 12-week exercise program on kinematic gait variables in subjects with hip osteoarthritis.

METHODS

210 participants were randomly assigned to exercise, non-treated control, or placebo ultrasound groups. The 12-week exercise intervention combined a weekly group session with home-based exercises (2/week), which entailed exercises for motor learning, flexibility, strengthening, and balance. Placebo ultrasound was given once a week. A 6-camera motion capture system was used for data collection. Data were derived from shod walking at self-selected speeds. Spatio-temporal and hip and knee joint angles of the stance phase were calculated. Data were averaged across five trials. Measurements were taken prior to and immediately after the intervention period. ANOVA/Kruskall-Wallis-Tests were used to analyze between-group effects for differences between test days. Pairwise comparisons were subsequently conducted in case of significant model effects. Data were analyzed per protocol (n = 185).

RESULTS

No statistically significant differences were detected for any of the outcome measures.

SIGNIFICANCE

Although hip muscle strength and gait quality are related, strength training of the hip-surrounding musculature without specific gait training elements cannot improve spatio-temporal gait characteristics or hip and knee joint angles in subjects with mild to moderate hip osteoarthritis. If gait should explicitly be improved through exercise, interventions must incorporate a relevant portion of gait-related tasks.

Kinematic Gait Analysis After Primary Total Hip Replacement: A Systematic Review: Gait After Total Hip Replacement: A Systematic Review

Total hip replacement (THR) is a surgical procedure indicated for patients affected by severe hip osteoarthritis. Although this technique has proved to be effective in relieving pain and restoring function, gait limitations may persist following this procedure. The objective of this systematic review was to evaluate gait kinematics after THR and compare the results with those of the pre-operative state and with healthy control individuals. PubMed/MEDLINE, Embase, Web of Science, CENTRAL and Scopus databases were searched until December 2019. Methodological quality and internal validity score of each study were assessed using the PEDro and the Newcastle-Ottawa scales. In all, ten studies met our inclusion criteria. Following THR, statistically significant improvements were seen in dynamic hip and knee range of motion of both the affected and the contralateral limb, single-limb support time symmetry, step length, stride length, walking speed and gait pattern. However, deficits were observed in all the previous parameters, as well as in hip adduction angle in comparison with healthy subjects. In conclusion, gait patterns improve after THR in comparison with the pre-operative state, although there are deficits relative to healthy individuals.

Is the Pelvis-Thorax Coordination a Valuable Outcome Instrument to Assess Patients With Hip Osteoarthritis?

Objective: The evaluation of the disease severity in hip osteoarthritis (OA) patients being currently based on subjective instruments. It would be of interest to develop more objective instruments, for example based on gait analysis. The aims of this study were to explore if pelvis-thorax coordination parameters could be valuable instrument outcomes to achieve this evaluation by assessing their reliability, discriminant capacity and responsiveness.

Methods: Three groups of subjects; healthy, hip OA patients with severe disease (defined as indication to surgery), hip OA patients with less severe disease (no indication to surgery) were included. Hip OA patients with severe disease were evaluated before and 6 months after surgery. Subjects had to perform a gait analysis at comfortable speed, and pelvis-thorax coordination was evaluated. The correlations with clinical and structural parameters, as well as reliability, discriminant capacities and responsiveness, were assessed.

Results: The pelvis-thorax coordination in the coronal plane during walking was correlated to clinical and to structural severity in hip OA patients (R² = 0.13). The coronal plane coordination allowed to discriminate healthy subjects from all hip OA patients (sensibility = 0.86; specificity = 0.59). Moreover, when comparing OA patients only, coronal plane coordination allows to discriminate patients with indication of surgery from those with no indication of surgery (sensibility = 0.72; specificity = 0.72). Moreover, the pelvis-thorax coordination demonstrated an excellent reliability and a good responsiveness.

Conclusion: Changes in the pelvis-thorax coordination might refer to different mechanisms, from analgesia to motor control plasticity, and might be a possible explanation for the weak correlation between structure and symptoms in hip OA patients. Moreover, such parameter might be used as an objective outcome in hip OA clinical trials.

Clinical Trials Registration:www.ClinicalTrials.gov, identifier: NCT02042586 and NCT01907503.

Increased Muscle Strength Limits Postural Sway During Daily Living Activities in Total Hip Arthroplasty Patients

Supplemental digital content is available in the text.

Objective

The aim of the study was to investigate the effect of maximal strength training on postural sway after total hip arthroplasty, performed before and after a battery of physical performance tests that resemble daily living activities.

