Quadruped movement sets the stage for sound bipedal movement. That’s why you must first learn to crawl before you can walk. The Bear Crawl works the anterior chain or the frontside of your body. Think of it as a moving plank. The Crab Crawl works the posterior chain or backside of your body. Think of it as a moving bridge.
First position your hands under your shoulders & your knees under your hips. Then sync up the movement of the opposing arm & leg and mix between an inhale through the nose & exhale through the mouth every step.
You can perform both types of crawls from a high & low position. Mix between linear & lateral movement for best results. My favorite variation is the bear to crab roll which allows you to fluidly flow between both shapes for a 3-dimensional mobility & stability challenge. You can also play with arm & leg reaches to spice them up. One of my favorite starters or finishers is 5-10 minutes of continuous crawls, resting only as needed.