During a PT visit, the PTA is explaining the patient’s diagn…

During a PT visit, the PTA is explaining the patient’s diagnosis.  The PTA describes the diagnosis as a narrowing of the spinal canal, the nerve root or the foramen, which can be congenital or acquired and can be a result of a disc protrusion, soft tissue structures or joint swelling.  The PTA is describing:

A patient has difficulty maintaining balance on uneven terra…

A patient has difficulty maintaining balance on uneven terrain.  The clinician is taking the patient outside to attempt walking on the grassy areas of the lawn.  What system(s) are MOST likely utilized by the patient to maintain his/her balance when walking on this uneven terrain?