What is the test for reasonable use of force by the police?

Under the Fourth Amendment, the police may only use such force as is "objectively reasonable under the circumstances." Graham v. Connor, 490 U.S. 386, 109 S.Ct. 1865 (1989). "The reasonableness of a particular use of force must be judged from the perspective of a reasonable officer on the scene, rather than with the 20/20 vision of hindsight." Id. at 396, 109 S.Ct. at 1872. Moreover, "the calculus of reasonableness must embody allowance for the fact that police officers are often forced to make split-second judgments--in circumstances that are tense, uncertain, and rapidly evolving--about the amount of force that is necessary in a particular situation." Id. at 396-97, 109 S.Ct. at 1872.