 A sample of convenience, consisting of 75 consecutive subjects seeking physical therapy for low back pain, will be selected. These subjects will be measured at the initiation of their physical therapy program and then retested 1 month later, using the procedures described below. Subjects with unresolved BPDs at the time of reassessment will be offered the opportunity to receive 1 month of inspiratory muscle training IMT, which will be the second phase of this study. Subjects that complete the IMT will be retested following the same protocol at the end of the IMT program. All subject 