Effect of high-speed power training on muscle performance, function, and pain in older adults with knee osteoarthritis: A pilot investigation

The association between obesity, knee pain, and gait during stair descent in older adults with knee osteoarthritis

BACKGROUND

Obesity and knee osteoarthritis adversely affect activities of daily living in older adults. Together, the complexities of their interaction on mobility, including stair negotiation, are unresolved. The purpose of this study was to determine the relationship between obesity, pain, and stair negotiation in older adults with knee osteoarthritis.

METHODS

Older adults with symptomatic knee osteoarthritis and overweight or obesity participated in the study (n = 28; age range = 57.0-78.0 yrs.; body mass index range = 26.6-42.8 kg•m-2). The Western Ontario and McMaster Universities Osteoarthritis Index pain subscale was used to measure knee pain. Measurements included a three-dimensional biomechanical analysis during descent on a set of force plate-instrumented stairs and a timed stair descent test. Pearson's r was used to determine associations between body mass index and pain, stair descent weight-acceptance phase vertical ground reaction force (vGRF) variables and lower extremity joint kinematics and kinetics, and timed stair descent performance.

FINDINGS

Significant correlations existed between body mass index and pain (r = 0.41; p = 0.03), peak vGRF (r = 0.39; p = 0.04), vertical impulse (r = 0.49; p = 0.008), and peak ankle plantar flexor moments (r = 0.50; p = 0.007) in older adults with knee osteoarthritis.

INTERPRETATION

Greater obesity in older adults with knee osteoarthritis was associated with greater knee pain and higher ankle joint loads during stair descent. These results support the recommendations of osteoarthritis treatment guidelines for weight-loss as a first-line of treatment for older adults with obesity and knee osteoarthritis.

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 people with musculoskeletal pain differ from healthy cohorts in terms of global measures of strength? A systematic review and meta-analysis

OBJECTIVE

It is currently unknown if people with musculoskeletal pain display different multi-joint strength capacities than healthy cohorts. The aim was to investigate whether people with musculoskeletal pain show differences in global measures of strength in comparison to healthy cohorts.

DATA SOURCES

A systematic review was conducted using three databases (Medline, CINAHL and SPORTDiscus) and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

REVIEW METHODS

Studies involving participants with painful musculoskeletal conditions and multi-joint strength assessment measured at baseline were included. A meta-analysis was also performed to compute standardized mean differences (± 95% confidence intervals), using Hedge's g, and examined the differences in multi-joint strength at baseline between participants with painful musculoskeletal conditions and healthy participants.

RESULTS

In total, 5043 articles were identified, of which 20 articles met the inclusion criteria and were included in the qualitative analysis. The available evidence revealed that multi-joint strength values were limited to knee osteoarthritis, fibromyalgia, chronic low back pain, and rheumatoid arthritis. Only four studies were included in the quantitative synthesis and revealed that only small differences in both chest press (g = -0.34, 95% CI [-0.64, -0.03]) and leg press (g = -0.25, 95% CI [-0.49, -0.02]) existed between adult women with fibromyalgia and active community women.

CONCLUSION

There is a paucity of multi-joint strength values in participants with musculoskeletal pain. Quantitative comparison with healthy cohorts was limited, except for those with fibromyalgia. Adult women with fibromyalgia displayed reduced multi-joint strength values in comparison to active community women.

Effectiveness of Blood Flow Restriction on Functionality, Quality of Life and Pain in Patients with Neuromusculoskeletal Pathologies: A Systematic Review

BACKGROUND

Blood flow restriction is characterized as a method used during exercise at low loads of around 20-40% of a repetition maximum, or at a low-moderate intensity of aerobic exercise, in which cuffs that occlude the proximal part of the extremities can partially reduce arterial flow and fully restrict the venous flow of the musculature in order to achieve the same benefits as high-load exercise.

OBJECTIVE

The main objective of this systematic literature review was to analyze the effects of BFR intervention on pain, functionality, and quality of life in subjects with neuromusculoskeletal pathologies.

METHODS

The search to carry out was performed in PubMed, Cochrane, EMBASE, PEDro, CINHAL, SPORTDiscus, Trip Medical Database, and Scopus: "kaatsu" OR "ischemic training" OR "blood flow restriction" OR "occlusion resistance training" OR "vascular occlusion" OR "vascular restriction".

RESULTS

After identifying 486 papers and eliminating 175 of them due to duplication and 261 after reading the title and abstract, 50 papers were selected. Of all the selected articles, 28 were excluded for not presenting a score equal to or higher than 6 points on the PEDro scale and 8 for not analyzing the target outcome variables. Finally, 14 papers were selected for this systematic review.

CONCLUSIONS

The data collected indicate that the blood flow restriction tool is a therapeutic alternative due to its effectiveness under different exercise modalities. The benefits found include decreases in pain thresholds and improvement in the functionality and quality of life of the neuro-musculoskeletal patient during the first six weeks. However, the results provided by this tool are still not clear for medium- and long-term interventions.

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.

The preventive and therapeutic role of physical activity in knee osteoarthritis

The aim of this narrative review is to discuss the results of studies investigating the role of physical activity in knee osteoarthritis (OA). We also formulated two evidence-based exercise programs that could be prescribed to patients with symptomatic knee OA or after joint replacement. The PubMed and Google Scholar databases were searched for articles related to knee OA and physical activity. A total of 86 papers written in English and published from 1957 to 2021 were selected. Adapted physical activity, even at high intensity, does not appear to trigger or exacerbate knee OA; on the contrary, it may prevent obesity or lower limb muscle weakness, both of which are considered predisposing factors for the disease. In patients already diagnosed with knee OA, scientific evidence suggests that both land-based and aquatic activities combining aerobics, strength, and endurance programs are safe and effective. Physical interventions tailored to the patient may also accelerate recovery time after knee arthroplasty. Knee OA is a painful and disabling rheumatic disease that is very common in the elderly population. Pharmacotherapy has a modest effect in controlling disease progression, possibly due to the still limited understanding of OA pathogenesis. Non-pharmacologic interventions, including dietary and lifestyle changes and physical activity, may be more effective and safer than drugs in preventing or treating knee OA.

High-velocity resistance training as a tool to improve functional performance and muscle power in older adults

The aging process results in several physiological impairments that, in turn, may predispose older individuals to a series of restrictions on their functional capacity. These impairments are important to understand so that suitable conditions for healthier aging can be pursued. In this review, we first summarize the effects of aging on the neuromuscular system, as well as on the relation between the main age-associated physiological impairments and functional performance with an emphasis on muscle power output. We then proceed to discuss the effects of resistance training, specifically high-velocity resistance training (HVRT), on the aforementioned neuromuscular impairments, and on functional performance in healthy and mobility-limited older adults. Collectively, available evidence suggests that HVRT seems to be a safe and effective intervention for improving muscle power, functional performance, and mobility of older individuals. It also seems that mobility-limited older adults may improve power and functional performance to a greater extent than their healthy counterparts after HVRT, which is in line with the principle of diminishing returns. Considering that only a very limited number of investigations directly compared the effects of HVRT in more than one of the aforementioned groups, studies comparing the adaptations to HVRT of middle-aged adults and older adults with distinct functional capacities would be valuable to determine whether there are differences in neuromuscular adaptations, functional performance, and functional reserve among these groups.

