data have commonly been provided from a small number of cadaver segmentation studies, 5 limiting the applicability of the data across different populations. Dual-energy x-ray absorptiometry (DXA) is a valid and reliable method for analyzing body composition 6 – 9 and estimating inertial
Danielle L. Gyemi, Charles Kahelin, Nicole C. George and David M. Andrews
Amy R. Lewis, William S.P. Robertson, Elissa J. Phillips, Paul N. Grimshaw and Marc Portus
’Brien et al 29 used magnetic resonance imaging scans to obtain muscle volume, which was divided by optimal fascicle length at the angle of peak force, as measured using ultrasound images. Alternatively, this has been achieved using dual-energy X-ray absorptiometry (DXA) and computed tomography. However
Zachary Merrill, Grace Bova, April Chambers and Rakié Cham
body mass index (BMI) influence parameters, particularly in large segments such as the thigh and trunk. 16 Thus, the current study, using in vivo dual-energy X-ray absorptiometry (DXA) data, aims to objectively quantify the impact of trunk segmentation method on trunk BSPs in normal weight and morbidly
Silvia Gonçalves Ricci Neri, André Bonadias Gadelha, Ana Luiza Matias Correia, Juscélia Cristina Pereira, Ana Cristina de David and Ricardo M. Lima
measured by dual-energy x-ray absorptiometry (DXA) (General Electric-GE model 8548 BX1L, 2005, DPX lunar type, Encore 2010 software, Rommelsdorf, Germany), according to procedures described elsewhere. 21 Briefly, subjects laid face up on the DXA table with the body carefully centered. The software
Bailey Peck, Timothy Renzi, Hannah Peach, Jane Gaultney and Joseph S. Marino
. *Significant effect of sport ( P < .05). Dual-Energy X-ray Absorptiometry A whole-body and regional dual-energy X-ray absorptiometry (DEXA; GE Lunar Primo Prodigy, Madison, WI; enCORE™ 2011 software, version 15) scan was performed to measure percent body fat. 14 Color mapping indicated areas of high and low
Bernadette L. Foster, Jeff W. Walkley and Viviene A. Temple
The purpose of this study was to describe and compare the bone mineral density of women with intellectual disability (WID) and a comparison group (WOID) matched for age and sex. One hundred and five women, ages 21 to 39, M = 29, were tested for their bone mineral density levels at the lumbar spine and three sites of the proximal femur using dual energy X-ray absorptiometry. No significant difference between groups existed (λ = 0.94, F(4, 98) = 1.68, p = .16, η2 = .06); however, one-sample t tests revealed that bone mineral density for the WID group (n = 35) was significantly lower than zero at the Ward’s triangle (p < .01) and the lumbar spine (p < .05). Approximately one-quarter of WID had low bone density at these two sites, suggesting that WID may be at risk of osteoporotic fracture as they age.
Jason Wicke and Genevieve A. Dumas
Body segment inertial parameters are required as input parameters when the kinetics of human motion is to be analyzed. However, owing to interindividual differences in body composition, noninvasive inertial estimates are problematic. Dual-energy x-ray absorptiometry (DXA) is a relatively new imaging approach that can provide cost- and time-effective means for estimating these parameters with minimal exposure to radiation. With the introduction of a new generation of DXA machines, utilizing a fan-beam configuration, this study examined their accuracy as well as a new interpolative data-reduction process for estimating inertial parameters. Specifically, the inertial estimates of two objects (an ultra-high molecular density plastic rod and an animal specimen) and 50 participants were obtained. Results showed that the fan-beam DXA, along with the new interpolative data-reduction process, provided highly accurate estimates (0.10–0.39%). A greater variance was observed in the center of mass location and moment of inertia estimates, likely as a result of the course end-point location (1.31 cm). However, using a midpoint interpolation of the end-point locations, errors in the estimates were greatly reduced for the center of mass location (0.64–0.92%) and moments of inertia (–0.23 to –0.48%).
