Authors: Atsushi Imai, PhD
Journal of Orthopaedic & Sports Physical Therapy, 2016 Volume:0 Issue:0 Pages:1–25 DOI: 10.2519/jospt.2017.6730

Study Design
Controlled laboratory study; pre-test post-test.

Background
Diffusion-weighted (DW) imaging is a non-invasive magnetic resonance imaging technique that can be used to assess the recruitment of the psoas major (PM) and quadratus lumborum (QL). The recruitment of these muscles during trunk exercises has not been evaluated.

Objective
To evaluate the diffusion of water movement in several trunk muscles using diffusion-weighted (DW) imaging before and after specific trunk exercises in order to understand the level of recruitment of each muscle during each exercise.

Methods
Nine healthy male participants performed the right side bridge, knee raise, and three front bridges, including the hand-knee, elbow-knee, and elbow-toe. DW imaging was performed before and after each exercise. After scanning, the apparent diffusion coefficient (ADC) map was constructed, and ADC values of the rectus abdominis (RA), lateral abdominal muscles, QL, PM, and back muscles were calculated.

Results
The ADC value of the right PM, after the elbow-toe, demonstrated the largest increase, and was significant greater change than that of the hand-knee (P<.001) and side bridge (P=.002). For the right QL, the ADC change of the side bridge was significantly larger than that of other exercises (P<.008). Conclusion Of the 5 exercises investigated, the elbow-toe and side bridge elicit the greatest recruitment of the PM and QL, respectively. J Orthop Sports Phys Ther, Epub 5 Nov 2016. doi:10.2519/jospt.2017.6730 Journal Abstract