The pectoralis minor (L. pectus, chest ; minor, smaller.) is the smaller and lesser-known of the two chest muscles.
It helps stabilize the scapula and is the prime mover in scapular downward rotation. It’s involved in other scapular movements, which I’ll cover later.
It is technically classified as part of the anterior axioappendicular muscle group.
It’s a common misconception that the pectoralis minor is the “upper chest.” However, the upper chest is actually the clavicular head of the pectoralis major.
The pectoralis minor is not even a visible part of the physique. It lies deep to the pec major and upper fibers of the serratus anterior.
From this broad origin on ribs 3, 4 and 5, its parallel-oriented fibers extend superolaterally and converge as they insert on the upper outer shoulder blade. This can be described as a fan-shaped or radiate fiber orientation.
- Pec minor
Origin, Insertion, Action & Nerve Supply
|Anterior surface of ribs 3-5, just lateral to the costal cartilages
|Medial border and superior surface of the coracoid process of the scapula
|Medial pectoral nerve (C8-T1)
Note: There is no such thing as a “pectoralis minor exercise” per say – that is, no exercise targets it directly. However, the pectoralis minor is trained indirectly in different exercises, namely:
- All latissimus dorsi exercises.
- Some pec major exercises, specifically those involving scapular protraction and/or scapular downward rotation (i.e. different variations of the dip, chest fly)
- Some serratus anterior exercises, specifically those that don’t involve an incline or overhead arm position (e.g. flat bench shoulder raise or scap push up).
Stretches & Myofascial Release Techniques:
Self Myofascial Release Techniques
When using these techniques, give special attention to the trigger point shown in the image below.
- Overactive/Short Pectoralis Minor: The pectoralis minor is at least somewhat overactive/short in most people due to spending so much time in hunched-over, shoulders-forward positions (e.g. typing on a laptop, texting on phone, playing video games). This is intensified among weight trainees, who typically do much more training with push exercises than pull exercises. And when they do perform pull exercises, they tend to emphasize vertical pulls over horizontal pulls. All of these movements favor the pec minor, causing it to become even more overactive/shorter. Over time, a postural distortion called upper crossed syndrome (UCS) will likely occur. The overactive/short pec minor causes scapular anterior tilt and scapular protraction, which reciprocally inhibits the rhomboids, lower traps and serratus anterior. This muscle imbalance results in poor thoracic extension and limited scapular upward rotation, which reduces overhead range of motion. It also causes poor scapular retraction, which impairs the ability to perform horizontal pull movements correctly. If not corrected, rotator cuff injuries and neck pain are common. Thoracic outlet syndrome may also occur if the pec minor compresses the brachial plexus.
- If you have overactive/short pec minor, do the following:
- Decrease your chest and lat training volume in your routine by cutting out ? to ½ of your sets for each muscle.
- If you lack full overhead range of motion, replace vertical push exercises (e.g. barbell overhead press) with high-incline exercises (e.g. 75° incline barbell press).
- Be mindful of your posture. Minimize the time you spend sitting or standing in a hunched-over position. If you have to be on a computer all day for work and can’t maintain good posture at all times, be sure to get out of that position and briefly stretch your pecs if possible, every 20-30 minutes.
- Release and stretch your pectoralis minor and pectoralis major everyday, and as part of your warm up before any upper body training.
- Increase your training volume on horizontal pull exercises (e.g. seated cable row, bent over shrug) by doubling the number of sets you’re currently performing, per week. Add in a few sets of direct lower trapezius exercises (e.g. prone cobra, Y raise), since the lower traps only get hit indirectly the horizontal pull exercises.
- If you have upper crossed syndrome, the above bullet points will only help so much. See how to fix upper crossed syndrome (article coming soon) for a complete solution.
- There is no need to do try to strengthen or build up the pec minor, except in the rare case that you’re told to do so by a physical therapist as treatment for a specific injury or condition. For everyone else, this would very likely cause or exacerbate the common issues associated with a overactive/short pec minor.