Browsing by Subject "Anthropometry"
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Item Open Access Darwinius masillae is a strepsirrhine--a reply to Franzen et al. (2009).(Journal of human evolution, 2010-11) Williams, Blythe A; Kay, Richard F; Kirk, E Christopher; Ross, Callum FItem Open Access Energy recovery in individuals with knee osteoarthritis.(Osteoarthritis Cartilage, 2014-06) Sparling, TL; Schmitt, D; Miller, CE; Guilak, F; Somers, TJ; Keefe, FJ; Queen, RMOBJECTIVE: Pathological gaits have been shown to limit transfer between potential (PE) and kinetic (KE) energy during walking, which can increase locomotor costs. The purpose of this study was to examine whether energy exchange would be limited in people with knee osteoarthritis (OA). METHODS: Ground reaction forces during walking were collected from 93 subjects with symptomatic knee OA (self-selected and fast speeds) and 13 healthy controls (self-selected speed) and used to calculate their center of mass (COM) movements, PE and KE relationships, and energy recovery during a stride. Correlations and linear regressions examined the impact of energy fluctuation phase and amplitude, walking velocity, body mass, self-reported pain, and radiographic severity on recovery. Paired t-tests were run to compare energy recovery between cohorts. RESULTS: Symptomatic knee OA subjects displayed lower energetic recovery during self-selected walking speeds than healthy controls (P = 0.0018). PE and KE phase relationships explained the majority (66%) of variance in recovery. Recovery had a complex relationship with velocity and its change across speeds was significantly influenced by the self-selected walking speed of each subject. Neither radiographic OA scores nor subject self-reported measures demonstrated any relationship with energy recovery. CONCLUSIONS: Knee OA reduces effective exchange of PE and KE, potentially increasing the muscular work required to control movements of the COM. Gait retraining may return subjects to more normal patterns of energy exchange and allow them to reduce fatigue.Item Open Access Enhanced fitness: a randomized controlled trial of the effects of home-based physical activity counseling on glycemic control in older adults with prediabetes mellitus.(Journal of the American Geriatrics Society, 2012-09) Morey, MC; Pieper, CF; Edelman, DE; Yancy Jr, WS; Green, JB; Lum, H; Peterson, MJ; Sloane, R; Cowper, PA; Bosworth, HB; Huffman, KM; Cavanaugh, JT; Hall, KS; Pearson, MP; Taylor, GAOBJECTIVE: To determine whether a home-based multicomponent physical activity counseling (PAC) intervention is effective in reducing glycemic measures in older outpatients with prediabetes mellitus. METHODS: Controlled clinical trial. METHODS: Primary care clinics of the Durham Veterans Affairs (VA) Medical Center between September 29, 2008, and March 25, 2010. METHODS: Three hundred two overweight (body mass index 25-45 kg/m(2) ), older (60-89) outpatients with impaired glucose tolerance (fasting blood glucose 100-125 mg/dL, glycosylated hemoglobin (HbA1c)Item Open Access Hip extensor mechanics and the evolution of walking and climbing capabilities in humans, apes, and fossil hominins.(Proceedings of the National Academy of Sciences of the United States of America, 2018-04-02) Kozma, Elaine E; Webb, Nicole M; Harcourt-Smith, William EH; Raichlen, David A; D'Août, Kristiaan; Brown, Mary H; Finestone, Emma M; Ross, Stephen R; Aerts, Peter; Pontzer, HermanThe evolutionary emergence of humans' remarkably economical walking gait remains a focus of research and debate, but experimentally validated approaches linking locomotor capability to postcranial anatomy are limited. In this study, we integrated 3D morphometrics of hominoid pelvic shape with experimental measurements of hip kinematics and kinetics during walking and climbing, hamstring activity, and passive range of hip extension in humans, apes, and other primates to assess arboreal-terrestrial trade-offs in ischium morphology among living taxa. We show that hamstring-powered hip extension during habitual walking and climbing in living apes and humans is strongly predicted, and likely constrained, by the relative length and orientation of the ischium. Ape pelves permit greater extensor moments at the hip, enhancing climbing capability, but limit their range of hip extension, resulting in a crouched gait. Human pelves reduce hip extensor moments but permit a greater degree of hip extension, which greatly improves walking economy (i.e., distance traveled/energy consumed). Applying these results to fossil pelves suggests that early hominins differed from both humans and extant apes in having an economical walking gait without sacrificing climbing capability. Ardipithecus was capable of nearly human-like hip extension during bipedal walking, but retained the capacity for powerful, ape-like hip extension during vertical climbing. Hip extension capability was essentially human-like in Australopithecus afarensis and Australopithecus africanus, suggesting an economical walking gait but reduced mechanical advantage for powered hip extension during climbing.Item Open Access Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa.