The traditional one wheeled barrow can be unstable if the load is not balanced or if pushed on slopes or uneven ground. There is a risk of back injury if a load shifts suddently, or a barrow tips.
Loads have to be lifted onto the barrow.
Two wheeled barrows can provide stablity when moving heavy loads. An example of the use of two wheels is the the Ascender Barrow which can support up to 250kg. This barrow can be pivoted on its handles and the tray lowered flush with the ground. The barrow can then be loaded without the operator having to take the full weight of the load. The bin is designed so that if correctly loaded most of the weight is carried over the axle and wheels.