Breathing is a fundamental human function, yet many of us don’t think about how the mechanics of our breathing can impact our overall health and movement quality. One of the key players in this process is the internal oblique muscle. While often overlooked in favor of more glamorous muscles like the rectus abdominis or the external obliques, the internal oblique plays a crucial role in maintaining proper rib cage positioning and facilitating optimal breathing patterns. Understanding the function and importance of the internal oblique can help prevent common postural issues such as rib flare, improve movement quality, and reduce the risk of injury.

The Role of the Internal Oblique in Rib Cage Positioning

The internal oblique is a deep abdominal muscle that runs diagonally from the lower ribs down to the pelvis. It is responsible for several important functions, including trunk rotation, lateral flexion of the spine, and stabilization of the core. However, one of its most critical roles is in controlling the position of the rib cage.

When the internal obliques are functioning correctly, they help draw the lower ribs down and inward, which creates a more stable and aligned rib cage. This alignment is crucial for proper diaphragm function, which is the primary muscle responsible for breathing. The diaphragm works most efficiently when the rib cage is in a neutral position, allowing for full expansion of the lungs and optimal oxygen exchange.

Understanding Rib Flare

Rib flare occurs when the lower ribs protrude outward, often as a result of weakness or dysfunction in the internal obliques. This condition is characterized by an exaggerated arch in the lower back and an elevated rib cage, which can significantly disrupt the natural breathing pattern. Rib flare is not just a cosmetic issue; it has serious implications for both movement quality and overall health.

When the rib cage is flared, the diaphragm cannot contract properly, leading to shallow breathing patterns. Shallow breathing, in turn, can cause over-reliance on accessory breathing muscles like the neck and upper chest muscles, leading to tension, pain, and potential injury in these areas. Additionally, a flared rib cage often leads to a hyperextended lumbar spine, increasing the risk of lower back pain and compromising the stability of the entire core.

Implications for Movement Quality and Injury Risk

The alignment of the rib cage has a profound impact on movement quality. A neutral rib cage allows for better control of the spine and pelvis, enabling more efficient and coordinated movement patterns. Conversely, rib flare can lead to dysfunctional movement patterns, as the body compensates for the misalignment. This compensation often results in excessive stress on the lower back, hips, and even the knees, increasing the risk of injury during physical activity.

The exaggerated arch in the lower back can cause the pelvis to tilt anteriorly, leading to poor hip mechanics and increased strain on the lumbar spine. Similarly, during overhead movements, a flared rib cage can limit shoulder mobility and stability, potentially leading to shoulder-related injuries.

The Connection Between Breathing and Core Stability

Breathing and core stability are intimately connected, and the internal obliques play a central role in this relationship. Proper breathing mechanics require a coordinated effort between the diaphragm, internal obliques, and other deep core muscles, such as the transverse abdominis and pelvic floor. When these muscles work together, they create intra-abdominal pressure, which stabilizes the spine and pelvis during movement.

However, when the internal obliques are weak or inactive, this delicate balance is disrupted. The inability to draw the ribs down and inward compromises core stability and forces the body to rely on superficial muscles for support. This not only increases the risk of injury but also leads to inefficient movement patterns that can hinder athletic performance and everyday activities.

Strengthening the Internal Obliques for Optimal Rib Cage Positioning

Retraining the internal obliques is essential for correcting rib flare and optimizing rib cage positioning. A well-balanced core training program should include exercises that specifically target the internal obliques and promote proper breathing mechanics and positioning of the rib cage.

The 3-month supine position is important from a developmental standpoint as it enhances the function of the internal oblique, diaphragm, and overall core stabilization. To perform this drill, the individual lies on their back with legs elevated, mimicking the developmental posture of a three-month-old infant. This position encourages proper diaphragmatic breathing and activation of the deep core muscles, including the internal obliques, as the ribs are drawn downward and inward with each exhale.

Here is a video by Dr. Mitch Israel performing this drill…

Although it looks simple, and certainly not your typical “strengthening” exercise, it’s important from a foundational standpoint cannot be overlooked. Once the drill above is mastered with proper positioning of the rib cage, spine, & pelvis, and diaphragmatic breathing, harder variations can be utilized by transitioning from the supine 3-month to 6-month position, and/or reaching the upper extremity, lower extremity, or both simultaneously. These resemble the common dead bug variations, however, emphasis must always remain at maintaining position of the canister and breathing at all times.

In the following video, Dr. Beau Beard demonstrates how to transition from the 3-month to 6-month developmental position…

Conclusion

The internal oblique is a key player in maintaining proper rib cage positioning and optimizing breathing patterns. Weakness or dysfunction in this muscle can lead to rib flare, compromised core stability, and an increased risk of injury. By incorporating exercises that specifically target the internal obliques and promote proper breathing mechanics, individuals can improve their movement quality, enhance athletic performance, and reduce the likelihood of injury. Whether you're an athlete or someone looking to improve your overall health, paying attention to the function and strength of your internal obliques is essential for achieving your goals.

Do you have questions on how Dynamic Neuromuscular Stabilization (DNS) can you help improve core stabilization, restore proper breathing patterns, or improve performance? Contact Garrett to talk more and let’s customize an exercise plan to your needs!