The Biomechanical Effects of Backpack Weight on Foot Plantar Pressures Among Long-Distance Hikers: Observational study

Background: Hiking is a prevalent activity with most participants carrying gear in backpacks. Though health experts recommend backpack weight not surpass 10–15% of a hiker's body weight, the effects on foot plantar pressures remain unclear. Methods: Our cross-sectional observational study aimed to assess how varying backpack weights impact foot plantar pressure distribution during walking. We enlisted hikers who had covered at least 20 km in the preceding 24 hours. We recorded participants' sociodemographic and clinical details and utilized the Podoprint® platform to measure the area, force, and pressure on the forefoot, rearfoot, and entire foot. Measurements were taken without a backpack, with the hiker's actual backpack, and with backpacks loaded to 10% and 20% of the hiker's body weight. Results: Results revealed a consistently higher force on the right foot across all conditions. Relative to no backpack, forefoot pressure increased by 5.41% and 8.73% with backpacks weighing 10% and 20% of body weight, respectively (p = 0.005), while increases for the rearfoot were 5.01% and 10.17% (p = 0.015), and for the entire foot, 5.04% and 9.61% (p = 0.002). Conclusions: Surpassing 10% of body weight significantly altered foot pressure in both static and dynamic analyses. Our findings underscore the importance of adhering to recommended backpack weight guidelines to mitigate undue foot pressure during hiking.