Femoral neck‐shaft angle and climate‐induced body proportions

Abstract

Individuals who have relatively greater relative body mass do not necessarily have lower NSA. Population differences in NSA were found to be variable, while differences in RBM remained consistent across the developmental span. Taken together, these results suggest that regardless of body proportions, the degree of declination of NSA is presumed to be similar among individuals with similar gait and ambulatory behaviors. Conversely, populations differ in RBM from birth, and these differences are consistent throughout development. These two measures likely are responsive to diffing stimuli, and any potential relationship is likely complex and multifactorial.

Femoral angle development and locomotor progression in children from 18th and 19th century London

“…Previous research on NSA in adults (Anderson & Trinkaus, 1998) suggests that while a level of individual asymmetry ≥5° is not uncommon, there is little evidence of directional bias where one side has a consistently higher angle than the other. Based on this, a more recent study documenting NSA in infants and juveniles (Child & Cowgill, 2017) used left and right femora interchangeably. In this study, we sought to balance the number of left and right femora in each age group.…”

“…The NSA describes the medial inclination of the proximal femur as measured by the angle between the long axes of the femoral diaphysis and neck (Bräuer, 1988; Child & Cowgill, 2017). Under normal loading conditions, the NSA narrows during ontogeny thereby reducing bending moments of the neck and securing the hip joint (Carter, Orr, Fyhrie, & Schurman, 1987; Radin & Paul, 1974).…”

“…Although several studies note a slight decline in NSA during fetal development (Bulandra, Gielecki, Leciejewska, Karaszewski, & Sieroń, 2003; Jouve et al, 2005; Li, Cui, Henry, & Cooperman, 2019; Souza et al, 2015), the majority of NSA development occurs postnatally in response to the magnitude and direction of shear stresses associated with increased locomotor activity (Carter, Orr, Fyhrie, & Schurman, 1987). From a value ranging between 140° and 160° at birth (Child & Cowgill, 2017; Humphry, 1889; Martin & Saller, 1959), NSA values decline throughout growth eventually reaching adult values during early adolescence (Birkenmaier, Jorysz, Jansson, & Heimkes, 2009; Pujol et al, 2016), which typically range between 122° and 136° (Anderson & Trinkaus, 1998; Igbigbi, 2003; Pick, Stack, & Anson, 1941; Toogood, Skalak, & Cooperman, 2009). As with BCA, variation in NSA tends to reflect differences in physical activity (Anderson & Trinkaus, 1998; Houston & Zaleski, 1967) and anatomical differences between sexes (Igbigbi, 2003; Pujol et al, 2016).…”

“…Despite a strong consensus concerning the relationship between the onset of walking and femoral angle development (Child & Cowgill, 2017; Tardieu, 2010; Tardieu & Damsin, 1997), the impact of locomotor behaviors prior to the onset of walking remains unclear. Furthermore, few studies have examined both BCA and NSA during skeletal growth and those that have (Pujol, Rissech, Ventura, Badosa, & Turbón, 2014; Pujol et al, 2016) have focused on older children aged 9–14 years.…”

Diet and adult age‐at‐death among mobile foragers: A synthesis of bioarcheological methods

“…Its methods can be used to explore how populations absorb the stress of environmental change, insofar as the skeleton provides evidence of life course challenges. An extensive literature documents the physical responses of whole bones to habitual behaviors and environmental stressors (Child & Cowgill, ; Martin, Harrod, & Pérez, ; Schrader, ). These gross morphological patterns are the result of cellular (i.e., osteoclastic and osteoblastic) responses, so bone microstructure may show patterns that are as distinctive as the gross morphological patterns.…”