Dynamic navicular motion measured using a stretch sensor is different between walking and running, and between over-ground and treadmill conditions.
BACKGROUND
Non-invasive evaluation of in-shoe foot motion has traditionally been difficult. Recently a novel 'stretch-sensor' was proposed as an easy and reliable method to measure dynamic foot (navicular) motion. Further validation of this method is needed to determine how different gait analysis protocols affect dynamic navicular motion.


METHODS
Potential differences in magnitude and peak velocity of navicular motion using the 'stretch sensor' between (i) barefoot and shod conditions; (ii) overground and treadmill gait; and/or (iii) running and walking were evaluated in 26 healthy participants. Comparisons were made using paired t-tests.


RESULTS
Magnitude and velocity of navicular motion was not different between barefoot and shod walking on the treadmill. Compared to walking, velocity of navicular motion during running was 59% and 210% higher over-ground (p < 0.0001) and on a treadmill (p < 0.0001) respectively, and magnitude of navicular motion was 23% higher during over-ground running compared to over-ground walking (p = 0.02). Compared to over-ground, magnitude of navicular motion on a treadmill was 21% and 16% greater during walking (p = 0.0004) and running (p = 0003) respectively. Additionally, maximal velocity of navicular motion during treadmill walking was 48% less than walking over-ground (p < 0.0001).


CONCLUSIONS
The presence of footwear has minimal impact on navicular motion during walking. Differences in navicular motion between walking and running, and treadmill and over-ground gait highlight the importance of task specificity during gait analysis. Task specificity should be considered during design of future research trials and in clinical practice when measuring navicular motion.
Complete Sports Care, Melbourne, Australia ; Lower Extremity Gait Studies Program, Faculty of Health Sciences, La Trobe University, Bundoora, Australia ; Pure Sports Medicine, London, Australia ; Centre for Sports and Exercise Medicine, Queen Mary University of London, London, UK.
Christian J
CJ
Barton
Department of Engineering, Aarhus University, Aarhus, Denmark.
Simon L
SL
Kappel
Department of Engineering, Aarhus University, Aarhus, Denmark.
Peter
P
Ahrendt
Orthopaedic Surgery Research Unit, Aalborg University Hospital, Aalborg, Denmark.
Ole
O
Simonsen
Department of Occupational Therapy and Physiotherapy, Aalborg University Hospital, Aalborg, Denmark ; Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
Michael S
MS
Rathleff
Foot kinematics; In-shoe; Navicular drop; Navicular motion; Stretch-sensor