[Biomechanical fragility of the infant skull]

Following previous experiments on postmortem skull fractures of infants, falls from 82-cm heights onto stone (A), carpet (B) and foam-backed linoleum (C), 35 further falling tests were carried out onto softly cushioned ground. In 10 cases a 2-cm thick foam rubber mat (D) was chosen and in 25 further cases a double-folded (8-cm-thick) camel hair blanket (E). Hence the results of altogether 50 tests could be evaluated. In test groups A-C on a relatively hard surface, skull fractures of the parietale were observed in every case; in test group D this fracture was seen in one case and in test group E in four cases. Measurements along the fracture fissures showed bone thickness of 0.1-0.4 mm. The fracture injuries originated in paper-thin single-layer bone areas without diploe, which can also be considered the preferred regions for skull fractures of older infants following falls from low heights. These results indicate that it is no longer possible to assume that the skull of infants is not damaged after falls from table height.