During the first stage of the study, which took place between 2006 and 2009, researchers at the University of Southampton developed a technique to better evaluate the forefeet and diagnose the 'marbles' using diagnostic ultrasound.
A third stage used an MRI scan to visualise the anatomical structures and 'marbles' more clearly in the forefeet (see photo) and resulted in researchers developing the first ever atlas to categorise the swellings originally identified in stage one.
Most of the forefeet
in these devices were made from soft foams or flexible carbon plates that would deform to some extent as the person with amputation progressed on the forefoot, thus compromising the rigid-body assumption of the kinematic model and reflecting a relative increase in the dorsiflexion angle obtained.
Brachiosaurus and Camarasaurus, sauropods that had relatively long front limbs and a balanced weight distribution, floated with their forefeet
deeper than their back feet, Henderson found.
In the case of devices with good suspension and relatively stiff forefeet
, such as the clamshell prostheses in which the forefoot has been made by cutting down a conventional prosthetic foot, a conventional marker set may yield acceptable results.