Lower limb muscle strengthening does not change frontal plane moments in women with knee osteoarthritis: A randomized controlled trial

Efficacy of lower limb strengthening exercises based on different muscle contraction characteristics for knee osteoarthritis: a systematic review and network meta-analysis

Purpose

While strengthening exercises are recommended for knee osteoarthritis (KOA) treatment, the optimal type of muscle contraction remains unclear, with current research showing conflicting results. This network meta-analysis (NMA) aims to evaluate the efficacy of lower limb strengthening exercises based on different muscle contraction characteristics for KOA patients and provide clinical references.

Methods

We conducted the NMA following the PRISMA-NMA. A comprehensive search of five databases (PubMed, Web of Science, CENTRAL, Embase, and SPORTDiscus) up to August 2024 identified randomized controlled trials (RCTs) investigating lower limb strengthening exercises in KOA patients. Control groups included receiving usual care, only providing health education, or no intervention at all. Outcomes analyzed included pain, physical function, quality of life, and muscle strength.

Results

Forty-one studies (2,251 participants) were included. Twenty-eight studies used rigorous randomization; eighteen reported allocation concealment. All had high performance bias risk due to exercise interventions. Regarding efficacy, isokinetic exercise ranked highest in pain relief (SMD = 0.70, 95% CI: 0.50-0.91, SUCRA = 82.6%), function improvement (SMD = 0.75, 95% CI: 0.57-0.92, SUCRA = 96.1%), and enhancement in muscle strength (SMD = 0.56, 95% CI: 0.34-0.78, SUCRA = 90.1%). Isometric exercise ranked highest in improving quality of life (SMD = 0.80, 95% CI: 0.28-1.31, SUCRA = 90.5%). Mixed strengthening exercise ranked lowest across all outcomes. High-frequency interventions (≥5 times/week) showed superior pain relief compared with low-frequency (≤3 times/week) for isotonic, isometric, and isokinetic exercise.

Conclusion

This NMA suggests isokinetic exercise may be most effective for pain, function, and muscle strength in KOA patients, while isometric exercise benefits quality of life most. Mixed strengthening exercise ranked lowest across all outcomes. High-frequency interventions appear more effective than low-frequency ones. These findings support personalized KOA treatment, considering efficacy, accessibility, and patient-specific factors. Study biases, heterogeneity, and other limitations may affect result reliability. Future research should focus on high-quality studies with standardized protocols and analyze dose-response relationships to refine KOA treatment strategies.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024582525, identifier: CRD42024582525.

Knowledge mapping and bibliometric analysis of medical knee magnetic resonance imaging for knee osteoarthritis (2004-2023)

Objectives

Magnetic resonance imaging (MRI) is increasingly used to detect knee osteoarthritis (KOA). In this study, we aimed to systematically examine the global research status on the application of medical knee MRI in the treatment of KOA, analyze research hotspots, explore future trends, and present results in the form of a knowledge graph.

Methods

The Web of Science core database was searched for studies on medical knee MRI scans in patients with KOA between 2004 and 2023. CiteSpace, SCImago Graphica, and VOSviewer were used for the country, institution, journal, author, reference, and keyword analyses.

Results

A total of 2,904 articles were included. The United States and Europe are leading countries. Boston University is the main institution. Osteoarthritis and cartilage is the main magazine. The most frequently cocited article was "Radiological assessment of osteoarthrosis". Guermazi A was the author with the highest number of publications and total references. The keywords most closely linked to MRI and KOA were "cartilage", "pain", and "injury".

Conclusions

The application of medical knee MRI in KOA can be divided into the following parts: (1). MRI was used to assess the relationship between the characteristics of local tissue damage and pathological changes and clinical symptoms. (2).The risk factors of KOA were analyzed by MRI to determine the early diagnosis of KOA. (3). MRI was used to evaluate the efficacy of multiple interventions for KOA tissue damage (e.g., cartilage defects, bone marrow edema, bone marrow microfracture, and subchondral bone remodeling). Artificial intelligence, particularly deep learning, has become the focus of research on MRI applications for KOA.

Evaluation of lumbar and hip movement characterization and muscle activities during gait in patients with knee osteoarthritis

Patients with knee osteoarthritis (KOA) might have gait deviations, but few previous studies have discussed gait compensatory movements of the proximal and distal parts of muscle groups related to KOA. The study aimed to measure lumbar and hip movements during gait test and collect muscle activities of the lower extremities. Thirty-four participants with KOA and 28 healthy participants aged over 50 years were recruited for this study. Lumbar and hip motions during walking test were measured using inertial measurement units. Four muscle groups of the lower extremity (erector spinae, gluteus maximus, quadriceps muscle, and gastrocnemius) activities in gait were collected using surface EMGs. KOA patients used an 2.12∘anterior inclined lumbar spine (p = 0.007) and 22.94∘ flexed hip (p = 0.001) in gait compared to healthy participants. The KOA patients had a small hip movement range 30.19∘(p = 0.001) and a higher asymmetric stance time ratio 0.39 (p = 0.006). Patients with KOA showed decreased erector spinae and gluteus maximus muscle activation and increased activation of the quadriceps and gastrocnemius muscles during gait. In conclusion, patients with KOA used a hyperlordotic lumbar and hip flexed strategy, which overactivates distal extensor muscles through the whole gait and might cause overstress on the lower extremity joints.

Dose-Response Relationships of Resistance Training in Adults With Knee Osteoarthritis: A Systematic Review and Meta-analysis

BACKGROUND AND PURPOSE

To determine the effects of resistance training (RT) on symptoms, function, and lower limb muscle strength in patients with knee osteoarthritis (KOA), and to determine the optimal dose-response relationships.

DATA SOURCES

We searched the PubMed, MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and ClinicalTrials.gov databases from inception to January 23, 2022.

ELIGIBILITY CRITERIA

Randomized controlled trials that examined the effects of RT in KOA patients (mean age ≥50 years) were included.

DATA SYNTHESIS

We applied Hedges' g of the random-effects model to calculate the between-subject standardized mean difference (SMDbs). A random-effects metaregression was calculated to explain the influence of key training variables on the effectiveness of RT. We used the Grading of Recommendations Assessments, Development and Evaluation (GRADE) method to appraise the certainty of evidence.

RESULTS

A total of 46 studies with 4289 participants were included. The analysis revealed moderate effects of RT on symptoms and function (SMDbs =-0.52; 95% CI: -0.64 to -0.40), and lower limb muscle strength (SMDbs = 0.53; 95% CI: 0.42 to 0.64) in the intervention group compared with the control group. The results of the metaregression revealed that only the variable "training period" (P< .001) had significant effects on symptoms, function, and lower limb muscle strength, and the 4 to 8 weeks of training subgroup showed greater effects than other subgroups (SMDbs =-0.70, -0.91 to -0.48; SMDbs = 0.76, 0.56 to 0.96).

CONCLUSIONS

Compared with inactive treatments, RT is strongly recommended to improve symptoms, function, and muscle strength in individuals with KOA. Dose-response relationship analysis showed that 4 to 8 weeks of RT had more benefits.

Do Interlimb Knee Joint Loading Asymmetries Persist throughout Stance during Uphill Walking Following Total Knee Arthroplasty?

The purpose of this study was to determine differences in total (TCF), medial compartment (MCF), and lateral compartment (LCF) tibiofemoral joint compressive forces and related muscle forces between replaced and non-replaced limbs during level and uphill walking at an incline of 10°. A musculoskeletal modeling and simulation approach using static optimization was used to determine the muscle forces and TCF, MCF, and LCF for 25 patients with primary TKA. A statistical parametric mapping repeated-measures ANOVA was conducted on knee compressive forces and muscle forces using statistical parametric mapping. Greater TCF, MCF, and LCF values were observed throughout the loading response, mid-stance, and late stance during uphill walking. During level walking, knee extensor muscle forces were greater throughout the first 50% of the stance during level walking, yet greater during uphill walking during the last 50% of the stance. Conversely, knee flexor muscle forces were greater through the loading response and push-off phases of the stance. No between-limb differences were observed for compressive or muscle forces, suggesting that uphill walking may promote a more balanced loading of replaced and non-replaced limbs. Additionally, patients with TKA appear to rely on the hamstrings muscle group during the late stance for knee joint control, thus supporting uphill walking as an effective exercise modality to improve posterior chain muscle strength.

Exploring the modification factors of exercise therapy on biomechanical load in patients with knee osteoarthritis: a systematic review and meta-analysis

The objective of this systematic review and meta-analysis is to clarify the effect of exercise therapy on the first peak knee adduction moment (KAM), as well as other biomechanical loads in patients with knee osteoarthritis (OA), and identify physical characteristics that influence differences in biomechanical load after exercise therapy. The data sources are PubMed, PEDro, and CINAHL, from study inception to May 2021. The eligibility criteria include studies evaluating the first peak (KAM), peak knee flexion moment (KFM), maximal knee joint compression force (KCF), or co-contraction during walking before and after exercise therapy in patients with knee OA. The risk of bias was independently assessed by two reviewers using PEDro and NIH scales. Among 11 RCTs and nine non-RCTs, 1119 patients with knee OA were included (average age: 63.7 years). As the results of meta-analysis, exercise therapy tended to increase the first peak KAM (SMD 0.11; 95% CI: -0.03-0.24), peak KFM (SMD 0.13; 95% CI: -0.03-0.29), and maximal KCF (SMD 0.09; 95% CI -0.05-0.22). An increased first peak KAM was significantly associated with a larger improvement in knee muscle strength and WOMAC pain. However, the quality of evidence regarding the biomechanical loads was low-to-moderate according to the GRADE approach. The improvement in pain and knee muscle strength may mediate the increase in first peak KAM, suggesting difficulty in balancing symptom relief and biomechanical load reduction. Therefore, exercise therapy may satisfy both aspects simultaneously when combined with biomechanical interventions, such as a valgus knee brace or insoles. Registration: PROSPERO (CRD42021230966).

