Education · Upper arms

Elbow flexion & forearm rotation

Target Biceps  ·  Equipment Body weight  ·  Level Beginner  ·  Reps 4

Elbow flexion & forearm rotation is a beginner-level education movement targeting the biceps, written in Posecode, a small open-source language that LLMs like ChatGPT, Claude, and Gemini can write to describe human movement as text. Every joint angle below is hard-clamped to a safe range of motion.

How to do it

1. Flex & supinate2.5s · ease-in-out Bend the elbows and turn the palms up: flexion with supination
2. Extend & pronate2.5s · ease-in-out Straighten and turn the palms down: extension with pronation

The .posecode source

This is the exact text an LLM writes to produce the animation above: phases and joint angles, not 3D transforms.

posecode stretch "Elbow flexion & forearm rotation (ROM demo)"
  rig humanoid
  pose start = standing

  step "Flex & supinate" 2.5s ease-in-out:
    elbows: flex 140
    elbows: supinate 80
    cue "Bend the elbows and turn the palms up: flexion with supination"

  step "Extend & pronate" 2.5s ease-in-out:
    elbows: flex 10
    elbows: pronate 80
    cue "Straighten and turn the palms down: extension with pronation"

  repeat 4

More education movements