Effect of gender on strength gains after isometric exercise coupled with electromyographic biofeedback in knee osteoarthritis: A preliminary study

Recovery of Quadriceps Strength and Knee Function Using Adjuvant EMG-BF After Primary ACL Reconstruction

Introduction: Immobility and limited usage of operated limbs lead to weakness and atrophy of the muscle after anterior cruciate ligament (ACL) reconstruction. However, training programs for preventing biomechanical risk factors such as lower limb alignment and increased muscular contraction are very limited. Thus, the current study was carried out to evaluate the recovery of quadriceps muscle strength and the improvement of knee function using adjuvant electromyographic biofeedback (EMG-BF) after ACL reconstruction. Methods: This prospective randomized controlled trial was conducted among 40 patients (20=EMG-BF group, 20=Control group) with ACL reconstruction, who were referred to Akhtar Hospital from 2021 to 2022. In the EMG-BF group, EMG BFB was added to the standard rehabilitation protocol, and in the control group, the standard rehabilitation protocol with full postoperative weight-bearing, knee brace (zero degree of extension, 90 degrees of flexion), and electrical stimulation with maximal voluntary isometric knee extension was performed. Each group was intervened for 4 weeks and three sessions of 30 minutes per week. It should be noted that each patient participated in 16 outpatient physiotherapy sessions after surgery. Nicholas Hand-Held Dynamometer (HHD) was used for measuring quadriceps strength, and Knee Outcome Survey-Activities of Daily Living (KOS-ADLs) and Knee Outcome Survey Sports Activities Scale (KOS-SAS) questionnaires were used for assessing the knee function. Results: Four weeks after the treatment, the EMG-BF group showed a significant increase in quadriceps strength (P=0.0001). Quadriceps strength had a significant difference before and after 4 weeks of intervention (P=0.0001), but in the control group, no significant difference was observed (P=0.368). The EMG-BF group had a significant increase in KOS-ADLs and KOS-SAS scores after 4 weeks of intervention (P=0.0001). Conclusion: In our study, isometric strengthening of quadriceps with adjuvant EMG-BF significantly increased the strength of quadriceps and knee function during 4 weeks. EMG-BF is a low risk, low cost, and less invasive intervention and has high safety and adjustment ability. It is a valuable adjuvant method for achieving better functional recovery in a shorter time.

Efficacy of Patellar Taping and Electromyographic Biofeedback Training at Various Knee Angles on Quadriceps Strength and Functional Performance in Young Adult Male Athletes with Patellofemoral Pain Syndrome: A Randomized Controlled Trial

Background

The severity of the articular lesion is the single most essential element in investigating the extent of flexion that is required for activities. However, a prior study found no differences in muscle strength gains of quadriceps muscles at different knee angles in people with patellofemoral pain syndrome (PFPS).

Objective

The effects of patellar taping and electromyographic biofeedback (EMG-BF)-guided isometric quadriceps strengthening at different knee angles (e.g., 30°, 60°, and 90° of knee flexion) on quadriceps strength and functional performance in people with PFPS were compared in this single-blind randomized controlled parallel trial.

Methods

Sixty adult male athletes with PFPS (age: 26.9 ± 1.4 years) were randomly divided into two groups. The experimental group (n = 30) received patellar taping and EMG-BF-guided isometric contraction exercise at 30°, 60°, and 90° angles, and the control group (n = 30) received sham patellar taping without EMG-BF-guided exercises for six weeks. Pain intensity, knee function, muscle strength, and the single-leg triple hop (SLTH) test were assessed.

Results

The pain intensity and SLTH scores between the groups were significantly different at the end of the trial (p ≤ 0.001). The EMG-BF and control groups had mean pain scores of 1.3 (0.8) and 4.5 (0.8), respectively. The EMG-BF and control groups had mean functional scores of 80.4 (5.1) and 69.1 (6.1), respectively. The mean SLTH score for the EMG-BF group was 540.7 (51.2) and for the control group it was 509.4 (49.8) after the trial. Quadriceps muscle strength was significantly higher in those who performed quadriceps strength training at 60° of knee flexion after six weeks than in those who performed strength training at 30° or 90° of knee flexion.

Conclusion

The findings indicated that individuals who trained their quadriceps at a 60° knee angle had significantly stronger quadriceps muscles than individuals who trained at 30° or 90° of knee flexion. Trial Registration. This trial is registered at Clinical Trials.gov under the identifier NCT05055284.

Benefits and Mechanisms of Exercise Training for Knee Osteoarthritis

Knee osteoarthritis is a chronic degenerative disease. Cartilage and subchondral bone degeneration, as well as synovitis, are the main pathological changes associated with knee osteoarthritis. Mechanical overload, inflammation, metabolic factors, hormonal changes, and aging play a vital role in aggravating the progression of knee osteoarthritis. The main treatments for knee osteoarthritis include pharmacotherapy, physiotherapy, and surgery. However, pharmacotherapy has many side effects, and surgery is only suitable for patients with end-stage knee osteoarthritis. Exercise training, as a complementary and adjunctive physiotherapy, can prevent cartilage degeneration, inhibit inflammation, and prevent loss of the subchondral bone and metaphyseal bone trabeculae. Increasing evidence indicates that exercise training can improve pain, stiffness, joint dysfunction, and muscle weakness in patients with knee osteoarthritis. There are several exercise trainings options for the treatment of knee osteoarthritis, including aerobic exercise, strength training, neuromuscular exercise, balance training, proprioception training, aquatic exercise, and traditional exercise. For Knee osteoarthritis (KOA) experimental animals, those exercise trainings can reduce inflammation, delay cartilage and bone degeneration, change tendon, and muscle structure. In this review, we summarize the main symptoms of knee osteoarthritis, the mechanisms of exercise training, and the therapeutic effects of different exercise training methods on patients with knee osteoarthritis. We hope this review will allow patients in different situations to receive appropriate exercise therapy for knee osteoarthritis, and provide a reference for further research and clinical application of exercise training for knee osteoarthritis.