Design

This study is an exploratory study based on data from a 3-mo randomized controlled trial involving 54 total hip arthroplasty patients performing maximal strength training or conventional rehabilitation. At 3, 6, and 12 mos postoperatively, postural sway was evaluated in two gait tests; ie, one test before and one test after conducting a battery of physical performance tests.

Results

At 3 mos postoperatively, postural sway in the test after was significantly higher for the conventional rehabilitation group than the maximal strength training group (P = 0.045); however, there was no between-group difference at the test before (P = 0.670). Postural sway was also significantly higher in the test after compared with the test before in the conventional rehabilitation group (P < 0.001). No difference was found between the test before and test after in the maximal strength training group (P = 0.713). At 6 and 12 mos postoperatively, there were no statistically significant within- or between-group differences in postural sway.

Conclusions

Increased muscular strength limits postural sway 3 mos postoperatively in total hip arthroplasty patients after a demanding battery of physical performance tests simulating daily living activities.

Association between Gait Deviation Index and Physical Function in Children with Bilateral Spastic Cerebral Palsy: A Cross-Sectional Study

This study examined the association between Gait Deviation Index (GDI) and the five-times-sit-to-stand test (FTSST) or gait speed results, which represent mobility and muscle strength of the lower extremities in ambulatory children with Gross Motor Function Classification System (GMFCS) level I and II spastic cerebral palsy. In this cross-sectional, observational study, three-dimensional gait analysis data were obtained during gait trials to evaluate the GDI in 35 children (age 5–16 years) with spastic palsy. Motor function was evaluated using FTSST and gait speed. Gross motor function was evaluated using GMFCS. Children with GMFCS level II spastic cerebral palsy demonstrated lower GDI (p < 0.001) and poorer FTSST (p = 0.031) than those with GMFCS level I spastic cerebral palsy. Correlation analysis showed that FTSST results were significantly correlated with GDI (r = −0.624; p < 0.001). Motor function may be important for the maintenance of gait quality in patients with GMFCS level I and II spastic cerebral palsy and should not be ignored. In conclusion, reduction in gait impairment may affect the values of FTSST and GDI in patients with spastic cerebral palsy who can ambulate without an assistive device.

The Gait Deviation Index as an indicator of gait abnormality among degenerative spinal pathologies

INTRODUCTION

The Gait Deviation Index (GDI) is a composite measure of gait abnormality derived from lower-limb joint range-of-motion which is increasingly being reported for clinical gait analysis among neurologic and orthopedic patients. A GDI score of 100 is representative of healthy individuals and decreasing scores represent a greater abnormality. Preliminary data is needed to help assess the utility of GDI as a measure of compromised gait among spine patients and to provide reference values for commonly treated pathologies.

METHODS

GDI scores were obtained from healthy adults and four symptomatic degeneration groups: cervical spondylotic myelopathy (CSM), adult degenerative scoliosis (ADS), and single-level lumbar degeneration (LD). Clinical gait analysis was done using a three-dimensional motion tracking system. Evaluations were done 1 week prior to surgical intervention for degeneration groups. Two-sample t-tests were used to compare degenerative cohorts to healthy controls and for inter-cohort comparisons. Pearson correlations were used to test for significant relationships between GDI and walking speed.

RESULTS

Degenerative cohorts all showed significantly lower (worse) GDI scores compared to healthy (all p < 0.001). CSM patients showed the best GDI scores with an average of 90, and LD patients showed the worst GDI scores with an average of 86. Worsening GDI significantly correlated with decreased walking speed among ADS patients.

CONCLUSION

Composite metrics like GDI provide a tempting means to summarize nuanced and complex gait characteristics into a single, comparable value among cohorts. The results of this study provide preliminary GDI scores for common degenerative spine pathologies. These slides can be retrieved under Electronic Supplementary Material.

Changes in muscle strength of the hip after rotational acetabular osteotomy: a retrospective study

AIMS

Rotational acetabular osteotomy (RAO) is an effective joint-preserving surgical treatment for acetabular dysplasia. The purpose of this study was to investigate changes in muscle strength, gait speed, and clinical outcome in the operated hip after RAO over a one-year period using a standard protocol for rehabilitation.

PATIENTS AND METHODS

A total of 57 patients underwent RAO for acetabular dysplasia. Changes in muscle strength of the operated hip, 10 m gait speed, Japanese Orthopaedic Association (JOA) hip score, and factors correlated with hip muscle strength after RAO were retrospectively analyzed.