Tibiofemoral compressive force during downhill walking in patients with primary total knee arthroplasty: A statistical parametric mapping approach

BACKGROUND

Downhill walking is a necessary part of daily life and an effective activity in post-operative rehabilitation following total knee arthroplasty. The purpose of this study was to determine differences in the behavior of total, medial, and lateral tibiofemoral compressive forces as well as knee extensor and flexor muscle forces between different limbs of patients with total knee arthroplasty (replaced, non-replaced) during downhill and level walking.

METHODS

Musculoskeletal modeling and simulation were implemented to determine muscle forces and tibiofemoral compressive forces in 25 patients with total knee arthroplasty. A 2 × 2 [Limb (replaced, non-replaced) × Slope (0°, 10°)] Statistical parametric mapping repeated measures analysis of variance was conducted on selected variables.

FINDINGS

Statistical parametric mapping did not identify any between-limb differences for compressive or muscle forces. Differences in joint compressive and muscle forces persisted throughout different intervals of stance-phase between level and downhill walking. Knee extensor muscle forces were distinctly greater during level walking for nearly all of stance phase. Knee flexor muscle force was greater during downhill walking for >60% of stance. Statistical parametric mapping did identify regions of significance between level and downhill walking that coincided temporally (near loading response and push off) with peak joint moment and joint compressive forces traditionally reported using discrete variable analyses.

INTERPRETATION

Downhill walking may be a safe and useful rehabilitation tool for post-knee arthroplasty rehabilitation that will not disproportionally load either the replaced or the non-replaced joint and where the quadriceps muscles can be strengthened during a gait-specific task.

Efficacy of rectus femoris stretching on pain, range of motion and spatiotemporal gait parameters in patients with knee osteoarthritis: a randomised controlled trial

OBJECTIVE

This study aimed to investigate the efficacy of rectus femoris stretching on pain intensity, knee range of motion (ROM), spatiotemporal gait parameters and function in patients with knee osteoarthritis (KOA).

METHODS

This parallel group, single-blinded randomised controlled trial was conducted in two outpatient physical therapy clinics. Study participants (n=60, with age>45 years) with mild-to-moderate bilateral KOA were randomised into the study group (SG) and control group (CG). SG received rectus femoris stretching exercises together with stretching exercises of the calf, hamstring and iliotibial band, strength exercises for the quadriceps, gluteus medius, gluteus maximus and calf muscles, whereas, the CG received all exercises mentioned for SG except rectus femoris stretching. Pain intensity, ROM, spatiotemporal gait parameters and function were measured before and after 4 weeks of treatment.

RESULTS

The SG showed a significant improvement in the visual analogue scale, Western Ontario and McMaster Universities measure and ROM (p<0.001). The SG also had a significantly greater step length and speed than CG (p<0.001). Extension ROM did not significant difference between the groups (p>0.05).

CONCLUSION

Simple rectus femoris stretching exercises are easy to perform even at home and are beneficial for pain, flexion ROM, function and spatiotemporal gait parameters, such as step length and speed, in KOA patients if the compliance with the exercise regimen is good.

TRIAL REGISTRATION NUMBER

Pan African Clinical Trials Registry PACTR202003828737019.

Variability in effect sizes of exercise therapy for knee osteoarthritis depending on comparator interventions

BACKGROUND

Systematic reviews of exercise therapy for knee osteoarthritis (OA) have largely ignored the variability in comparator interventions.

OBJECTIVE

To assess how effect estimates of exercise therapy for knee OA as reported in randomized controlled trials vary depending on the comparator interventions.

METHODS

We followed the Cochrane Handbook and PRISMA guidance to conduct and report this meta-epidemiological study. Randomised controlled trials (RCTs) were identified from systematic reviews published in 2015 or later and reference lists of included studies. Exercise therapy RCTs testing interventions that adhered to the American College of Sports Medicine (ACSM) guidelines compared to any comparator intervention in people with knee OA and reporting outcomes of knee pain, physical function and/or quadriceps strength at the end of intervention were included.

RESULTS

Thirty-five RCTs with 2412 participants were included. Comparator interventions included no intervention, non-ACSM compliant exercise therapy, education/self-management, and passive modalities. For pain, standardized mean difference (SMD) for ACSM compliant exercise therapy compared to passive modalities was 1.76 (95% CI 0.49, 3.04), no intervention 0.93 (95% CI 0.50; 1.36), education/self-management 0.27 (95% CI 0.07, 0.47), and non-ACSM compliant exercise therapy 0.09 (95% CI -0.06, 0.23). For physical function, SMD for ACSM compliant exercise therapy compared to passive modalities was 1.29 (95% CI 0.41, 2.17), no intervention 0.76 (95% CI 0.15, 1.36), non-ACSM compliant exercise therapy 0.25 (95% CI -0.00, 0.51) and education/self-management 0.21 (95% CI -0.14, 0.55). For quadriceps strength, SMD for ACSM compliant exercise therapy compared to no intervention was 0.69 (95% CI 0.42, 0.96), non-ACSM compliant exercise therapy 0.23 (95% CI -0.01, 0.46), education/self-management -0.02 (95% CI -0.45, 0.42) and passive modalities 0.80 (95% CI -0.10, 1.71).

CONCLUSION

The effect of exercise therapy for knee OA varies significantly depending on the comparator intervention. This variability should be assessed routinely in systematic reviews.

A recommended exercise program appropriate for patients with knee osteoarthritis: A systematic review and meta-analysis

Background: Knee osteoarthritis (KOA) is a common degenerative disease. Recommended first-line management includes exercise. However, there is still no standard recommendation for the appropriate exercise program for patients with KOA.

Purpose: This study aims to compare the effects of a land-based exercise program with high vs. uncertain compliance with recommendations among people with KOA in pain, function, and stiffness.

Methods: From January 2000 to January 2022, PubMed, EBSCO, Sport-discuss, Medline, and Web of Science were searched. A comprehensive review of meta-analyses of land-based exercise programs with exercise prescriptions was done in symptomatic individuals with KOA. The Cochrane Collaboration’s standards were followed for study selection, eligibility criteria, data extraction, and statistics, and the Cochrane Collaboration’s tool was used to assess the risk of bias. Review Manager 5 software was used to extract the baseline mean and follow-up values, as well as the accompanying standard deviation, to calculate the standardized mean difference (SMD). In meta-analyses, SMD was calculated for pain outcomes, self-reported physical function, and stiffness. The effects of the outcomes on the subgroups of studies were compared. A fixed- or random-effects model was used in group research studies with comparable outcomes.

Results: There were 15 studies with a total of 1,436 participants. Compliance with the ACSM recommendations was categorized as “high” in five cases and “uncertain” in nine others. The SMD for pain was −0.31 (95% CI −0.47, −0.14) in the subgroup with a high ACSM compliance ratio and −0.55 (95% CI −0.69, −0.41) in the subgroup with uncertain ACSM compliance. For physical function, in the high-compliance group, the SMD was −0.21 (95% CI −0.38, −0.05), while in the uncertain-compliance group, it was −0.61 (95 % CI −0.82, −0.40). The SMD was −0.40 (95 % CI −0.61, −0.19) for stiffness and high compliance with ACSM. The SMD was −0.29 (95% CI −0.66, 0.07) for study interventions with uncertain compliance.

Conclusion: The results showed that the land-based training program significantly improved pain, physical function, and stiffness in KOA patients compared to controls. Exercise interventions with high adherence to ACSM recommendations differed significantly only in stiffness measures compared with the uncertain-compliance group.

Clinical Trial Registration:https://www.crd.york.ac.uk/prospero/#recordDetails, identifier PROSPERO (ID CRD42022311660)

Physical therapy and orthopaedic equipment-induced reduction in the biomechanical risk factors related to knee osteoarthritis: a systematic review and Bayesian network meta-analysis of randomised controlled trials

OBJECTIVE

Are physical therapy or orthopaedic equipment efficacious in reducing the biomechanical risk factors in people with tibiofemoral osteoarthritis (OA)? Is there a better therapeutic intervention than others to improve these outcomes?

DESIGN

Systematic review with network meta-analysis (NMA) of randomised trials.

DATA SOURCES

PubMed, Web of Science, Cochrane Library, Embase and MEDLINE were searched through January 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included randomised controlled trials exploring the benefits of using physical therapy or orthopaedic equipment in reducing the biomechanical risk factors which included knee adduction moment (KAM) and knee adduction angular impulse (KAAI) in individuals with tibiofemoral OA.

DATA EXTRACTION AND SYNTHESIS

Two authors extracted data independently and assessed risk of bias. We conducted an NMA to compare multiple interventions, including both direct and indirect evidences. Heterogeneity was assessed (sensitivity analysis) and quantified (I2 statistic). Grading of Recommendations Assessment, Development and Evaluation assessed the certainty of the evidence.

RESULTS

Eighteen randomised controlled trials, including 944 participants, met the inclusion criteria, of which 14 trials could be included in the NMA. Based on the collective probability of being the overall best therapy for reducing the first peak KAM, lateral wedge insoles (LWI) plus knee brace was closely followed by gait retraining, and knee brace only. Although no significant difference was observed among the eight interventions, variable-stiffness shoes and neuromuscular exercise exhibited an increase in the first peak KAM compared with the control condition group. And based on the collective probability of being the overall best therapy for reducing KAAI, gait retraining was followed by LWI only, and lower limb exercise.

CONCLUSION

The results of our study support the use of LWI plus knee brace for reducing the first peak KAM. Gait retraining did not rank highest but it influenced both KAM and KAAI and therefore it was the most recommended therapy for reducing the biomechanical risk factors.

Use of rating of perceived exertion during anterior cruciate ligament reconstruction and knee osteoarthritis rehabilitation: a scoping review protocol

INTRODUCTION

Anterior cruciate ligament (ACL) tear and knee osteoarthritis (KOA) are the most prevalent musculoskeletal disorders of the knee. Rehabilitation with progressive resistance training is recommended for both disorders. Rating of perceived exertion (RPE) is widely used to prescribe, monitor, and control exercise load. However, the lack of detailed methodological description and variability in the use of RPE may hinder its validity. This scoping review summarises methodological aspects of the use of RPE in resistance exercises during ACL reconstruction and KOA rehabilitation. We also aim to identify possible methodological issues related to the use of RPE and provide recommendations for future studies.

