An adjustable head tool (AHT) is configured for positioning a free motion headform (FMH) having a regulated FMH backoff requirement prior to an impact between the FMH and a target surface having a target point. The AHT has a built-in or a variable backoff angle relative to the position of the target point, and includes a cranial portion and an adjustable facial template. The cranial portion encloses a linkage assembly, and the facial template has one or more facial features. A rotary dial translates the facial template with respect to the cranial portion to maintain the regulated FMH backoff requirement. The cranial portion includes a forehead impact zone having a first set of demarcations, and the rotary dial has a second set of demarcations corresponding to the first set of demarcations. The dial is set so the second set of demarcations matches the first set during positioning of the AHT.