Reduced knee extensor torque production at low to moderate velocities in postmenopausal women with knee osteoarthritis

This study aimed to determine deficits in knee extensor muscle function through the torque-time and torque-velocity relationships and whether these deficits are associated with reduced functional performance in postmenopausal women with knee osteoarthritis (KOA). A clinical sample of postmenopausal women with established KOA (n = 18, ≥55 years) was compared to an age-matched healthy control sample (CON) (n = 26). The deficits in different parameters of the knee extensor torque-time (maximal isometric torque and rate of torque development) and torque-velocity relationship (maximum muscle power, maximal velocity and torque at 0-500°·s^-1 ) were assessed through a protocol consisting of isometric, isotonic and isokinetic tests. Functional performance was evaluated with sit-to-stand and stair-climbing tasks using a sensor-based technology (ie, time- and power-based outcomes). Postmenopausal women with KOA showed reduced maximal isometric torque (Hedge's g effect size (g) = 1.05, p = 0.001) and rate of torque development (g = 0.77-1.17, all p ≤ 0.02), combined with impaired torque production at slow to moderate velocities (g = 0.92-1.70, p ≤ 0.004), but not at high or maximal velocities (g = 0.16, p > 0.05). KOA were slower (g = 0.81-0.92, p ≤ 0.011) and less powerful (g = 1.11-1.29, p ≤ 0.001) during functional tasks. Additionally, knee extensor deficits were moderately associated with power deficits in stair climbing (r = 0.492-0.659). To conclude, knee extensor muscle weakness was presented in postmenopausal women with KOA, not only as limited maximal and rapid torque development during isometric contractions, but also dynamically at low to moderate velocities. These deficits were related to impaired functional performance. The assessment of knee extensor muscle weakness through the torque-time and torque-velocity relationships might enable individual targets for tailored exercise interventions in KOA.

Muscle strength gains after strengthening exercise explained by reductions in serum inflammation in women with knee osteoarthritis

Background Individuals with knee osteoarthritis have elevated circulating inflammatory markers and altered cartilage properties but it is unclear if these features adapt to exercise. We aimed to determine (1) whether inflammatory markers, cartilage transverse relaxation time and thickness mediate the effect of body mass index (BMI) on quadriceps strength at baseline; and (2) whether these changes explain variance in quadriceps strength improvements after 12 weeks of exercise in women with knee osteoarthritis. Methods This secondary analysis (17 women with clinical knee osteoarthritis) of a randomized control trial compared supervised group interventions, 3 times/week for 12 weeks (36 sessions): (a) weight-bearing progressive resistive quadriceps exercise or (b) attention control. (1) From baseline, separate linear regressions were conducted with strength (Nm/kg) as the dependent, BMI as the predictor, and c-reactive protein, tumor necrosis factor, interleukin-6, cartilage transverse relaxation time or thickness as potential mediators. (2) Multiple linear regression analyses were completed with 12-week strength change (post-pre) as the dependent, change in serum inflammatory markers and cartilage measurements as predictors, and age, BMI and adherence as covariates. Findings (1) At baseline, there was no mediation. (2) A decrease in each of interleukin-6 (β = -0.104 (95% confidence intervals: -0.172, -0.036), R² = 0.51, P < 0.007) and tumor necrosis factor (β = -0.024 (-0.038, -0.009), R² = 0.54, P < 0.005) was associated with strength gains. Interpretation At baseline, inflammatory markers and cartilage measurements do not act as mediators of BMI on quadriceps strength. After 12 weeks of exercise, reduced interleukin-6 and tumor necrosis factor were associated with increased quadriceps strength in women with knee osteoarthritis.

Associations of the modified STarT back tool and Hospital Anxiety and Depression Scale (HADS) with gait speed and knee pain in knee osteoarthritis: a retrospective cohort study

OBJECTIVE

The association of the modified STarT Back Tool (mSBT) psychosocial measure with gait speed and knee pain in knee osteoarthritis is not well defined. This study aimed to, in patients with knee osteoarthritis, (i) examine the convergent validity of mSBT with the Hospital Anxiety and Depression Scale (HADS) and (ii) compare the predictive validity of mSBT and HADS with gait speed and knee pain.

METHODS

We performed a retrospective cohort analysis of mSBT, HADS, gait speed, and knee pain outcomes data collected from 119 patients who received outpatient physical therapy. Of these patients who were evaluated at their first (baseline) physical therapy visit, 55 had available data at the Week-16 follow-up visit.

RESULTS

mSBT and HADS showed moderately strong pairwise correlations (Spearman correlation > 0.57; p < 0.001). After adjusting for age, sex, body weight, and knee impairment variables in multivariable linear mixed-effects analyses, mSBT was associated with gait speed (p < 0.001) and knee pain intensity (p < 0.001) and it had comparable strength of association as HADS. In within-patient regression analyses, change in mSBT was associated with changes in gait speed (p = 0.04) and knee pain (p = 0.01) over 16 weeks.

CONCLUSION

The mSBT had convergent validity with HADS and it showed predictive validity with gait speed and knee pain in knee osteoarthritis. Although broader validation is required, the 5-item mSBT psychosocial measure may be applied as part of routine clinical care to assess psychological distress in patients with knee osteoarthritis. IMPLICATIONS FOR REHABILITATION The 5-item psychosocial subscale of the modified STarT Back tool (mSBT) showed good convergent validity with the 14-item Hospital Anxiety and Depression Scale in patients with knee osteoarthritis. The mSBT psychosocial subscale showed predictive validity, at both cross-sectional and longitudinal levels, with gait speed and knee pain in patients with knee osteoarthritis. The mSBT can potentially be used in the busy clinical setting to assess psychological distress in patients with knee osteoarthritis.

Relative Efficacy of Different Exercises for Pain, Function, Performance and Quality of Life in Knee and Hip Osteoarthritis: Systematic Review and Network Meta-Analysis

Background

Guidelines recommend exercise as a core treatment for osteoarthritis (OA). However, it is unclear which type of exercise is most effective, leading to inconsistency between different recommendations.

Objectives

The aim of this systematic review and network meta-analysis was to investigate the relative efficacy of different exercises (aerobic, mind–body, strengthening, flexibility/skill, or mixed) for improving pain, function, performance and quality of life (QoL) for knee and hip OA at, or nearest to, 8 weeks.

Methods

We searched nine electronic databases up until December 2017 for randomised controlled trials that compared exercise with usual care or with another exercise type. Bayesian network meta-analysis was used to estimate the relative effect size (ES) and corresponding 95% credibility interval (CrI) (PROSPERO registration: CRD42016033865).

Findings

We identified and analysed 103 trials (9134 participants). Aerobic exercise was most beneficial for pain (ES 1.11; 95% CrI 0.69, 1.54) and performance (1.05; 0.63, 1.48). Mind–body exercise, which had pain benefit equivalent to that of aerobic exercise (1.11; 0.63, 1.59), was the best for function (0.81; 0.27, 1.36). Strengthening and flexibility/skill exercises improved multiple outcomes at a moderate level. Mixed exercise was the least effective for all outcomes and had significantly less pain relief than aerobic and mind–body exercises. The trend was significant for pain (p = 0.01), but not for function (p = 0.07), performance (p = 0.06) or QoL (p = 0.65).

