title: Slip-Related Changes in Plantar Pressure Distribution, and Parameters for Early Detection of Slip Events.
abstract: OBJECTIVE
  To investigate differences in plantar pressure distribution between a normal gait and unpredictable slip events to predict the initiation of the slipping process.
  
  
  METHODS
  Eleven male participants were enrolled. Subjects walked onto a wooden tile, and two layers of oily vinyl sheet were placed on the expected spot of the 4th step to induce a slip. An insole pressure-measuring system was used to monitor plantar pressure distribution. This system measured plantar pressure in four regions (the toes, metatarsal head, arch, and heel) for three events: the step during normal gait; the recovered step, when the subject recovered from a slip; and the uncorrected, harmful slipped step. Four variables were analyzed: peak pressure (PP), contact time (CT), the pressure-time integral (PTI), and the instant of peak pressure (IPP).
  
  
  RESULTS
  The plantar pressure pattern in the heel was unique, as compared with other parts of the sole. In the heel, PP, CT, and PTI values were high in slipped and recovered steps compared with normal steps. The IPP differed markedly among the three steps. The IPPs in the heel for the three events were, in descending order (from latest to earliest), slipped, recovered, and normal steps, whereas in the other regions the order was normal, recovered, and slipped steps. Finally, the metatarsal head-to-heel IPP ratios for the normal, recovered, and slipped steps were 6.1±2.9, 3.1±3.0, and 2.2±2.5, respectively.
  
  
  CONCLUSIONS
  A distinctive plantar pressure pattern in the heel might be useful for early detection of a slip event to prevent slip-related injuries.
authors.affiliation: Department of Rehabilitation Medicine, Hanyang University College of Medicine, Seoul, Korea.
authors.forename: Seungyoung
authors.initials: S
authors.lastname: Choi
authors.affiliation: Department of Rehabilitation Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea.
authors.forename: Hyungpil
authors.initials: H
authors.lastname: Cho
authors.affiliation: Department of Rehabilitation Medicine, Hanyang University College of Medicine, Seoul, Korea.
authors.forename: Boram
authors.initials: B
authors.lastname: Kang
authors.affiliation: Department of Rehabilitation Medicine, Hanyang University College of Medicine, Seoul, Korea.
authors.forename: Dong Hun
authors.initials: DH
authors.lastname: Lee
authors.affiliation: Department of Rehabilitation Medicine, Hanyang University College of Medicine, Seoul, Korea.
authors.forename: Mi Jung
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Department of Rehabilitation Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea.
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Jang
keywords: Accident prevention; Accidental falls; Foot; Gait; Pressure