Shoulder health can mean different things for different people. For a professional baseball pitcher it may mean being able to throw 50 pitches greater than 90mph without pain, for a swimmer it may mean full pain free range of motion to complete a specific swimming stroke, and for a body builder it may mean being able to shoulder press 150 lbs. In general, we can say that shoulder health is whether or not you can comfortably and effectively perform your activity without pain or limitations in your shoulder.
So what does shoulder health mean to you? And how do you obtain shoulder health for your desired needs?
Boney Anatomy
When discussing shoulder health it is important to understand shoulder anatomy. The shoulder is a very complex joint, and it's important to reference all joints that make up the "shoulder joint." To start, the glenohumeral joint is the primary shoulder joint that people think of. This is a ball and socket joint that is actually described more like a golf ball on a tee. A very shallow socket makes it inherently unstable, which allows for a lot of range of motion - the most of any joint in the body. Next is the acromioclavicular joint (AC joint) and sternoclavicular joint (SC joint) which connect the shoulder to the torso of the body via the clavicle (collar bone). This is the only bony connection the shoulder has to the body! Lastly, a pseudo joint that is important to reference is the scapulothoracic joint. This joint is where the scapula articulates with the rib cage and allows for scapular motion during shoulder movements. We reference it as a pseudo joint because it is not like other joints in the body with articular cartilage and a joint capsule. As you can see, the minimal bone and joint stability requires a huge amount of muscular strength and control in order for this body region to function optimally.
Muscular Anatomy
There are tons of muscles that cross over and control each joint, and we won't go into all the details here. In general this is a good list:
- The rotator cuff stabilizes the GHJ
- The pecs, lats, and delts move the GHJ
- The upper traps and anterior delt help to stabilize the ACJ
- Upper, mid, and lower traps, along with the serratus anterior stabilize and control scapulothoracic movement
Now that we understand the joints that make up the shoulder, and the muscles that control those joints, let's discuss how the shoulder joint moves (movement mechanics). The term that is used to describe the timing and ratio of shoulder motion is scapulohumeral rhythm. It is typically described as a 2:1 ratio, although this is not a universally agreed upon ratio. That being said, if a shoulder has a full 180 degrees of motion (arm straight overhead), 120 degrees should come from the glenohumeral joint and 60 from the scapula. If this normal rhythm is altered, the aforementioned joints, ligaments, muscles, and tendons can take on unwanted and excessive strain, eventually leading to pain and injury. So what causes poor movement mechanics in the shoulder? What happens when anatomy or movement mechanics become altered?
We usually see a problem with either mobility, stability, or motor control of the shoulder. We'll give you two recommendations here to begin developing optimal mechanics.
Proper loading parameters
Specific exercises to ensure each muscle group is adequately trained.
1. Proper Loading Parameters
Ensuring we load tissue progressively and give adequate time to heal and recover after imposing said load on the tissue is crucial for tissue health.
It is also important that we are systematic in the way we approach application of loads to the shoulder joint. In the above shoulder press example, the average person wouldn't walk right into a gym and try to shoulder press 150 lbs. Why? Because the tissue takes time to adapt to the loads applied to it. It takes 6-8 weeks to show muscle hypertrophy gains in the muscle. This means that there is a physical change in the size of the muscle that takes place at the cellular level with an increase in the contractile units of the muscle cell called the myofibrils. It also takes time for the tendons and connective tissue to adapt as well. Tendons adapt by increasing collagen content and cross sectional area, making them more robust to withstand increasing loads over time. So if we apply loads to our body too quickly, our tissue doesn't have time to adapted properly, which can lead to injuries, poor mechanics, and "poor shoulder health".
We can apply this to any type of training or sport that applies to you. Focus on a systematic approach to gradually increase training load so the tissue has time to adapt to ensure healthy functioning shoulders.
2. Specific exercises
It is important to train the shoulder musculature in both isolated movements and global/functional movement patterns. Doing too much of either can lead to improper development and suboptimal performance.
If you have an underlying rotator cuff weakness and you only train large movements like overhead press, bench, push-ups, pull-ups, and burpees, your body will rely on the stronger tissue and bypass the weaker cuff, leading to instability of the GHJ and further stress and strain on the joint. On the other hand, if you only do little isolated band exercises for your cuff and don't adequately overload the entire shoulder with heavier lifts, your tissues won't develop optimally.
Below is a list of a few useful training drills to build healthy shoulder tissue and movement mechanics. We recommend beginning isolated accessory exercises at 3 sets of 15 reps to ensure good blood flow to your tissues. The big global lifts can be done at lower reps ranges of 10-12. Make sure that you choose a resistance level that fatigues you by the end of each set. This ensures adequate overload that will stimulate tissue adaptations.
We hope you enjoyed this article. If you are dealing with shoulder pain and would like expert physical therapy in Eagle Idaho, and the surrounding areas, we would love to help you out.
Written by Dr. Luke Phillips, PT, DPT, OCS