Author(s): MANDALIDIS, D., KAFETZAKIS, I., Institution: NATIONAL AND KAPODISTRIAN UNIVERSITY OF ATHENS, Country: GREECE, Abstract-ID: 2445

INTRODUCTION:
Hiking is a recreational and physically challenging activity that requires individuals to overcome gravitational resistance during uphill walking and to control excessive impact forces during downhill walking. Considering the impact of increased propulsive forces necessary for uphill walking and the need for effective deceleration strategies during downhill walking, successful and efficient participation in hiking relies on adapting ones speed to the slope of the terrain. This study aimed to investigate the velocity/slope interplay, as determined by Toblers Hiking Function (1), on specific gait kinematic and kinetic parameters.
METHODS:
Thirty-two healthy male and female physically active collegiate students were instructed to walk barefoot at 0% slope (level) with a velocity of 5 km/h, uphill slopes at +10% and +20% with velocities of 3.5 km/h and 2.5 km/h, respectively, and downhill slopes at −10% and −20% with velocities of 5.0 km/h and 3.5 km/h, respectively, on an instrumented treadmill. The walking conditions were conducted in a random order, with each condition lasting 4 minutes, followed by a 2-minute break to prevent fatigue. Gait was analysed in terms of spatial (e.g., step length, step width, foot rotation) and temporal gait parameters (e.g., step time, duration of gait phases) as well as ground reaction forces (GRFs) exerted on the rearfoot, midfoot and forefoot plantar areas.
RESULTS:
Statistical analysis revealed a decrease in step length as the slope/velocity interplay progressively became more challenging during both uphill and downhill walking compared to level walking (p≤0.001). Uphill walking necessitated a progressive increase in outward foot rotation, while downhill walking required an increase in step width. Step and phases of gait cycle durations increased (p≤0.001), while cadence decreased (p≤0.001) during uphill walking conditions. Conversely, step time and the duration of gait phases were shorter, and cadence was higher during downhill walking (p≤0.001). GRFs exerted on the rearfoot, and forefoot were lower when walking on inclined surfaces compared to level walking (p≤0.001), but they remained unchanged on the midfoot. GRFs were also greater on the forefoot and lower on the rearfoot during uphill walking compared to downhill walking.
CONCLUSION:
Walking uphill and downhill at velocities such as those recommended for hiking modifies both spatiotemporal gait characteristics and GRFs. These changes were manifested with shorter and slower steps during uphill walking, ultimately resulting in a slower pace. Conversely, during downhill walking, steps became shorter, wider, and faster, leading to a faster pace. This information may offer insights to various sectors within the hiking industry, as well as to individuals seeking to harness the benefits of outdoor walking by adapting and optimizing specific aspects of it indoors (2).

REFERENCES:
1) Tobler, W. Technical Report, 1993.
2) Niedermeier, M. et al. PLoS One 2017.