Association of physical performance with muscle strength and hip range of motion in hip osteoarthritis

Efficacy of proprioceptive neuromuscular facilitation on functioning in patients with bilateral hip osteoarthritis: A pilot randomized controlled trial

BACKGROUND

Hip osteoarthritis (OA) is a chronic progressive disease that impresses a noticeable burden to society and healthcare systems. Physical exercise constitutes the first-line hip OA treatment approach, nevertheless, there is currently no gold standard method to treat this disease.

OBJECTIVE

To evaluate the efficacy of proprioceptive neuromuscular facilitation (PNF) on functioning in patients with hip OA.

METHOD

A pilot randomized controlled trial (RCT) was carried out on patients with painful bilateral hip OA with a body mass index (BMI) < 30 kg/m2. After the randomization, the experimental group was treated with PNF protocol and the control group with conventional physical therapy (10 sessions of manual therapy, 5 sessions/week for 2 weeks). The Harris Hip Score (HHS) was the primary outcome, whereas we assessed as secondary outcomes: pain, range of motion, and muscle strength of hip, physical performance, and quality of life.

RESULTS

Twenty patients (40 hips) were enrolled and randomized into two groups: PNF group (mean age: 70.7 ± 8.07; BMI: 25.1 ± 3.07; 7 females and 3 males) and control group (mean age: 74.9 ± 10.72; BMI: 26.8 ± 3.78; 6 females and 4 males). The results showed a statistically significant improvement of HHS in the study group (T1: 90.6 ± 5.63) than in the control group (T1: 77.3 ± 10.9) (between-group p value < 0.001). Three months after the treatment we have statistically significant maintenance in the PNF group (T2:89.6±6.32, within-group ΔT0-T2 p< 0.01) while the control group did not maintain the improvements recorded at T1 (T2: 71.4 ± 15.8).

CONCLUSION

The results of this pilot RCT showed that incorporating PNF exercises into the rehabilitation program yielded notable enhancements in improving lower limb function, strength and ROM in hip OA patients. Nonetheless, further prospective studies including wider sample size are needed to implement scientific knowledge on this physical therapy approach, in patients with hip osteoarthritis.

Effects of adding aerobic physical activity to strengthening exercise on hip osteoarthritis symptoms: protocol for the PHOENIX randomised controlled trial

BACKGROUND

Hip osteoarthritis (OA) is a leading cause of musculoskeletal pain. Exercise is a core recommended treatment. Most evidence is based on muscle-strengthening exercise, but aerobic physical activity has potential to enhance clinical benefits. The primary aim of this study is to test the hypothesis that adding aerobic physical activity to a muscle strengthening exercise leads to significantly greater reduction in hip pain and improvements in physical function, compared to a lower-limb muscle strengthening exercise program alone at 3 months.

METHODS

This is a superiority, 2-group, parallel randomised controlled trial including 196 people with symptomatic hip OA from the community. Following baseline assessment, participants are randomly allocated to receive either i) aerobic physical activity and muscle strengthening exercise or; ii) muscle strengthening exercise only. Participants in both groups receive 9 consultations with a physiotherapist over 3 months. Both groups receive a progressive muscle strengthening exercise program in addition to advice about OA management. The aerobic physical activity plan includes a prescription of moderate intensity aerobic physical activity with a goal of attaining 150 min per week. Primary outcomes are self-reported hip pain assessed on an 11-point numeric rating scale (0 = 'no pain' and 10 = 'worst pain possible') and self-reported physical function (Western Ontario and McMaster Universities Osteoarthritis Index physical function subscale) at 3 months. Secondary outcomes include other measures of self-reported pain (assessed at 0, 3, 9 months), self-reported physical function (assessed at 0, 3, 9 months), performance-based physical function (assessed at 0, 3 months), joint stiffness (assessed at 0, 3, 9 months), quality of life (assessed at 0, 3, 9 months), muscle strength (assessed at 0, 3 months), and cardiorespiratory fitness (assessed at 0, 3 months). Other measures include adverse events, co-interventions, and adherence. Measures of body composition, serum inflammatory biomarkers, quantitative sensory measures, anxiety, depression, fear of movement and self-efficacy are included to explore causal mechanisms.

DISCUSSION

Findings will assist to provide an evidence-based recommendation regarding the additional effect of aerobic physical activity to lower-limb muscle strengthening on hip OA pain and physical function.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry reference: ACTRN 12619001297112. Registered 20th September 2019.

