ABSTRACT
ABSTRACT: Redinger, AL, Russell, JL, Allen, SMF, and Baker, BS. Height restrictions for dual-energy x-ray absorptiometry: what are our options for body composition and bone health precision? J Strength Cond Res XX(X): 000-000, 2024-Dual-energy X-ray absorptiometry (DXA) is commonly used for testing athlete's body composition, but many athletes are too tall. The first aim was to assess the viability of combining upper- and lower-body regions of interest (ROI), creating a combined scan for tall athletes who do not fit on the table and second, to provide practical solutions to DXA users who routinely scan tall athletes. Sixty subjects (34.8 ± 11.9 years; 171 ± 9 cm) completed 2 total-body DXA scans for baseline precision testing, using GE Lunar Prodigy (LP) or Hologic Horizon A (HA) models. Next, an upper body ROI from the skull to the distal femoral condyles was combined with a flipped scan (feet-to-head) ROI encompassing the proximal tibial plateau to the distal foot. Soft and bone tissue coefficient of variance (CV%) were calculated between the baseline scans and for the newly combined ROI scan. The combined ROI scan added 0.25-0.63% and 0.01-4.35% error rates for the LP and HA, respectively. An exploratory assessment of a GE Lunar iDXA demonstrated results similar to the HA with 4%+ error. The combined ROI scan is a user-friendly and precise method for older LP systems adding less than 1% error; however, newer DXA systems cannot use the stitched scan technique. Coaches and practitioners who use newer DXAs must prioritize consistently using the same boney landmarks (head, jaw, or feet) and ROI heights to provide precise longitudinal assessments of tall athletes' bone and body composition, until larger DXA tables become available.
ABSTRACT
Military personnel experience elevated bone injury incidence, partly due to arduous and repetitive training. Non-traditional High-Intensity Interval Training-style (HIIT) may benefit pre-enlisted Reserve Officer Training Corps (ROTC) cadet's musculoskeletal health and performance prior to military service. This study investigated 16 ROTC (n = 12 males; n = 4 females) and 15 physically active sex-, age-, and body mass-matched Controls' musculoskeletal health and performance from November to April. Total body, lumbar spine, and dual- hip dual-energy X-ray absorptiometry scans and 4%, 38%, 66% tibial peripheral quantitative computed tomography scans, blood draws (serum sclerostin and parathyroid hormone), and maximal muscle strength and aerobic capacity testing were completed. From November to April, ROTC improved bone density (DXA) of the dominant total hip and greater trochanter and non-dominant greater trochanter and 38% and 66% tibial total volumetric and cortical bone density (pQCT) similarly or more than Controls (all p ≤ 0.049). From November to April, ROTC also improved bench and leg press, and peak aerobic capacity (all p ≤ 0.013). From November to January, serum sclerostin increased (p ≤ 0.007) and remained elevated through April, while parathyroid hormone was unchanged. HIIT-style training induced positive musculoskeletal adaptations, suggesting it may be an excellent pre-service training modality for this injury prone group.
