The influence of different force and pressure measuring transducers on lower extremity kinematics measured during running.

In running analyses where both kinetic and kinematic information is recorded, participants are required to make foot contact with a force and/or pressure measuring transducer. Problems arise if participants modify their gait patterns to ensure contact with the device. There is currently a paucity of research investigating the influence of different underfoot kinetic measuring devices on 3-dimensional kinematics of running. Fifteen participants ran at 4.0 m/s in four different conditions: over a floor embedded force plate, Footscan, Matscan, and with no device. Three-dimensional angular kinematic parameters were collected using an eight camera motion analysis system. Hip, knee, and ankle joint kinematics were contrasted using repeated-measures ANOVAs. Participants also rated their subjective comfort in striking each of the three force measuring devices. Significant differences from the uninhibited condition were observed using the Footscan and Matscan in all three planes of rotation, whereas participants subjectively rated the force plate significantly more comfortable than either the Footscan/Matscan devices. The findings of the current investigation therefore suggest that the disguised floor embedded force plate offers the most natural running condition. It is recommended that analyses using devices such as the Footscan/Matscan mats overlying the laboratory surface during running should be interpreted with caution.