Pay attention to how the mechanism works, transcending rollers. Usually this shift forward or toe heels offset ago. The safest and most convenient option is the option offset toe forward, as in the second embodiment, the center of gravity is shifting back, and the child will be filled up in the opposite direction. Also, try several times to push and slide mechanism - after these operations on the soles of shoes, there should be no irregularities or depressions.
Note also the shoes. they are hard and soft. Hard boots are made of a plastic frame with a soft liner-toed inside. This allows the shoe to better protect the leg when falling and hitting. Soft shoes made of fabric - it fits snugly and comfortably keep up to it too easy, which is important for the child. And the hard and soft option should be comfortable for the child. Check the internal seams in the shoes so that they do not rub the foot.
When selecting sliding rollers, consider the possibility of changing the bearings and wheels. For skating better for the child to choose the mean diameter of the wheel. Over time, they can be replaced by a larger wheel.
When buying roller skates for children need to purchase a set of protection - a helmet that protects the head from bumps and falls, elbow pads and knee pads for elbows and knees, as well as protection for the wrists.