noun
ambulation
am-byuh-LAY-shun/ˌæmbjəˈleɪʃən/
The act or ability of walking from place to place.
The therapist observes the patient's ambulation along the hospital corridor.

Etymology
The Latin verb for walking becomes an action noun: walking viewed as an activity. The selected sense also covers a person's capacity to perform that activity.
In context
most often this happens in the legs people have difficulty walking upstairs getting up out of a chair and can even in some instances cause loss of ambulation
More examples
- The assessment records whether ambulation requires assistance.
- Regular ambulation gives him opportunities to move around the ward.
- A walker supports her ambulation during recovery.