Average in-home gait speed: investigation of a new metric for mobility and fall risk assessment of elders.

•Average in-home gait speed (AIGS), derived from in-home gait data, is investigated.•AIGS is measured unobtrusively using an environmentally mounted sensor system.•AIGS requires no special procedures or movements be performed by the subject.•AIGS is compared to traditional clinical instruments for assessment among elderly.•AIGS may provide a more accurate and precise picture of mobility and fall risk.