Association Between Pain Coping and Symptoms of Anxiety and Depression, and Work Absenteeism in People With Upper Limb Musculoskeletal Disorders: A Systematic Review and Meta-analysis.

OBJECTIVE: To determine the prospective association of pain coping strategies and symptoms of anxiety and depression with work absenteeism in people with upper limb musculoskeletal disorders. DATA SOURCES: A systematic search of PubMed, Web of Science, Embase, Cochrane Library, and Scopus databases was conducted from inception to September 23, 2022. STUDY SELECTION: Prospective observational studies of adults with upper limb musculoskeletal disorders were included. Included studies had to provide data on the association of pain coping strategies (catastrophizing, kinesiophobia, self-efficacy or fear avoidance) or symptoms of anxiety and depression with work absenteeism. DATA EXTRACTION: Study selection, data extraction, and assessment of methodological quality (Newcastle Ottawa Scale) were performed by 2 independent authors. Random-effects models were used for quantitative synthesis. DATA SYNTHESIS: Eighteen studies (n=12,393 participants) were included. Most studies (77.8%) reported at least 1 significant association between 1 or more exposure factors (pain coping strategies or symptoms of anxiety and depression) and work absenteeism. Meta-analyses showed a statistically significant correlation between the exposure factors of catastrophizing (r=0.28, 95% confidence interval [CI]: 0.15 to 0.40; P<.0001) and symptoms of anxiety and depression (r=0.23, 95% CI: 0.10 to 0.34; P=.0003) with work absenteeism. The correlation between self-efficacy and work absenteeism was non-significant (r=0.24, 95% CI: -0.02 to 0.47; P=.0747). CONCLUSIONS: Rehabilitation teams should consider assessing catastrophizing and symptoms of anxiety and depression to identify patients at risk for work absenteeism. Addressing these variables may also be considered in return-to-work programs for individuals with upper limb disorders.

The first Miocene fossils from coastal woodlands in the southern East African Rift.

The Miocene was a key time in the evolution of African ecosystems witnessing the origin of the African apes and the isolation of eastern coastal forests through an expanding arid corridor. Until recently, however, Miocene sites from the southeastern regions of the continent were unknown. Here, we report the first Miocene fossil teeth from the shoulders of the Urema Rift in Gorongosa National Park, Mozambique. We provide the first 1) radiometric ages of the Mazamba Formation, 2) reconstructions of paleovegetation in the region based on pedogenic carbonates and fossil wood, and 3) descriptions of fossil teeth. Gorongosa is unique in the East African Rift in combining marine invertebrates, marine vertebrates, reptiles, terrestrial mammals, and fossil woods in coastal paleoenvironments. The Gorongosa fossil sites offer the first evidence of woodlands and forests on the coastal margins of southeastern Africa during the Miocene, and an exceptional assemblage of fossils including new species.

Modularity of the wrist in extant hominines.

Wrist shape varies greatly across primates and previous studies indicate that the numerous morphological differences among them are related to a complex mixture of phylogeny and function. However, little is known about whether the variation in these various anatomical differences is linked and to what extent the wrist bones vary independently. Here, we used 3D geometric morphometrics on a sample of extant hominines (Homo sapiens, Pan troglodytes, Gorilla gorilla, and Gorilla beringei), to find the model that best describes the covariation patterns among four of the eight carpals (i.e., capitate, lunate, scaphoid, and trapezium). For this purpose, 15 modular hypotheses were tested using the Covariance Ratio. Results indicate that there is a covariation structure common to all hominines, which corresponds to stronger covariation within each carpal as compared to the covariation between carpals. However, the results also indicate that that there is a degree of codependence in the variation of some carpals, which is unique in humans, chimpanzees, and gorillas, respectively. In humans there is evidence of associated shape changes between the lunate and capitate, and between the scaphoid and trapezium. This covariation between lunate and capitate is also apparent in gorillas, while chimpanzees display the greatest disassociation among carpals, showing low covariation values in all pairwise comparisons. Our analyses indicate that carpals have an important level of variational independence which might suggest a high degree of independent evolvability in the wrists of hominines, and that although weak, the structure of associated changes of these four carpals varies across genera. To our knowledge this is the first report on the patterns of modularity between these four wrist bones in the Homininae and future studies might attempt to investigate whether the anatomical shape associations among carpals are functionally related to locomotion and manipulation.