April J. Chambers, Alison L. Sukits, Jean L. McCrory and Rakié Cham
Age, obesity, and gender can have a significant impact on the anthropometrics of adults aged 65 and older. The aim of this study was to investigate differences in body segment parameters derived using two methods: (1) a dual-energy x-ray absorptiometry (DXA) subject-specific method (Chambers et al., 2010) and (2) traditional regression models (de Leva, 1996). The impact of aging, gender, and obesity on the potential differences between these methods was examined. Eighty-three healthy older adults were recruited for participation. Participants underwent a whole-body DXA scan (Hologic QDR 1000/W). Mass, length, center of mass, and radius of gyration were determined for each segment. In addition, traditional regressions were used to estimate these parameters (de Leva, 1996). A mixed linear regression model was performed (α = 0.05). Method type was significant in every variable of interest except forearm segment mass. The obesity and gender differences that we observed translate into differences associated with using traditional regressions to predict anthropometric variables in an aging population. Our data point to a need to consider age, obesity, and gender when utilizing anthropometric data sets and to develop regression models that accurately predict body segment parameters in the geriatric population, considering gender and obesity.
Hawley Chase Almstedt and Zakkoyya H. Lewis
Intermittent pneumatic compression (IPC) is a common therapeutic modality used to reduce swelling after trauma and prevent thrombosis due to postsurgical immobilization. Limited evidence suggests that IPC may decrease the time needed to rehabilitate skeletal fractures and increase bone remodeling.
To establish feasibility and explore the novel use of a common therapeutic modality, IPC, on bone mineral density (BMD) at the hip of noninjured volunteers.
University research laboratory.
Noninjured participants (3 male, 6 female) completed IPC treatment on 1 leg 1 h/d, 5 d/wk for 10 wk. Pressure was set to 60 mm Hg when using the PresSsion and Flowtron Hydroven compression units.
Main Outcome Measures:
Dual-energy X-ray absorptiometry was used to assess BMD of the hip in treated and nontreated legs before and after the intervention. Anthropometrics, regular physical activity, and nutrient intake were also assessed.
The average number of completed intervention sessions was 43.4 (± 3.8) at an average duration of 9.6 (± 0.8) wk. Repeated-measures analysis of variance indicated a significant time-by-treatment effect at the femoral neck (P = .023), trochanter (P = .027), and total hip (P = .008). On average, the treated hip increased 0.5–1.0%, while the nontreated hip displayed a 0.7–1.9% decrease, depending on the bone site.
Results of this exploratory investigation suggest that IPC is a therapeutic modality that is safe and feasible for further investigation on its novel use in optimizing bone health.
Michael R. Esco, Brett S. Nickerson, Sara C. Bicard, Angela R. Russell and Phillip A. Bishop
The purpose of this investigation was to evaluate measurements of body-fat percentage (BF%) in 4 body-mass-index- (BMI) -based equations and dual-energy X-ray absorptiometry (DXA) in individuals with Down syndrome (DS). Ten male and 10 female adults with DS volunteered for this study. Four regression equations for estimating BF% based on BMI previously developed by Deurenberg et al. (DEBMI-BF%), Gallagher et al. (GABMI-BF%), Womersley & Durnin (WOBMI-BF%), and Jackson et al. (JABMI-BF%) were compared with DXA. There was no significant difference (p = .659) in mean BF% values between JABMI-BF% (BF% = 40.80% ± 6.3%) and DXA (39.90% ± 11.1%), while DEBMI-BF% (34.40% ± 9.0%), WOBMI-BF% (35.10% ± 9.4%), and GABMI-BF% (35.10% ± 9.4%) were significantly (p < .001) lower. The limits of agreement (1.96 SD of the constant error) varied from 9.80% to 16.20%. Therefore, BMI-based BF% equations should not be used in individuals with DS.