Marcelo implores his students to recognize two very common situations that could potentially lead to serious injury when training on the feet. Whenever your opponent is behind you, or beside you, take caution over the positioning of your legs. Don't let your opponent straddle over top of your knees and possibly fall or hang their weight onto them. If your opponent gets to this position, either sit-out and drop your hips as if resting on a stool, or quickly spin around and face them with a Sprawl. Sometimes you will end up in this position after failing to throw your opponent with Uchi-Mata or Harai-Goshi. Immediately, make an adjustment in the case that your partner doesn't know to protect your body. Conversely, if you are behind or beside your opponent, don't carelessly jump for their back or pull guard against the side of their legs. Lastly, Marcelo speaks on the catastrophic damage that can happen when two students impose a Burial/Crackdown exchange. If your opponent's head is against your hip or under your arm, you cannot fall and force their face towards the mat using your weight. Though sometimes taught as a legitimate fighting technique, the "Burial" (or Enterrada, a.k.a DDT, Hikikomi-Gaeshi, et al.) is a dangerous maneuver that can result in paralysis or even death, particularly when on a hard surface. If getting taken down, don't force your opponent's head under your fall. Likewise, if trying to take down your opponent, do not opt for the "Head-Outside" Single or "Crackdown" technique. Though effective, it is not worth the risk if your opponent accidentally or advertently attempts a drop or spike. With those cautions in mind, Marcelo has his students work specific training on the feet; groups work one minute standing and two mintues on the ground, rotating in against all possible pairs before taking a round off.