Can toe-ground footwear margin alter swing-foot ground clearance? 
Falls are an important healthcare concern in the older population and tripping is the primary cause.  Greater swing foot-ground clearance is functional for tripping prevention.  Trips frequently occur due to the lowest part of the shoe contacting the walking surface.  Shoe design effects on swing foot-ground clearance are, therefore, important considerations.  When a shoe is placed on a flat surface, there usually is small vertical margin (VM) between the walking surface and the minimum toe point (MTP).  The current study examined the effects of VM on swing foot-ground clearance at a critical gait cycle event, minimum foot clearance (MFC).  3D coordinates of the swing foot (i.e. MTP and heel) were obtained during the swing phase.  MTP represented the swing foot-ground clearance and various MTPs were modelled based on a range of VMs.  The sagittal orientation of the toe and heel relative to the walking surface was also considered to evaluate effects of VM and swing foot angle on foot-ground clearance.  Greater VM increased the swing foot-ground clearance.  At MFC, for example, 0.09 cm increase was estimated for every 0.1cm VM.  Foot angle throughout the swing phase was typically -30° and 70°.  Increasing swing ankle dorsiflexion can maximise VM, which is effective for tripping prevention.  Further research will be needed to determine the maximum thresholds of VM to be safely incorporated into a shoe.