Measurement Of Muscle Thickness In The Forearms Of Rock Climbers Using Ultrasound

Abstract

The flexor muscles of the forearm are repeatedly found to be the rate limiting factor in performance for rock climbers. Previous studies have shown that cross sectional area (CSA) measurements via Magnetic Resonance Imaging (MRI) have a strong correlation to ultrasound measured muscle thickness (MT) in the forearm flexors. However, few studies have employed this relatively low-cost alternative to MRI to assessing forearm muscles of rock climbers. PURPOSE: To compare differences in MT of the finger flexors in the forearms of early-stage rock climbers and non-rock climbers using ultrasound. METHODS: The study consisted of 22 climbers (22.23±3.01 year; 68% male) and 11 controls (21.91±1.97; 55% male). Body fat percentage and BMI were measured in all participants. An image of the thickest portion of the forearm, from the ulna and radius to the muscle-skin interface, was captured with ultrasound, and MT was measured using Image J. Independent samples t-tests were conducted to compare MT over the ulna and radius between climbers and controls. RESULTS: Climbers had an average of 2.44±1.24 years of experience, and had lower body fat percentages (19.14±6.99) than controls (30.02±7.6) (p<.001). BMI was similar for climbers and controls at 21.77±3.23 and 22.62±22.62kg/m2, respectively. Both ulnar and radial MT values were significantly higher in climbers, 4.23±.39cm and 2.32±.39cm (p<.001) respectively, and 3.61±.6cm and 1.84±.31cm in controls (p<.001). CONCLUSION: Despite a relatively low average climbing experience rock climbers had larger MT values than controls. The present study demonstrated that ultrasound can be used to detect differences in flexor MT in rock climbers compared to controls. Future studies should examine longitudinal changes in MT in climbers as they progress in training.