This short animation illustrates the set up of a femoral head reduction test. The items shown – a femur, a femoral stem with a femoral head, and an acetabular liner – will be tested in a manner that simulates the instantaneous reduction that occurs to a subluxed femoral head upon heel strike during human gait.
The test will be run with the items positioned anatomically, according to the requirements described in ISO standard 14242-1. The animation describes the sequence of orienting movements that set the bodies into the relative positions existing at the start of the gait cycle. After all required orientations, the entire assembly is rotated into an upside-down orientation (the distal portion of the femur is upward, and the proximal portion of the femur is downward), as it will be viewed from the front of a uniaxial test frame in which the test will be conducted.