(eLife, 2015-09) Berger, Lee R; Hawks, John; de Ruiter, Darryl J; Churchill, Steven E; Schmid, Peter; Delezene, Lucas K; Kivell, Tracy L; Garvin, Heather M; Williams, Scott A; DeSilva, Jeremy M; Skinner, Matthew M; Musiba, Charles M; Cameron, Noel; Holliday, Trenton W; Harcourt-Smith, William; Ackermann, Rebecca R; Bastir, Markus; Bogin, Barry; Bolter, Debra; Brophy, Juliet; Cofran, Zachary D; Congdon, Kimberly A; Deane, Andrew S; Dembo, Mana; Drapeau, Michelle; Elliott, Marina C; Feuerriegel, Elen M; Garcia-Martinez, Daniel; Green, David J; Gurtov, Alia; Irish, Joel D; Kruger, Ashley; Laird, Myra F; Marchi, Damiano; Meyer, Marc R; Nalla, Shahed; Negash, Enquye W; Orr, Caley M; Radovcic, Davorka; Schroeder, Lauren; Scott, Jill E; Throckmorton, Zachary; Tocheri, Matthew W; VanSickle, Caroline; Walker, Christopher S; Wei, Pianpian; Zipfel, BernhardHomo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa.Item Open Access Morphometric panel regression equations for predicting body mass in immature humans.(American journal of physical anthropology, 2018-05) Yapuncich, Gabriel S; Churchill, Steven E; Cameron, Noël; Walker, Christopher SOBJECTIVES:Predicting body mass is a frequent objective of several anthropological subdisciplines, but there are few published methods for predicting body mass in immature humans. Because most reference samples are composed of adults, predicting body mass outside the range of adults requires extrapolation, which may reduce the accuracy of predictions. Prediction equations developed from a sample of immature humans would reduce extrapolation for application to small-bodied target individuals, and should have utility in multiple predictive contexts. MATERIALS AND METHODS:Here, we present two novel body mass prediction equations derived from 3468 observations of stature and bi-iliac breadth from a large sample of immature humans (n = 173) collected in the Harpenden Growth Study. Prediction equations were generated using raw and natural log-transformed data and modeled using panel regression, which accounts for serial autocorrelation of longitudinal observations. Predictive accuracy was gauged with a global sample of human juveniles (n = 530 age- and sex-specific annual means) and compared to the performance of the adult morphometric prediction equation previously identified as most accurate for human juveniles. RESULTS:While the raw data panel equation is only slightly more accurate than the adult equation, the logged data panel equation generates very accurate body mass predictions across both sexes and all age classes of the test sample (mean absolute percentage prediction error = 2.47). DISCUSSION:The logged data panel equation should prove useful in archaeological, forensic, and paleontological contexts when predictor variables can be measured with confidence and are outside the range of modern adult humans.Item Open Access Reference data on in vitro anatomy and indentation response of tissue layers of musculoskeletal extremities.(Scientific data, 2020-01) Schimmoeller, Tyler; Neumann, Erica E; Owings, Tammy M; Nagle, Tara F; Colbrunn, Robb W; Landis, Benjamin; Jelovsek, J Eric; Hing, Tod; Ku, Joy P; Erdemir, AhmetThe skin, fat, and muscle of the musculoskeletal system provide essential support and protection to the human body. The interaction between individual layers and their composite structure dictate the body's response during mechanical loading of extremity surfaces. Quantifying such interactions may improve surgical outcomes by enhancing surgical simulations with lifelike tissue characteristics. Recently, a comprehensive tissue thickness and anthropometric database of in vivo extremities was acquired using a load sensing instrumented ultrasound to enhance the fidelity of advancing surgical simulations. However detailed anatomy of tissue layers of musculoskeletal extremities was not captured. This study aims to supplement that database with an enhanced dataset of in vitro specimens that includes ultrasound imaging supported by motion tracking of the ultrasound probe and two additional full field imaging modalities (magnetic resonance and computed tomography). The additional imaging datasets can be used in conjunction with the ultrasound/force data for more comprehensive modeling of soft tissue mechanics. Researchers can also use the image modalities in isolation if anatomy of legs and arms is needed.Item Open Access Reference data on thickness and mechanics of tissue layers and anthropometry of musculoskeletal extremities.