To better understand the association of non-normal foot postures with an increased risk of injury to the lower extremity, Australian researchers evaluated center of pressure (COP) in adults with pes planus, pes cavus, or normal feet. Measures for comparison included COP, lateral-medial force index, and COP excursion index.
After screening, 92 healthy adults (aged 18 to 45) had 1 foot selected for barefoot testing, which included a 5-minute acclimation period and walking along a walkway using a 2-step initiation protocol.
The cavus foot was found to have the slowest average and minimum COP velocity during terminal stance compared with the planus foot. However, on pre-swing, the cavus foot had the fastest maximum COP velocity (top figure).
As for lateral-medial force index, the planus foot showed a lower range during terminal stance compared with the normal foot (bottom figure). These findings help us understand how foot posture impacts COP, especially in the propulsive phases of gait.
Buldt AK, Forghany S, Landorf KB, et al. Centre of pressure characteristics in normal, planus and cavus feet. J Foot Ankle Res.2018 Feb 5;11:3. doi: 10.1186/s13047-018-0245-6. eCollection 2018.