We have a range of branch saws out there. Some of them have straight blades while others tend to come with a curved structure. Unlike the straight models, the curved blades come in designs for the works where you need to reach up into the tree or below the waist. If you prune the tree branch between the range of straight blades (i.e.  Hip to head height region) then you automatically sway or curve the saw to meet the curvature action of the blade.