Hip width and metabolic energy expenditure of abductor muscles.

Despite a paucity of physiological evidence, simplistic biomechanical analyses have led researchers to assume that humans who have wider hips use more energy to walk. Pitting biomechanical first principles against physiological data has led to little deepening of our understanding of bipedalism and its evolution. Both approaches, however, use proxies for the energy used by muscles.

Sensitivity of musculoskeletal models to variation in muscle architecture parameters.

Musculoskeletal models, like all theoretical models of physical processes, depend on the assumptions needed to construct the model. For musculoskeletal models, these assumptions include, among other things, the kinematic data, the kinetic data and the muscle parameters. The former (dynamic) data can be acquired relatively easily from living subjects, but the latter are usually based on limited information, frequently determined from cadaver studies performed on elderly individuals.

Foot morphology influences the change in arch index between standing and walking conditions.

Human foot morphology has been of interest to anatomists, clinicians, and paleontologists for a century due to its importance in bipedal walking. Foot shape changes as forces move through it from the body to the substrate. Although the arch of the foot has been extensively evaluated, the role of foot morphology in the change of the arch height in walking is less explored.

A review of musculoskeletal modelling of human locomotion.

Locomotion through the environment is important because movement provides access to key resources, including food, shelter and mates. Central to many locomotion-focused questions is the need to understand internal forces, particularly muscle forces and joint reactions. Musculoskeletal modelling, which typically harnesses the power of inverse dynamics, unites experimental data that are collected on living subjects with virtual models of their morphology.

Consistent inconsistencies in braking: a spatial analysis.

The dynamic system that is the bipedal body in motion is of interest to engineers, clinicians and biological anthropologists alike. Spatial statistics is more familiar to public health researchers as a way of analysing disease clustering and spread; nonetheless, this is a practical approach to the two-dimensional topography of the foot. We quantified the clustering of the centre of pressure (CoP) on the foot for peak braking and propulsive vertical ground reaction forces (GRFs) over multiple, contiguous steps to assess the consistency of the location of peak forces on the foot during walking.

Anthroengineering: an independent interdisciplinary field.

In recent decades, funding agencies, institutes and professional bodies have recognized the profound benefits of transdisciplinarity in tackling targeted research questions. However, once questions are answered, the previously abundant support often dissolves. As such, the long-term benefits of these transdisciplinary approaches are never fully achieved.

Walking Speed Alters Barefoot Gait Coordination and Variability.

Using the dynamic system approach, we examined the pattern and variability of inter-joint coordination in barefoot and shod walking in 20 women at three speeds: SLOW, FAST, and comfortable walking speed (CWS). We found that barefoot and shod walking used different coordination strategies to cope with increasing walking speed. As walking speed increased, ankle-knee coordination patterns between shod and barefoot became less different ( < 0.

Muscle forces and the demands of human walking.

Reconstructing the locomotor behavior of extinct animals depends on elucidating the principles that link behavior, function, and morphology, which can only be done using extant animals. Within the human lineage, the evolution of bipedalism represents a critical transition, and evaluating fossil hominins depends on understanding the relationship between lower limb forces and skeletal morphology in living humans. As a step toward that goal, here we use a musculoskeletal model to estimate forces in the lower limb muscles of ten individuals during walking.

Effect of standing and sitting positions on energy expenditure in people with transtibial amputation compared to age- and sex-matched controls.

Background: Energy expenditure (EE) is often greater in people with lower-limb amputation, compared with healthy controls, because of the biomechanical compensations needed to walk with a prosthesis. Compensatory movements are required to stand with a prosthesis; however, little is known about whether standing with a prosthesis also requires greater EE.

Objective: The goal of this study was to examine the effect of standing and sitting positions on EE in people with transtibial amputation and matched controls.

Radiographic measurements of the talus and calcaneus in the adult pes planus foot type.

Objective: A distinctive feature of the modern human foot is the presence of a medial longitudinal arch when weight-bearing. Although the talus and calcaneus play a major role in the structure and function of the human foot, the association between the morphology of these bones and longitudinal arch height has not been fully investigated. A better understanding of this relationship may assist in the interpretation of pedal remains of fossil hominins, where features of the foot and ankle morphology have been described as providing evidence for the presence of a longitudinal arch.

Estimating the in vivo location of the talus from external surface landmarks.

Objectives: Finite element analysis has gained popularity in anthropological research to connect morphological form to measurable function but requires that loads are applied at appropriate anatomical locations. This is challenging for the ankle because the joint surfaces are not easily determined given their deep anatomical location. While the location of the talonavicular and subtalar joints can be directly determined via medical imaging, regression equations are a common, less invasive method to estimate joint locations from surface anatomy.

The Relationship Between Angular Osteologic and Radiographic Measurements of the Human Talus and Calcaneus.

Background: Radiographic imaging of the foot is commonly performed when medical evaluation is indicated. Angular measurements between bones may be assessed as part of the examination for trauma and foot biomechanics. However, angular relationships between surfaces of the physical bone as they compare with the bone's radiographic image has had limited investigation.

The Effect of Parity on Age-Related Degenerative Changes in Sagittal Balance.

Study Design: Retrospective cohort study.

Objective: Evaluate the effects of parity (number of births) on measures of sagittal posture in elderly women. The long-term objective of this study is to identify and mitigate factors contributing to age-related postural deformity in older adults.

Development of Pelvic Incidence and Lumbar Lordosis in Children and Adolescents.

