Pilates – Stabilising your shoulder blades (scapulae)
In Pilates, there are five basic principles to bear in mind and maintain in order to perform all the exercises effectively. One of these five principles is to ensure stability of the shoulder blades [or scapulae (singular: “scapula”) in medical terms]. To understand why this is important, we should first understand the anatomy of these specific bones.
The shoulder blades are a pair of flat bones roughly triangular in shape, located on the right and left sides of the body’s upper back. They are not linked directly to the spine or ribcage. Their only attachment to the mainframe of the skeleton (spine and ribcage) is through the collarbone (“clavicle”), which is in turn fixed to the breastbone (“sternum”).
Together with the upper arm bone (“humerus”), the scapula and clavicle make up the shoulder. This is one of the most moveable joints in the human body. The scapula, in particular, is highly mobile and acts as a “floating platform off which the arm is able to work”.[1] With great mobility however, also comes great instability, making the shoulder area prone to strain and injury.
Without a fixed “anchor” on the skeletal mainframe, the only way to stabilize the scapula is to engage the many muscles surrounding and attaching this bone to the rest of the shoulder area, the chest, neck, arm and back. It will reduce strain at your neck and core, minimizing the chances of injury. This is what is meant by scapula stabilisation in Pilates exercises.
Muscles attached to the scapula:
1. Rotator Cuff (S.I.T.S.)
- Supraspinatus
- Infraspinatus
- Teres minor
- Subscapularis
2. Teres Major
3. Rhomboid Major
4. Rhomboid Minor
5. Trapezius
6. Latissimus Dorsi
7. Serratus Anterior
8. Deltoid
9. Triceps Brachii
10. Biceps Brachii
11. Coracobrachialis
12. Pectoralis Minor
13. Levator Scapulae
14. Omohyoid
“Feeling” your scapulae – isolating the various scapulae movements
Key movements of the shoulder blades are:
- Elevation (shoulders rising towards ears)
- Depression (drawing down the shoulders, “lengthening” the neck)
- Protraction (drawing scapulae wider apart and forward, away from midline of spine)
- Retraction (squeezing scapulae together and backward)
Stabilising the scapulae means engaging the muscles around the shoulder blades to ensure that they do not flare or flop freely whenever you raise or lower your arms in the exercises, providing an extremely stable platform (firm joint) for arm movements.
For a list of basic exercises that allow you to feel or practise these key movements, check out Merrithew.com: http://www.merrithew.com/stottpilates/warmup/en/principles/shoulder-stability
Key muscles stabilising the scapulae
There are four primary muscles that stabilise the scapula against the chest wall. These primary stabilising muscles “fix” the platform so that the shoulder muscles attached to it can work efficiently and effectively to move your arm. They are:
- Trapezius (middle and lower)
- Rhomboid major
- Rhomboid minor
- Serratus Anterior
The middle trapezius and the rhomboid muscles retract the scapula, the lower trapezius depresses the scapula, while the serratus anterior holds the scapula’s medial border tight to the thorax.
If these muscles are weak and not working well, a flaring or winging of the shoulder blades can be observed. It will also cause the upper trapezius and neck muscles to overwork, creating “knots” and tension in them.
Sources for this section:
http://www.myyogaonline.com/about-yoga/yoga-anatomy/addressing-our-scapular-stabilizers
http://www.apemedical.com.au/useruploads/files/scapula_stabilisation_opt.pdf
Muscle actions in scapula movements
The blog B2C fitness (http://b2cfitness.com/cpt_blog/kinesiology-of-the-shoulder-and-scapula/) provides a detailed description of the various muscles and muscular actions involved in the scapula’s key movements. An extract is provided below.
Scapular Protraction
- Prime Mover: Serratus anterior
- Synergist: Pectoralis minor
- Antagonist: Mid traps, rhomboids
- Neutralizers: Upper and lower trapezius muscle acts to prevent downward rotation, and the lower trapezius muscles act to prevent elevation, and downward rotation.
- Stabilizers: Serratus anterior, rhomboids, levator scapulae
Scapular Retraction
- Prime Mover: Middle trapezius
- Synergist: Rhomboids
- Antagonist: Serratus anterior, pectoralis minor
- Neutralizers: Upper and lower trapezius muscle acts to prevent ancillary motion in the frontal plane (elevation and depression).
- Stabilizers: Serratus anterior, rhomboids, levator scapulae
Scapular Elevation
- Prime Mover: Upper trapezius
- Synergist: Levator scapulae, rhomboids
- Antagonists: Lower trapezius, pectoralis minor
- Neutralizers: The serratus anterior and rhomboids must carefully balance upward and downward rotation to prevent excessive motion in either direction caused by the prime mover and synergists.
- Stabilizers: Serratus anterior, rhomboids, levator scapulae
Scapular Depression
- Prime Mover: Lower trapezius
- Synergist: Pectoralis minor
- Antagonists: Upper trapezius, levator scapulae, rhomboids
- Neutralizers: The lower traps and stabilizers of the scapulae neutralize the anterior tipping force created by the pectoralis minor.
- Stabilizers: Serratus anterior, rhomboids, levator scapulae
Source: http://b2cfitness.com/cpt_blog/kinesiology-of-the-shoulder-and-scapula/
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Laurel