RESULTS

Three months postoperatively, the strength of the operated hip in flexion and abduction and gait speed had decreased from their preoperative levels. After six months, the strength of flexion and abduction had recovered to their preoperative level, as had gait speed. At one-year follow-up, significant improvements were seen in the strength of hip abduction and gait speed, but muscle strength in hip flexion remained at the preoperative level. The mean JOA score for hip function was 91.4 (51 to 100)) at one-year follow-up. Body mass index (BMI) showed a negative correlation with both strength of hip flexion (r = -0.4203) and abduction (r = -0.4589) one year after RAO. Although weak negative correlations were detected between strength of hip flexion one year after surgery and age (r = -0.2755) and centre-edge (CE) angle (r = -0.2989), no correlation was found between the strength of abduction and age and radiological evaluations of CE angle and acetabular roof obliquity (ARO).

CONCLUSION

Hip muscle strength and gait speed had recovered to their preoperative levels six months after RAO. The clinical outcome at one year was excellent, although the strength of hip flexion did not improve to the same degree as that of hip abduction and gait speed. A higher BMI may result in poorer recovery of hip muscle strength after RAO. Radiologically, acetabular coverage did not affect the recovery of hip muscle strength at one year's follow-up. A more intensive rehabilitation programme may improve this. Cite this article: Bone Joint J 2019;101-B:1459-1463.

Does the Femoral Head Size in Hip Arthroplasty Influence Lower Body Movements during Squats, Gait and Stair Walking? A Clinical Pilot Study Based on Wearable Motion Sensors

A hip prosthesis design with larger femoral head size may improve functional outcomes compared to the conventional total hip arthroplasty (THA) design. Our aim was to compare the range of motion (RoM) in lower body joints during squats, gait and stair walking using a wearable movement analysis system based on inertial measurement units (IMUs) in three age-matched male groups: 6 males with a conventional THA (THAC), 9 with a large femoral head (LFH) design, and 8 hip- and knee-asymptomatic controls (CTRL). We hypothesized that the LFH design would allow a greater hip RoM, providing movement patterns more like CTRL, and a larger side difference in hip RoM in THAC when compared to LFH and controls. IMUs were attached to the pelvis, thighs and shanks during five trials of squats, gait, and stair ascending/descending performed at self-selected speed. THAC and LFH participants completed the Hip dysfunction and Osteoarthritis Outcome Score (HOOS). The results showed a larger hip RoM during squats in LFH compared to THAC. Side differences in LFH and THAC groups (operated vs. non-operated side) indicated that movement function was not fully recovered in either group, further corroborated by non-maximal mean HOOS scores (LFH: 83 ± 13, THAC: 84 ± 19 groups, vs. normal function 100). The IMU system may have the potential to enhance clinical movement evaluations as an adjunct to clinical scales.

Individuals with knee osteoarthritis present increased gait pattern deviations as measured by a knee-specific gait deviation index

BACKGROUND

A biomechanical analysis can provide valuable information on osteoarthritis (OA) gait, but important multidimensional interactions are often ignored. The Gait Deviation Index (GDI) was designed to address the issue of data complexity in gait analyses by providing a single, encompassing, value for one's deviation from a normative reference group.

RESEARCH QUESTION

The primary aim of this study was to examine differences in a knee-specific GDI among young adults, and older individuals with and without knee OA. Secondarily, we aimed to examine these differences while controlling for gait speed.

METHOD

Sagittal and frontal plane knee joint angles and moments were used in the computation of a GDI among young adults, and older individuals with and without knee OA. The GDI was calculated such that scores ≥100% were considered typical young-healthy gait and a 10% decrease below 100 equated to 1 standard deviation from typical gait. Scores were first examined using a one-way analysis of variance, and examined again after correcting for gait speed.

RESULTS

The GDI was calculated for three groups: young-healthy adults (n = 52), older individuals without knee OA (n = 56), and individuals with knee OA (n = 191). Those with knee osteoarthritis exhibited a mean GDI of 87.2 (11.1), which was significantly lower than young adults (99.6 (10.6); p < 0.001) and older individuals without knee OA (94.3 (11.0); p < 0.001). Differences in GDI remained consistent after controlling for gait speed. Knee OA gait waveforms displayed significant variability across similar GDIs, specifically in frontal plane patterns.

CONCLUSION

Those with knee osteoarthritis exhibited lower (worse) GDIs compared to those without knee osteoarthritis and young, healthy individuals. After correcting for gait speed, these findings did not change. The GDI highlighted the significant variability in gait waveforms within individuals with knee OA, but the clinical utility of the GDI score itself remains limited.

