The Main Muscles of Movement, Dynamic Alignment & Balance.

by leggi 2mo1st Sep 20193 comments


This follows an introduction to the median plane and our midline anatomy as the references for alignment and balance of the human body.

Now consider the moving body and the muscles that you use.

Do you have a full range of natural movement?

A Full Range of Natural Movement.

A full range of natural movement is what the body should be able to do. The body's full potential. Not what you have got used to!

Movement should be smooth and controlled, the body stable as it glides through an almost infinite number of potential positions. ('almost infinite .. positions' will be expanded in a later post.)

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To have a full range of natural movement, the body must be free of any physical restrictions ('physical restrictions' will expanded on in later posts) that would otherwise hinder it.

The positioning of all midline anatomy on the median plane is achievable when the body has a full range of movement - the body aligned and balanced.

Anatomy of Alignment and Balance (Recap).

The linea alba and nuchal & supraspinous ligaments are linear structures on our midline.

The linea alba and nuchal & supraspinous ligaments are strips of tough connective tissue that we have no direct control over, we can however:

  • Learn to fully utilise the adjacent muscles.

(The pelvic floor and rectus abdominis muscles for the linea alba and the trapezius muscles for the nuchal/supraspinous ligaments.)

  • Become consciously aware of the sensory feedback from our muscles, part of our sense of proprioception, to assess the state of alignment of these structures.

More on conscious proprioception.

So, onto muscles for movement and alignment ...

Background Notes on Muscles:

Muscle Engagement & Activation.

An 'active' muscle is traditionally is described as "contracting", but this implies a reduction in length or decrease in size which is often not the case.

The 3 standard classifications of how a muscle 'contracts' are:

  • Concentric contraction (shortening of muscle tissue).
  • Eccentric contraction (lengthening of muscle tissue).
  • Isometric contraction (muscle length remains the same).

I prefer to use 'activating' and 'engaging' when it comes to discussing the usage of muscles.

(I like 'engaging' but I've had poor feedback. I continue my search for the perfect word - suggestions?!)

Muscle Cells = Muscle Fibres.

Muscles consists of 'hundreds of thousands' (no figures available!) of elongated muscle cells (myocytes) surrounded by connective tissue. These cells are commonly known as muscle fibres.

' Several muscle fibres.

' Cross section of muscle tissue.

Areas of Muscle.

It is important to note that it is not "all or nothing" when a muscle works. Muscles consist of many overlapping areas of potential activity. In an individual muscle, some muscle fibres may be active whilst others are resting - or spasming.

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Voluntary Muscles.

Voluntary muscles are muscles with an action that is under the control of the will.

All striated muscles (except the heart) are voluntary - there is the potential for conscious control if the connection between brain (command center) and muscle is developed.

Test Yourself!

Are you willing to do a bit of self-experimentation and consider how your body moves?

Find the following muscles on your body and see if you can connect with them.

It may take a while for 'activation signals' to to get to the right place, and the ability to fully engage the whole of a muscle comes with practice, so give this experiment time ...

The 5 Main Muscles of Movement.

Rectus Abdominis.

The left and right rectus abdominis muscles run parallel to each other, either side of the linea alba, up the front of the abdomen from pelvis to thorax.

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The rectus abdominis muscles attach to:

  • Pubic symphysis and pubic crest of the pelvis.
  • Costal cartilages of the 5th, 6th and 7th ribs (on the medial inferior costal margins).
  • Posterior aspect of xiphoid process of the sternum.

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The rectus abdominis muscles consists of several 'panels' of muscle between strips of connective tissue known as tendinous intersections.  These sections of muscle are what gives the rectus abdominis the “6-pack” look, but the number of panels can vary between individuals - 4, 8, and 10 packs can occur.

The rectus abdominis muscles sit within their respective rectus sheath formed by the aponeuroses of the lateral abdominal muscles before they merge to form the linea alba. Image text

My comments.

The rectus abdominis muscles - Our core pillar of strength. Our central Line. Strong and flexible, able to support the rest of the body when fully utilised.

Like two stacks of blocks to be activated in sequence from pelvis to chest.

Think longer and stronger with every in breath.

Ribbons of muscle that can bend and rotate at every level.

Fully engaging and elongating the rectus abdominis muscles extends the linea alba (our primary guide for alignment) to its full potential.


The left and right trapezius muscles are the most superficial muscle layer from mid-back (last thoracic vertebra) to the base of the skull, extending out towards each shoulder.

The trapezii (plural) meet midline, attaching to the nuchal ligament and supraspinous ligament. image textThe trapezii are thin sheets of muscle, sculpted down the neck and towards the shoulders, attaching to both scapula (shoulder blade) and clavicle (collar bone) of each arm.

Based on the direction of the muscle fibres, current descriptions split each trapezius muscle into 3 functional sections.