Walking energetics and abductor strength are associated with physical activity in older women with hip osteoarthritis

BACKGROUND

Osteoarthritis (OA) can hinder physical activity in older adults for reasons that are not fully understood. Functional barriers may exist such as reduced muscle strength around the affected joint, potentially affecting physical activity. Aging-associated declines in energy capacity may also be exacerbated by OA. These factors may work together to influence physical activity in people with OA.

RESEARCH QUESTION

Our objective was to evaluate the combined role of walking energetics and hip abductor strength on physical activity in older women with hip OA.

METHODS

We evaluated 30 women with moderately symptomatic hip OA (61 ± 10 yrs; 30.7 ± 4.9 kg/m²) in this cross-sectional observational study. We measured physical activity using the UCLA activity score and quantified activity frequency and intensity using accelerometers worn for seven days (7 ± 2 days). We used a portable oxygen exchange system to measure energy used during walking at preferred speeds (relative to total energy capacity assessed using a six-minute walk test) and a dynamometer to measure hip abductor strength. We used Pearson correlations and regression analysis to test our hypotheses.

RESULTS

Greater energy used during walking was associated with lower self-reported physical activity (R=-0.626, p < 0.001), more sedentary time (R = 0.567, p = 0.002), and less light activity time (R=-0.644, p < 0.001). Lower hip abductor strength was associated with lower self-reported physical activity (R = 0.406, p = 0.039). While there was no association between hip abductor strength and energy used during walking, together these variables predicted 55.5 % of the variance in self-reported physical activity.

SIGNIFICANCE

Results suggest intervention targets to promote physical activity in this population.

Hip joint kinematics and segment coordination variability according to pain and structural disease severity in hip osteoarthritis

This study aimed to evaluate hip joint kinematic variability and segment coordination variability during walking according to pain and radiographic disease severity in people with hip osteoarthritis. Fifty-five participants with hip osteoarthritis had pain severity assessed during walking using an item on the Western Ontario and McMasters Universities Osteoarthritis Index (no pain = 10; mild pain = 28; moderate pain = 17). Radiographic disease severity was graded by Kellgren and Lawrence scale (KL2 = 29; KL3 = 21; KL4 = 5). Hip kinematics variability was estimated as the curve coefficient of variation. Vector coding was used to calculate coordination variability for select joint couplings. One-way analysis of variances with planned adjusted post hoc comparisons were used to compare hip kinematics variability and coordination variability of select segment couplings (pelvis sagittal vs thigh sagittal; pelvis frontal vs thigh frontal; pelvis transverse vs thigh transverse; thigh sagittal vs shank sagittal; thigh frontal vs shank sagittal; thigh transverse vs shank sagittal) according to pain and radiographic disease severity. No main effect of pain severity was observed for sagittal or transverse plane hip kinematic variability (P ≥ .266), and although there was a main effect for frontal plane hip kinematic variability (P = .035), there were no significant differences when comparing between levels of pain severity (P > .006). There was no main effect of radiographic disease severity on hip kinematic variability in the sagittal (P = .539) or frontal (P = .307) plane. No significant differences in coordination of variability of segment couplings were observed (all P ≥ .229). Movement variability as assessed in this study did not differ according to pain severity during walking or radiographic disease severity.

Can effusion-synovitis measured on ultrasound or MRI predict response to intra-articular steroid injection in hip osteoarthritis?

OBJECTIVES

Intra-articular steroid injection (IASI) is an effective therapy for hip osteoarthritis (OA), but carries risks and provides significant pain relief to only two thirds of patients. We attempted to predict response to IASI in hip OA patients using baseline clinical, ultrasound, and MRI data.

METHODS

Observational study of 97 subjects with symptomatic hip OA presenting for IASI. At baseline and 8 weeks we obtained hip MRI, grayscale and Doppler ultrasound, clinical range of motion (ROM), timed-up and go test (TUG) scores, and self-reported Western Ontario and McMaster Universities Osteoarthritis (WOMAC) pain, stiffness, and function scores. Bone-capsule distance (BCD) measurements of inflammation on hip ultrasound and MRI were measured at three locations: the proximal-most uncovered portion of the femoral head, the superficial-most (apex) portion of the femoral head, and the largest fluid pocket at the femoral neck.