Drosophila Wing Integration and Modularity: A Multi-Level Approach to Understand the History of Morphological Structures.

Static, developmental, and evolutionary variation are different sources of morphological variation which can be quantified using morphometrics tools. In the present study we have carried out a comparative multiple level study of integration (i.e., static, developmental, and evolutionary) to acquire insight about the relationships that exist between different integration levels, as well as to better understand their involvement in the evolutionary processes related to the diversification of Drosophila's wing shape. This approach was applied to analyse wing evolution in 59 species across the whole genus in a large dataset (~10,000 wings were studied). Static integration was analysed using principal component analysis, thus providing an integration measurement for overall wing shape. Developmental integration was studied between wing parts by using a partial least squares method between the anterior and posterior compartments of the wing. Evolutionary integration was analysed using independent contrasts. The present results show that all Drosophila species exhibit strong morphological integration at different levels. The strong integration and overall similarities observed at multiple integration levels suggest a shared mechanism underlying this variation, which could result as consequence of genetic drift acting on the wing shape of Drosophila.

Effects of Cognitive and Mental Health Factors on the Outcomes Following Carpal Tunnel Release: A Systematic Review and Meta-analysis.

OBJECTIVE: To determine the effects of the cognitive and mental health factors on the outcomes after carpal tunnel release (CTR). DATA SOURCES: Embase, PubMed/MEDLINE, Web of Science, Cumulative Index to Nursing and Allied Health, and Cochrane Central Register of Controlled Trials databases from inception to August 14, 2021. STUDY SELECTION: Randomized controlled trials and observational studies of patients with CTR were included. The included studies aimed to determine the effect of the cognitive (catastrophic thinking, kinesiophobia, self-efficacy) or mental health factors (symptoms of anxiety and depression) on the outcomes at least 3 months post CTR. DATA EXTRACTION: Two independent reviewers performed data extraction and assessed the risk of bias. Data were extracted using a standardized protocol and reporting forms. The risk of bias of the included studies was assessed using the Quality in Prognosis Studies risk-of-bias tool. Random-effects models were used for meta-analysis. DATA SYNTHESIS: A total of 15 studies involving 2599 patients were included in this systematic review. The majority of studies indicate a significant association between the cognitive or mental health factors and outcomes after CTR. Quantitative analysis showed a moderate association of symptoms of depression on symptom severity (n=531; r=0.347; 95% CI, 0.205-0.475; P≤.0001), function (n=386; r=0.307; 95% CI, 0.132-0.464; P=.0008), and pain (n=344; r=0.431; 95% CI, 0.286-0.558; P≤.0001). In general, the risk of bias in the included studies was low. CONCLUSIONS: This systematic review and meta-analysis showed that symptoms of depression have a moderate association with symptom severity, function, and pain after CTR. Symptoms of anxiety, catastrophic thinking, and self-efficacy are also important indicators of poor postsurgery outcomes. Physicians, physical therapists, and occupational therapists should consider evaluating these variables in patients undergoing CTR.

Convex hull estimation of mammalian body segment parameters.

Obtaining accurate values for body segment parameters (BSPs) is fundamental in many biomechanical studies, particularly for gait analysis. Convex hulling, where the smallest-possible convex object that surrounds a set of points is calculated, has been suggested as an effective and time-efficient method to estimate these parameters in extinct animals, where soft tissues are rarely preserved. We investigated the effectiveness of convex hull BSP estimation in a range of extant mammals, to inform the potential future usage of this technique with extinct taxa. Computed tomography scans of both the skeleton and skin of every species investigated were virtually segmented. BSPs (the mass, position of the centre of mass and inertial tensors of each segment) were calculated from the resultant soft tissue segments, while the bone segments were used as the basis for convex hull reconstructions. We performed phylogenetic generalized least squares and ordinary least squares regressions to compare the BSPs calculated from soft tissue segments with those estimated using convex hulls, finding consistent predictive relationships for each body segment. The resultant regression equations can, therefore, be used with confidence in future volumetric reconstruction and biomechanical analyses of mammals, in both extinct and extant species where such data may not be available.

