a dive in which the diver bends to touch the ankles before straightening out
<noun.act> [ verb ]
dive into the water bending the body at the waist at a right angle, like a jackknife
<verb.motion>
Jackknife \Jack"knife`\, n. A large, strong clasp knife for the pocket; a pocket knife.
A National Transportation Safety Board study two years ago said that in some cases the lap-only belt made some injuries more severe because they caused the body to violently jackknife upon impact.
Such injuries occurred when the lap belt caused the body to jackknife forward during the accident.
The dives that made Louganis famous _ the jackknife, twister and back dive _ were captured on four silver coins issued by the Marshall Islands, located between the Philippines and Hawaii.