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Introduction: Puberty substantially alters the body's mechanical properties, neuromuscular control, and sex differences therein, likely contributing to increased, sex‐biased knee injury risk during adolescence. Female adolescents have higher risk for knee injuries than male adolescents of similar age engaging in similar physical activities, and much research has investigated sex differences in mechanical risk factors. However, few studies address the considerable variation in pubertal growth (timing, pace), knee mechanics, and injury susceptibility within sexes, or the impact of such growth variation on mechanical injury risk. Objectives: The present study tested for effects of variation in pubertal growth on established mechanical knee injury risk factors, examining relationships between and within sexes. Methods: Pubertal growth indices describing variation in the timing and rate of pubertal growth were developed using principal component analysis and auxological data from serial stature measurements. Linear mixed models were applied to evaluate relationships between these indices and knee mechanics during walking in a sample of adolescents. Results: Later developing female adolescents with slower pubertal growth had higher extension moments throughout stance, whereas earlier developers had higher valgus knee angles and moments. In male adolescents, faster and later growth were related to higher extension moments throughout gait. In both sexes, faster growers had higher internal rotation moments at foot‐strike. Conclusions: Pubertal growth variation has important effects on mechanical knee injury risk in adolescence, affecting females and males differently. Earlier developing females exhibit greater injury risk via frontal plane factors, whereas later/faster developing males have elevated risk via sagittal plane mechanisms. [ABSTRACT FROM AUTHOR]

Objective: To identify trajectories of ontogenetic change in the mandibular plane angle (MPA) and to describe the influence of sex and other factors on MPA during growth.Setting/sample: The data consisted of 7026 MPA measurements from lateral cephalographs representing longitudinal series from ages 6 to 21 for 728 individuals from the Craniofacial Growth Consortium Study (CGCS).Materials and Methods: Facial type was determined from MPA for each assessment, with the assessment closest to age 18 representing the adult facial type. The sample includes 366 males and 362 females, each with between 2 and 15 cephalographs. The mean number of cephalographs per individual is 10. Variation in childhood MPA (earliest assessment between 6 and 9 years of age) and adult MPA (closest assessment to age 18 between 15 and 21 years of age), and change in MPA from childhood to adulthood were compared by sex and adult facial type using ANOVA and post hoc t tests.Results: Mandibular plane angle decreased from childhood to adulthood in 92% of males and 81% of females, yet increased in 36% of males and 50% of females with the hyper-divergent adult facial type. Childhood MPA and overall change in MPA were significantly different by adult facial type.Conclusions: Adult facial type is associated with differences in childhood MPA and change in MPA during growth. There are multiple ontogenetic pathways by which an individual can achieve a normo-divergent adult facial type, and an individual's childhood MPA does not necessarily correspond to his or her adult facial type. [ABSTRACT FROM AUTHOR]

Objectives: To assess the potential of predicting adult facial types at different stages of mandibular development.Setting and Sample Population: A total of 941 participants from the Bolton-Brush, Denver, Fels, Iowa, Michigan and Oregon growth studies with longitudinal lateral cephalograms (total of 7166) between ages 6-21 years.Material and Methods: Each participant was placed into one of three facial types based on mandibular plane angle (MPA) from cephalograms taken closest to 18 years of age (range of 15-21 years): hypo-divergent (MPA < 28°), normo-divergent (28°≤ MPA ≤ 39°) and hyper-divergent (MPA > 39°). Cephalograms were categorized into 13 age groups 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 and 18-21. Twenty-three two-dimensional anatomical landmarks were digitized on the mandible and superimposed using generalized Procrustes analysis, which projects landmarks into a common shape space. Data were analysed within age categories using stepwise discriminant analysis to identify landmarks that distinguish adult facial types and by jackknife cross-validation to test how well young individuals can be reclassified into their adult facial types.Results: Although each category has multiple best discriminating landmarks among adult types, three landmarks were common across nearly all age categories: menton, gonion and articulare. Individuals were correctly classified better than chance, even among the youngest age category. Cross-validation rates improved with age, and hyper- and hypo-divergent groups have better reclassification rates than the normo-divergent group.Conclusions: The discovery of important indicators of adult facial type in the developing mandible helps improve our capacity to predict adult facial types at a younger age. [ABSTRACT FROM AUTHOR]

