External rotation is done with the elbow pinned to your side, on a band or a cable, with a load that looks too light to matter. The studies that measured it say the light load is the right setting.
Shoulder external rotation turns the arm outward with the elbow bent at 90°. It trains the infraspinatus and the teres minor, the two rotator cuff muscles that produce that movement. Eight studies show which position works them hardest, which load keeps the deltoid out of it, whether a band matches a cable, and what is known about its link with shoulder pain in people who lift.
Which muscles external rotation works
The rotator cuff is four muscles around the shoulder joint: the supraspinatus, the infraspinatus, the teres minor and the subscapularis. The infraspinatus and the teres minor turn the arm outward. The subscapularis turns it inward, it is the internal rotation muscle.
The posterior deltoid also takes part in external rotation. Bitter et al. (2007) saw it fire together with the infraspinatus, even at low loads. The Overload exercise library does not separate these muscles: it files every shoulder rotation under a single group, Shoulders.
Which position works the infraspinatus hardest
Reinold et al. (2004) placed electrodes inside the muscles of ten healthy subjects and compared seven external rotation exercises. Side-lying with the elbow at the side produced the highest activity of the infraspinatus, 62% of maximal isometric contraction, and of the teres minor, 67%.
The other muscles peaked elsewhere. The supraspinatus (82%), the middle deltoid (87%) and the posterior deltoid (88%) were highest lying prone, arm out at 100° and in full external rotation. That position works the whole back of the shoulder, side-lying targets the two external rotators more.
Out of seven external rotation exercises, the side-lying version with the elbow at the side activated the infraspinatus (62%) and the teres minor (67%) the most. The study has ten subjects and measures activity, not strength gains.
Why a light load is the right setting
Bitter et al. (2007) had 18 subjects hold an isometric external rotation at 10%, 40% and 70% of their maximal strength, with and without squeezing the elbow into the body. The aim was to find the load that gives the infraspinatus the largest share of the work relative to the deltoid.
The answer is a load between 10% and 40% of maximum: that is where the infraspinatus does the largest share of the work with the least deltoid. At low loads, squeezing the elbow into your side also cuts middle deltoid involvement. The posterior deltoid fires in parallel with the infraspinatus from low loads on.
Light load (10 to 40% of max)
Largest share of the work for the infraspinatus, with the middle deltoid held back if the elbow stays squeezed into the body (Bitter et al., 2007).
Heavy load (70% of max)
Outside the range Bitter et al. (2007) settled on: the infraspinatus no longer does the largest share of the work relative to the deltoid.
Band or cable
Andersen et al. (2010) compared dumbbells and elastic tubing in 16 women on three exercises, shoulder external rotation among them. At each woman's maximal load, defined as a 3RM, prime-muscle activity did not differ between dumbbells (59 to 87%) and elastic tubing (64 to 86%). Perceived effort on the Borg CR10 scale tracked measured activity (r = 0.59 to 0.92).
A band has one drawback for tracking progress: its color is not a weight. Uchida et al. (2016) measured the tension of eight Thera-Band colors at ten elongation levels, from 25% to 250%. For five colors, the manufacturer's values overestimated the measured tension. The same color gives a different load depending on how far you stand from the anchor.
A cable gives a readable load: the plate you pick stays the same from one session to the next. The cable training guide covers what the cable changes compared with free weights.
The rotator cuff and shoulder pain in lifters
Kolber et al. (2010) reviewed injuries attributed to resistance training: up to 36% of documented injuries and disorders involve the shoulder. Most studies in the review were retrospective and could not identify what predicts an injury.
Kolber et al. (2014) examined 46 weight-training participants and 31 controls with two clinical tests for subacromial impingement. Signs of impingement were associated with lateral raises and upright rows above 90°, and inversely associated with external rotator strengthening. In 2017 the same group found lower bodyweight-adjusted strength of the external rotators and lower trapezius in 24 lifters with these signs than in 31 lifters without.
Both studies are cross-sectional: they show an association, not that external rotation protects the shoulder. The strongest controlled trial comes from another sport. Andersson et al. (2017) followed 660 elite handball players for a season. The program tested, three times a week as a warm-up, combined external rotator strengthening, shoulder blade muscle strength and mobility. Shoulder problem prevalence was 17% against 23% in controls, a 28% lower risk of shoulder problems (odds ratio 0.72). The effect belongs to the whole program, in throwing athletes.
How to do external rotation
- Stand with the band or cable at elbow height, on the side opposite the working arm. Elbow bent at 90°, pinned against your side, forearm across your stomach.
- Turn the forearm outward without lifting the elbow off your side. The elbow is the pivot, it does not drift back or out.
- Return slowly to the start, without letting the band or cable snap the arm back.
- For the side-lying version, lie on the opposite side, top elbow against your ribs, and raise a light dumbbell with the same rotation.
