2007, Piran, Slovenia

Manikins
EVALUATION OF THE ARMY BOOT ANKLE SAGITAL STIFFNESS
Aleš Jurca 2 , Bojan Nemec 1 and Igor B. Mekjavic 1
1 Department of Automation, Biocybernetics and Robotics, Jozef Stefan Institute, Ljubljana;
2 UCS d.o.o., Vrhnika, Slovenia
Contact person: ales.jurca@ucstech.eu
INTRODUCTION
Most army boots are over-the-ankle type of footwear to stabilize and protect the ankle, thus
obstructing the ankle joint movement in the sagittal plane. Gait studies have shown that ankle
joint saggital stiffness may affect energy efficiency. Walking and running in boots with lower
ankle sagital stiffness results in extended ankle joint movement. The ankle joint is therefore
capable of generating significantly more power, which results in increased gait velocity. Due
to the significance of ankle joint saggital stiffness in the efficiency of gait, we designed a test
protocol for evaluating this feature in candidate army boots.
METHOD
The stiffness of the boot ankle was measured on the basis of the resistance of the boot to the
ankle joint rotation (dorsiflexion) in the saggital plane. A foot model (Fig. 1) of the same size
was inserted into the boot to simulate having a human foot in the boot. The foot model has a
two degrees-of-freedom (DOF) ankle joint with no resistance to ankle joint rotation in the
sagital plane. The top of the foot model has a 3 DOF knee joint with no resistance to knee
joint rotation in the sagittal plane, which was fixed to a 3 DOF robot (Cartesian robot
manipulator, Institute Jozef Stefan, Slovenia – Fig. 2).
2 DOF ankle joint
Figure 1. Foot model Figure 2. Cartesian robot manipulator
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