A 26-year-old male presents with a history of
gradual onset of low back pain, which is increased at night. He has stiffness
of his spine, which is worse in the morning. The stiffness is relieved by
Magnetic resonance imaging of his spine reveals
irregularities, erosions and sclerosis of his sacroiliac joints.
In this patient which of the following is likely to
be the earliest objective sign of spinal involvement?
a) Loss of
lateral flexion of the lumbar spine
straight leg raising test
femoral stretch test