Hip abductor strength–based exercise therapy in treating women with moderate-to-severe knee osteoarthritis: a randomized controlled trial

Cut-off values of preoperative knee extensor strength and hip abductor strength for predicting good walking ability after total knee arthroplasty

INTRODUCTION

Total knee arthroplasty (TKA) reduces pain and improves physical function; however, not all patients have successful outcomes after surgery. To identify these patients would be critical information for improving rehabilitation programs. The purpose of this study was to clarify the cut-off values of lower extremity muscle strength for predicting postoperative good walking ability.

MATERIALS AND METHODS

Timed Up and Go test of 105 patients was measured at 6 months postoperatively, and participants were divided into good (< 9.1 s) and poor (≥ 9.1 s) walking ability. Both sides of knee extensor strength (KES) and hip abductor strength (HAS) were measured using hand-held dynamometer preoperatively. Receiver operating characteristic (ROC) curve analysis was used to identify cut-off values for classifying the participants into the two groups.

RESULTS

Of the 105 patients, 54 were allocated in the poor walking ability group, whereas 51 were allocated in the good walking ability group. KES and HAS were significantly greater in the good walking ability group than in the poor walking ability group. ROC curve analysis revealed that the cut-off value for KES was 0.79 Nm/kg (area under the curve (AUC) 0.68; sensitivity 64.7%; specificity 68.5%) on the involved side and 0.86 Nm/kg (AUC 0.73; sensitivity 84.6%; specificity 55.6%) on the uninvolved side, and for HAS was 0.57 Nm/kg (AUC 0.71; sensitivity 60.8%; specificity 71.7%) on the involved side and 0.61 Nm/kg (AUC 0.76; sensitivity 66.7%; specificity 77.4%) on the uninvolved side.

CONCLUSION

The cut-off values of preoperative KES and HAS for predicting good walking ability after TKA are 0.79 Nm/kg on the involved side and 0.86 Nm/kg on the uninvolved side, and 0.57 Nm/kg on the involved side and 0.61 Nm/kg on the uninvolved side, respectively. We should provide enhanced pre- and post-operative rehabilitation programs for patients with muscle strength lower than these values.

Effect of adding hip exercises to general rehabilitation treatment of knee osteoarthritis on patients' physical functions: a randomized clinical trial

BACKGROUND

Hip adductor and abductor strength were both reduced in KOA patients. But to date, most of the researches have only focused on quadriceps combined with hip abductor strengthening versus quadriceps strengthening.

OBJECTIVE

The aim of the study is to evaluate the effect of adding hip abductor and adductor strengthening to quadriceps strengthening on lower limb strength, knee pain and physical function in patients with medial compartmental knee osteoarthritis.

METHODS

In this study, 42 participants, were randomly divided into two groups: the general treatment group (GT group) and the added-hip-exercise group (AH group). All participants were given a general rehabilitation treatment. The AH group performed hip abductor and adductor strengthening in addition to the general rehabilitation treatment. Knee and hip muscle strength, Five Times Sit-to-Stand Test (FTSST), the Timed Up and Go Test (TUGT), Numerical Rating Scale (NRS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were assessed at baseline and 6 weeks. A two-sided 2-sample unpaired t test was performed to compare the difference in mean change scores between AH and GT groups.

RESULTS

Finally, 36 participants completed the study: both groups consist of 18 participants. In the per-protocol analysis, the AH group had a greater improvement in knee extension strength (mean changes, 7.84 versus 36.48; P < 0.001) and hip abduction strength (mean changes, 5.05 versus 26.62; P = 0.001) than the control group. Similarly, the AH group had a greater improvement in the FTSST time (mean changes, 0.40 s versus 3.57 s; P < 0.001) and the TUFT time (mean changes, 0.18 s versus 1.67 s; P = 0.002) than the GH group. No statistical difference was found in the change of WOMAC pain scores and NRS between the 2 groups.

CONCLUSIONS

Older adults with knee OA in the AH group had superior muscle strength, symptoms and daily activity performance at the 6th week than those in the GT group. And adding hip exercises could expedite improvement of pain at the 2th week, but not at the 6th week.

TRIAL REGISTRATION

Clinical trial registration numbers and date of registration: ChiCTR-IOR-16009124, Registered 30 August 2016.

Gluteal Muscle Forces during Hip-Focused Injury Prevention and Rehabilitation Exercises

PURPOSE

This study aimed to compare and rank gluteal muscle forces in eight hip-focused exercises performed with and without external resistance and describe the underlying fiber lengths, velocities, and muscle activations.

METHODS

Motion capture, ground reaction forces, and electromyography (EMG) were used as input to an EMG-informed neuromusculoskeletal model to estimate gluteus maximus, medius, and minimus muscle forces. Participants were 14 female footballers (18-32 yr old) with at least 3 months of lower limb strength training experience. Each participant performed eight hip-focused exercises (single-leg squat, split squat, single-leg Romanian deadlift [RDL], single-leg hip thrust, banded side step, hip hike, side plank, and side-lying leg raise) with and without 12 repetition maximum (RM) resistance. For each muscle, exercises were ranked by peak muscle force, and k-means clustering separated exercises into four tiers.