Divergence-time estimates for hominins provide insight into encephalization and body mass trends in human evolution.

Quantifying speciation times during human evolution is fundamental as it provides a timescale to test for the correlation between key evolutionary transitions and extrinsic factors such as climatic or environmental change. Here, we applied a total evidence dating approach to a hominin phylogeny to estimate divergence times under different topological hypotheses. The time-scaled phylogenies were subsequently used to perform ancestral state reconstructions of body mass and phylogenetic encephalization quotient (PEQ). Our divergence-time estimates are consistent with other recent studies that analysed extant species. We show that the origin of the genus Homo probably occurred between 4.30 and 2.56 million years ago. The ancestral state reconstructions show a general trend towards a smaller body mass before the emergence of Homo, followed by a trend towards a greater body mass. PEQ estimations display a general trend of gradual but accelerating encephalization evolution. The obtained results provide a rigorous temporal framework for human evolution.

Broad-scale morpho-functional traits of the mandible suggest no hard food adaptation in the hominin lineage.

An on-going debate concerning the dietary adaptations of archaic hominins and early Homo has been fuelled by contradictory inferences obtained using different methodologies. This work presents an extensive comparative sample of 30 extant primate species that was assembled to perform a morpho-functional comparison of these taxa with 12 models corresponding to eight fossil hominin species. Finite Element Analysis and Geometric Morphometrics were employed to analyse chewing biomechanics and mandible morphology to, firstly, establish the variation of this clade, secondly, relate stress and shape variables, and finally, to classify fossil individuals into broad ingesta related hardness categories using a support vector machine algorithm. Our results suggest that some hominins previously assigned as hard food consumers (e.g. the members of the Paranthropus clade) in fact seem to rely more strongly on soft foods, which is consistent with most recent studies using either microwear or stable isotope analyses. By analysing morphometric and stress results in the context of the comparative framework, we conclude that in the hominin clade there were probably no hard-food specialists. Nonetheless, the biomechanical ability to comminute harder items, if required as fallback option, adds to their strategy of increased flexibility.

The biomechanical importance of the scaphoid-centrale fusion during simulated knuckle-walking and its implications for human locomotor evolution.

Inferring the locomotor behaviour of the last common ancestor (LCA) of humans and African apes is still a divisive issue. An African great-ape-like ancestor using knuckle-walking is still the most parsimonious hypothesis for the LCA, despite diverse conflicting lines of evidence. Crucial to this hypothesis is the role of the centrale in the hominoid wrist, since the fusion of this bone with the scaphoid is among the clearest morphological synapomorphies of African apes and hominins. However, the exact functional significance of this fusion remains unclear. We address this question by carrying out finite element simulations of the hominoid wrist during knuckle-walking by virtually generating fused and unfused morphologies in a sample of hominoids. Finite element analysis was applied to test the hypothesis that a fused scaphoid-centrale better withstands the loads derived from knuckle-walking. The results show that fused morphologies display lower stress values, hence supporting a biomechanical explanation for the fusion as a functional adaptation for knuckle-walking. This functional interpretation for the fusion contrasts with the current inferred positional behaviour of the earliest hominins, thus suggesting that this morphology was probably retained from an LCA that exhibited knuckle-walking as part of its locomotor repertoire and that was probably later exapted for other functions.

Morphological consequences of artificial cranial deformation: Modularity and integration.