(Scientific data, 2018-09) Neumann, Erica E; Owings, Tammy M; Schimmoeller, Tyler; Nagle, Tara F; Colbrunn, Robb W; Landis, Benjamin; Jelovsek, J Eric; Wong, Mike; Ku, Joy P; Erdemir, AhmetMusculoskeletal extremities exhibit a multi-layer tissue structure that is composed of skin, fat, and muscle. Body composition and anthropometric measurements have been used to assess health status and build anatomically accurate biomechanical models of the limbs. However, comprehensive datasets inclusive of regional tissue anatomy and response under mechanical manipulation are missing. The goal of this study was to acquire and disseminate anatomical and mechanical data collected on extremities of the general population. An ultrasound system, instrumented with a load transducer, was used for in vivo characterization of skin, fat, and muscle thicknesses in the extremities of 100 subjects at unloaded (minimal force) and loaded (through indentation) states. For each subject, the unloaded and loaded state provided anatomic tissue layer measures and tissue indentation response for 48 and 8 regions, respectively. A publicly available web-based system has been used for data management and dissemination. This comprehensive database will provide the foundation for comparative studies in regional musculoskeletal composition and improve visual and haptic realism for computational models of the limbs.Item Open Access Small-bodied humans from Palau, Micronesia.(PLoS One, 2008-03-12) Berger, Lee R; Churchill, Steven E; De Klerk, Bonita; Quinn, Rhonda LUNLABELLED: Newly discovered fossil assemblages of small bodied Homo sapiens from Palau, Micronesia possess characters thought to be taxonomically primitive for the genus Homo. BACKGROUND: Recent surface collection and test excavation in limestone caves in the rock islands of Palau, Micronesia, has produced a sizeable sample of human skeletal remains dating roughly between 940-2890 cal ybp. PRINCIPLE FINDINGS: Preliminary analysis indicates that this material is important for two reasons. First, individuals from the older time horizons are small in body size even relative to "pygmoid" populations from Southeast Asia and Indonesia, and thus may represent a marked case of human insular dwarfism. Second, while possessing a number of derived features that align them with Homo sapiens, the human remains from Palau also exhibit several skeletal traits that are considered to be primitive for the genus Homo. SIGNIFICANCE: These features may be previously unrecognized developmental correlates of small body size and, if so, they may have important implications for interpreting the taxonomic affinities of fossil specimens of Homo.Item Open Access The Prevalence and Social Determinants of Exclusive Breastfeeding and Implications for Infant Growth in Rural Haiti: A Mixed-Methods Study(2015) Zalla, LaurenBackground: While exclusive breastfeeding is known to protect against infant morbidity and mortality, its effects on growth are not well understood. This study aimed to identify individual and household characteristics associated with exclusive breastfeeding in a rural population in Haiti, and to test the association between duration of exclusive breastfeeding and infant height-for-age (HAZ), weight-for-height (WHZ) and weight-for-age (WAZ). In addition, qualitative methods were employed to identify community perceptions of exclusive breastfeeding and barriers to its adoption. Methods: A household survey was conducted to assess breastfeeding practices and maternal and infant nutritional status in rural Léogâne Commune (N=119), and linear regression was used to estimate the associations between duration of exclusive breastfeeding and infant HAZ, WHZ and WAZ. In addition, 32 community health workers completed a written survey and participated in focus group discussions of the benefits of exclusive breastfeeding and barriers to its adoption in their communities. Results: Survey variables associated with shorter duration of exclusive breastfeeding (α=0.10) included preterm birth, late initiation of breastfeeding, maternal employment and the practice of giving infants tea. The community health workers identified several additional socio-cultural and institutional barriers to exclusive breastfeeding in their communities, including the advice of community elders, poverty and food insecurity. Duration of exclusive breastfeeding was positively associated with both HAZ and WAZ (α=0.05), but not significantly associated with WHZ. Conclusions: This study provides evidence that duration of exclusive breastfeeding is positively associated with infant height-for-age and weight-for-age in a rural, resource-limited setting, suggesting that promotion of exclusive breastfeeding may be effective as part of a package of interventions to prevent underweight and stunting among infants at risk of malnutrition. In addition, qualitative findings suggest that efforts to promote exclusive breastfeeding should pay attention to underlying issues of poverty and food security, and the effects of the physical and social environment on the choices women make regarding infant feeding in Haiti.