Muscles / Shoulders
Infraspinatus
- Shoulders
- Shoulder & scapula
- Intermediate layer
Anatomy
- Origin
- Infraspinous fossa of the scapula
- Insertion
- Middle facet of the greater tubercle of the humerus
- Nerve
- Suprascapular nerve (C5-C6)
Actions
- Laterally rotates the arm
- Stabilises the humeral head (rotator cuff)
Exercises that train it most
Side-lying external rotation
Standing external rotation with band (0° abduction)
Cross-body stretch
Sleeper stretch
Also trained by
Notes
- Side-lying external rotation produced its highest EMG (62% MVIC) among common ER exercises.
- Isolated infraspinatus atrophy suggests suprascapular nerve entrapment at the spinoglenoid notch.
References (5)
- Reinold MM, Wilk KE, Fleisig GS, et al. J Orthop Sports Phys Ther. 2004;34(7):385-394. Electromyographic analysis of the rotator cuff and deltoid musculature during common shoulder external rotation exercises
- Standring S, ed. Elsevier. Gray's Anatomy: The Anatomical Basis of Clinical Practice. 42nd ed.
- Dalley AF, Agur AMR. Wolters Kluwer. Moore's Clinically Oriented Anatomy. 9th ed.
- Neumann DA. Elsevier. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 3rd ed.
- Betts JG, Young KA, Wise JA, et al. OpenStax (free, openly licensed textbook). Anatomy and Physiology 2e