An Investigation of a Backward Fall from a Helical Staircase

Description
The plaintiff, while descending a helical staircase, turned to look over his shoulder, and toppled over the inner, and steeper, railing. He fell three metres to the floor below, sustaining permanent brain dysfunction. Perform Enhance investigated the anatomical and biomechanical movement patterns responsible for the fall, provided detailed explanations of the fall over the handrail at a given height, and recommended a railing height that would prevent such a fall.

Procedures
Investigation was undertaken at the following levels.

1. Site inspection entailing detailed measurement of the staircase and anthropometric measurement of the plaintiff.
2. Reconstruction of a section of the staircase with height adjustable railing, and an integrated force plate. The integrated force plate enabled precise measurement of forces and friction co-efficients in three planes of motion at the instant the fall commenced.
3. Laboratory simulation and filming of the fall sequence on this dedicated staircase using test subjects of similar weight and stature to the plaintiff.
4. Film digitizing to provide precise information as to the successive recruitment of segments. This data was used to explain why the reflex contraction of specific musculature, and its relationship to the plaintiffs center of mass, precipitated the fall.
5. Bioanimation in which the plaintiff was seen descending the actual staircase to the fourth step. At this instant the plaintiff metamorphosed into a computer generated humanoid figure that was then seen to topple over the railing. Anatomical dissolve demonstrated the recruitment of underlying musculo-skeletal elements with graphic biomechanical detail superimposed.

Conclusions
It was accepted by the court that the staircase was clearly dangerous, presenting geometric complexities that required constant monitoring and adjustment to the gait pattern during descent. It was found that the “shortcut phenomenon”, necessitated an adjustment at each level. It was evident in laboratory testing that subjects could make no postural corrections that would enable them to remain on their feet, nor regain lower limb support once their feet were elevated from the stair surface. Indeed, the reflex contraction of muscles recruited to reverse movement patterns imposed by this staircase, only served to exacerbate them. These contractions succeeded only in elevating the feet and placing the body on the fall side of the railing, rather than returning the trunk to the safe side. The handrail was found to be 18cm lower than that found to be effective for an individual of the plaintiff’s stature. Not only was the barrier offered ineffectual, it took no account of the segmentation dynamics of the lumbar column above, and below, the level of the third lumbar vertebra. The authors therefore recommended a safe railing height of no less than 105cm.