If you’ve dealt with ongoing rib soreness without a clear traumatic injury (such as a slip-and-fall incident), you’re likely dealing with serratus anterior weakness, especially if it extends from the armpit area down towards the bottom of the rib cage. Without knowing what this muscle is or where it’s located, the pain can feel similar to a broken rib (tender to touch) and masquerade as a shoulder or thoracic spine problem. And while one of those issues can certainly be at play, a lack of serratus anterior strength is most likely the root cause of pain.
The “boxer’s muscle” and its serrated appearance
The serratus anterior is aptly named due to its function in protracting the scapula (bringing it forward and away from the spine), much like a boxer’s jab. As you may have guessed, similar to a serrated knife, the serratus anterior has jagged edges that insert into the edges of a rib cage. Think of a steak knife as it cuts into the edge of a juicy steak. Having this fan-shaped function allows the muscle to elevate the ribs, assist with breathing, and keep the scapula against the thoracic cage. Therefore, weakness in this muscle can cause scapular winging. Note: serratus anterior weakness is only one cause of scapular winging, and long thoracic nerve damage can also cause serratus anterior weakness.
Additional functions
In addition to protraction, the serratus anterior assists with overhead arm movements and upward rotation of the scapula. Without assistance from the serratus anterior–especially if the lower trapezius is already weak–accessory shoulder muscles kick in to help keep the shoulder blade stay elevated. Generally, this results in the levator scapula becoming overactive (the muscle’s name literally means “lifter of the scapula”), or the upper trapezius in those who already have a weak levator scapula. And although the levator scapula does elevate the shoulder blade, it’s supposed to be a team effort between the upper and lower muscles, including the serratus anterior.
How to strengthen this muscle
Strengthening the serratus anterior will feel somewhat unusual for those who are used to traditional strength training. The muscle movement patterns are not intuitive. And those who have experienced significant losses in scapular protraction will find serratus anterior exercises quite difficult, at first. The notion of pushing out and away from the wall, or the ground, seems quite simple. But it might be one of the hardest tasks to accomplish. With that said, take these exercises one step at a time, at your own pace (or your client’s) and keep pressing on! Please see linked videos for each exercise.
1. Wall slides
The most basic progression, and the one I recommend starting with, is no equipment. Just your arms, pinkies and forearms to the wall, shoulder-width apart. Position your feet just slightly past shoulder width and your body diagonal to the wall. While pressing your elbows against the wall, push up and away from the wall. This is a tricky movement, so do not progress this to weight until you can properly master this. Once this feels great, use a loop band around your wrists. If you get really good at this, then you can do this with a foam roller under the forearms + the band around the wrists.
2. Pushup plus
This is my favorite exercise because clients find it very easy to engage with, and there are so many variations that are easy to work with. The easiest place to start is on the wall. To properly do this, start with your body angled toward the wall and arms pushed all the way out, with elbows turned down (so the creases are facing up). As you do the “push up,” lower yourself to the wall only using your shoulder blades–no elbows. This movement should only come from the shoulder blades. If this movement feels odd or uncomfortable, start small. Focus mostly on the push away from the wall, rather than the lowering phase. To progress this, you can do this on all 4’s, in a standard push up position, in a tripod pushup position, or unbalanced position (i.e. one arm or leg on a balance pad).
3. Bear hugs
This exercise is a fun and much easier one than the previous two. It feels similar to a standard chest press, so it’s much more intuitive. Rather than the pecs, you want to think of pushing lower–from the rib cage area, and “doming out” your back as you emphasize that scapular pushing motion. This exercise can be done with therabands or cables. Really think of giving someone a nice big hug! Be careful with the weight, however. These can feel easy, but if you increase the weight too rapidly, you can risk injury/re-injury fairly quickly.