Determination of relationship between foot arch, hindfoot, and hallux motion using Oxford foot model: Comparison between walking and running

Context. Membership analyses of the DANCe and Tycho + DANCe data sets provide the largest and least contaminated sample of Pleiades candidate members to date. Aims. We aim at reassessing the different proposals for the number surface density of the Pleiades in the light of the new and most complete list of candidate members, and inferring the parameters of the most adequate model. Methods. We compute the Bayesian evidence and Bayes Factors for variations of the classical radial models. These include elliptical symmetry, and luminosity segregation. As a by-product of the model comparison, we obtain posterior distributions for each set of model parameters. Results. We find that the model comparison results depend on the spatial extent of the region used for the analysis. For a circle of 11.5 parsecs around the cluster centre (the most homogeneous and complete region), we find no compelling reason to abandon King’s model, although the Generalised King model introduced here has slightly better fitting properties. Furthermore, we find strong evidence against radially symmetric models when compared to the elliptic extensions. Finally, we find that including mass segregation in the form of luminosity segregation in the J band is strongly supported in all our models. Conclusions. We have put the question of the projected spatial distribution of the Pleiades cluster on a solid probabilistic framework, and inferred its properties using the most exhaustive and least contaminated list of Pleiades candidate members available to date. Our results suggest however that this sample may still lack about 20% of the expected number of cluster members. Therefore, this study should be revised when the completeness and homogeneity of the data can be extended beyond the 11.5 parsecs limit. Such a study will allow for more precise determination of the Pleiades spatial distribution, its tidal radius, ellipticity, number of objects and total mass.

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Oxford foot model and weight bearing CT (pedCAT): Comparison of tibia-hindfoot angle and arch height

Foot and Ankle Surgery ◽

10.1016/j.fas.2017.07.1085 ◽

2017 ◽

Vol 23 ◽

pp. 14-15

Author(s):

M.R. Wachowsky ◽

S. D'Souza ◽

T. Wirth

Keyword(s):

Weight Bearing ◽

Arch Height ◽

Foot Model ◽

Oxford Foot Model

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Sagittal Plane Kinematics of Passive Dorsiflexion of the Foot in Adolescent Athletes

Journal of the American Podiatric Medical Association ◽

10.7547/1030394 ◽

2013 ◽

Vol 103 (5) ◽

pp. 394-399 ◽

Cited By ~ 1

Author(s):

Alfred Gatt ◽

Nachiappan Chockalingam ◽

Owen Falzon

Keyword(s):

Repeated Measures ◽

Sagittal Plane ◽

Random Order ◽

Adolescent Athletes ◽

Range Of Movement ◽

Kinematic Data ◽

Repeated Measures Analysis ◽

Foot Posture ◽

Foot Model ◽

Oxford Foot Model

Background: Although assessment of passive maximum foot dorsiflexion angle is performed routinely, there is a paucity of information regarding adolescents’ foot and foot segment motion during this procedure. There are currently no trials investigating the kinematics of the adolescent foot during passive foot dorsiflexion. Methods: A six-camera optoelectronic motion capture system was used to collect kinematic data using the Oxford Foot Model. Eight female amateur gymnasts 11 to 16 years old (mean age, 13.2 years; mean height, 1.5 m) participated in the study. A dorsiflexing force was applied to the forefoot until reaching maximum resistance with the foot placed in the neutral, pronated, and supinated positions in random order. The maximum foot dorsiflexion angle and the range of movement of the forefoot to hindfoot, tibia to forefoot, and tibia to hindfoot angles were computed. Results: Mean ± SD maximum foot dorsiflexion angles were 36.3° ± 7.2° for pronated, 36.9° ± 4.0° for neutral, and 33.0° ± 4.9° for supinated postures. One-way repeated-measures analysis of variance results were nonsignificant among the 3 groups (P = .70), as were the forefoot to tibia angle and hindfoot to tibia angle variations (P = .091 and P = .188, respectively). Forefoot to hindfoot angle increased with the application of force, indicating that in adolescents, the forefoot does not lock at any particular posture as portrayed by the traditional Rootian paradigm. Conclusions: Participants had very flexible foot dorsiflexion, unlike those in another study assessing adolescent athletes. This finding, together with nonsignificant statistical results, implies that foot dorsiflexion measurement may be performed at any foot posture without notably affecting results. (J Am Podiatr Med Assoc 103(5): 394–399, 2013)

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