Bilateral variation in limb articular surface dimensions

Abstract

Joint form is frequently used to interpret locomotor and manipulative adaptations and infer physical behavioral patterns in past humans, yet the precise genetic and environmental determinants of joint size are incompletely understood. The aim of this research is to assess the plasticity of limb articular dimension through the use of directional asymmetry as an indicator of mechanical stress during skeletal development. Directional asymmetry is largely attributable to differential mechanical loading during bone growth related to handedness. Because the large majority of individuals are right-handed, it is hypothesized that joint dimensions will be significantly larger in the upper right limb and lower left limb in the crossed symmetry pattern that is typically exhibited in bone lengths. Patterns of bilateral variation were explored by sex and skeletal location. Significant levels of directional asymmetry (P < 0.05) suggest that limb articular surfaces are adapted to the mechanical environment. Biomechanical factors are important in the development and maintenance of articular morphology. Further research, however, is needed to establish the exact relationship between joint size and the mechanical environment.

Limb bone bilateral asymmetry: variability and commonality among modern humans

“…Although FEB has a median of zero, the Wilcoxon signed-ranks test reveals that a significantly higher number of individuals have right-biased %DAs (352 rightbiased versus 239 left-biased). Also, in contrast to the results of a previous study (Plochocki, 2004), femoral head diameters are significantly right biased in %DA, although the average asymmetry is quite small (0.1%). Table 4 shows the percentage of the sample (overall, male, and female) with greater than AE0.5%DA, with results that are consistent with all of these observations.…”

“…Some evidence for much smaller but systematic directional asymmetry favoring the left side has been reported in the human lower limb, especially in the femur (Schultz, 1937;Latimer and Lowrance, 1965;Ruff and Jones, 1981;Plochocki, 2004;see below). This trend has been termed a ''crossed symmetry'' pattern between contralateral limbs (Schaeffer, 1928;Plochocki, 2004).…”

Effects of Exercise Intervention on Knee Morphology in Middle-Aged Women: A Longitudinal Analysis Using Magnetic Resonance Imaging

“…In contrast, Plochocki et al [2006] reported the surface size of the femoral head to be significantly larger in growing mice with voluntary access to physical activity than in controls without such access. Plochocki [2004] also found the subchondral bone surface areas of the right upper limb to be significantly larger than those of the left upper limb in human skeletons from subjects who were supposedly right-handed. In the human second metacarpal, Lazenby et al [2008] recently also observed the mediolateral (but not the dorsopalmar) dimensions of the subchondral bone surfaces to be significantly larger on the right-hand side, but pointed out that the side differences in subarticular bone microarchitecture and diaphyseal bone geometry were quantitatively far more important than those of subchondral bone size.…”

“…Mechanical stimulation has been shown to enhance the biosynthetic activity of the chondrocytes [Sah et al, 1989;Kim et al, 1995;Buschmann et al, 1999;Jin et al, 2001;Waldman et al, 2003], and animal models have suggested that cartilage thickness may adapt to the mechanical loading conditions in healthy joints [Jurvelin et al, 1990;Oettmeier et al, 1992]. To date, however, it is unclear whether adult articular cartilage and joint morphology display phenotypic plasticity and adapt to individual loading histories [Lieberman et al, 2001;Plochocki, 2004;Plochocki et al, 2006;Lazenby et al, 2008].…”

Fluctuating Asymmetry of Human Populations: A Review

“…Even small mechanical stresses caused by handedness may lead to deviation from symmetry in the joint surface. In a study of 80 skeletons from archaeological excavations in Missouri, Plochocki [243] studied joint spaces of the humerus, radius, femur, and tibia. In that study, measures of the joint surfaces in the upper extremities showed higher values on the right side.…”