Colin Shaw

Objectives: Morphological variation along the human limb reflects complex structural trade-offs between bone strength and mass. Here we assess how varying levels of plasticity and constraint affect this structure and influence the response to habitual loading along the diaphysis. Materials and Methods: Cross-sectional geometric properties including total area, cortical area, and rigidity were compared from the upper (humerus: 50% of length, radius: 66%, 50%, 4%) and lower (tibia: 50%, 38%, 4%) limbs of male varsity-level athletes and matched controls with distinct habitual loading histories. Results: Geometric properties among cricketers and swimmers were significantly greater at the humeral mid-shaft, mid-proximal radius, and radial midshaft compared to controls. By contrast, no significant differences were found among athletes or controls at the distal radius. The tibial midshafts of hockey players and runners also displayed greater area and rigidity compared to controls. Differences in geometry among the three groups became less pronounced distally, where structure was comparable among athletes and controls at 4% of tibial length. Additionally , coefficients of variation revealed that variation among athletes of the same sport was highest distally in both the upper and lower limb and lowest at midshaft, where structure most closely reflected the activity pattern of each loading group. Discussion: These results support previous research suggesting that distal limb sections are more tightly constrained by safety factors compared to midshafts and proximal sections. Overall, it appears that plasticity and constraint vary not only between limb segments in correspondence to known activity patterns, but also along specific sections of the diaphysis. Am J Phys Anthropol 000:000–000, 2015. V C 2015 Wiley Periodicals, Inc. Long bones are capable of adapting their shape and structure in response to mechanical stimulation through the apposition and resorption of skeletal tissue. In effort to quantify the relationship between habitual loading behavior and morphology, research focused on long bone adaptation has been conducted over the past several decades on bony

The postcranial skeleton of modern Homo sapiens is relatively gracile compared with other hominoids and earlier hominins. This
gracility predisposes contemporary humans to osteoporosis and
increased fracture risk. Explanations for this gracility include reduced levels of physical activity, the dissipation of load through
enlarged joint surfaces, and selection for systemic physiological
characteristics that differentiate modern humans from other primates. This study considered the skeletal remains of four behaviourally diverse recent human populations and a large sample of extant primates to assess variation in trabecular bone structure in the human hip joint. Proximal femur trabecular bone structure was quantified from microCT data for 229 individuals from 31 extant primate taxa and 59 individuals from four distinct archaeological human populations representing sedentary agriculturalists and mobile foragers. Analyses of mass-corrected trabecular bone variables reveal that the forager populations had significantly higher bone volume fraction, thicker trabeculae, and consequently lower relative bone surface area compared with the two agriculturalist groups. There were no significant differences between the agriculturalist and forager populations for trabecular spacing, number, or degree of anisotropy. These results reveal a correspondence between human behavior and bone structure in the proximal femur, indicating that more highly mobile human populations have trabecular bone structure similar to what would be expected for wild nonhuman primates of the same body mass. These results strongly emphasize the importance of physical activity and exercise for bone health and the attenuation of age-related bone loss.

In this chapter we investigate the lower limb structural rigidity (using cross-sectional geometric properties of the diaphyseal midshaft) within a sample of 124 individuals from the Late Upper Paleolithic, Neolithic and Iron Age from Italy, Medieval Germany, and twenty-fi rst Century Britain (long distance runners, fi eld
hockey players, and sedentary controls). Late Upper Paleolithic, Neolithic and Iron Age samples were settled in rugged areas, whereas the other samples inhabited plain areas. The aim of this study is to assess whether fi bular diaphyseal properties
refl ect mobility patterns or terrain properties in past populations. Both fi bular rigidity and relative fi bular rigidity ratio (fi bula/tibia) have been analysed. Results reveal that Late Upper Paleolithic, Neolithic and Iron Age samples show high fibular rigidity and have values of relative fi bular rigidity that are most similar to modern hockey players. The relative fi bular diaphyseal rigidity of hockey players has been previously explained as the consequence of their dynamic and repetitive change of direction. Late Upper Paleolithic and Neolithic individuals are thought to have been highly terrestrially mobile, while Iron Age people were probably fairly
sedentary. However, all of the three groups lived in areas of uneven terrain. We conclude that fi bular rigidity and relative fi bular rigidity are influenced by factors that increase foot eversion/inversion such as frequent directional changes and
uneven terrain. The results of this study suggest that inclusion of the fibula provides a valuable additional perspective that complements traditional predictions of mobility patterns based on the femur or the tibia alone.

