Why some shoulder injections fail: Brain's pain system may be the culprit

This study aimed to understand why steroid injections for shoulder pain sometimes don't work well. Researchers tested 44 patients with rotator cuff injuries to see if a condition called 'central sensitization'—where the nervous system becomes overly sensitive to pain—affects treatment results. They gave all participants a shoulder injection and then tracked their pain levels, shoulder movement, and quality of life to see if those with nerve sensitivity had worse outcomes.