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