Pelvic incidence (PI) is a measure of the sagittal orientation of the sacrum relative to the acetabula and is not dependent on posture. In asymptomatic adults, PI correlates with lumbar lordosis. Lumbar lordosis is shown to increase with age following the onset of unassisted bipedal locomotion in children, but to what extent PI changes in relation to lumbar lordosis during skeletal maturation is unclear.

Energy expenditure in people with transtibial amputation walking with crossover and energy storing prosthetic feet: A randomized within-subject study.

Background: Energy storing feet are unable to reduce the energy required for normal locomotion among people with transtibial amputation. Crossover feet, which incorporate aspects of energy storing and running specific feet, are designed to maximize energy return while providing stability for everyday activities.

Research Question: Do crossover prosthetic feet reduce the energy expenditure of walking across a range of speeds, when compared with energy storing feet among people with transtibial amputation due to non-dysvascular causes?

Methods: A randomized within-subject study was conducted with a volunteer sample of twenty-seven adults with unilateral transtibial amputation due to non-dysvascular causes.

Young's Modulus and Load Complexity: Modeling Their Effects on Proximal Femur Strain.

Finite element analysis (FEA) is a powerful tool for evaluating questions of functional morphology, but the application of FEA to extant or extinct creatures is a non-trivial task. Three categories of input data are needed to appropriately implement FEA: geometry, material properties, and boundary conditions. Geometric data are relatively easily obtained from imaging techniques, but often material properties and boundary conditions must be estimated.

Laboratory- and community-based health outcomes in people with transtibial amputation using crossover and energy-storing prosthetic feet: A randomized crossover trial.

Unlabelled: Contemporary prosthetic feet are generally optimized for either daily or high-level activities. Prosthesis users, therefore, often require multiple prostheses to participate in activities that span a range of mobility. Crossover feet (XF) are designed to increase the range of activities that can be performed with a single prosthesis.

Gastrocnemius or Achilles Lengthening at Time of Trauma Fixation.

Gastrocnemius equinus is a frequent comorbidity with traumatic injuries of the foot and ankle. Gastrocnemius lengthening at the time of definitive treatment facilitates obtaining and maintaining an anatomic reduction of the injury. The lengthening procedure is accomplished in 5 steps and results in fewer long-term, problematic sequelae.

Minimal energetic expenditure of women walking burdened on gradients in urban environments.

Objectives: The objective is to understand the walking energy expenditure of women in urban environments (i.e., over-ground), using mass, velocity, gradient (incline and decline), and burden as predictors.

Morphological and postural sexual dimorphism of the lumbar spine facilitates greater lordosis in females.

Previous work suggests females are evolutionarily adapted to have greater lumbar lordosis than males to aid in pregnancy load-bearing, but no consensus exists. To explore further sex-differences in the lumbar spine, and to understand contradictions in the literature, we conducted a cross-sectional retrospective study of sex-differences in lumbar spine morphology and sacral orientation. In addition, our sample includes data for separate standing and supine samples of males and females to examine potential sex-differences in postural loading on lumbosacral morphology.

Joint-Preserving Osteotomies for Malaligned Intraarticular Calcaneal Fractures.

Intraarticular calcaneal fracture treatments that result in malalignment often require reconstructive surgery. Seven cases are used to demonstrate the intricacies of reconstructive case management. Reestablishment of calcaneal height, length, orientation, and position relative to the other tarsals is necessary to reestablish appropriate foot function.

Incidence of Preoperative Deep Vein Thrombosis in Calcaneal Fractures.

Objectives: This study examined the incidence and risk factors of preoperative deep vein thrombosis (DVT) in patients presenting to an outpatient setting with an isolated calcaneal fracture.

Design: Retrospective chart review.

Setting: All patients included in the study presented to the treating surgeon at a Level I trauma center with isolated calcaneal fractures as an outpatient between 2005 and 2013.

Heritability estimation of osteoarthritis in the pig-tailed macaque (Macaca nemestrina) with a look toward future data collection.

We examine heritability estimation of an ordinal trait for osteoarthritis, using a population of pig-tailed macaques from the Washington National Primate Research Center (WaNPRC). This estimation is non-trivial, as the data consist of ordinal measurements on 16 intervertebral spaces throughout each macaque's spinal cord, with many missing values. We examine the resulting heritability estimates from different model choices, and also perform a simulation study to compare the performance of heritability estimation with these different models under specific known parameter values.

Brief communication: Lumbar lordosis in extinct hominins: implications of the pelvic incidence.

Recently, interest has peaked regarding the posture of extinct hominins. Here, we present a new method of reconstructing lordosis angles of extinct hominin specimens based on pelvic morphology, more specifically the orientation of the sacrum in relation to the acetabulum (pelvic incidence). Two regression models based on the correlation between pelvic incidence and lordosis angle in living hominoids have been developed.

Linear and angular measurements of the foot of modern humans: a test of Morton's foot types.

In his classic research, Morton established two functionally different configurations of the bipedal and non-bipedal primate foot: one optimized for stability, with a stiff longitudinal arch and adducted first metatarsal, and the other for compliance. Modern human feet were seen as conforming to the bipedal norm and variation from it as pathology, even though clinical evidence has been clear that variation from the norm of a stiff longitudinal arch or adducted first metatarsal exists. This study aims to document the variation in linear and angular measurements of the foot, using weight-bearing radiographs of 50 randomly selected people (25 men) from an urban US Level 1 trauma center.