 The goal of this study is to identify if there is a significant prevalence of abnormal respiratory patterns in a sample of patients with low back pain LBP, and if the presence of abnormal respiratory patterns are predictive of rehabilitation outcomes in this population. In addition, the investigators will assess the response to inspiratory muscle training IMT for a subgroup of subjects that maintain abnormal breathing patterns after 1 month of physical therapy. Patients seeking physical therapy for LBP within the Uhealth system will be recruited. The first phase of this study will be observational. A comprehensive assessment of their respiratory function will be performed at the beginning of their therapy and after 1 month of therapy. Subjects that demonstrate abnormal respiratory patterns after 1 month of therapy will be offered the opportunity to participate in the second phase of the study in which they will receive 1 month of inspiratory muscle training IMT. The respiratory assessment will then be repeated at the end of the IMT training program. 