Archive for June, 2012

Pectorals Vs. Rhomboids: Tug of War Between 2 Muscle Groups

Thursday, June 7th, 2012

Have you ever taken the time to observe the way people move?  As a massage therapist,  I am constantly watching how people walk, sit and stand.  This includes an examination of postural distortions and one’s gait (the pattern of movement of the limbs.)  Over time, I have discovered a very common condition that is affecting most people that I see.  It seems as though humans are actually evolving backwards in this day and age.  Although I may be half-joking with the previous statement, there is much truth in it.

Modern humans evolved from the last common ancestor of the Hominini some 2.3-2.4 million years ago in Africa.  This species came from the genus Homo, which was preceded by primates such as gorillas and chimpanzees.  So its safe to say that we evolved from such mammals.  But have you ever seen the way a gorilla or chimpanzee sits or walks?

The illustrations to the left show a gorilla sitting down, and a chimp walking up a tree limb.  I see an exaggerated mimic of bad human posture.  Of course, you must keep in consideration that these animals do not typically walk upright like humans do, but I see some similarities between these monkeys and today’s human species.

Notice how the gorilla has his shoulders completely rolled forward and the chimpanzee is completely hunched over with his head and neck forward and down.  This may seem like a silly analogy but just look at the illustration below.

This posture is very commonly seen today, and wouldn’t you say it resembles the pictures above? Many people are not very observant of their own posture, which can be dangerous for our skeletal structures and muscles.

Because humans are an upright animal who walks on 2 legs instead of 4, it is ideal to have an upright posture.  When posture is not upright, we start to experience all kinds of dysfunction in the body.

For now, let’s focus on a dysfunction of the shoulder girdle that occurs when our structure starts to look like the photo to the left.

This common dysfunction in the body occurs between the Pectoral muscles and the Rhomboid muscles.  The Pectoral muscles consist of the Pectoralis Major and Pectoralis Minor and they lie on the front of the chest.

The Pectoralis Major attaches at the anterior surface (front side) of the clavicle, and the anterior surface of the sternum.  It inserts at the lateral side (outer side) of the humerus.

The Pectoralis Minor (pictured to the left) is a thin, triangular muscle, situated at the upper part of the chest, beneath the Pectoralis Major.

The Pectoralis Major/Minor are the major muscles of the anterior chest.  Now lets talk about the opposite muscles (antagonistic) muscles to the Pectoralis muscles.  The antagonistic muscles perform the opposite action of any given muscle, and the opposite of the Pectoralis muscles are the Rhomboids and Trapezius muscles.  Below is an illustration of these.

The Rhomboids (left) consist of a major and a minor just like the Pectoralis muscle.  The major arises from the thoracic vertabrae (mid-spine), and inserts on the medial border of the scapula.  It also lies deep to the Trapezius muscle that is pictured to the right of the Rhomboids. The Rhomboid minor sits superior (above) to the Rhomboid major.

The Trapezius muscle, as you can see, is much larger than the Rhomboids and is wing-shaped.  This muscle is unique in that it attaches where the base of the skull meets the neck, called the Occiput. and ends all the way down by the Lumbar spine.  Also, this muscle, being as large as it is, has 4 separate heads.

So what exactly is this tug-of-war that occurs between the anterior and posterior muscles?  The Pectoral muscles are much stronger and larger than the Rhomboids and Trapezius muscles, and consequently, in this tug-of-war, the Pectorals beat out the back muscles.  One of the most common postural distortions is when people roll their shoulders forward shown in the blue illustration above.  This causes the back muscles to become overstretched and the chest muscles to become locked short.

When this dysfunction occurs, it is common for people to feel pain in their shoulders and neck.  And many massage therapists will overwork the back area to try to loosen up the muscles.  But if they were to observe the Pectoral muscles, they would notice that this is where the tightness is actually occurring.  Why would you need to perform deep tissue massage on the back muscles when they are already overstretched?  The work must be done on the Pectoralis muscles in the chest.

Massage therapy is a great remedy for this imbalance in the body, but there are also many exercises that you can do to help strengthen your back muscles.  For the Rhomboids, try pushing your shoulders back, imagining that you are squeezing your shoulder blades together.  Also, you can extend your arm out away from your body at a 90 degree angle and perform arm circles, moving forwards for a few minutes, then backwards.  For the Trapezius muscles, shoulder shrugs with weights are a great way to strengthen the shoulders. And to help with the shortened Pectoralis muscles, stand in a doorway with your arm over your head, holding onto the door frame, and lean forward.  This stretches out these muscles that are constantly in a locked state.

If you or anyone you know are experiencing back and neck pain/stiffness, please give me a call today in Salt Lake City, Utah at 801.349.3934 to schedule your first appointment.  As mentioned earlier, massage therapy is a great way to heal and prevent the tug-of-war that is constantly going on in your shoulder girdle.