Efficacy of Electromyographic-Biofeedback Supplementation Training with Patellar Taping on Quadriceps Strengthening in Patellofemoral Pain Syndrome among Young Adult Male Athletes

This study compares the effects of electromyographic-biofeedback (EMG-BF)-guided isometric quadriceps strengthening with patellar taping and isometric exercise alone in patellofemoral pain syndrome (PFPS) among young adult male athletes. Sixty young adult male athletes with PFPS participated in the study. Participants were randomly divided into two groups: (1) EMG-BF-guided isometric exercise training with patellar taping (experimental group, n = 30), and (2) sham EMG-BF training with an isometric exercise program (control group, n = 30). Participants conducted their respective exercise programs for five days per week across four weeks. Study outcomes were pain (measured by the visual analog scale), functional disability (measured by the Kujala Anterior Knee Pain scale), and quadriceps strength (measured by an ISOMOVE dynamometer). Measurements were taken at baseline, Week 2, Week 4, and during a follow-up at Week 6. The experimental group demonstrated significantly lower VAS score at Weeks 2 and 4 compared to that of the control group (p = 0.008 and 0.0005, respectively). The score remained significantly lower at the Week 6 follow-up compared to the control group (p = 0.0005). There were no differences in knee function at Weeks 2 and 4 between the two groups (p = 0.086 and 0.171, respectively); however, the experimental group showed significantly better knee function at Week 6 compared to the control group (p = 0.002). There were no differences in quadriceps strength at Week 2 between the two groups (p = 0.259); however, the experimental group demonstrated significantly higher quadriceps strength at Weeks 4 and 6 compared to the control group (p = 0.0008). Four weeks of EMG-BF supplementation training with patellar taping demonstrated significant improvements in pain intensity, functional disability, and quadriceps muscle strength in young adult male athletes with PFPS.

The efficacy of electromyographic biofeedback on pain, function, and maximal thickness of vastus medialis oblique muscle in patients with knee osteoarthritis: a randomized clinical trial

INTRODUCTION

The aim of this survey was to examine the effect of adding electromyographic biofeedback (EMGBF) to isometric exercise, on pain, function, thickness, and maximal electrical activity in isometric contraction of the vastus medialis oblique (VMO) muscle in patients with knee osteoarthritis (OA).

METHODS

In this clinical trial, 46 patients with a diagnosis of knee OA were recruited and assigned to two groups. The case group consisted of 23 patients with EMGBF-associated exercise, and the control group was made up of 23 patients with only isometric exercise. Data were gathered via visual analog scale (VAS) score, the Persian version of the Western Ontario and McMaster Universities Osteoarthritis Index and Lequesne questionnaires, ultrasonography of the VMO, and surface electromyography of this muscle at baseline and at the end of the study. Variables were compared before and after the exercise program in each group and between the two groups.

RESULTS

At the end of the study, there were no significant differences between the two groups regarding measured variables. Only the VAS score was significantly less in the case group. Although all assessed parameters, except for VMO muscle thickness, were found to be improved significantly in each group, the degree of change was not significantly different between the two groups, except for VAS score. VMO muscle thickness did not change significantly after exercise therapy in either of the groups.

CONCLUSION

Isometric exercises accompanied by EMGBF and the same exercises without biofeedback for 2 months both led to significant improvements in pain and function of patients with knee OA. Real EMGBF was not superior to exercise without biofeedback in any of the measured variables, except for VAS score.

Effects of isometric exercise using biofeedback on maximum voluntary isometric contraction, pain, and muscle thickness in patients with knee osteoarthritis

[Purpose] The purpose of our study was to investigate the effects of isometric exercises using electromyographic biofeedback (EMGBF) and ultrasound biofeedback (USBF) on maximum voluntary isometric contraction (MVIC), pain assessed by the Visual Analogue Scale (VAS), and vastus medialis oblique (VMO) thickness in patients with knee osteoarthritis (OA). [Subjects and Methods] Thirty females over 65 years of age who had been diagnosed with knee osteoarthritis were recruited and randomly assigned to three groups, each comprising of 10 subjects. The Subjects in the EMGBF training and USBF training groups were trained with the corresponding physical training exercise program targeting the vastus medialis oblique, whereas the subjects in the control group were treated with conventional physical therapies, such as a hot pack, ultrasound, and transcutaneous electrical nerve stimulation. Subjects in each group were trained or treated for 20 min, 3 times a week for 8 weeks. [Results] The MVIC in the EMGBF and USBF training groups was significantly increased compared with that in the control group, and the VAS score (for measurement of pain) in the EMGBF and USBF training groups was significantly decreased compared with that in the control group. Only the EMGBF training group showed a significantly increased VMO thickness compared with before training. [Conclusion] These results suggest that USBF training is similar to EMGBF training in terms of its effectiveness and is helpful for treating patients with knee OA.