Conclusion

The effect of exercise varies according to the type of exercise and target outcome. Aerobic or mind–body exercise may be the best for pain and function improvements. Strengthening and flexibility/skill exercises may be used for multiple outcomes. Mixed exercise is the least effective and the reason for this merits further investigation.

Electronic supplementary material

The online version of this article (10.1007/s40279-019-01082-0) contains supplementary material, which is available to authorized users.

Muscular and Functional Capacity in Subjects Under Treatment for Knee Osteoarthritis: Role of Physical Activity Status

Background: The purpose of this study was to assess the role of physical activity (PA) in muscular and functional capacity in subjects under treatment for knee osteoarthritis submitted to an interdisciplinary educational program emphasizing the regular practice of PA and exercises. Methods: Subjects under treatment for primary knee osteoarthritis (N = 136; age = 66 [3]) were allocated in sedentary to sedentary (SED-SED, sedentary or insufficiently active at pre and post), active to sedentary (ACT-SED, active or very active at pre and sedentary or insufficiently active at post), sedentary to active (SED-ACT, sedentary or insufficiently active at pre and active or very active at post), and active to active (ACT-ACT, active or very active at pre and post) groups. Muscular capacity (isokinetic test), functional capacity (timed up and down stairs test, timed up and go test, and 5 times sit to stand test), and daily living PA (International PA Questionnaire short version) were assessed before and after (12 mo) the follow-up. Results: There were improvements in performance (P < .05) in the time to up and down stairs: 37% in SED-ACT and 27.5% in ACT-ACT; timed up and go test: 33.5% in SED-ACT, 19% in ACT-SED, and 40% in ACT-ACT; 5 times sit to stand test: 39% in SED-ACT and 51% in ACT-ACT groups after 12 months of follow-up. Conclusions: The present results suggest that high levels of daily living PA may have an important role in the prevention/management of knee osteoarthritis.

Force during functional exercises on land and in water in older adults with and without knee osteoarthritis: Implications for rehabilitation

BACKGROUND

Closed kinetic chain and plyometric exercises are commonly used in aquatic rehabilitation because they are believed to reduce joint loading whilst replicating functional tasks. However, the forces and relationship to land-based functional movement is unknown. This study aims to compare vertical ground reaction force during squats, calf raises and jumping in older adults with and without knee osteoarthritis on land and in water.

METHODS

Forty one participants (Healthy n = 21; Knee osteoarthritis n = 20; Age 68.5 (4.4) years) completed squats and calf raises at slow, medium and maximal speeds and jumping at maximal speed on land and in waist and chest depth water. Vertical ground reaction force and pain rating was measured in each environment.

RESULTS

Force in all exercises was significantly greater on land than in chest depth water (p < 0.005). Peak force was significantly greater at maximal speed compared to slow speed (p < 0.001). The pattern of force in squats at slow speed in water was different to on land, with force highest at the start and end of the exercise and decreasing in the central phase. Pain ratings were significantly lower (p < 0.001) in water compared to on land in squats.

CONCLUSIONS

Closed kinetic chain exercises offer inherently different loading in an aquatic environment. Body weight squats and calf raises in water could be defined as either neuromotor or low load, high velocity training. Maximal speed exercise in water produces higher relative load compared to slow speed and minimal pain providing an opportunity for clinicians to use greater speed to address power deficits.

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.

Beta-Alanine Does Not Enhance the Effects of Resistance Training in Older Adults

To investigate the potential of beta-alanine to increase muscular endurance of elder individuals in specific resistance-training protocols, we randomly assigned 27 participants (60-82 years of age) to a 12-week double-blind intervention using 3.2 g/day beta-alanine or placebo with or without resistance training to determine the effects on anthropometrics, muscular performance, and activities of daily living (ADL). The endurance-based resistance-training program (ERT) was given three times per week and included two sets of 15-25 repetitions on 11 computerized pneumatic machines (alternating upper and lower body) at an intensity of 50% of maximum lifting weight (1RM). Mixed design analysis of variance (ANOVA) revealed no significant group × time interactions (p > .05) for any anthropometric or strength measures except 1RM leg press (p = .010). A post hoc analysis revealed significant improvements in 1RM leg press for both the resistance-training groups (p < .001) but no significant between-group difference attributable to beta-alanine. For the 20-repetition chest and leg press tests, no main effects of beta-alanine or group × time interactions for the exercise versus control groups were observed. Pairwise comparisons, however, did reveal significant improvements in peak and average power for both tests and fatigue index for the chest press in resistance-training groups. Although beta-alanine had no effect on any measures, the ERT program did positively affect three performance variables: 1RM, mechanical power, and fatigue patterns during muscular endurance testing. Future research should examine beta-alanine with different dosages and training programs to expand upon our findings using endurance-based resistance training.

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.

Relative and absolute test-retest reliabilities of biomechanical risk factors for knee osteoarthritis progression: benchmarks for meaningful change

OBJECTIVE

Biomechanical factors are important treatment targets in knee osteoarthritis. The knee adduction (KAM) and flexion (KFM) moments, quadriceps strength and power, load frequency, and body mass index (BMI) all have the potential to affect knee articular cartilage integrity by modulating forces across the joint. To identify clinically meaningful change, however, these measurements must be reliable and sensitive to change. This study estimated relative and absolute test-retest reliabilities over long periods of biomechanical risk factors for knee osteoarthritis progression.

METHOD

Data from a longitudinal, observational study were analyzed for knee osteoarthritis patients with data at baseline, 6-month and 24-month follow-ups. Gait kinematics and kinetics, quadriceps strength and power, daily load frequency and BMI were collected. Relative and absolute test-retest reliabilities of these measures were estimated using intraclass correlation coefficients (ICCs) and standard errors of measurement (SEMs), respectively. Minimal detectable change at the 95% confidence level (MDC95) was also calculated.

RESULTS

Data from 46 participants [36 women; age 61.0 (6.6) years] were included. Good-to-excellent relative reliabilities (ICC ≥ 0.80) indicated that KAM peak and impulse, quadriceps strength and power, and BMI had a strong ability to discriminate amongst participants. Absolute reliabilities were high for quadriceps strength and BMI, which demonstrated reasonable within-participant variability (SEMs ≤ 11% of the mean). The MDC95 values supported use of clinical interventions effective in reducing BMI and KAM, and increasing quadriceps strength.

CONCLUSION

These data are useful in interpreting findings from interventional or longitudinal investigations by determining whether observed changes are beyond measurement error and interpretable as true change.

High-speed resistance training and balance training for people with knee osteoarthritis to reduce falls risk: study protocol for a pilot randomized controlled trial

BACKGROUND

The number of falls experienced by people with knee osteoarthritis (OA) is almost double the number experienced by people with no OA. The neuromuscular elements required to arrest a fall are more impaired in people with knee OA compared to their asymptomatic counterparts. Therefore, these elements may need to be incorporated into an exercise intervention to reduce the risk of falling. The aim of this study will be to examine the feasibility, safety and patient satisfaction of a high-speed resistance-training program, with and without balance exercises, in people with knee OA compared to a control group. The effect of these exercise programs on lower-limb muscle strength and physiological and functional risk factors for falls will also be examined.

