What Is Pinging, Detonation and Pre-ignition. The terms valve clatter, pinging, pre-ignition and detonation describe the strange rattle or knock coming from an engine. This occurs on acceleration with the engine under a load. Each term describes a slightly different condition, but the result is usually the same with each, engine damage.
The upper arm bone, the humerus, connects the shoulder to the elbow. Humerus fractures are generally divided into three types of injuries based on the location of the fracture. The top of the arm bone is called the proximal humerus, and the bottom of the bone is called the distal humerus.
1 The distal humerus is the center of the elbow hinge. 2  The radial head moves around the distal humerus and also rotates when the wrist is turned up and down.  The olecranon is the part of the ulna that cups the end of the humerus and rotates around the end of the humerus like a hinge.