Abstract
The life of the pre-European Māori consisted of subsistence strategies ranging from hunter-gatherer to horticultural activities. The femur of both sexes is generally characterised by a flattened proximal shaft rotated inward, and by a short, markedly bowed, robust diaphysis. Femoral rugosity denotes the attachment of relatively great thigh musculature which, in turn, is an indicator of the levels of physical activity associated with the subsistence strategies undertaken. The femoral neck and head is distinguished from contemporary populations and those of comparative subsistence strategies by a larger anterior offset (anteversion) and greater horizontal inclination (Coxa valga). In addition to consistently large femoral anteversion, the femoral head is denoted by a broad, horizontally oval insertion for the ligament of the head (fovea). These external morphological traits are such consistent features within the femur they represent racial attributes of the pre-European Māori population. The femoral morphology of the pre-European Māori has been described by earlier researchers dating back 109 years to 1886. However, there have been limited functional evaluations of the external traits, in particular, how traits are associated with respect to each other. To resolve these limitations and determine a biological basis to femoral morphology a comprehensive analysis of external traits from the femur and pelvis is combined with the biomechanical properties of geometric profiles at six cross-sectional levels of the diaphysis.
From six major regions within New Zealand a total of 107 pooled femora in three catalogued 'series' were measured, of these 52 are male and 55 female, and there are 22 pairs (11 male pairs, 11 female pairs). The external traits measured comprise articular areas, femoral angles, diaphyseal dimensions, and anterior shaft curvature. In addition, pelvic dimensions for matching femora are recorded. Cross-sectional parameters derived from profile areas and second moments of area provide information on compressive strength, and bending rigidities and orientation at each cross-sectional level. Statistical methods employed are univariate F-ratios and Student's t-test, bivariate correlation coefficients, and multivariate principal components, discriminant function, and linear regression.
In this study of the pre-European Māori it is suggested that the normal developmental changes in femoral angles are prevented by extrinsic mechanical influences, such as habitual posture, high levels of physical activity, and greater musculature that alter growth plate morphogenesis. Femoral angles are 'set' on epiphyseal fusion and have limited ability to remodel. The femoral diaphysis in the adult undergoes continual remodelling at the periosteal and endosteal surfaces and provides adaptive plasticity to mechanical loading at the hip and knee. Results indicate differences in absolute and relative values of external and cross-sectional traits that indicate mechanical loading patterns specific to each sex.
Functional interpretation of inter-trait associations suggests that; 1) associations between external traits indicate the functional effect of growth and development on femoral size and shape characteristics. 2) Associations within cross-sectional parameters show relationships between appositional remodelling activity and structural strength. 3) Associations between external and internal traits indicate the importance of mechanical loading patterns established during growth and adulthood to final femoral morphology and subsequently to adaptive remodelling of the adult shaft.