low back pain with leg pain

hello everyone!
i hope someone can help me out with a patient i am treating at present.patient presented with low back pain on the left side around the psis region and in the buttock going to the lateral side of the leg and upper thigh. all neurodynamic tests were negative.he has had a thr on the other side a year back.the right leg has good muscle strenght and flexibility. the left side had extremely tight hams and piriformis. i started with stretches for the two and some trigger point relesases in the buttock area( he had reffered pain to the back of the leg and calf sometimes when i pressed some points on the buttock). he is felling much better after 3 sessions. pain has reduced markedly. but wen he extends his right leg( unaffected leg)( like we do our quads stretch in standing) he has this dull ache going thru the back of the left leg from the buttock to the calf?? i am not sure wat that is? can someone help me. it takes around 2 minutes for the symptoms to subside.
hope i can help the patient with ur views . thank you.. have a nice day.

Hi there,
Have you assessed the sacroiliac joints? If this person has unilateral glut tightness and very low lower back pain they could be involved. Especially when movements of the opposite side cause aggravation as the joints work in pairs

Need more info. However, the McKenzie Technique (McKenzie, 2003. The lumbar spine mechanical diagnosis & therapy) provides significant assessment and treatment information. Trauma/posture/degeneration? Pt history? Stage of healing? Mechanical (localised pain, intermittent pain, pain aggravated by mechanical factors in a consistent manner, x-rays) or chemical pain (constant pain, night pain, pain unaffected by mechanical loading, blood tests, inflammatory conditions: ank spond/ osteoarthritis/ osteomyelitis/ Reiter's syndrome/ rheumatoid arthritis/ septic arthritis/ tuberculosis)? What is patient's directional preference? Centralisation or peripheralisation with repeated back extension/ flexion/ lateral bending? Painful arc/ obstruction block? PAIVMs? PPIVMs? Prone instability test? Meds? You mentioned: Rt leg extension causes dull ache to buttock/posterior Lt leg/calf is representative of facet joint pain/pathology, possibly due to 'rotated vertebral segment', also aggravated by spondylolysis/ spondylolisthesis? I believe this will cover lumbar spine pathologies, then to progress to sacroiliac joint assessment. I look forward to following up with this case study.
Cheers,
Phil