The Fundamentals of...
 
Notifications
Clear all

The Fundamentals of Football: Inertia, Balance, and Leverage


Coach Kyle
(@coach-kyle)
Platinum
Joined: 11 years ago
Posts: 3826
Topic starter  

I often hear people say "leverage", but I have never heard it explained. So I decided to do a little research, and I have concluded that these 3 things are the underlying fundamental physics concepts at play. Everything about the techniques you create or use should be done to maximize these three concepts. 

Inertia is the momentum of an object or an object's tendency to stay at rest. Players who are slow off the ball fail to be effective blockers, tacklers, or running backs. This is because of the force calculation (Mass * Acceleration = Force). A player who is half the size can move faster and win. This one isn't a secret, but we all know certain things can improve our own acceleration or slow down the acceleration of opponents. Confusion is a great means to slow down the other team. Moving players around with motion. We can also deter a player with cut blocks and bear crawls. These things slow down a big man and pay dividends later on. If your offense/defense don't have these things then you're putting yourself at a disadvantage.

Balance is the ability for a player to stay on their feet in a good athletic position so that they can make play. Balance is not always necessarily important because some times it's more important to throw the opponents off balance. Like mentioned earlier, a cut block can achieve this. A flying tackle sometimes knocks someone over. However, it is best to maintain balance at all times. When a player is on their feet they can recover and continue to contribute to the play. Think about a ball carrier. When they lose balance, they fall over and that play is over. Think about a tackler. When they lose balance they fall to the ground, and if they did not tackle the running back the play continues. Think about a blocker. When they lose balance they miss their block. 

How is balance maintained? Two feet on the ground with the center of mass forming a triangle above it. Imagine the 3 points of the triangle being the two feet and the center of mass.  Each step creates a new triangle between the 3 points. Picture a man bracing himself with a shield. His backfoot is likely pivoted 90 degrees so that it braces the oncoming assault. By putting his foot at this angle he has created the strongest base for bracing against forward force. This is why you'll typically see lineman with their feet taking this position when they're losing a sumo drill. 

So if the best base to withstand frontal force is with one foot back, why don't we block that way? Many football coaches know that the proper lineman drive block technique is a farmer's walk. A farmer's walk is when you take short choppy steps and avoid bracing like you would with a shield. By taking short choppy steps you maintain balance on two feet for more of the time. Picture yourself holding the shield and bracing. You have a force pushing you back. In order to take ground from your opponent, you must put one foot in front of the other. To do this you must take a very large step forward, which means putting one foot on the ground for a long time. This inverts your triangle. Now your triangle has a single point on the ground and two points resting on your opponent. This is where you are most likely to lose balance. 

You can feel this when you brace against a wall. Try out both stances while leaning on a wall and notice the different forces at play. With one foot back you can put more force into your initial push. However, you will find yourself considerably more off balance if you try to drive forward. When you take your step the wall does not give. This has the effect of standing you upright, which would be bad for your leverage. The wall also allows you to put more weight against it than a player would. The other player is likely going to be moving, and so you cannot put as much force against them without losing balance. Now do it the other way and square up your stance. You will notice that you cannot put quite as much force into the wall as you could before, but what you lose in force you make up for in balance.

We as football coaches should not only teach proper techniques that have good balance. We should also teach how to defeat players with bad techniques. This means we must teach them to recognize certain bad techniques. One bad technique is what was just mentioned. The bracing stance is unbalanced, and it would be very vulnerable to a twisting action, especially one that twists the opponent onto their heels. Creating combinations of pushes and pulls and twists creates a lot of trouble for someone who is unbalanced. Your lineman should be able to recognize opponents who are too low to the ground to have proper balance, and they should understand that pushing them down would be a lot more effective than picking them up. Defensive lineman who recognize that a offensive lineman is leaning too much should use the pull through technique on the next play. 

Leverage is often talked about in football, but I don't feel like it is frequently explained well. A lever is anything that has a lever arm and is rotating around a fixed axis point. In football the fixed access point is the ground, and your body is the lever arm. Additionally, there is a second lever involving your shoulders. There are plenty of levers on the human body. Your arms and legs are all levers. Everywhere that you bend are levers too, but there are really only a few levers that matter in football. The most talked about concept involving levers is "the low man wins". That statement is actually potentially misleading.

