Knee on stomach: okay. Knee on face/ears/groin: not so good. Protective Gear is a must for anyone who wants to avoid injury to more sensitive parts of the body. Whether during rolling or more intense striking, protective gear will help keep you on the mat and out of the hospital. We have a wide selection of protective BJJ and MMA gear: groin protectors, mouth guards, knee pads, knee braces, headgear and more.