School-based screening of plantar pressures during level walking with a backpack among overweight and obese schoolchildren.

Among children, postural modifications due to backpack carriage have direct consequences on how forces are exchanged between body and ground and thus on plantar pressure distribution. However, it is unknown whether such alterations are influenced by the foot structure and functionality typical of obesity. In this study, we tested 65 overweight/obese primary schoolchildren using a pressure platform while walking with and without the backpack. Contact areas, arch index, peak and mean plantar pressures in the forefoot, midfoot and rearfoot were compared with those from an additional 65 age- and gender-matched group of normal-weight children. Backpack carriage modified pressure distribution similarly in both groups, with the exception of mean midfoot pressure, which increased significantly among normal-weight children but not in the overweight/obese group. Notably, the pressure values associated with mass excess and backpack carriage still raise some concerns regarding potential long-term adverse consequences on foot structure and functionality of overweight/obese children. Practitioner summary: Backpack carriage by overweight/obese schoolchildren altered plantar pressures similar to what was observed in their normal-weight peers. Yet, high pressures were found among the overweight/obese children. This raises concerns regarding potential long-term adverse consequences on foot structure and functionality, and supports establishing more specific limits for the carried load.