Deltoid Training Cautions (Subluxation & Rotation)

Safety points for deltoid training:

• Anterior deltoid: positioning the upper arm 45 degrees away from the torso is an important safety factor to prevent subluxation of the shoulder joint. A neutral grip is a more functional movement to train this muscle (it is over-used and primarily involved in pressing).
• Medial deltoid: ROM is 90 degrees (shoulder-joint abduction). Beware of internal and external rotations. Note the greater-tubercle / acromion-process relationship and limitation (impingement — the bones can rub against one another). This position does not allow the use of heavy weights.
• Posterior deltoid: the most under-emphasized of the three heads; movements are rarely done properly. The key is horizontal abduction (extension). The press-behind-neck exercise is not recommended as it involves too much external rotation.

• Hold the upper arm 45° from the torso to prevent shoulder subluxation (anterior deltoid).
• Medial deltoid ROM = 90° abduction; beware internal/external rotation; risk of greater-tubercle/acromion impingement; do not use heavy weights.
• Press-behind-neck not recommended — too much external rotation.

• anterior-deltoid / medial-deltoid / posterior-deltoid — the three deltoid heads.
• rotator-cuff-low-resistance — related shoulder-stabilizer caution.
• behind-neck-press-not-recommended — behind-neck pressing risk.
• internal-rotation / external-rotation — rotations to beware.