Same level falls continue to contribute to an alarming number of slip/trip/fall injuries in the mining workforce. The objective of this study was to investigate how walking on different surface types and transverse slopes influences gait parameters that may be associated with a trip event. Gait analysis was performed for ten subjects on two orientations (level and sloped) on smooth, hard surface (control) and irregular (gravel, larger rocks) surfaces. Walking on irregular surfaces significantly increased toe clearance compared to walking on the smooth surface. There was a significant (p < 0.05) decrease in cadence (steps/min), stride length (m), and speed (m/s) from control to gravel to larger rocks. Significant changes in external rotation and increased knee flexion while walking on irregular surfaces were observed. Toe and heel clearance requirements increased on irregular surfaces, which may provide an explanation for trip-induced falls; however, the gait alterations observed in the experienced workers used as subjects would likely improve stability and recovery from a trip.

The objective of this study was to understand gait kinetics while walking on a sand surface (vs. hard surface) with wearing a traditional military ALICE backpack (vs. modularized MOLLE backpack). Twenty healthy male students participated in this study. Each participant completed a total of 72 trials (3 good trials for each testing configuration). These testing conditions were combinations of two surface types (hard, sand), two transverse slopes (flat, 10°), two walking speeds (self-selected, 4 km/h), and three load conditions (no load, MOLLE, ALICE). Walking on sand surface required a greater medial-lateral ground reaction force and a greater maximum vertical impact force. Sand surface gait also resulted in a greater mean knee abduction/adduction moment. Hard surface gait resulted in a greater maximum vertical thrust force, a greater maximum braking force, and a greater maximum propulsive force. In terms of backpack effect comparison, mean hip abduction/adduction moment was greater while wearing the ALICE than the MOLLE. These results suggest that walking on sand with a backpack may increase the potential for injuries from overuse and falls. Hard surface walking on the other hand may increase the risk of foot strain and foot blisters.