Does neuromuscular electrical stimulation of the leg muscles improve structure and function in adults with kidney failure undergoing dialysis? A comprehensive review published up to mid-2025 reveals that while this technique delivers small electrical impulses to induce muscle contractions without voluntary exercise, current evidence remains very uncertain regarding its impact on daily activities, functional independence, and overall mortality.
Understanding Muscle Wasting in End-Stage Renal Disease
Adults suffering from kidney failure—a condition where the kidneys no longer function well enough to keep a person alive—frequently experience muscle weakness and loss of strength. This decline stems from reduced physical activity and the effects of kidney disease. While exercise can help, many adults on dialysis struggle to participate due to fatigue, illness, or limited time. To bypass this barrier, researchers have investigated neuromuscular electrical stimulation (NMES), a technique that applies small electrical impulses through the skin to trigger contractions in targeted muscle groups, specifically the legs.
Clinical Evidence and Trial Landscape
A systematic evaluation synthesized data from 12 studies encompassing 348 adult participants receiving haemodialysis across eight countries. These trials were predominantly small-scale, with intervention durations ranging between four and 20 weeks. Of the enrolled cohort, outcome data for 299 participants were available for analysis. Notably, none of the evaluated trials included patients undergoing peritoneal dialysis. Furthermore, substantial variance across the examined NMES programmes prevents definitive conclusions regarding which treatment programme works best.
When assessing functional independence and everyday activities, only a single small study evaluated this parameter, leaving the overall evidence base very uncertain. Cardiorespiratory metrics fared similarly: data from four trials indicated that NMES may result in little to no difference in blood pressure, while two studies found it may make little to no difference to resting heart rate. With regard to safety endpoints, one participant receiving usual care died during a trial period, but the evidence is very uncertain, so it is not known whether NMES affects the risk of death. Crucially, none of the reviewed literature measured or reported outcomes such as fatigue, pain, infection, or problems with dialysis access.
| Clinical Parameter | Number of Studies | Total Evaluated Participants | Current Evidence Consensus |
|---|---|---|---|
| Daily Activities & Independence | 1 study | Low sample size | Very uncertain; insufficient data |
| Blood Pressure Impact | 4 studies | Moderate | Little to no difference observed |
| Resting Heart Rate | 2 studies | Small | Little to no difference observed |
| Risk of Mortality | 1 study (event recorded) | Low sample size | Very uncertain; inconclusive |
| Fatigue, Pain, Infection, Access Issues | 0 studies | None reported | Not measured or reported in current literature |
Funding, Bias Transparency, and Epidemiological Context
In Plain English: The Clinical Takeaway
- Passive Muscle Activation: NMES uses small electrical impulses to make leg muscles contract without requiring active, voluntary exercise from the patient.
- Uncertain Benefits: Current clinical studies are too small and varied to prove whether this technology genuinely improves daily physical independence or survival rates.
- Missing Safety Metrics: Crucial everyday concerns for dialysis patients—such as dialysis access safety, pain levels, and exhaustion—were not reported by existing research.
Conclusion and Future Trajectory
While neuromuscular electrical stimulation offers a mechanism to combat muscle weakness and loss of strength in dialysis cohorts, robust empirical validation remains absent.
References
- Cochrane Database of Systematic Reviews – Neuromuscular electrical stimulation for adults with kidney failure on dialysis (Search current to June 2025).
