The pectoralis minor muscle
The pectoralis minor muscle is the little brother, if you will, of the larger more popular pectoralis major muscle. One of the most important things to remember about this muscle is that it lies over the top of the brachial plexus and can cause trouble down the arm.
What does pectoralis minor mean?
The name of the pectoralis minor muscle describes the general location of this muscle.
Pectoralis comes from the Latin word “pectus” meaning breast. Minor comes from Greek and means “the lesser”. This is the smaller of the two pectoralis muscles.
Where does the pectoralis minor attach?
It originates on the third, fourth, and fifth rib.
It inserts on the coracoid process of the scapula.
What actions does the pectoralis minor do?
- Downward rotation
What are the most common injuries to this muscle?
The pectoralis minor muscle doesn’t necessarily get injured. However, it is important to note that the nerves, as well as the arteries and veins that feed the arm, all run beneath this muscle. If the muscle is strained or gets too tight it can compress these structures, causing problems all the way down the arm. At this point it usually fits in under a condition known as thoracic outlet syndrome.
Postures where this muscle contracts
As we push into the floor and lift our body, our scapulae depress, which is an action of this muscle.
Postures where this muscle lengthens
In dhanurasana the scapulae are retracted, stretching this muscle.