METHODS

This study will be a pilot randomized controlled trial with a pre- and post-intervention design (outcome assessments at baseline and 8 weeks after participation commencement) comparing three groups: a control group (no intervention), a high-speed resistance-training group and a high-speed resistance-training plus balance exercises group. Thirty people with knee osteoarthritis aged 60-90 years will be recruited and randomized to one of the three groups. Feasibility and safety will be assessed by examining adherence to the exercise program, dropout rate, pain level during and following exercise, number of exercises stopped due to pain, and any adverse event or any incident that prevents the participant from completing the prescribed exercise. Secondary measures of lower-limb strength, physical function, self-reported pain and function, fear of falls, and executive function and quality of life will also be assessed. To determine statistical trends of effectiveness and hence to inform sample size for a fully powered study, analyses of the secondary outcomes will be performed to assess the changes within and between groups over time (pre-post) using repeated measure ANOVA.

DISCUSSION

The results of this study will improve understanding of what type of exercise is safe and beneficial for people with knee OA to reduce their risk of falling, and hence will inform the development of a future large research trial.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, ID: ACTRN12616001382460 . Registered on 6 October 2016.

Effects of High- and Low-Velocity Resistance Training on Gait Kinematics and Kinetics in Individuals with Hip Osteoarthritis: A Randomized Controlled Trial

OBJECTIVE

The aim of this study was to investigate the effects of high-velocity (HV) and low-velocity (LV) resistance training on gait kinematics and kinetics in patients with hip osteoarthritis.

DESIGN

This was a single-blind, randomized controlled trial. Forty-six women with hip osteoarthritis were randomly allocated to the HV (n = 23) or LV (n = 23) training group. The participants underwent an 8-week home-based the HV or LV resistance-training program, involving the hip and knee muscles. Outcome measures included gait kinematics and kinetics using 3-dimensional analyses, muscle strength and power, the Harris Hip Score, and hip pain using the visual analog scale.

RESULTS

There was no significant difference in changes for any of the outcome measures between groups. After the training session, muscle power, walking speed, and cadence significantly increased only in the HV group, whereas stride length and the peak hip extension angle during gait significantly increased, and pain on the visual analog scale and the peak ankle dorsiflexion moment during gait significantly decreased only in the LV group. Muscle strength and Harris Hip Score significantly increased in both groups.

CONCLUSIONS

The results of this study may indicate that the potential effect of resistance training on abnormal gait pattern depends on movement velocities during training.

Considerations of the Principles of Resistance Training in Exercise Studies for the Management of Knee Osteoarthritis: A Systematic Review

OBJECTIVE

To evaluate the methodologic quality of resistance training interventions for the management of knee osteoarthritis.

DATA SOURCES

A search of the literature for studies published up to August 10, 2015, was performed on MEDLINE (OVID platform), PubMed, Embase, and Physiotherapy Evidence Database databases. Search terms associated with osteoarthritis, knee, and muscle resistance exercise were used.

STUDY SELECTION

Studies were included in the review if they were published in the English language and met the following criteria: (1) muscle resistance training was the primary intervention; (2) randomized controlled trial design; (3) treatment arms included at least a muscle conditioning intervention and a nonexercise group; and (4) participants had osteoarthritis of the knee. Studies using preoperative (joint replacement) interventions with only postoperative outcomes were excluded. The search yielded 1574 results. The inclusion criteria were met by 34 studies.

DATA EXTRACTION

Two reviewers independently screened the articles for eligibility. Critical appraisal of the methodology was assessed according to the principles of resistance training and separately for the reporting of adherence using a specially designed scoring system. A rating for each article was assigned.

DATA SYNTHESIS

There were 34 studies that described a strength training focus of the intervention; however, the principles of resistance training were inconsistently applied and inadequately reported across all. Methods for adherence monitoring were incorporated into the design of 28 of the studies, but only 13 reported sufficient detail to estimate average dose of exercise.

CONCLUSIONS

These findings affect the interpretation of the efficacy of muscle resistance exercise in the management of knee osteoarthritis. Clinicians and health care professionals cannot be confident whether nonsignificant findings are because of the lack of efficacy of muscle resistance interventions, or occur through limitations in treatment prescription and patient adherence. Future research that seeks to evaluate the effects of muscle strength training interventions on symptoms of osteoarthritis should be properly designed and adherence diligently reported.

Effects of Multicomponent Exercise on Functional and Cognitive Parameters of Hypertensive Patients: A Quasi-Experimental Study

Purpose. The present study aimed to investigate the impact of a 6-month multicomponent exercise program (MCEP) on physical function and cognitive parameters of normotensive (NTS) and hypertensive (HTS) older patients and verify if age can influence the adaptations in response to the exercise. Methods. A total of 218 subjects, 101 NTS and 117 HTS, were recruited and underwent functional and cognitive evaluations before and after six months of a MCEP. The program of exercise was performed twice a week, for 26 weeks. The physical exercises were thought to mimic the activities of daily living and, therefore, aggregated functional and walking exercises. Exercise sessions were performed at moderate intensity. Results. Data indicated that HTS and NST patients showed a similar increase in the performance of walking speed test and one-leg stand test after the MCEP. Regarding age, results did not show differences in the magnitude of adaptations between old and young HTS and NTS patients. Conclusions. Data of the present study indicated that a 6-month MCEP was able to increase equally balance and mobility in NTS and HTS patients. Moreover, data demonstrated that aging did not seem to impair the capacity to adapt in response to exercise in both groups.

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).

The contribution of leg press and knee extension strength and power to physical function in people with knee osteoarthritis: A cross-sectional study

The purposes of this study were to 1) determine the additional contributions of leg press and knee extensor power, over and above that of strength, to the performance of physical function tasks in people with knee osteoarthritis, and 2) compare the ability of bilateral leg press to unilateral knee extensor strength and power to predict functional task performance.

METHODS

A cross-sectional, exploratory study of 40 individuals with tibiofemoral knee osteoarthritis resulting in moderate impairments in physical function was conducted. Physical function (Get-up and Go, timed stair climb and descent, and five time chair rise) and muscle performance (leg press and knee extension strength and power) were assessed.

RESULTS

After controlling for covariates and strength, leg press, but not knee extensor, power explained additional variance in physical function (11% and 21%). Conversely, adding strength to regression models including covariates and power did not consistently improve the prediction of physical function. Additionally, leg press power consistently explained more variance in physical function (44 to 57%) than involved (24 to 34%) or uninvolved (28 to 48%) knee extension power.

CONCLUSIONS

Leg press power may be a more functionally relevant measure of muscle performance than knee extension strength in this population. Future studies should investigate the effectiveness of interventions specifically designed to improve leg press power in people with knee osteoarthritis.

Rehabilitation Strategies for the Athletic Individual with Early Knee Osteoarthritis

Knee osteoarthritis (OA) is a major cause of disability in the United States. The condition has most commonly been associated with elderly sedentary individuals; however, it also can affect those who participate in regular athletic activities. The diagnosis and management of these individuals can be challenging because of both their higher level of physical activity and their overall athletic goals. Treatment requires an appropriate exercise regimen, rehabilitation program, and education of both the athlete and the coach. The focus of our article is to provide an up-to-date overview of the evaluation and management of the athletic individual who presents with symptomatic early knee OA, in particular, the nonsurgical rehabilitation treatment options available to the practitioner and the evidence to support these recommendations.