RESULTS

Ultrasound and MRI BCD correlated with each other significantly and strongly at the apex and neck. Power Doppler findings did not correlate significantly with any other imaging indices. Eight weeks post-injection, WOMAC pain, function, and stiffness scores significantly improved and TUG time improved nearly to the level of significance, but there were no significant changes in ultrasound, MRI, or Doppler indices. Baseline variables were not significantly different between responder and nonresponder WOMAC pain or TUG time cohorts.

CONCLUSION

Basic measures of inflammation on ultrasound and MRI are highly related to each other, but provide little insight into patient function and pain after IASI. Other mechanisms to explain improvement in patient status after IASI are likely at work.

Sex-specific walking kinematics and kinetics in individuals with unilateral, symptomatic hip osteoarthritis: A cross sectional study

BACKGROUND

Hip osteoarthritis (OA) is a significant cause of disability, with hip pain and reduced external hip moments during walking being key features of the condition. The external hip adduction moment is greater in healthy women than men, however these between-sex differences are not evident in those with end-stage hip OA. Whether sex-specific hip kinetics are associated with early-midstage hip OA has not been investigated and may be a potential target for directed treatment.

METHODS

Thirty-eight women and twenty-eight men with a diagnosis of symptomatic, unilateral, mild-to-moderate hip OA (Kellegren-Lawrence Grade 2 or 3) underwent three-dimensional gait analysis of normal walking gait using Vicon motion capture. Hip joint, trunk and pelvic angles and hip moments were calculated using the Plug-in-Gait model. The external peak flexion moment, and the first peak, second peak and mid-stance minimum of the hip adduction moment during the stance phase of walking as well as hip, trunk and pelvic kinematics occurring at the three moment time points were compared between groups using an analysis of covariance.

RESULTS

Women with hip OA exhibited a greater external hip adduction moment (mean difference 0.8-1.3 N m/BW.Ht(%), P < 0.05) and greater hip adduction angles (mean difference 2.8-4.9 degrees, P < 0.05) throughout stance than men. Men walked with a greater forward trunk lean than women during early to midstance (mean difference 2.9-3.5 degrees, P < 0.05) than women.

SIGNIFICANCE

In contrastto late stage hip OA, between-sex difference in hip joint kinematics and kinetics are preserved in early-midstage hip OA.

Frontal plane hip joint loading according to pain severity in people with hip osteoarthritis

The primary objective was to examine the hip adduction moment during walking in people with hip osteoarthritis (OA) according to pain severity. Sixty-eight participants with unilateral symptomatic hip OA were included. Pain during walking was assessed on a 5-point Likert item within the Western Ontario and McMaster Universities Index (no pain = 12; mild pain n = 37; moderate pain n = 19). Measures of the external hip adduction moment (peaks, Nm/BW × BH (%) and impulse, Nm.s/BW × BH (%)) were determined. Other measures included frontal plane hip, pelvis and trunk kinematics, walking speed and peak isometric hip abductor strength. Variables were compared according to pain severity using linear models and biomechanical variables were examined. Participants with moderate pain had a significantly higher second peak hip adduction moment and impulse compared to those with less pain. There was no difference in any measure of hip adduction moment between those with mild pain and no pain. There were no differences in kinematics across pain severity categories. Participants with moderate pain had a significantly slower walking speed compared to participants with mild and no pain. Participants with moderate pain had weaker peak isometric hip abductor strength compared to those with mild pain and no pain. The hip adduction moment during walking, hip abduction strength and walking speed differs according to pain severity during walking in people with hip OA. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1637-1644, 2018.

Radiographic and clinical factors associated with one-leg standing and gait in patients with mild-to-moderate secondary hip osteoarthritis

