5. Functional implications
The undulating body of the shark balances the lateral motion of
the tail with the lateral motion of the anterior body in the opposite
direction. And the downward and posteriorly directed forces produced
by the tail are balanced by the lift provided by the 8–14◦ body
angle maintained during forward swimming (Wilga and Lauder,
2002). It was previously thought that the fact that sharks produce
downward oriented thrust forces was primarily a factor of their
tail shape. Using two-dimensional hydrodynamic analysis methods