An orthopedic device for supporting a lower back of a user includes a mechanical energy store, a pelvic element, an upper body element with a first force transmission element and an upper leg element with a second force transmission element. The upper leg element is arranged on the pelvic element such that it can be swivelled about a first swivel axis, the upper body element is movably arranged relative to the pelvic element, the first force transmission element can be engaged and disengaged with the second force transmission element by moving the upper body element relative to the pelvic element, and the mechanical energy store can be charged and discharged by swivelling the upper leg element relative to the upper body element when the first force transmission element is engaged with the second force transmission element.