RESULTS

The tier 1 exercises for gluteus maximus were loaded split squat (95% confidence interval [CI] = 495-688 N), loaded single-leg RDL (95% CI = 500-655 N), and loaded single-leg hip thrust (95% CI = 505-640 N). The tier 1 exercises for gluteus medius were body weight side plank (95% CI = 338-483 N), loaded single-leg squat (95% CI = 278-422 N), and loaded single-leg RDL (95% CI = 283-405 N). The tier 1 exercises for gluteus minimus were loaded single-leg RDL (95% CI = 267-389 N) and body weight side plank (95% CI = 272-382 N). Peak gluteal muscle forces increased by 28-150 N when exercises were performed with 12RM external resistance compared with body weight only. Peak muscle force coincided with maximum fiber length for most exercises.

CONCLUSIONS

Gluteal muscle forces were exercise specific, and peak muscle forces increased by varying amounts when adding a 12RM external resistance. These findings may inform exercise selection by facilitating the targeting of individual gluteal muscles and optimization of mechanical loads to match performance, injury prevention, or rehabilitation training goals.

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.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05557-6.

Osteoarthritis year in review 2020: rehabilitation and outcomes

OBJECTIVE

Systematically review and synthesize guidelines, systematic reviews, or randomized controlled trials (RCTs) published between April 1, 2019 and April 30, 2020 which evaluated or made recommendations for rehabilitation of persons with osteoarthritis.

DESIGN

Five electronic databases (Medline, EMBASE, Cochrane CENTRAL, CINHAL, Web of Science) were searched with a comprehensive search strategy. Guidelines for rehabilitation of persons with osteoarthritis, and systematic reviews and RCTs evaluating osteoarthritis rehabilitation that included at least one patient-reported outcome measure and/or clinical test of function were included. Two authors independently screened records and assessed methodological quality using the AGREE-II (guidelines), AMSTAR-2 (systematic reviews) or PEDro scale (RCTs). Data were extracted to summarize included records and a narrative synthesis of findings related to core recommended osteoarthritis rehabilitation treatments performed.

RESULTS

Of 2,479 potential records, 253 records were reviewed. Two guidelines, 18 systematic reviews and 38 RCTs were included. 84% (n = 49) of included records related to knee osteoarthritis, 13% (n = 8) to hip, 10% (n = 6) to hand, 3% (n = 2) to mixed, and 1% (n = 1) to foot osteoarthritis. Exercise-therapy, methods to deliver exercise-therapy remotely, and approaches to facilitate exercise-therapy behaviour change were the most commonly evaluated interventions (n = 27). 94% of systematic reviews and 63% of RCTs rated high-quality.

CONCLUSIONS

Osteoarthritis rehabilitation research continues to focus on knee osteoarthritis and exercise-based interventions. Emerging topics include rehabilitation of comorbid populations, exercise behaviour change and technology supports. A better understanding of rehabilitation of osteoarthritis in joints other than the knee, and methods to determine and promote ideal exercise-therapy prescription are needed.

Effects of Muscle Strengthening around the Hip on Pain, Physical Function, and Gait in Elderly Patients with Total Knee Arthroplasty: A Randomized Controlled Trial

Background: Functional limitations may still remain even after a patient completes a traditional quadriceps-based rehabilitative program after total knee arthroplasty. Based on studies reporting that patients with knee osteoarthritis have muscle weakness around the hip joint after total knee arthroplasty, we investigated whether strengthening the hip muscles can reduce pain and improve the physical function and gait of patients who underwent total knee arthroplasty. Methods: Patients were randomly divided into three groups: hip, quadriceps, and control. The hip group (n = 19) completed an extensor, adductor, and external muscle strengthening exercise program. The quadriceps group (n = 20) completed a quadriceps strengthening exercise program. The control group (n = 16) completed an active range of motion exercises. Therapy was conducted thrice weekly for 12 weeks. Pain and function items from the Western Ontario and McMaster Universities Osteoarthritis Index, Alternate Step Test, Five Times Sit to Stand Test, and Single Leg Stance Test were performed to assess pain and physical function. In the gait analysis, stride, single-stance (%), double-stance (%), and gait speed were measured. Data were collected at baseline and at 4, 8, and 12 weeks after the intervention. Results: The hip group showed more significant improvements in pain and performance on the Alternate Step Test and Single Leg Stance Test than the quadriceps and control groups. In the gait analysis, the hip group showed the largest improvements in single stance and double stance. Conclusions: In conclusion, a 12-week hip muscle strengthening exercise program effectively improves the physical function and gait of patients who have undergone total knee arthroplasty.