The cranium is an anatomically complex structure. One source of its complexity is due to its modular organization. Cranial modules are distinct and partially independent units that interact substantially during ontogeny thus generating morphological integration. Artificial Cranial Deformation (ACD) occurs when the human skull is intentionally deformed, through the use of different deforming devices applied to the head while it is developing. Hence, ACD provides an interesting example to assess the degree to which biomechanical perturbations of the developing neurocranium impact on the degree of morphological integration in the skull as a whole. The main objective of this study was to assess how ACD affects the morphological integration of the skull. This was accomplished by comparing a sample of non-deformed crania and two sets of deformed crania (i.e. antero-posterior and oblique). Both developmental and static modularity and integration were assessed through Generalized Procrustes Analysis by considering the symmetric and asymmetric components of variation in adults, using 3D landmark coordinates as raw data. The presence of two developmental modules (i.e. viscero and neurocranium) in the skull was tested. Then, in order to understand how ACD affects morphological integration, the covariation pattern between the neuro and viscerocranium was examined in antero-posterior, oblique and non-deformed cranial categories using Partial Least-Squares. The main objective of this study was to assess how ACD affects the morphological integration of the skull. This was accomplished by comparing a sample of deformed (i.e. antero-posterior and oblique) and non-deformed crania. Hence, differences in integration patterns were compared between groups. The obtained results support the modular organization of the human skull in the two analyzed modules. The integration analyses show that the oblique ACD style differentially affects the static morphological integration of the skull by increasing the covariance between neuro and viscerocranium in a more constrained way than in antero-posterior and non-deformed skulls. In addition, the antero-posterior ACD style seems to affect the developmental integration of the skull by directing the covariation pattern in a more defined manner as compared to the other cranial categories.

Inferring locomotor behaviours in Miocene New World monkeys using finite element analysis, geometric morphometrics and machine-learning classification techniques applied to talar morphology.

The talus is one of the most commonly preserved post-cranial elements in the platyrrhine fossil record. Talar morphology can provide information about postural adaptations because it is the anatomical structure responsible for transmitting body mass forces from the leg to the foot. The aim of this study is to test whether the locomotor behaviour of fossil Miocene platyrrhines could be inferred from their talus morphology. The extant sample was classified into three different locomotor categories and then talar strength was compared using finite-element analysis. Geometric morphometrics were used to quantify talar shape and to assess its association with biomechanical strength. Finally, several machine-learning (ML) algorithms were trained using both the biomechanical and morphometric data from the extant taxa to infer the possible locomotor behaviour of the Miocene fossil sample. The obtained results show that the different locomotor categories are distinguishable using either biomechanical or morphometric data. The ML algorithms categorized most of the fossil sample as arboreal quadrupeds. This study has shown that a combined approach can contribute to the understanding of platyrrhine talar morphology and its relationship with locomotion. This approach is likely to be beneficial for determining the locomotor habits in other fossil taxa.

Analyzing the sclerocarpy adaptations of the Pitheciidae mandible.

Primates are interpreted to be ancestrally adapted to frugivory, although some modern groups show clear adaptations to other diets. Among them, pitheciids stand out for specifically predating seeds. This dietary specialization is known as sclerocarpy and refers to the extraction of seeds from surrounding hard tissues using the anterior dentition followed by the mastication of seeds by the molars. It has been proposed that Callicebus-Pithecia-Chiropotes-Cacajao represent a morphocline of increasingly specialized anatomical traits for sclerocarpic foraging. This study addresses whether there is a sclerocarpic specialization gradient in the mandibular morphology of pitheciids. Finite element analysis (FEA) was used to simulate two biting scenarios and the obtained stress values were compared between different pitheciids. Geometric morphometrics (GM) were used to display the morphological variation of this group. No support was found for the morphocline hypothesis from a biomechanical viewpoint since all pitheciins showed similar stress values and on average Chiropotes rather than Cacajao exhibited the strongest mandible. From a morphological perspective, it was found that there is indeed relative "robusticity" continuum in the pitheciid mandible for some aspects of shape as expected for the morphocline hypothesis, but this gradient could be related to other factors rather than sclerocarpic specialization. The present results are expected to contribute to a better insight regarding the ecomorphological relationship between mandibular morphology and mechanical performance among pitheciids.

