The Journal of Physical Therapy Science published research on the effects of the modulation of optic flow speed on gait parameters in children with hemiplegic cerebral palsy. Optic flow is the pattern of motion perceived at the retina, which specifies the direction of locomotion and provides vital feedback concerning an individual's regulation of walking velocity.
Gait analysis was completed on 10 children with hemiplegic cerebral palsy under 3 different conditions of optic flow speed: slow, normal, and fast optic flow speed. The children walked across the walkway of a GAITRite system, while watching a virtual reality screen, and walking velocity, cadence, stride length, step length, single support time, and double support time were recorded.
The results indicated the following:
- fast optic flow speed (2 times the normal speed) significantly increased walking velocity, cadence, normalized step length, base of support, and single support cycle of both lower limbs.
- the slow optic flow speed (0.25 times the normal speed) yielded a significantly decreased walking velocity, cadence, normalized step length, base of support, and single support cycle for both lower limbs.
The researchers concluded that: gait training involving modulation of the optic flow speed is feasible and suitable for resolving abnormal gait patterns in children with hemiplegic cerebral palsy.
I am wondering how this could be applied in regular therapy sessions? Any ideas of off the shelf virtual reality to vary visual input speed? All I can come up with is filming some video yourself with varying walking speeds? The WiiFit has a Basic Run but the speed of the objects going by you is based on your own speed. Any suggestions?
Reference: Hyungwon Lim, PhD, PT. Effect of the modulation of optic flow speed on gait parameters in children with hemiplegic cerebral palsy. J Phys Ther Sci. 2014 Jan;26(1):145-8. doi: 10.1589/jpts.26.145. Epub 2014 Feb 6.
Full text article at https://www.jstage.jst.go.jp/article/jpts/26/1/26_jpts-2013-312/_pdf.