A decline in physical function associated with secondary hip osteoarthritis (OA) may be caused by both radiographic and clinical factors; however, the underlying mechanism remains unclear. The purpose of this study was to determine how joint degeneration, hip morphology, pain, hip range of motion (ROM), and hip muscle strength relate to one-leg standing (OLS) and gait in patients with mild-to-moderate secondary hip osteoarthritis. Fifty-five female patients (ages 22-65 years) with mild-to-moderate hip OA secondary to hip dysplasia were consecutively enrolled. Balance during OLS and three-dimensional hip angle changes while maintaining the OLS and at foot-off of the raised leg were measured. Gait speed and peak three-dimensional hip joint angles during gait were also measured. The associations between dependent variables (balance, gait speed, and hip kinematic changes) and independent variables (age, body mass index, pain, joint degeneration, hip morphologic abnormality, passive hip ROM, and hip muscle strength) were determined. While lower hip muscle strength was associated with hip kinematic changes such as flexion and internal rotation while maintaining OLS, decreased acetabular head index (AHI) and increased pain were associated with hip extension and abduction at foot-off in OLS. Decreased passive hip ROM was associated with decreased peak hip angles (extension, adduction, and external and internal rotation) during gait, although increased pain and decreased hip extension muscle strength were associated with slower gait speed. In this study of patients with secondary hip OA, AHI, pain, and hip impairments were associated with OLS and gait independently from age and radiographic degeneration.

Cross-sectional association between muscle strength and self-reported physical function in 195 hip osteoarthritis patients

INTRODUCTION

This study aimed to evaluate associations between strength of selected hip and knee muscles and self-reported physical function, and their clinical relevance, in men and women with hip osteoarthritis (OA).

METHODS

Cross-sectional data from 195 participants with symptomatic hip OA were used. Peak isometric torque of hip extensors, flexors, and abductors, and knee extensors were measured, along with physical function using the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire. Separate linear regressions in men and women were used to determine the association between strength and physical function accounting for age, pain, and radiographic disease severity. Subsequently, magnitudes of strength associated with estimates of minimal clinically important improvement (MCII) in physical function were estimated according to severity of difficulty with physical function.

RESULTS

For men, greater strength of the hip extensors, hip flexors and knee extensors were each associated with better physical function. For women, greater muscle strength of all tested muscles were each associated with better physical function. For men and women, increases in muscle strength between 17-32%, 133-223%, and 151-284% may be associated with estimates of MCII in physical function for those with mild, moderate, and severe physical dysfunction, respectively.

CONCLUSION

Greater isometric strength of specific hip and thigh muscle groups may be associated with better self-reported physical function in men and women. In people with mild physical dysfunction, an estimate of MCII in physical function may be associated with attainable increases in strength. However, in patients with more severe dysfunction, greater and perhaps unattainable strength increases may be associated with an estimate of MCII in physical function. Longitudinal studies are required to validate these observations.

Dynamic hip kinematics in patients with hip osteoarthritis during weight-bearing activities

BACKGROUND

There is an interest in quantifying the hip kinematics of patients with end-stage hip disorders before total hip arthroplasty. The purpose of the present study was to obtain dynamic hip kinematics under four different conditions, including deep flexion and rotation, in patients with osteoarthritis of the hip.

METHODS

Continuous X-ray images were obtained in 14 patients during gait, chair-rising, squatting, and twisting, using a flat panel X-ray detector. These patients received computed tomography scan to generate virtual digitally reconstructed radiographs. The density-based digitally reconstructed radiographs were then compared with the serial X-ray images acquired using image correlations. These 3D-to-2D model-to-image registration techniques determined the 3D positions and orientations of the pelvis and femur during the movement cycle of each activity.

FINDINGS

For gait, chair-rising, and squatting, the maximum hip flexion angles averaged 22°, 64°, and 68°, respectively. The pelvis was tilted anteriorly by an average of around 7° during the full gait cycle. For chair-rising and squatting, the maximum absolute values of anterior/posterior pelvic tilt averaged 8°/17° and 6°/18°, respectively. Hip flexion showed maximum flexion angle on the way of movement due to further anterior pelvic tilt during both chair-rising and squatting. For twisting, the maximum absolute values of internal/external hip rotation averaged 3°/13°.

INTERPRETATION

Patients with hip osteoarthritis prior to total hip arthroplasty demonstrated the limited ranges of coordinated motion of the pelvis, femur, and hip joint during each activity, especially in deeply flexed and rotated postures.

