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

Transcranial magnetic stimulation and electrical stimulation techniques used to measure the excitability of distinct neuronal populations that influence motor output in people with persistent musculoskeletal conditions: A scoping review and narrative synthesis of evidence

Functional impairments are evident in persistent musculoskeletal (MSK) conditions, and linked to altered excitability of neuronal elements contributing to motor output. In MSK conditions, transcranial magnetic stimulation (TMS) or electrical stimulation (ES) techniques have been used to investigate intracortical, corticospinal, spinal and neuromuscular excitability, which influence the efficacy of descending volley transmission to produce movement. This review compiled studies using TMS or ES to investigate neuronal excitability in persistent MSK conditions, to identify techniques used, and to synthesis evidence for neural deficits. We used narrative synthesis to summarise individual study findings. We included 60 studies; 52/60 used at least one TMS technique, and more frequently measured corticospinal tract excitability (48/52). 15/60 studies used at least one ES technique, and more frequently measured neuromuscular excitability (15/15). In tendinopathy, excitability was assessed for a range of distinct neurones; no study measured neuromuscular excitability in low back pain, osteoarthritis or shoulder pain, nor spinal or intracortical excitability in shoulder pain. This review identified a range of TMS and ES techniques used to assess excitability of neural elements. It provides insight for specific deficits contributing to functional impairments in certain persistent MSK conditions, while highlighting evidence gaps hindering the ability to draw meaningful inferences.

Artificial intelligence-based analysis of lower limb muscle mass and fatty degeneration in patients with knee osteoarthritis and its correlation with Knee Society Score

PURPOSE

Lower-limb muscle mass reduction and fatty degeneration develop in patients with knee osteoarthritis (KOA) and could affect their symptoms, satisfaction, expectation and functional activities. The Knee Society Scoring System (KSS) includes patient reported outcome measures, which is widely used to evaluate the status of knee function of KOA. This study aimed to clarify how muscle mass and fatty degeneration of the lower limb correlate with the KSS in patients with KOA.

METHODS

This study included 43 patients with end-stage KOA, including nine males and 34 females. Computed tomography (CT) images of the lower limb obtained for the planning of total knee arthroplasty were utilized. Ten muscle groups were segmented using our artificial-intelligence-based methods. Muscle volume was standardized by dividing by their height squared. The mean CT value for each muscle group was calculated as an index of fatty degeneration. Bivariate analysis between muscle volume or CT values and KSS was performed using Spearman's rank correlation test. Multiple regression analysis was performed, and statistical significance was set at p  < 0.05.

RESULTS

Bivariate analysis showed that the functional activity score was significantly correlated with the mean CT value of all muscle groups except the adductors and iliopsoas. Multiple regression analysis revealed that the functional activities score was significantly associated with the mean CT values of the gluteus medius and minimus muscles and the anterior and lateral compartments of the lower leg (β = 0.42, p = 0.01; β = 0.33, p = 0.038; and β = 0.37, p = 0.014, respectively).

CONCLUSION

Fatty degeneration, rather than muscle mass, in the lower-limb muscles was significantly associated with functional activities score of the KSS in patients with end-stage KOA. Notably, the gluteus medius and minimus and the anterior and lateral compartments of the lower leg are important muscles associated with functional activities.

Adapting Young Adults' In-Shoe Motion Sensor Gait Models for Knee Evaluation in Older Adults: A Study on Osteoarthritis and Healthy Knees

The human knee joint is crucial for mobility, especially in older adults who are susceptible to conditions like osteoarthritis (OA). Traditionally, assessing knee health requires complex gait analysis in clinical settings, which limits opportunities for convenient and continuous monitoring. This study leverages advancements in wearable technology to explore the adaptation of models based on in-shoe motion sensors (IMS), initially trained on young adults, for evaluating knee function in older populations, both healthy and with OA. Data were collected from 44 older OA patients, presenting various levels of severity, and 20 healthy older adults, with a focus on key knee indicators: knee angle measures (S1 to S3), temporal gait parameters (S4 and S5), and knee angular jerk cost metrics (S6 to S8). The models effectively identified trends and differences across these indicators between the healthy group and the OA group. Notably, in indicators S1, S2, S3, S7, and S8, the models exhibited a large effect size in correlation with true values. These findings suggest that gait models derived from younger, healthy individuals are possible to be robustly adapted for non-invasive, everyday monitoring of knee health in older adults, offering valuable insights for the early detection and management of knee impairments. However, limitations such as fixed biases due to differences in measurement systems and sensor placement inaccuracies were identified. Future research will aim to enhance model precision by addressing these limitations through domain adaptation techniques and improved sensor calibration.

Comparison of Maximum Isometric Strength of the Hip Joint Abductor and Knee Joint Extensor Muscles between Knee Osteoarthritis Patients with and without Self-reported Instability

Patients with knee osteoarthritis (KOA) often have impaired muscle function of the weight-bearing muscles, particularly in the knee and hip joints. This can lead to a significant loss of strength and power and may play a role in the perceived instability of the knee joint. The purpose of this study was to compare the maximum isometric strength of the hip abductor and knee extensor muscles between patients with KOA with and without perceived instability.Nineteen patients with KOA participated in this cross-sectional study and were divided into two groups. The first group (n = 10; women = 4, men = 6, mean age = 67.4 ± standard deviation [SD] 6.4 years) consisted of patients with self-reported instability in the knee joint, and the second group (n = 9; women = 5, men = 4, mean age = 69.6 ± SD 6.7 years) consisted of patients without self-reported instability. Functional and activity limitations were quantified using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Maximum isometric strength of the hip abductors and knee extensors was measured using a belt-mounted handheld dynamometer and expressed as torque (Newton meters [Nm]) by multiplication with the determined lever arm. Torque was normalized to body weight and height.Patients with instability (median WOMAC score = 68) achieved a significantly lower mean torque in hip abduction than the patients without instability (median WOMAC score = 39) (p = 0.01; Cohen's d = 1.31). There was no significant difference in knee extension torque between the groups (p = 0.202; Cohen's d = 0.58).KOA patients with instability were able to develop significantly lower hip abductor strength than those without instability, suggesting that targeted strength training of this muscle group may be important for this group of patients.

Hip Abductor Muscle Strength in Patients After Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Impaired hip abductor muscle strength indirectly leads to changes in knee kinematics and may cause pain or functional limitations after total knee arthroplasty (TKA). This study aimed to evaluate and quantify hip abductor muscle strength deficits after TKA and investigate external factors influencing hip abductor muscle strength after TKA.

METHODS

A comprehensive literature search was performed, and clinical studies reporting hip abductor muscle strength after primary TKA were included. We performed meta-analyses to assess the relative hip muscle strength of the operated leg compared to the contralateral limb and the change from preoperative to postoperative values across multiple time points. We also assessed the pooled absolute hip muscle strength across the following time points: preoperatively, up to two months, two to six months, and more than six months postoperatively. There were 15 studies involving 823 patients that met our inclusion criteria.

RESULTS

Compared with preoperative values, patients had a mean strength deficit of 18.0% (95% confidence interval (CI) [-30.8 to -5.2] at up to two months postoperatively, a non-significant deficit of 11.3% (CI [-32.7 to 10.2]) at two to six months postoperatively and an increase of 18.4% (CI [2.7 to 34.1]) at ≥ six months postoperatively. Compared with the contralateral side, patients had a mean abductor strength deficit of 11.5% (CI [-16.2 to -6.9]) preoperatively, 23.2% (CI [-27.6 to -18.8]) at up to two months postoperatively, a non-significant deficit of 10.8% (CI [-23.2 to 1.6]) at two to six months postoperatively and no difference (0.6% (CI [-4.2 to 5.4]) more than six months postoperatively. The study quality was low to moderate.

CONCLUSIONS

Hip abductor muscle strength is reduced preoperatively in patients undergoing TKA, continues to decrease in the immediate postoperative period, but fully recovers within six to 12 months. Although these data can be used to guide patient education and rehabilitation planning, they should be interpreted with caution due to the heterogeneous and limited high-quality evidence.

Estimating Indicators for Assessing Knee Motion Impairment During Gait Using In-Shoe Motion Sensors: A Feasibility Study

Knee joint function deterioration significantly impacts quality of life. This study developed estimation models for ten knee indicators using data from in-shoe motion sensors to assess knee movement during everyday activities. Sixty-six healthy young participants were involved, and multivariate linear regression was employed to construct the models. The results showed that eight out of ten models achieved a "fair" to "good" agreement based on intra-class correlation coefficients (ICCs), with three knee joint angle indicators reaching the "fair" agreement. One temporal indicator model displayed a "good" agreement, while another had a "fair" agreement. For the angular jerk cost indicators, three out of four attained a "fair" or "good" agreement. The model accuracy was generally acceptable, with the mean absolute error ranging from 0.54 to 0.75 times the standard deviation of the true values and errors less than 1% from the true mean values. The significant predictors included the sole-to-ground angles, particularly the foot posture angles in the sagittal and frontal planes. These findings support the feasibility of estimating knee function solely from foot motion data, offering potential for daily life monitoring and rehabilitation applications. However, discrepancies in the two models were influenced by the variance in the baseline knee flexion and sensor placement. Future work will test these models on older and osteoarthritis-affected individuals to evaluate their broader applicability, with prospects for user-tailored rehabilitation applications. This study is a step towards simplified, accessible knee health monitoring through wearable technology.