It has been hypothesised that limb tapering refl ects an energetic trade-off between bone strength and weight, and selection for tissue economy, resulting in lighter distal limb segments. If adaptive mechanisms constrain the response of osseous tissue to mechanical loading one might expect a higher level of constraint, and therefore less variability, in more distal aspects of the limb. High-resolution CT was used to quantify the distribution and variation in strength (Zp), cortical area (CA) and shape (Imax/Imin) at 5 % intervals along the femoral and tibial diaphysis for a skeletal sample of mid- to late Holocene Native American agriculturalists and  foragers ( M = 21, F = 19). Z p and CA are highest in the proximal femur, decrease at a fairly consistent rate ( Z p increases in the distal femur) and reach their lowest values
at the distal tibia. By contrast, inherent morphological variability (coefficient of variation) for both Z p and CA are relatively constant along both the femur and tibia. The distribution and variation in I max / I min is greater than that of CA or Zp . These fi ndings
support earlier studies that have identified tapering in human limbs, yet, because morphological plasticity appears to be generally consistent across the diaphyses of the femur and tibia, morphological constraint (canalisation) does not seem to be the
overriding mechanism dictating the tapering of limb bone structure.

Human pygmy populations inhabit different regions of the world,
from Africa to Melanesia. In Asia, short-statured populations are often referred to as “negritos.” Their short stature has been interpreted as a consequence of thermoregulatory, nutritional, and/or locomotory adaptations to life in tropical forests. A more recent hypothesis proposes that their stature is the outcome of a life history trade-off in high-mortality environments, where early reproduction is favored and, consequently, early sexual maturation and early growth cessation
have coevolved. Some serological evidence of deficiencies in the growth hormone/insulin-like growth factor axis have been previously associated with pygmies’ short stature. Using genome-wide single-nucleotide polymorphism genotype data, we first tested whether different negrito groups living in the Philippines and Papua New Guinea are closely related and then investigated genomic signals of recent positive selection in African, Asian, and Papuan pygmy populations. We found that negritos in the Philippines and Papua New
Guinea are genetically more similar to their nonpygmy neighbors than to one another and have experienced positive selection at different genes. These results indicate that geographically distant pygmy groups are likely to have evolved their short stature independently. We also found that selection on common height variants is unlikely to explain their short stature and that different genes associated with growth, thyroid function, and sexual development are under selection in different pygmy groups.

This article investigates the relationship between the cortical bone of the radius and the muscle area of the forearm. The aim of this study was to develop a method for muscle area estimation from cortical bone area at 65% of radius length where the muscle area at the forearm is largest. Muscle area and cortical area were measured directly in vivo by peripheral Quantitative Computed Tomography (pQCT). We found significant correlations between muscle area and cortical area (r50.881) in the forearm that are in line with previous studies. We have set up a regression model by testing relevant parameters such as age, sex, forearm length, and stature that were all highly correlated to muscle area. The influence of age and sex on the proportion of muscle area to cortical area is strong and potentially related to the effects of testosterone and estrogen on the muscle-bone-unit. Muscle area estimation from cortical bone is possible with a Percent Standard Error of Estimate (%SEE) ranging from 12.03% to 14.83%, depending on the parameters available
and the age and sex of the individual. Muscle area estimation from cortical bone can provide new information for the study of skeletal and/or fossil human remains.