Muscle Power Is an Independent Determinant of Pain and Quality of Life in Knee Osteoarthritis

OBJECTIVE

This study examined the relationships between leg muscle strength, power, and perceived disease severity in subjects with knee osteoarthritis (OA) in order to determine whether dynamic leg extensor muscle power would be associated with pain and quality of life in knee OA.

METHODS

Baseline data on 190 subjects with knee OA (mean ± SD age 60.2 ± 10.4 years, body mass index 32.7 ± 7.2 kg/m(2) ) were obtained from a randomized controlled trial. Knee pain was measured using the Western Ontario and McMaster Universities Osteoarthritis Index, and health-related quality of life was assessed using the Short Form 36 (SF-36). One-repetition maximum (1RM) strength was assessed using the bilateral leg press, and peak muscle power was measured during 5 maximum voluntary velocity repetitions at 40% and 70% of 1RM.

RESULTS

In univariate analysis, greater muscle power was significantly associated with pain (r = -0.17, P < 0.02) and also significantly and positively associated with SF-36 physical component summary (PCS) scores (r = 0.16, P < 0.05). After adjustment for multiple covariates, muscle power was a significant independent predictor of pain (P ≤ 0.05) and PCS scores (P ≤ 0.04). However, muscle strength was not an independent determinant of pain or quality of life (P ≥ 0.06).

CONCLUSION

Muscle power is an independent determinant of pain and quality of life in knee OA. Compared to strength, muscle power may be a more clinically important measure of muscle function within this population. New trials to systematically examine the impact of muscle power training interventions on disease severity in knee OA are particularly warranted.

The associations between quadriceps muscle strength, power, and knee joint mechanics in knee osteoarthritis: A cross-sectional study

BACKGROUND

Abnormal knee joint mechanics have been implicated in the pathogenesis and progression of knee osteoarthritis. Deficits in muscle function (i.e., strength and power) may contribute to abnormal knee joint loading. The associations between quadriceps strength, power and knee joint mechanics remain unclear in knee osteoarthritis.

METHODS

Three-dimensional motion analysis was used to collect peak knee joint angles and moments during the first 50% of stance phase of gait in 33 participants with knee osteoarthritis. Quadriceps strength and power were assessed using a knee extension machine. Strength was quantified as the one repetition maximum. Power was quantified as the peak power produced at 40-90% of the one repetition maximum.

FINDINGS

Quadriceps strength accounted for 15% of the variance in peak knee flexion angle (P=0.016). Quadriceps power accounted for 20-29% of the variance in peak knee flexion angle (P<0.05). Quadriceps power at 90% of one repetition maximum accounted for 9% of the variance in peak knee adduction moment (P=0.05).

INTERPRETATION

These data suggest that quadriceps power explains more variance in knee flexion angle and knee adduction moment during gait in knee osteoarthritis than quadriceps strength. Additionally, quadriceps power at multiple loads is associated with knee joint mechanics and therefore should be assessed at a variety of loads. Taken together, these results indicate that quadriceps power may be a potential target for interventions aimed at changing knee joint mechanics in knee osteoarthritis.

Therapeutic modalities and postural balance of patients with knee osteoarthritis: systematic review

AbstractObjective The objective of this review was to evaluate the evidence of the influence of therapeutic modalities on postural balance in patients with knee osteoarthritis (OA).Methods A search for published papers on therapeutic modalities was conducted using the Pubmed, Medline, Lilacs and SciELO databases. The keywords “knee” and “balance” in combination with “osteoarthritis” were used as the search strategy. Randomized controlled clinical trials published in the last 10 years in either English or Portuguese were selected. The PEDro scale was applied to assess the quality of the selected clinical trials.Results A total of 46 studies of patients with knee OA were found, of which seven were analyzed in full and 39 were excluded because they did not meet the inclusion criteria. Of the seven studies reviewed, six were considered to have a high methodological quality on the PEDro scale. Several therapeutic modalities were found (physical exercise, hydrotherapy, electrotherapy and manual therapy), and postural balance improved in only three studies.Conclusion The studies included in this systematic review had a high methodological quality, so it can be concluded that the therapeutic modalities used in those studies improved postural balance in patients with knee OA.

Is long-term physical activity safe for older adults with knee pain?: a systematic review

OBJECTIVE

To determine whether long-term physical activity is safe for older adults with knee pain.

DESIGN

A comprehensive systematic review and narrative synthesis of existing literature was conducted using multiple electronic databases from inception until May 2013. Two reviewers independently screened, checked data extraction and carried out quality assessment. Inclusion criteria for study designs were randomised controlled trials (RCTs), prospective cohort studies or case control studies, which included adults of mean age over 45 years old with knee pain or osteoarthritis (OA), undertaking physical activity over at least 3 months and which measured a safety related outcome (adverse events, pain, physical functioning, structural OA imaging progression or progression to total knee replacement (TKR)).

RESULTS

Of the 8614 unique references identified, 49 studies were included in the review, comprising 48 RCTs and one case control study. RCTs varied in quality and included an array of low impact therapeutic exercise interventions of varying cardiovascular intensity. There was no evidence of serious adverse events, increases in pain, decreases in physical function, progression of structural OA on imaging or increased TKR at group level. The case control study concluded that increasing levels of regular physical activity was associated with lower risk of progression to TKR.

CONCLUSIONS

Long-term therapeutic exercise lasting 3 to 30 months is safe for most older adults with knee pain. This evidence supports current clinical guideline recommendations. However, most studies investigated selected, consenting older adults carrying out low impact therapeutic exercise which may affect result generalizability.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2014:CRD42014006913.

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.

Knee Extensor Power Relates to Mobility Performance in People With Knee Osteoarthritis: Cross-Sectional Analysis

BACKGROUND

Quadriceps femoris muscle strengthening is a common rehabilitation exercise for knee osteoarthritis (OA). More information is needed to determine whether targeting muscle power is a useful adjunct to strengthening for people with knee OA.

OBJECTIVE

The purpose of this study was to identify the predictive ability of knee extensor strength and knee extensor power in the performance of physical tasks in adults with knee OA.

DESIGN

This study used a cross-sectional design.

METHODS

Fifty-five participants with clinical knee OA were included (43 women; mean [SD] age=60.9 [6.9] years). Dependent variables were: timed stair ascent, timed stair descent, and the Six-Minute Walk Test (6MWT). Independent variables were: peak knee extensor strength and mean peak knee extensor power. Covariates were: age, body mass index, and self-efficacy. Multiple regression analyses were run for each dependent variable with just covariates, then a second model including strength, and then a third model including power. The R(2) values were compared between models.

RESULTS

Power explained greater variance than strength in all models. Over and above the covariates, power explained an additional 6% of the variance in the 6MWT, increasing the R(2) value from .33 to .39; 8% in the stair ascent test, increasing the R(2) value from .52 to .60; and 3% in the stair descent test, increasing the R(2) value from .44 to .47.

