Noninvasive Evaluation of Trunk Muscle Recruitment after Trunk Exercises using Diffusion-weighted MR Imaging

Abstract

Purpose: We evaluated trunk muscle recruitment in abdominal and back exercises with magnetic resonance (MR) diffusion-weighted imaging.Methods: Twelve men performed bent-knee sit-up, crunch, trunk lateral flexion, and trunk extension exercises. We obtained axial diffusion-weighted images of the trunk before and after each exercise using a 1.5-tesla MR system, calculated apparent diffusion coefficient (ADC) values from the right and left rectus abdominis, lateral abdominal, psoas major, quadratus lumborum, and intrinsic back muscles to evaluate the activity of these muscles during each exercise, and compared ADC values before and after exercise using a paired t-test.Results: The ADCs of the rectus abdominis (right, +19.1%; left, +11.7%), lateral abdominal (right, +15.5%; left, +14.1%), and psoas major (right, +14.8%; left, +15.9%) muscles on both sides increased after the bent-knee sit-up (P < 0.01). The ADCs of the rectus abdominis (right, +16.8%; left, +10.2%) and lateral abdominal (right, +8.4%; left, +7.0%) muscles on both sides increased after the crunch exercise (P < 0.01). Trunk lateral flexion resulted in increased ADC on only the right side of all of the muscles (rectus abdominis, +12.3%; lateral abdominal muscles, +20.3%; quadratus lumborum, +17.1%; intrinsic back muscles, +12.0%; psoas major, +15.4%) (P < 0.01). The ADCs of the lateral abdominal (right, +5.2%; left, +5.6%), quadratus lumborum (right, +6.0%; left, +3.0%), and intrinsic back (right, +13.2%; left, +14.6%) muscles on both sides were elevated after trunk extension (right lateral abdominal muscles and left quadratus lumborum, P < 0.05; other muscles, P < 0.01).Conclusion: Diffusion-weighted imaging reveals the recruitment patterns of superficial and deep trunk muscles in abdominal and back exercises through exercise-induced activation in intramuscular water movement.

MR Imaging for Sportology; Non-Invasive Visualization of the Brain and Muscles

“…The bundles of the muscles can be clearly demonstrated using diffusion tensor tractography. Change of apparent diffusion coefficient has been observed even in the Trunk muscles between before and after training 16) . Change of diffusion tensor parameters after long-distance running (marathon) also has been reported 17) .…”

Study of Relationship between Apparent Diffusion Coefficients of the Masticatory Muscles on Magnetic Resonance Imaging and Temporomandibular Joint Disc Displacement

“…There were no significant age-related differences. osmotic pressure due to metabolite accumulation in the extravascular space, or a combination of these factors, which can increase extravascular water within an exercised muscle (9). In a previous study, Katzberg et al (10) reported that the severity of disc displacement without reduction was greater than that of disc displacement with reduction.…”

Evaluation of masticatory muscles in temporomandibular joint disorder patients using quantitative MRI fat fraction analysis—Could it be a biomarker?

“…In a previous study, the apparent diffusion coefficient (ADC) values on MRI of the masticatory muscles on the painful and non-painful sides were compared in 106 TMD patients with unilateral pain, and the mean ADC values of the muscles on the painful side were significantly greater than those on the non-painful sides (p < 0.01) [31]. Yanagisawa et al [32] reported that an increase in ADC value on the painful side was indicative of edematous changes and indicated an increase in intramuscular water transport, including water diffusion in the extravascular space and microcirculation in the capillary network. In our study, it is thought that the lower FF value on the disc displacement side reflects a relative decrease in fat content due to increased water content resulting from edematous changes caused by pain.…”