Human footprint variation while performing load bearing tasks

Ghosting phenomenon in static and dynamic footprints in India and the United States

Ghosting is the phenomenon that exists when a footprint has a lighter area around the tip of one or more toes or a shadow-like area at the back of the heel. To date, ghosting has been considered primarily a finding of dynamic (walking) footprints, rather than static (standing) footprints. The prevalence of ghosting in static footprints is unknown, and research on its presence in static and dynamic footprints from the same participant is sparse, as are studies on its occurrence in different geographic populations. This study is among the first to evaluate the occurrence of ghosting in the static and dynamic footprints from a particular individual with participants in two geographic populations. A combination of both inkless and ink footprint collection systems were used to obtain a total of 206 bare footprints from 103 adult participants from the United States and India. The data comprised 103 static and 103 dynamic footprints. Ghosting occurred significantly in static footprints, though less frequently than in dynamic footprints. Ghosting in static footprints was seen most often at the first toe, followed by the third and second respectively. This aspect appeared least at the heel. In dynamic footprints, it occurred most at the first toe, followed by the second and fourth toes, and then the third toe and the heel. The prevalence of ghosting in footprints from the United States and India differed in their locations, notably at the first and second toes in the static footprints and at the heel in the dynamic footprints.

Estimation of stature and body weight from static and dynamic footprints - Forensic implications and validity of non-colouring cream method

In the present study, the metric properties of dynamic footprints were analysed using non-colouring method in relation with body parameters and compared with static footprint measurements. The results of the study provide a better understanding of the relationship between static and dynamic footprints, which may be useful for biological profiling that allows more accurate identification. Stature, body weight, five length and two width parameters of dynamic (walking) footprints of young Slovak adults (65 females and 68 males) were analysed. Pearson correlation coefficients were calculated and equations for prediction of stature and body weight by linear regression analysis and multiple regression analysis were developed. Intersex differences were confirmed for all parameters and bilateral for some. Statistically significant differences were found in all measurements (p-value>0.05), except for the width of the standing and walking footprint in the mixed group. A positive correlation was found between the selected footprint diameters with stature (max - r = 0.82) and body weight (max - r = 0.70). Stature could be calculated with an accuracy of up to 4.40 cm and body weight with an accuracy of up to 9.56 kg. The results of the present study show that selected measurements of dynamic footprints correlate with stature and body weight. These results could be used in biological profiling in the medical and forensic fields.

Body mass estimation from footprint size in hominins

Although many studies relating stature to foot length have been carried out, the relationship between foot size and body mass remains poorly understood. Here we investigate this relationship in 193 adult and 50 juvenile habitually unshod/minimally shod individuals from five different populations-Machiguenga, Daasanach, Pumé, Hadzabe, and Samoans-varying greatly in body size and shape. Body mass is highly correlated with foot size, and can be predicted from foot area (maximum length × breadth) in the combined sample with an average error of about 10%. However, comparisons among populations indicate that body shape, as represented by the body mass index (BMI), has a significant effect on foot size proportions, with higher BMI samples exhibiting relatively smaller feet. Thus, we also derive equations for estimating body mass from both foot size and BMI, with BMI in footprint samples taken as an average value for a taxon or population, estimated independently from skeletal remains. Techniques are also developed for estimating body mass in juveniles, who have relatively larger feet than adults, and for converting between foot and footprint size. Sample applications are given for five Pliocene through Holocene hominin footprint samples from Laetoli (Australopithecus afarensis), Ileret (probable Homo erectus), Happisburgh (possible Homo antecessor), Le Rozel (archaic Homo sapiens), and Barcin Höyük (H. sapiens). Body mass estimates for Homo footprint samples appear reasonable when compared to skeletal estimates for related samples. However, estimates for the Laetoli footprint sample using the new formulae appear to be too high when compared to skeletal estimates for A. afarensis. Based on the proportions of A.L. 288-1, this is apparently a result of relatively large feet in this taxon. A different method using a ratio between body mass and foot area in A.L. 288-1 provides estimates more concordant with skeletal estimates and should be used for A. afarensis.

Tracking late Pleistocene Neandertals on the Iberian coast

Here, we report the recent discovery of 87 Neandertal footprints on the Southwest of the Iberian Peninsula (Doñana shoreline, Spain) located on an upper Pleistocene aeolian littoral setting (about 106 ± 19 kyr). Morphometric comparisons, high resolution digital photogrammetric 3D models and detailed sedimentary analysis have been provided to characterized the footprints and the palaeoenvironment. The footprints were impressed in the shoreline of a hypersaline swamped area related to benthic microbial mats, close to the coastline. They have a rounded heel, a longitudinal arch, relatively short toes, and adducted hallux, and represent the oldest upper Pleistocene record of Neandertal footprints in the world. Among these 87 footprints, 31 are longitudinally complete and measure from 14 to 29 cm. The calculated statures range from 104 to 188 cm, with half of the data between 130 and 150 cm. The wide range of sizes of the footprints suggests the existence of a social group integrated by individuals of different age classes but dominated, however, by non-adult individuals. The footprints, which are outside the flooded area are oriented perpendicular to the shoreline. These 87 footprints reinforce the ecological scenario of Neandertal groups established in coastal areas.

Children are not like other loads: a cross-cultural perspective on the influence of burdens and companionship on human walking

A major portion of humans' activity-based energy expenditure is taken up by locomotion, particularly walking. Walking behaviors have energetic outcomes and as such can be important windows into how populations and groups adjust to different environmental and task constraints. While sex differences in the speed of paired walkers have been established by others, the dynamics of how walkers adjust their speed in more varied groups and in groups containing children remains unexplored. Furthermore, little ecological data exists to illustrate the relationships between walking speed and child-carrying. Here, we aim to determine how culture impacts the effects of group composition and infant-carrying on walking speed. Because the determinants of group dynamics and parental investment are partially cultural, we examine walking behavior in the Northwestern United States and in Central Uganda. Using an observational method, we recorded the speed, load carriage, and group composition of pedestrians in a single naturalistic urban environment within each country. Our data suggest that children are treated fundamentally differently than other loads or the presence of walking partners, and that major speed adjustments are child-dependent. Our data furthermore indicate that Ugandans walk more slowly in groups than when alone, while Americans walk more quickly in groups. Clear distinctions between the groups make large generalizations about walking behavior difficult, and highlight the importance of culturally specific contexts.

Estimation of stature and body weight in Slovak adults using static footprints: A preliminary study

The stature and the body weight as part of the biological profile can aid the personal identification. The dimensions of the human foot, as well as the footprint, can be used for the prediction due to the existence of its positive correlation with the stature and body weight. Five diagonal axes and ball breadth of bilateral static footprints of 132 young Slovak adults were obtained. All diameters were larger in a male group than female group. No bilateral differences were found except the first diagonal axis and ball breadth. A positive correlations between the selected footprint diameters with the stature (r = 0.37-0.64) and the body weight (r = 0.29-0.71) were confirmed. The linear and multiple regression prediction equations were developed. A stature prediction equation using the most lateral diameters (the fourth and fifth diagonal axis) exhibited the highest accuracy ranging from 4 to 7.5 cm. Similar results were found for the body weight estimation of the male and mixed group. In the female group, the most medial axis (first and second) exhibited the highest accuracy. The body weight estimation accuracy ranges from 9.09 to 11.09 kg. The real and predicted stature and body weight were compared and found differences were lower than calculated SEEs. Thresholds and prediction trend of under- or overestimation was identified. The results of the present study show that selected measurements of static footprints could be used to predict stature and body weight but should be applied only for Slovaks due to population specificity.