Natural walking speed is a great indicator of health and can give physical therapists a clear idea of how safe someone is when walking around their home and community. There has been a large volume of research on walking speed as an indicator of health across diverse groups of people. Due to the strength of the research, walking speed has earned the title ‘the 6th vital sign’ because of how clearly walking pace is associated with a variety of health outcomes. The physical therapist measures walking speed over a 10 meter area and uses a stopwatch to time how long it takes to cover this distance. To get a more comprehensive picture of the range of speeds someone is able to walk, the therapist can time a maximal walking pace allowing a 3-meter acceleration area in addition to the 10 meters for normal walking pace.
Walking speed can give physical therapists an idea of whether someone is at a significant risk of falling, how likely they are to be limited to walking only within their home, and whether they are able to walk quickly enough to safely cross a street. Walking at a pace slower than 0.4 meters per second (m/sec) is correlated with only being able to walk within the home environment. Walking between 0.4 m/sec and 0.8 m/sec indicates someone who is able to walk in the community somewhat but may not be able to go everywhere. For example, they may be able to walk through the grocery store with a cart but be unable to walk safely on uneven sidewalks outside or at the beach. Walking at a pace less than 1 m/sec increases the risk for having a fall and is associated with an increased chance of needing assistance with personal care tasks. Walking at a pace faster than 1.2 m/sec is associated with more independence, increased fitness, and is the speed needed to safely cross a street.
References:
https://pmc.ncbi.nlm.nih.gov/articles/PMC4254896/