Navigating the Global Landscape of Exercise Interventions for Knee Osteoarthritis: Exploring Evolving Trends and Emerging Frontiers From a Bibliometric and Visualization Analysis Perspective (2011-2022)

OBJECTIVES

This study utilizes visual analysis methods to retrospectively examine the evolution and trends in exercise interventions for knee osteoarthritis (KOA) research from 2011 to 2022.

DESIGN

Bibliometric and visualization analysis review.

SETTING AND PARTICIPANTS

Using the Web of Science database, the literature search range is from January 1, 2011, to December 31, 2022, with the language specified as English and document type set to Article.

METHODS

Visual analysis was used to analyze literature in the field of exercise interventions for KOA, with KOA and exercise interventions as the key search terms. Visualization maps for countries/regions were created using Tableau and Scimago Graphica software. Institutional, author, and keyword visualization maps were drawn using CiteSpace and VOSviewer software.

RESULTS

In total, 3137 articles were included in the visual analysis. The United States emerged as the leading country in terms of publication volume and contribution. Moreover, developed countries such as the United States, Australia, United Kingdom, and Canada have established close and stable cooperative relationships. The University of Melbourne stood out as the institution with both the highest publication volume and centrality. At the forefront of research output in this field was Bennell K.L. from the University of Melbourne. The journal with the highest co-citation frequency was Osteoarthritis and Cartilage. The keyword clustering map highlighted an evolution in the field of exercise interventions for KOA, emphasizing 8 key research themes spanning knee osteoarthritis, serum cartilage, osteoarthritis initiative, patellofemoral pain, total knee arthroplasty, exercise-induced hypoalgesia, isometric exercise, and anterior cruciate ligament reconstruction. Burst analysis revealed that older adult was the earliest and most prominent keyword, with contemporary topics such as patellofemoral pain, safety, musculoskeletal disorder, and neuromuscular exercise considered as research hotspots and future directions in this field.

CONCLUSIONS AND IMPLICATIONS

The global attention on exercise interventions for KOA research is expanding, emphasizing the importance of strengthened connections among developing countries and collaborative author groups. Recent trends have shifted toward topics such as neuromuscular training, treatment safety, and musculoskeletal disorders, whereas research interest in patellofemoral pain remains unabated. Neuromuscular training for KOA represents the current frontier in this field. Future research should delve into the effects of diverse types of exercise interventions for KOA on neuromuscular injury and recovery, exploring feasibility and safety to formulate personalized exercise plans for patients with KOA.

Effectiveness of exercise on pain intensity and physical function in patients with knee and hip osteoarthritis: an umbrella and mapping review with meta-meta-analysis

PURPOSE

The aim of this review was to provide a qualitative and quantitative overview of the effects of exercise on pain, physical function, and quality of life for patients with knee and hip osteoarthritis.

MATERIALS AND METHODS

This study was an umbrella and mapping review with meta-meta-analysis. Meta-analyses of randomized controlled trials were included. The methodological quality and risk of bias were evaluated using the Modified Quality Assessment Scale for Systematic Reviews and the Risk of Bias in Systematic Reviews tool. The quality of evidence was evaluated using the Physical Activity Guidelines Advisory Committee Grading Criteria.

RESULTS

41 meta-analyses were included, 43.9% of the studies had adequate methodological quality, and 56.1% of the studies had a low risk of bias. Moderate evidence was found that exercise decreases pain intensity (33 meta-analyses; SMD = -0.49; 95% CI -0.56 to -0.42), improves function (19 meta-analyses; SMD = -0.50; 95% CI -0.58 to -0.41), strength (6 meta-analyses; SMD = -0.57; 95% CI -0.70 to -0.44) and quality of life (SMD = -0.36; 95% CI -0.46 to -0.27) for patients with hip and knee osteoarthritis.

CONCLUSION

Exercise is an effective intervention to decrease pain intensity and improve function in patients with hip and knee osteoarthritis.(PROSPERO, CRD42020221987).

Are the Effects of Resistance Exercise on Pain and Function in Knee and Hip Osteoarthritis Dependent on Exercise Volume, Duration, and Adherence? A Systematic Review and Meta-Analysis

OBJECTIVE

The purpose of this study was to determine dose parameters for resistance exercise associated with improvements in pain and physical function in knee and hip osteoarthritis (OA) and whether these improvements were related to adherence.

METHODS

We searched six databases, from inception to January 28, 2023, for randomized controlled trials comparing land-based, resistance exercise-only interventions with no intervention, or any other intervention. There were four subgroups of intervention duration: 0 to <3 months, 3 to 6 months, >6 to <12 months, ≥12 months. The between-group effect was calculated for immediate postintervention pain and physical function (activities of daily living [ADL] and sports/recreation [SPORT]).

RESULTS

For both knee and hip, data from 280 studies showed moderate benefit for pain, physical function ADL, and physical function SPORT in favor of interventions 3 to 6 months. For the knee, there was also a moderate benefit for physical function ADL in favor of interventions >6 to <12 months. From 151 knee and hip studies that provided total exercise volume data (frequency, time, duration), there was no association between volume with the effect size for pain and physical function. A total of 74 studies (69 knee, 5 hip) reported usable adherence data. There was no association between adherence with the effect size for pain and physical function.

CONCLUSION

In knee and hip OA, resistance exercise interventions 3 to 6 months (and for the knee >6 to <12 months) duration improve pain and physical function. Improvements do not depend on exercise volume or adherence, suggesting exercise does not require rigid adherence to a specific dose.

No sign of weakness: a systematic review and meta-analysis of hip and calf muscle strength after anterior cruciate ligament injury

OBJECTIVE

We aimed to determine hip and lower-leg muscle strength in people after ACL injury compared with an uninjured control group (between people) and the uninjured contralateral limb (between limbs).

DESIGN

Systematic review with meta-analysis.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, Scopus, Cochrane CENTRAL and SportDiscus to 28 February 2023.

ELIGIBILITY CRITERIA

Primary ACL injury with mean age 18-40 years at time of injury. Studies had to measure hip and/or lower-leg muscle strength quantitatively (eg, dynamometer) and report muscle strength for the ACL-injured limb compared with: (i) an uninjured control group and/or (ii) the uninjured contralateral limb. Risk of bias was assessed according to Cochrane Collaboration domains.

RESULTS

Twenty-eight studies were included (n=23 measured strength ≤12 months post-ACL reconstruction). Most examined hip abduction (16 studies), hip extension (12 studies) and hip external rotation (7 studies) strength. We found no meaningful difference in muscle strength between people or between limbs for hip abduction, extension, internal rotation, flexion or ankle plantarflexion, dorsiflexion (estimates ranged from -9% to +9% of comparator). The only non-zero differences identified were in hip adduction (24% stronger on ACL limb (95% CI 8% to 42%)) and hip external rotation strength (12% deficit on ACL limb (95% CI 6% to 18%)) compared with uninjured controls at follow-ups >12 months, however both results stemmed from only two studies. Certainty of evidence was very low for all outcomes and comparisons, and drawn primarily from the first year post-ACL reconstruction.

CONCLUSION

Our results do not show widespread or substantial muscle weakness of the hip and lower-leg muscles after ACL injury, contrasting deficits of 10%-20% commonly reported for knee extensors and flexors. As it is unclear if deficits in hip and lower-leg muscle strength resolve with appropriate rehabilitation or no postinjury or postoperative weakness occurs, individualised assessment should guide training of hip and lower-leg strength following ACL injury.

PROSPERO REGISTRATION NUMBER

CRD42020216793.

Arm swing asymmetry in people with Parkinson's disease and its relationship with gait: A systematic review and meta-analysis

BACKGROUND

Individuals with Parkinson's disease present arm swing alterations that can adversely affect their locomotion.

OBJECTIVE

To identify differences in arm swing asymmetry (ASA) between individuals with Parkinson's disease (PD) and healthy individuals and to investigate the relationship between ASA, temporal-spatial gait parameters, and disease progression.

METHODS

A literature search was conducted in PubMed, Scopus, ProQuest, Web of Science, and EBSCOhost up to February 2023. Cross-sectional studies evaluating parameters of arm swing (AS) and ASA were included. Methodological quality was assessed using the Critical Appraisal Checklist, and the quality of the evidence was measured with a modified Grading of Recommendations Assessment, Development, and Evaluation.

RESULTS

Fourteen studies were included in the systematic review (1130 participants). Irrespective of the medication phase (ON or OFF) and the type of walk test employed, the meta-analysis showed moderate-quality evidence that individuals with PD have increased ASA amplitude (SMD = 0.84; 95% CI: 0.69, 0.99; I²= 0%).Very low-quality evidence suggests higher ASA velocity (SMD=0.64; 95% CI: 0.24, 1.05; I²=59%) and lower AS amplitude on both the most affected (ES = -1.99, 95% CI: -3.04, -0.94, I2: 91%) and the least affected sides (ES = -0.75, 95% CI: -1.05, -0.44; I²=66%). Meta-regression indicated that ASA is inversely related to disease duration (Z: -2.4892, P< 0.05) and motor symptoms progression (Z: -2.1336, P< 0.05).

