Infraspinatus: Functional Anatomy Guide

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By Alex
Last updated on

The infraspinatus (L. infra, below ; spinus, spine [of scapula]) is a thick rotator cuff muscle covering the majority of the posterior surface of the shoulder blade below the scapular spine.

InfraspinatusIt is a prime mover in shoulder external rotation and plays important roles in shoulder stability. Most notably, it prevents excessive anterior and posterior migration of the humeral head.

The infraspinatus is very similar to the teres minor, in terms of function and location. They can be hard to tell apart due to their proximity and similar fiber direction, and are sometimes actually fused together.

Classified as a scapulohumeral (intrinsic shoulder) muscle, the infraspinatus is situated lateral to the rhomboids, inferior to the supraspinatus and superior to the teres minor.

The medial portion of the muscle is visible from the surface of the physique, while the rest of it lies deep to the posterior deltoid.

The infraspinatus arises from the infraspinous fossa, passes over the humeral head and inserts on the greater tubercle of the humerus.

The fibers run obliquely between multiple tendinous septa, forming a multipennate muscle architecture.

Also Called

  • Rotator cuff
  • External rotator

Origin, Insertion, Action & Nerve Supply

Muscle Infraspinatus
Origin Infraspinous fossa of scapula
Insertion Middle facet of the greater tubercle of the humerus
  • Shoulder external rotation
  • Shoulder horizontal abduction
  • Shoulder extension
  • Anterior shoulder stability
  • Posterior shoulder stability
Nerve Supply Subscapular nerve (C4-C6)


Note #1: The table below only includes exercises that train the infraspinatus directly by focusing on its main action of external rotation. Other exercises that train the infraspinatus indirectly include many posterior deltoid exercises and some Olympic-style lifts (i.e. all clean, snatch and pull variations).

Note #2: The word “upright” in the context of an “upright shoulder external rotation” exercise, refers to the upper arm being abducted to 90° (i.e. arm is up and out to the side, parallel to the floor).

Barbell Exercises:

  • Cuban rotation
  • Cuban press

Dumbbell Exercises:

  • Standing upright shoulder external rotation
  • Seated upright shoulder external rotation
  • Standing upright supported shoulder external rotation
  • Seated knee-supported shoulder external rotation (90° shoulder flexion)
  • Side lying shoulder external rotation
  • Prone shoulder external rotation
  • Incline shoulder external rotation
  • Incline side lying shoulder external rotation
  • Incline row to external rotation
  • Unilateral YTL
  • YTWL

Cable Exercises:

  • Standing shoulder external rotation
  • Seated shoulder external rotation
  • Standing shoulder external rotation
  • Seated shoulder external rotation
  • Face pull with external rotation

Machine Exercises:

  • Shoulder external rotation
  • Upright shoulder external rotation

Bodyweight Exercises:

  • Prone shoulder external rotation
  • Incline shoulder external rotation
  • Incline row to external rotation
  • Unilateral YTL
  • YTWL
  • Scapular wall slide
  • Side lying extension rotation
  • Side lying internal-external rotation
  • Side lying windmill

Stretches & Myofascial Release Techniques:


  • Broomstick infraspinatus stretch
  • Bent over infraspinatus stretch
  • Seated bent over infraspinatus stretch
  • Side lying infraspinatus stretch
  • Side lying teres minor stretch (aka sleeper stretch)

Self Myofascial Release Techniques

When using these techniques, give special attention to the common trigger points shown in the image below.

infraspinatus trigger points


  • Lacrosse ball
  • Backnobber II

Common Issues:

  • Inhibited/Excessively Lengthened Infraspinatus: The infraspinatus tends to become inhibited and excessively lengthened in those with upper crossed syndrome (UCS). The shoulder internal rotation associated with UCS facilitates the internal rotators, which in turn reciprocally inhibit and stretch out the infraspinatus and other external rotators. Often, this chronically internally rotated position is brought on by: overuse of the internal rotators due to poor postural habits (i.e. hunching over, lots of sitting, using on a computer, etc.); a disproportionate focus on push and vertical pull exercises relative to horizontal pull exercises, and exercises involving internal rotation rather than external rotation.
  • Overactive/Short Infraspinatus: An overactive and short infraspinatus is less common a weak and lengthened one. However, overactivity/shortening of the muscle is prevalent among overhead throwing athletes (e.g. pitchers, quarterbacks), who are constantly going into external rotation due to the nature of their sport. This can cause overuse of the infraspinatus, making it and the other external rotators overactive and short. This, in turn, can reciprocally inhibit the subscapularis, leading to poor internal rotator strength and range of motion. Overuse beyond a certain point can lead to injuries, such as a infraspinatus tear.
  • Weakness from Infraspinatus Tear: The infraspinatus is the second most commonly torn rotator cuff muscle (supraspinatus tears are most common). Overuse of the infraspinatus can eventually result in a tear, since the muscle is continually enduring microtrauma. Thus, it’s more likely to tear under intense exertion. However, a tear can also be the result of damage from subacromial impingement. In this case, the supraspinatus tears first since it is first to be impinged. But eventually, the tear can expand to the infraspinatus.

