Descending, load carrying, and stepping down relatively large vertical displacements in a single step may simultaneously increase vertical ground reaction force when backpacking. Both high load amplitude and high loading rate have been associated with injury or disease risk. Measurement of countermeasure efficacy may assist participants to control adversity in a popular activity.

This study compared plantar pressure data of vertical ground reaction force (GRF) during backpack loaded descent through two different vertical displacements and measured the effect of steps-down taken with, and without hiking poles. All subjects carried a pack weighing 20% of their body weight.

Neither pole use, nor step-down height, exhibited an effect on time to peak force, although men were significantly faster than women. Step depth significantly affected peak force. Analysis with body mass as a covariant showed pole use significantly reduced peak force. Step depth significantly affected rate of force development.

These results suggest that, for burdened backpackers, taking large negative vertical displacements in stride without modifying their gait may provoke significant peak vertical GRF loads and significantly impulsive rates of lower limb loading. Unsophisticated use of hiking poles may attenuate peak force on deeper step depth without necessarily blunting the rate of force development.