CONCLUSIONS

Regardless of the medication phase and the type of walk test employed, individuals with PD exhibited greater ASA and decreased AS amplitude than healthy individuals. ASA decreases as the disease progresses and symptoms worsen.

Hip Abductor Weakness and Its Association With New or Worsened Knee Pain: Data From the Multicenter Osteoarthritis Study

OBJECTIVE

Hip abductors, important for controlling pelvic and femoral orientation during gait, may affect knee pain. Our objective was to evaluate the relation of hip abductor strength to worsened or new-onset frequent knee pain. Given previously noted associations of knee extensor strength with osteoarthritis in women, we performed sex-specific analyses.

METHODS

We used data from the Multicenter Osteoarthritis study. Hip abductor and knee extensor strength was measured. Knee pain was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire and a question about frequent knee pain at baseline (144-month visit), and 8, 16, and 24 months thereafter. Knee pain outcomes were worsened knee pain (2-point increase in WOMAC pain) and incident frequent knee pain (answering yes to the frequent knee pain question among those without frequent knee pain at baseline). Leg-specific analyses tested hip abductor strength as a risk factor for worsened and new frequent knee pain, adjusting for potential covariates. Additionally, we stratified by knee extensor strength (high versus low).

RESULTS

Among women, compared to the highest quartile of hip abductor strength, the lowest quartile had 1.7 (95% confidence interval [95% CI] 1.1-2.6) times the odds of worsened knee pain; significant associations were limited to women with high knee extensor strength (odds ratio 2.0 [95% CI 1.1-3.5]). We found no relation of abductor strength to worsening knee pain in men or with incident frequent knee pain in men or women.

CONCLUSION

Hip abductor weakness was associated with worsening knee pain in women with strong knee extensors, but not with incident frequent knee pain in men or women. Knee extensor strength may be necessary, but not sufficient, to prevent pain worsening.

Can Clinicians Trust Objective Measures of Hip Muscle Strength From Portable Dynamometers? A Systematic Review With Meta-analysis and Evidence Gap Map of 107 Studies of Reliability and Criterion Validity Using the COSMIN Methodology

OBJECTIVE: To summarize the evidence on reliability and criterion validity of hip muscle strength testing using portable dynamometers. DESIGN: Systematic review with meta-analysis. LITERATURE SEARCH: Five databases were searched from inception to March 2023. STUDY SELECTION CRITERIA: We included studies investigating reliability or criterion validity of hip flexor, extensor, abductor, adductor, or internal/external rotator strength testing with portable dynamometers in injury-free individuals or those with pelvic/lower limb musculoskeletal disorders. DATA SYNTHESIS: We performed meta-analyses for each muscle group, position, and method of fixation. We rated pooled results as sufficient (>75% of studies with correlations ≥0.70), insufficient (>75% of studies with correlations <0.70), or inconsistent (sufficient/insufficient results). We assessed the quality of evidence, created evidence gap maps, and made clinical recommendations. RESULTS: We included a total of 107 studies (reliability 103, validity 14). The intrarater and interrater reliability for hip muscle strength testing across different positions and methods of fixation was sufficient (intraclass correlation coefficient = 0.78-0.96) with low- to high-quality evidence. Criterion validity was less investigated and mostly inconsistent (very low-to moderate-quality evidence) with a wide range of correlations (r = 0.40-0.93). CONCLUSION: Hip muscle strength testing using portable dynamometers is reliable. The use of portable dynamometers as clinical surrogates for measuring strength using an isokinetic dynamometer requires further investigation. Clinicians testing hip muscle strength with portable dynamometers should use external fixation seated for hip flexors, prone or supine for hip extensors, side-lying or supine for abductors and adductors, and prone and seated for internal and external rotators. J Orthop Sports Phys Ther 2023;53(11):655-672. Epub 3 October 2023. doi:10.2519/jospt.2023.12045.

Stem Design in Total Hip Arthroplasty Influences Ipsilateral Knee Valgus: A Retrospective Comparative Analysis of 2953 Cases

BACKGROUND

Total hip arthroplasty (THA) affects the biomechanics of the hip and the patient gait. The stem design influences femoral lever ratios and tissue trauma. Biomechanical changes such as these have the potential to induce knee arthritis. A varus or valgus configuration of knee arthritis is formed by asymmetric loadings. The aim of this study was to evaluate the impact of stem design in THA on knee valgus by comparing a standard implant with an implant with a short stem.

METHODS

A total of 2953 patients who underwent primary total knee arthroplasty for end-stage osteoarthritis between 2015 and 2021 were included in this retrospective data analysis. Patients were divided into three groups, depending on hip status (straight stem, short stem, and native joint). Leg alignment was distinguished as varus or valgus, and the degree of axial deviation was measured. Descriptive and explorative statistical analyses were performed, with a p value < 0.05 set as significant.

RESULTS

Ipsilateral knee valgus occurred significantly more often in patients with straight stems (57.2%) than in those with short stems (29%) and native joints (25.8%) (p < 0.001). Additionally, mean valgus deviation was significantly increased in patients with straight stems (8.9°) compared to those with short stems (6.4°) or native hip joints (6.7°). Both findings were accentuated in women.

CONCLUSIONS

Previous ipsilateral straight-stem THA is associated with knee valgus deformity, especially in women. Short-stem THA seems to be better suited to restoring physiological biomechanics and preventing the development of valgus osteoarthritis of the ipsilateral knee.

Absence of Improvement With Exercise in Some Patients With Knee Osteoarthritis: A Qualitative Study of Responders and Nonresponders

OBJECTIVE

To compare the perceptions of patients about why they did, or did not, respond to a physical therapist-supported exercise and physical activity program.

METHODS

This was a qualitative study within a randomized controlled trial. Twenty-six participants (of 40 invited) with knee osteoarthritis sampled according to response (n = 12 responders, and 14 nonresponders based on changes in both pain and physical function at 3 and 9 months after baseline) to an exercise and physical activity intervention. Semistructured individual interviews were conducted. Inductive thematic analysis was undertaken within each subgroup using grounded theory principles. A deductive approach compared themes and subthemes across subgroups. Findings were triangulated with quantitative data.

RESULTS

(Sub)themes common to responders and nonresponders included the intervention components that facilitated engagement, personal attitudes and expectations, beliefs about osteoarthritis and exercise role, importance of adherence, and perceived strength gains with exercise. In contrast to responders who felt empowered to self-manage, nonresponders accepted responsibility for lack of improvement in pain and function with exercise, acknowledging that their adherence to the intervention was suboptimal (confirmed by quantitative adherence data). Nonresponders believed that their excess body weight (supported by quantitative data) contributed to their outcomes, encountered exercise barriers (comorbidities, stressors, and life events), and perceived that the trial measurement tools did not adequately capture their response to exercise.

CONCLUSION

Responders and nonresponders shared some similar perceptions of exercise. However, along with perceived limitations in trial outcome measurements, nonresponders encountered challenges with excess weight, comorbidities, stressors, and life events that led to suboptimal adherence and collectively were perceived to contribute to nonresponse.

Association between ankle torque and performance-based tests, self-reported pain, and physical function in patients with knee osteoarthritis

Objectives

This study aimed to investigate the association between ankle torque and performance-based tests, self-reported pain, and physical function in patients with knee osteoarthritis (OA).

Patients and methods

The cross-sectional study was conducted with 39 individuals (24 females, 15 males; mean age: 57.3±6.2 years; range, 40 to 65 years) with knee OA between January 2014 and July 2015. Ankle torque was determined using an isokinetic dynamometer. The 40-m fast-paced walk test and a stair climb test were used to assess functional performance. Self-reported pain and physical function were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Pearson's correlation coefficients were calculated to test correlations between the dependent variables (40-m fast-paced walk test, stair climb test, WOMAC pain and physical function domains, sex, age, body mass index, and radiologic evidence of OA) and the independent variables (mean plantar flexor torque and dorsiflexor peak torque). A multiple linear regression analysis was applied to quantify the association between the dependent and independent variables.

Results

Dorsiflexor and plantar flexor peak torques in the concentric and eccentric modes were negatively correlated with the 40-m fast-paced walk and stair climb tests (r=-0.33 to -0.51, p≤0.05). A negative correlation was found between concentric plantar flexor torque and the WOMAC physical function score (r=-0.35, p=0.03). No correlation was found between ankle torques and the WOMAC pain score (p>0.05). The multiple linear regression analysis showed that the eccentric plantar flexor and dorsiflexor torques were significantly associated with the stair climb test (β=-0.001, 95% confidence interval [CI]: -0.001 to 0.000, p=0.03, and β=-0.002, 95% CI: -0.004 to 0.000, p=0.05, respectively). No significant associations were found between concentric plantar flexor and dorsiflexor torques and the stair climb test (p>0.05). No significant associations were found between the ankle torques and the 40-m fast-paced walk test and WOMAC physical function (p>0.05).

Conclusion

Ankle torque plays an important role in functional performance. Thus, ankle torque deficit, especially eccentric plantar flexor and dorsiflexor torques, may exert a negative influence on stair climbing performance in patients with knee osteoarthritis.