Previous studies have shown a strong correspondence between long bone bilateral asymmetry and reported handedness. Here, we compare the pattern of asymmetry inmechanical properties of the humerus and secondmetacarpal of Pan troglodytes, recent British industrial and medieval populations, and a broad range of human hunter–gatherers, to test whether technological variation corresponds with lateralization in bone function. The results suggest that P. troglodytes are left-lateralized in the morphology of the humerus and right-lateralized in the second metacarpal, while all human populations are predominantly right-biased in the morphology of these bones. Among human populations, the secondmetacarpals of 63% of hunter–gatherers show right-hand bias, a frequency similar to that found among chimpanzees. In contrast, the medieval and recent British populations show over 80% right-lateralization in
the secondmetacarpal. The proportion of individuals displaying right-directional asymmetry is less than the expected 90% among all human groups. The variation observed suggests that the human pattern of right-biased asymmetry developed in a mosaic manner throughout human history, perhaps in response to technological development.

Most analyses of trabecular microarchitecture in mammals have focused on the functional significance of interspecific variation, but they have not effectively considered the influence of body size or phylogeny on bone architecture. The goals of this study were to determine the relationship between trabecular bone and body size in the humeral and femoral heads of extant primates, and to assess the influence of phylogeny on bone microstructure. Using a sample of
235 individuals from 34 primate species, ranging in body size from 0.06 to 130 kg, the relationships between trabecular bone structure and body size were assessed by using conventional and phylogenetic regression analyses. Bone volume fraction, trabecular thickness and trabecular spacing increase with body size, whereas bone surface-area-to-volume ratio decreases. Shape variables such as trabecular number, connectivity density and degree of anisotropy
scale inversely with size. Most of these variables scale with significant negative allometry, except bone surface-area-to-volume ratio, which scales with slight positive allometry. Phylogenetic regressions indicate a relatively weak phylogenetic signal in some trabecular bone variables. These data demonstrate that, relative to body size, large primates have thinner and more tightly packed trabeculae than small primates. The relatively thin trabeculae
in large primates and other mammals, coupled with constraints on
trabecular thickness related to osteocyte function, suggest that increased skeletal loads in the postcranial joints of large mammals are probably mitigated not only through alterations in trabecular microarchitecture, but also through other mechanisms such as changes in cortical bone distribution, limb posture and gait speed.

"Ontogenetic growth processes in human long bones are key elements, determining the variability of adult bone structure. This study seeks to identify and describe the interaction between ontogenetic growth periods and changes in femoral and tibial diaphyseal shape. Femora and tibiae (n546) ranging developmentally from neonate to skeletally mature were obtained from the Norris Farms No. 36 archeological skeletal series. High-resolution X-ray computed tomography scans were collected. Wholediaphysis
cortical bone drift patterns and relative bone envelope modeling
activity across ages were assessed in five cross-sections per bone (total bone length: 20%, 35%, 50%, 65%, and 80%) by measuring the distance from the section centroid to the endosteal and periosteal margins in eight sectors using ImageJ. Pearson correlations were performed to document and interpret the relationship between the cross-sectional shape (Imax/Imin), total subperiosteal area, cortical area, and medullary cavity area for each slice location and age for both the femur and the tibia. Differences in cross-sectional shape between age groups at each cross-sectional position were assessed using nonparametric Mann-Whitney U tests. The data reveal that the femoral and tibial midshaft shape are relatively conserved throughout growth; yet, conversely, the proximal and distal femoral diaphysis
and proximal tibial diaphysis appear more sensitive to developmentally induced changes in mechanical loading. Two time accelerated change are identified: early childhood and repuberty/adolescence."

