Hatton et al 2012 published a curious study. They took 26 older adults (mean age 79yo) with a self-reported history of > 2 falls in the last 12 months. They had them walk a 10m course in their usual footwear and then with a rough insole that would stimulate the plantar surface of the foot.
The textured insole caused a slower, more cautious gait. Stride length was decreased stance time increased, cycle time increased and double limb support time increased.
The participants reported feeling more secure. This presents an interesting finding. Either the stimulation of the plantar surface does help contribute significantly to balance and pacing- or simply the change in footwear caused the difference. It is entirely possible that this was the first time in many years they had walked without smooth insoles and thus slowed to simply become accustomed to the new stimulation. Unfortunately, the authors don’t say if practice runs were done or some time to acclimatize to the insoles was provided. Knowing how our feet react to new shoes (switching from running shoes to dance shoes for example), one can imagine compounding that problem for 79yos with a history of falling. While clearly an interesting finding, it bears more research before either rough insoles or barefoot shoes become mainstream for the elderly.