Kinematics of center of mass and center of pressure predict friction requirement at shoe–floor interface during walking

Older adults who have previously fallen due to a trip walk differently than those who have fallen due to a slip

“…A recent paper by Yamaguchi et al (2013) suggests that COM and COP kinematics serve as a predictor of friction requirement during the weight acceptance and push-off phases in steady-state movements such as straight walking and transient movements such as turning as well as gait termination and initiation. A greater COM-COP distance during late stance increases the required coefficient of friction and therefore increases the risk of a slip 26 . A more posteriorly aligned COM at this phase of the gait cycle has been linked with falling rather than recovery of a slip perturbation 27 .…”

Required coefficient of friction during turning at self-selected slow, normal, and fast walking speeds

“…This contrasts previously reported RCOF values for straight walking which identify peak RCOF forces at the heel contact phase of gait (Cham and Redfern, 2002; Hanson et al, 1999; Kim et al, 2005; Redfern et al, 2001). Additionally, the peak RCOF values reported for 60° turns (µ= 0.34) (Yamaguchi et al, 2012) and 90° turns (µ= 0.36) (Burnfield et al, 2005) exceed traditional values for straight walking in similar participants ( $\mathrm{normal\mu }\underset{\_}{\approx }0.20$) (Cham and Redfern., 2002; Hanson et al, 1999; Kim et al, 2005; Redfern et al, 2001). Combined with the knowledge that RCOF increases with increased gait speeds (Kim et al, 2005; Powers et al, 2002), the frictional demand during turning, especially at high speeds, may exceed the ACOF in many settings.…”

“…It has recently been shown that peak RCOF during turning occurs at the push-off phase of the gait cycle (Yamaguchi et al, 2012). This contrasts previously reported RCOF values for straight walking which identify peak RCOF forces at the heel contact phase of gait (Cham and Redfern, 2002; Hanson et al, 1999; Kim et al, 2005; Redfern et al, 2001).…”

Efficacy of a rubber outsole with a hybrid surface pattern for preventing slips on icy surfaces

“…The participants knew prior to the trial that they had to land on the icy surface, and this may have led to a change in their gait to decrease slip potential, as reported by Cham and Redfern (2002b). Further investigations under more unpredictable conditions and during other walking conditions (such as turning, gait initiation and gait termination) should increase slip potential (Yamaguchi et al, 2013) and help to verify that the hybrid rubber sole can be utilized as an effective anti-slip device during winter. Asking subjects to perform a distracting cognitive task during the gait trials may also help to reduce adaptation and increase slipping (Woollacott and Shumway-Cook, 2002).…”