russian-twist

name	russian-twist
description	Performs seated Russian twists on the floor, leaning back with feet up and rotating the torso side to side with the hands together. Use when the command mentions Russian twist, russian twists, seated twist, or oblique twists.
category	exercise
disable-model-invocation	true
subskills	["move-torso","move-arm","balance-and-posture"]

russian-twist

Sit on the floor, lean back into a V with the shins up, clasp the hands in front, and rotate the torso left and right. Uses posture:sitFloor so the engine seats the body (don't set root.y).

How

• Seat & lean back: posture:"sitFloor", knees up (*UpLeg:[80,0,0],*Leg:[70,0,0]), torso reclined (Spine:[-20,..,0]).
• Hands together in front (*UpperArm:[100,0,±10], forearms folded LeftForearm:[0,0,-40],RightForearm:[0,0,40]).
• Twist: alternate Spine Y +30 ↔ -30 (with Chest following). Loop.

Example

• "do russian twists" -> {"durationMs":2600,"say":"Twist, twist.","posture":"sitFloor","sequence":{"loop":true,"frames":[{"t":0,"pose":{"Spine":[-20,30,0],"Chest":[-5,20,0],"LeftUpLeg":[80,0,0],"RightUpLeg":[80,0,0],"LeftLeg":[70,0,0],"RightLeg":[70,0,0],"LeftUpperArm":[100,0,10],"RightUpperArm":[100,0,-10],"LeftForearm":[0,0,-40],"RightForearm":[0,0,40]}},{"t":0.5,"pose":{"Spine":[-20,-30,0],"Chest":[-5,-20,0]}},{"t":1,"pose":{"Spine":[-20,30,0],"Chest":[-5,20,0]}}]}}