METHODS AND ANALYSIS

This scoping review protocol was developed following the Joanna Briggs Institute and Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement extension for Scoping Reviews. The search will be conducted in Medline/PubMed, Embase, CINAHL, PEDro, Central and SPORTDiscus databases. The terms "anterior cruciate ligament rehabilitation", "knee osteoarthritis" and "resistance exercise" and their synonymous will be used isolated and combined (boolean operators AND/OR/NOT). Two reviewers will independently conduct title and abstract screening and evaluate full texts of potentially eligible articles. Data related to study design, sample, intervention characteristics and RPE outcomes will be extracted, summarised and qualitatively analysed.

ETHICS AND DISSEMINATION

The proposed scoping review does not require ethical approval since it will synthesise information from publicly available studies. Regarding dissemination activities, results will be submitted for publication in a scientific journal and presented at conferences in the field.

The Relationship Between Changes in Movement and Activity Limitation or Pain in People With Knee Osteoarthritis: A Systematic Review

OBJECTIVE

To report whether changes in knee joint movement parameters recorded during functional activities relate to change in activity limitation or pain after an exercise intervention in people with knee osteoarthritis (OA).

DESIGN

Etiology systematic review.

LITERATURE SEARCH

Four databases (MEDLINE, Embase, CINAHL, and AMED) were searched up to January 22, 2021.

STUDY SELECTION CRITERIA

Randomized controlled trials or cohort studies of exercise interventions for people with knee OA that assessed change in knee joint movement parameters (moments, kinematics, or muscle activity) and clinical outcomes (activity limitation or pain).

DATA SYNTHESIS

A descriptive synthesis of functional activities, movement parameters, and clinical outcomes.

RESULTS

From 3182 articles, 22 studies met the inclusion criteria, and almost all were of low quality. Gait was the only investigated functional activity. After exercise, gait parameters changed 26% of the time, and clinical outcomes improved 90% of the time. A relationship between group-level changes in gait parameters and clinical outcomes occurred 24.5% of the time. Two studies directly investigated an individual-level relationship, reporting only 1 significant association out of 8 correlations tested.

CONCLUSION

Most studies reported no change in gait-related movement parameters despite improvement in clinical outcomes, challenging the belief that changing movement parameters is always clinically important in people with knee OA. J Orthop Sports Phys Ther 2021;51(10):492-502. doi:10.2519/jospt.2021.10418.

Effects of resistance training on gait velocity and knee adduction moment in knee osteoarthritis patients: a systematic review and meta-analysis

The systematic review aimed to analyze the effects of resistance training in knee osteoarthritis (OA) rehabilitation from a biomechanical perspective. A meta-analysis was performed to determine the potential benefits of resistance training on patients with knee OA. Relevant studies based on the inclusion and exclusion criteria were selected from CENTRAL, PubMed, Scopus, and Web of Science databases inception to August 2020. Outcome measures included gait velocity and knee adduction moment (KAM). The mean differences of the data with a 95% confidence interval were analyzed using STATA 15.1 software The search identified eight studies that satisfied all the inclusion criteria, in which 164 patients were involved in gait velocity studies and another 122 patients were part of KAM studies. Analysis of the pooled data showed that resistance training significantly improved the gait velocity in patients with knee OA (p < 0.01, z = 2.73), ES (95% CI) = 0.03 (0.01, 0.06) m/s. However, resistance training had no significant effect on improving KAM in patients with knee OA (p = 0.98, z = 0.03), ES (95% CI) = 0.00 (− 0.16, 0.16) percentage of body weight × height (%BW × Ht). Therefore, resistance training may enhance gait velocity but not KAM in knee OA patients. The protocol was registered at PROSPERO (registration number: CRD42020204897).

Effects of an Exercise Therapy Targeting Knee Kinetics on Pain, Function, and Gait Kinetics in Patients With Knee Osteoarthritis: A Randomized Clinical Trial

In this study, the effects of an exercise therapy comprising yoga exercises and medial-thrust gait (YogaMT) on lower-extremity kinetics, pain, and function in patients with medial knee osteoarthritis were investigated. Fifty-nine patients were randomly allocated to three treatment groups: (a) the YogaMT group practiced yoga exercises and medial thrust gait, (b) the knee-strengthening group performed quadriceps- and hamstring-strengthening exercises, and (c) the treadmill walking group practiced normal treadmill walking in 12 supervised sessions. The adduction and flexion moments of the hip, knee, and ankle; pain intensity; and 2-min walking test were assessed before and after treatment and at 1-month follow-up. The YogaMT group experienced a significant reduction in knee adduction moment. All groups showed significant improvement in pain and function. The YogaMT may reduce medial knee load in patients with knee osteoarthritis in the short term. A larger clinical trial is required to investigate the long-term outcomes of this intervention.

Efficacy of Specified Manual Therapies in Combination with a Supervised Exercise Protocol for Managing Pain Intensity and Functional Disability in Patients with Knee Osteoarthritis

PURPOSE

The current study aimed to determine the efficacy of specified manual therapies in combination with a supervised exercise protocol for managing pain intensity and functional disability in patients with knee osteoarthritis.

METHODS

The study was based on a two-arm parallel-group randomized controlled trial design, including a total of 32 participants with knee osteoarthritis randomly divided into groups A and B. Group A received a supervised exercise protocol; however, group B received specified manual therapies in combination with a supervised exercise protocol. Pain and functional disability were measured with the numeric pain rating scale (NPRS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), respectively. Data were collected at baseline (pre-intervention), 2 weeks, and 4 weeks post-intervention. To evaluate the efficacy of specific manual therapies with supervised exercise compared to supervised exercise alone, an unpaired t-test and repeated measures ANOVA were used to analyze the data, keeping the level of significance at p<0.05.

RESULTS

A significant (p<0.05) mean difference (∆MD) was found within group A and group B for both outcomes when we compared their baseline scores with 2-week (group A, NPRS: ∆MD=-1.56 and WOMAC: ∆MD=14.94; group B, NPRS: ∆MD=2.06 and WOMAC: ∆MD=22.19) and 4-week post-intervention scores (group A, NPRS: ∆MD=0.62 and WOMAC: ∆MD=6.75; group B, NPRS: ∆MD=0.75 and WOMAC: ∆MD=11.12). In addition, significant mean differences (p<0.05) reported for both outcomes when we compared their scores between groups A and B at 2 weeks (∆MD: NPRS=0.69; WOMAC=10.87) and 4 weeks post-intervention (∆MD: NPRS=0.31; WOMAC=8.00). Furthermore, a post hoc Scheffe analysis for the outcomes NPRS and WOMAC revealed the superiority of group B over group A.

CONCLUSION

The specified manual therapies, in combination with a supervised exercise protocol, were found to be more effective than a supervised exercise protocol alone for improving pain and functional disability in patients with knee osteoarthritis.

Hip Muscle Strengthening for Knee Osteoarthritis: A Systematic Review of Literature

BACKGROUND AND PURPOSE

Osteoarthritis (OA) of the knee joint results in chronic pain and functional decline among older adults. Hip muscle weakness has been observed in persons with knee OA and is claimed to increase the medial compartment loading on the knee joint. Although individual studies are available, no review has yet integrated the literature on the benefits of hip muscle strengthening for persons with knee OA. This review aims to systematically summarize the current evidence on the effectiveness of hip muscle strengthening on knee pain, lower extremity function, and biomechanical measures of the knee in persons with knee OA.

METHODS

An extensive electronic literature search was conducted in the databases PubMed, Scopus, Cumulative Index to Nursing and Allied Health (CINAHL), Cochrane Central Register of Controlled Trials (CENTRAL), and Physiotherapy Evidence Database (PEDro) to identify the published trials in the English language from January 1990 to August 2017. Randomized controlled trials that studied the effectiveness of hip muscle strengthening in persons with knee OA on knee pain, physical function, and biomechanical measures of the knee were considered for inclusion. The key word combinations were knee osteoarthritis, degenerative arthritis, arthralgia, muscle strengthening, and resistance training using the Boolean operators AND, OR. Two reviewers independently performed the study selection, and a third reviewer intervened when the consensus was not attained. Quality assessment of the included studies was carried out using the PEDro scale.

RESULTS AND DISCUSSION

The search produced 774 results, from which 81 full-text articles were studied. Five randomized controlled trials of good methodological quality, including 331 participants, were included in the review. The effectiveness of hip muscle strengthening was assessed in isolation, combination, and comparison with other lower extremity exercise. Overall, the studies reported clear benefits of hip muscle strengthening on knee pain, physical function, and hip muscle strength. However, hip muscle strengthening was ineffective in improving the biomechanical measures such as dynamic alignment and knee adduction (also known as valgus) moment.

CONCLUSION

The current review identified strong, high-quality evidence to recommend hip muscle strengthening in the conservative management of persons with knee OA. Further research is needed to establish the underlying mechanisms for the clinical benefits.

Eccentric and Concentric Resistance Exercise Comparison for Knee Osteoarthritis

INTRODUCTION

This study aimed to compare the efficacy of eccentrically focused resistance exercise (ECC RT) to concentrically focused resistance exercise (CNC RT) on knee osteoarthritis (OA) symptoms and strength.

METHODS

Ninety participants consented. Participants were randomized to CNC RT, ECC RT, or a wait-list, no-exercise control group. Four months of supervised exercise training was completed using traditional weight machines (CNC RT) or modified-matched machines that overloaded the eccentric action (ECC RT). Main outcomes included one-repetition maximal strength (knee extension, leg flexion, and leg press), weekly rate of strength gain, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) total score and subscores.

RESULTS

Fifty-four participants (60-85 yr, 61% women) completed the study. Both CNC RT and ECC RT groups showed 16%-28% improvement relative to the wait-list, no-exercise control group (P = 0.003-0.005) for all leg strength measures. The rate of weekly strength gain was greater for CNC RT than for ECC RT for leg press and knee flexion (by 2.9%-4.8%; both, P < 0.05) but not knee extension (0.7%; P = 0.38). There were no significant differences in WOMAC total and subscores across groups over time. Leg press strength change was the greatest contributor to change in WOMAC total scores (R = 0.223). The change in knee flexion strength from baseline to month 4 was a significant predictor of the change in WOMAC pain subscore (F ratio = 4.84, df = 45, P = 0.032). Both modes of strength training were well tolerated.