Serum 25-Hydroxyvitamin D and Osteoarthritis in Older People: The Progetto Veneto Anziani Study

Recent work has shown that low 25-hydroxyvitamin D (25OHD) levels are associated with the presence of osteoarthritis (OA), but these studies focused on radiographical changes of OA, investigated only one joint, and did not consider the association with OA-related pain. In this study, we aimed to examine the relationship between 25OHD levels and any presence of OA and pain in a cohort of older people. This study was part of the Progetto Veneto Anziani (Pro.V.A), a population-based cohort study in older people. In this cross-sectional work, we considered 2756 subjects (1102 males and 1654 females) with a mean age of 74.2 ± 7.1 years. OA and OA-related pain were defined using a standardized algorithm investigating disease history, medical documentation, symptoms, and physical examination of the joints. On logistic regression analysis, taking those in the highest 25OHD quartile for reference, those in the lowest quartile had significantly higher odds of OA involving the hands (odds ratio [OR] = 1.26, 95% confidence interval [CI] 1.15-1.38 in the sample as whole; 1.36, 95% CI 1.15-1.60 in men and 1.22, 95% CI 1.09-1.37 in women), and pain (OR = 1.18, 95% CI 1.06-1.32 in the sample as whole; 1.52, 95% CI 1.21-1.90 in men and 1.15, 95% CI 1.03-1.29 in women). Similar results were found for the hip. For the knee, low 25OHD levels were associated with the presence of OA in the sample as a whole, and in women, and with the presence of pain in the sample as a whole. In conclusion, low 25OHD levels are associated with the presence of OA and with OA-related pain, particularly when the hand and hip are involved.

Stiffness, pain, and hip muscle strength are factors associated with self-reported physical disability in hip osteoarthritis

BACKGROUND

Physical disability (PD) is common among patients with osteoarthritis (OA) of the hip. Exercise therapy is proposed to be a potential intervention to reduce PD. However, the optimal targets of an exercise program are not known.

PURPOSE

The aim of the present study was to identify factors that explain the level of self-reported PD in patients with hip OA. Knowledge of these factors will help develop specific and effective exercise programs.

METHODS

Data from 149 patients with hip OA (85 men and 64 women) were analyzed. Self-reported PD was quantified using the physical function subscale of the Western Ontario and McMaster index. A stepwise regression analysis was conducted to identify significant factors associated with self-reported PD.

RESULTS

Stiffness, pain, and hip muscle strength were found to be significant factors related to the level of self-reported PD in hip OA. These factors explained 59% (r adjusted = 0.59) of the variance. Body mass index, gender, age, and passive internal hip rotation and flexion range of motion explained only minor parts of the dependent variable self-reported PD.

DISCUSSION AND CONCLUSION

Stiffness, pain, and hip muscle strength are associated with self-reported PD in hip OA. It is imperative that exercise treatments for hip OA include strategies to modify these factors. Further research should evaluate their role in preventing hip OA.

Effect of early supervised progressive resistance training compared to unsupervised home-based exercise after fast-track total hip replacement applied to patients with preoperative functional limitations. A single-blinded randomised controlled trial

OBJECTIVE

To examine if 2 weekly sessions of supervised progressive resistance training (PRT) in combination with 5 weekly sessions of unsupervised home-based exercise is more effective than 7 weekly sessions of unsupervised home-based exercise in improving leg-extension power of the operated leg 10 weeks after total hip replacement (THR) in patients with lower pre-operative function.

METHOD

A total of 73 patients scheduled for THR were randomised (1:1) to intervention group (IG, home based exercise 5 days/week and PRT 2 days/week) or control group (CG, home based exercise 7 days/week). The primary endpoint was change in leg extension power at 10 week follow up. Secondary outcomes were isometric hip muscle strength, sit-to-stand test, stair climb test, 20 m walking speed and patient-reported outcome (HOOS).

RESULTS

Sixty-two completed the trial (85%). Leg extension power increased from baseline to the 10 week follow up in both groups; mean [95% CI] IG: 0.29 [0.13; 0.45] and CG: 0.26 [0.10; 0.42] W/kg, with no between-group difference (primary outcome) (P = 0.79). Maximal walking speed (P = 0.008) and stair climb performance (P = 0.04) improved more in the IG compared to CG, no other between-group differences existed.

CONCLUSIONS

In this trial, supervised PRT twice a week in addition to 5 weekly sessions of unsupervised exercise for 10 weeks was not superior to 7 weekly sessions of unsupervised home-based exercise for 10 weeks in improving the primary outcome, leg-extension power of the operated leg, at the primary endpoint 10 weeks after surgery in THR patients with lower pre-operative function.

TRIAL REGISTRATION

NCT01214954.