LIMITATIONS

The sample demonstrated very good mobility and muscle function scores and may not be indicative of those with severe knee OA.

CONCLUSIONS

In adults with knee OA, knee extensor power was a stronger determinant of walking and stair performance when compared with knee extensor strength. Clinicians should consider these results when advising patients on exercise to maintain or improve mobility.

A review of the relationship between leg power and selected chronic disease in older adults

OBJECTIVE

This review investigates the relationship between leg muscle power and the chronic conditions of osteoarthritis, diabetes mellitus, and cardiovascular disease among older adults. Current literature assessing the impact of chronic disease on leg power has not yet been comprehensively characterized. Importantly, individuals with these conditions have shown improved leg power with training.

METHODS

A search was performed using PubMed to identify original studies published in English from January 1998 to August 2013. Leg power studies, among older adults ≥ 50 years of age, which assessed associations with osteoarthritis, diabetes mellitus, and/or cardiovascular disease were selected. Studies concerning post-surgery rehabilitation, case studies, and articles that did not measure primary results were excluded.

RESULTS

Sixteen studies met inclusion criteria, addressing osteoarthritis (n=5), diabetes mellitus (n=5), and cardiovascular disease (n=6). Studies generally supported associations of lower leg power among older adults with chronic disease, although small sample sizes, cross-sectional data, homogenous populations, varied disease definitions, and inconsistent leg power methods limited conclusions.

CONCLUSIONS

Studies suggest that osteoarthritis, diabetes mellitus, and cardiovascular disease are associated with lower leg power compared to older adults without these conditions. These studies are limited, however, by the heterogeneity in study populations and a lack of standardized measurements of leg power. Future larger studies of more diverse older adults with well-defined chronic disease using standard measures of leg power and interventions to improve leg power in these older adults with chronic disease are needed.

Clinical strategies for addressing muscle weakness following knee injury

Muscle strength is a determinate of physical function and increasing muscle strength is an important clinical goal for patients with knee injury. This article discusses the emerging evidence regarding a novel rehabilitation strategy that uses disinhibitory modalities to increase neuromuscular activation in conjunction with traditional muscle strengthening for the purpose of maximizing strength gains following acute knee injury or surgery and in patients with knee osteoarthritis. The use of disinhibitory modalities and specific types of neuromuscular training for clinically maximizing strength are discussed.

Exercise for osteoarthritis of the knee

BACKGROUND

Knee osteoarthritis (OA) is a major public health issue because it causes chronic pain, reduces physical function and diminishes quality of life. Ageing of the population and increased global prevalence of obesity are anticipated to dramatically increase the prevalence of knee OA and its associated impairments. No cure for knee OA is known, but exercise therapy is among the dominant non-pharmacological interventions recommended by international guidelines.

OBJECTIVES

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

SEARCH METHODS

Five electronic databases were searched, up until May 2013.

SELECTION CRITERIA

All randomised controlled trials (RCTs) randomly assigning individuals and comparing groups treated with some form of land-based therapeutic exercise (as opposed to exercise conducted in the water) with a non-exercise group or a non-treatment control group.

DATA COLLECTION AND ANALYSIS

Three teams of two review authors independently extracted data, assessed risk of bias for each study and assessed the quality of the body of evidence for each outcome using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach. We conducted analyses on continuous outcomes (pain, physical function and quality of life) immediately after treatment and on dichotomous outcomes (proportion of study withdrawals) at the end of the study; we also conducted analyses on the sustained effects of exercise on pain and function (two to six months, and longer than six months).

MAIN RESULTS

In total, we extracted data from 54 studies. Overall, 19 (20%) studies reported adequate random sequence generation and allocation concealment and adequately accounted for incomplete outcome data; we considered these studies to have an overall low risk of bias. Studies were largely free from selection bias, but research results may be vulnerable to performance and detection bias, as only four of the RCTs reported blinding of participants to treatment allocation, and, although most RCTs reported blinded outcome assessment, pain, physical function and quality of life were participant self-reported.High-quality evidence from 44 trials (3537 participants) indicates that exercise reduced pain (standardised mean difference (SMD) -0.49, 95% confidence interval (CI) -0.39 to -0.59) immediately after treatment. Pain was estimated at 44 points on a 0 to 100-point scale (0 indicated no pain) in the control group; exercise reduced pain by an equivalent of 12 points (95% CI 10 to 15 points). Moderate-quality evidence from 44 trials (3913 participants) showed that exercise improved physical function (SMD -0.52, 95% CI -0.39 to -0.64) immediately after treatment. Physical function was estimated at 38 points on a 0 to 100-point scale (0 indicated no loss of physical function) in the control group; exercise improved physical function by an equivalent of 10 points (95% CI 8 to 13 points). High-quality evidence from 13 studies (1073 participants) revealed that exercise improved quality of life (SMD 0.28, 95% CI 0.15 to 0.40) immediately after treatment. Quality of life was estimated at 43 points on a 0 to 100-point scale (100 indicated best quality of life) in the control group; exercise improved quality of life by an equivalent of 4 points (95% CI 2 to 5 points).High-quality evidence from 45 studies (4607 participants) showed a comparable likelihood of withdrawal from exercise allocation (event rate 14%) compared with the control group (event rate 15%), and this difference was not significant: odds ratio (OR) 0.93 (95% CI 0.75 to 1.15). Eight studies reported adverse events, all of which were related to increased knee or low back pain attributed to the exercise intervention provided. No study reported a serious adverse event.In addition, 12 included studies provided two to six-month post-treatment sustainability data on 1468 participants for knee pain and on 1279 (10 studies) participants for physical function. These studies indicated sustainability of treatment effect for pain (SMD -0.24, 95% CI -0.35 to -0.14), with an equivalent reduction of 6 (3 to 9) points on 0 to 100-point scale, and of physical function (SMD -0.15 95% CI -0.26 to -0.04), with an equivalent improvement of 3 (1 to 5) points on 0 to 100-point scale.Marked variability was noted across included studies among participants recruited, symptom duration, exercise interventions assessed and important aspects of study methodology. Individually delivered programmes tended to result in greater reductions in pain and improvements in physical function, compared to class-based exercise programmes or home-based programmes; however between-study heterogeneity was marked within the individually provided treatment delivery subgroup.

AUTHORS' CONCLUSIONS

High-quality evidence indicates that land-based therapeutic exercise provides short-term benefit that is sustained for at least two to six months after cessation of formal treatment in terms of reduced knee pain, and moderate-quality evidence shows improvement in physical function among people with knee OA. The magnitude of the treatment effect would be considered moderate (immediate) to small (two to six months) but comparable with estimates reported for non-steroidal anti-inflammatory drugs. Confidence intervals around demonstrated pooled results for pain reduction and improvement in physical function do not exclude a minimal clinically important treatment effect. Since the participants in most trials were aware of their treatment, this may have contributed to their improvement. Despite the lack of blinding we did not downgrade the quality of evidence for risk of performance or detection bias. This reflects our belief that further research in this area is unlikely to change the findings of our review.

Physical therapies for improving balance and reducing falls risk in osteoarthritis of the knee: a systematic review

INTRODUCTION

osteoarthritis (OA) of knee has been reported as a risk factor for falls and reduced balance in the elderly. This systematic review evaluated the effectiveness of physical therapies in improving balance and reducing falls risk among patients with knee OA.

