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What Your Ribs Can Tell You About Squatting and Deadlifting

Updated: Jul 8, 2023

This past weekend, I was fortunate enough to attend a course in Pennsylvania called The Human Matrix: The Code for Maximal Health and Performance by Zac Cupples. Now you may be saying, “Wow that’s quite an ambitious name for a weekend course”. I went into it agreeing with you. However, I came out of it with a new found appreciation for how to look at the human body and what it is capable of doing.

What I most appreciated about the course was the logical train of thought that it involved. We started by going over some concepts, learned some assessments, and then finished with exercise prescription. Everything was explained in ways that made sense and provided actionable suggestions that will improve my clients’ care. Let’s break down the important factors.

First, we need to understand one of the main facts about the human body: it is mostly water. So if we look at each segment of the body as a tube containing water, we can more easily understand movement restrictions and compensations. The first use of this concept is in regards to your breathing patterns and how they affect the rest of your body. A simple test we used to start was looking at infrasternal angle (ISA). Your ISA is the angle made under your rib cage.

ribs breathing mobility physical therapy strength training

Everyone has a different ISA based on the way their body brings in air. You either have a narrow ISA (less than 90 degrees) and breathe more through the front and back of your ribs or a wide ISA (more than 90 degrees) and breathe more through the side of your ribs.

Now that information about how you breathe is interesting and maybe a good party trick, but what does that mean for you? Well, it turns out that your body will make significant compensations based on your breathing pattern, including your sacrum.

It turns out that if you have a wide ISA, then your sacrum will be nutated or tipped forward. The reverse is true for a narrow ISA. Now we are getting to some of the most interesting consequences of your breathing pattern. Look at these two common exercises in the gym, the squat and deadlift.

squat weightlifting strength training injury prevention wide ISA
Everkinetic, CC BY-SA 3.0 <>, via Wikimedia Commons

deadlifting low back pain physical therapy narrow ISA
Everkinetic, CC BY-SA 3.0 <>, via Wikimedia Commons

We actually broke down the squat in detail at the course and talked about how a lot of people are doing it wrong (also with the deadlift). However, we will leave that for another time. The main point of looking at these two major lifts is paying attention to the pelvis and how it moves. If you imagine yourself squatting, it is a mostly vertical movement where the pelvis has to descend as far as you are able. In doing so, it will naturally posteriorly tilt (tipping your back pockets down to your heels).

The deadlift is the opposite motion. While you should strive to keep your pelvis “neutral” or stacked as Zac calls it, it will tilt slightly anteriorly (front of your hips toward your toes). These are not large movements, but they do occur. When we are dealing with the pelvis, a few degrees make a large difference.

So, remember back to when I mentioned that wide ISAs have a sacrum that is tipped forward while narrow ISAs have a posteriorly-tipped sacrum. Squatting involves sitting into that posteriorly-tipped sacrum, meaning that narrow ISAs will have an easier time with the mechanics. Wide ISAs will naturally be tipped forward and will have an easier time pushing their hips back to extend their back for a deadlift.

Now the real question, why does this matter? It matters because if we understand how we move, we can better look for compensations. It can also guide programming decisions, meaning if someone with a narrow ISA comes to me, I can assume that they will have a better time learning to squat and may be able to progress that motion more rapidly. I will also know that if someone with a wide ISA comes to me claiming they can squat really well, I better double check their motion to make sure they are maintaining good positions. These are all steps that I would take with all clients, but the more that I can tailor my assessment and exercise prescription, the easier it is for everyone involved.

Thanks for reading and I want to thank Zac for an awesome course. If you are interested in what he has to say, his website is and you can find a bunch of good information on there!

Are you in the Sterling, Virginia area and interested in working with me for physical therapy, injury prevention, or performance enhancement? Email me at and let's help you reach your goals!

Written by Danny Lehnert PT, DPT, OCS, CSCS, CDN, BRM

Instagram: @drdannydpt

Twitter: @drdannydpt


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