I agree with Shannon Elliott reference working on drawing your weapon while on your back and the awakwardness of this skill. A drill that I learned and teach today is the following: Assuming that you fell, were knocked down or tackled to the ground. While laying on your back , place your feet flat on the ground (this will have your knees bent) thrust your hips up, keeping your butt off the ground and access your weapon. Once you have access to your weapon drop your hips back down. Now you have the ability to engage your target from between your knees, if you need to. Raising your hips will help you clear any possible obstructions that you may encounter,ie, high grass,broken glass, anything that may cause you to slow your weapon draw. Also , practice this with your legs straight out and in different environments.