The beneficial effects of eccentric exercise in the management of lateral elbow tendinopathy: a systematic review and meta-analysis

Key points

1. 01Adding eccentric exercise to adjuvant therapy produced a significant improvement in pain (SMD -0.63) and muscle strength (SMD 1.05) vs adjuvant therapy alone.
2. 02Eccentric exercise reduced pain more than concentric or isotonic exercise (SMD -0.30), but did not significantly outperform them on strength or function.
3. 03Exercise devices varied widely across studies: rubber bars, elastic bands, buckets, and isokinetic machines were all used.
4. 04Only 6 RCTs with 429 participants met strict inclusion criteria, limiting confidence in the pooled estimates.
5. 05No serious adverse events or delayed-onset muscle soreness were reported in any included study.

How it was conducted

Design

Systematic review and meta-analysis of randomized controlled trials

Databases

PubMed (MEDLINE), EMBASE, Cochrane Central Register of Controlled Trials, searches up to May 2021

Included studies

6 RCTs, 429 participants total

Participants

Adults with lateral elbow tendinopathy; mean age range 38 to 51 years

Primary outcomes

Pain intensity (VAS), muscle strength (grip or extensor), and function (DASH questionnaire)

Analysis

Fixed-effect model; effect sizes expressed as standardized mean difference (SMD) with 95% CI; heterogeneity by I2

What they found

• Add-on eccentric exercise vs adjuvant therapy alone: VAS pain improvement SMD -0.63 (95% CI -0.90 to -0.36), statistically significant.
• Add-on eccentric exercise vs adjuvant therapy alone: muscle strength improvement SMD 1.05 (95% CI 0.78 to 1.33), statistically significant.
• Eccentric vs concentric/isotonic exercise: VAS pain improvement SMD -0.30 (95% CI -0.58 to -0.02), statistically significant.
• Eccentric vs concentric/isotonic exercise: muscle strength SMD -0.09 (95% CI -0.38 to 0.20), no significant difference.
• Eccentric vs concentric/isotonic exercise: DASH function SMD -0.08 (95% CI -0.35 to 0.20), no significant difference.
• Participant numbers per study ranged from 21 to 120; intervention duration ranged from 2 weeks to 3 months.

Limitations

• Only 6 studies with 429 participants were available, making pooled estimates fragile.
• Exercise protocols differed substantially across studies in device, intensity, frequency, and supervision, preventing subgroup or optimal-protocol analysis.
• Two studies had high risk of selection bias due to non-random allocation methods; allocation concealment was unclear in all six studies.
• Exercise intensity relative to pain and long-term follow-up were poorly reported, leaving questions about safety thresholds and durability of benefit unanswered.

Why it matters

For patients

Eccentric exercise added to your usual physiotherapy is likely to reduce elbow pain and improve strength, and appears safe with no serious side effects reported.

For clinicians

Current limited evidence supports prescribing eccentric exercise as an adjunct to standard conservative care; it also offers modest pain advantages over concentric or isotonic programmes, though the optimal protocol remains undefined.

For readers

This is the first meta-analysis isolating eccentric exercise effects in lateral elbow tendinopathy, and while results are encouraging, the small evidence base and heterogeneous protocols mean conclusions should be treated as provisional.