Lameness examination is essential to diagnosing soundness issues.  Because veterinarians cannot ask their patients where it hurts, they are dependent upon visual cues from the horse as it moves.   A lameness evaluation includes a physical exam, palpation of the limbs and joints, evaluating range of motion, watching the horse travel in a straight line and on a lunge line, and response to flexion of the joints.  Further diagnostics include nerve blocks, joint blocks, radiographs, and ultrasound.