This is a common problem particularly in younger patients and we have had a number come into the Sports Clinic with these symptoms. Often it is not due to a tendon or muscle issue but comes from a scapulo-thoracic bursa. This is a potential space that sits between your shoulder blade and chest wall that allows your shoulderblad to move freely. Sometimes when inflamed, it causes cracking and pain.
The first thing to do is to make sure that this is indeed th cause with a clinical assessment and maybe an ultrasound examination of the shoulder.
When we are happy with the provisional diagnosis, I often use a mixture of rehab and acupuncture for symptom management and to improve the condition. Sometimes if this does not work, we have done ultrasound guided cortisone injections for symptoms. Rarely does this require surgical intervention, but if it does, this can also be arranged.
Hope this helps with your question and do let us know if you have any further queries.
Bw
Dr Dinesh