When the Arm Rises but the Shoulder Sinks: Biomechanics of White Crane Spreads Wings

When the Arm Rises but the Shoulder Sinks: Biomechanics of White Crane Spreads Wings

When the Arm Rises but the Shoulder Sinks: Biomechanics of White Crane Spreads Wings 

This is a very good and very precise Tai Chi question, and it touches the real meaning of

「沉肩垂肘」 being a functional principle, not a frozen shape.

I’ll answer it clearly from Tai Chi principle, biomechanics, and physiology, and then give you a clean conclusion you can use in an article.

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1. First, clarify the two “parts” of the shoulder

Anatomically and functionally, what practitioners call “the shoulder” actually includes two different systems:

(A) Shoulder–arm unit

• Glenohumeral joint

• Where the upper arm (humerus) connects to the shoulder

• Main function: positioning and expressing force through the arm

(B) Shoulder–torso unit

• Scapula (shoulder blade) + clavicle + rib cage

• Main function: transmitting force between torso and arm, and stabilizing structure

These two must not be confused—many misunderstandings come from mixing them.

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2. What 「沉肩垂肘」 really means

In Tai Chi, 沉肩 (sink the shoulders) does NOT mean:

“Never raise anything, ever.”

What it does mean is:

The scapula must remain sunk, wide, and connected to the torso,

so that force can pass from the root → waist → torso → arm without interruption.

So the rule applies primarily to the scapular–torso connection, not to the arm’s expressive movement.

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3. Why in pushing (e.g. Brush Knee) both parts “drop”

In movements like Brush Knee and Twist Step:

• Power is issued forward

• Force path is linear

• Structure must be maximally unified

Therefore:

• Scapula sinks and spreads

• Upper arm stays heavy and dropped

• Elbow sinks

• No local lifting

This ensures:

• No shoulder break

• No local arm force

• Maximum whole-body transmission

👉 In this case, both parts appear to “drop”, but the key is still the scapula.

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4. Why in White Crane you may raise the arm-side shoulder

In White Crane Spreads Wings (白鶴亮翅):

• The movement is rotational and circular (圓勁)

• One arm opens upward and outward

• The body is turning, not pushing straight

Here is the crucial distinction:

✔ What can rise

• The upper arm (and the humerus-side “shoulder appearance”)

• This is a result of arm opening, not scapular lifting

✖ What must NOT rise

• The scapula

• The connection to the torso must stay sunk and stable

In correct practice:

• The arm “floats”

• The scapula stays heavy, wrapped, and connected

• The chest does not pop up

• The shoulder does not shrug

This is why experienced teachers say:

「肩不動，臂自起」

The shoulder does not lift; the arm rises by itself.

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5. Biomechanics & physiology explanation

From a scientific perspective:

Good Tai Chi mechanics

• Scapula: downward rotation + posterior tilt

• Upper arm: can abduct or elevate

• Trapezius (upper): relaxed

• Serratus anterior & lower trapezius: active but not tense

Bad mechanics (common mistake)

• Scapula elevates

• Upper trapezius tightens

• Neck stiffens

• Force transmission breaks

👉 Tai Chi’s “relaxation” is dynamic control, not collapse or stiffness.

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6. So… who is correct?

❌ “Both shoulder parts must never be raised”

• Overly rigid

• Treats Tai Chi as static shapes

• Limits circular and spiral power

❌ “It doesn’t matter which part lifts”

• Breaks structure

• Causes shoulder tension

• Loses root connection

✅ Correct Tai Chi answer

The scapula must always remain sunk and connected to the torso;

the upper arm side may rise when required by circular movement,

as long as structure and connection are preserved.

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7. One sentence you can quote in your article

In Tai Chi, “sinking the shoulders” refers to maintaining a sunk and connected scapula, not freezing the arm. In circular movements such as White Crane Spreads Wings, the arm may rise while the scapula remains stable, allowing round force to flow without breaking the body’s integrated structure.