The phrase "tight piriformis" refers to a condition where the piriformis muscle, located in the buttocks, becomes tense and contracted. This can cause discomfort and pain in the buttocks, lower back, and down the leg. Full definition
The video below also illustrates a simple one - minute daily stretching routine8 that can help reduce sciatic pain stemming from an overly tight piriformis muscle in your buttocks. (healthy-holistic-living.com)
Tight piriformis by itself can cause the pain in the butt, but the situation becomes worse if it presses on the sciatic nerve that passes underneath (and for some people right through) the piriformis muscle. (yogauonline.com)
Weak or tight piriformis muscles can lead to a variety of problems, both in sports and in everyday life. (verywellfit.com)