Kinetic Chains are groups of muscles that work together as a team. There are chains like this running all though our bodies.
If one link of the chain is tighter or shorter or weaker and you get disharmony in how they move your skeleton. Not pretty. Not comfortable, either.
There's a kinetic chain that I call The Magic Link. It’s the direct connection of our hips and shoulders, via our breath. It has a massive effect on our posture, and therefore on how much pain we feel in our day-to-day lives.
The thoracic diaphragm is a sheet of internal muscle that extends across the bottom of the rib cage. The diaphragm separates the thoracic cavity (heart, lungs & ribs) from the abdominal cavity and performs an important function in respiration. It’s your primary breathing muscle.
The diaphragm connects to the spine, in part, via its crura, or 'legs'. The right one arises from the upper three lumbar vertebrae, and the left, slightly shorter, from the upper two lumbar vertebrae. They blend with the anterior longitudinal ligament which traverses every vertebra in your spine.
Watch as the Magic Link reveals its mysteries!
The psoas and iliacus are usually called hip flexors but they do other jobs too. Yes, they bring your leg closer in towards your body (hip flexion) but they also, if short, can shear your ribcage forward, or flatten your lower back, or both. The psoas joins your thigh bone (femur) to your spine and inserts through every vertebra of your lumbar spine (lower back) and the lowest vertrebra of your thoracic spine.
Did you notice those muscles are linking to the spine?
They are very useful muscles: without them we couldn’t lift our legs against gravity or, for that matter, sit upright, because there wouldn’t be anything pulling our spine and legs together. We’d just flop back like ragdolls.
The trapezius muscle, which is named from its trapezium-like shape, runs between the neck, the anterior chain, the two shoulders, and the thoracic vertebra, T12. Its functions are to move the scapulae (shoulderblades) and support the arm.
The trapezius has three functional regions: the superior region (descending part), which supports the weight of the arm; the intermediate region (transverse part), which retracts the scapulae (draws them back towards your spine); and the inferior region (ascending part), which medially rotates and depresses the scapulae (turns the shoulderblades inwards and brings them down towards your tailbone).
Usually the upper traps are too tight and strong, and the intermediate area is too weak, leading to hunchitis. But I digress.
Did you notice that?
All three of those muscles insert into your spine, via some form of connective tissue, at your lowest thoracic vertebra, T12.
That means every time you tense your shoulders, you are pulling on your diaphragm, and also on your hip flexors!
Every time you hold your breath, you are tensing your hips and your shoulders, because they are all connected in the exact same place!
Understanding this link changed everything about my practice and allowed me to move out of my chronic (and excruciating) back pain.
Here's a really simple exercise to help you feel this link:
Sit (or, to allow those psoas muscles to relax more, lie) comfortably, and start breathing easily. Now, tense your shoulders. Notice what happens - you can touch your shoulders, then feel for your diaphragm, which is easiest to find right where the two sides of your ribcage meet at your upper belly, then touch your psoas muscles, which are easiest to feel just under the nub or your hipbones. They often feel like tendons, very hard. Now release.
Tense your hips. Follow the same process of observing. Now release.
Hold your breath. Notice what happens. Release.
It takes a bit of practice to be able to notice what the Magic Link is doing, and also to feel what happens if you are tensed up - but it's so worth it!
Knowing a bit about anatomy is useful for all of us, to help us be our most awesome selves.