Relationships between physical performance and knee and hip osteoarthritis: findings from the European Project on Osteoarthritis (EPOSA)

BACKGROUND

poor physical performance (PP) is known to be associated with disability, lower quality of life and higher mortality rates. Knee and hip osteoarthritis (OA) might be expected to contribute to poor PP, through joint pain and restricted range of movement. Both clinical and self-reported OA are often used for large-scale community and epidemiological studies.

OBJECTIVE

to examine the relationships between hip and knee OA and PP in a large data set comprising cohorts from six European countries.

METHODS

a total of 2,942 men and women aged 65-85 years from the Germany, Italy, Netherlands, Spain, Sweden and the UK were recruited. Assessment included an interview and clinical assessment for OA. PP was determined from walking speed, chair rises and balance (range 0-12); low PP was defined as a score of ≤9.

RESULTS

the mean (SD) age was 74.2 (5.1) years. Rates of self-reported OA were much higher than clinical OA. Advanced age, female gender, lower educational attainment, abstinence from alcohol and higher body mass index were independently associated with low PP. Clinical knee OA, hip OA or both were associated with a higher risk of low PP; OR (95% CI) 2.93 (2.36, 3.64), 3.79 (2.49, 5.76) and 7.22 (3.63, 14.38), respectively, with relationships robust to adjustment for the confounders above as well as pain.

CONCLUSION

lower limb OA at the hip and knee is associated with low PP, and for clinical diagnosis relationships are robust to adjustment for pain. Those at highest risk have clinical OA at both sites.

A study of the inter-rater reliability of a test battery for use in patients after total hip replacement

Objective:

To assess the within-day inter-rater reliability of a test battery of functional performance, muscle strength and leg extension power on total hip replacement patients.

Design:

A test–retest design was used.

Setting:

Orthopaedic department at a Regional Hospital in Denmark.

Subjects:

Two convenience samples of 20 total hip replacement patients were included.

Intervention:

The tests were performed three months after total hip replacement. Two raters performed test and re-test, with two hours rest in-between.

Main measures:

The test battery included: sit-to-stand performance, 20-metre maximum walking speed, stair climb performance, isometric muscle strength (hip abduction/flexion), and leg extension power. Absolute reliability was assessed with Bland Altman plots, standard error of measurement (SEM), and minimal detectable change. Relative reliability was assessed with intra-class correlation coefficient.

Results:

Systematic differences between testers were seen in tests of walking speed (0.32 seconds p = 0.03) and stair climb performance (0.18 seconds p = 0.003). In per cent of the grand mean, the standard error of measurement was 3%–10%, indicating the measurement error on a group level, and the minimal detectable change was 10%–27%, indicating the measurement error on an individual level. The intra-class correlation coefficients were above 0.80 in all tests (range 0.83–0.95).

Conclusions:

The tests showed acceptable relative and absolute inter-rater reliability on a group level, but not on an individual level (except from test of walking speed and stair climb performance). Systematic differences between testers were considered clinically irrelevant (0.3 and 0.2 seconds).

The avoidance model in knee and hip osteoarthritis: a systematic review of the evidence

The avoidance model in patients with knee and hip osteoarthritis (OA) hypothesizes that pain and psychological distress lead to avoidance of activities, and thereby to muscle weakness and activity limitations. This paper systematically reviews the scientific evidence for the validity of this avoidance model. A qualitative data synthesis was used to identify levels of evidence. Sixty studies were included. In knee OA, strong evidence was found that avoidance of activities is associated with activity limitations via muscle weakness (mediation by muscle weakness), strong evidence was found for an association between muscle weakness and activity limitations, and weak evidence was found that pain and psychological distress are associated with muscle weakness via avoidance of activities (mediation by avoidance). In hip OA, weak evidence was found for mediation by muscle weakness; and strong evidence was found for an association between muscle weakness and activity limitations. More research is needed on the consecutive associations between pain or psychological distress, avoidance of activities and muscle weakness, and to confirm causal relationships.

Associations of self-report physical function with knee strength and knee range-of-motion in total knee arthroplasty possible nonlinear and threshold effects

This study aims to examine, in patients before and following a total knee arthroplasty (TKA), whether knee extensor strength and knee flexion/extension range-of-motion (ROM) were nonlinearly associated with physical function. Data from 501 patients with TKA were analyzed. Knee extensor strength was assessed preoperatively and 6 months postoperatively. Knee ROM and Short Form-36 (SF-36) physical function data were collected from each patient preoperatively, and at 6 and 24 months postoperatively. Knee strength was measured by handheld dynamometry and knee ROM by goniometry. Restricted cubic spline regression was used to examine possible nonlinear associations. At all assessment points, the associations between knee measures and function were not always linear. Some of the associations revealed distinct threshold points. These findings have potential clinical and research implications.