Training Notes:

  • If your infraspinatus is inhibited and excessively lengthened, consider the following:
    • Increase your training volume on infraspinatus exercises.
    • Increase your training volume on rear deltoid exercises. This will strengthen the rear delt, which is an external rotator and likely weak. Plus, these exercises train the infraspinatus indirectly.
    • Release and stretch the internal rotators (subscapularis, pectoralis major, latissimus dorsi, anterior deltoid, teres major) on a daily basis, and especially before infraspinatus or rear delt exercises. This calms down these overactive muscles, allowing you to better activate the external rotators and improve your range of motion during external rotation.
    • As mentioned earlier, this problem may be a symptom of upper crossed syndrome. If this is the case, you need to address that for a complete solution. Read how to fix upper crossed syndrome (article coming soon).
  • If your infraspinatus is overactive and short (especially if you’re an overhead throwing athlete), consider the following:
    • Release and stretch the infraspinatus, teres minor and rear deltoid. Do this on a daily basis, including before exercises involving an internally rotated position (i.e. most upper body exercises; anything from DB internal rotations to bench to rows to pull ups). This will help improve internal rotator muscle activation and range of motion.
    • Increase training volume on the subscapularis exercises. The larger internal rotator muscles – such as the pec major, lats and front delt – may not actually need any additional training (in fact, they may be overactive/short and synergistically inhibiting the subscap).
    • Try to avoid exercises involving extending the arm behind the torso (e.g. dips) and overhead exercises (e.g. overhead press), especially if you are an overhead/throwing athlete. If you refuse to avoid these exercises, at least minimize training volume use low training intensity when doing them.
    • If you have excessive kyphosis, do thoracic mobility exercises to improve thoracic extension and thoracic rotation. This should reduce your kyphotic curvature and allow your scapulae to sit properly against the ribcage. Not only can this increase shoulder external rotation range of motion, but it can also improve increase shoulder internal rotation range of motion, which overhead throwers often lack (see this article).
    • The correct approach for overhead throwing athletes ultimately depends on a number of individual factors. For more detailed information on this, I recommend reading this, this and this to start with.
  • For general infraspinatus training guidelines and exercise technique tips, see below:
    • It’s easy to accidentally train the wrong muscles when doing certain infraspinatus exercises. When starting out, avoid the technically difficult exercises in favor of easier ones:
      • Easier: Any supported upright shoulder external rotation variation (90° abduction) or any dumbbell lying shoulder external rotation variation (0° shoulder abduction). Choose just one or two of these when starting out.
      • Harder: Any non-supported upright shoulder external rotation variation (90° abduction) and any cable shoulder external rotation variation (0° shoulder abduction). Don’t do these until you’ve learned how to activate the infraspinatus properly and have strengthened it noticeably with the easier exercises.
    • Use light weight for medium to high reps (8-15+) on direct infraspinatus exercises. Never go to failure. After all, the infraspinatus is a small muscle, and part of a delicate structure. Using more weight than you can reasonably handle is ineffective at best, and dangerous at worst.
    • Do 2-4 sets of infraspinatus exercises, 1-3 times per week. This does not include any sets you may do to warm up before upper body training workouts (see next bullet point).
    • Do a couple very light sets of any one infraspinatus exercise before workouts involving compound upper body exercises. It’s essential to avoid fatigue on these sets. You should use even lighter weight than on your normal working sets (see previous bullet point).
    • On any dumbbell lying shoulder external rotation variation, place a small rolled-up towel between your elbow and torso. This improves your form by keeping your upper arm in the correct position.
Alex from King of the Gym
Hey! My name is Alex and I'm the founder and author of King of the Gym. I've been lifting weights seriously since 2005 in high school when I started a home gym in my parents' basement. I started writing about fitness in 2009. Then, in 2014, I got into writing home gym equipment reviews and I haven't looked back. My current home gym is in my own house and it's constantly growing and evolving. My goal is to help you build the home gym of your dreams! Read more about me here.

3 thoughts on “Infraspinatus: Functional Anatomy Guide”

  1. Thank you for this excellent website. The information is sooo helpful. The layout and format is superb. It’s got all the information you could possibly need. Am having trouble with my rotator cuff and the anatomy sections on the infraspinatus and anterior delt are just what I needed. THANK YOU.

  2. Hi Alex….
    Thanks for your informative website.
    I’ve got both a supraspinatus & infraspinatus tear & can barely move my arm. Are there any exercises that you’d suggest that I can do, so I hopefully won’t have to have surgery?
    Thanks…. Tandi


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