The Pectoralis Major is located on the front of the chest and it attaches to the sterum, clavical and humerus. Its main actions are flexion, internal rotation and adduction of the arm at the shoulder joint and because of its attachment to the clavicle, it can also do some protraction of the scapula. When these actions combine, and if your Pectoralis muscles are strong, it means that you can give some great, big bear hugs- which sounds great. Unfortunately, the Pectoralis Major can also lead to a problem I see too often as a body worker: Slumped Shoulders.
Slumped Shoulders can best be described as what cavemen’s upper bodies used to look like. Shoulders hunched forward and arms internally rotated so that their knuckles could drag. The usual causes of rounded shoulders include poor posture, overuse or sedentary lifestyle (not moving the shoulders enough). When poor posture (which causes adaptive shortening) or overuse occurs the Pectoralis Major becomes extremely tight – this will reciprocally inhibit the posterior shoulder muscles.
Reciprocal inhibition happens because our bodies are built to adapt, so rather than fighting the Pectoralis Major and risking injury, the body overstretches its antagonist muscles. By being in this contracted state the first problem is adhesions or scar tissue will form on the Pectoralis Major, making it more difficult to lengthen without discomfort or injury. It can also cause trigger points to form. Trigger points are areas of hypersensitivity along a muscle fiber which can refer pain. Specifically, trigger points in the Pectoralis Major can refer pain throughout the muscle (chest), into the shoulder and down into the arm, depending on where the trigger point is. The tight Pectoralis muscle can also become so tight that it impinges on the nerves and blood vessels that supply it and the arms. That can lead to decrease of function, loss of sensation or pain radiation down the nerve pathway and loss of nutrient rich blood that feeds the muscles leading to fatigue and pain. On the other side, those posterior shoulder muscles, i.e. rhomboids & mid-trapezius, get fatigued from constantly being overstretched that they cause pain which can feel very similar to what is felt in the Pectoralis Major.
Who is at risk, you may ask? That’s anyone who works with their hands out in front of them for hours a day- so 90% of the population. A shining example for me, living in Fairfield County, CT, would be the commuters. The Wall Street Warriors or Corporate America Captains who spend hours in traffic commuting to NYC – to sit in front of their computers all day – to commute back home again. Most barely take a bathroom break, let alone a break to stretch. This can be cumbersome to their daily lives, dealing with the pain, but it can also greatly affect one’s yoga practice.
As previously discussed, a tight Pectoralis Major can cause rounded shoulders and weakened rhomboids & mid-trapezius. In which poses can these muscles combined cause a snafu in your practice? Inversion poses! Even one as simple as Downward Facing Dog can be affected by misbehaving Pecs and the havoc they wreak. In order to do a strong, well-balanced inversion pose you need a few things: 1- To get your shoulders into the right amount of flexion, 2- To have the ability to retracted and depress the scapulae and to maintain those actions. If a client has tight pecs than both requirements for inversion poses are already compromised. The tight pecs may be limited, as they are always constantly in a contracted state, to get beyond a certain degree of flexion. This has to do with the length-tension relationship of the muscle. The length-tension relationship has to do with the length of the muscle fiber and the force it will produce. Simply stated, if a muscle is too contracted or lengthened, its force will be weaker. In addition, the rhomboids and mid- trapezius would be prime retractors of the scapula but are already weakened. Since the upper body serves as the foundation for inversion poses, if these components are weak than it will lead to diminished poise for the rest of the posture and that could lead to injury.
In order for someone with tight Pectoralis Major muscles to better their yoga practice, as well as normal daily activities, I would recommend the following YTU poses as Pectoralis Major stretches:
Go to wall Squat Arms up with Block – This pose is great practice for correcting your shoulder poise in inversion poses without adding body weight. The chain is still closed at the hands and you have the added bonus of a closed chain at the spine bringing a new proprioceptive awareness to where your scapulae and spine placement are. This can also be used to help strengthen the rhomboids & mid-trapezius muscles.
Epaulet Arm Circles – Helps to bring the shoulders through its full ROM. By having the hands placed on the shoulder joints it really warms up the Pectoralis muscles when bringing the elbows to touch and the rhomboids & mid-trapezius when winging the elbows back in circumduction. This will also bring awareness to the all the muscles of the shoulder girdle complex.
Open Sesame: Uses the floor to pin down & close chain the arm. This allows for the Pectoralis Major to get the deepest stretch possible using body weight & the floor to help horizontally abduct the arm away from the chest.