METHODS

a computerised search was performed to identify relevant studies up to November 2013. Two investigators identified eligible studies and extracted data independently. The quality of the included studies was assessed by the PeDro score.

RESULTS

a total of 15 randomised controlled trials involving 1482 patients were identified. The mean PeDro score was 7. The pooled standardised mean difference in balance outcome for strength training = 0.3346 (95% CI: 0.3207-0.60, P = 0.01 < 0.00001, P for heterogeneity = 0.85, I(2) = 0%). Tai Chi = 0.7597 (95% CI: 0.5130-1.2043, P<=0.0014, P for heterogeneity = 0.26, I(2) = 0%) and aerobic exercises = 0.6880 (95% CI: 0.5704-1.302, P < 0.00001, P for heterogeneity = 0.71, I(2) = 0%). While pooled results for falls risk outcomes in, strength training, Tai chi and aerobics also showed a significant reduction in reduced risk of falls significantly with pooled result 0.55 (95% CI: 0.41-0.68, P < 0.00001, P for heterogeneity = 0.39, I(2) = 6%).

CONCLUSION

strength training, Tai Chi and aerobics exercises improved balance and falls risk in older individuals with knee OA, while water-based exercises and light treatment did not significantly improve balance outcomes. Strength training, Tai Chi and aerobics exercises can therefore be recommended as falls prevention strategies for individuals with OA. However, a large randomised controlled study using actual falls outcomes is recommended to determine the appropriate dosage and to measure the potential benefits in falls reduction.

Knee osteoarthritis: Clinical connections to articular cartilage structure and function

Articular cartilage is a unique biphasic material that supports a lifetime of compressive and shear forces across joints. When articular cartilage deteriorates, whether due to injury, wear and tear or normal aging, osteoarthritis and resultant pain can ensue. Understanding the basic science of the structure and biomechanics of articular cartilage can help clinicians guide their patients to appropriate activity and loading choices. The purpose of this article is to examine how articular cartilage structure and mechanics, may interact with risk factors to contribute to OA and how this interaction provides guidelines for intervention choices This paper will review the microstructure of articular cartilage, its mechanical properties and link this information to clinical decision making.

Efficacy of rehabilitation programs for improving muscle strength in people with hip or knee osteoarthritis: a systematic review with meta-analysis

To analyse the effect of exercise-based rehabilitation programs for improving lower limb muscle strength in individuals with hip or knee osteoarthritis (OA). A systematic search utilizing seven databases identified randomized controlled trials (RCTs) evaluating lower limb strength outcomes of exercise-based interventions for participants with hip or knee OA. All studies were screened for eligibility and methodological quality. Quality of evidence was assessed using Grading of Recommendation, Assessment, Development and Evaluation (GRADE) approach. Data were pooled and meta-analyses performed where appropriate. Forty RCTs were included and the majority (77%) involved resistance based exercise programs. For knee OA populations, there was high quality evidence for improved knee extension (standardized mean difference (SMD) = 0.47, 95% confidence intervals (CI) 0.29, 0.66) and flexion strength (SMD = 0.74, 95% CI 0.56, 0.92) with low-intensity resistance program when compared to a control at short term (ST) follow-up. There was moderate quality evidence for a large effect favouring high-intensity resistance programs (SMD = 0.76, 95% CI 0.47, 1.06) when compared to a control. This effect was sustained at intermediate term (IT) follow-up (SMD = 0.80, 95% CI 0.44, 1.17). Few studies reported on outcomes at long term (LT) follow-up. Only one study reported on a population with hip OA. When compared to a control group, high-intensity resistance exercise demonstrated moderate quality of evidence for large and sustained improvements for knee muscle strength in knee OA patients. Further work is needed to compare different modes of exercise at a LT follow-up for knee OA patients and to address the dearth of literature evaluating exercise interventions in people with hip OA.

Knee power is an important parameter in understanding medial knee joint load in knee osteoarthritis

Objective

To determine the extent to which knee extensor strength and power explain variance in knee adduction moment (KAM) peak and impulse in clinical knee osteoarthritis (OA).

Methods

Fifty-three adults (mean ± SD age 61.6 ± 6.3 years, 11 men) with clinical knee OA participated. The KAM waveform was calculated from motion and force data and ensemble averaged from 5 walking trials. The KAM peak was normalized to body mass (Nm/kg). The mean KAM impulse reflected the mean total medial knee load during stride (Nm × seconds). For strength, the maximum knee extensor moment attained from maximal voluntary isometric contractions (MVIC) was normalized to body mass (Nm/kg). For power, the maximum knee extensor power during isotonic contractions, with the resistance set at 25% of MVIC, was normalized to body mass (W/kg). Covariates included age, sex, knee pain on the Knee Injury and Osteoarthritis Outcome Score, gait speed, and body mass index (BMI). Relationships of the KAM peak and impulse with strength and power were examined using sequential stepwise forward linear regressions.

Results

Covariates did not explain variance in the KAM peak. While extensor strength did not, peak knee extensor power explained 8% of the variance in the KAM peak (P = 0.02). Sex and BMI explained 24% of the variance in the KAM impulse (P < 0.05). Sex, BMI, and knee extensor power explained 31% of the variance in the KAM impulse (P = 0.02), with power contributing 7% (P < 0.05).

Conclusion

Knee extensor power was more important than isometric knee strength in understanding medial knee loads during gait.

Impact of exercise type and dose on pain and disability in knee osteoarthritis: a systematic review and meta-regression analysis of randomized controlled trials

OBJECTIVE

To identify the optimal exercise program, characterized by type and intensity of exercise, length of program, duration of individual supervised sessions, and number of sessions per week, for reducing pain and patient-reported disability in knee osteoarthritis (OA).

METHODS

A systematic review and meta-analysis of randomized controlled trials were performed. Standardized mean differences (SMDs) were combined using a random-effects model. Study-level covariates were applied in meta-regression analyses in order to reduce between-study heterogeneity.

RESULTS

Forty-eight trials were included. Similar effects in reducing pain were found for aerobic, resistance, and performance exercise (SMD 0.67, 0.62, and 0.48, respectively; P = 0.733). These single-type exercise programs were more efficacious than programs that included different exercise types (SMD 0.61 versus 0.16; P < 0.001). The effect of aerobic exercise on pain relief increased with an increased number of supervised sessions (slope 0.022 [95% confidence interval 0.002, 0.043]). More pain reduction occurred with quadriceps-specific exercise than with lower limb exercise (SMD 0.85 versus 0.39; P = 0.005) and when supervised exercise was performed at least 3 times a week (SMD 0.68 versus 0.41; P = 0.017). No impact of intensity, duration of individual sessions, or patient characteristics was found. Similar results were found for the effect on patient-reported disability.

CONCLUSION

Optimal exercise programs for knee OA should have one aim and focus on improving aerobic capacity, quadriceps muscle strength, or lower extremity performance. For best results, the program should be supervised and carried out 3 times a week. Such programs have a similar effect regardless of patient characteristics, including radiographic severity and baseline pain.

