The goal of this clinical trial is to learn whether platelet-rich plasma (PRP) injection, made from a participant's own blood, can help heal the tendon and improve shoulder symptoms in people with partial tears of the supraspinatus tendon.
The main questions it aims to answer are:
* Does PRP help the tendon heal?
* Does PRP improve pain, shoulder movement, daily function, and shoulder magnetic resonance imaging (MRI) findings?
Researchers will compare PRP plus standard of care (physical therapy) to standard of care alone to see if PRP leads to better healing and better clinical results. Researchers will also study if differences in specific biomolecules in PRP are associated with differences in treatment response.
Participants will:
* receive standard of care treatment, with or without PRP injection depending on the study group
* have blood collected for PRP preparation
* have their pain, shoulder movement, and shoulder function assessed
* undergo shoulder MRI scans
* be followed over time to measure healing and symptom improvement