To understand levers you can do several demonstrations. First take your arm and hold it out perpendicular to your body. Now pull on your wrist. You'll notice that it pulls fairly easily. Next pull on your elbow, and you'll notice that you have a more difficult time dragging your arm down. This is all about levers. Your torque is maximized when you push on the right area of the lever arm. Torque just means rotating force. You want that point to be as far away from the pivot point as possible. Imagine yourself standing straight up with both feet together. If I were to push on your forehead, I would easily be able to knock you over. I could probably do it with one finger. This is because I am applying force at the proper place. Furthermore, the angle at which you push also matters. Force is greatest when it is 90 degrees from the pivot point. So if superman could play football, he would be very good because he could fly. This would let him put force on your head, and that would knock you over much more easily. As football players we cannot fly. We're both stuck on the ground. So we don't have the luxury of pushing with our greatest force at 90 degrees. 

Imagine a door on a hinge. The handle is the farthest from the pivot point. Secondly, you would never grab the handle and push towards the hinges. The door would not open because the hinges are affixed to the wall. This is like a very tall football player pushing down on a small football player. If he pushes downwards, he may be bigger and stronger, but the big football player has no leverage what so ever, and the smaller player is basically pushing upwards, essentially squatting the weight of the larger football player. If he instead pushed on the smaller football player's shoulder pads he would be more perpendicular to the lever arm, and he would start to drive the player backwards instead of pushing him into the ground. This is why youth football coaches everywhere teach the bear crawl. If a player is very low to the ground it is virtually impossible to move him backwards. The bear crawl tactic shortens the lever arm and makes it harder to push the player backwards. It also gives them lots of balance. Like I said before though, you could just push him down and very easily block him with one person. Some coaches also recognize that if the opponents are bear crawling they may literally not contribute to the play, so I've even heard of some coaches leaving bear crawlers unblocked.

So does the low man win? The low man implies that you want to put the maximum amount of force upwards into your opponent. Like I said earlier, the maximum force applied is at 90 degrees, and we can't do that, but we can apply force at an upwards angle. Imagine two hardcover books that are stood upright and parallel to each other. Now let them drop and fall towards each other. The book that manages to get underneath the other is going to prop the other book up. You can demonstrate this to yourself by exaggerating the angle that you hold the book before it drops. Hold one closer to the ground. It will always win. The one that is more upright will always be pushed backwards. So the low man wins, as  long as he's balanced. If your opponent knows how to unbalance you, then the low man might just lose.

Finally, you can redo the book demonstration with an angle block. The other important lever in football is your shoulders. If you are square to the line you can much more easily tackle a runner, and you are a much harder obstacle to overcome. However, if you mindlessly square yourself to the line, you are vulnerable to an angled block. With the books this becomes very clear. Defensive players will learn throughout a game that a down block is coming, and they will instinctively meet the down block head on. Often times defensive players will make the mistake of trying to go over a down block, which only makes a larger hole in the defense since it leaves an uncovered gap where they were. The correct technique is to push back against the down block while trying to stay square. They should try to create distance with their arms or try to drive the offensive lineman backwards. They should do this without leaving their gap unless they know they can get a tackle. 

Deaths while walking 4,743Deaths from football 12


Coyote, mahonz, Bob Goodman and 1 people liked
Quote
gumby_in_co
(@gumby_in_co)
Platinum
Joined: 11 years ago
Posts: 4296
 

When I use the term "leverage", I am describing positioning of a blocker or defender in relation to other players or an area of the field. It has little to do with mechanical leverage in the practical sense, but more in the metaphorical sense.

One of the definitions of leverage:

"The power to influence a person or situation to achieve a particular outcome."

This is only my guess, but I think the origin of this definition is using a particular advantage is akin to using a lever. For example, in negotiating, having embarrassing details about the other party can be used "as leverage" to help influence the outcome of the negotiation. This is similar to how one would use an actual lever to move a heavy object.

So when it comes to football, one's relative position to another player can influence the outcome of that particular 1 on 1 battle. 

One example would be a force defender maintaining outside leverage on blockers. This means positioning himself to the outside of the blocker and maintaining that relative position to influence the ball carrier to run inside.

