Ecological validity of walking speed assessment after traumatic brain injury - A pilot study

Objective: To assess the ecological validity of walking speed measurement after traumatic brain injury (FBI). Participants: Ten people with TBI who could walk independently and were participating in a rehabilitation program. Design: Walking speed on 3 clinical gait tests (comfortable and fast pace over a 10-m distance and a 6-minute walk test) in 3 "natural" environments (a corridor in a brain injury rehabilitation unit, a car park of a metropolitan shopping center, and inside a metropolitan shopping center). Normative data were collected for 275 able-bodied pedestrians as they walked in the 3 natural environments. Results: For subjects with TBI, agreement between the speeds used in the clinical gait tests and the natural environments was poor (intraclass correlation coefficient [ICC] values ranged from -0.24 to 0.63). The closest speed match was the comfortable paced 10-m walk test and walking in a corridor of a brain injury rehabilitation unit (ICC 0.63). Able-bodied pedestrians walked at significantly faster speeds than did subjects with TBI in all 3 natural environments. Conclusions: Comfortable walking speed appears to have the highest ecological validity of the clinical gait tests investigated. Practice in natural and more complex environments should be incorporated into walking rehabilitation programs for people with TBI.