1. Upper trapezius. (a.k.a. superior trapezius, descending trapezius)

Attaches to:

  • Base of the skull. External occipital protuberance and medial third of the superior nuchal line of the occipital bone via a thin fibrous lamina.
  • Nuchal ligament.
  • Lateral third of the clavicle.
  • Spinal process of the 7th (last) cervical vertebra.
  • Supraspinous ligament.

2. Middle trapezius. (a.k.a. transverse trapezius)

Attaches to:

  • Spinal processes of the 1st to 4th thoracic vertebrae.
  • Supraspinous ligament.
  • Medial side of the acromion of the scapula.

3. Lower trapezius. (a.k.a. inferior trapezius, ascending trapezius)

Attaches to:

  • The spinal processes of the 5th to 12th (last) thoracic vertebrae.
  • Supraspinous ligament.
  • Posterior crest of spine of the scapula.
  • Deltoid tubercle of spine of the scapula.

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Between the 6th cervical and 3rd thoracic vertebrae (the base of the nuchal ligament and start of the supraspinous ligament) the trapezius muscles are connected to the midline by a broad semi-elliptical aponeurosis, forming a tendinous ellipse between the shoulder blades.

Tendinous ellipse of connective tissue.

My comments.

The trapezius muscles - from the back of the head to mid-back, extending out to each shoulder.

A kite-shaped blanket of muscle that should be smooth and wrinkle-free, supporting the head and arms through a full range of movement.

The trapezius muscles attach to the base of the skull via a thin sheet of connective tissue (lamina) and there is a ellipse of connective tissue at the base of the neck/between the shoulder blades too.

Movement of the upper body should begin from the lower trapezii. Think extension and expansion from midline outwards.

The middle trapezii should spread wide allowing the arms to fully extend. Our upper limb includes the scapula.

The upper trapezii should be free of tensions, allowing the head to move through its full range of movement and alignment of the nuchal ligament.

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Pelvic Floor Muscles.

The "pelvic floor" are the muscles that span the pelvic canal. Also known as the pelvic diaphragm.

Left and right sides of the pelvic floor are a mirror image, the line of symmetry the body's midline.

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The pubic symphysis (where the linea alba and rectus abdominis muscles attach to the pelvis) is located on the midline of the anterior border of the pelvic canal.

To describe the pelvic floor in detail would be time-consuming - and frustrating. The anatomy is complicated with some controversy with regards to nomenclature, and is unimportant to this process. Think of the pelvic floor muscles as one unit of two halves.

My comments.

The pelvic floor muscles - a basket of muscles that should be tight and secure.

Activate your pelvic floor muscles and think of them at the root of all movement.

The solid Base for the the rest of the body.

Rectus Femoris.

The rectus femoris muscles at situated at the front of each thigh, extending from pelvis to tibia.

The rectus femoris is traditionally described as part of the quadriceps femoris muscle group, along with the 3 vasti muscles (the vastus lateralis, vastus intermedius and vastus medialis).  

The distal tendons of the 4 quadriceps muscles merge to form the common quadriceps tendon, which attaches to the patella (kneecap) and then continues as the patellar ligament to the tibial tuberosity of the tibia. i.e. the quadricep muscles share a common insertion but rectus femoris attaches to the pelvis, whilst the 3 vasti muscles attach to the femur. The rectus femoris is the only muscle of the quadriceps that crosses both the hip and knee joints.

. image text The pelvic attachments of the rectus femoris muscles are commonly described as "to the ilium of the pelvis via two heads - the straight head and the reflected head" but it is not that simple - variations in the pelvic attachments have been observed.

  • The tendon of the straight head attaches to the anterior inferior iliac spine.
  • The rectus femoris may also arise from the anterior superior iliac spine.
  • The tendon of the reflected head attaches in a groove above the superior rim of the acetabulum and the fibrous capsule of the hip joint. The reflected head may be absent.
  • A 3rd head may be present, attaching to the iliofemoral ligament deeply, and superficially to the gluteus minimus tendon as it attaches to femur.

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The heads of the rectus femoris merge into an aponeurosis (a tough, thin sheet of connective tissue), from which the muscle fibres arise as the aponeurosis continues distally on the anterior surface of the muscle.

The lower two-thirds of the posterior surface of the rectus femoris consists of a thick, broad aponeurosis that becomes narrowed into a flattened tendon attached to the patella.  This forms the superficial, central part of the common quadriceps tendon.

My comments.

The rectus femoris muscles - a strong pole down the front of the thigh when engaged along their full length. Positioning the leg to the pelvis and aligning the hip and knee joints.

Feel each muscle contract between it aponeuroses - think of pulling your kneecaps up and pushing down from your hip bone.

Gluteus Maximus.

Situated at the posterior of the pelvic region, the left and right gluteus maximus muscles are the largest skeletal muscles in the body.

The superficial muscle layer of the buttocks, covering and surrounded by a lot of complicated anatomy.

The gluteus maximus muscles attach to multiple structures, many more than the current standard description covers.

