Is this gizmo a walker or a rollator?

In my blog post on November 24, 2018 titled A very competent and cheerful medical center I referred to the $70 gizmo shown above as a four-wheel walker. (Its maker Harbor Freight calls it a Sit-or-Stand Behind Rolling Walker). It is useful for getting around after you have been off your feet, or after surgery (like a knee replacement). Hand brakes lock the rear wheels in position, and you can sit and rest on the seat, or use it as a platform for holding objects like a plate of food. But when I looked at the Wikipedia page for Walker (mobility), I found it instead calls that a rollator. That is insider medical jargon for those involved with orthopedics or rehabilitation.

They call this other two-wheel gizmo a walker. Web pages from equipment suppliers or manufacturers describe choosing a walker or rollator. GrahamField has an article discussing The Great Gait Debate: Walker vs. Rollator and the Avacare Medical Blog has another article titled Walker vs. Rollator: How to Choose with a nice infographic.

That Wikipedia page also claims walkers began appearing in the 1950s, based on looking up patents. When I looked instead at PubMed Central, I found a 1990 article by professor Graham Mulley on Walking Frames in the British Medical Journal which reported they originated three decades earlier:  

  
“The first walking frame was designed and make in 1924 by a 12 year old Cincinnati boy, Charles Williams. His aunt had broken her hip and after hospital treatment could move around her hospital room only by standing at the back of her armchair and pushing it in front of her. Charles fashioned a simple wooden walking frame that enabled his aunt to walk with more ease and confidence. The local hospital was impressed with his design and made several metal frames out of gas piping. In the 1950s aluminium frames were produced, and subsequently many modifications and additions were developed. The frame is now one of the most widely used walking aids in the world.”

Professor Mulley also humorously noted:

“Frames are used not only for ambulation. Other uses have been as plant stands, as a television aerial (apparently they give good reception), and as a clothes horse to dry ‘smalls.’ “

A rollator with only one wheel appeared in a Heath Robinson cartoon on the Habits of the night moth.