Infraspinatus

The infraspinatus muscle is one of the four muscles that make up the rotator cuff, located on the posterior side of the shoulder blade (scapula).

It plays a crucial role in the stability and mobility of the shoulder joint by enabling external rotation of the arm and assisting in shoulder stabilization during dynamic movements.

For athletes, the infraspinatus is vital as it helps maintain shoulder strength and flexibility, which are essential for activities like throwing, swimming, weightlifting, and any sport that requires overhead or repetitive arm motions.

Proper conditioning and care of the infraspinatus can enhance performance, reduce injury risk, and improve overall shoulder function, making it a cornerstone for athletes across various disciplines.

Baseball Pitcher 2
Infraspinatus

Infraspinatus

Anatomy

[Origin]

  • Infraspinous fossa of scapula

[Insertion]

  • Middle facet of greater tubercle of humerus

[Action]

  • Laterally rotates arm; and acts with rotator cuff muscles

Clinical Relevance

The infraspinatus muscle is clinically significant in overhead athletes due to its role in shoulder stability and external rotation. Repetitive overhead motions, such as those in sports like baseball, tennis, swimming, and volleyball, place high stress on the rotator cuff, including the infraspinatus. This can lead to overuse injuries, tendinopathy, or even tears, which are common issues in this population.

Weakness or dysfunction in the infraspinatus can result in compromised shoulder mechanics, reduced throwing velocity, or pain during overhead activities. Additionally, it is often involved in conditions like rotator cuff impingement or posterior shoulder tightness.

Assessing infraspinatus strength and function is critical in the prevention and rehabilitation of shoulder injuries in overhead athletes, ensuring they maintain optimal performance and avoid long-term damage.

~ Evidence-Based Exercises ~

According to an EMG study, the exercises that demonstrated significant muscle contractions of Infraspinatus are;

  • Standing YTWL Tube Exercises

  • Standing Shoulder External Rotation

  • Prone Shoulder External Rotation

Prone Shoulder ER

Prone Shoulder External Rotation

Standing Shoulder ER

Standing Shoulder External Rotation

Standing YTWL Tube Exercises

Standing Tube Shoulder Exercises

< Reference >

  • Keith L. Moore, Anne M. R. AgurArthur F. Dalley. Moore Clinically Oriented Anatomy 7th Edition, Lippincott Williams & Wilkins, 2013
  • Ellenbecker TS, Dines DM, Renstrom PA, Windler GS. Visual Observation of Apparent Infraspinatus Muscle Atrophy in Male Professional Tennis Players. Orthopaedic Journal of Sports Medicine. 2020;8(10):2325967120958834. doi:1177/2325967120958834
  • Kim TG, Ma R, Yu IY. A study of effective exercise methods and resistance intensity for selective strengthening of the infraspinatus muscle. Journal of Back and Musculoskeletal Rehabilitation. Published online January 9, 2025:10538127241298546. doi:1177/10538127241298546
  • Reinold MM, Wilk KE, Fleisig GS, et al. Electromyographic Analysis of the Rotator Cuff and Deltoid Musculature During Common Shoulder External Rotation Exercises. J Orthop Sports Phys Ther. 2004;34(7):385-394. doi:2519/jospt.2004.34.7.385