Blog #14 - Functional Back Lines

by Joe LaCaze July 27, 2022

The Functional Back Line is your third installment of the six basic motion chains of the body.

This line includes the relationship between two of the strongest and most functionally powerful muscles in the body – the glutes and lats.

Since the gluteus maximus attaches to the femur, and the latissimus dorsi attaches to the humerus, the functional back line is involved in every action where both the arms and legs work together.

If you look at the graphic above showing the functional back line you see that both the glutes and lats attach directly into a white ligamentous type of structure that is called the thoracolumbar fascia (TLF). This is a part of the body that relatively few people know much about, but it is one of the most important structures in the body.

The TLF is about the consistency of slightly flexible plastic. It does not like to be stretched. It protects what it covers and that is a lot – the entire lumbar spine and the lower part of the thoracic spine. That protection includes all the nerves that come out of the spine in that area, all the nerves that supply energy to the entire lower body – to the lower back, hips, thighs, knees, calves, ankles, and feet.

It is so important for the glutes and lats to be flexible, strong, and healthy so the TLF has equal tension on all four sides of it – essentially four different sides of its diamond-like shape.

If the TLF feels unequal pull from one of its four sides, it will automatically tighten to redistribute the tension. Then everything that attaches into it and under it becomes tighter. This is one of the major causes of low back pain and sciatica, two of the most common complaints about the body.

Performance wise, the glutes and lats working together are major contributors to all seven components of athleticism: Flexibility, Speed, Strength, Balance, Coordination, Agility, and Ambidexterity.

However, it is very short sided not to realize they are cross connected (the left lat works together with the right glutes, and vice-versa). Just strengthening and stretching these two sets of muscles is not nearly enough. We must work them both together, against resistance, to strengthen patterns of movement in a cross pattern.

A cross pattern is the way these muscles work anytime we are doing anything that involves using both our arms and legs at the same time. This includes swinging, hitting, throwing, sprinting, punching, kicking, punting, walking, etc.

What are the Functional Back Lines in relation to the skeleton?