Keep your elbows close to your knees.
The elbow-knee connection is a specific application of limb coiling, a mental model that tells us to keep our limbs tucked close to our core. We tuck our limbs to prevent our opponent from using them as levers.
Establishing an elbow-knee connection is important because it creates a kinetic chain that prevents your opponent from accessing your belly. If your opponent can’t access your belly, it’s much harder for him/her to sweep, complete passes, or stabilize dominant positions.
An important note: you don’t want your elbow to line up exactly with your knee. If you make your elbow and knee actually touch, you’ll find it weakens your posture, which is something you don’t want. In reality, your elbow should be resting on the thigh slightly above the knee. This means the name “elbow-knee connection” is not entirely accurate, but it’s easier to remember than “elbow-thigh-slightly-above-the-knee” connection.
Applications for defense
The elbow-knee connection is especially important for preventing guard passes. In order to effectively pass your guard, your opponent must separate your arms from your legs. Ultimately, that’s what your opponent is doing when passing, establishing knee on belly, or taking mount.
Keeping your elbows and knees tucked closely together makes it much harder for your opponent to cut your body along the torso, which makes passing much more difficult.
Applications for offense
The elbow-knee connection is also useful when you are on the offensive. When you are standing in your opponent’s guard, try to keep your elbows and knees close together. This makes it much harder for your opponent to separate your leg and establish a dominant De La Riva hook or similar guard.