Background: Age at menarche impacts patterns of pubertal growth and skeletal development. These effects may carry over into variation in biomechanical profiles involved in sports-related traumatic and overuse knee injuries. The present study investigated whether age at menarche is a potential indicator of knee injury risk through its influence on knee biomechanics during normal walking.Objective: To test the hypothesis that earlier menarche is related to postpubertal biomechanical risk factors for knee injuries, including a wider, more immature gait base of support, and greater valgus knee angles and moments.Design: Cross-sectional observational study.Setting: University research facility.Participants: Healthy, postmenarcheal, adolescent girls.Methods: Age at menarche was obtained by recall questionnaire. Pubertal growth and anthropometric data were collected by using standard methods. Biomechanical data were taken from tests of walking gait at self-selected speed. Reflective marker position data were collected with a 3-dimensional quantitative motion analysis system, and 3 force plates recorded kinetic data.Main Outcome Measures: Age at menarche; growth and anthropometric measurements; base of support; static knee frontal plane angle; and dynamic knee frontal plane angles and moments during stance.Results: Earlier menarche was correlated significantly with abbreviated pubertal growth and postpubertal retention of immature traits, including a wider base of support. Earlier menarche and wider base of support were both correlated with more valgus static knee angles, more valgus knee abduction angles and moments at foot-strike, and a more valgus peak knee abduction angle during stance. Peak knee abduction moment during stance was not correlated with age at menarche or base of support.Conclusions: Earlier menarche and its effects on growth are associated with retention of a relatively immature gait base of support and a tendency for static and dynamic valgus knee alignment. This biomechanical profile may put girls with earlier menarche at greater risk for sports-related knee injuries.Level Of Evidence: Not applicable. [ABSTRACT FROM AUTHOR]

Objective Bariatric surgery is an effective method for acute weight loss. While the impact of bariatric surgery on general medical conditions (e.g., type 2 diabetes) is well documented, few studies focus on physical functional outcomes following weight-loss induced by bariatric surgery. Design and Methods We report on 50 women aged 20-74 scheduled for Roux-en-Y gastric bypass (RYGB) procedure who were enrolled for a prospective 1-year study. Height, weight, and waist circumference were recorded preoperatively and at 6 and 12 months, postoperatively. To track musculoskeletal/physical function changes, the timed-get-up-and-go (TGUG) and short-form health survey-36 (SF-36) and short musculoskeletal function assessment (SFMA) questionnaires were administered. Results Patients had significant weight loss and functional improvement. At 1 year mean weight loss was 48.5 kg and mean TGUG improvement was 3.1 s. SMFA and SF-36 also showed improvement in functional components with weight loss at 6 months and 1-year post surgery. Significant associations were observed between TGUG and SMFA measures at all time points. Final weight at 1 year post bariatric surgery was also significantly correlated with most functional outcomes and changes in these outcomes. Partial correlations controlling for age revealed additional associations between body weight and functional outcomes, especially at the 6-month visit. Conclusion Our results suggest that significant rapid weight loss, such as that attained by bariatric surgery, acutely improves musculoskeletal function in morbidly obese patients. Additionally, for patients with musculoskeletal disease or injury, weight loss resulting from bariatric surgery may serve as an adjunct for improving global functional outcome, and enhancing the rehabilitation potential. [ABSTRACT FROM AUTHOR]

