An Investigation of a Cervical Spine Injury as a Result of a Diving Accident

Description
The plaintiff was holidaying on the banks of a river and during early morning exercise decided to take a swim. He ran down the riverbank, along a jetty and executed a running dive over a chain barrier, an extension of the jetty and a pontoon. The high velocity entry was accompanied by an explosive movement of the arms to the sides, leaving the head exposed. The plaintiff had not tested the depth of the water before diving and was unaware that he was diving into shallow water. Given this factor, and the high velocity of the entry, the head impacted with the riverbed sustaining severe injury, and resulting in quadriplegia.

Procedures
Investigation was undertaken at the following levels.

1. Filming of two different diving techniques, head first and hand first, to determine the movement patterns, kinematic detail and anatomical implications associated with each dive. One dive involved a sustained extended position of the arms with hands clasped together in front of the head throughout the flight, entry and submersion. In the second dive the arms were explosively brought to the sides during the same phases.
2. Synchronized filming, above and below water, using test subjects of similar height and weight to the plaintiff.
3. Film digitizing to determine precise segment recruitment, displacements, velocities and accelerations during flight, entry and submersion.
4. Electromyography to determine, for both dives, the varying recruitment of muscles and their contractile intensity .
5. Bioanimation to demonstrate the sequence of events leading to the injury. Comparative movement patterns associated with each dive were highlighted with biomechanical detail graphically superimposed to highlight such detail as entry angles and velocities.

Conclusions
The longer parabolic and higher velocity pathway resulted in an extremely high entry velocity and high impact force with the riverbed. Electromyography also confirmed that the atypical arm action during flight and entry brought about a body attitude and movement patterns that exposed the head to trauma. The need to clear the obstacles contributed to high entry velocities of around 5m/sec and a steep angle of entry between 45 –59 degrees. These variables were considered critical in the depth of a dive. A rigid body position on entry, with the legs flipping over the head, contributed to the vertical descent through the water. It was demonstrated that at impact the divers velocity was 3.1m/sec, exposing the head to high impact velocities.