The battle for elbows: of the strongest positions that the human can hold is your held to your hip. This creates a very strong structure that an opponent will find extremely difficult to dislodge. The further your elbow drifts away from your hip – the weaker your arm becomes overall. A big part of grappling then, is the battle to create conditions where your arms are in a strong position close to your hips whilst your opponents elbows are in a weak position extended away from his hips. If you can reliably create this circumstance, you'll have a very considerable physical over your opponent. hooks are one great way to make this happen, as you can see here as works hard to pull an opponents elbow out and away from his hips to create openings for his famous game. Always look for opportunities to get an opponents arm extended while keeping your own retracted – you'll feel strong to your opponent and be in a great position to attack!