Sensorimotor or Balance Training to Increase Knee-Extensor and Knee-Flexor Maximal Strength in Patients With Knee Osteoarthritis: A Critically Appraised Topic

CLINICAL SCENARIO

Knee osteoarthritis (KOA) is a complex progressive synovial joint disease that results in impaired muscle function, including a considerable loss of maximal strength and power. Exercise therapies, such as sensorimotor or balance training and resistance training, are frequently used to improve muscle function, mobility, and quality of life, but their impact on maximal muscle strength in patients with KOA is not well understood.

FOCUSED CLINICAL QUESTION

Does sensorimotor or balance training improve knee-extensor and knee-flexor maximal muscle strength compared with strength training or no intervention in patients with KOA?

SUMMARY OF KEY FINDINGS

Results from 4 fair- to good-quality randomized controlled/clinical trials (level 1b) revealed inconsistent grade B evidence regarding the effect of sensorimotor or balance training to improve knee-extensor and knee-flexor maximal muscle strength in patients with KOA. Two studies, one good-quality study and one fair-quality study, showed significant strength improvements, and 2 good-quality studies demonstrated no significant strength enhancements.

CLINICAL BOTTOM LINE

Sensorimotor or balance training may be useful to improve maximal strength of quadriceps and hamstring muscle groups in patients with KOA; however, it seems that this depends on a training duration of at least 8 weeks and the use of unstable devices to induce destabilization of patients' balance, initiating neuromuscular adaptations.

STRENGTH OF RECOMMENDATION

Due to inconsistent evidence (grade B), the true effect of sensorimotor or balance training to improve knee-extensor and knee-flexor maximal muscle strength in patients with KOA remains unclear and needs to be further investigated.

Hip abduction angle after open-wedge high tibial osteotomy is associated with the timed up & go test and recurrence of varus alignment

The aim of this study is to investigate the association between the hip abduction angle (HAA) and lower limb alignment as well as the clinical assessments in open-wedge high tibial osteotomy (OWHTO) patients. A total of 90 patients who underwent OWHTO were included. The demographic characteristics and clinical assessments (the Visual Analogue Scale for activities of daily living, the Japanese knee osteoarthritis measure, the Knee injury and Osteoarthritis Outcome Score, the Knee Society score, the Timed Up & Go (TUG) test, the single standing (SLS) test and muscle strength) were recorded. The patients were divided into two groups according to the HAA at 1 month after operation: the HAA (-) group (HAA < 0°) and the HAA (+) group (HAA ≥ 0°). Clinical scores except for the SLS test and radiographic parameters except for the posterior tibia slope (PTS), lateral distal femoral angle (LDFA) and lateral distal tibial angle (LDTA) were significantly improved at 2 years postoperatively. Regarding the two groups, scores on the TUG test in the HAA (-) group were significantly lower than those in the HAA (+) group (p = 0.011). The hip-knee-ankle angle (HKA), weight bearing line (WBLR) and knee joint line obliquity (KJLO) in the HAA (-) group were significantly higher than those in the HAA (+) group (p < 0.001, 0.001 and p = 0.025). In contrast, the LDFA in the HAA (-) group were significantly lower than those in the HAA (+) group (p < 0.001). The TUG test and the LDFA were weakly positively correlated with the HAA (r = 0.34, 0.42, p < 0.001 and 0.001). In contrast, the HKA, WBLR and KJLO had a weak negative correlation with the HAA (r = - 0.43, - 0.38 and - 0.37, p < 0.001, 0.001 and 0.001). This study showed the postoperative HAA was significantly associated with the TUG test and the HKA, WBLR, LDFA, and KJLO. A higher postoperative HAA might induce varus recurrence and poor outcomes of the gait parameter.

Do we still need to screen our patients?-Orthopaedic scoring based on motion tracking

PURPOSE

Orthopaedic scores are essential for the clinical assessment of movement disorders but require an experienced clinician for the manual scoring. Wearable systems are taking root in the medical field and offer a possibility for the convenient collection of motion tracking data. The purpose of this work is to demonstrate the feasibility of automated orthopaedic scorings based on motion tracking data using the Harris Hip Score and the Knee Society Score as examples.

METHODS

Seventy-eight patients received a clinical examination and an instrumental gait analysis after hip or knee arthroplasty. Seven hundred forty-four gait features were extracted from each patient's representative gait cycle. For each score, a hierarchical multiple regression analysis was conducted with a subsequent tenfold cross-validation. A data split of 70%/30% was applied for training/testing.

RESULTS

Both scores can be reproduced with excellent coefficients of determination R2 for training, testing and cross-validation by applying regression models based on four to six features from instrumental gait analysis as well as the patient-reported parameter 'pain' as an offset factor.

CONCLUSION

Computing established orthopaedic scores based on motion tracking data yields an automated evaluation of a joint function at the hip and knee which is suitable for direct clinical interpretation. In combination with novel technologies for wearable data collection, these computations can support healthcare staff with objective and telemedical applicable scorings for a large number of patients without the need for trained clinicians.

The association between hip strength, physical function and dynamic balance in people with unilateral knee osteoarthritis: A cross-sectional study

BACKGROUND

In people with knee osteoarthritis, the association between multidirectional hip strength and physical function or balance is unknown.

OBJECTIVE

To determine the relationship between hip flexion, extension, abduction, adduction, external and internal rotation strength and (1) physical function and (2) dynamic balance.

DESIGN

Cross-sectional.

METHODS

Forty-seven participants (20 men and 27 women, age 66.2 ± 8.2 years) with unilateral knee osteoarthritis were included. Hip strength was assessed with hand-held dynamometry; physical function was assessed with the 40m fast-paced walk test (40mFPWT), 30-s chair-stand test (30sCST), and stair-climb test (SCT); and dynamic balance was assessed in 3 directions using the Star Excursion Balance Test. Multivariable linear regression analysis was used to determine the strength of relationships between measures.

RESULTS

Hip strength, in all directions except for internal rotation, was positively associated with better physical function (40mFPWT: R2 = 0.48 to 0.65; SCT: R2 = 0.5 to 0.54; 30sCST: R2 = 0.39 to 0.42), and dynamic balance (anterior: R2 = 0.33 to 0.45; posteromedial: R2 = 0.32 to 0.45; posterolateral: R2 = 0.27 to 0.35). Hip strength, after adjusting for knee extension strength, explained an additional 8%-12% (p < 0.05) and 5%-12% (p < 0.05) reach in the anterior and posteromedial directions of the Star Excursion Balance Test, respectively.

CONCLUSIONS

Hip strength in multiple directions is associated with measures of physical function and dynamic balance in people with unilateral knee osteoarthritis. Clinicians are encouraged to consider hip strength in multiple directions in the context of the patients' functional and/or balance goals when developing exercise programs for people with knee osteoarthritis.

Dry needling on latent and active myofascial trigger points versus oral diclofenac in patients with knee osteoarthritis: a randomized controlled trial

BACKGROUND

Latent and active myofascial trigger points (MTrPs) in knee-associated muscles may play a key role in pain management among patients with knee osteoarthritis (KOA). The aim of this study was to investigate the effect of dry needling treatment on pain intensity, disability, and range of motion (ROM) in patients with KOA.

METHODS

This randomized, single-blinded, clinical trial was carried out for 6 weeks of treatment and 6-month follow-up. A total of 98 patients met the entry criteria and were randomly assigned to the dry needling latent and active myofascial trigger point (MTrPs) with the stretching group or the oral diclofenacwith the stretching group. Numeric Pain Rating Scale (NPRS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and ROM were statistically analyzed before and after treatment and at the 6-month follow-up.

RESULTS

A total of 42 patients in the dry needling group (DNG) and 35 patients in the diclofenac group (DG), respectively, completed the study, and there was no significant difference in the general data between the two groups. After treatments, both the groups showed a good effect in knee pain, function, and ROM, However, the DNG showed a significantly better result than the DG. Especially in the results of the 6-month follow-up, the DNG showed much better results than the DG.

CONCLUSIONS

Dry needling on latent and active MTrPs combined with stretching and oral diclofenac combined with stretching can effectively relieve pain, improve function, and restore knee ROM affected by KOA. However, the effects of dry needling and stretching are better and longer lasting than those of oral diclofenac and stretching for at least 6 months.

TRIAL REGISTRATION

Registered in the Chinese Clinical Trial Registry ( www.chictr.org.cn ) in 17/11/2017 with the following code: ChiCTR-INR-17013432.

Association of preoperative muscle composition of the lower extremity with gait function after total knee arthroplasty

BACKGROUND

Limitations of gait function persist in some patients with knee osteoarthritis after total knee arthroplasty. This study aimed to identify preoperative muscle composition variables of the operated limb associated with postoperative gait function.

METHODS

Longitudinal data from 45 patients who underwent unilateral primary total knee arthroplasty were retrospectively analyzed. Timed Up-and-Go test and gait speed were measured preoperatively and at 3 and 6 months postoperatively. Preoperative muscle composition in the glutei medius and minimus, the quadriceps, the hamstrings, and combination of the hamstrings and quadriceps were evaluated by computed tomography. The area ratio of the individual muscle composition to the total muscle was calculated. The factors associated with Timed Up-and-Go test and gait speed were identified using stepwise regression analysis.

