We get some great questions from people when they ask about the throwing motion. “How do I throw the ball further?” “How can I improve my accuracy?” What is the most important area of the body for a QB to improve his throwing motion?” The more that I get these questions, the more I realize that coaches and players don’t understand the important relationship between all three of these questions. Today, I will go in depth about the importance of a super critical area of the body and how improving this area will AUTOMATICALLY clean up accuracy and increase power.

What Defines “The Trunk?”

When most of you think about the abdomen, you automatically think about the “6 pack” muscle called the rectus abdominis. The truth is that there are many muscles that make up “the trunk” that play an essential role for quarterbacks when playing the position. These muscles make up a funnel that when braced properly acts as a firm object to move from. The key words here are “braced properly” because many athletes don’t know how to perform this correctly. Here are the muscles of the trunk and where they are located within the body.

  1. Diaphragm- the top of the pelvic funnel
  2. Internal and external obliques- the sides of the pelvic funnel
  3. Transverse abdominis- the mini funnel that wraps around
  4. Rectus Abdominis- the front of the pelvic funnel
  5. Pelvic Floor- the bottom of the pelvic funnel
  6. Erector Spinae- the back of the pelvic funnel

So you are telling us that these muscles are working simultaneously at all times to be able to stabilize the “lumbo-pelvic” area of the body for proper function? That’s exactly what I am saying. To go a step further to enhance knowledge of these muscles because it is so important, there are pictures of all of them below.

Can you get the three dimensional image in your head of how these muscles would form a funnel now? I hope the answer is yes because we are now going to look at the throwing motion and how they relate.

The Loading Phase of the Throwing Motion

I want you to hang with me now as this will start to get a little more in depth on how the trunk relates to the throwing motion. The first thing I want to say is that during the throwing motion, the role of the trunk is to stay in an extremely “stable” position during the whole motion. The reason for this is to translate the forces that are being created from the hips to the torso. I want you to view the trunk as the road that translates power from the lower body to the upper body. It’s just that simple.

Now let’s take a look at the first phase of the throwing motion: the loading phase. During the loading phase of the throwing motion, the hips are essentially going one way while the torso goes the other way. What does this mean for “the trunk”? Ideally, we would want the trunk to continue to stay in a stable position, but there could be some big time problems that can effect this stable/neutral position. Let’s list these out.

1. Lack of Thoracic Spine Rotation

The upper part of the spine, the thoracic spine, is meant for rotational movement during the throwing motion. The lower part of the spine, the lumbar spine, is meant for stabilization during the throwing motion. This is such a key concept! No two quarterbacks will present the same from a physical standpoint, so a quarterback could lack some thoracic spine range of motion capability that can cause a compensation strategy during the loading phase of throwing. The most common compensation that we see is over extension of the lumbar spine. What happens during over extension of the lumbar spine you might ask? Well, we lose that stable trunk position that we were talking about above which is so essential to have during the entire throwing motion.

2. Lack of Hip Internal Rotation Range of Motion

We did a long blog post on that last week so I will provide the link here so you can get a more in depth view of what we are talking about.


Essentially, when the hip doesn’t internally rotate during the late loading phase for a QB, the leg will essentially trail the rest of the body. This disconnect from the hips to the trunk causes a big loss of the force that is being generated from the ground. Because the hips can’t get in a position to extend now during the acceleration phase, they won’t. Whenever you hear that a quarterback “uses his arm” to throw, this is the picture I want you to have in your mind. This disconnect is something that thousands of quarterbacks all over the country deal with their entire careers. I know us Kiel brothers all dealt with this and never understood why we could never increase velocity on our throws. Check out the video below to understand more about this term we call “trailing leg syndrome.”

3. Lifting of Shoulder in Pre Pass Position

It is also very common for quarterbacks to cock their shoulder up in their pre pass position which is an improper position to start in when trying to generate force forward. This minor malfunction in positioning matters a lot because when a player is moving from the frontal plane to the sagittal plane through rotation, the body needs to be in a position to stabilize the best to counteract the forces being put through it at high velocity. This is a complex picture to paint, but please watch the video below so we can explain this to you more in depth so you can have a greater understanding.

The Acceleration Phase of the Throwing Motion

Trunk stability or lumbo-pelvic stability is super important during loading phase to maintain while the hips and upper spine rotate to produce power, but it is also very important during the acceleration phase. During the early acceleration phase the body is rotating forward, but it is also starting to incorporate the sagittal plane as well. Quarterbacks now need normal ranges of motion through hip extension and shoulder flexion in order to maintain this ideal, “stable” trunk position. If the don’t, then we know that the outcome is decreased accuracy and decreased power. Let’s talk about these more in depth.

1. Lack of Hip Extension on Drive Leg

If quarterbacks lack hip extension on the drive leg, then we automatically know that there is going to be decreased performance. This is true because of the anatomical nature of the body. If there is a lack of hip extension, we also know that the lumbar spine will have to compensate, therefore losing the trunk stability that we need in order to be successful. It’s a double whammy here for quarterbacks because they lose the proper position to be successful, but the tone that they have in their hip flexors also causes an inability to access the glutes which decreases power output. This isn’t good is it?

2. True Trunk Stability Issue

A lot of the problems that we have presented are mobility restrictions within the body that are causing the trunk to be in an unstable position. Some quarterbacks have a ton of flexibility, but don’t have enough stability during the acceleration phase to be in a good position at the release point. That’s why it is so important to determine if a quarterback is hyper mobile (too much flexibility) or hypo mobile (stiff in nature). For this type of issue, stability will have to be increased for the athlete to be successful. Below is an exercise to use to build trunk stability.

3. Lack of Range of Motion in Shoulder Flexion

This last area is one that is often present, but could be present because of many reasons. There are a lot of muscular and structural components that go into shoulder flexion. Proper thoracic extension through the spine, flexibility through the lats and pecs, and proper control of the scapula all play a role in quality shoulder flexion. When players don’t have proper shoulder flexion, we see the same compensation as before, an over extension of the spine which is detrimental.

Is it really that complex?

Many of you are probably asking that very question and the answer is absolutely. It’s often funny to us when we hear coaches at every level coach their players the same way assuming that all bodies are the same at that current time. Missing a throw high is often times a lot more involved than a coach thinks it is. Not being able to throw the comeback with good velocity might be an impossible feat for some due to the issues. These are examples, but you get what I’m saying. The throwing motion is extremely complex and it should be treated that way. If you are a player or a coach and want to learn more about this or want to hear more about our QB Performance Screen to tease some of these issues out please reach out to us.

-Drew Kiel PT, DPT CSCS