Attachments of the gluteus maximus:

  • The ilium of the pelvis (posterior to the posterior gluteal line {attaching to a narrow, semilunar area with a rough surface}, and the posterior superior iliac crest.
  • The sacrum (posterior inferior edge).
  • The coccyx (lateral sides of the posterior surface).
  • The aponeurotic fascia of the gluteus medius muscle.
  • The sacrotuberous ligament (posterior surface).
  • The tubero-iliac ligament (part of the long posterior {dorsal} sacroiliac ligament).
  • The thoracolumbar fascia. (Through its attachment to the raphe of the thoracolumbar fascia, the gluteus maximus is coupled to the ipsilateral multifidus muscle and to the contralateral latissimus dorsi muscle.)
  • The iliotibial tract. Three-quarters of the fibres form a superficial lamina (layer)which narrows and attaches between the two layers of the tensor fascia latae, forming part of the iliotibial tract. (a.k.a. iliotibial band.)
  • Gluteal tuberosity of the femur. Via an aponeurosis formed from the deeper muscle fibres. (The gluteus maximus attaches between the vastus lateralis and adductor magnus). .

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My comments.

The gluteus maximus muscles work in tandem with the rectus femoris muscles, stabilising the leg through a full range of movement.

The largest muscles of the body that position the leg to torso when fully engaged.

"Buns of steel" - Hands on buttocks. Feel these muscles contract and tighten.

The gluteus maximus muscles are superficial to, and surrounded by, a lot of anatomy prone to pain syndromes (caused by these main muscles not being adequately utilised?).


Based on my recovery from a life-time of pain, I believe learning to use these 5 (paired - left and right) main muscles movement to their full potential is the key to better physical health:

Base-Line Hypothesis of Human Health and Movement (part 1).

Base-Line Muscles.

Find your 'Base-Line' for better health.

Pelvic floor Base

Rectus abdominis Line

The position of the rest of the body is relative to your Base-Line. The core from where the rest of the body extends.

The linea alba is our primary guide for body alignment.

The Base-Line muscles should be strong and flexible, able to bend and twist at every level supporting the rest of the body though a full range of movement.

Our central pillar of strength.

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Think solid Base and a strong central Line. (see below for introduction to technique - 'breathing with your Base-Line').

Focusing on your Base-Line is the key to developing your conscious proprioception skills to increase the connection between body and mind.

- - -

Our Base-Line muscles are two of the '5 main muscles of movement' which, when fully utilised, provide the central framework for the body to achieve a full range of natural movement, dynamic alignment and balance.

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Connect Your Base-Line to Your Legs.

+ Gluteus maximus.

+ Rectus femoris.

It should be possible to move each leg through a full range of movement in a smooth and controlled manner, without effort or strain. This is possible when the gluteus maximus and rectus femoris muscles of each leg work in tandem, connected to Base-Line support.

Engagement of these leg muscles is about feeling them contract and strengthen.   Solid supports that correctly position the legs to the torso, aligning the hip and knee joints.

Aim for a balanced contraction of both muscles, left and right sides, in all positions.

Connect Your Base-Line to Your Upper Body.

+ Trapezius.

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  • Do you have any connection to your trapezius muscles?
  • Can you activate them from mid-back up? Pushing your shoulders up from under, not pulling them up from above.
  • Can you feel your arms extend out from midline? Your shoulders free to move and rotate?
  • Can you let your head relax forwards? Fully, without tension?

The whole of both trapezius muscles should be free to fully extend in all directions, without pain or tension, supporting the head and arms through a full range of movement.

The trapezius muscles align the nuchal and supraspinous ligaments when they are fully utilised.


Technique - Breathing with Your Base-Line.

▹Breathe in and up through your nostrils.

▹Breathe out through your mouth.

▹Engage your Base-Line muscles as you inhale.

∗ Begin with your Base pelvic floor muscles.

  → Take as many breaths as you need to feel your pelvic floor muscles engaging.

The solid base from where all movement should stem.

∗ Then focus on your mid-Line muscles.

  → As you breathe in and up through your nostrils, focus on each section of rectus abdominis muscles activating and extending in sequence, from your pelvis to your chest.

Think: Longer and stronger with every breath in.

Take as many breaths as you need to engage and elongate your Base-Line.

Be aware of when 'the wrong' areas of muscle activate.  When you feel this happening - relax, breathe and focus on your Base-Line muscles once more. ('wrong muscles' to be expanded on in later posts.)

Keep doing it!


Maintaining the body is not about doing specific exercises or reaching certain poses.

Work towards a full range of movement by focusing on these five main muscles, starting with your Base-Line.

Pelvic floor Base, rectus abdominis Line.

When these main muscles of movement are free to be fully utilised the rest 'falls into place' .

The body is strong and movement flows when we can achieve dynamic alignment and balance.

At least that's what I've found. I just need a few others to find out for themselves how lesswrong I am!

Part 3: Conscious Proprioception - Your Sense of Position, Movement & Balance.