The joints at each end of the collar bone
The AC and the SC joints help roll and spin to allow the arm to reach in all directions
The acromioclavicular joint and the sternoclavicular joint are at each end of the collar bone. The AC joint connects the shoulder blade to the collar bone. The SC joint connects the collar bone to the sternum, or chest bone. The SC joint is the only bony connection the arm has to the axial skeleton. The first rib and the subclavius muscle helps provide stability to the joint.
Together, these joints help roll and spin as the arm reaches in all directions. The clavicle rolls posteriorly as the scapula elevates. As the arm raises, the shoulder blade rotates upward and the collar bone elevates. The collar bone retracts and protracts as the arm reaches across the body and out to the side. It also assists with rotation of the shoulder as well.
If there is stiffness in the SC joint, it can contribute to shoulder impingement because the shoulder blade will be limited as the arm moves. The AC joint is prone to degenerative changes and can get stiff as well. If you have a hard time reaching over 115 degrees into flexion, it is likely that the AC joint is not moving well. These joints can be mobilized by a physical therapist to help you gain more overhead reach if it is determined that they are stiff.
When you are in front of a mirror, notice how your collar bones are resting. They are typically parallel with the ground when looking at them from the front. From the side, you may notice that the SC joint is in front of the AC joint as the natural resting position of the collar bone is in slight retraction. If you notice that yours rest differently, if there is no pain or restricted movement, I would not change a thing! If, however, you notice pain or restricted movement, then addressing this area may be helpful.
If you have some limited movement or pain, here are some tips to try, but be mindful that this is not a comprehensive list and is not meant to be a replacement for medical advice.
Massage your subclavius muscle. Place your fingers along the bottom edge of the collar bone and massage from one end of the collar bone to the other.
Roll a towel and place it along your spine. Lay back and let the shoulders drop down to the floor and turn the palms up. Rest for 5 min taking deep breaths intermittently throughout the 5 min rest.
Lay on your back on a firm surface. Notice your comfort or discomfort here. Does your head easily touch the surface? Do your shoulders? How do your shoulder blades feel? Does your back arch off the surface? Is there pain? Where and how do your hands naturally rest? Can you breathe easily? Give yourself support where you need it and how you need it and slowly, over time, I invite you to try and decrease the support until you can tolerate laying flat on a firm surface without struggle or pain.
Try shoulder rolls by shrugging the shoulders up, back, down, and forward and notice how the shoulder blade moves on the rib cage and notice how the collar bones move. Notice if there is a difference between one side and the other. Visualize the shoulder as if it were moving around the face of a clock and move the shoulder in clockwise and counter-clockwise motions and keep the arms by your sides as you are able.
Practice raising your arm overhead and notice how your arms move. Is there stiffness or pain? Do your ribs flare out to help your range of motion? Does your back arch as you lift the arm? Does one move more easily than the other? Observe the motion and also practice without observation so that you can tune in to your body’s signals about where your pain or stiffness may be originating.
I hope you find this helpful, and as always, I’d love to know if you try any of these suggestions. If so, what do you notice?
Take good care,
Sharon