Sagittal plane gait characteristics in hip osteoarthritis patients with mild to moderate symptoms compared to healthy controls: a cross-sectional study

BACKGROUND

Existent biomechanical studies on hip osteoarthritic gait have primarily focused on the end stage of disease. Consequently, there is no clear consensus on which specific gait parameters are of most relevance for hip osteoarthritis patients with mild to moderate symptoms. The purpose of this study was to explore sagittal plane gait characteristics during the stance phase of gait in hip osteoarthritis patients not eligible for hip replacement surgery. First, compared to healthy controls, and second, when categorized into two subgroups of radiographic severity defined from a minimal joint space of ≤/>2 mm.

METHODS

Sagittal plane kinematics and kinetics of the hip, knee and ankle joint were calculated for total joint excursion throughout the stance phase, as well as from the specific events initial contact, midstance, peak hip extension and toe-off following 3D gait analysis. In addition, the Western Ontario and McMaster Universities Osteoarthritis Index, passive hip range of motion, and isokinetic muscle strength of hip and knee flexion and extension were included as secondary outcomes. Data were checked for normality and differences evaluated with the independent Student's t-test, Welch's t-test and the independent Mann-Whitney U-test. A binary logistic regression model was used in order to control for velocity in key variables.

RESULTS

Fourty-eight hip osteoarthritis patients and 22 controls were included in the final material. The patients walked significantly slower than the controls (p=0.002), revealed significantly reduced joint excursions of the hip (p<0.001) and knee (p=0.011), and a reduced hip flexion moment at midstance and peak hip extension (p<0.001). Differences were primarily manifested during the latter 50% of stance, and were persistent when controlling for velocity. Subgroup analyses of patients with minimal joint space ≤/>2 mm suggested that the observed deviations were more pronounced in patients with greater radiographic severity. The biomechanical differences were, however, not reflected in self-reported symptoms or function.

CONCLUSIONS

Reduced gait velocity, reduced sagittal plane joint excursion, and a reduced hip flexion moment in the late stance phase of gait were found to be evident already in hip osteoarthritis patients with mild to moderate symptoms, not eligible for total hip replacement. Consequently, these variables should be considered as key features in studies regarding hip osteoarthritic gait at all stages of disease. Subgroup analyses of patients with different levels of radiographic OA further generated the hypothesis that the observed characteristics were more pronounced in patients with a minimal joint space ≤2 mm.

Reproducibility of range of motion and muscle strength measurements in patients with hip osteoarthritis - an inter-rater study

Background

Assessment of range of motion (ROM) and muscle strength is fundamental in the clinical diagnosis of hip osteoarthritis (OA) but reproducibility of these measurements has mostly involved clinicians from secondary care and has rarely reported agreement parameters. Therefore, the primary objective of the study was to determine the inter-rater reproducibility of ROM and muscle strength measurements. Furthermore, the reliability of the overall assessment of clinical hip OA was evaluated. Reporting is in accordance with proposed guidelines for the reporting of reliability and agreement studies (GRRAS).

Methods

In a university hospital, four blinded raters independently examined patients with unilateral hip OA; two hospital orthopaedists independently examined 48 (24 men) patients and two primary care chiropractors examined 61 patients (29 men). ROM was measured in degrees (deg.) with a standard two-arm goniometer and muscle strength in Newton (N) using a hand-held dynamometer. Reproducibility is reported as agreement and reliability between paired raters of the same profession. Agreement is reported as limits of agreement (LoA) and reliability is reported with intraclass correlation coefficients (ICC). Reliability of the overall assessment of clinical OA is reported as weighted kappa.

