Abstract

Physical activity impacts health and disease in multiple body tissues including the intervertebral discs. Fluid flow within the disc is an indicator of disc health that can be observed using diffusion weighted magnetic resonance imaging. We monitored activity levels of 26 participants, age 35 to 55 yrs, using Actigraph accelerometers for four days to evaluate vigorous-intensity activity, moderate to vigorous-intensity activity, and sedentary time. Participants underwent structural and diffusion weighted magnetic resonance imaging to evaluate intervertebral disc health and fluid flow. They also underwent bone density scans, carotid artery ultrasounds, a treadmill test, and a physical exam for pain, range of motion, and instability. These measures were used to correlate MRI indicators of intervertebral disc health with participant activity. Participants with any vigorous-intensity physical activity compared with no vigorous-intensity activity had significantly greater L5/S1 apparent diffusion coefficient values (p = 0.002), corresponding to higher freedom of diffusive movement for cellular nutrients and metabolic waste. Sagittal T2 values in the L5/S1 were also higher (p = 0.004), corresponding to higher water content in the discs. Higher apparent diffusion coefficients were also found in participants with more than 30 minutes compared with less than 30 minutes of daily moderate to vigorous physical activity (p = 0.03), and in participants with less than 67% awake time as sedentary time compared with more than 67% sedentary time (p = 0.03). Increased dynamic loading through physical activity and decreased static loading from sedentary time benefit intervertebral disc health. Physical activity, particularly vigorous activity, is beneficial in helping maintain intervertebral disc health.

Degree

PhD

College and Department

Life Sciences; Exercise Sciences

Rights

http://lib.byu.edu/about/copyright/

Date Submitted

2017-10-01

Document Type

Dissertation

Handle

http://hdl.lib.byu.edu/1877/etd9542

Keywords

intervertebral disc health, physical activity, sedentary time

Language

english

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