CONCLUSIONS

Both resistance training types effectively increased leg strength. Knee flexion and knee extension muscle strength can modify function and pain symptoms irrespective of muscle contraction type. Which mode to pick could be determined by preference, goals, tolerance to the contraction type, and equipment availability.

Concentric and Eccentric Resistance Training Comparison on Physical Function and Functional Pain Outcomes in Knee Osteoarthritis: A Randomized Controlled Trial

OBJECTIVE

The aim of the study was to compare the effectiveness of concentrically focused resistance training to eccentrically focused resistance training on physical function and functional pain in knee osteoarthritis.

DESIGN

This is a randomized, single-blinded controlled 4-mo trial. Older adults with knee osteoarthritis (N = 88; 68.3 ± 6.4 yrs, 30.4 ± 6.9 kg/m, and 67.4% women) were randomized to eccentrically focused resistance training, concentrically focused resistance training, or no-exercise control. Main outcomes included chair rise time, stair climb time, 6-min walk test distance, temporal-spatial parameters of gait, community ambulation, and functional pain.

RESULTS

Leg muscle strength improved in both training groups compared with no-exercise control. There were no significant group × time interactions for any functional performance score (chair rise time, stair climb time, 6-min walk test distance, gait parameters, community ambulation). Compared with no-exercise control, functional pain scores were reduced for chair rise (-38.6% concentrically focused resistance training, -50.3% eccentrically focused resistance training vs. +10.0%) and stair climb (-51.6% concentrically focused resistance training, -41.3% eccentrically focused resistance training vs. +80.7%; all P < 0.05). Pain scores were reduced during the 6-min walk and in early recovery with concentrically focused resistance training compared with the remaining two groups (P < 0.05).

CONCLUSIONS

Either resistance exercise type improves activity-related knee osteoarthritis pain, but concentrically focused resistance training more effectively reduced severity of ambulatory pain and pain upon walking cessation.

Does low back pain or leg pain in gluteus medius syndrome contribute to lumbar degenerative disease and hip osteoarthritis and vice versa? A literature review

[Purpose] Gluteus medius syndrome is one of the major causes of back pain or leg pain and is similar to greater trochanteric pain syndrome, which also presents with back pain or leg pain. Greater trochanteric pain syndrome is associated with lumbar degenerative disease and hip osteoarthritis. The objective of this review was to demonstrate gluteus medius syndrome as a disease entity by reviewing relevant articles to elucidate the condition. [Methods] Gluteus medius syndrome was defined as myofascial pain syndrome arising from the gluteus medius. We performed a search of the literature using the following keywords: “back pain”, “leg pain”, “greater trochanteric pain syndrome”, “degenerative lumbar disease”, “hip osteoarthritis”, and “gluteus medius”. We reviewed articles related to gluteus medius syndrome and described the findings in terms of diagnosis and treatment based on the underlying pathology. [Results] A total of 135 articles were included in this review. Gluteus medius syndrome is similar as a disease entity to greater trochanteric pain syndrome, which presents with symptoms of low back pain and leg pain. Gluteus medius syndrome is also related to lumbar degenerative disease, hip osteoarthritis, knee osteoarthritis, and failed back surgery syndrome. [Conclusion] Accurate diagnosis of gluteus medius syndrome and appropriate treatment could possibly improve lumbar degenerative disease and osteoarthritis of the hip and knee, as well as hip-spine syndrome and failed back surgery syndrome.

The Role of Resistance Training Dosing on Pain and Physical Function in Individuals With Knee Osteoarthritis: A Systematic Review

CONTEXT

Dosing parameters are needed to ensure the best practice guidelines for knee osteoarthritis.

OBJECTIVE

To determine whether resistance training affects pain and physical function in individuals with knee osteoarthritis, and whether a dose-response relationship exists. Second, we will investigate whether the effects are influenced by Kellgren-Lawrence grade or location of osteoarthritis.

DATA SOURCES

A search for randomized controlled trials was conducted in MEDLINE, Embase, and CINAHL, from their inception dates, between November 1, 2018, and January 15, 2019. Keywords included knee osteoarthritis, knee joint, resistance training, strength training, and weight lifting.

STUDY SELECTION

Inclusion criteria were randomized controlled trials reporting changes in pain and physical function on humans with knee osteoarthritis comparing resistance training interventions with no intervention. Two reviewers screened 471 abstracts; 12 of the 13 studies assessed were included.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 2.

DATA EXTRACTION

Mean baseline and follow-up Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores and standard deviations were extracted to calculate the standard mean difference. Articles were assessed for methodological quality using the CONSORT (Consolidated Standards of Reporting Trials) 2010 scale and Cochrane Collaboration tool for assessing risk of bias.

RESULTS

The 12 included studies had high methodological quality. Of these, 11 studies revealed that resistance training improved pain and/or physical function. The most common regimen was a 30- to 60-minute session of 2 to 3 sets of 8 to 12 repetitions with an initial resistance of 50% to 60% of maximum resistance that progressed over 3 sessions per week for 24 weeks. Seven studies reported Kellgren-Lawrence grade, and 4 studies included osteoarthritis location.

CONCLUSION

Resistance training improves pain and physical function in knee osteoarthritis. Large effect sizes were associated with 24 total sessions and 8- to 12-week duration. No optimal number of repetitions, maximum strength, or frequency of sets or repetitions was found. No trends were identified between outcomes and location or Kellgren-Lawrence grade of osteoarthritis.

Rehabilitation Exercises for the Gluteus Minimus Muscle Segments: An Electromyography Study

CONTEXT

The gluteus minimus (GMin) muscle consists of 2 uniquely oriented segments that have potential for independent function and have different responses to pathology and aging. For healthy young adults, it is unknown that which rehabilitation exercises specifically target the individual segments.

OBJECTIVE

To quantify segmental GMin activity for 6 common lower-limb rehabilitation exercises in healthy young adults and determine if significant differences exist in segmental activity levels between the exercises.

METHOD

Six common lower-limb rehabilitation exercises were performed by 10 healthy young adults with fine-wire electromyography (EMG) electrodes inserted into the anterior and posterior segments of the GMin muscle.

MAIN OUTCOME MEASURES

Electromyography signals were recorded, and median normalized exercise activity levels were reported and compared for each GMin segment across the 6 exercises.

RESULTS

High activity levels were generated in the anterior segment by the resisted hip abduction-extension exercise (51% maximum voluntary isometric contraction [MVIC]), whereas for the posterior segment, high activity levels were produced by the single-leg bridge (49% MVIC), the side-lie hip abduction (43% MVIC), the resisted hip abduction-extension exercise (43% MVIC), and the single-leg squat (40% MVIC). There were significant differences (P < .05) in the median electromyography activity levels for the anterior GMin segment but not for the posterior GMin segment across some of the exercises with large effect sizes.

CONCLUSION

Targeted rehabilitation exercises graded by exercise intensity can be prescribed specifically for the anterior and posterior GMin segments to aid in restoration of hip function following injury or aging.

Pelvic Drop Changes due to Proximal Muscle Strengthening Depend on Foot-Ankle Varus Alignment

Background

Strengthening of hip and trunk muscles can modify pelvis and hip movements. However, the varus alignment of the foot-ankle complex (FAC) may influence the effects of muscle strengthening, due to the relationship of FAC alignment with pelvic and hip kinematics. This study evaluated the effects of hip and trunk muscle strengthening on pelvis and hip kinematics during walking, in subgroups with larger and smaller values of FAC varus alignment. In addition, this study evaluated the effects of hip and trunk muscle strengthening on hip passive and active properties, in the same subgroups.

Methods

Fifty-three women, who were divided into intervention and control groups, participated in this nonrandomized controlled trial. Each group was split into two subgroups with larger and smaller values of FAC varus alignment. Hip and trunk muscle strengthening was performed three times a week for two months, with a load of 70% to 80% of one repetition maximum. Before and after strengthening, we evaluated (1) pelvis and hip excursions in the frontal and transverse planes during walking, (2) isokinetic hip passive external rotator torque, and (3) isokinetic concentric and eccentric peak torques of the hip external rotator muscles. Mixed analyses of variance (ANOVAs) were carried out for each dependent variable related to walking kinematics and isokinetic measurements (α = 0.05).

Results

The subgroup with smaller varus alignment, of the intervention group, presented a reduction in pelvic drop after strengthening (P = 0.03). The subgroup with larger varus alignment increased pelvic drop after strengthening, with a marginal significance (P = 0.06). The other kinematic excursions did not change (pelvic anterior rotation P = 0.30, hip internal rotation P = 0.54, and hip adduction P = 0.43). The intervention group showed increases in passive torque (P = 0.002), peak concentric torque (P < 0.001), and peak eccentric torque (P < 0.001), independently of FAC alignment. These results suggest that FAC varus alignment influences the effects of strengthening and should be considered when hip and trunk muscle strengthening is used to reduce pelvic drop during walking.

Hip muscle strength and protection against structural worsening and poor function and disability outcomes in knee osteoarthritis

OBJECTIVE

Examine associations of hip abductor strength with (1) cartilage damage worsening in the tibiofemoral and patellofemoral compartments 2 years later, and (2) poor function and disability outcomes 5 years later.

METHODS

Participants had knee osteoarthritis (K/L ≥ 2) in at least one knee. Hip abductor strength was measured using Biodex Dynamometry. Participants underwent 3.0T MRI of both knees at baseline and 2 years later. Baseline-to-2-year cartilage damage progression, defined as any worsening of WORMS cartilage damage score, was assessed at each tibiofemoral and patellofemoral surface. LLFDI (Late-Life Function and Disability Instrument) and Chair-Stand-Rate were recorded at baseline and 5-year follow-up; outcomes analyzed using quintiles. Poor outcomes were defined as remaining in the same low-function quintiles or being in a worse quintile at 5-year follow-up. We analyzed associations of baseline hip abductor strength with cartilage damage worsening and function and disability outcomes using multivariable log-binomial models.

