Plantar heel pain and foot loading during normal walking

Plantar heel pain is aggravated by weight-bearing, yet limited evidence exists regarding how people with heel pain load their feet during walking. Knowledge of loading patterns in people with plantar heel pain would enhance the understanding of their foot function and assist in developing intervention strategies. Plantar pressure using the Emed-AT platform (Novel Gmbh, Germany) was collected from 198 people with plantar heel pain and 70 asymptomatic controls during normal walking. Maximum force, force-time integral, peak pressure, pressure-time integral and contact time were measured in four quadrants of the heel, the midfoot and the medial and lateral forefoot. The symptomatic group was sub-divided into equal low-pain and high-pain groups using the Foot Health Status Questionnaire pain score. Following age and body mass comparison, multivariate analyses of covariance were performed to compare the heel pain group to the controls, and the low-pain group to the high-pain group, for each loading variable. The heel pain group displayed lower maximum force beneath the heel, lower peak pressure beneath the postero-lateral heel and lower maximum force beneath the medial forefoot. Force-time integrals were lower beneath the posterior heel regions and higher at the lateral forefoot. People with heel pain also had longer midfoot and forefoot contact time. Higher pain level was associated with lower peak pressure and maximum force beneath regions of the heel. Compared to the controls, people with plantar heel pain demonstrated reduced heel loading and modified forefoot loading consistent with a strategy to offload the painful heel.