• Definition: trauma or strain of the piriformis muscle that manifests with buttock pain and paresthesia in the distribution of the sciatic nerve
• Pathophysiology: precipitating cause → hypertonicity or spasm of the piriformis muscle → shortening of the muscle → sciatic nerve impingement
• Clinical features
  • Pain in the deep gluteal region, exacerbated by sitting for prolonged periods
  • Pain and paresthesia in the distribution of the sciatic nerve (i.e., buttock pain that radiates down the leg)
  • Externally rotated lower extremity (restricted internal rotation)