What is the evidence for adjunctive electrical stimulation (ES) compared to standard physical therapy alone in enhancing muscle strength, lower limb function, and self-reported recovery in patients following anterior cruciate ligament reconstruction (ACLR)?
AMSTAR Rating
Summary
Patient Population:
15 randomized controlled trials (RCTs) met eligibility criteria, encompassing a total sample size of n = 1,583 patients (aged 15 to 50 years, average 32.3) following primary anterior cruciate ligament reconstruction (ACLR). Interventions were initiated early (typically 1 to 5 days postoperatively) across general and athletic populations.
Intervention:
Standard physical therapy augmented by therapeutic electrical stimulation (ES). Specific modalities evaluated included neuromuscular electrical stimulation (NMES) for quadriceps muscle re-education/hypertrophy and transcutaneous electrical nerve stimulation (TENS) for pain modulation. Treatment protocols varied from 10 to 60 minutes per session, 3 to 7 times weekly, for 2 to 12 weeks postoperatively.
Comparison:
Standard postoperative physical therapy alone (conventional rehabilitation exercises without adjunctive electrical stimulation).
Outcome:
Random–effects meta-analysis demonstrated that adjunctive ES significantly improved comprehensive lower limb functional recovery across multiple clinical metrics compared to control groups.
Significant improvements were observed in muscle strength (Standardized Mean Difference [SMD] = 0.55; 95% CI, 0.14 to 0.95; p = 0.008), knee range of motion (SMD = 1.10; 95% CI, 0.40 to 1.79; p = 0.002), self-reported Lysholm functional scale scores (SMD = 1.05; 95% CI, 0.36 to 1.73; p = 0.003), and visual analogue scale (VAS) pain reduction (SMD = 0.87; 95% CI, 0.38 to 1.37; p = 0.0006).
However, no statistically significant difference was observed between groups regarding thigh limb circumference (SMD = 0.61; 95% CI, -0.78 to 2.00; p = 0.39). Evidence certainty was rated as moderate across all outcomes, and zero adverse events were reported.
Guideline Recommendations
| Source | Recommendation |
|---|---|
| ACPG guideline for ACLR, 2023 | Supports use in early-stage of rehabilitation |
| AAOS, 2022 | Optional adjunct |
Outcomes Assessed
- Benefit
- Harm
- Inconclusive
E-stim v. conventional rehabilitation
Muscle Strength
Knee ROM
Thigh Limb Circumference
Function scales
Pain reduction
Relevant Clinical Info
Feil S, Newell J, Minogue C, Paolini JA, Rosenblaum B. The effectiveness of supplementing a standard rehabilitation program with superimposed neuromuscular electrical stimulation after anterior cruciate ligament reconstruction: a prospective, randomized, single-blind study. Am J Sports Med. 2011;39(6):1238-1247. doi: 10.1177/0363546510396321.
Feil et al. (2011) was a prospective, single-blind RCT included in the meta-analysis, evaluating 89 patients undergoing ACL reconstruction. Participants were randomized to receive either standard rehabilitation alone or standard rehabilitation supplemented with superimposed NMES starting in the early postoperative phase. The trial demonstrated that adding NMES produced significantly greater isometric quadriceps muscle strength, improved Lysholm functional knee scores, and accelerated return-to-function milestones compared to standard physical therapy alone, establishing a key primary clinical anchor for early electrical stimulation in ACL recovery.
Participant Information
The sample size was 1583
Mean age of 32.3 years.
There were 15 studies used.
