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

Effectiveness of neuromuscular electrical stimulation training combined with exercise on patient-reported outcomes measures in people with knee osteoarthritis: A systematic review and meta-analysis

OBJECTIVE

This study examined the effectiveness of neuromuscular electrical stimulation (NMES) added to the exercise or superimposed on voluntary contractions on patient-reported outcomes measures (PROMs) in people with knee osteoarthritis (OA).

METHODS

This systematic review was described according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomized controlled trials (RCTs) were obtained from a systematic literature search in five electronic databases (PubMed, PEDro, LILACS, EMBASE, and SPORTDiscus) in April 2022. We described the effects of intervention according to each PROMs (scores for Pain; Self-reported functional ability; Symptoms (hear clicking, swelling, catching, restricted range of motion, and stiffness); Daily living function; Sports function; and Quality of life) and used a random-effect model to examine the impact of NMES plus exercise on pain compared with exercise in people with knee OA.

RESULTS

Six RCTs (n = 367) were included. In the qualitative synthesis, the systematic literature analysis showed improvement in pain after NMES plus exercise compared with exercise alone in three studies. The other three studies revealed no difference between groups in pain, although similar improvement after treatments. In the meta-analysis, NMES at a specific joint angle combined with exercise was not superior to exercise alone in pain management (standardized mean difference = -0.33, 95% CI = -1.05 to 0.39, p = 0.37). There was no additional effect of NMES on exercise on self-reported functional ability, stiffness, and physical function compared with exercise alone. In only one study, symptoms, activities of daily living, sports function, and quality of life improved after whole-body electrostimulation combined with exercise.

CONCLUSION

This review found insufficient evidence for the effectiveness of NMES combined with exercise in treating knee OA considering PROMs. While pain relief was observed in some studies, more high-quality clinical trials are needed to support the use of NMES added to the exercise in clinical practice. Electrical stimulation in a whole-body configuration combined with exercise shows promise as an alternative treatment option.

Mechanisms of action of therapeutic exercise for knee and hip OA remain a black box phenomenon: an individual patient data mediation study with the OA Trial Bank

OBJECTIVES

To evaluate mediating factors for the effect of therapeutic exercise on pain and physical function in people with knee/hip osteoarthritis (OA).

METHODS

For Subgrouping and TargetEd Exercise pRogrammes for knee and hip OsteoArthritis (STEER OA), individual participant data (IPD) were sought from all published randomised controlled trials (RCTs) comparing therapeutic exercise to non-exercise controls in people with knee/hip OA. Using the Counterfactual framework, the effect of the exercise intervention and the percentage mediated through each potential mediator (muscle strength, proprioception and range of motion (ROM)) for knee OA and muscle strength for hip OA were determined.

RESULTS

Data from 12 of 31 RCTs of STEER OA (1407 participants) were available. Within the IPD data sets, there were generally statistically significant effects from therapeutic exercise for pain and physical function in comparison to non-exercise controls. Of all potential mediators, only the change in knee extension strength was statistically and significantly associated with the change in pain in knee OA (β -0.03 (95% CI -0.05 to -0.01), 2.3% mediated) and with physical function in knee OA (β -0.02 (95% CI -0.04 to -0.00), 2.0% mediated) and hip OA (β -0.03 (95% CI -0.07 to -0.00), no mediation).

CONCLUSIONS

This first IPD mediation analysis of this scale revealed that in people with knee OA, knee extension strength only mediated ±2% of the effect of therapeutic exercise on pain and physical function. ROM and proprioception did not mediate changes in outcomes, nor did knee extension strength in people with hip OA. As 98% of the effectiveness of therapeutic exercise compared with non-exercise controls remains unexplained, more needs to be done to understand the underlying mechanisms of actions.