shift-weight

name	shift-weight
description	Atomic balance primitive that shifts the body's weight over one supporting foot with a small torso lean (and optional root nudge), so the other leg is free to lift, kick, or step. Use as the weight-transfer building block before any one-leg move. Mentions shift your weight, lean onto one leg, balance on one foot, transfer weight, weight on left/right leg.
category	posture
disable-model-invocation	true

shift-weight

Focused single-primitive of balance: move the center of mass over the support foot by leaning the torso toward that side. This is the transfer that frees the other leg. It is a focused slice of balance-and-posture (which carries the full posture checklist); for the actual lift/kick use move-leg.

Joints: Spine,Chest lean on Z (POSITIVE Z = lean toward its LEFT, NEGATIVE = toward its right), optionally a small root.x nudge toward the support foot (world +X = its right). Keep the support {Side}Foot flat at rest [90,0,0] (see plant-foot).

Recipes

• Weight onto the LEFT foot: Spine:[0,0,10],Chest:[0,0,8] (optional root.x:-0.05).
• Weight onto the RIGHT foot: Spine:[0,0,-10],Chest:[0,0,-8] (optional root.x:0.05).

Worked Actions

• "shift your weight onto your left leg" → {"durationMs":500,"pose":{"Spine":[0,0,10],"Chest":[0,0,8]},"say":"Shifting over."}
• "balance on your right foot" → shift right, then lift the left knee (move-leg): {"durationMs":800,"pose":{"Spine":[0,0,-10],"Chest":[0,0,-8],"LeftUpLeg":[90,0,0],"LeftLeg":[90,0,0]},"say":"Balancing."}

Limits

Lateral lean stays within ~±12 for a weight shift (bigger is a move-torso lean). Always keep the support foot grounded.