"Descriptions of Pleistocene activity patterns often derive from comparisons of long bone diaphyseal robusticity across contemporaneous fossilized hominins. The purpose of this study is to augment existing understanding of Pleistocene hominin mobility patterns by interpreting fossil variation through comparisons with a) living human athletes with known activity patterns, and b) Holocene foragers where descriptions of group-level activity patterns are available. Relative tibial rigidity (midshaft tibial rigidity (J)/midshaft humeral rigidity (J)) was compared amongst Levantine and European Neandertals, Levantine and Upper Palaeolithic Homo sapiens, Holocene foragers and living human athletes and controls. Cross-country runners exhibit significantly (p < 0.05) greater relative tibial rigidity compared with swimmers, and higher values compared with controls. In contrast, swimmers displayed significantly (p < 0.05) lower relative tibial rigidity than both runners and controls. While variation exists among all Holocene H. sapiens, highly terrestrially mobile Later Stone Age (LSA) southern Africans and cross-country runners display the highest relative tibial rigidity, while maritime Andaman Islanders and swimmers display the lowest, with controls falling between. All fossil hominins displayed relative tibial rigidity that exceeded, or was similar to, the highly terrestrially mobile Later Stone Age southern Africans and modern human cross-country runners. The more extreme skeletal structure of most Neandertals and Levantine H. sapiens, as well as the odd Upper Palaeolithic individual, appears to reflect adaptation to intense and/or highly repetitive lower limb (relative to upper limb) loading. This loading may have been associated with bipedal travel, and appears to have been more strenuous than that encountered by even university varsity runners, and Holocene foragers with hunting grounds 2000-3000 square miles in size. Skeletal variation among the athletes and foraging groups is consistent with known or inferred activity profiles, which support the position that the Pleistocene remains reflect adaptation to extremely active and mobile lives."

Cross-sectional geometric (CSG) properties
of human long bone diaphyses are typically calculated
from both periosteal and endosteal contours.
Though quantification of both is desirable, periosteal
contours alone have provided accurate predictions of
CSG properties at the midshaft in previous studies.
The relationship between CSG properties calculated
from external contours and ‘‘true’’ (endosteal and periosteal)
CSG properties, however, has yet to be examined
along the whole diaphysis. Cross-sectional
computed tomography scans were taken from 21 locations
along humeral, femoral, and tibial diaphyses in
20 adults from a late prehistoric central Illinois Valley
cemetery. Mechanical properties calculated from images
with (a) artificially filled medullary cavities (‘‘solid’’)
and (b) true unaltered cross-sections were compared at
each section location using least squares regression.
Results indicate that, in this sample, polar second
moments of area (J), polar section moduli (Zp), and
cross-sectional shape (Imax/Imin) calculated from periosteal
contours correspond strongly with those calculated
from cross-sections that include the medullary cavity.
Correlations are high throughout most of the humeral
diaphysis and throughout large portions of femoral and
tibial diaphyses (R2 5 0.855–0.998, all P < 0.001,
%SEE
8.0, %PE
5.0), the major exception being
the proximal quarter of the tibial diaphysis for J and
Zp. The main source of error was identified as variation
in %CA. Results reveal that CSG properties quantified
from periosteal contours provide comparable results to
(and are likely to detect the same differences among
individuals as) true CSG properties along large portions
of long bone diaphyses.

Understanding the mechanically-mediated response of trabecular bone to locomotion-specific loading patterns would be of great benefit to comparative mammalian evolutionary morphology. Unfortunately, assessments of the correspondence between individual trabecular bone features and inferred behavior patterns have failed to reveal a strong locomotion specific signal. This study assesses the relationship between inferred locomotor activity and a suite of trabecular bone structural features that characterize bone architecture. High-resolution computed tomography images were collected from the humeral and femoral heads of 115 individuals from eight anthropoid primate genera (Alouatta, Homo, Macaca, Pan, Papio, Pongo, Trachypithecus, Symphalangus). Discriminant function analyses reveal that subarticular trabecular bone in the femoral and humeral heads is significantly different among most locomotor groups. The results indicate that when a suite of femoral head trabecular features is considered, trabecular number and connectivity density, together with fabric anisotropy and the relative proportion of rods and plates, differentiate locomotor groups reasonably well. A similar, yet weaker, relationship is also evident in the trabecular architecture of the humeral head. The application of this multivariate approach to analyses of trabecular bone morphology in recent and fossil primates may enhance our ability to reconstruct locomotor behavior in the fossil record.

