Abstract: Multi-functional wrist and hand expander-trainers for training wrist joints and for the effective execution of various training exercises aimed at a particular development of arm, body and leg muscles. An impact plyometric expander including a handle, a connecting element, and a concave head which is connected to the concave handle by the concave connecting element; the concave connecting element connected to the concave head with the formation of a break, and the concave head having an irregular thickness across its entire surface and a narrowing at the bottom part thereof.

Abstract: The invention relates to the field of sports equipment, and specifically to multi-functional wrist and hand expander-trainers, and can be used as a means for training wrist joints and for the effective execution of various training exercises aimed at a particular development of arm, body and leg muscles. The technical result is the uniqueness of design of the impact plyometric expander, allowing for the application of increased-concentration impact movements, plyometric exercises, energy accumulation, the development of explosive speed, and muscle neurostimulation; in addition, using the present expander makes it possible to gain kinetic energy, forcing individual muscle groups to experience various contractions (eccentric, isometric and concentric contractions) several times each.