Set the load by feel rather than by a number. Bitter et al. found the best infraspinatus share between 10% and 40% of maximum, and Andersen et al. showed that perceived effort tracks muscle activity. If the elbow lifts off or the torso turns, the load is too heavy.
Shoulder rotations in the Overload library
The Overload exercise library has 897 movements, 130 of them filed under Shoulders, and 17 primary muscle groups. The rotator cuff is not one of them, so the seven shoulder rotations are classified alongside the lateral raise.
| Variation | Movement | Secondary muscles | Member uses |
|---|---|---|---|
| External Rotation with Band | External rotation, band | None | 0 |
| External Rotation with Cable | External rotation, cable | None | 0 |
| External Rotation | External rotation, free weight | None | 0 |
| Reverse Flyes With External Rotation | Reverse fly with external rotation | None | 0 |
| Cuban Press | External rotation and press | Traps | 0 |
| Internal Rotation with Band | Internal rotation, band | None | 0 |
| Cable Internal Rotation | Internal rotation, cable | None | 0 |
| Face Pull | Pull toward the face | Middle back | 238 |
| Side Lateral Raise | Lateral arm raise | None | 1,194 |
The counter adds up the logged sessions each movement appears in. It counts neither sets nor people, and it does not say how long each movement has been in the library.
Shoulder exercises add up to 6,209 recorded uses. None of them is a rotation, internal or external. The side lateral raise alone has 1,194, and the face pull, filed under Shoulders with the middle back as secondary, has 238.
The library links the three external rotations to each other: each one lists the other two as alternatives, plus the cable internal rotation as the opposite movement. Band, cable and free weight are treated as three versions of the same movement, and Andersen et al. (2010) measured comparable activity between band and dumbbell.
Practical recommendations
- Pick the side-lying version if the infraspinatus is the target. It activated it the most in Reinold et al. (2004).
- Keep the load light enough to control without the elbow lifting off. Between 10% and 40% of maximum, the infraspinatus does the largest share of the work (Bitter et al., 2007).
- Squeeze the elbow into your side for the whole set to hold back the middle deltoid.
- Use whatever equipment you have. At equal maximal effort, band and dumbbell give comparable muscle activity (Andersen et al., 2010).
- With a band, note the color and the distance from the anchor. Real tension does not always match the manufacturer's figure (Uchida et al., 2016).
- If your shoulder sessions revolve around lateral raises and presses, external rotation is a short add-on at the end of the session. The bent-over row guide covers the other big block of work for the back of the shoulder.
One band color, one historyOverload is a structured strength-training app. Each exercise has a Comment button next to adding a set: write down the band color and the distance from the anchor there, so your external rotation sets compare from one week to the next. No free cable station? The exercise picker suggests alternatives with the reason for each. In the Analytics tab, every exercise opens its progression chart and history. Get Overload and add external rotation to your next shoulder session.
Conclusion
External rotation trains the infraspinatus and the teres minor, and works them hardest side-lying, elbow at the side, with a light load. Band and dumbbell give comparable activity, and a cable gives a load that is easier to track. Overload members have logged 6,209 uses of shoulder exercises and not one rotation.
- Reinold MM, Wilk KE, Fleisig GS, et al. (2004) — Electromyographic analysis of the rotator cuff and deltoid musculature during common shoulder external rotation exercises. J Orthop Sports Phys Ther, 34(7), 385-394.
- Bitter NL, Clisby EF, Jones MA, et al. (2007) — Relative contributions of infraspinatus and deltoid during external rotation in healthy shoulders. J Shoulder Elbow Surg, 16(5), 563-568.
- Andersen LL, Andersen CH, Mortensen OS, et al. (2010) — Muscle activation and perceived loading during rehabilitation exercises: comparison of dumbbells and elastic resistance. Phys Ther, 90(4), 538-549.
- Uchida MC, Nishida MM, Sampaio RA, Moritani T, Arai H (2016) — Thera-band elastic band tension: reference values for physical activity. J Phys Ther Sci, 28(4), 1266-1271.
- Kolber MJ, Beekhuizen KS, Cheng MS, Hellman MA (2010) — Shoulder injuries attributed to resistance training: a brief review. J Strength Cond Res, 24(6), 1696-1704.
- Kolber MJ, Cheatham SW, Salamh PA, Hanney WJ (2014) — Characteristics of shoulder impingement in the recreational weight-training population. J Strength Cond Res, 28(4), 1081-1089.
- Kolber MJ, Hanney WJ, Cheatham SW, et al. (2017) — Shoulder Joint and Muscle Characteristics Among Weight-Training Participants With and Without Impingement Syndrome. J Strength Cond Res, 31(4), 1024-1032.
- Andersson SH, Bahr R, Clarsen B, Myklebust G (2017) — Preventing overuse shoulder injuries among throwing athletes: a cluster-randomised controlled trial in 660 elite handball players. Br J Sports Med, 51(14), 1073-1080.
This article presents the current scientific evidence. If your shoulder hurts, or for a personalised program, consult a health professional.