How should the slipper socks fit?
The slipper socks should fit like ankle socks. They are not designed to be long socks.
The non-slip tread should go under the foot and up the back of the heel, as shown in photo.
The reason the tread goes up the back of the heel is because we had feedback from specialist Stroke nursing staff to say that stroke patients tended to use the backs of their heels to try and stand up.