A blood flow stimulating device comprising: a boot (101) including a sole (111) and an upper; a sock (11) disposed within the boot (101): and a bladder (19) disposed within or on the sock (11), wherein the bladder (19) is configured to undergo repeated inflation and deflation so as to stimulate blood flow in a wearer of the blood flow stimulating device, wherein the sock (11) further includes a toe region (1002), a heel region (1001) and a raised portion (1003) between the toe region (1002) and the heel region that (1001), in use, reduces the distance between the sock (11) and a foot of a wearer of the blood flow stimulating device at the raised portion of the sock.