Gait Freeze
People with Parkinsons often suffer from Gait Freeze. This decribed in wikipedia here: https://en.wikipedia.org/wiki/Parkinsonian_gait There is some evidence that appropriate cues like haptic feedback (ie vibration) can help with this.

Suggested reading
Two great sources for information are the Parkinson foundation and the Michael J fox foundation:
and:
Note: Both Support research into cures and aids. We would support any research proposals using our equipment, and we are open to creative funding (hire/ loan/ buy back/ discount) to facilitate this.
Talk of key steps- including plans:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8592896/

Effects of vibration
Several small studies suggest that vibrotactile cueing Can reduce FOG (Freeze of gait). for example: