Is forearm curvature in the 'Little Foot' Australopithecus natural or pathological?

The 3.67-million-year-old StW 573 ("Little Foot") Australopithecus from Sterkfontein, South Africa, is the most complete skeleton known in the hominin fossil record.  It's discoverers suggested that the significant curvature of its forearm is the result of a fall from a tree during childhood.  They argued this early Australopithecus suffered acute plastic bowing of the forearm—a deformity common in young children after suffering a traumatic fall onto an outstretched hand, as juvenile bones are more elastic than those of adults.