Physical Activity on Neurophysiologic Gene Expression Profiles of Chronic Low Back Pain

The Impact of Physical Activity on the Neurophysiologic and Gene Expression Profiles of Chronic Low Back Pain: A Longitudinal Study Protocol

This pilot project will provide an understanding of the contextual variables responsible for chronic low back pain. These variables include, genetic variation, pain sensitivity, reactivity, pain catastrophizing, perceived stress and kinesiphobia. The purpose is to understand the initial efficacy of self-management (SM) strategies on each of these contextual variables, in an effort to inform a personalized approach to managing chronic low back pain and its effect on improved health outcomes.

Chronic low back pain (cLBP) is the second most frequent chronic pain condition in the United States and results in billions of dollars each year in health care expenses, disability and lost productivity. A major factor that contributes to the refractory nature of cLBP is enhanced pain sensitivity, which is an altered state of pain processing that amplifies pain sensation and impairs descending pain inhibition. Enhanced pain sensitivity in patients who develop cLBP is associated with altered expression of pro-nociceptive and inflammatory genes. On the other hand, regular physical activity of at least moderate intensity for 150 or more minutes per week is recommended to reduce pain severity and improve function in individuals with cLBP. Therefore, a deeper mechanistic understanding of the effect of physical activity on the neurophysiologic and gene transcription alterations that characterize cLBP may inform more specific treatment options to optimize pain reduction and reduce the risk of pain chronicity.

The purpose of this longitudinal cohort pilot study is to examine the feasibility, acceptability, and preliminary efficacy of the Problem-solving Pain to Enhance Living Well (PROPEL) self-management (SM) intervention on cLBP. This pre-post intervention study will recruit 40 community dwelling adults (age 18 - 60 years old) with cLBP. They will receive electronic video modules focused on cLBP SM knowledge and weekly phone consultations to facilitate monitoring and problem-solving. All participants will be assessed for primary outcomes including cLBP SM behaviors, physical activity, pain severity and interferance, and pain sensitivity at baseline and every 2 weeks for 12 weeks. The study will examine differential neurophysiologic and gene expression profiles between participants with cLBP at 12-weeks post-intervention and correlate these outcome measures to total duration of physical activity.

Inclusion Criteria:

• be 18-60 years of age;
• have nonspecific cLBP (≥4 on the numeric rating scale; NRS) present for at least 3 out of the last 6 months and ≥ half the days in the past 6 months;
• comprehend English (due to lack of reliability and validity of study instruments and the intervention in non-English populations).
• Have daily access to a computer, tablet or smartphone with access to internet
• Have less than 150 minutes of moderate physical activity a week
• Be willing to wear activity tracker for 12 weeks

Exclusion Criteria:

• Chronic pain at another site or associated with a painful condition (eg., fibromyalgia, neuropathy, rheumatoid arthritis)
• history of comorbidities that affect sensorimotor function (eg., multiple sclerosis, cancer, spinal cord injury, diabetes)
• previous spinal surgery within last 1 year
• presence of neurological deficits such as weakness in the lower extremities (motor strength 4/5 of quads, glutes, hamstrings, EHL)
• bowel or bladder dysfunction such as difficulty voiding or incontinence
• sciatica or (+) leg raise
• positive Romberg test
• being pregnant or within 3 months postpartum
• history of psychological disorders (major depression, bipolar disorder, schizophrenia)
• identification of any "red flag" condition in the volunteer's past medical history that suggests specific LBP as determined by Dr. Kim such as conditions or medications that can affect pain sensitivity
• injury to non-dominant hand or presence of open skin lesions, disturbed sensation, carpal tunnel or rash