Gait- and Posture-Related Factors Associated With Changes in Hip Pain and Physical Function in Patients With Secondary Hip Osteoarthritis: A Prospective Cohort Study

OBJECTIVE

To identify gait- and posture-related factors associated with changes in hip pain and physical function in patients with hip osteoarthritis (OA).

DESIGN

Prospective cohort study.

SETTING

Clinical biomechanics laboratory of a university.

PARTICIPANTS

Consecutive sampling of female patients with mild-to-moderate secondary hip OA (N=30).

MAIN OUTCOME MEASURES

Hip pain (visual analog scale) and physical function (physical component summary of the Medical Outcomes Study 36-Item Short-Form Health Survey) were measured at baseline and 12 months later. With changes in hip pain and physical function as dependent variables, linear regression analyses were performed with gait- and posture-related factors as independent variables with and without adjustment for age, joint space width, and hip pain or physical function at baseline. Posture-related factors included angles of thoracic kyphosis, lumbar lordosis, sacral inclination, spinal inclination, and spinal mobility. Gait-related factors were walking speed, steps per day, joint angles, external hip joint moment impulses, and daily cumulative hip moments.

RESULTS

Multiple linear regression analyses showed that limited hip extension (adjusted standardized B coefficient [95% confidence interval]: -0.52 [-0.88 to -0.17]) and limited external rotation angles (-0.51 [-0.85 to -0.18]) during walking were associated with the worsening of hip pain. An increased thoracic kyphosis (-0.54 [-0.99 to -0.09]), less sacral anterior tilt (0.40 [0.01-0.79]), reduced thoracic spine mobility (0.59 [0.23-0.94]), less steps per day (0.53 [0.13-0.92]), and a slower walking speed (0.45 [0.04-0.86]) were associated with deterioration in physical function.

CONCLUSIONS

Gait- and posture-related factors should be considered when assessing risk and designing preventive interventions for the clinical progression of secondary hip OA.

Measurement properties of the OARSI core set of performance-based measures for hip osteoarthritis: a prospective cohort study on reliability, construct validity and responsiveness in 90 hip osteo-arthritis patients

Background and purpose - Improvement of physical function is one of the main treatment goals in severe hip osteoarthritis (OA) patients. The Osteoarthritis Research Society International (OARSI) has identified a core set of performance-based tests to assess the construct physical function: 30-s chair stand test (30-s CST), 4x10-meter fast-paced walk test (40 m FPWT), and a stair-climb test. Despite this recommendation, available evidence on the measurement properties is limited. We evaluated the reliability, validity, and responsiveness of these performance-based measures in patients with hip OA scheduled for total hip arthroplasty (THA). Patients and methods - Baseline and 12-month follow-up measurements were prospectively obtained in 90 end-stage hip OA patients who underwent THA. As there is no gold standard for comparison, the hypothesis testing method was used for construct validity and responsiveness analysis. A test can be assumed valid if ≥75% of predefined hypotheses are confirmed. A subgroup (n = 30) underwent test-retest measurements for reliability analysis. The Oxford Hip Score, Hip injury and Osteoarthritis Outcome Score-Physical Function Short Form, pain during activity score, and muscle strength were used as comparator instruments. Results - Test-retest reliability was appropriate; intraclass correlation coefficient values exceeded 0.70 for all 3 tests. None of the performance-based measures reached 75% hypothesis confirmation for the construct validity or responsiveness analysis. Interpretation - The performance-based tests have good reliability in the assessment of physical function. Construct validity and responsiveness, using patient-reported measures and muscle strength as comparator instruments, could not be confirmed. Therefore, our findings do not justify their use for clinical practice.

Relationships among subjective patient-reported outcome, quality of life, and objective gait characteristics using wearable foot inertial-sensor assessment in foot-ankle patients

BACKGROUND

This study aimed to determine the relationships between subjective validated patient-reported outcomes and health-related quality of life, to objective gait characteristics in patients with foot-ankle conditions. Objective gait characteristics were obtained using a wearable foot inertial-sensor device as well as by assessing the relationships between spatiotemporal or gait parameters by analyzing the inter-metric correlations.

METHODS

Fifty-two patients with foot-ankle conditions (37 women/15 men, aged 21-75 years) were included in this study. Clinical assessments, including evaluations of validated patient-reported outcomes using visual analog scale foot and ankle score, health-related quality of life using validated Short Form-36, and gait characteristics using a wearable foot inertial-sensor device, were performed and recorded for each patient.

