US Patent 9220941 Limb and limb extremity exercise device

An exercise device is suitable for progressively strengthening the intrinsic muscle groups of a limb extremity and the associated limbs of a user. The device has a base unit and a gripping surface. The gripping surface can be gripped by at least one of the digits of the limb extremity of the user. The exercise device further includes a system for applying resistance. The gripping surface is configured to adapt to fit the shape of the digits of the limb extremity of the user.