Discrepancies in plantar pressure distribution between affected and unaffected sides in patients with plantar fasciitis

A fundamental understanding of plantar pressure distribution is important for prescribing an appropriate orthosis and applying nonoperative methods, such as stretching exercises, for the treatment of plantar fasciitis. Despite existing research on plantar pressure distribution, discrepancies between affected and unaffected sides in unilateral plantar fasciitis patients warrant further investigation. This study aimed to evaluate the plantar pressure distribution in patients with unilateral plantar fasciitis by comparing it with that on the contralateral unaffected side.

We retrospectively reviewed records from 20 consecutive patients diagnosed with unilateral plantar fasciitis, using the unaffected side as the control. The emed^® pedobarographic system was used to measure the plantar pressure distribution during gait. The analysis was performed using a 4-mask configuration (toes, forefoot, midfoot, and hindfoot).

Both sides showed no significant differences in radiographic parameters. The affected side showed a significantly higher contact area, maximum force, and force-time integrals in the midfoot. However, the unaffected side demonstrated significantly higher maximum force and force-time integrals in the hindfoot. There was no difference in the distribution of the peak pressure and pressure-time integrals between the two sides in all mask regions. The increased contact area and maximum force in the midfoot on the side with plantar fasciitis may result from heel pain-induced weight transfer from the hindfoot.

The findings of this study provide a basic understanding of plantar pressure distribution in the treatment of plantar fasciitis and highlight the importance of considering inter-side differences when designing treatment interventions or orthotic devices.