"Unique compared with recent and prehistoric Homo sapiens, Neandertal humeri are characterised by a pronounced right dominant bilateral strength asymmetry and an anteroposteriorly strengthened diaphyseal shape. Remodeling in response to asymmetric forces imposed during regular underhanded spear thrusting is the most influential explanatory hypothesis.
The core tenet of the ‘‘Spear Thrusting Hypothesis’’, that underhand thrusting requires greater muscle activity on the right side of the body compared to the left, remains untested. It is unclear whether alternative subsistence behaviours, such as hide processing, might better explain this morphology. To test this, electromyography was used to measure muscle activity
at the primary movers of the humerus (pectoralis major (PM), anterior (AD) and posterior deltoid (PD)) during three distinct spear-thrusting tasks and four separate scraping tasks. Contrary to predictions, maximum muscle activity (MAX) and total muscle activity (TOT) were significantly higher (all values, p,.05) at the left (non-dominant) AD, PD and PM compared to the
right side of the body during spear thrusting tasks. Thus, the muscle activity required during underhanded spearing tasks does not lend itself to explaining the pronounced right dominant strength asymmetry found in Neandertal humeri. In contrast, during the performance of all three unimanual scraping tasks, right side MAX and TOT were significantly greater at
the AD (all values, p,.01) and PM (all values, p,.02) compared to the left. The consistency of the results provides evidence that scraping activities, such as hide preparation, may be a key behaviour in determining the unusual pattern of Neandertal arm morphology. Overall, these results yield important insight into the Neandertal behavioural repertoire that aided survival throughout Pleistocene Eurasia."

"Although the correspondence between habitual activity and diaphyseal cortical bone morphology has been demonstrated for the fore- and hind-limb long bones of primates, the relationship between trabecular bone architecture and locomotor behavior is less certain. If sub-articular trabecular and diaphyseal cortical bone morphology reflects locomotor patterns, this correspondence would be a valuable tool with which to interpret morphological variation in the skeletal and fossil record. To assess this relationship, high-resolution computed tomography images from both the humeral and femoral head and midshaft of 112 individuals from eight anthropoid genera (Alouatta, Homo, Macaca, Pan, Papio, Pongo, Trachypithecus, and Symphalangus) were analyzed. Within-bone (subarticular trabeculae vs. mid-diaphysis), between-bone (forelimb vs. hind limb), and among-taxa relative distributions (femoral:humeral) were compared. Three conclusions are evident: (1) Correlations exists between humeral head sub-articular trabecular bone architecture and mid-humerus diaphyseal bone properties; this was not the case in the femur. (2) In contrast to comparisons of inter-limb diaphyseal bone robusticity, among all species femoral head trabecular bone architecture is significantly more substantial (i.e., higher values for mechanically relevant trabecular bone architectural features) than humeral head trabecular bone architecture. (3) Interspecific comparisons of femoral morphology relative to humeral morphology reveal an osteological ‘‘locomotor signal" indicative of differential use of the forelimb and hind limb within mid-diaphysis cortical bone geometry, but not within sub-articular trabecular bone architecture"

"During hominin plantigrade locomotion, the weight-bearing function of the fibula has been considered negligible. Nevertheless, studies conducted on human samples have demonstrated that, even if less than that of the tibia, the load-bearing function of the fibula still represents a considerable portion of the entire load borne by the leg. The present study assesses whether variation in habitual lower limb loading
influences fibular morphology in a predictable manner. To achieve this, both fibular and tibial morphology were compared amongst modern human athletes (field hockey players and cross-country runners) and matched sedentary controls. Peripheral quantitative computed tomography was used to
capture two-dimensional, cross-sectional bone images. Geometric properties were measured at the midshaft for each bone. Results show a trend of increased fibular rigidity from control to runners through to field hockey players. Moreover, relative fibular robusticity (fibula/tibia) is significantly greater in
hockey players compared with runners. These results are likely the consequence of habitual loading patterns performed by these athletes. Specifically, the repeated directional changes associated with field hockey increase the mediolateral loading on the lower leg in a manner that would not necessarily be
expected during cross-country running. The present study validates the use of the fibula in association with the tibia as a mean to provide a more complete picture of leg bone functional adaptations. Therefore, the fibula can be added to the list of bones generally used (tibia and femur) to assess the correspondence between mobility patterns and skeletal morphology for past human populations."

