Quantifying sit-to-stand and stand-to-sit transitions in free-living environments using the activPAL thigh-worn activity monitor.

•Sit-to-stand and stand-to-sit transitions can be quantified in free-living condition.•These are different between a healthy and a mobility-impaired population.•Peak velocity and variation in peak velocity could provide novel outcomes.•This information could be used to quantify impairment and monitor age-related changes.