Kickback:

Bar nose kickback is one of the more common causes of serious chainsaw injury accidents.

Kickback may occur when the moving chain at the nose or tip of the guide bar touches an object, or when the wood closes in and pinches the saw chain in the cut. Tip or bar nose contact can, in some cases, cause a lightning-fast reverse reaction, kicking the guide bar up and back toward the operator. Pinching the cutting chain along the top of the guide bar may push the guide bar rapidly toward the operator. Either of these reactions may cause you to lose control of the saw, which could result in serious personal injury to yourself or to bystanders.

The top of the tip of the chainsaw guide bar is known as the KICKBACK DANGER ZONE. When contact is made with an object such as a branch or a log, there is a danger of a sudden bar nose kickback reaction.

Modern chainsaws are equipped with a variety of devices intended to reduce the risk of injury from kickback or from other causes. Among these are the chain brake, the front (left) hand guard,