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Frames and Wedges

Dec 23, 2024 martial-artsphysicscraft

Brazilian Jiu-Jitsu allows smaller practitioners to overcome larger opponents through mechanical advantage. Two principles make this possible: frames and wedges.

Frames are structural supports that rely on bone alignment rather than muscular effort. A frame distributes your opponent’s weight across your skeleton, letting structure do the work. The classic example: forearm across the neck, elbow tight to the hip, forming a triangle. Even a strong opponent can’t collapse a properly aligned frame because they’re fighting geometry.

Wedges create or block space. A blocking wedge stops movement — knee across the hip prevents your opponent from closing distance. A prying wedge opens space — elbow inside the knee creates room to escape.


The geometry matters. Triangles are the strongest shape for distribution of force. The frame formed by knee-to-elbow-to-hip creates stability that a straight arm never could. This is why jiu-jitsu positions emphasize keeping limbs connected — isolated limbs can be attacked, connected structures resist.

Frames must also match the angle of force. A frame only works if it’s perpendicular to the pressure. This requires constant adjustment as position changes. The frame that protected you a moment ago becomes useless when your opponent shifts angle.


The principle appears throughout physical disciplines. Architecture uses the same structural concepts — arches distribute load, buttresses redirect force. The body follows the same physics.

Working smarter means understanding mechanics. Strength fades with fatigue and age. Mechanical advantage doesn’t. A 60-year-old with good frames can defend against a 25-year-old athlete because bones don’t get tired the way muscles do.

The training implication: prioritize alignment over effort. If you’re muscling through a position, something is geometrically wrong. Find the frame, find the wedge, and let structure do the work.

Related: [[invisible-jiu-jitsu]], [[sharpening]]