The intervals method: a new approach to analyse finite element outputs using multivariate statistics.

BACKGROUND: In this paper, we propose a new method, named the intervals' method, to analyse data from finite element models in a comparative multivariate framework. As a case study, several armadillo mandibles are analysed, showing that the proposed method is useful to distinguish and characterise biomechanical differences related to diet/ecomorphology. METHODS: The intervals' method consists of generating a set of variables, each one defined by an interval of stress values. Each variable is expressed as a percentage of the area of the mandible occupied by those stress values. Afterwards these newly generated variables can be analysed using multivariate methods. RESULTS: Applying this novel method to the biological case study of whether armadillo mandibles differ according to dietary groups, we show that the intervals' method is a powerful tool to characterize biomechanical performance and how this relates to different diets. This allows us to positively discriminate between specialist and generalist species. DISCUSSION: We show that the proposed approach is a useful methodology not affected by the characteristics of the finite element mesh. Additionally, the positive discriminating results obtained when analysing a difficult case study suggest that the proposed method could be a very useful tool for comparative studies in finite element analysis using multivariate statistical approaches.

The evolution of the platyrrhine talus: A comparative analysis of the phenetic affinities of the Miocene platyrrhines with their modern relatives.

Platyrrhines are a diverse group of primates that presently occupy a broad range of tropical-equatorial environments in the Americas. However, most of the fossil platyrrhine species of the early Miocene have been found at middle and high latitudes. Although the fossil record of New World monkeys has improved considerably over the past several years, it is still difficult to trace the origin of major modern clades. One of the most commonly preserved anatomical structures of early platyrrhines is the talus. This work provides an analysis of the phenetic affinities of extant platyrrhine tali and their Miocene counterparts through geometric morphometrics and a series of phylogenetic comparative analyses. Geometric morphometrics was used to quantify talar shape affinities, while locomotor mode percentages (LMPs) were used to test if talar shape is associated with locomotion. Comparative analyses were used to test if there was convergence in talar morphology, as well as different models that could explain the evolution of talar shape and size in platyrrhines. Body mass predictions for the fossil sample were also computed using the available articular surfaces. The results showed that most analyzed fossils exhibit a generalized morphology that is similar to some 'generalist' modern species. It was found that talar shape covaries with LMPs, thus allowing the inference of locomotion from talar morphology. The results further suggest that talar shape diversification can be explained by invoking a model of shifts in adaptive peak to three optima representing a phylogenetic hypothesis in which each platyrrhine family occupied a separate adaptive peak. The analyses indicate that platyrrhine talar centroid size diversification was characterized by an early differentiation related to a multidimensional niche model. Finally, the ancestral platyrrhine condition was reconstructed as a medium-sized, generalized, arboreal, quadruped.

A biomechanical approach to understand the ecomorphological relationship between primate mandibles and diet.

The relationship between primate mandibular form and diet has been previously analysed by applying a wide array of techniques and approaches. Nonetheless, most of these studies compared few species and/or infrequently aimed to elucidate function based on an explicit biomechanical framework. In this study, we generated and analysed 31 Finite Element planar models of different primate jaws under different loading scenarios (incisive, canine, premolar and molar bites) to test the hypothesis that there are significant differences in mandibular biomechanical performance due to food categories and/or food hardness. The obtained stress values show that in primates, hard food eaters have stiffer mandibles when compared to those that rely on softer diets. In addition, we find that folivores species have the weakest jaws, whilst omnivores have the strongest mandibles within the order Primates. These results are highly relevant because they show that there is a strong association between mandibular biomechanical performance, mandibular form, food hardness and diet categories and that these associations can be studied using biomechanical techniques rather than focusing solely on morphology.

Standing on the shoulders of apes: Analyzing the form and function of the hominoid scapula using geometric morphometrics and finite element analysis.