Results

Between orthopaedists, agreement for ROM ranged from LoA [-28–12 deg.] for internal rotation to [-8–13 deg.] for extension. ICC ranged between 0.53 and 0.73, highest for flexion. For muscle strength between orthopaedists, LoA ranged from [-65–47N] for external rotation to [-10 –59N] for flexion. ICC ranged between 0.52 and 0.85, highest for abduction. Between chiropractors, agreement for ROM ranged from LoA [-25–30 deg.] for internal rotation to [-13–21 deg.] for flexion. ICC ranged between 0.14 and 0.79, highest for flexion. For muscle strength between chiropractors, LoA ranged between [-80–20N] for external rotation to [-146–55N] for abduction. ICC ranged between 0.38 and 0.81, highest for flexion. Weighted kappa for the overall assessment of clinical hip OA was 0.52 between orthopaedists and 0.65 between chiropractors.

Conclusions

Reproducibility of goniometric and dynamometric measurements of ROM and muscle strength in patients with hip OA is poor between experienced orthopaedists and between experienced chiropractors. Orthopaedists and chiropractors can to a moderate degree differentiate between hips with or without osteoarthritis.

Muscle mass and composition of the hip, thigh and abdominal muscles in women with and without hip osteoarthritis

The objective of this study was to compare muscle mass and composition between individuals with and without hip osteoarthritis. Twenty-four women with hip osteoarthritis (OA group) and 16 healthy women (healthy group) participated in this study. Muscle thickness (MT) and echo intensity (EI) were measured as indices of muscle mass and composition, respectively, using ultrasound imaging. Seven muscles were examined: gluteus maximus, gluteus medius, quadriceps femoris, rectus abdominis, external oblique, internal oblique and transversus abdominis. MT of only quadriceps femoris in the OA group was significantly thinner than that in the healthy group. EIs of gluteus medius, quadriceps femoris and rectus abdominis were significantly higher in the OA group than those in the healthy group. Thus, actual contractile tissue of gluteus medius and rectus abdominis substantially decreased, although muscle mass was similar, whereas both quantitative and qualitative changes occurred in quadriceps femoris in patients with hip OA.

Building the rationale and structure for a complex physical therapy intervention within the context of a clinical trial: a multimodal individualized treatment for patients with hip osteoarthritis

Evaluating the efficacy of complex interventions such as multimodal, impairment-based physical therapy treatments in randomized controlled trials is essential to inform practice and compare relative benefits of available treatment options. Studies of physical therapy interventions using highly standardized intervention protocols, although methodologically rigorous, do not necessarily reflect "real-world" clinical practice, and in many cases results have been disappointing. Development of a complex intervention that includes multiple treatment modalities and individualized treatment technique selection requires a systematic approach to designing all aspects of the intervention based on theory, evidence, and practical constraints. This perspective article outlines the development of the rationale and structure of a multimodal physical therapy program for painful hip osteoarthritis to be assessed in a clinical trial. The resulting intervention protocol comprises a semi-structured program of exercises and manual therapy, advice, physical activity, and optional prescription of a gait aid that is standardized, yet can be individualized according to physical assessment and radiographic findings. The program is evidence based and reflects contemporary physical therapist practice, while also being reproducible and reportable. This perspective article aims to encourage physical therapy researchers involved in evaluation of complex interventions to better document their own intervention development, as well as the outcomes, thus generating a body of knowledge about the development processes and protocols that is generalizable to the real-world complexity of providing physical therapy to individual patients.

Potential loss of muscle function during dynamic actions caused by significantly decreased muscle strength in older women with hip osteoarthritis

PURPOSE

The aim of the study was to analyze the results of the hip joint torques within the patients with osteoarthritis (OA). A total of 119 women were divided into 3 groups performing 3 dimensional strength tests. For the measurements a new apparatus was invented and used. Specially designed position was safety and comfortable during testing OA and elderly women.

RESULTS

Significant differences (p≤0.05) in strength tests were found both between body side and muscle groups in most of the performed tests. The biggest unilateral deficit in OA group was found in muscles most important for gait and weight bearing − 0.55 for both flexors and extensors. Surprisingly no lateral difference was found for the hip joint adductors. Analysis of the correlation coefficient between the hip joint muscles proved that complex movements needed well-developed coordination between the muscle groups. The most important agonist muscle coordination occurs between hip extensors and abductors − 0.68 to 0.80.

CONCLUSION

Unilateral hip OA affecting older women is directly responsible for significantly lower muscle strength when compared with both control groups. Lost of balance and coordination needed for dynamic actions like gait is caused by strength asymmetry of crucial hip muscles as well as near zero correlation between important agonist muscles.