Biomechanical maturation of foot joints in typically developing boys: Novel insight in mechanics and energetics from a cross-sectional study.

BACKGROUND: A growing body of quantitative evidence has been provided regarding age-related differences in plantar foot loading, multi-segment foot kinematics and muscle activity. Fundamental insight into the joint mechanics and energetics of the maturing foot has yet to be provided. RESEARCH QUESTION/HYPOTHESIS: It was hypothesized that so-called 'biomechancial maturation' joint kinetics would be observed in children underneath the age of eight and that older age-groups would not differ from each other in these parameters. METHODS: Fourty-three typically developing boys were recruited and allocated to three different age groups: 1) an early childhood group, 2) a middle childhood group, and 3) an early and late adolescence group. Multi-segment joint kinematics and kinetics of the Ankle-, Chopart-, Lisfranc- and Hallux joint were collected during barefoot walking. One-way Analysis of Covariance was conducted to examine differences among the outcome measures with group as a fixed factor and walking cadence as covariate. RESULTS: The youngest group differed significantly from the other two age groups with respect to their ankle and chopart joint peak plantarflexion moment (p < 0.05). Ankle and chopart joint peak power generation as well as the lisfranc peak plantarflexion moment was found to be significantly lower in the youngest age group compared to the oldest group (p < 0.05). At the lisfranc joint, the youngest age group demonstrated a significantly higher peak plantarflexion velocity compared to the two older age groups (p < 0.05). SIGNIFICANCE: This study provides novel insight into the biomechanical maturation of the developing foot which may guide clinical interventions in paediatric cohorts.

Skeletal development of hallucal tarsometatarsal joint curvature and angulation in extant apes and modern humans.

The medial cuneiform, namely the curvature and angulation of its distal facet with metatarsal 1, is crucial as a stabilizer in bipedal locomotion and an axis upon which the great toe medially deviates during arboreal locomotion in extant apes. Previous work has shown that facet curvature and angulation in adult dry-bone specimens can distinguish African apes from Homo, and can even distinguish among species of Gorilla. This study provides the first ontogenetic assessment of medial cuneiform curvature and angulation in juvenile (n = 68) and adult specimens (n = 102) using computed tomography in humans and extant ape specimens, including Pongo. Our data find that modern human juveniles initially have a convex and slightly medially oriented osseous surface of the developing medial cuneiform distal facet that flattens and becomes more distally oriented with age. The same pattern (though of a different magnitude) occurs developmentally in the chimpanzee medial cuneiform, but not in Gorilla or Pongo, whose medial cuneiform facet angulation remains unchanged ontogenetically. These data suggest that the medial cuneiform ossifies in a distinguishable pattern between Pongo, Gorilla, Pan, and Homo, which may in part be due to subtle differences in the loading environment at the hallucal tarsometatarsal joint-a finding that has important implications for interpreting fossil medial cuneiforms.

Radiographic measurement of tibial joint angles in sheep.

The aim of this study was to establish normal reference values of anatomic and mechanical joint angles of the tibia in sheep at different age groups. Eighteen clinically healthy Santa Ines sheep were used. The animals were divided into three equal groups according to age: Group I - from six- to eight-months-old, Group II - 2-years-old, Group III - from three- to five-years-old. Anatomic medial proximal and lateral distal tibial angles, mechanical proximal and distal tibial angles, and anatomic caudal proximal and anatomic cranial distal tibial angles were measured from tibiae radiographs (n = 36). In the craniocaudal view, the mean values of the anatomic medial proximal, anatomic lateral distal, mechanical medial proximal, and mechanical lateral distal tibial joint angles were 89.6 masculine, 86.6 masculine, 91.4 masculine, and 85.19 masculine respectively. In mediolateral view, the mean values of the anatomic caudal proximal and anatomic cranial distal tibial angles were 64.55 masculine and 105.69 masculine, respectively. The joint orientation angles of the tibia in sheep showed similar values regardless of animal age for both anatomic and mechanical axes.