Abstract: A first body for attachment to the undersole portion of a shoe is provided and includes front and rear marginal portions. A second body for underlying the heel portion of a shoe is disposed to the rear of and swingably supported from the rear marginal portion of the first body for swinging relative thereto about a horizontal transverse axis. A spring is operably connected between the first and second bodies and functions to yieldingly upwardly swing the second body relative to the first body and the first body includes a downwardly facing bearing member journalled for rotation about a horizontal axis as well as an upstanding axis. With the first body suitably attached to the forward undersole portion of a shoe, the wearer of the shoe may propel himself with his other shoe and, upon transferring his weight to the shoe from which the first body is supported, roll across a suitable supporting surface.