The Sagittal Plane and Cross Syndromes

To describe anatomical movement, the body is divided into 3 planes, the sagittal, frontal, and transverse. These may also be referred to as the longitudinal, coronal, and axial planes respectively. Each of the planes is used to define anatomical movement and is based in the anatomical position. If we look at the hip, hip flexion and extension occurs in the sagittal plane, hip abduction and adduction occur in the frontal plane, and hip internal and external rotation occur in the transverse plane. To say that a movement occurs in a plane means that as the hip is flexed, the distal segment moves parallel to that particular plane. As with a lot of medical and anatomical teachings, this is not necessarily true. Movements rarely have true anatomical movement meaning that if a hip is flexed, there are likely movements in the frontal and transverse plane in addition to the sagittal plane.

3 planes of motion

The point is that movement can be described using the tri-planer system (sagittal, frontal, and transverse) although it's not completely representative of actual movement. The reason I introduced tri-planer movement is to focus on the sagittal plane and examine Janda's Cross Syndromes.

The sagittal plane is the plane that divides the body into left and right which allows us to look at movement from an anterior (front) to posterior (back) perspective. If we consider the major joints of the body in the sagittal perspective, we see that most of the joints perform flexion and extension thus moving segments anteriorly and posteriorly in the sagittal plane.

Movements in the sagittal plane

The Cross Syndromes identify patterns of tightness and weakness in the sagittal plane that lead to dysfunction in the body. The Cross Syndromes are probably the most known work of physician Vladimir Janda. They are named the Lower Cross Syndrome and Upper Cross Syndrome and pertain to the pelvis and the shoulder girdle respectively. Before describing the syndromes, there needs to be an understanding of the 2 types of dysfunctions that Janda identifies. The muscles (and associated fascia) that surround the tissues are described as either "tight" or "weak." 

Janda's Cross Syndromes

In the Cross Syndromes, the anterior inferior (front, bottom) and posterior superior (back, top) portions are "tight" while the anterior superior (front, top) and posterior inferior (back, bottom) are "weak." The pattern creates a cross, leading to the syndrome's namesake. To treat this clinically, it is important to understand the anatomy of each of these sections (anterior inferior, posterior superior etc.). However, generally this can be assumed that the hip flexors and low back extensors are tight while the core muscles, glutes, and hamstrings are weak. In the upper cross, the chest and neck extensors are tight while the deep neck flexors and scapular muscles are weak.

I hope that you notice there are a lot of assumptions made here which I will discuss later. For now, it is important that you understand what the sagittal plane is, what general motions occur in the sagittal plane, and what general structures are "tight" or "weak." I find this much easer to digest visually. If you have questions please reread the material and/or reference the pictures before continuing.

Now that we understand the sagittal plane and know the cross patterns, we need to understand how they lead to issues which allows us to treat them. The key here is balance. The body forms a series of balance systems sometimes referred to as the length-tension relationship. I wrote a post about tensegrity that explores the complex system the body utilizes for movement. When considering the Cross Syndromes, we are only looking at the sagittal plane and are thus only considering the anterior to posterior balance of tension. In other words, there is an ideal and balanced tension between the anterior and posterior body for movement. The tension of the tissue of the front of the hips and thighs needs to balance with the tension of the tissue of the posterior hip and thigh. 

The cross syndromes describe tissues as being "tight" which throws off this balance. The off set of balance leads to inability of the tissues to perform adequately. Since the body is very interconnected, the imbalance can effect the whole system. 

Let's look at an example. According to the Lower Cross Syndrome, the hip flexors and quadriceps are "tight" while the glutes and hamstrings are "weak." The tightness from the anterior structures and the weakness from the posterior structures causes a motion called anterior pelvic tilting. This in turn lengthens the hamstrings requiring a longer distance for hamstrings to contract for normal movement. This may cause increased demand on the hamstrings leading to hamstring issues. Furthermore, the anterior tilt of the pelvis makes it harder for the glutes to extend the hip which may put more stress on the hamstrings. In this example, you can see why chronic hamstring issues that are treated with stretching may be leading to the problem. The tissue is already stretched!

Examples of pelvic tilts

What is the solution? Following the ideas of the Cross Syndromes, you simply stretch the "tight" muscles and strengthen the "weak" muscles. In our example above, I would stretch and use soft tissue treatments on the quads and hip flexors while I strengthened the hamstrings and gluteal muscles. I would also add core exercises to create a stable base. 

Imbalance from the Lower Cross Syndrome

Here is the caveat to all of this...I believe this is an analogy based on assumptions designed to give clinicians a roadmap for evaluation and treatment, and not a physiological process. There are a lot of assumptions made about the Cross Syndromes. For instance, an athlete that presents with the Cross Syndrome Pattern is assumed to have "tight" and "weak" muscles in the corresponding areas. Are these muscles really "shorter" than they should be or "longer" than they should be? I don't necessarily think so. Also, just because someone presents with a posture, does not mean that they can't move out of that posture when needed. If the opposite of a "tight" muscle is "lengthened" then the opposite of a "weak" muscle must be "strong" correct? Knowing the physiology of muscle contractions, I don't believe this to be true either. There is an optimal length in muscles that produces the most force that is neither too long or too short. Finally, the Cross Syndromes only consider the sagittal plane while true movement occurs as a complex combination of the three planes.

I do not mean to undercut the importance of the Cross Syndromes. I utilize Janda's philosophies as roadmaps for many of my clinical treatments and I think starting with controlling the sagittal plane is foundational to better movement. I just want to point out some limitations to promote critical thinking. I am an advocate for evaluating and not assuming. The Cross Syndromes assume limitation. Evaluate that assumption! Can the athlete perform the movement appropriately? Is there adequate range of motion? How does it feel? I advise using the Cross Syndromes as a roadmap for where to go.

This post had a lot of information and a few side quests so I'd like to sum up as best as I can. Anatomical movement is described using anatomical planes. The sagittal plane describes anterior and posterior movements. Imbalances in the anterior and posterior body can lead to dysfunction and injury. Janda's Cross Syndromes give us a common pattern for this imbalance. Treating the imbalance by stretching and strengthening certain areas may help to perform better and rehabilitate injury. This is a great place for clinicians to start and an interesting concept for athletes to understand. That's all for now...from the training room.