Low Back Pain and Breathing Pattern Dysfunction
Condition: Low Back Pain
MeSH terms: Back Pain; Low Back Pain
Study type: Interventional

Summary: 
      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.
    

Detailed description: 
      The purpose of the first stage of this study is to assess the association and prognostic
      value of respiratory variables to low back pain presentation and outcomes with standard
      physical therapy care. Thus, a prospective longitudinal cohort, observational repeated
      measures (pre and post testing), design will be used for this portion of the study. Both the
      treating physical therapist and the patient will be blinded to the findings of the
      respiratory assessment in order to minimize the risk of treatment bias. Further, the physical
      therapy plan of care and the interventions administered will be at the therapists' discretion
      and will not be standardized. Typically a multimodal treatment approach is used for LBP,
      which includes: patient education, therapeutic exercises to improve strength, flexibility,
      and motor control deficits, manual therapy to decrease pain and improve joint and soft tissue
      mobility, and physical agents for pain management. By allowing therapists to use their
      clinical judgment, we are maintaining a real world environment which improves
      generalizability of the results. Although this will introduce variability that may confound
      results, there is no evidence that any single treatment approach is superior for addressing
      all LBP patients. Thus, allowing therapists to use their clinical reasoning to subgroup and
      treat accordingly maintains the standard of practice for all patient care.

      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 BPD's 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

      recruitment and data collection will occur through UM facilities, but faculty at Nova
      Southeastern University will be involved with data analysis. Thus, IRB approval will be
      obtained from the University of Miami with a reliance agreement with Nova Southeastern
      University. It is anticipated that data collection will last from 6/2015-6/2016.

      RESEARCH DESIGN AND METHODS

      Subject recruitment

      Patients seeking physical therapy for LBP at the University of Miami will be contacted by
      phone within 1 week of their initial examination. They will then be informed of the purpose
      of the study and the study protocol. If they express interest in participating, they will
      then be scheduled for a separate 90 minute session at the Kendall clinic during which all
      initial data will be collected. In addition, posters (see appendix 6) will be placed in the
      waiting room of 5 of the outpatient physical therapy clinics (Kendall, University of Miami
      Hospital, Bascom Palmer, Pain Center in CRB, and Plantation), all owned and operated by the
      University of Miami, as a recruitment tool as well. Qualifying patients from any of these
      facilities may call for additional information and to request inclusion in the study as well.

      Measurement protocol

      Resting Baseline Data

      First subjects will be interviewed to collect data on their condition and status, as well as
      to screen for inclusion/exclusion criteria. (see Appendix 1 for data collection sheet). The
      subjects will then be asked to complete 3 questionnaires: the Pain Catastrophizing Scale, the
      Modified Oswestry Disability Index, and the Nijmegen Questionnaire (Appendix 2, 3, and 4
      respectively). These questionnaires should take less than 5 minutes each to complete. Prior
      to beginning physical data collection, subjects will be informed to immediately stop any
      activity that causes significant discomfort or increased symptoms during the testing session.
      Then, subjects will be asked to breath forcefully into the Micro MPM (Micro Medical Ltd,
      Chatham, UK) device in order to collect MEP. This will be repeated 3-5 times with a 1 minute
      rest in between each trial. They will then be asked to place the TIRE device in their mouth
      and breathe in forcefully and sustain the breath for as long as possible in order to collect
      MIP and SMIP data. This process will also be repeated 3-5 times. Finally, the subjects will
      be fitted with the Cosmed K4b2 and Respitrace systems; these devices will be described in
      detail later. The k4b2 consists of a rubber mask with a light nylon vest to measure breath by
      breath gas analysis, and the Respitrace consists of merely 2 soft chest straps to measure
      heart rate variability and chest excursion with breathing. The subjects will then lie in the
      supine position for 5 minutes, sit quietly for 5 minutes, and stand quietly for 5 minutes in
      order to gather baseline data in each of these positions. The first 2 minutes in each
      position will be used as an accommodation period and data will not be recorded. Thus data
      analysis will only consist of the data from the final 3 minutes in each of these positions.

      Postural Challenge baseline data

      Subjects will be seated in a stable chair, with the feet on the ground and without back
      support, and asked to perform 3 rounds of resisted shoulder flexion and resisted hip flexion
      on each extremity. A submaximal resistance will be applied manually by the investigator and
      held for 30 seconds followed by 30 seconds of rest. After, they will be asked to lift and
      hold a 25 lb weight for 30 seconds 3 times, followed by 30 seconds of rest between each
      trial. Then they will lift the weight 10 times repetitively in a faster paced rhythmic
      fashion set by a metronome. They will then rest in the seated position for 5 minutes to
      measure recovery heart rate and respiration.

      Inspiratory Muscle Training (IMT)

      Subjects that demonstrate unresolved BPD's upon reassessment after PT treatment, will have
      the option to participate in the second phase of the study. These subjects will be scheduled
      twice a week to receive IMT using the RT2 device and software program (described in detail
      later). The IMT protocol uses biofeedback to train at a specific percentage of MIP and SMIP
      for each inspiratory effort. The program consists of 6 breaths per level, with 6 levels, and
      the ability to alter the rest time between breaths as the subject advances through each of
      the levels. The training session is completed when the subject fails to achieve the selected
      percentage of SMIP twice consecutively, or if they complete all 6 levels for a maximum of 36
      breaths. The IMT program will be set at 60% of each subjects MIP/SMIP and breathing at this
      workload will focus on full deep inhalations using diaphragmatic breathing followed by slow
      prolonged exhalations with each subsequent inhalation being signaled by the RT2 software
      prompt (via visual display on the computer screen) to "Please Inhale". The first level of IMT
      will consist of a 40 second rest period between breaths followed by a 30 and 20 second rest
      period during IMT at levels 2 and 3, respectively. The rest period during IMT at the
      remaining three levels will remain at 20 seconds during which subjects will be prompted to
      prolonged exhalation throughout as much of the 20 second rest period as possible. The
      training session will also be stopped if the subject complains of increased back pain and if
      dizziness, fatigue, or if any other adverse response is noted.

      Post IMT Data Collection

      After 4 weeks, or 8 sessions of IMT, the same data collection protocol will be repeated.
    

Intervention name(s): Inspiratory muscle training
Intervention type(s): Other
Intervention description(s): Subjects that demonstrate unresolved BPD's upon reassessment after PT treatment, will have the option to participate in the second phase of the study. These subjects will be scheduled twice a week to receive IMT using the RT2 device and software program. The IMT protocol uses biofeedback to train at a specific percentage of MIP and SMIP for each inspiratory effort.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: inspiratory muscle training; low back pain; respiration; breathing