OBJECTIVE: The aim was to analyze the relationship between scapular form and function in hominoids by using geometric morphometrics (GM) and finite element analysis (FEA). METHODS: FEA was used to analyze the biomechanical performance of different hominoid scapulae by simulating static postural scenarios. GM was used to quantify scapular shape differences and the relationship between form and function was analyzed by applying both multivariate-multiple regressions and phylogenetic generalized least-squares regressions (PGLS). RESULTS: Although it has been suggested that primate scapular morphology is mainly a product of function rather than phylogeny, our results showed that shape has a significant phylogenetic signal. There was a significant relationship between scapular shape and its biomechanical performance; hence at least part of the scapular shape variation is due to non-phylogenetic factors, probably related to functional demands. DISCUSSION: This study has shown that a combined approach using GM and FEA was able to cast some light regarding the functional and phylogenetic contributions in hominoid scapular morphology, thus contributing to a better insight of the association between scapular form and function.

Analysing the floral elements of the lost tree of Easter Island: a morphometric comparison between the remaining ex-situ lines of the endemic extinct species Sophora toromiro.

Sophora toromiro (Phil) Skottsb. is a species that has been extinct in its natural habitat Easter Island (Rapa Nui) for over 50 years. However, seed collections carried out before its extinction have allowed its persistence ex-situ in different botanical gardens and private collections around the world. The progenies of these diverse collections have been classified in different lines, most of them exhibiting high similarity as corroborated by molecular markers. In spite of this resemblance observed between the different lines, one of them (Titze) has dissimilar floral elements, thus generating doubts regarding its species classification. The floral elements (wing, standard and keel) belonging to three different S. toromiro lines and two related species were analyzed using geometric morphometrics. This method was applied in order to quantify the floral shape variation of the standard, wing, and keel between the different lines and control species. Geometric morphometrics analyses were able to distinguish the floral elements at both intra (lines) and inter-specific levels. The present results are on line with the cumulative evidence that supports the Titze line as not being a proper member of the S. toromiro species, but probably a hybridization product or even another species of the Edwardsia section. The reintroduction programs of S. toromiro should consider this information when assessing the authenticity and origin of the lines that will be used to repopulate the island.

Modelando la varianza de la forma: morfometría geométrica aplicaciones en biología evolutiva / Modelling shape variance: geometric morphometric applications in evolutionary biology

La comparación de caracteres anatómicos entre organismos ha sido un elemento central de la biología comparada. Históricamente, la clasificación taxonómica y la comprensión de la diversidad biológica se han basado en descripciones morfológicas. En base a una revolución matemática cuantitativa, el estudio de la morfología ha tenido un importante énfasis gracias al desarrollo del análisis de la forma mediante la combinación de métodos estadísticos multivariados y nuevas maneras de visualización. El objetivo de la presente revisión es dar una visión actualizada sobre los avances del estudio de la morfometría geométrica (MG) en biología evolutiva, así como introducir a temáticas en fuerte desarrollo (e.g. estabilidad del desarrollo, integración y modularidad morfológicas, entre otras). Se espera proporcionar una visión amplia del uso de la MG en biología evolutiva, destacando la necesidad de aumentar el esfuerzo de investigación en esta disciplina, junto con llamar la atención acerca de la utilidad de la MG como una herramienta efectiva, precisa, amigable y barata para cuantificar y estudiar la variación morfológica.

The comparison of anatomical traits between organisms has been a central topic in comparative biology. Historically, taxanomic classification and biological diversity understanding have been based on morphological descriptions. Derived from a mathematical quantitative revolution, morphological studies have experienced an important renewal due to the development of shape analysis rooted in statistical multivariate methods and novel visualisation techniques. The aim of the present review is to provide an updated perspective regarding the progress in geometric morphometrics (GMM) applied to evolutionary biology, as well as introducing to cutting-edge subjects (e.g. developmental stability, modularity, morphological integration, among other themes). Thus, it is expected to provide a broad point of view with respect to the appliaction of geometric morphometrics in evolutionary biology, highlighting its usefulness as an effective, accurate, user-friendly and inexpensive method to quantify and study shape variation.

