Defend Your Body Against Compression, Shear Forces

Dr. Adrian Pujayana

POSTURAL muscles are over-utilized but often under-developed. Your anatomical framework determines how your body functions under the force of gravity and overload situations. Your body’s postural muscles are a lot like rebar embedded inside concrete. Rebar is short for reinforcement bar, the steel that gives concrete tensile strength. Concrete is very strong under compressive loads but not to shear. The Roman columns are great examples of compression strength but shear weakness. These structures stood the test of time (aka, gravity), but not earthquakes (aka, shearing forces).

Like concrete, our bodies, especially our spinal column, can withstand high compressive forces if it were stacked vertically. But our spine is not arranged linearly, but changes directions at different locations. Gravity will naturally produce tensile forces on the disc and the vertebrae, and this is where your postural muscles are critically important for enduring and functioning under changing tensile forces throughout the day. Here is a short list of the major postural muscles you want to always keep strong:

1) Latisimus dorsi: This is the large muscle that gives your back a “V” shape when developed. This muscle connects your pelvis, lower back and your arms to produce pulling power in addition to stabilizing the spine while you lift.

Best exercises: Pull-ups and machine pull-downs are ideal. Bent-over single- or double-arm rows with a weighted bar are also great. Don’t underestimate the rubber bands when doing rows, as they can really develop endurance without the strain of heavy weights.

2) Posterior delts: These are shoulder muscles, specifically the back of the shoulders. These are essential in keeping your neck and sternum orientation in an upright position, and keeps you from slouching forward.

Best exercises: Like the Latisimus, bent-over rows and rubber-band rows are great techniques for developing the strength, endurance and tone of shoulder muscles.

3) Rhomboids: These are smaller pulling muscles that stabilize the scapula, located at mid-spine level. Having well-functioning shoulders depends on rhomboid-muscle strength, endurance and activation.

Best exercises: Bent-over rows with intentional focus on quality movement will isolate rhomboid muscles. Keeping your scapula in the “set’’ position will improve the activation and development of this muscle.

4) Quadratus lumborum: These are lower-back muscles that are activated when bending at the waist. They are often strained when kneeling or sitting on the floor and reaching, while gardening for instance. Lifting awkward sizes like luggage will also engage these QL muscles, and when tired, the QL muscles will strain under tension.

Best exercises: Planks and limited-range back extensions are ideal only if you can do them without pain. Weighted front squats are great for indirectly activating the QL muscles.

5) Trapezius: These fairly large muscles connect your mid-spine and posterior shoulder muscles to your neck. Well-conditioned Traps reduce the strain on your neck when looking down for long periods.

Best exercises: Upright rows and shrugs performed on a slight pulling angle activate the Traps and other associated muscles. Again, these moves should be done while pain free.

6) Gluteus: There are three different gluteus (buttock) muscles, and all are important and can be activated simultaneously with good form.

Best exercises: I suggest weighted front squats while holding a weight at chest level instead of the back squats (a weighted bar on your neck and shoulders) in order to reduce spinal compression. Your body weight is also an ideal resistance source for squats!

The above muscles are essential but not the only postural muscles you want to develop. If time is an issue, then focus on these muscles using nothing more than a resistance band and your body weight. And remember, movements during any exercise should be pain-free and utilize full range of motion whenever possible. With good planning, it can take as little as 10 minutes to focus on all the above muscles. Good luck!

Dr. Adrian Pujayana has been providing drug-free solutions for health and wellness to adults, athletes and youth since 2000 through his private practice at Family Chiropractic Center of South Pasadena, a place for strength training and nutrition based health care. For comments or questions, email him at