RESULTS

275 knees from 164 persons [age = 63.7 (SD = 9.8) years, 79.3% women] comprised the structural outcome sample, and 187 persons [age = 64.2 (9.7), 78.6% women] the function and disability outcomes sample. Greater baseline hip abductor strength was associated with reduced risks of baseline-to-2-year medial patellofemoral and lateral tibiofemoral cartilage damage worsening [adjusted relative risks (RRs) range: 0.80-0.83) and with reduced risks of baseline-to-5-year poor outcomes for Chair-Stand-Rate and LLFDI Basic Lower-Extremity Function and Disability Limitation (adjusted RRs range: 0.91-0.94).

CONCLUSION

Findings support a beneficial role of hip abductor strength for disease modification and for function and disability outcomes, and as a potential therapeutic target in managing knee osteoarthritis.

Patients with early-stage knee osteoarthritis and knee pain have decreased hip abductor muscle strength while descending stairs

INTRODUCTION/OBJECTIVES

This study aimed to investigate the association between hip abductor muscle strength and knee pain in patients with early-stage knee osteoarthritis (OA) while ascending and descending stairs.

METHOD

This cross-sectional study included individuals with early-stage knee OA (Kellgren/Lawrence grades 1 or 2). Knee pain while ascending and descending stairs was evaluated using a knee OA-related health domain measure (Japanese Knee Osteoarthritis Measure). Knee extension and hip abductor muscle strength were also evaluated. The association between hip abductor muscle strength and knee pain while ascending and descending stairs was evaluated using multiple regression analysis.

RESULTS

A total of 157 participants were included in the final analysis. After the adjustment for age, sex, and knee extension strength, those with knee pain while descending stairs showed significantly decreased hip abductor muscle strength (β, - 0.09; 95% confidence interval [CI], - 0.19 to - 0.003). In contrast, after the adjustment for age, sex, and knee extension muscle strength, those with knee pain while ascending stairs did not have significantly decreased hip abductor muscle strength (β, - 0.06; 95% CI, - 0.15 to 0.02).

CONCLUSIONS

Patients with early-stage knee OA and knee pain while descending stairs had significantly reduced hip abductor muscle strength.

Exercise-induced hypoalgesia: A meta-analysis of exercise dosing for the treatment of chronic pain

OBJECTIVE

Increasing evidence purports exercise as a first-line therapeutic for the treatment of nearly all forms of chronic pain. However, knowledge of efficacious dosing respective to treatment modality and pain condition is virtually absent in the literature. The purpose of this analysis was to calculate the extent to which exercise treatment shows dose-dependent effects similar to what is seen with pharmacological treatments.

METHODS

A recently published comprehensive review of exercise and physical activity for chronic pain in adults was identified in May 2017. This report reviewed different physical activity and exercise interventions and their effectiveness in reducing pain severity and found overall modest effects of exercise in the treatment of pain. We analyzed this existing data set, focusing specifically on the dose of exercise intervention in these studies. We re-analyzed data from 75 studies looking at benefits of time of exercising per week, frequency of exercise per week, duration of intervention (in weeks), and estimated intensity of exercise.

RESULTS

Analysis revealed a significant positive correlation with exercise duration and analgesic effect on neck pain. Multiple linear regression modeling of these data predicted that increasing the frequency of exercise sessions per week is most likely to have a positive effect on chronic pain patients.

DISCUSSION

Modest effects were observed with one significant correlation between duration and pain effect for neck pain. Overall, these results provide insufficient evidence to conclude the presence of a strong dose effect of exercise in pain, but our modeling data provide tes predictions that can be used to design future studies to explicitly test the question of dose in specific patient populations.

Effects of exercise and physical activity promotion: meta-analysis informing the 2018 EULAR recommendations for physical activity in people with rheumatoid arthritis, spondyloarthritis and hip/knee osteoarthritis

Objective

To evaluate the effectiveness of exercise and physical activity (PA) promotion on cardiovascular fitness, muscle strength, flexibility, neuromotor performance (eg, balance) and daily PA in people with rheumatoid arthritis (RA), spondyloarthritis (SpA) and hip/knee osteoarthritis (HOA/KOA).

Methods

systematic review (SR) and meta-analysis (MA) were performed searching the databases PubMed/Medline, CENTRAL, Embase, Web of Science, Emcare and PsycInfo until April 2017. We included randomised controlled trials (RCTs) in adults (≥18 years) with RA, SpA and HOA/KOA, investigating the effects of exercise or PA promotion according to the public health PA recommendations by the American College of Sports Medicine. The time point of interest was the first assessment after the intervention period. If suitable, data were pooled in a MA using a random-effects model presented as standardised mean difference (SMD).

Results

The SR included 63 RCTs, of which 49 (3909 people with RA/SpA/HOA/KOA) were included in the MA. Moderate effects were found of aerobic exercises and resistance training on cardiovascular fitness (SMD 0.56 (95% CI 0.38 to 0.75)) and muscle strength (SMD 0.54 (95% CI 0.35 to 0.72)), respectively, but no effect of combined strength/aerobic/flexibility exercises on flexibility (SMD 0.12 (95% CI -0.16 to 0.41)). PA promotion interventions produced a small increase in PA behaviour (SMD 0.21 (95% CI 0.03 to 0.38)).

Conclusion

Exercises and PA promotion according to public health recommendations for PA improved cardiovascular fitness, muscle strength and PA behaviour, with moderate effect sizes in people with SpA, RA and HOA/KOA.

Trial registration number

CRD42017082131.

The TeMPO trial (treatment of meniscal tears in osteoarthritis): rationale and design features for a four arm randomized controlled clinical trial

BACKGROUND

Meniscal tears often accompany knee osteoarthritis, a disabling condition affecting 14 million individuals in the United States. While several randomized controlled trials have compared physical therapy to surgery for individuals with knee pain, meniscal tear, and osteoarthritic changes (determined via radiographs or magnetic resonance imaging), no trial has evaluated the efficacy of physical therapy alone in these subjects.

METHODS

The Treatment of Meniscal Tear in Osteoarthritis (TeMPO) Trial is a four-arm multi-center randomized controlled clinical trial designed to establish the comparative efficacy of two in-clinic physical therapy interventions (one focused on strengthening and one containing placebo) and two protocolized home exercise programs.

DISCUSSION

The goal of this paper is to present the rationale behind TeMPO and describe the study design and implementation strategies, focusing on methodologic and clinical challenges.

TRIAL REGISTRATION

The TeMPO Trial was first registered at clinicaltrials.gov with registration No. NCT03059004 . on February 14, 2017.

Quadriceps-strengthening exercise and quadriceps and knee biomechanics during walking in knee osteoarthritis: A two-centre randomized controlled trial

OBJECTIVE

To assess the effect of quadriceps strengthening on quadriceps muscle force, power, and work and tibio-femoral compressive loads during walking in adults with knee osteoarthritis.

METHODS

Study design: Two-center, randomized, controlled trial.

INTERVENTION

Patients with knee osteoarthritis were randomly allocated to quadriceps strengthening program (3 times weekly) or no attention control group.

MAIN OUTCOME MEASURES

Primary outcome was change from baseline in peak quadriceps force during walking at 12 weeks. Secondary outcomes included quadriceps power and work, knee compression forces during walking estimated with musculoskeletal modeling, muscle strength and pain and function. Outcomes were measured at baseline and 12 weeks.

RESULTS

30 patients were randomized to receive either training (n = 15) or no attention (n = 15). At follow-up, there were no statistical differences between groups for maximum quadriceps force, quadriceps positive power, negative work, and positive work, and knee compressive force. Maximum negative quadriceps power in early stance was statistically significantly increased 36% in the training group compared to the control group which was most likely partially a response to faster walking velocity at follow-up. Muscle strength and patient reported pain and function were improved in the training group compared to the control group.

CONCLUSIONS

Quadriceps strength training leads to increased muscle strength and improved symptomatic and functional outcomes but does not change quadriceps or knee joint biomechanics during walking. The biomechanical mechanism of improved health with strength training in knee osteoarthritis patients remains unknown. ClinicalTrials.gov Identifier: NCT01538407.

2018 EULAR recommendations for physical activity in people with inflammatory arthritis and osteoarthritis

Regular physical activity (PA) is increasingly promoted for people with rheumatic and musculoskeletal diseases as well as the general population. We evaluated if the public health recommendations for PA are applicable for people with inflammatory arthritis (iA; Rheumatoid Arthritis and Spondyloarthritis) and osteoarthritis (hip/knee OA) in order to develop evidence-based recommendations for advice and guidance on PA in clinical practice. The EULAR standardised operating procedures for the development of recommendations were followed. A task force (TF) (including rheumatologists, other medical specialists and physicians, health professionals, patient-representatives, methodologists) from 16 countries met twice. In the first TF meeting, 13 research questions to support a systematic literature review (SLR) were identified and defined. In the second meeting, the SLR evidence was presented and discussed before the recommendations, research agenda and education agenda were formulated. The TF developed and agreed on four overarching principles and 10 recommendations for PA in people with iA and OA. The mean level of agreement between the TF members ranged between 9.8 and 8.8. Given the evidence for its effectiveness, feasibility and safety, PA is advocated as integral part of standard care throughout the course of these diseases. Finally, the TF agreed on related research and education agendas. Evidence and expert opinion inform these recommendations to provide guidance in the development, conduct and evaluation of PA-interventions and promotion in people with iA and OA. It is advised that these recommendations should be implemented considering individual needs and national health systems.