RESULTS

Shorter Timed Up-and-Go test and faster gait speed at each time point correlated with higher lean muscle mass area of the total hamstrings, higher area ratio of lean muscle mass to the total hamstrings or to combination of the hamstrings and quadriceps, and lower area ratio of low density lean tissue or intramuscular adipose tissue to the total hamstrings. Shorter Timed Up-and-Go test at each time point also correlated with higher combined area of lean muscle mass of the hamstrings and quadriceps. Faster gait speed at each time point additionally correlated with lower area ratio of intramuscular fat to the total hamstrings and lower area ratio of lean tissue mass or intramuscular adipose tissue to combination of the hamstrings and quadriceps. Regression analysis using the significant muscle composition variables revealed that the area ratio of lean muscle mass to the total hamstrings was the only predictor of Timed Up-and-Go test and gait speed after operation.

CONCLUSIONS

Preoperative area ratio of ipsilateral lean muscle mass to the total hamstrings could predict gait function after total knee arthroplasty.

Intra-Articular Mesenchymal Stem Cell Injection for Knee Osteoarthritis: Mechanisms and Clinical Evidence

Knee osteoarthritis presents higher incidences than other joints, with increased prevalence during aging. It is a progressive process and may eventually lead to disability. Mesenchymal stem cells (MSCs) are expected to repair damaged issues due to trilineage potential, trophic effects, and immunomodulatory properties of MSCs. Intra-articular MSC injection was reported to treat knee osteoarthritis in many studies. This review focuses on several issues of intra-articular MSC injection for knee osteoarthritis, including doses of MSCs applied for injection and the possibility of cartilage regeneration following MSC injection. Intra-articular MSC injection induced hyaline-like cartilage regeneration, which could be seen by arthroscopy in several studies. Additionally, anatomical, biomechanical, and biochemical changes during aging and other causes participate in the development of knee osteoarthritis. Conversely, appropriate intervention based on these anatomical, biomechanical, biochemical, and functional properties and their interactions may postpone the progress of knee OA and facilitate cartilage repair induced by MSC injection. Hence, post-injection rehabilitation programs and related mechanisms are discussed.

Neuromuscular joint function in knee osteoarthritis: A systematic review and meta-analysis

BACKGROUND

Neuromuscular alterations are common in people with knee osteoarthritis (KOA). A comprehensive understanding of these alterations is important to enable targeted rehabilitation strategies.

OBJECTIVES

This systematic review and meta-analysis aimed to comprehensively understand the neuromuscular alterations around the knee joint in people with KOA.

METHODS

Moderate- and high-quality studies based on a modified version of the Downs and Black checklist, comparing neuromuscular function of peri‑articular muscles between people with KOA and controls were retrieved from five databases from inception to October 2020. Outcomes included normalized isokinetic strength, muscle size, voluntary activation, cortical and spinal-reflex excitability, and torque-related outcomes. Data were pooled according to structural KOA severity with sensitivity analysis based on sex. Evidence levels are presented in evidence gap maps.

RESULTS

A total of 7 high-quality and 22 moderate-quality studies were retained (1146 people with KOA and 1353 age- and sex-matched controls). Studies demonstrated quadriceps and hamstring strength deficits and increased hamstring-to-quadriceps strength ratios across KOA severities. Women presented lower quadriceps strength at early KOA (very limited evidence) and lower voluntary activation at end stage KOA (very limited evidence) as compared with controls, whereas men did not (moderate evidence). People with KOA also demonstrated lower quadriceps force control ability with no change in rapid force production (very limited evidence). Voluntary activation deficits for quadriceps were evident (moderate evidence), with no change in quadriceps cortical excitability (very limited evidence) or soleus spinal reflexes (very limited evidence). No muscle size change was demonstrated except for the vastus medialis (limited evidence). Evidence gaps were found for neural and torque-related measures and differences in hamstring, gastrocnemius, soleus, and popliteus.

CONCLUSIONS

Neuromuscular deficits are evident across different structural KOA severities and are seen in muscle strength, voluntary activation, muscle size, and force control ability. Women may exhibit these alterations to a greater extent than men.

PROSPERO REGISTRATION NUMBER

CRD42019160845.

The effect of hip abductor fatigue on knee kinematics and kinetics during normal gait

Objective

To investigate the effect of hip abductor fatigue on the kinematics and kinetics of the knee joint during walking in healthy people to provide a new approach for the prevention and treatment of knee-related injuries and diseases.

Methods

Twenty healthy participants, ten females, and ten males, with a mean age of 25.10 ± 1.2 years, were recruited. Isometric muscle strength testing equipment was used to measure the changes in muscle strength before and after fatigue, and the surface electromyography (SEMG) data during fatigue were recorded synchronously. The Vicon system and an AMTI© force platform were used to record the kinematic parameters and ground reaction force (GRF) of twenty participants walking at a self-selected speed before and after fatigue. Visual 3D software was used to calculate the angles and torques of the hip and knee joints.

Results

After fatigue, the muscle strength, median frequency (MF) and mean frequency (MNF) of participants decreased significantly (P < 0.001). The sagittal plane range of motion (ROM) of the knee (P < 0.0001) and hip joint (P < 0.01) on the fatigue side was significantly smaller than before fatigue. After fatigue, the first and second peaks of the external knee adduction moment (EKAM) in participants were greater than before fatigue (P < 0.0001), and the peak values of the knee abduction moment were also higher than those before fatigue (P < 0.05). On the horizontal plane, there is also a larger peak of internal moment during walking after fatigue (P < 0.01).

Conclusion

Hip abductor fatigue affects knee kinematics and kinetics during normal gait. Therefore, evaluating hip abductor strength and providing intensive training for patients with muscle weakness may be an important part of preventing knee-related injuries.

Hip abductor versus adductor strengthening for clinical outcomes in knee symptomatic osteoarthritis: A randomized controlled trial

BACKGROUND

Hip adductors and abductors are weak in patients with knee osteoarthritis (KOA). However, most studies have not investigated selective adductor strengthening.

OBJECTIVE

To compare the effects of adding selective hip abductors versus adductors strengthening to lower limb multimodal exercise program for pain, self-reported function, knee-related quality of life, medication ingested and performance-based tests in patients with symptomatic KOA.

DESING

Randomized controlled trial.

METHODS

Sixty-six patients with KOA were randomly assigned to two treatment groups: hip abductor group (HABG) or hip adductor group (HADG). Both groups performed a lower limb multimodal exercise program. HABG and HADG groups added three hip abduction and three hip adduction exercises, respectively. Intensity of pain through numeric pain scale, Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales, Lequesne questionnaire, global perceived effect scale, medication ingested, performance-based tests were assessed at baseline, after 6 weeks, and 6 months.

RESULTS

No significant between-group differences were found in primary outcomes: pain intensity (mean difference = -1.15, 95%CI -2.44 - 0.12, P = 0.07), KOOS-pain (mean difference = 1.64, 95%CI -6.79 - 10.07, P = 0.70) and KOOS-function in daily living (mean difference = -0.12, 95%CI, -8.78 - 8.54, P = 0.97) in 6 weeks. Groups did not differ in any secondary outcome after 6 weeks or after 6 months (P > 0.05).

CONCLUSIONS

There is no difference between adding hip abductors or adductors strengthening to lower limb multimodal exercise program in improving pain, self-reported function, quality of life, medication ingested and performance-based tests in patients with KOA.

Hip abductor strengthening in patients diagnosed with knee osteoarthritis - a systematic review and meta-analysis

BACKGROUND

Globally osteoarthritis of the knee is a leading cause of disability. Hip abductor strength and activation are essential for maintaining postural balance during transfers and are related to joint loading and progression during weight-bearing activities. Strength deficits in the hip abductors might cause a reduction in the lower extremity force generation, thereby causing stress on the medial tibiofemoral joint. The aim of this systematic review is to assess the effectiveness of hip abductor strengthening on knee joint loading, knee pain and functional outcome measures in patients with knee osteoarthritis.

METHODS

Database such as Scopus, PubMed, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL) database and PEDro were reviewed to recognize the trials published in English from inception to December 2020. Randomized controlled trials that studied the effectiveness of hip abductor strengthening in subjects with knee osteoarthritis and its impact on knee joint loading, knee pain and functional outcome measures were included. RevMan 5.4 was used for meta-analysis and forest plot construction. Quality assessment of the included studies was carried out using the PEDro scale.

RESULTS AND DISCUSSION

The search yielded 260 results of which 29 full-text articles were screened. The review includes 7 randomized controlled trials and 3 studies with good methodological quality were included for meta-analysis. The meta-analysis of the articles favored hip abductor strengthening intervention over the control group. Hip abductor strengthening had significantly reduced the VAS [ SMD = -0.60[-0.88, -0.33] p < 0.0001]at 95% CI and improved the WOMAC scores [SMD - 0.75[-1.05,-0.45] p < 0.0001] at 95% CI. All of the included studies concluded that strengthening the hip abductor muscle had a positive impact on knee pain and functional outcomes.

CONCLUSION

The current study found high-quality evidence to support the use of hip abductor muscle strengthening exercises as a rehabilitative treatment for subjects with knee osteoarthritis.

TRIAL REGISTRATION

CRD42021256251 .

Compensatory Responses During Slip-Induced Perturbation in Patients With Knee Osteoarthritis Compared With Healthy Older Adults: An Increased Risk of Falls?

Background: Functional impairment of the knee joint affected by osteoarthritis and loss of muscle strength leads to a significant increase in the number of falls. Nevertheless, little is known about strategies for coping with gait perturbations in patients with knee osteoarthritis (KOA). Thus, this study aimed to examine the compensatory strategies of patients with KOA in response to a backward slip perturbation compared with healthy older adults.

