What is the test for using excessive force in violation of the Eighth Amendment?

The core inquiry in determining whether prison officials used excessive force in violation of the Eighth Amendment is "whether force was applied in a good faith effort to maintain or restore discipline or maliciously and sadistically for the very purpose of causing harm." Hudson v. McMillian, 503 U.S. 1, 6 (1992) (internal citation omitted). To determine if the use of force was wanton and unnecessary, we must examine the necessity of force, the relationship between necessity and amount of force used, the threat reasonably perceived by the responsible officials, and any efforts made to temper the severity of the forceful response. Id.