The Influence of Exercise Dosing on Outcomes in Patients With Knee Disorders: A Systematic Review

Study Design Systematic review. Background Therapeutic exercise is commonly used to treat individuals with knee disorders, but dosing parameters for optimal outcomes are unclear. Large variations exist in exercise prescription, and research related to specific dosing variables for knee osteoarthritis, patellar tendinopathy, and patellofemoral pain is sparse. Objectives To identify specific doses of exercise related to improved outcomes of pain and function in individuals with common knee disorders, categorized by effect size. Methods Five electronic databases were searched for studies related to exercise and the 3 diagnoses. Means and standard deviations were used to calculate effect sizes for the exercise groups. The overall quality of evidence was assessed using the Physiotherapy Evidence Database scale. Results Five hundred eighty-three studies were found after the initial search, and 45 were included for analysis after screening. Physiotherapy Evidence Database scale scores were "fair" quality and ranged from 3 to 8. For knee osteoarthritis, 24 total therapeutic exercise sessions and 8- and 12-week durations of exercise were parameters most often associated with large effects. An exercise frequency of once per week was associated with no effect. No trends were seen with exercise dosing for patellar tendinopathy and patellofemoral pain. Conclusion This review suggests that there are clinically relevant exercise dosing variables that result in improved pain and function for patients with knee osteoarthritis, but optimal dosing is still unclear for patellar tendinopathy and patellofemoral pain. Prospective studies investigating dosing parameters are needed to confirm the results from this systematic review. Level of Evidence Therapy, level 1a. J Orthop Sports Phys Ther 2018;48(3):146-161. Epub 10 Jan 2018. doi:10.2519/jospt.2018.7637.

Identifying changes in gait waveforms following a strengthening intervention for women with knee osteoarthritis using principal components analysis

Lower limb strengthening exercise is pivotal for the management of symptoms related to knee osteoarthritis (OA). Though improvement in clinical symptoms is well documented, concurrent changes in gait biomechanics are ill-defined. This may occur because discrete analyses miss changes following an intervention, analyses limited to the knee undermine potential mechanical trade-offs at other joints, or strengthening interventions not been designed based on biomechanical principles. The purpose of this study was to characterize differences in entire gait waveforms for sagittal plane ankle, knee, and hip angles and external moments; the knee adduction moment; and frontal plane hip angle and moment following 12-weeks of a previously designed novel lower limb strengthening program. Forty women with knee OA completed two laboratory visits: one at baseline and one immediately following intervention (follow-up). Self-report measures, strength, and gait analyses were completed at each visit. Principal components analyses were completed for sagittal angles and external moments at the ankle, knee, and hip joints, as well as frontal plane angle and moment for the hip. Participants improved self-report and strength (p≤0.004). Two significant, yet subtle differences in principal components were identified between baseline and follow-up waveforms (p<0.05) pertaining to the knee and hip sagittal external moments. The subtle changes in concert with the lack of differences in other joints and planes suggest the lower limb strengthening program does not translate to changes in the gait waveform. It is likely this program is improving symptoms without worsening mechanics.

Impact of Physical Activity in Cardiovascular and Musculoskeletal Health: Can Motion Be Medicine?

Physical activity is a well-known therapeutic tool for various types of medical conditions, including vasculopathic diseases such as coronary artery disease, stroke, type 2 diabetes, and obesity. Additionally, increased physical activity has been proposed as a therapy to improve musculoskeletal health; however, there are conflicting reports about physical activity potentially leading to degenerative musculoskeletal disease, especially osteoarthritis (OA). Additionally, although physical activity is known to have its benefits, it is unclear as to what amount of physical activity is the most advantageous. Too much, as well as not enough exercise can have negative consequences. This could impact how physicians advise their patients about exercise intensity. Multiple studies have evaluated the effect of physical activity on various aspects of health. However, there is a paucity of systematic studies which review cardiovascular and musculoskeletal health as outcomes. Therefore, the purpose of this review was to assess how physical activity impacts these aspects of health. Specifically, we evaluated the effect of various levels of physical activity on: 1) cardiovascular and 2) musculoskeletal health. The review revealed that physical activity may decrease cardiovascular disease and improve OA symptoms, and therefore, motion can be considered a “medicine”. However, because heavy activity can potentially lead to increased OA risk, physicians should advise their patients that excessive activity can also potentially impact their health negatively, and should be done in moderation, until further study.

No effects of functional exercise therapy on walking biomechanics in patients with knee osteoarthritis: exploratory outcome analyses from a randomised trial

Aim

To assess the effects of a functional and individualised exercise programme on gait biomechanics during walking in people with knee OA.

Methods

Sixty participants were randomised to 12 weeks of facility-based functional and individualised neuromuscular exercise therapy (ET), 3 sessions per week supervised by trained physical therapists, or a no attention control group (CG). Three-dimensional gait analyses were used, from which a comprehensive list of conventional gait variables were extracted (totally 52 kinematic, kinetic and spatiotemporal variables). According to the protocol, the analyses were based on the ‘Per-Protocol’ population (defined as participants following the protocol with complete and valid gait analyses). Analysis of covariance adjusting for the level at baseline was used to determine differences between groups (95% CIs) in the changes from baseline at follow-up.

Results

The per-protocol population included 46 participants (24 ET/22 CG). There were no group differences in the analysed gait variables, except for a significant group difference in the second peak knee flexor moment and second peak vertical ground reaction force.

Conclusion

While plausible we have limited confidence in the findings due to multiple statistical tests and lack of biomechanical logics. Therefore we conclude that a 12-week supervised individualised neuromuscular exercise programme has no effects on gait biomechanics. Future studies should focus on exercise programmes specifically designed to alter gait patterns, or include other measures of mobility, such as walking on stairs or inclined surfaces.

Trial registration number

ClinicalTrials.gov: NCT01545258.

The role of muscle strengthening in exercise therapy for knee osteoarthritis: A systematic review and meta-regression analysis of randomized trials

OBJECTIVES

To analyze if exercise interventions for patients with knee osteoarthritis (OA) following the American College of Sports Medicine (ACSM) definition of muscle strength training differs from other types of exercise, and to analyze associations between changes in muscle strength, pain, and disability.

METHODS

A systematic search in 5 electronic databases was performed to identify randomized controlled trials comparing exercise interventions with no intervention in knee OA, and reporting changes in muscle strength and in pain or disability assessed as standardized mean differences (SMD) with 95% confidence intervals (95% CI). Interventions were categorized as ACSM interventions or not-ACSM interventions and compared using stratified random effects meta-analysis models. Associations between knee extensor strength gain and changes in pain/disability were assessed using meta-regression analyses.

RESULTS

The 45 eligible trials with 4699 participants and 56 comparisons (22 ACSM interventions) were included in this analysis. A statistically significant difference favoring the ACSM interventions with respect to knee extensor strength was found [SMD difference: 0.448 (95% CI: 0.091-0.805)]. No differences were observed regarding effects on pain and disability. The meta-regressions indicated that increases in knee extensor strength of 30-40% would be necessary for a likely concomitant beneficial effect on pain and disability, respectively.

CONCLUSION

Exercise interventions following the ACSM criteria for strength training provide superior outcomes in knee extensor strength but not in pain or disability. An increase of less than 30% in knee extensor strength is not likely to be clinically beneficial in terms of changes in pain and disability (PROSPERO: CRD42014015344).

Acupuncture for chronic pain and depression in primary care: a programme of research

Background

There has been an increase in the utilisation of acupuncture in recent years, yet the evidence base is insufficiently well established to be certain about its clinical effectiveness and cost-effectiveness. Addressing the questions related to the evidence base will reduce uncertainty and help policy- and decision-makers with regard to whether or not wider access is appropriate and provides value for money.

Aim

Our aim was to establish the most reliable evidence on the clinical effectiveness and cost-effectiveness of acupuncture for chronic pain by drawing on relevant evidence, including recent high-quality trials, and to develop fresh evidence on acupuncture for depression. To extend the evidence base we synthesised the results of published trials using robust systematic review methodology and conducted a randomised controlled trial (RCT) of acupuncture for depression.

Methods and results

We synthesised the evidence from high-quality trials of acupuncture for chronic pain, consisting of musculoskeletal pain related to the neck and low back, osteoarthritis of the knee, and headache and migraine, involving nearly 18,000 patients. In an individual patient data (IPD) pairwise meta-analysis, acupuncture was significantly better than both sham acupuncture (p < 0.001) and usual care (p < 0.001) for all conditions. Using network meta-analyses, we compared acupuncture with other physical therapies for osteoarthritis of the knee. In both an analysis of all available evidence and an analysis of a subset of better-quality trials, using aggregate-level data, we found acupuncture to be one of the more effective therapies. We developed new Bayesian methods for analysing multiple individual patient-level data sets to evaluate heterogeneous continuous outcomes. An accompanying cost-effectiveness analysis found transcutaneous electrical nerve stimulation (TENS) to be cost-effective for osteoarthritis at a threshold of £20,000 per quality-adjusted life-year when all trials were synthesised. When the analysis was restricted to trials of higher quality with adequate allocation concealment, acupuncture was cost-effective. In a RCT of acupuncture or counselling compared with usual care for depression, in which half the patients were also experiencing comorbid pain, we found acupuncture and counselling to be clinically effective and acupuncture to be cost-effective. For patients in whom acupuncture is inappropriate or unavailable, counselling is cost-effective.

Conclusion

We have provided the most robust evidence from high-quality trials on acupuncture for chronic pain. The synthesis of high-quality IPD found that acupuncture was more effective than both usual care and sham acupuncture. Acupuncture is one of the more clinically effective physical therapies for osteoarthritis and is also cost-effective if only high-quality trials are analysed. When all trials are analysed, TENS is cost-effective. Promising clinical and economic evidence on acupuncture for depression needs to be extended to other contexts and settings. For the conditions we have investigated, the drawing together of evidence on acupuncture from this programme of research has substantially reduced levels of uncertainty. We have identified directions for further research. Our research also provides a valuable basis for considering the potential role of acupuncture as a referral option in health care and enabling providers and policy-makers to make decisions based on robust sources of evidence.

Trial registration

Current Controlled Trials ISRCTN63787732.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

A three dimensional approach for quantifying resultant loading at the knee

BACKGROUND

Clinical effectiveness of lateral wedges for knee osteoarthritis is inconsistent across studies. One explanation is that knee loading is not fully described by the peak frontal-plane knee moment. The purpose of this study was to propose a 3D resultant approach to describing moments at the knee and evaluate how this moment changes in response to lateral wedges.

