The effect of rollover footwear on the rollover function of walking

Background: Rollover footwear is assumed to provide an enhanced surface over which the body can roll more easily. The aim of this study was to investigate the effects of rollover footwear on the rollover function of walking. Methods: Twenty subjects walked in three conditions: (i) a MBT shoe (Masai Barefoot Technology) characterized by a stiff sole rounded in the anterior-posterior direction; (ii) alternative rollover shoe (a prototype of Scholl STARLIT) characterized by a stiff sole rounded in the anterior-posterior direction; (iii) a flat control shoe. Data on the lower limb kinematics and ground reaction force were collected. The rollover function of walking was characterized using the radii of lower limb rollover shapes and duration of terminal double limb support. These data were compared between the three shoe conditions and the relationship between the radii of the curved shoe sole and the radii of the rollover shapes investigated. Results: The radii of the whole and middle part of foot-shoe, ankle-foot and knee-ankle-foot rollover shapes were significantly smaller (i. e. more curved) for MBT (ranging from 12% to 81% smaller) and the rollover shoe (ranging from 2% to 69% smaller) compared with flat shoe (p < 0.05). Double support time decreased significantly for MBT similar to 12% and rollover shoe similar to 7% compared to the flat shoe. For both MBT and rollover shoes, there were positive correlations (r = 0.42-0.60) between the sole radii and radius of foot-shoe rollover shape (p < 0.05). Conclusion: Wearing MBT and the rollover shoe resulted in more curved foot-shoe, ankle-foot and knee-ankle-foot rollover shapes and faster weight transfer. However, the results also indicate that static sole curve is not the only factor influencing the gait rocker function.