For your case, the imbalancing muscles might not the major contributing factor to your priformis syndrome.
Sacroiliac joint and lumbar spine dysfunctions might be the real culprits. Lumbar spine dysfunctions, like jammed faced joints, hyerextended ligaments, flattened intervertebral discs or spondylolisthesis, are usually caused by tension, trauma, and poor posture. Nerve root impingement is generated by lumbar spine dysfunctions. and when siactic nerve exits the sciatic notch and is again compressed by piriformis because SI joint dysfunction.
If you expect more effective, successful therapeutic outcomes, integrated myoskeletal manual therapy would be the good option.