"The presumed link between bilateral asymmetry and lateralized habitual activity in extinct hominins is the basis upon which inferences of ‘hand preference’ often derive. While this presumption is reasonable, in-vivo comparisons of skeletal asymmetries and self-reported handedness are rare, and as a result the accuracy of these inferences is questionable. To assess this relationship in living humans, reported ‘handedness’ was compared against peripheral quantitative computed tomography (pQCT) derived bilateral measurements of humeral, ulnar, and tibial midshaft cortical area (CA) and torsional rigidity (J). Significant bilateral differences were found in the humerus for all groups, and in the ulna for the cricketer and field hockey sub-samples. Additionally, cricketers’ non-dominant tibiae were more robust than their dominant tibiae. An assessment of ‘Dominance Asymmetry’ revealed that measures of CA and J were higher in the dominant humeri in w90% of participants; in the ulna this was true in w75% of cases, and in the tibia CA and J were higher in the dominant limb less than 50% of the time. Comparisons of (self)‘Reported’ hand preference against ‘Predicted’ hand preference (based on the calculation of %
Directional Asymmetry) revealed a low level of error for predictions based on both humeral (w4e5% error) and ulnar (6e11% error) asymmetry. Error was decreased with the exclusion of individuals displaying less than 2.5e5% asymmetry. Contrarily, predictions based on tibial analyses had a much higher level of ‘error’ (w45%). Overall, the results support currently accepted approaches for inferring ‘hand
preference’ from measures of upper limb geometric asymmetry in the hominin skeleton."

"Estimates of muscle and other soft tissue properties derived from hominin skeletal and fossil remains would greatly enhance descriptions of body size and shape, and prior physical and metabolic capabilities. Presently, the utility of this approach is uncertain given the complex nature of the relationship between
muscle and bone. To address various principal issues, peripheral quantitative computed tomography (pQCT) imaging was used to quantify these relationships at the midshaft of the arm, forearm, and lower leg of modern human athletes (runners, field hockey players, swimmers, and cricketers) and control
subjects. Given the presumed behavior patterns of prehistoric hominins, the inclusion of highly active human participants was required. Soft tissue and muscle area was compared with bone area, diaphyseal shape, and torsional rigidity. Relationships were found between muscle area and bone area in the arm,
and muscle area and torsional rigidity in the forearm. However, the high standard error and prediction error that define these relationships indicate that muscle or other soft tissue predictions derived from hominin fossil or skeletal remains would be untenable. In the tibia, the relationship between soft tissue
properties and bone properties were primarily explained by covariation with body size. While the strength of the muscle-bone relationships in the arm and forearm vary among athletes and control subgroups, it appears that habitual upper limb loading performed throughout adolescence neither
strengthens nor weakens this relationship. Future attempts to estimate soft tissue properties from osseous tissue may be improved through the use of medical CT or MRI to image complete limb segments and isolate individual muscles."

"Variation in femoral and tibial diaphyseal
shape is used as an indicator of adaptation to patterns
of terrestrial mobility. Recent experimentation has
implied that lower limb diaphyseal shape may be primarily
influenced by lower limb length, and less so by
mobility patterns. If valid, this would, at most, render
previous interpretations of mobility patterns based on
analyses of diaphyseal shape questionable, and, at least,
require additional standardization that considers the
influence of limb length. Although the consequences
could be profound, this implication has yet to be directly
tested. Additionally, the influence of body breadth on tibial
shape (and to a lesser extent femoral shape) remains
uncertain. Tibial and femoral cross-sectional midshaft
shape measurements, taken from nine Pleistocene and
Holocene skeletal populations, were compared against
lower limb length, limb segment length, and bi-iliac
breadth. Generally, limb length and limb segment length
do not significantly influence femoral or tibial midshaft
shape. After controlling for body mass greater bi-iliac
breadth is associated with a relative mediolateral
strengthening of the femoral midshaft, while the influence
of a wider body shape (BIB/length) is associated
with a relative M-L strengthening of the tibia and femur
of males, and the tibia of females. We conclude that; (1)
mechanical interpretations of lower limb diaphyseal
shape are most parsimonious due to the lack of evidence
for a consistent relationship between segment length
and shape; however, (2) further work is required to
investigate the influence of bi-iliac breadth on both femoral
and tibial midshaft shape."

