Thus , various braking systems have been proposed for roller skates and skateboards but none is entirely satisfactory .
A problem common to all types of roller skates , including in - line roller skates and skateboards , is the difficulty in slowing down .
Various braking systems have been proposed for roller skates and skateboards but none is entirely satisfactory .
A problem common to all types of roller skates , including in - line roller skates and skateboards , is the difficulty in slowing down .