Femoral functional adaptation: a comparison between hunter gatherers and farmers using geometric morphometrics / Adaptación funcional del fémur: una comparación entre cazadores-recolectores y agricultores usando morfometría geométrica

The transition from hunting and gathering to agriculture has been associated with a gracilization in human form, especially in long bones. This has been interpreted as result of an increasingly sedentary lifestyle and reduced workload in the farming populations. However the majority of these evidences have been based on the application of different biomechanical techniques or the qualitative assessment of distinct morphological traits on attachment sites. Hence, this study tried to address whether is possible to distinguish between two different populations (hunter-gatherers and farmers) by quantifying their femoral morphology applying geometric morphometrics. We compared 16 male left femora belonging to two populations of Native Americans from the same geographic region, yet temporally and behaviorally distinct, in order to test if geometric morphometrics were able to differentiate these based solely on the quantitative analysis of shape. The femora were scanned and then small portions of them were segmented in order to generate comparable 3D models. Hundred twelve equidistant landmarks were collected over the whole femoral sections and a Procrustes analysis was performed in order to obtain shape variables. Several PCAs were carried out to elucidate morphometric associations and cross-validated DAs were applied to distinguish between hunter-gatherers and farmers. These procedures were sequentially repeated using different landmarks subsets in order to try to establish the anatomical locations where bone functional adaptation mostly occurs: a) femoral cortex; b) medullary cavity; c) complete femoral section. The results here presented, showed that geometric morphometrics were able to distinguish between the two distinct lifestyles. Moreover, the contrasting results obtained from the analysis of the femoral cortex and the medullary cavity, suggest that long bone remodelling caused by lifestyle differences, mostly occurs on the outer surface of the femoral shaft. This study also showed a relative gracilization of the farmer as compared to the hunter-gatherers.

La transición desde la caza y la recolección a la agricultura ha sido asociada con una gracilización en la forma humana, especialmente en los huesos largos. Esto ha sido interpretado como resultado de un estilo de vida más sedentario y con menor carga de trabajo en las poblaciones agricultoras. Sin embargo, la mayoría de estas evidencias se han basado en técnicas biomecánicas o en la evaluación cualitativa de rasgos morfológicos en los sitios de inserción muscular. Este estudio intentó distinguir entre dos poblaciones diferentes (cazadores-recolectores y agricultores) mediante la cuantificación de su morfología femoral aplicando morfometría geométrica. Dieciséis fémures masculinos pertenecientes a dos poblaciones nativo americanas de la misma región geográfica, aunque temporal y conductualmente diferentes, fueron comparadas con la finalidad de probar si la morfometría geométrica era capaz de distinguirlas. Los fémures fueron escaneados y pequeñas porciones fueron segmentadas para generar modelos 3D. Se colectaron 112 hitos equidistantes sobre toda la superficie femoral y luego se realizó un análisis de Procusto para obtener variables de la forma. Diversos análisis de componentes principales se llevaron a cabo para establecer asociaciones morfométricas, así como también análisis discriminantes con validación cruzada para distinguir entre cazadores-recolectores y agricultores. Estos procedimientos fueron repetidos utilizando diferentes subconjuntos de hitos para establecer donde ocurre mayoritariamente la adaptación funcional del hueso: a) corteza femoral; b) cavidad medular; c) sección femoral completa. Los resultados aquí presentados mostraron que la morfometría geométrica permite distinguir entre ambos modos de vida. Además, los contrastantes resultados obtenidos del análisis de la corteza femoral y cavidad medular, sugieren que el remodelamiento óseo debido a diferentes estilos de vida ocurren mayoritariamente en la superficie de la diáfisis del fémur. Este estudio también mostró una relativa gracilización de la población agricultora al ser comparada con los cazadores-recolectores.