Relationship Between Chiropractic Care and Autonomic Nervous System Regulation
Condition: Chiropractic Maintenance Care and Heart Rate Variability
Study type: Interventional

Summary: 
      The objective for this study is to explore the utility of biometric devices to measure
      changes in heart rate variability (HRV) during chiropractic maintenance care. The study will
      use WHOOP wearable technology to measure HRV. Chiropractic maintenance care refers to regular
      visits to manage recurrent musculoskeletal pain and dysfunction [1]. Beyond managing pain and
      dysfunction, regular chiropractic visits may also promote improvements in homeostatic
      regulation of internal physiological conditions, but the evidence-based is lacking for these
      effects [2]. The hypothesis of this study is that chiropractic maintenance care may lead to
      an increase in HRV as compared to a control group that do not receive chiropractic care.

        1. Eklund A, Jensen I, Lohela-Karlsson M, Hagberg J, Leboeuf-Yde C, Kongsted A, et al. The
           Nordic maintenance care program: Effectiveness of chiropractic maintenance care versus
           symptom-guided treatment for recurrent and persistent low back pain-a pragmatic
           randomized controlled trial. PLoS One. 2018;13:e0203029.

        2. Kovanur Sampath K, Mani R, Cotter JD, Tumilty S. Measureable changes in the
           neuro-endocrinal mechanism following spinal manipulation. Med Hypotheses.
           2015;85:819-24.
    

Detailed description: 
      The study design is a pragmatic feasibility trial comparing the effects of chiropractic
      maintenance care versus a control group, no chiropractic care, on heart rate variability
      (HRV) in healthy male adults. The subjects in both groups will be healthy controls as the
      purpose of the study is to determine beneficial effects, if any, of chiropractic maintenance
      care on physiological function as opposed to pain management. The theoretical framework
      suggests a potential role of chiropractic maintenance care in the prevention of segmental
      dysfunction in the spine and cascading neuro-endocrine responses to biomechanical stress of
      the spinal segments, hypomobility [1, 2].

      Chiropractic maintenance care will be for a duration of 8 weeks with subjects scheduled for
      one visit per week. Control subjects will be asked to refrain from chiropractic care for 8
      weeks. All subjects will be asked to maintain the current status of their lifestyle behaviors
      for the duration of the study period, e.g. do not change diet or exercise training schedules.
      Using the WHOOP wearable technology to record daily HRV, the primary outcome is the weekly
      average of HRV. There will be a baseline week of HRV recordings prior to starting the
      intervention phase of the study. An increase in HRV of at least 6.5% from baseline to 8 weeks
      without a concomitant change in the control group will provide preliminary insights on
      chiropractic maintenance care and regulation of autonomic nervous system functions. As this
      is a feasibility study to explore the utility of biometric devices to measure changes in HRV
      during chiropractic maintenance care, sample size is limited to 20 subjects.

      The 20 subjects will be healthy male adults from 18 to 40 years old. Given the small sample
      size. females are being excluded to avoid any confounding effects of menstrual cycle on the
      measurement of HRV. The summary of the evidence to date indicates medium to large effects in
      fluctuations of HRV across the menstrual cycle [3]. The study design will include simple
      randomization of subjects into chiropractic maintenance care or control group. The
      intervention group will receive weekly chiropractic care, in the form of high velocity, low
      amplitude (HVLA) chiropractic adjustments delivered to restricted vertebrae of the cervical,
      thoracic and lumbar spinal segments. Motion palpation of the spine will be used to identify
      restricted vertebrae of the cervical, thoracic and lumbar spinal segments. Subjects in the
      intervention group who do not attend at least four (4) scheduled chiropractic visits will be
      withdrawn from the study. Subjects in the control group who receive more than two (2)
      chiropractic treatments (visits) will be withdrawn from the study. Subjects in either group
      who receive more than two (2) other complementary and alternative (CAM) therapies (visits)
      will be withdrawn from the study.

        1. Kovanur Sampath K, Mani R, Cotter JD, Tumilty S. Measureable changes in the
           neuro-endocrinal mechanism following spinal manipulation. Med Hypotheses.
           2015;85:819-24.

        2. Sampath KK, Botnmark E, Mani R, Cotter JD, Katare R, Munasinghe PE, et al.
           Neuroendocrine response following a thoracic spinal manipulation in healthy men. J
           Orthop Sports Phys Ther. 2017;47:617-27.

        3. Schmalenberger KM, Eisenlohr-Moul TA, Würth L, Schneider E, Thayer JF, Ditzen B, et al.
           A systematic review and meta-analysis of within-person changes in cardiac vagal activity
           across the menstrual cycle: Implications for female health and future studies. J Clin
           Med. 2019;8.
    

Intervention name(s): Chiropractic Maintenance Care
Intervention type(s): Other
Intervention description(s): Subjects will receive high-velocity, low amplitude (HVLA) chiropractic manipulations to areas of defined restriction in the upper cervical spine, thoracic spine, lumbar spine, and pelvis. The clinician will use motion palpation to determine spinal segments with joint restrictions. Subjects will schedule weekly chiropractic visits.
The clinician will not use passive care modalities. The exclusions of passive modalities include heat and cold therapies, electric stimulation, massage, acupuncture, and cupping therapies. Subjects will be encouraged to maintain normal exercise activity levels throughout the study. The clinician will provide instructions on homecare exercises as needed to promote range of motion of spinal segments between chiropractic visits. A single clinician will deliver the HVLA chiropractic manipulations to ensure consistency of chiropractic care throughout the study.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Pragmatic feasibility trial comparing the effects of chiropractic maintenance care versus a control group, no chiropractic care, on heart rate variability in healthy male adults.
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: chiropractic; autonomic nervous system; healthy subjects