High-speed power training in older adults: a shift of the external resistance at which peak power is produced

Studies have shown that power training increases peak power (PP) in older adults. Evaluating the external resistance (% 1 repetition maximum [1RM]) at which PP is developed is critical given that changes in the components of PP (force and velocity) are dependent on the %1RM at which PP occurs. The purpose of this study was to compare the changes in PP (and the external resistance at which PP occurred) after 12 weeks of high-speed power training (HSPT) vs. traditional slow-speed strength training (SSST). Seventy-two older men and women were randomized to HSPT at 40% of the 1RM (HSPT: n = 24 [70.8 ± 6.8 years]); traditional resistance training at 80% 1RM (SSST: n = 22 [68.6 ± 7.8 years]); or control (CON: n = 18 [71.5 ± 6.1 years]). Measures of muscle performance were obtained at baseline and after the 12-week training intervention. Changes in muscle power and 1RM strength improved similarly with both HSPT and SSST, but HSPT shifted the external resistance at which PP was produced to a lower external resistance (from 67% 1RM to 52% 1RM) compared with SSST (from 65% 1RM to 62% 1RM) (p ≤ 0.05), thus increasing the velocity component of PP (change: HSPT = 0.18 ± 0.21 m·s; SSST = -0.03 ± 0.15 m·s) (p ≤ 0.05). Because sufficient speed of the lower limb is necessary for functional tasks related to safety (crossing a busy intersection, fall prevention), HSPT should be implemented in older adults to improve power at lower external resistances, thus increasing the velocity component of power and making older adults safer in their environment. These data provide clinicians with the necessary information to tailor exercise programs to the individual needs of the older adult, affecting the components of power.

Power training in patients with knee osteoarthritis: a pilot study on feasibility and efficacy

PURPOSE

To explore the feasibility and efficacy of using a power training exercise programme for the quadriceps femoris (QF) in elderly women with knee osteoarthritis (OA).

METHOD

A one-group quasi-experimental design with pre- and post-intervention measurements was conducted on 17 older adult women with knee OA pain. A bilateral QF exercise programme (24 sessions over 8 weeks) consisting of 3 series of 10 repetitions of flexion-extension as fast as possible at 40% of their one-repetition maximum (1RM) was performed in an outpatient physiotherapy clinic. The primary outcome measures were the knee function and associated problems using the Knee injury Osteoarthritis Outcome Score (KOOS) questionnaire and the weekly mean pain score from pain diaries using a visual analogue scale (VAS). QF strength (QFS), power (QFP) and work (QFW) were measured with an isokinetic dynamometer as secondary outcomes.

RESULTS

Significant improvements (p<0.05) were noted on the five categories of the KOOS. Significant decrease (p<0.01) was noted in pain intensity on VAS. QFP and QFW increased significantly on both sides (p<0.05). Exercise compliance was 99.5% for 16 participants.

CONCLUSIONS

A short power-training exercise programme is a feasible training modality for patients with knee OA, and significant functional improvements can be achieved. Further studies must be conducted to better understand the effects of the programme parameters and the generalizability of the findings.

The pain-relieving qualities of exercise in knee osteoarthritis

The purpose of this review article is to explore the role of therapeutic exercise in managing the pain associated with knee osteoarthritis (OA). Therapeutic exercise is often recommended as a first-line conservative treatment for knee OA, and current evidence supports exercise as an effective pain-relieving intervention. We explore the current state of evidence for exercise as a pain-relieving intervention for knee OA. Next, the mechanisms by which knee OA pain occurs and the potential ways in which exercise may act on those mechanisms are discussed. Clinical applicability and future research directions are suggested. Although evidence demonstrates that exercise reduces knee OA pain, optimal exercise mode and dosage have not been determined. In addition, it is not clearly understood whether exercise provides pain relief via peripheral or central mechanisms or a combination of both. Published clinical trials have explored a variety of interventions, but these interventions have not been specifically designed to target pain pathways. Current evidence strongly supports exercise as a pain-relieving option for those with knee OA. Future research needs to illuminate the mechanisms by which exercise reduces the pain associated with knee OA and the development of therapeutic exercise interventions to specifically target these mechanisms.

Efficacy of strength and aerobic exercise on patient-reported outcomes and structural changes in patients with knee osteoarthritis: study protocol for a randomized controlled trial

BACKGROUND

Despite an extensive literature on treatment interventions for patients with knee osteoarthritis, studies comparing the efficacy of different exercise interventions and living the life as usual on quality of life, cartilage quality and cost-effectiveness are lacking. The aim of the present study is to compare the efficacy of two different exercise programs compared to a control group in individuals with established radiographic and symptomatic knee osteoarthritis on self-reported knee-related quality of life, knee pain, physical function, and cartilage quality.

METHODS/DESIGN

A three-armed randomized controlled trial involving two exercise interventions and a control group of individuals doing as they usually do is described. The patients will have mild to moderate radiographic osteoarthritis according to the Kellgren and Lawrence classification (grade 2-3), and fulfill the American College of Rheumatology clinical criteria, be aged between 45 and 65 years, and have no other serious physical or mental illnesses. The patients will be randomly allocated to a strength exercise group; a cycling group, or a control group. The primary outcome is the Knee injury and Osteoarthritis Outcome Score knee-related quality of life subscale. Secondary outcomes include all five Knee Injury and Osteoarthritis Outcome Score subscales, morphological evaluation of cartilage including focal thickness, subchondral bone marrow edema, proteoglycan content and collagen degradation (measured using magnetic resonance imaging clinical sequences, T2 mapping and T1ρ), specific serum biomarkers, isokinetic muscle strength, maximal oxygen uptake, quality of life (EuroQol 5D), and self-efficacy (Arthritis Self-Efficacy Scale). A sample size calculation on the primary outcome showed that 207 individuals, 69 in each group, is needed to detect a clinically relevant difference of 10 points with 80% power and a significance level of 5%. Assessments will be conducted at baseline, 14 weeks, 1 year and 2 years post-randomization. The interventions will be a 14 weeks exercise program.

DISCUSSION

Although exercise therapy has been found to be effective in knee osteoarthritis, the knowledge of the underlying mechanisms for why exercise works is lacking. This study will contribute with knowledge on the efficacy of strength exercise versus cycling on patient-reported outcomes, cartilage quality and cost-effectiveness.

TRIAL REGISTRATION

Clinicaltrial.gov Identifier: NCT01682980.

Physical therapy management of knee osteoarthritis in the middle-aged athlete

Osteoarthritis (OA) is prevalent in today's population, including the athletic and recreationally active "middle-aged" population. OA is a degenerative condition of the articular/hyaline cartilage of synovial joints and commonly affects the knee joint. In general, athletic participation does not specifically influence a higher incidence of knee OA in this population; however, traumatic injury to the knee joint poses a definitive risk in developing early-onset OA. The purpose of this article is to review evidence-based nonpharmacological interventions for the conservative management of knee OA. Manual therapy, therapeutic exercise, patient education, and weight management are strongly supported in the literature for conservative treatment of knee OA. Modalities [thermal, electrical stimulation (ES), and low-level laser therapy (LLLT)] and orthotic intervention are moderately supported in the literature as indicated management strategies for knee OA. While many strongly supported conservative interventions have been published, additional research is needed to determine the most effective approach in treating knee OA.