Vanicek, Natalie, Coleman, Elizabeth, Watson, Judith, Bell, Kerry, Barnett, Cleveland, McDaid, Catriona, Twiste, Martin, Jepson, Fergus, Salawu, Abayomi, Harrison, Dennis, Mitchell, Natasha, "STEPFORWARD study: a randomised controlled feasibility trial of a self-aligning prosthetic ankle-foot for older patients with vascular-related amputations", BMJ Open, 2021