Shoulder Strength · Stage 03
Rebuilding a shoulder that feels weak, not just pain-free.
"Can I still lift weights with shoulder pain?" "Weak shoulder after rotator cuff injury." "Why does my shoulder still feel unstable months later?" If a search like that brought you here: this page covers why rotator cuff and scapular strength are central to lasting shoulder recovery, what the current evidence supports for training methods, and where the benchmarks used to guide return-to-sport actually come from — including where that evidence is thinner than you'd expect.
Assessment + treatment from session one · $750 MXN · Zona Rio, Tijuana.
By Leonardo Machado, LFT · Licensed Physiotherapist · issuing institution name pending publication
Pain often settles before shoulder strength has actually been rebuilt — and that gap is where most preventable setbacks happen, particularly in overhead and combat-sports athletes. A shoulder that no longer hurts at rest but has never rebuilt rotator cuff and scapular capacity is not a recovered shoulder. It's a shoulder that feels fine reaching for a coffee cup and gets exposed the moment it's asked to press overhead, throw, or absorb a joint-lock in BJJ.
This is educational content, not a personalized loading program. What load you should be using, how quickly to progress, and which exercises are appropriate depend on assessment findings, your stage of recovery, and — for post-surgical patients — your surgeon's clearance. If you're managing a surgical recovery, coordinate strength progression with your treating surgeon and clinician.
Why it matters
Active exercise builds real strength — passive treatment doesn't.
A 2026 systematic review with meta-analysis pooling 28 studies and 1,429 patients with rotator-cuff-related shoulder pain found that active exercise and strength training produced small-to-moderate but genuine strength gains across external rotation, abduction, scaption, internal rotation, and flexion. Interventions that did not include active exercise showed no meaningful strength effect at all. Programs of six to twelve weeks were generally sufficient — extending beyond that window did not clearly add more benefit. The current, most recent clinical practice guideline (2025) reflects the same conclusion: active, progressive rehabilitation exercise should be the first-line treatment for rotator cuff-related pain and disability, ahead of passive modalities.
Benchmarks
The ER:IR ratio — a useful reference range, not an exact cutoff.
One benchmark used in shoulder assessment is the ratio between external rotation (ER) and internal rotation (IR) strength — since internal rotators are naturally stronger, a commonly cited target range is roughly 66% on isokinetic testing or 75–100% on isometric testing, depending on test position. A 2025 cohort study of 296 amateur overhead athletes found an isometric ER/IR ratio below 0.75 was the most prevalent strength-related risk factor for overuse shoulder injury in both men and women.
That said, the picture across the wider research isn't as clean as a single number suggests. A systematic review of isokinetic dynamometry studies found genuinely conflicting results when pooling the evidence — the "low ratio predicts injury" signal held up better in prospective cohort studies than in cross-sectional ones, and testing protocols varied enough between studies to limit how precisely any one cutoff can be applied. Here, the ER:IR ratio is used as one useful reference point in a broader assessment — not a single number that, on its own, clears or flags a shoulder.
How it's built
Training methods — what the current evidence supports.
EMG studies consistently show underuse of the serratus anterior and lower/mid trapezius, paired with overuse of the upper trapezius, in people with subacromial pain. Targeted scapular stabilization exercise improves scapulothoracic movement patterns and reduces pain — one of the more consistently supported pieces of shoulder strength rehabilitation.
Unlike the knee, where open- and closed-chain sequencing after ACL reconstruction is backed by substantial randomized trial evidence, the shoulder equivalent is mostly biomechanical rationale rather than head-to-head trials. Closed-chain work is theorized to favor early scapulohumeral co-contraction and rotator-cuff force-couple stability, with open-chain work introduced for more isolated, progressive loading later — a clinically reasoned progression, not an RCT-backed protocol the way it is for the knee.
Isometric-first pain modulation, progressing to isotonic or heavy-slow-resistance strengthening, then functional and plyometric loading, is a reasonable framework pulled from broader tendinopathy principles and the 2025 guideline's emphasis on active, progressive loading. This is described honestly as an extrapolated framework — direct randomized trial support for isometric-first sequencing specific to the rotator cuff is limited, mostly a single small isometric-versus-cryotherapy trial, unlike the more established lower-limb tendinopathy evidence it's drawn from.
Evidence
What the evidence says.
A 2026 meta-analysis of 28 studies (1,429 patients) found active exercise/strength training produced genuine small-to-moderate strength gains across multiple movement directions for rotator-cuff-related shoulder pain; interventions without active exercise showed no strength effect (Zhang B, Raguzzi IA, Dupuis F, Gianola S, Morgan-Daniel J, Roy JS, Pozzi F, "Addressing Shoulder Weakness in Individuals With Rotator Cuff–Related Shoulder Pain: A Systematic Review With Meta-analysis," Journal of Orthopaedic & Sports Physical Therapy, 2026).
The freshest clinical practice guideline on rotator cuff tendinopathy recommends active, progressive rehabilitation exercise as first-line treatment ahead of passive care ("Rotator Cuff Tendinopathy Diagnosis, Nonsurgical Medical Care, and Rehabilitation: A Clinical Practice Guideline," Journal of Orthopaedic & Sports Physical Therapy, 2025), building on the broader 73-recommendation guideline for rotator cuff disorders (Desmeules F et al., Journal of Orthopaedic & Sports Physical Therapy, 2022).
A 2025 cohort of 296 amateur overhead athletes found isometric ER/IR <0.75 the most prevalent strength-related overuse injury risk factor in both sexes (Intelangelo L et al., Sports Health, 2025), but a systematic review of isokinetic studies found conflicting results overall, with prospective cohorts showing a clearer signal than cross-sectional studies and substantial protocol heterogeneity (Bagordo A et al., "Isokinetic Dynamometry as a Tool to Predict Shoulder Injury in an Overhead Athlete Population: A Systematic Review," Sports, 2020).
EMG evidence shows underuse of the serratus anterior and lower/mid trapezius with overuse of the upper trapezius in subacromial pain syndrome, and scapular stabilization exercise improves scapulothoracic movement and reduces pain (systematic review/meta-analysis, ScienceDirect, 2024; systematic review/meta-analysis of RCTs, Frontiers in Neurology, 2024).
Unlike the substantial ACL-based randomized-trial evidence guiding open- versus closed-chain sequencing at the knee, the shoulder equivalent rests mainly on biomechanical rationale rather than head-to-head trials — presented here as a clinically reasoned progression, not settled, trial-backed sequencing.
Watch
Video walkthrough.
A video walkthrough of shoulder strength rehabilitation will be added here.
Related
Next steps.
Understanding, mobility, strength, and return to sport — the complete phased approach to shoulder rehabilitation.
Restoring range of motion — the stage that typically precedes heavier strength work after surgery or frozen shoulder.
Once strength benchmarks are met, the next stage is testing whether the shoulder is ready for sport-specific demand.
Not sure where your strength stands
Ask Leonardo, or book a strength assessment.
Assessment + treatment from session one. $750 MXN. Zona Rio, Tijuana.