How does wearing slippers affect the movement strategy while crossing over an obstacle?

• Published in: Gait & posture 2021-05, Vol.86, p.17-21
• Main Authors: Ohtsu, Hajime, Togashi, Ryusuke, Hiramuki, Mina, Yoshida, Shinya, Minamisawa, Tadayoshi, Kanzaki, Hideto
• Format: Article
• Language: English
• Subjects: Falling; Margin of stability; Obstacle crossing; Slippers; Toe clearance; Tripping
• ISSN: 0966-6362; 1879-2219
• DOI: 10.1016/j.gaitpost.2021.02.022

•Wearing slippers increases the MoS when the trailing limb crosses an obstacle.•At the same time, wearing slippers dorsiflexes the ankle and increases toe clearance.•These strategies are most likely due to the slippers coming off easily.•These strategies are also probably safety measures to prevent tripping.•Therefore, slippers may not be appropriate footwear in terms of tripping risk. Wearing slippers may increase the risk of tripping while crossing obstacles, regardless of age. This is because slippers are more likely to leave the feet and come into contact with obstacles. However, how wearing slippers affects the movement strategy while crossing over an obstacle has not been clarified. How does wearing slippers affect the movement strategy while crossing over an obstacle? Thirty healthy young adults crossed over an obstacle using a comfortable speed under two conditions: barefoot and wearing slippers. The moment when the leading or trailing limb was crossing the obstacle was defined as obstacle lead (OL) or obstacle trail (OT), respectively. The margin of stability (MoS) as a measure of stability was measured at OL and OT. Toe clearance and lower limb joint angles of the leading limb were measured at OL, and those of the trailing limb were measured at OT. Wearing slippers increased toe clearance and flexed the hip and knee joints, regardless of the crossing event (OL, OT). However, the ankle joint angle did not change between footwear conditions at OL and was significantly dorsiflexed in the slippered condition at OT. In addition, the MoS did not change between footwear conditions at OL and increased significantly in the slippered condition at OT. The increase of the MoS at OT when wearing slippers is probably a conservative strategy to reduce the risk of falling forward when a trip occurs. More attention to avoiding tripping likely caused the ankle to dorsiflex and increased toe clearance. This conservative strategy and increased attention are most likely due to the slippers coming off easily. Since these strategies are probably safety measures to prevent tripping, slippers may not be appropriate footwear in terms of tripping risk.