Growth, development, and decline of the human skeleton are of central importance to physical anthropology. All processes of skeletal growth (longitudinal growth as well as gains and losses of bone mass) are subjected to environmental and genetic influences. These influences, and their relative contributions to the phenotype, can be asserted at any stage of life. We present here the gross phenotypic and genetic landscapes of four skeletal traits, and show how they vary across the life span. Phenotypic sex differences are found in bone diameter and cortical index (a ratio of cortical thickness over bone diameter) at a very early age and continue throughout most of life. Sexual dimorphism in summed cortical thickness and bone length, however, is not evident until shortly after the pubertal growth spurt. Genetic contributions (heritability) to these skeletal phenotypes are generally moderate to high. Bone length and bone diameter (which both scale with body size) tend to have the highest heritability, with heritability of bone length fairly stable across ages (with a notable dip in early childhood) and that of bone diameter peaking in early childhood. The bone traits summed cortical thickness and cortical index that may better reflect bone mass, a more plastic phenomenon, have slightly lower genetic influences, on average. Results from our phenotypic and genetic landscapes serve three key purposes: 1) demonstration of the integrated nature of the genetic and environmental underpinnings of skeletal form, 2) identification of periods of bone's relative sensitivity to genetic and environmental influences, 3) and stimulation of hypotheses predicting the effects of exposure to environmental variables on the skeleton, given variation in the underlying genetic architecture. Am J Phys Anthropol, 2013. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Physical anthropological research was codified in the United States with the creation of the American Association of Physical Anthropology (AAPA) in 1929. That same year, a study began in yellow springs, Ohio, with a goal of identifying 'what makes people different.' The approach used to answer that question was to study the growth and development of Homo sapiens. The resulting study, the Fels Longitudinal Study, is currently the longest continuous study of human growth and development in the world. Although the AAPA and the Fels Longitudinal Study have existed as separate entities for more than 80 years now, it is not surprising, given the relationship between anatomical and developmental research, there has been considerable overlap between the two. As the field of physical anthropology has blossomed to include subdisciplines such as forensics, genetics, primatology, as well as sophisticated statistical methodologies, the importance of growth and development research has escalated. Although current Fels Longitudinal Study research is largely directed at biomedical questions, virtually all findings are relevant to physical anthropology, providing insights into basic biological processes and life history parameters. Some key milestones from the early years of the AAPA and the Fels Longitudinal Study are highlighted here that address growth and development research in physical anthropology. These are still held as fundamental concepts that underscore the importance of this line of inquiry, not only across the subdisciplines of physical anthropology, but also among anthropological, biological, and biomedical inquiries. Am J Phys Anthropol, 2013. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Measures of maturity provide windows into the timing and tempo of childhood growth and maturation. Delayed maturation in a single child, or systemically in a population, can result from either genetic or environmental factors. In terms of the skeleton, delayed maturation may result in short stature or indicate another underlying issue. Thus, prediction of the timing of a maturational spurt is often desirable in order to determine the likelihood that a child will catch up to their chronological age peers. Serial data from the Fels Longitudinal Study were used to predict future skeletal age conditional on current skeletal age and to predict the timing of maturational spurts. For children who were delayed relative to their chronological age peers, the likelihood of catch-up maturation increased through the average age of onset of puberty and decreased prior to the average age of peak height velocity. For boys, the probability of an imminent maturational spurt was higher for those who were less mature. For girls aged 11 to 13 years, however, this probability was higher for those who were more mature, potentially indicating the presence of a skeletal maturation plateau between multiple spurts. The prediction model, available on the web, is most relevant to children of European ancestry living in the Midwestern US. Our model may also provide insight into the tempo of maturation for children in other populations, but must be applied with caution if those populations are known to have high burdens of environmental stressors not typical of the Midwestern US. Am J Phys Anthropol, 2013. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The article describes a study which analyzed data from repeated grip measurements from 498 male and 533 female subjects aged 18-96 years old using Bayesian statistical methods in order to model the trajectory of adult grip strength. The potential risk factors that may possibly influence that trajectory are also investigated. Findings show that men and women attain peak grip strength as they use their dominant hand grip strength trajectory at around 36 years old. Women begin to decline sooner but men lose their grip faster as the decline starts.