Another example would be down blocking schemes. You are directing your linemen to block to their inside, which gives them immediate outside leverage on the defenders they encounter. When the ball carrier then moves to the outside, the defenders are at a disadvantage because to pursue the ball, they would have to go through a blocker. However, in an off-tackle play, you combine the outside leverage of down blocking linemen with the inside leverage of a kick out or wham block. This is to take advantage of the force defender's insistence on maintaining outside leverage. Rather than try to battle him for outside leverage, you concede that and take advantage of the space the down blockers created to the inside. This is done due to the belief that a reach block is relatively difficult to execute. Instead, take the approach that has a (perceived) higher chance of success.

One more involves the alignment of defensive backs. A CB may align inside a receiver (inside leverage) to deny inside routes, or may align outside (outside leverage) to deny outside routes. So a CB aligned inside of a WR can use his relative position to influence the outcome of that WR running a slant, post or any other inside route.

This is why I never use the word "leverage" with my players. 

 

When in doot . . . glass and oot.


ReplyQuote
Coach Kyle
(@coach-kyle)
Platinum
Joined: 11 years ago
Posts: 3826
Topic starter  

@gumby_in_co

I understand that use of the word. The human body is full of levers. The phrase "low man wins" is referring to how forces apply to lever arms, and it is counter intuitive. 

I think I'm going to do a video on this. I'll add in some other tips that become really obvious when you see it demonstrated. I just need to find a way to draw on my computer screen.

 

Other things are really obvious like the positioning of the feet and hand placement. Also the condensing of the arms and legs is important.. There is a great video of some Oklahoma drills where you can really see the concepts at work. You can also see how fast things change in terms of who has the advantage.

 

Deaths while walking 4,743Deaths from football 12


ReplyQuote
Coach Kyle
(@coach-kyle)
Platinum
Joined: 11 years ago
Posts: 3826
Topic starter  

@gumby_in_co

 

I also don't think this type of stuff should be taught or mentioned to the players. This is for coaches. 

I'm also not saying to stop using your definition of the word... obviously 

 

Deaths while walking 4,743Deaths from football 12


ReplyQuote
gumby_in_co
(@gumby_in_co)
Platinum
Joined: 11 years ago
Posts: 4296
 

@coach-kyle

Yes, and you are 100% correct that "leverage" can be used to describe the use of actual levers in an engagement. I should have clarified that the definition I provided was 1 more use of the word. I actually struggled with it. I used the term all the time, I knew it when I saw it, but couldn't really define or explain it. Your post gave me the opportunity to really think about it.

Some time ago, DP and I were going back and forth about how he would not widen out a defense to accommodate mega splits. My counter to that, was by not moving with us, he was giving us leverage. It then becomes a question of whether or not we can cover enough distance quickly enough to take advantage of that leverage. Failure to do so is a free shot to the ball carrier. 

We play a team every year (sometimes twice) and we have not yet beaten them. This year we came close. They have a Mike who is small, fast and ferocious that they love to put in the A gap. He wreaked havoc on us for 3 years. Last season's game was the first time we were able to neutralize him and we lost 24-18. This was largely due to the leverage advantage we took. One of their best tacklers was in the A gap. We ran to the C gap. He had a body on his outside shoulder making it just about impossible to adjust and get to the C gap. 

 

When in doot . . . glass and oot.


ReplyQuote
Coyote
(@coyote)
Bronze
Joined: 1 year ago
Posts: 250
 
Posted by: @coach-kyle

Everything about the techniques you create or use should be done to maximize these three concepts. 

Coach,  

This is good stuff, - when I took Bio-Mechanics we spent a lot of time working on the idea of keeping the center of gravity inside the base (the 3 points of the triangle you describe), basically walking is moving the center of gravity outside the base and catching it before we fall...  WMU had a new toy back then, measuring ground effects and the head of the dept. had had 3 sons who wrestled (2 state champs) we knew each other before I took the class, we talked about using it to study center of gravity in various throws.  [circumstances interfered, I didn't get to participate in the study] 

A lot of what we do in football is about controlling the opponents center of gravity and/or causing them to move it outside their base, in which case they hit the ground.   

I'm going to copy your post and share with my coaching partners.  You'll get full credit. 😀 

Enjoyed the read and was reminded of things I used to know... Thanx. 

Umm.... why does that 6 ft tall 9 yr old have a goatee...?


ReplyQuote
Share: