Remain Aligned beneath the Centre of the Torso When Retreating

Remain Aligned beneath the Centre of the Torso When Retreating

When retreating and sinking during partner practice（雙人練習中的後退與下沉）, the tailbone may release downward with a very slight inward adjustment（尾閭微收）. However, it should remain aligned beneath the centre of the torso（尾閭守中）. It should not swing behind you, shift sideways, or be forcibly pushed forward.

A better description is:

As you retreat, let the tailbone sink along the central axis while the pelvis follows the whole body backward.
後退時，尾閭沿中軸下沉，骨盆隨全身整體後移。

Important distinctions:

• Correct: the whole body retreats as one unit（全身整退）; the spine remains upright（立身中正）; the tailbone sinks and stays beneath the torso.

• Incorrect: the hips move backward first while the chest remains forward（突臀前俯）.

• Incorrect: forcefully squeezing the abdomen and buttocks to tuck the pelvis（夾臀收腹）.

• Incorrect: leaning backward and placing all the pressure in the heels（後仰壓跟）.

The slight tuck is not an independent action. It is a subtle adjustment within Song（鬆）, sinking（沉）, and maintaining central alignment（守中）. The lower abdomen may become gently supportive, but the kua and breathing must remain free.

When receiving your partner’s force, keep this relationship:

Head rises gently（頂頭懸） → spine lengthens（脊柱拔長） → tailbone sinks（尾閭下沉） → kua releases（鬆胯） → feet receive the force（勁落腳底）.

The tailbone remains “in the centre” in two senses:

1. Left–right centre（左右居中）: it does not shift unnecessarily to either side.

2. Front–back balance（前後平衡）: it remains beneath the spine without protruding backward or being forced too far forward.

But “staying in the centre” does not mean that the pelvis remains fixed in space. When you retreat, your entire centre of mass（重心）moves backward. The tailbone travels with the centre while maintaining its relationship to the spine and feet.

A good partner test is to ask your partner to apply slow, steady pressure. Retreat gradually and check whether:

• The shoulders remain relaxed.

• The chest does not lean backward.

• The buttocks do not protrude.

• The kua continue to fold and rotate.

• The pressure travels through the legs into the feet.

• You can stop, change direction or issue force at any moment.

If you cannot turn or step, the tuck is probably too strong. If the partner’s pressure collapses your lower back or pushes your hips behind your base, the tailbone has probably lost the centre.

The refined principle is:

The tailbone sinks but is not forced forward; the centre retreats but does not collapse; the body yields but does not lose Peng.
尾閭下沉而不強收，重心後移而不塌，身體走化而不失掤。