In Parts 1, 2 and 5 of the Anatomy For Athletes Mini-Series I discussed the importance of developing glute, hamstring and calf strength.

What do the glutes, hams, and calves have in the common with the muscles we’ll discuss today?  They’re part of the posterior chain.

A strong posterior chain is important for athletic performance, alignment, posture, and injury prevention.

This post, along with parts 1, 2 and 5, will provide you with all of the resources necessary to develop a strong posterior chain.

How To Design Your Own Training Programs

Functional Anatomy of the Intrinsic Back Muscles

The table below outlines the origin, insertion, and function of the intrinsic back muscles.

Anatomy of The Intrinsic Back Muscles

It looks daunting, I know, but don’t let it intimidate you, I’ll simplify it in the paragraphs that follow…

The Erector Spinae

All of the muscles included in the chart, with the exception of quadrates lumborum and multifidus, combine to form the erector spinae (highlighted in blue).

The erector spinae run the length of the spine, from the sacrum to the base of the skull.  When working unilaterally, the erectors laterally flex the spine and head (i.e. side bending and brining your ear toward your shoulder).  When working bilaterally, they extend the spine and head (i.e arching your back, leaning backward, or tilting your head back).

The erector spinae can be broken down into three different groups based on their insertion point.  And each group can be further subdivided based on which area of the spine they act upon.  The chart below provides a breakdown of the insertion point and site of action for each erector muscle.

Erector Spinae Muscles

Considerations For Training

Exercises for the erector spinae can be subdivided into three groups:

  1. Bilateral:  When the erector muscles all fire in unison, their net action is to extend the entire spine.  Extension variations like deadlifts, good mornings, reverse hypers, back extensions, and supermans work this function.
  2. Unilateral: To isolate one side of the erector group, trunk extension mush be combined with rotation.  Exercise examples include superman with rotation and back extension with rotation.
  3. Isometric:  Isometric exercises like isometric back extensions and reverse planks work the spinal stabilization function of the erector group.

(I’ve included a few exercise demonstrations videos at the end of the post.)

Now that you understand which exercises to include to train your back extensors, let me outline a couple key points…

The best way to develop both the strength and size of your erector muscles is to deadlift.  Deadlifts allow you to move a greater load than any other back extension variation and they’re also far more functional — i.e. they translate into gains in both sport and everyday activities.

When performing any of the exercises listed above, MAINTAIN A NEUTRAL SPINE throughout to reduce your risk of injury.  (There are round back variations of many of these exercises, but they’re better suited to advanced lifters — like competitive powerlifters — and should be done under the supervision of a qualified strength coach, physiotherapist or athletic therapist).

Quadratus Lumborum

The primary function of the quadratus lumborum (QL) is lateral flexion (side bending) of the trunk (along with the internal and external obliques).  It also contributes to trunk stabilization.

A strong QL allows you to squat, pull, and overhead press more weight.

However, if there’s a side-to-side imbalance (i.e. your QL on one side is tighter or stronger than the other), it can cause misalignment of your pelvis and contribute to lower back pain.  Self-myofascial release exercises like foam rolling or lacrosse ball smashing can be used to reduce QL tightness.

Examples of QL Exercises Include:

  • Side bend variations
  • Windmills
  • Bent Presses
  • Saxon side bends

(I’ve included a few exercise demonstrations videos at the end of the post.)

Considerations for Training

In order to target your QL (and internal/external obliques), include lateral flexion exercises in your programming.  When performing these types of exercises be sure to maintain a neutral pelvis.

It’s also important to include flexibility, mobility and self-myofascial release exercises for the QL to prevent lower back pain and/or pelvic alignment issues associated with QL tightness and imbalance.


The multifidus is a deep muscle located along the back of the spine.

It functions — along with the transverse abdominis and pelvic floor muscles — to stabilize the spine and pelvis before movement of the arms and/or legs.  When the multifidi fire bilaterally they assist with spinal extension and when they fire unilaterally, they assist with lateral flexion and rotation.

The example exercises provided in the erector and QL sections above also work the multifidus.

Considerations for Training

Weakness or poor activation of the multifidus can contribute to lower back pain and issues with spinal / pelvic stability.

A physiotherapist can help address these issues with breathing, activation and strengthening exercises.

Intrinsic Back Muscle Exercise Examples

Well there you have it, functional anatomy and training of the intrinsic back muscles.  Be sure to combine the tips presented in this article with those in parts 1, 2, 5 and 6 when developing the posterior chain and core training components of your programs.

Next up: Anatomy For Athletes — Part 8 — Upper Back Muscles...Check back in a few days…

Want to design your own training programs?

Click the image below to download The Program Design Guide and Templates for free.


How To Design Your Own Training Programs

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