DANA POINT, Calif.--The NFL's franchise owners approved four rule changes today related to player safety issues, including one that makes it illegal for a defensive player to hit a defenseless receiver in the head with a hit using the forearm or shoulder.

It already was illegal for a defender to deliver a helmet-to-helmet hit to a defenseless receiver. The new rule extends the protection given to the receiver who's in the act of catching the ball, also prohibiting hits to the receiver's helmet when the defender leads with his shoulder or delivers a forearm.

The rule change was recommended by the NFL's competition committee and was approved by at least three-quarters of the teams. The vote took place here today at the annual league meeting.

The owners also approved a rule giving similar protection to defenders, making it illegal for an offensive player to deliver a blindside block by using the helmet, shoulder or forearm to deliver a blow to a defensive player's head.

Two other safety-related rule changes that were approved apply to kickoffs and kickoff returns.

The kicking team now is prohibited from bunching too many players in the middle of the field, or on a single side of the field. That eliminates dangerous scrambles involving too many players on onside kicks.

The receiving team now is prohibited from using a blocking "wedge" of more than two players on a kickoff return.

Other rule changes proposed by the competition committee haven't been voted upon yet by the owners and remain pending.

One of them would expand the range of plays subject to instant replay review by making a fumble incorrectly ruled an incomplete pass initially subject to replay review.

That rule change would address the officiating gaffe made by referee Ed Hochuli in a game early this past season. Hochuli erroneously called a fumble by Denver Broncos quarterback Jay Cutler an incomplete pass, negating a game-saving fumble recovery by the San Diego Chargers. Because the call was not subject to replay review, the Broncos retained possession of the ball and went on to score a touchdown and game-winning two-point conversion.

Under the proposed rule change, such a call could be reversed by instant replay and the defensive team could be awarded possession of the ball.

A vote on that proposal could come later today or Wednesday.

The competition committee enacted a change on its own to protect quarterbacks against low hits by defenders. As part of an officiating point of emphasis, the committee instructed officials to penalize any defensive player who lunges from the ground, after being knocked down by a blocker, and drives his head or shoulder into the quarterback's lower leg. It remains permissible for a defender to swipe at a quarterback's legs from the ground.

That change does not require a vote by the teams because it is an officiating point of emphasis, not a rule change. That move comes in the offseason after New England Patriots quarterback Tom Brady suffered a season-ending knee injury on a low hit in last year's opener against the Kansas City Chiefs.