Methods: An automated perturbation program was developed by using D-Flow software based on the Gait Real-time Analysis Interactive Lab, and an induced backward slip perturbation was implemented on nine patients with severe KOA (68.89 ± 3.59 years) and 15 age-matched healthy older adults (68.33 ± 3.29 years). Step length, gait speed, range of motion, vertical ground reaction forces, lower extremity joint angles, and joint moments were computed and analyzed.

Results: Compared with older adults, patients with KOA had significantly lower step length, gait speed, and vertical ground reaction forces in both normal walking and the first recovery step following backward slip perturbations. Inadequate flexion and extension of joint angles and insufficient generation of joint moments predispose patients with KOA to fall. Hip extension angle and flexion moment, knee range of motion, and vertical ground reaction forces are key monitoring variables.

Conclusion: The risk of falls for patients with KOA in response to backward slip perturbations is higher. Patients with KOA should focus not only on quadriceps muscle strength related to knee range of motion but also on improving hip extensor strength and activation through specific exercises. Targeted resistance training and perturbation-based gait training could be better options.

Hip strength, quadriceps strength and dynamic balance are lower in people with unilateral knee osteoarthritis compared to their non-affected limb and asymptomatic controls

BACKGROUND

There is insufficient literature on multi-directional hip strength differences and dynamic balance between people with knee osteoarthritis (KOA) and healthy controls.

OBJECTIVE

In people with unilateral KOA, determine if hip/knee strength and dynamic balance differs (i) between sides, and (ii) compared to controls.

METHODS

Thirty-six participants (17 women; 65.5 ± 8.9 years) with unilateral KOA and 36 age- and sex-matched controls were included in a cross-sectional study. Outcomes included hip strength, quadriceps strength, and dynamic balance (three directions) during the Star Excursion Balance Test. Mixed ANOVA analysis was completed to investigate differences between Limbs and Groups. Mean differences (MD) and 95% confidence intervals (CI) were calculated.

RESULTS

Quadriceps and hip adduction strength were 16% (95%CI:10, 22) and 9% [95%CI: 3, 16) lower on the affected compared to non-affected side. Quadriceps and hip abduction, adduction, flexion, and extension strength (MD varying from 16%, 95%CI: 8, 25; to 34%, 95%CI: 17, 50) were weaker bilaterally in individuals with KOA compared to control. Posteromedial balance was 4% (95%CI: 2, 6) lower for affected compared to non-affected limbs in those with KOA and 13% (95%CI: 6, 21) lower in the affected limb compared to controls. Individuals with KOA had lower balance bilaterally in the anterior 11% (95%CI: 7, 15) and posterolateral 21% (95%CI: 13, 30) directions.

CONCLUSION

Hip/knee strength (especially in the sagittal and frontal planes) and dynamic balance are lower bilaterally in people with KOA compared to controls. Hip adduction strength is lower on the affected than non-affected limbs of people with KOA. Clinicians should consider that knee extension strength, hip strength, and dynamic balance are lower bilaterally in people with unilateral KOA.

Neuromuscular Function of the Knee Joint Following Knee Injuries: Does It Ever Get Back to Normal? A Systematic Review with Meta-Analyses

BACKGROUND

Neuromuscular deficits are common following knee injuries and may contribute to early-onset post-traumatic osteoarthritis, likely mediated through quadriceps dysfunction.

OBJECTIVE

To identify how peri-articular neuromuscular function changes over time after knee injury and surgery.

DESIGN

Systematic review with meta-analyses.

DATA SOURCES

PubMed, Web of Science, Embase, Scopus, CENTRAL (Trials).

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Moderate and high-quality studies comparing neuromuscular function of muscles crossing the knee joint between a knee-injured population (ligamentous, meniscal, osteochondral lesions) and healthy controls. Outcomes included normalized isokinetic strength, muscle size, voluntary activation, cortical and spinal-reflex excitability, and other torque related outcomes.

RESULTS

A total of 46 studies of anterior cruciate ligament (ACL) and five of meniscal injury were included. For ACL injury, strength and voluntary activation deficits were evident (moderate to strong evidence). Cortical excitability was not affected at < 6 months (moderate evidence) but decreased at 24+ months (moderate evidence). Spinal-reflex excitability did not change at < 6 months (moderate evidence) but increased at 24+ months (strong evidence). We also found deficits in torque variability, rate of torque development, and electromechanical delay (very limited to moderate evidence). For meniscus injury, strength deficits were evident only in the short-term. No studies reported gastrocnemius, soleus or popliteus muscle outcomes for either injury. No studies were found for other ligamentous or chondral injuries.

CONCLUSIONS

Neuromuscular deficits persist for years post-injury/surgery, though the majority of evidence is from ACL injured populations. Muscle strength deficits are accompanied by neural alterations and changes in control and timing of muscle force, but more studies are needed to fill the evidence gaps we have identified. Better characterisation and therapeutic strategies addressing these deficits could improve rehabilitation outcomes, and potentially prevent PTOA.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42019141850.

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.

Contribution of hip and knee muscles to lateral knee stability during gait

[Purpose] Lateral knee instability is frequently observed in patients with knee injury or risk factors associated with knee osteoarthritis. Physical exercises can strengthen muscles that stabilize the knee joint. The purpose of this study was to define the contribution of the knee and hip muscles to lateral knee stability by comparing the muscle forces, as assessed by musculoskeletal simulation using one or two degrees-of-freedom (1-DOF and 2-DOF) knee models. [Participants and Methods] We evaluated the normal gait of 15 healthy subjects. We conducted a three-dimensional gait analysis using a motion analysis system and a force plate. We considered a muscle as a lateral knee stabilizer when the calculated muscle force was greater with the 2-DOF model than with the 1-DOF model. [Results] During early and late stance, the muscle forces of the lateral knee and hip joint increased in the 2-DOF model as opposed to in the 1-DOF model. In contrast, the forces of the medial knee muscles decreased. Furthermore, hip muscle forces increased during the late stance. [Conclusion] Our results show that the lateral knee and hip muscles contribute to lateral knee stability. Thus, exercises to strengthen these muscles could improve lateral knee stability.

Limited Support for Trunk and Hip Deficits as Risk Factors for Athletic Knee Injuries: A Systematic Review With Meta-analysis and Best-Evidence Synthesis

OBJECTIVE

To determine whether neuromuscular deficits in trunk and hip-related function are risk factors for athletic knee injuries.

DESIGN

Etiology systematic review with meta-analysis.

LITERATURE SEARCH

Six online databases (MEDLINE, Web of Science, Embase, CINAHL, Scopus, and SPORTDiscus) were searched up to April 2019.

STUDY SELECTION CRITERIA

Studies assessing trunk and hip neuromuscular function as risk factors for knee injuries in healthy athletic populations were included.

DATA SYNTHESIS

Outcomes were synthesized quantitatively using meta-analysis of odds ratios, and qualitatively using best-evidence synthesis.

RESULTS

Twenty-one studies met the inclusion criteria. There was very low-certainty evidence that greater hip external rotation strength protected against knee injuries (odds ratio = 0.78; 95% confidence interval: 0.70, 0.87; P<.05). There was limited evidence that deficits in trunk proprioception and neuromuscular control, and the combination of excessive knee valgus and ipsilateral trunk angle when landing unilaterally from a jump, may be risk factors for knee injuries.

CONCLUSION

Most variables of trunk and hip function were not risk factors for injuries. Further research is required to confirm whether hip external rotation strength, trunk proprioception and neuromuscular control, and the combination of knee valgus angle and ipsilateral trunk control are risk factors for future knee injuries. J Orthop Sports Phys Ther 2020;50(9):476-489. Epub 1 Aug 2020. doi:10.2519/jospt.2020.9705.

Hip abductor muscle strength in patients after total or unicompartmental knee arthroplasty for knee osteoarthritis or avascular necrosis: a systematic review and meta-analysis protocol

INTRODUCTION

Reduced hip abductor strength may indirectly lead to changes in knee kinematics and functional impairment and has been reported in patients with patellofemoral pain and knee osteoarthritis (OA). Limited information is available regarding hip abductor strength following total or unicompartmental knee arthroplasty (TKA/UKA). The aims of this systematic review are to synthesise the evidence of hip abductor muscle strength deficits in patients following TKA/UKA and to determine influencing factors for these deficits.

METHODS AND ANALYSIS

Embase, Medline, SportDiscus, the Web of Science Core Collection and Scopus will be searched for human-based clinical studies investigating hip abductor muscle strength after TKA/UKA for knee OA or avascular necrosis (AVN). Articles studying hip abductor strength after knee arthroplasty for post-traumatic OA will not be considered. No restriction on study design, prosthesis design, surgical approach, patient characteristics or severity of OA/AVN will be applied. We will search articles published between 1 January 1990 and the date of our last search. Only articles in English or German language will be considered for inclusion. Studies reporting manually measured muscle strength or measurements performed at hip abduction angles other than 0° will be excluded. References will be screened by two reviewers independently. Where necessary, a third author will make the final decision. The assessment of quality and risk of bias will be performed with the modified Newcastle-Ottawa scale. Data will be extracted and presented in a tabular form. Depending on availability, comparable subgroup and meta-analyses will be conducted. Patient characteristics such as age, sex and surgical approach or rehabilitation programme will be analysed, if sufficient data are available.

