Knee Line

When using your legs as clamps or wedges, keep your target inside the invisible triangle between your knees and groin.

In Jiu-Jitsu, few ideas are as deceptively simple as the knee line. You’ve probably heard the term thrown around when talking about guard passing or leg entanglements. But what exactly does it mean?

Let’s break it down conceptually.

🦵 What Is the Knee Line?

Imagine an invisible line connecting your two knees. That’s your knee line.

Now, add a third point: your groin. Now you’ve got an invisible triangle between your legs. That triangle defines the space where your opponent can be trapped and controlled. If their body (or the part you’re attacking) is inside that triangle, you can clamp onto them or wedge them in place effectively. If it’s outside, you can’t effectively clamp/wedge them with just your legs, and you’ll need an alternate way of holding them in place.

🔺 Why It Matters

The knee line is about using your legs as weapons of control, or preventing your opponent from doing the same. It shows up everywhere:

• Closed Guard: The guard only works if your opponent’s torso is inside that triangle. If they posture out and leave that space, you lose your clamp and must switch to an open guard.

• Guard Passing: To pass, you must clear the knee line. As long as your knee is caught inside your opponent’s triangle, you’re stuck. Once you free it, the pass can begin.

• Leg Entanglements: Controlling your opponent’s knee inside your triangle gives you access to the bend in their leg. Lose that knee, and the leg slips out like a stick between chopsticks.

⚙️ The Three-Joint Rule

Your legs (like your arms) move through three joints: hip, knee, and ankle. The more of these you control, the more dominant your position.

Control one joint (like an ankle), and you’ve just got a grip. Control two (ankle and knee), and you can immobilize. Control all three (hip, knee, and ankle), and you can submit.

🧠 Applying the Concept

Think of the knee line as a moving triangle. As you or your opponent shift, the triangle changes shape. To maintain control, keep the target inside that triangle. To escape, move your attacked limb (or body) outside of it.

It’s geometry in motion.

If you can feel that invisible triangle, you’ll understand why your leg entanglements, passes, and guards succeed… or fail.

Summary:

• The knee line is the imaginary line between your knees.

• Add your groin, and it becomes a control triangle.

• To control: keep your opponent inside that triangle.

• To escape: get your vulnerable body part outside it.

• This applies to guard passing, leg locks, and closed guard alike.