RESULTS

A significant negative correlation was observed between the physical component summary (PCS) and maximal cadence (r = - 0.308, P = 0.025). Significant positive correlations were noted between mean walking speed and mean cadence (r = 0.776, P < 0.001) and between maximal walking speed and mean step length (r = 0.498, P < 0.001). Significant negative correlations were found between the mean cadence and mean step length (r = - 0.491, P < 0.001) and between maximal cadence and mean step length (r = - 0.355, P = 0.009).

CONCLUSIONS

Cadence is an important objective spatiotemporal parameter to assess in foot and ankle patients as it relates well to outcome, with a significantly negatively correlation to subjectively reported PCS in health-related quality of life. Based on inter-metric relationships, an increased cadence might be used to maintain walking speed as a compensatory mechanism in patients with foot-ankle conditions.

A randomized controlled trial on maximal strength training in 60 patients undergoing total hip arthroplasty

Background and purpose - Total hip arthroplasty (THA) patients have reduced muscle strength after rehabilitation. In a previous efficacy trial, 4 weeks' early supervised maximal strength training (MST) increased muscle strength in unilateral THA patients <65 years. We have now evaluated muscle strength in an MST and in a conventional physiotherapy (CP) group after rehabilitation in regular clinical practice. Patients and methods - 60 primary THA patients were randomized to MST or CP between August 2015 and February 2016. The MST group trained at 85-90% of their maximal capacity in leg press and abduction of the operated leg (4 × 5 repetitions), 3 times a week at a municipal physiotherapy institute up to 3 months postoperatively. The CP group followed a training program designed by their respective physiotherapist, mainly exercises performed with low or no external loads. Patients were tested pre- 3, 6, and 12 months postoperatively. Primary outcomes were abduction and leg press strength at 3 months. Other parameters evaluated were pain, 6-min walk test, Harris Hip Score (HHS) and Hip disability and Osteoarthritis Outcome Score (HOOS) Physical Function Short-form score. Results - 27 patients in each group completed the intervention. MST patients were substantially stronger in leg press and abduction than CP patients 3 (43 kg and 3 kg respectively) and 6 months (30 kg and 3 kg respectively) postoperatively (p ≤ 0.002). 1 year postoperatively, no intergroup differences were found. No other statistically significant intergroup differences were found. Interpretation - MST increases muscle strength more than CP in THA patients up to 6 months postoperatively, after 3 months' rehabilitation in clinical practice. It was well tolerated by the THA patients and seems feasible to conduct within regular clinical practice.

The impact of symptomatic knee osteoarthritis on overall gait pattern deviations and its association with performance-based measures and patient-reported outcomes

BACKGROUND

Limited knowledge exists regarding the impact of symptomatic knee osteoarthritis (OA) on the overall gait pattern; and whether gait deviations are associated with performance-based measures (PBMs) and patient-reported outcomes (PROs). This cross-sectional study evaluated overall gait patterns in patients with knee OA using the Gait Deviation Index for kinematics (GDI) and kinetics (GDI-kinetic), and explored associations between gait deviations, PBMs, and PROs.

METHODS

Forty patients with knee OA and 25 age and gender-matched controls underwent three-dimensional gait analysis. Participants performed the Timed Up and Go (TUG), Five Times Sit-to-Stand (5STS), and Single Limb Mini Squat (SLMS) tests and completed a disease-specific PRO. Associations between gait deviations, PBMs, and PROs were assessed by Pearson's correlation and multiple linear regression.

RESULTS

Patients with OA demonstrated significantly lower GDI and GDI-kinetic scores of the OA and contralateral limbs compared to controls; with GDI-kinetic scores on the contralateral limb more impacted than the OA limb. On the contralateral limb, GDI-kinetic score significantly correlated with TUG (r=-0.42) and 5STS (r=-0.33), while on the OA limb with TUG (r=-0.68), 5STS (r=-0.38), SLMS (r=-0.38), activities of daily living (r=0.35) and Knee-related Quality of Life (r=0.35). No significant associations existed between kinematic GDI scores, PBMs and PROs.

CONCLUSION

The overall gait pattern, as represented by GDI and GDI-kinetic scores, in patients with symptomatic knee OA is affected both on the painful OA limb and the contralateral limb. The GDI and GDI-kinetic scores provide different information regarding function that is not revealed by PBMs or PROs.