ETHICS AND DISSEMINATION

No ethics approval is required. The results will be published in a peer-reviewed journal and as conference presentation.

Hip abductor muscle weakness and slowed turning motion in people with knee osteoarthritis

Laser range sensor-based timed up and go (laser-TUG) test can evaluate performance in TUG subtasks (sit-to-walk [STW], walking a short distance, and turning). This study aimed to test the hypothesis that weaker hip abductor muscle strength is more significantly associated with slowed turning speed than with the other TUG subtasks (STW and straight walking) after controlling for quadriceps muscle strength in patients with knee osteoarthritis (OA). Community-dwelling participants with knee OA (Kellgren and Lawrence [K&L] grade ≥ 1; mean age, 68.6 years; 70.3% women) underwent laser-TUG. Spatiotemporal gait parameters in TUG and the TUG subtasks were evaluated as outcome measures. The isometric muscle strength of the hip abductor and quadriceps was measured using a hand-held dynamometer. Multiple linear regression analysis was performed to examine the relationship between muscle strength as an independent variable and spatiotemporal parameters as dependent variables. The relative importance of hip abductor muscle strength was determined using the percentages of unique variance. Participants with weaker hip abductor muscle strength demonstrated 0.094 m/s slower turning speed after adjustment for covariates including quadriceps muscle strength. The unique variance explained by hip abductor muscle strength in turning speed was 2.1%. However, no significant relationships were confirmed between weak hip abductor muscle strength and the time to perform TUG and the straight walking (forward and return) phase. These findings indicate that turning motion may be more sensitive to aggravated hip abductor muscle weakness and may show better response to hip muscle strengthening exercises. Longitudinal studies are warranted to elucidate this issue.

Relative difference in muscle strength between patients with knee osteoarthritis and healthy controls when tested bilaterally and joint-inclusive: an exploratory cross-sectional study

Background

To improve the goal-directedness of strength exercises for patients with knee osteoarthritis (KOA), physical rehabilitation specialists need to know which muscle-groups are most substantially weakened across the kinetic chain of both lower extremities. The purpose was to improve the knowledge base for strength exercise therapy. The objective was to explore the relative differences in muscle strength in the main directions bilaterally across the hip, knee, and ankle joints between patients with light-to-moderate symptomatic and radiographic KOA and people without knee complaints.

Methods

The design was an exploratory, patient vs. healthy control, and cross-sectional study in primary/secondary care. Twenty-eight patients with mild to moderate KOA (18 females, mean age 61) and 31 matched healthy participants (16 females, mean age 55), participated. Peak strength was tested concentrically or isometrically in all main directions for the hip, knee, and ankle joints bilaterally, and compared between groups. Strength was measured by a Biodex Dynamometer or a Commander II Muscle Tester (Hand-Held Dynamometer). Effect sizes (ES) as Cohen’s d were applied to scale and rank the difference in strength measures between the groups. Adjustment for age was performed by analysis of covariance.

Results

The most substantial muscle weaknesses were found for ankle eversion and hip external and internal rotation in the involved leg in the KOA-group compared to the control-group (ES [95% CI] −0.73 [−1.26,-0.20], − 0.74 [−1.26,-0.21], −0.71 [−1.24,-0.19], respectively; p < 0.01). Additionally, smaller but still significant moderate muscle weaknesses were indicated in four joint–strength directions: the involved leg’s ankle inversion, ankle plantar flexion, and knee extension, as well as the uninvolved leg’s ankle dorsal flexion (p < 0.05). There was no significant difference for 17 of 24 tests.

Conclusions

For patients with KOA between 45 and 70 years old, these explorative findings indicate the most substantial weaknesses of the involved leg to be in ankle and hip muscles with main actions in the frontal and transverse plane in the kinetic chain of importance during gait. Slightly less substantial, they also indicate important weakness of the knee extensor muscles. Confirmatory studies are needed to further validate these exploratory findings.

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.

Does adding hip exercises to quadriceps exercises result in superior outcomes in pain, function and quality of life for people with knee osteoarthritis? A systematic review and meta-analysis

Objectives

To determine, in people with knee osteoarthritis (KOA): i) the effectiveness of adding hip strengthening exercises to quadriceps exercises and ii) the type of hip strengthening exercise with the greatest evidence for improving pain, function and quality of life.

Design

Systematic review with meta-analysis.

Data sources

Medline, Embase, Cochrane, CINAHL and SportDiscus databases were searched from inception to January 2018.

Eligibility criteria for selecting studies

Randomised controlled trials investigating the effect of adding hip exercises to quadriceps exercises in people with KOA on pain, function and/or quality of life were included. Three subgroups of hip exercises were included: resistance, functional neuromuscular or multimodal exercise.

Results

Eight studies were included. Pooled data provide evidence that combined hip and quadriceps exercise is significantly more effective than quadriceps exercise alone for improving walking function (standardised mean difference −1.06, 95% CI −2.01 to −0.12), but not for outcomes of pain (−0.09, 95% CI –0.96 to 0.79), patient-reported function (−0.74, 95% CI –1.56 to 0.08) or stair function (−0.7, 95% CI –1.67 to 0.26). Subgroup analyses reveal that hip resistance exercises are more effective than functional neuromuscular exercises for improving pain (p<0.0001) and patient-reported function (p<0.0001). Multimodal exercise is no more effective than quadriceps strengthening alone for pain (0.13, 95% CI –0.31 to 0.56), patient-reported function (−0.15, 95% CI –0.58 to 0.29) or stair function (0.13, 95% CI –0.3 to 0.57).

Conclusion

Walking improved after the addition of hip strengthening to quadriceps strengthening in people with KOA. The addition of resistance hip exercises to quadriceps resulted in greater improvements in patient-reported pain and function.

Muscle size and composition in people with articular hip pathology: a systematic review with meta-analysis

OBJECTIVE

To synthesise and evaluate the current evidence investigating muscle size and composition in non-inflammatory articular hip pathology.

METHODS

A systematic review of five electronic databases, using three concepts; articular hip pathology (e.g., osteoarthritis (OA)); hip muscles; and outcomes (e.g., muscle size and adiposity) was undertaken. Studies addressing non-inflammatory or non-traumatic articular hip pain, using measures of muscle size and adiposity were included and appraised for risk of bias. Data was extracted to calculate standardised mean differences (SMD) and pooled where possible for meta-analysis.

RESULTS

Thirteen cross-sectional studies were included; all studies measured muscle size and 5/13 measured adiposity. In OA, there was low to very low quality evidence of no difference in hip muscle size, compared with matched controls. In unilateral OA, there was low to very low quality evidence of smaller size in gluteus minimus (SMD -0.38; 95% confidence interval (CI) -0.74, -0.01), gluteus medius (-0.44; 95% CI: -0.83, -0.05) and gluteus maximus (-0.39; 95% CI: -0.75, -0.02) muscles in the symptomatic limb. Individual studies demonstrated non-uniform changes in muscle size in OA. No significant difference was observed in muscle size in other pathologies or in adiposity for any group.

CONCLUSION

There is some low quality evidence that specific hip muscles are smaller in unilateral hip OA. Variation in the magnitude of differences indicate changes in size are not uniform across all muscles or stage of pathology. Studies in larger cohorts investigating muscle size and composition across the spectrum of articular pathologies are required to clarify these findings.

Trunk movement asymmetry associated with pain, disability, and quadriceps strength asymmetry in individuals with knee osteoarthritis: a cross-sectional study

OBJECTIVE

This study examined 1) the clinical relevance of trunk movement asymmetry, which was evaluated using a trunk-mounted inertial measurement unit (IMU), and 2) the relationship between trunk movement asymmetry and lower limb muscle strength asymmetry in individuals with knee osteoarthritis (OA).

DESIGN

One-hundred-thirty-one participants (mean age, 74.2 years; 71.8% female; Kellgren and Lawrence [K&L] grade ≥1) underwent gait analysis at their preferred pace for IMU-based measurement of trunk movement asymmetry (harmonic ratio [HR] and improved HR). The isometric strength of quadriceps and hip abductors was evaluated using a hand-held dynamometer. Pain and disability level were evaluated using a validated self-reported questionnaire. Multiple regression analyses with covariate adjustment were performed to examine the relationship between trunk movement asymmetry (independent variable) and pain, disability level, or muscle strength asymmetry (dependent variables).

RESULTS

Individuals with severe knee OA (K&L grade ≥3) had increased trunk movement asymmetry in the medio-lateral axis compared to those with a K&L grade of 1. Increased trunk movement asymmetry was associated with a greater knee pain and disability. The increased trunk movement asymmetry was significantly associated with an increase in the asymmetry of quadriceps strength, but not with asymmetry in the strength of hip abductor.

CONCLUSION

Our findings indicate that increased medio-lateral trunk movement asymmetry may be an indicator of impairment, rather than adaptation, in individuals with knee OA. This preliminary finding warrants validation by future study. Paying close attention to medio-lateral trunk movement asymmetry may be key to our understanding of OA-related pain and disability.

