The numeric pain rating scale (NPRS) was used to capture the patient's level of pain. Patients were asked to indicate the intensity of current, best, and worst levels of pain over the past 24 hours using an 11-point scale ranging from 0 ("no pain") to 10 ("worst pain imaginable"). The average of the three ratings was used to represent the patient's level of pain over the previous 24 hours. This procedure has been shown to have adequate reliability, validity, and responsiveness in patients with LBP and has a minimally clinical important difference of 2-point change in patients with mechanical low back pain.