Click here for our video on shoulder mobility: https://youtu.be/kES_U75zME4
Part 2 of the shoulder series focuses on shoulder stability, whereas part 1 focused on shoulder mobility. Both components are equally important. Shoulder stability and shoulder mobility go together… well, like peas and carrots. Everything is about balance. If we stretch the already inhibited muscles of the shoulder girdle to achieve greater mobility, in reality we are doing ourselves an injustive, because we are only taking our shoulder joint further out of balance.
As mentioned in the video, most of our shoulder stability comes from intrinsic muscles throughout the shoulder girdle. The rotator cuff muscles, serratus anterior and rhomboids are primary muscles for shoulder stability. The rotator cuff muscles, as shown in the previous entry, surround the glenohumeral joint (the actual shoulder joint) and each have actions that initiate certain movements.
The supraspinatus, which initiates the first 10-15 degrees of shoulder abduction (raising the arm away from the body out to the side), is the most commonly injured rotator cuff muscle. As you can see from the picture, the supraspinatus travels between the AC joint (where the collar bone and shoulder blade meet) and the shoulder joint. If the shoulder blade is not stabilized efficiently, this will cause an impingement of the supraspinatus, causing pain during pressing and overhead movements.
The infraspinatus and teres minor work together to induce external rotation of the shoulder joint. These muscles were discussed in the previous part of the series. More times that not, when there is a shoulder injury, these muscles are inhibited. Often people have pain in this region, thinking that just because the muscle is “tight”, means that it is shortened and overactivated. In reality, the muscle IS tight, but because the shoulder is internally rotated and these muscles are hanging on for dear life to maintain somewhat of a decent posture.
The fourth and final rotator cuff muscle is the subscapularis, which we also talked about in the last segment. This is a triangular muscle that runs from the anterior (front) aspect of the scapula to the the lesser tubercle of the humerus (front side of arm bone) and controls internal rotation of the shoulder. The subscapularis also helps prevent shoulder dislocation, with an anterior-inferior dislocation being the most common.
A major player in the stability of the shoulder is the serratus anterior, aka the boxer’s muscle. The serratus anterior attaches to the front of top 8-9 ribs and wraps around the body to attach to the scapula. This holds the shoulder blade tight against the rib cage. With weakness of this muscle or poor innervation from the long thoracic nerve, which supplies this muscle, the scapula will be to wing. Scapular winging can limit motion of the shoulder (mainly through shoulder flexion) and instability during pressing movements. In the pictures below, you can see the general anatomy of the serratus anterior. On the picture of Manny Pacquiao, the serratus anterior can be prominently seen as the fingerlike projections to the side and a little below the pec muscles. The third picture shows an example of a winged scapula.
Lastly, the rhomboids (major and minor) are the muscles that run between the spine and the scapulas. When contracted, this causes retraction of the shoulder blade (pulling them inward towards the spine) and assists the serratus anterior by keeping the scapula pulled down to the rib cage. This muscle is crucial in maintaining good posture. Many times pain in the mid back is a direct correlation with rhomboid weakness.
I want to thank everyone for reading our blog and I hope that this is all helpful. Stay tuned for further reading on the blog and through Facebook Live. Next week, there will be a shoulder mobility segment coming out on the news. I will follow that up with some assessments and a tutorial over upper cross syndrome via Facebook Live. Please email me at firstname.lastname@example.org with any questions on the topic. I will be happy to answer them. If you are still unsure on execution or volume of the exercises, call the office and let’s get set up for a consultation and an initial exam. To learn more about Bubba Bush and Brazos Valley Mixed Martial Arts & Fitness, go to www.bvfit.com for class schedules and descriptions.