Changes in Plantar Pressure Levels Generated Using Military Backpack During Standing Position: An Experimental Study

Abstract

Introduction: The feet are one the main anatomical site affected by injuries arising from load carriage tasks and can negatively affect the soldier mobility reducing the operational capability of an entire military troops. Objective: Identify the changes in the plantar pressure distribution during standing position carrying a military backpack with 15 kg, 20 kg, 25 kg, and no-load (NL) always comparing with control group; and examining if the combat boots contribute to decreasing the plantar pressure. Methods: Twenty-four active-duty male military (26.4±5.6 years; 171.5±3.6 cm; 75.2±6.0 kg) were evaluated in standing posture using an insole baropodometry system wearing a military backpack. The Kruskal-Wallis test was used to check for differences and the Dunnett post hoc test to determine which groups were different from the control (p≤0.05). Results: Data showed a significant decrease in plantar pressure in the forefoot no loaded when we compare barefoot (control = 54.02±19.56 kPa) versus wearing combat boots (35.30±13.00 kPa). With loads there was a significative increase in the plantar pressure only in the rearfoot (control = 74.18±3.80 kPa vs 15 Kg = 89.19±15.49 kPa, 20 Kg = 102.81±15.01 kPa, 25 Kg = 94.20±26.60 kPa). Conclusion: Rearfoot is most affected by the load and boot promoted a significant decrease of plantar pressure in the forefoot in the NL group. Midfoot does not change the plantar pressure. This information can help to minimize the soldier's discomfort.