METHODS

Walking gait analysis was performed on 20 individuals with knee osteoarthritis, in their own shoes, with and without a six millimeter lateral wedge insole. Frontal-plane and 3D resultant moments were calculated for each participant and footwear condition. Paired t-tests identified differences between footwear conditions, correlations identified relationships between frontal-plane and 3D resultant moments, and regressions assessed relationships between moments and pain.

RESULTS

Significant reductions to peak frontal-plane moments (p=0.001) and 3D resultant moments at the same time point (p=0.042) were observed with lateral wedges. While an overall significant correlation was observed between change in frontal-plane moments and change in 3D resultant moments with a lateral wedge (r=0.68, p=0.001), 5/20 participants experienced disparate results where the frontal-plane moment was reduced yet the 3D moment increased.

CONCLUSIONS

While lateral wedges alter frontal-plane moment magnitude, the direction of change does not always correspond to the direction of change observed in the 3D resultant moment. Thus resultant knee load may sometimes increase with lateral wedges.

CLINICAL RELEVANCE

Future prospective studies should evaluate if changes in 3D resultant moments, and thus total knee load, offer an explanation as to why some participants do not experience clinical benefit from lateral wedges.

Hip Strength Deficits in People With Symptomatic Knee Osteoarthritis: A Systematic Review With Meta-analysis

Study Design Systematic review with meta-analysis. Background A complete understanding of impairments associated with knee osteoarthritis would optimize exercise interventions for people with knee osteoarthritis. Our current understanding of hip strength deficits in this population is based on studies with conflicting findings and small samples. There is a need to systematically review and pool current evidence. Objectives To determine whether hip strength deficits exist in people with symptomatic knee osteoarthritis. Methods Electronic databases (MEDLINE, CINAHL, Embase, the Cochrane Library, and PsycINFO) were searched through February 2016. Studies comparing hip strength in people diagnosed with symptomatic knee osteoarthritis to healthy control participants were included in the review. A meta-analysis with random effects was applied to relevant data from included studies and a modified Grading of Recommendations Assessment, Development and Evaluation approach was used to evaluate the quality of evidence for each pooled analysis. Results Five studies were included in the review. Meta-analysis revealed moderate-quality evidence of weaker isometric and isokinetic hip abduction strength in people with knee osteoarthritis (moderate difference: 7% to 24% weaker) and very low-quality evidence of no difference in isometric hip adduction strength. There was very low- to moderate-quality evidence of weaker isokinetic hip strength in the remaining planes of motion (moderate to large differences: 14% to 55% weaker). Conclusion Significant hip strength deficits exist in people with knee osteoarthritis. Hip strength assessment should be considered in clinical practice and may assist with directing targeted management strategies. Level of Evidence Symptom prevalence, level 1a-. J Orthop Sports PhysTher 2016;46(8):629-639. Epub3 Jul 2016. doi:10.2519/jospt.2016.6618.

Wedged Insoles and Gait in Patients with Knee Osteoarthritis: A Biomechanical Review

The study of gait biomechanics in individuals with knee osteoarthritis has become widespread, especially in regards to the knee adduction moment-a variable commonly believed to be associated with knee osteoarthritis progression. Unfortunately, this variable is often studied clinically without considering how it is derived, or what it means in a mechanical context. The use of footwear for knee osteoarthritis management has received much attention as well. However, in many cases, footwear is studied without regard for the mechanical effects they actually induce on the patient. Therefore, this review aims to summarize the current state of knowledge in regards to knee osteoarthritis gait and footwear biomechanics, by taking a step back to review the foundations of these two research areas. First, an overview of the calculation of the knee adduction moment is provided, along with mechanical considerations. Then, this is used to discuss current evidence for wedged insoles and highlight knowledge gaps. The intent was to place this mechanical information in a clinically-oriented framework for approachability by scientists, engineers and clinicians alike. Based on this discussion, areas for future investigation are proposed.

Knee joint contact mechanics during downhill gait and its relationship with varus/valgus motion and muscle strength in patients with knee osteoarthritis

OBJECTIVE

The objective of this exploratory study was to evaluate tibiofemoral joint contact point excursions and velocities during downhill gait and assess the relationship between tibiofemoral joint contact mechanics with frontal-plane knee joint motion and lower extremity muscle weakness in patients with knee osteoarthritis (OA).

METHODS

Dynamic stereo X-ray was used to quantify tibiofemoral joint contact mechanics and frontal-plane motion during the loading response phase of downhill gait in 11 patients with knee OA and 11 control volunteers. Quantitative testing of the quadriceps and the hip abductor muscles was also performed.

RESULTS

Patients with knee OA demonstrated larger medial/lateral joint contact point excursions (p < 0.02) and greater heel-strike joint contact point velocities (p < 0.05) for the medial and lateral compartments compared to the control group. The peak medial/lateral joint contact point velocity of the medial compartment was also greater for patients with knee OA compared to their control counterparts (p = 0.02). Additionally, patients with knee OA demonstrated significantly increased frontal-plane varus motion excursions (p < 0.01) and greater quadriceps and hip abductor muscle weakness (p = 0.03). In general, increased joint contact point excursions and velocities in patients with knee OA were linearly associated with greater frontal-plane varus motion excursions (p < 0.04) but not with quadriceps or hip abductor strength.

CONCLUSION

Altered contact mechanics in patients with knee OA may be related to compromised frontal-plane joint stability but not with deficits in muscle strength.

The effectiveness of an exercise programme on knee loading, muscle co-contraction, and pain in patients with medial knee osteoarthritis: A pilot study

BACKGROUND

Osteoarthritis (OA), which increases knee loading, muscle co-contraction, and pain, is a mechanical disease that requires biomechanical exploration to reduce pain in the knee. Therefore, this article aims to investigate the effectiveness of an exercise programme on the aforementioned outcomes in people with medial knee OA.

METHODS

Cohort pilot study design. A total of 19 patients with knee OA attended a six-week group exercise programme integrated with self-management education. The following outcomes were assessed before and after the exercise programme: external knee adduction moment (EKAM), knee adduction angular impulse (KAAI), knee antagonist muscle co-contraction, and pain subscale of the knee injury and osteoarthritis outcome score (KOOS).

RESULTS

Of the 19 patients, 14 completed the study. The EKAM and KAAI did not show statistical significance post-exercise intervention (p=0.21-0.7 and 0.56, respectively). Muscle co-contraction between vastus lateralis and biceps femoris muscles decreased in early-stance (64.78 (44.35) compared with 38.10 (23.10), p=0.01) and mid-stance (27.62 (32.12) compared with 14.94 (17.40), p=0.04). A corresponding significant pain reduction was observed (p=0.00) with a median (range) of 51.50 (47.00 to 62.50) at week 6 compared with 34.50 (29.25 to 41.25) at baseline.

CONCLUSION

This is the first known study to explore the effect of an exercise programme on knee loading and muscle co-contraction in patients with OA. Although the value of EKAM did not change, the findings suggest that the reduction in vastus lateralis and biceps femoris co-contraction might be the mechanism behind the reduction of pain.

High-intensity versus low-intensity physical activity or exercise in people with hip or knee osteoarthritis

BACKGROUND

Exercise or physical activity is recommended for improving pain and functional status in people with knee or hip osteoarthritis. These are complex interventions whose effectiveness depends on one or more components that are often poorly identified. It has been suggested that health benefits may be greater with high-intensity rather than low-intensity exercise or physical activity.

OBJECTIVES

To determine the benefits and harms of high- versus low-intensity physical activity or exercise programs in people with hip or knee osteoarthritis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; issue 06, 2014), MEDLINE (194 8 to June 2014) , EMBASE (198 0 to June 2014), CINAHL (1982 to June 2014), PEDro (1929 to June 2014), SCOPUS (to June 2014) and the World Health Organization (WHO) International Clinical Registry Platform (to June 2014) for articles, without a language restriction. We also handsearched relevant conference proceedings, trials, and reference lists and contacted researchers and experts in the field to identify additional studies.

SELECTION CRITERIA

We included randomized controlled trials of people with knee or hip osteoarthritis that compared high- versus low-intensity physical activity or exercise programs between the experimental and control group.High-intensity physical activity or exercise programs training had to refer to an increase in the overall amount of training time (frequency, duration, number of sessions) or the amount of work (strength, number of repetitions) or effort/energy expenditure (exertion, heart rate, effort).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and extracted data on trial details. We contacted authors for additional information if necessary. We assessed the quality of the body of evidence for these outcomes using the GRADE approach.

MAIN RESULTS

We included reports for six studies of 656 participants that compared high- and low-intensity exercise programs; five studies exclusively recruited people with symptomatic knee osteoarthritis (620 participants), and one study exclusively recruited people with hip or knee osteoarthritis (36 participants). The majority of the participants were females (70%). No studies evaluated physical activity programs. We found the overall quality of evidence to be low to very low due to concerns about study limitations and imprecision (small number of studies, large confidence intervals) for the major outcomes using the GRADE approach. Most of the studies had an unclear or high risk of bias for several domains, and we judged five of the six studies to be at high risk for performance, detection, and attrition bias.Low-quality evidence indicated reduced pain on a 20-point Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain scale (mean difference (MD) -0.84, 95% confidence interval (CI) -1.63 to -0.04; 4% absolute reduction, 95% CI -8% to 0%; number needed to treat for an additional beneficial outcome (NNTB) 11, 95% CI 14 to 22) and improved physical function on the 68-point WOMAC disability subscale (MD -2.65, 95% CI -5.29 to -0.01; 4% absolute reduction; NNTB 10, 95% CI 8 to 13) immediately at the end of the exercise programs (from 8 to 24 weeks). However, these results are unlikely to be of clinical importance. These small improvements did not continue at longer-term follow-up (up to 40 weeks after the end of the intervention). We are uncertain of the effect on quality of life, as only one study reported this outcome (0 to 200 scale; MD 4.3, 95% CI -6.5 to 15.2; 2% absolute reduction; very low level of evidence).Our subgroup analyses provided uncertain evidence as to whether increased exercise time (duration, number of sessions) and level of resistance (strength or effort) have an impact on the exercise program effects.Three studies reported withdrawals due to adverse events. The number of dropouts was small. Only one study systematically monitored adverse effects, but four studies reported some adverse effects related to knee pain associated with an exercise program. We are uncertain as to whether high intensity increases the number of adverse effects (Peto odds ratio 1.72, 95% CI 0.51 to 5.81; - 2% absolute risk reduction; very low level of evidence). None of the included studies reported serious adverse events.

