Walking Stick, Crutches, Walking Frame (Zimmer), Tri-walker, Rollator
This is the simplest and oldest form of walking aid, they come in various forms, wooden stick with a formed handle, metal folding, metal height adjusting and ones with special handles to help spread your weight and are easy to grip.
The most important thing to get right with a walking stick is the height
Long have gone the old wooden crutches, most now have height adjustment and come with cuffs for extra support and comfort.
Walking Frames (Zimmer frame)
Walking frames are used to support people who are not very stable on their feet and can only walk short distances. They can come with four feet or two feet and two wheels, this aids moving the walking frame forward.
Tri-walkers are a three wheeled walking frame, they help with stability while both walking and standing, they also aid rising from a chair. They are height adjustable and fold up when not in use. A bag can be fixed to the front to carry small items; tri-walkers are good for smooth surfaces.
Rollators are a four wheeled walking frame and usually come with a seat,
They are more stable than a tri-walker, but do not fold up as small. These can be used outside and due to the stability and seat; the more adventurous person with walking difficulties can use them.