""Variation in upper limb long bone crosssectional properties may reflect a phenotypically plastic response to habitual loading patterns. Structural differences between limb bones have often been used to infer past behavior from hominin remains; however, few studies have examined direct relationships between behavioral differences and bone structure in humans. To help address this, cross-sectional images (50% length) of the
humeri and ulnae of university varsity-level swimmers, cricketers, and controls were captured using peripheral quantitative computed tomography. High levels of humeral robusticity were found in the dominant arms of cricketers, and bilaterally among swimmers, whereas the most gracile humeri were found in both arms of controls, and the nondominant arms of cricketers. In addition, the dominant humeri of cricketers were more circular than controls. The highest levels of ulnar robusticity were also found in the dominant arm of cricketers, and bilaterally amongst swimmers. Bilateral asymmetry in humeral rigidity among cricketers was greater than swimmers and controls, while asymmetry for ulnar rigidity was greater
in cricketers than controls. The results suggest that more
mechanically loaded upper limb elements––unilaterally
or bilaterally––are strengthened relative to less mechanically
loaded elements, and that differences in mechanical loading may have a more significant effect on proximal compared to distal limb segments. The more circular humerus in the dominant arm in cricketers may be an adaptation to torsional strain associated with throwing activities. The reported correspondence between habitual activity patterns and upper limb diaphyseal properties may inform future behavioral interpretations involving hominin skeletal remains.""

""Mobility patterns affect the loads placed on the lower limbs during locomotion and may influence variation in lower limb diaphyseal robusticity and shape. This relationship commonly forms the basis for inferring mobility patterns from hominin fossil and skeletal remains. This study assesses the correspondence
between athletic histories, varying by loading intensity, repetition and directionality, measured using a recall questionnaire, and peripheral quantitative computed tomography-derived measurements of tibial diaphysis rigidity and shape. Participants included male university varsity cross-country runners (n 5 15), field hockey players (n 5 15), and controls (n 5 20) [mean age: 22.1 (SD 1/2 2.6) years]. Measurements of tibial rigidity (including J, %CA, Imax, Imin, and average cortical thickness) of both runners and field hockey players were greater than controls (P
0.05). Differences in tibial
shape (Imax/Imin, P
0.05) between runners and hockey players reflect pronounced maximum plane (Imax) rigidity in runners, and more symmetrical hypertrophy (Imax, Imin) among hockey players. This corresponds with the generally unidirectional locomotor patterns of runners, and the multidirectional patterns of hockey players. These results support the relationship between mobility and tibial diaphysis morphology as it is generally interpreted in the anthropological literature, with greater levels of mobility associated with increased diaphyseal
robusticity and shape variation. Although exercise intensity may be the primary influence on these properties, the repetitiveness of the activity also deserves consideration. In conclusion, bone morphological patterns can reflect habitual behaviors, with adaptation to locomotor activities likely contributing to variation in tibial rigidity and shape properties in archaeological and fossil samples.""

"This paper introduces a new methodological approach to the quantification of cross-sectional geometric properties based on 3D laser scan data. Avariety of methods have been used to calculate estimates of rigidity in the diaphyses of long bones. CT scan, biplanar radiograph, and periosteal mould techniques have all been applied to collect image data of bone sections to assess biomechanical properties (cross-sectional area and second moments of area). Whilst direct quantification of both endosteal and periosteal contours allows the greatest accuracy, such data correlate highly with a periosteal-only approach that is of greater practical application in many contexts. The advent of non-invasive 3D laser scan technologies presents a method to capture bone surface morphology that can be applied to the study of variation in the cross-sectional properties of human bones. This study tests the correspondence between cross-sectional geometric properties derived from laser scans to those obtained through traditional approaches (periosteal moulding and biplanar radiography). A custom-built program, AsciiSection, is introduced for the automated analysis of biomechanical properties direct from 3D coordinate data. The results indicate that the AsciiSection method is of comparable if not greater accuracy than traditional moulding techniques. The study suggests that there is a strong correlation between middiaphyseal cortical bone distribution and cross-sectional geometry calculated using laser scans. The approach provides a viable alternative to traditional techniques for the estimation of biomechanical properties and also allows the collection of rich data and descriptions of
morphological variation along the diaphysis."