Self-reported social and activity restrictions accompany local impairments in posterior tibial tendon dysfunction: a systematic review

BACKGROUND

Posterior tibial tendon dysfunction (PTTD) is a painful, progressive tendinopathy that reportedly predominates in middle-age, overweight women. There is no evidence based guidelines that clinicians can use to guide treatment planning, which leaves clinicians to make decisions on the basis of presenting clinical impairments and self-reported pain and disability. The purpose of this systematic review was to quantify clinical impairments, pain and disability in individuals with PTTD compared with controls.

METHODS

Five databases were searched for terms referring to the posterior tibial tendon and flatfoot up to and including 11 March 2018. The systematic review was registered with PROSPERO (CRD: 42016046951). Studies were eligible if they were published in the English language and contained data on clinical impairments, pain or disability compared between participants diagnosed with PTTD and pain-free individuals. Standardised mean differences (SMDs) were calculated where possible and meta-analysis was performed when homogeneity of outcomes allowed.

RESULTS

Ten eligible studies were identified and pooled in the meta-analyses. Strong effects were revealed for poor heel rise endurance (SMD -1.52, 95% CI -2.05 to - 0.99), less forefoot adduction-inversion strength (SMD -1.19, 95% CI -1.68 to - 0.71) and lower arch height (SMD -1.76, 95% CI -2.29 to - 1.23). Compared to controls, individuals with PTTD also had more self-reported stiffness (SMD 1.45, 95% CI 0.91 to 1.99), difficulties caused by foot problems (SMD 1.42, 95% CI 0.52 to 2.33) and social restrictions (SMD1.26, 95% CI 0.25 to 2.27).

CONCLUSION

There is evidence of impaired tibialis posterior capacity and lowered arch height in individuals with PTTD compared to controls. Further to addressing the expected impairments in local tendon function and foot posture, pain, stiffness, functional limitations and social participation restrictions should be considered when managing PTTD.

Timing of Frontal Plane Trunk Lean, Not Magnitude, Mediates Frontal Plane Knee Joint Loading in Patients with Moderate Medial Knee Osteoarthritis

The purpose of this study was to examine the influence of trunk lean and contralateral hip abductor strength on the peak knee adduction moment (KAM) and rate of loading in persons with moderate medial knee osteoarthritis. Thirty-one males (17 with osteoarthritis, 14 controls) underwent 3-dimensional motion analysis, strength testing of hip abductors, and knee range of motion (ROM) measures, as well as completing the knee osteoarthritis outcome score (KOOS). No differences were found between groups or limbs for gait cycle duration, but the osteoarthritis group had longer double-limb support during weight acceptance (p < 0.001) and delayed frontal plane trunk motion towards the stance limb (p < 0.01). This was reflected by a lower rate of loading for the osteoarthritis group compared to controls (p < 0.001), whereas no differences were found for peak KAM. Trunk angle, contralateral hip abductor strength, and BMI explained the rate of loading at the involved knee (p < 0.001), an association not found for the contralateral knee or control knees. Prolonged trunk lean over the stance limb may help lower peak KAM values. Rate of frontal plane knee joint loading may partly be mediated by the contralateral limb's abductor strength, accentuating the importance of bilateral lower limb strength for persons with knee osteoarthritis.

Biomechanical characteristics of stair ambulation in patients with knee OA: A systematic review with meta-analysis toward a better definition of clinical hallmarks

BACKGROUND

Stair climbing was suggested to be the first affected task in individuals with knee osteoarthritis (OA).

RESEARCH QUESTION

This review aimed to identify consistent kinematic, kinetic, and spatiotemporal alterations of stair climbing exhibited by individuals with knee OA.

METHODS

A literature search published until September 2017 was conducted in PubMed, PEDro, CINAHL, and Cochrane CENTRAL. Reviewer extracted data in accordance with the Cochrane Handbook. Where possible, data were combined into a meta-analysis; the pooled standardized mean differences between individuals with knee OA and healthy adults were calculated using the random-effect model.

RESULTS

In total, 585 potentially relevant articles were selected, of which 12 (695 participants, mean age: 58.4 years) met the inclusion criteria. Meta-analysis revealed that kinematic and kinetic alterations during stair climbing associated with knee OA were lower external knee flexion moment in conjunction with a larger trunk/hip flexion angles and smaller knee flexion/ankle dorsiflexion angles. Individuals with knee OA showed a delayed quadriceps activation during stair ascent. A lack of evidence was detected for alterations in external knee adduction moment during stair climbing. Effect estimate in each meta-analysis was judged "very low" on the GRADE approach.

SIGNIFICANCE

No strong conclusion can be drawn because of the low quality of evidence; however, individuals with knee OA may exhibit altered kinematics and kinetics changes in sagittal plane during stair climbing, and have delayed quadriceps muscle activity. Further studies with adequate adjustment for confounders are warranted to facilitate clinical hallmarks of the knee OA, particularly in early stages of the disease.

Adductor magnus: An EMG investigation into proximal and distal portions and direction specific action

Cadaveric studies indicate that adductor magnus is structurally partitioned into at least two regions. The aim of this study was to investigate the direction-specific actions of proximal and distal portions of adductor magnus, and in doing so determine if these segments have distinct functional roles. Fine-wire EMG electrodes were inserted into two portions of adductor magnus of 12 healthy young adults. Muscle activity was recorded during maximum voluntary isometric contractions (MVICs) across eight tests (hip flexion/extension, internal/external rotation, abduction, and adduction at 0°, 45°, and 90° hip flexion). Median activity within each action (normalized to peak) was compared between segments using repeated measures nonparametric tests (α = 0.05). An effect size (ES = z-score/√sample size) was calculated to determine the magnitude of difference between muscle segments. The relative contribution of each muscle segment differed significantly during internal rotation (P < 0.001; ES = 0.88) and external rotation (P = 0.003, ES = 0.79). The distal portion was most active during extension [median (interquartile range); 100(0)% MVIC)] and internal rotation [58(34)% MVIC]. The proximal portion was most active during extension [100(49)% MVIC] and adduction [59(64)%MVIC], with low level activity during external rotation [15(41)%MVIC]. This study suggests that adductor magnus has at least two functionally unique regions. Differences were most evident during rotation. The different direction-specific actions may imply that each segment performs separate roles in hip stability and movement. These findings may have implications on injury prevention and rehabilitation for adductor-related groin injuries, hamstring strain injury, and hip pathology. Clin. Anat. 31:535-543, 2018. © 2018 Wiley Periodicals, Inc.

Gluteus Minimus and Gluteus Medius Muscle Activity During Common Rehabilitation Exercises in Healthy Postmenopausal Women

Study Design Controlled laboratory study, cross-sectional. Background The gluteus medius (GMed) and gluteus minimus (GMin) provide dynamic stability of the hip joint and pelvis. These muscles are susceptible to atrophy and injury in individuals during menopause, aging, and disease. Numerous studies have reported on the ability of exercises to elicit high levels of GMed activity; however, few studies have differentiated between the portions of the GMed, and none have examined the GMin. Objectives To quantify and rank the level of muscle activity of the 2 segments of the GMin (anterior and posterior fibers) and 3 segments of the GMed (anterior, middle, and posterior fibers) during 4 isometric and 3 dynamic exercises in a group of healthy, postmenopausal women. Methods Intramuscular electrodes were inserted into each segment of the GMed and GMin in 10 healthy, postmenopausal women. Participants completed 7 gluteal rehabilitation exercises, and average normalized muscle activity was used to rank the exercises from highest to lowest. Results The isometric standing hip hitch with contralateral hip swing was the highest-ranked exercise for all muscle segments except the anterior GMin, where it was ranked second. The highest-ranked dynamic exercise for all muscle segments was the dip test. Conclusion The hip hitch and its variations maximally activate the GMed and GMin muscle segments, and may be useful in hip muscle rehabilitation in postmenopausal women. J Orthop Sports Phys Ther 2017;47(12):914-922. Epub 15 Oct 2017. doi:10.2519/jospt.2017.7229.

Hip Abductor Strengthening Improves Physical Function Following Total Knee Replacement: One-Year Follow-Up of a Randomized Pilot Study

BACKGROUND

Total knee replacement (TKR) is the commonest surgical procedure for patients with severe pain and impaired physical function following end stage knee osteoarthritis. The hip abductors are well renowned in stabilization of the trunk and hip during walking, maintaining the lower limb position, and transferring the forces from the lower limbs to the pelvis.

OBJECTIVE

To assess the efficacy of hip abductor strengthening exercise on functional outcome using performance based outcome measures following total knee replacement.

METHODS

An observer blinded randomized pilot trial design was conducted at Manipal hospital, Bangalore, India. Participants designated for elective TKR were randomized to experimental group hip abductor strengthening along with standard rehabilitation (n=10) or control group standard rehabilitation alone (n=10). Participants followed for one year to assess physical function using performance based outcomes, such as timed up and go test, single leg stance test, six minute walk test, knee extensor strength and hip abductor strength.

RESULT

Eighteen participants with a mean age of 63.1 ± 5.5 years (8 Males and 10 Females) completed the study. Improvement in hip abduction strength, single leg stand test was superior in hip abductor strengthening group at 3 months and 1 year when compared to standard rehabilitation alone.

CONCLUSION

Hip abductor strengthening showed superior improvements in single leg stance test and six minute walk test. Hip abductor strengthening exercises has the potential to improve physical function following total knee replacement.