How To Legally Stiff Arm Defenders In Football

By Alex Mercer

February 5, 2019

The Stiff arm is one of the most vicious moves a running back can put on a defender in football. A good stiff arm often results in getting a clean palm under the face mask, forcing the player to end up flat on his back.

A legal stiff arm is when the player places his open hand on another player’s helmet, face mask, or shoulder pads to push them away successfully. An illegal stiff arm is when the ball carriers grab or lock their fingers on the opponent’s face mask. Any grabbing or pulling will result in a 15 face mask penalty.

In this article, you’re going to learn how to determine between a legal and illegal stiff arm.

What Is An Illegal Stiff Arm?

To understand the stiff arm, we must understand the rules, hand placement, and stiff arm.

Stiff Arm rules

The Stiff arm, also known as the straight arm, is utilized by running backs in all divisions. It’s a technique that helps fast running backs secure an edge when running away from defenders.

It keeps sloppy arm tackles and players who insist on tackling up high away from your body. Knowing when to use a stiff arm is key, as it will help you prevent penalties/illegal stiff arms.

An illegal stiff arm is when a player tries to stiff-arm a player in the face mask, and 1 of 3 things happen:

  • Hand gets caught in the face mask
  • Grabbing the face mask
  • Punching the player in the head

Having a player’s hand get caught in the face mask can be accidental and may not get called. It’s sporadic for this to happen, but it may cause a player’s face mask to turn, which may signal the referee to throw the flag on the offense.

Grabbing the face mask on a stiff arm is the most common penalty that ball carriers are hit with. Aggressive runners may strike with an open palm and close their fists upon contact with the face mask.

This is also common if the player is weaker than the tackler; the hand may fold naturally into the face mask. Be sure to read the bottom of the article on how to avoid this penalty.

Last is the violent stiff arm, where it literally looks like you’re punching the player in the head. This is also a sporadic case, as most stiff arms are violent and are within the rules.

To ensure no penalty, we want to make sure we’re efficient with our stiff arms and not rattling any bones in our hands.

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What Is A Legal Stiff Arm?

A legal stiff arm is when a player engages a defender’s helmet, face mask, or shoulder pad with their open palm (we’re going to stress the open palm throughout the article) and successfully or unsuccessfully removes the defender away from you.

legal Stiff arm to the face

What do we mean by open palm? Hold up your hand right now and open it all the way, or if you’re showing someone the number 5. This is a key part of stiff-arming, as teaching younger players this concept will always keep your running backs penalty-free.

A key point to note – stiff arms are only legal for the person carrying the football. If any other player on the field does a stiff-arm, it will result in a penalty 100% of the time.

Hand Placement When Using A Stiff Arm

As mentioned, we want to have an open palm when utilizing the stiff arm. The open palm technique will help us for many reasons:

  • Avoid penalties
  • Prevent fingers from getting jammed or broken
  • Provides power from bone structure
  • Bigger strike point

The biggest reasoning is to avoid penalties. The referee could interpret any type of fist or semi-closed hand as illegal hands to the face or a face mask penalty.

The second reason is safety. If the running back is trying to get to the edge or sideline, and there’s a linebacker running full speed, the last thing we want is to have our bent fingers getting caught up in the face mask.

That will almost always result in a jammed or broken finger. As mentioned, theWheneferred to as a “straight arm.” The straight arm, the straight arm hen locked out and engaged with a player’s face mask, acts similar to a piece of wood that is hard to breakthrough.

Proving a larger surface area for the strike point can help us in fighting off defenders. With an open hand, the ball carrier has more room for error when aiming for a face mask than a semi-open or closed hand.

When Not To Use A Stiff Arm

Knowing when to use the stiff arm will increase the success rate when it’s used. Let’s first learn when NOT to use the stiff-arm:

  • Running in between the tackles
  • In the middle of the field

In any zone, power, or dive play that results in running between the tackles, we recommend you shy away from using the stiff arm. There are too many players coming from every direction to worry about one.

Also, if you’re focusing your energy on stiff-arming a player, that means that you’re not worried about the most important thing, the ball. Take it from CJ Anderson in the Super Bowl.

Like the point above, breaking into the open field, in the middle of the field, and trying to stiff-arm is a recipe for disaster. Stiff arming one player will almost certainly lead to another player coming up behind you to strip the football. Ball security is job security!

When To Use The Stiff Arm

Stiff arms should be made when going toward the perimeter or the sidelines. We want to use the sideline as our friend.

For example, if we engage in a stiff arm, and another player knocks the ball out, it will likely go out of bounds. It also gives the ball carrier a few extra yards as the push off of the defender the go out of bounds.

The number one thing that matters the most is securing the football. Being toward the sideline gives the runner the best chance to fight off defenders while protecting the football.


Using the stiff arm is a great tool for both power and speedrunners. Use it mainly toward the sideline and when you’re not running in traffic.

Remember that ball security is everything and turning the football over is not worth a few extra yards.

Related Q & A

What Does Stiff Arm Mean In Football?

A stiff arm means to use a stiff arm to push defenders away literally. This is typically done by the ball carrier to break free from tackles.

Why Is The Stiff Arm Legal?

The stiff arm is legal because the runner is not grabbing or pulling on the opponent’s face mask. An open palm must be used to effectively and legally perform a stiff arm.

About the author

Hey There! My Name is Alex and I run Get Hyped Sports. I created this platform to help people find their love for sports and gaming.

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