AUTHORS' CONCLUSIONS

We found very low-quality to low-quality evidence for no important clinical benefit of high-intensity compared to low-intensity exercise programs in improving pain and physical function in the short term. There was insufficient evidence to determine the effect of different types of intensity of exercise programs.We are uncertain as to whether higher-intensity exercise programs may induce more harmful effects than those of lower intensity; this must be evaluated by further studies. Withdrawals due to adverse events were poorly monitored and not reported systematically in each group. We downgraded the evidence to low or very low because of the risk of bias, inconsistency, and imprecision.The small number of studies comparing high- and low-intensity exercise programs in osteoarthritis underscores the need for more studies investigating the dose-response relationship in exercise programs. In particular, further studies are needed to establish the minimal intensity of exercise programs needed for clinical effect and the highest intensity patients can tolerate. Larger studies should comply with the Consolidated Standards of Reporting Trials (CONSORT) checklist and systematically report harms data to evaluate the potential impact of highest intensities of exercise programs in people with joint damage.

The effects of resistance exercise in patients with knee osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

To analyze the effectiveness of resistance exercise in the treatment of knee osteoarthritis on pain, stiffness, and physical function.

DESIGN

Systematic review and meta-analysis of randomized controlled trials.

DATA SOURCES

PubMed, Embase, Cochrane Central Register of Controlled Trials, the Web of Science, and Chinese Biomedical Literature Database were searched from the date of inception to August 2015.

METHODS

Trials comparing effects of resistance exercise intervention with either non-intervention or psycho-educational intervention were selected by two reviewers independently. The risk of bias was assessed and studies with similar outcomes were pooled using a fixed or random effects model.

RESULTS

Data from 17 randomized clinical trials including 1705 patients were integrated. The main source of methodological bias in the selected studies was lack of double blinding. The meta-analysis results suggested that resistance exercise training relieved pain (standard mean difference [SMD]: -0.43; 95% confidence interval [CI]: -0.57 to -0.29; P < 0.001), alleviated stiffness (SMD: -0.31; 95%: CI -0.56 to -0.05; P = 0.02), and improved physical function (SMD -0.53; 95% CI: -0.70 to -0.37; P < 0.001).

CONCLUSION

Resistance exercise is beneficial in terms of reducing pain, alleviating stiffness, and improving physical function in patients with knee osteoarthritis.

Exercise for osteoarthritis of the knee: a Cochrane systematic review

OBJECTIVE

To determine whether land-based therapeutic exercise is beneficial for people with knee osteoarthritis (OA) in terms of reduced joint pain or improved physical function and quality of life.

METHODS

Five electronic databases were searched, up until May 2013. Randomised clinical trials comparing some form of land-based therapeutic exercise with a non-exercise control were selected. Three teams of two review authors independently extracted data and assessed risk of bias for each study. Standardised mean differences immediately after treatment and 2-6 months after cessation of formal treatment were separately pooled using a random effects model.

RESULTS

In total, 54 studies were identified. Overall, 19 (35%) studies reported adequate random sequence generation, allocation concealment and adequately accounted for incomplete outcome data. However, research results may be vulnerable to selection, attrition and detection bias. Pooled results from 44 trials indicated that exercise significantly reduced pain (12 points/100; 95% CI 10 to 15) and improved physical function (10 points/100; 95% CI 8 to 13) to a moderate degree immediately after treatment, while evidence from 13 studies revealed that exercise significantly improved quality of life immediately after treatment with small effect (4 points/100; 95% CI 2 to 5). In addition, 12 studies provided 2-month to 6-month post-treatment sustainability data which showed significantly reduced knee pain (6 points/100; 95% CI 3 to 9) and 10 studies which showed improved physical function (3 points/100; 95% CI 1 to 5).

CONCLUSIONS

Among people with knee osteoarthritis, land-based therapeutic exercise provides short-term benefit that is sustained for at least 2-6 months after cessation of formal treatment.

A Yoga Strengthening Program Designed to Minimize the Knee Adduction Moment for Women with Knee Osteoarthritis: A Proof-Of-Principle Cohort Study

People with knee osteoarthritis may benefit from exercise prescriptions that minimize knee loads in the frontal plane. The primary objective of this study was to determine whether a novel 12-week strengthening program designed to minimize exposure to the knee adduction moment (KAM) could improve symptoms and knee strength in women with symptomatic knee osteoarthritis. A secondary objective was to determine whether the program could improve mobility and fitness, and decrease peak KAM during gait. The tertiary objective was to evaluate the biomechanical characteristics of this yoga program. In particular, we compared the peak KAM during gait with that during yoga postures at baseline. We also compared lower limb normalized mean electromyography (EMG) amplitudes during yoga postures between baseline and follow-up. Primary measures included self-reported pain and physical function (Knee injury and Osteoarthritis Outcome Score) and knee strength (extensor and flexor torques). Secondary measures included mobility (six-minute walk, 30-second chair stand, stair climbing), fitness (submaximal cycle ergometer test), and clinical gait analysis using motion capture synchronized with electromyography and force measurement. Also, KAM and normalized mean EMG amplitudes were collected during yoga postures. Forty-five women over age 50 with symptomatic knee osteoarthritis, consistent with the American College of Rheumatology criteria, enrolled in our 12-week (3 sessions per week) program. Data from 38 were analyzed (six drop-outs; one lost to co-intervention). Participants experienced reduced pain (mean improvement 10.1–20.1 normalized to 100; p<0.001), increased knee extensor strength (mean improvement 0.01 Nm/kg; p = 0.004), and increased flexor strength (mean improvement 0.01 Nm/kg; p = 0.001) at follow-up compared to baseline. Participants improved mobility on the six-minute walk (mean improvement 37.7 m; p<0.001) and 30-second chair stand (mean improvement 1.3; p = 0.006) at follow-up compared to baseline. Fitness and peak KAM during gait were unchanged between baseline and follow-up. Average KAM during the yoga postures were lower than that of normal gait. Normalized mean EMG amplitudes during yoga postures were up to 31.0% of maximum but did not change between baseline and follow-up. In this cohort study, the yoga-based strengthening postures that elicit low KAMs improved knee symptoms and strength in women with knee OA following a 12 week program (3 sessions per week). The program also improved mobility, but did not improve fitness or reduce peak KAM during gait. The KAM during the yoga postures were lower than that of normal gait. Overall, the proposed program may be useful in improving pain, strength, and mobility in women with knee osteoarthritis. Clinical efficacy needs to be assessed using a randomized controlled trial design.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02146105.

Identifying potential working mechanisms behind the positive effects of exercise therapy on pain and function in osteoarthritis; a systematic review

OBJECTIVE

Although physical exercise is the commonly recommended for osteoarthritis (OA) patients, the working mechanism behind the positive effects of physical exercise on pain and function is a black box phenomenon. In the present study we aimed to identify possible mediators in the relation between physical exercise and improvements of pain and function in OA patients.

DESIGN

A systematic search for all studies evaluating the effects of physical exercise in OA patients and select those that additionally reported the change in any physiological factor from pre-to post-exercise.

RESULTS

In total, 94 studies evaluating 112 intervention groups were included. Most included studies evaluated subjects with solely knee OA (96 out of 112 groups). Based on the measured physiological factors within the included studies, 12 categories of possible mediators were formed. Muscle strength and ROM/flexibility were the most measured categories of possible mediators with 61 and 21 intervention groups measuring one or more physiological factors within these categories, respectively. 60% (31 out of 52) of the studies showed a significant increase in knee extensor muscle strength and 71% (22 out of 31) in knee flexor muscle strength over the intervention period. All 5 studies evaluating extension impairments and 10 out of 12 studies (83%) measuring proprioception found a significant change from pre-to post-intervention.

CONCLUSION

An increase of upper leg strength, a decrease of extension impairments and improvement in proprioception were identified as possible mediators in the positive association between physical exercise and OA symptoms.

The effect of exercise therapy on knee adduction moment in individuals with knee osteoarthritis: A systematic review

BACKGROUND

Exercise therapy is an evidence-based intervention for the conservative management of knee osteoarthritis. It is hypothesized that exercise therapy could reduce the knee adduction moment. A systematic review was performed in order to verify the effects of exercise therapy on the knee adduction moment in individuals with knee osteoarthritis in studies that also assessed pain and physical function.

METHODS

A comprehensive electronic search was performed on MEDLINE, Cochrane CENTRAL, EMBASE, Google scholar and OpenGrey. Inclusion criteria were randomized controlled trials with control or sham groups as comparator assessing pain, physical function, muscle strength and knee adduction moment during walking at self-selected speed in individuals with knee osteoarthritis that underwent a structured exercise therapy rehabilitation program. Two independent reviewers extracted the data and assessed risk of bias. For each study, knee adduction moment, pain and physical function outcomes were extracted. For each outcome, mean differences and 95% confidence intervals were calculated. Due to clinical heterogeneity among exercise therapy protocols, a descriptive analysis was chosen.

FINDINGS

Three studies, comprising 233 participants, were included. None of the studies showed significant differences between strengthening and control/sham groups in knee adduction moment. In regards to pain and physical function, the three studies demonstrated significant improvement in pain and two of them showed increased physical function following exercise therapy compared to controls. Muscle strength and torque significantly improved in all the three trials favoring the intervention group.

INTERPRETATION

Clinical benefits from exercise therapy were not associated with changes in the knee adduction moment. The lack of knee adduction moment reduction indicates that exercise therapy may not be protective in knee osteoarthritis from a joint loading point of view. Alterations in neuromuscular control, not captured by the knee adduction moment measurement, may contribute to alter dynamic joint loading following exercise therapy. To conclude, mechanisms other than the reduction in knee adduction moment might explain the clinical benefits of exercise therapy on knee osteoarthritis.