The musculoskeletal examinations at baseline and follow-ups will be performed by a physiotherapist. It will include examination of the lower back spine, pelvis and assessment of physical functioning. Briefly, the lower back spine will be examined by palpation of ligaments and paravertebral muscles, Kemp's foramina test, Valsalva test, SLR (straight leg raising test) and test of tendon reflexes and sensibility. The pelvis will be examined by the following tests: P4 test, Menell's test, Patrick's faber test, modified Trendelenburg test and the pubic symphysis palpation test.