Do you jump higher if you leave your off-hand free while you dunk?

After recording one of my athletes dunk attempts the other day I take the video home to break it down and analyze his movements when I noticed he would use a technique that I have been seeing a lot lately. Why are so many young players beginning to leave their off-hand free when dunking off of one foot? That night I ask my player, "Ive noticed you've been using one hand to dunk the ball lately. What made you start doing this"? His reply was simply, "it feels easier than going up with two".

Through 15 years of coaching I have always emphasized the arm swing to create force through the jump. Now this new technique of jumping has me studying, experimenting and debunking all previous perspectives of efficient jumping. Are we supposed to be creating energy through our core or maintaining the energy created through the ankles, knees, and hips?

The picture to the right is a snap of the middle of Tyson's jump. Looking at the dunk frame by frame I start to see what I was hypothesizing. His torso stays straight or moves much less than with arm swing (oppose to the slight bend you see with the arm swing) and neither arm crosses the center of his body, which means his core stays tight and stabilizes the jump. The one time I see his torso turn is when he cocks the ball back to slam it, which is normal (see slides at the bottom).

When we talk about transferring energy through movements like running and jumping we using our core to stabilize that transfer of energy. This is why if you have ever seen a novice runner that seems to rock side to side while running, they are usually the slower runner. "The core musculature connects the upper and lower extremities and act as a link between them during movement... when the core is weak, forces are not effectively transferred through the kinetic chain, resulting in inefficient movement and wasted energy from muscle elasticity (i.e. energy leakages) during sprinting, jumping, etc." 1. Sprinters are taught to train the core to resist the rotational torque created by the rapid moving of our limbs. So are most of the jump training being done today (including mine) the most effective way to train? About two months ago we began jump training and, of course, I am teaching him to synchronize his arm swing with his knee drive. As the weeks go on I see him trying out something different. This is when as a coach I step out of the way of learning. Allowing him to rehearse new motor patterns and naturally find the most efficient movement.

But then again, I study a ton of amazing trainers (PJF, SWISH, Max Schmarzo, Cory Schesinger, Tyler Ray... I can go on for days but quick shout out!) and I have seen the arm swing work. How do you explain the fact that LeBron has a great arm swing across his body and still at the age of 35 he jumps out of the gym? Well, not everyone is LeBron! He is very efficient at keeping his core tight and stabile while aggressively swinging his arms across his body. Every time you see LeBron post a workout on social media it is no coincidence that majority of his exercises are core or energy transfer exercises. So when you look close you will see a similarity in the torso movement (or lack there of) between my athlete Tyson and LeBron (swipe through the slides below). Not to compare the two jumps because obviously LeBron has many more reps at this and is a better jumper. But it does pose the question, does Tyson's body and mind decide to use this technique to compensate for not having a core as strong as LeBron's? If so, should we still be teaching our young players with undeveloped core to swing their arms when they jump? Personally I will be testing both strategies, but if a trainer or coach does decide to continue to train the arm swing, training to stabilize the core through rapid arm movements should be a main component of the core training.

Question: Do you jump higher if you dunk with your off-hand free while jumping off of one foot.

Answer: Maybe... I truly believe that there is a good possibility that allowing your off-hand to stay free can make your movement more efficient when jumping, but of course we need many more studies and experiments to be done for us to develop this theory further.

What do you think about this? If your'e an athlete, will you be switching up the way you jump to dunk? If you are a trainer, will you try out a different method of training? Let's get the conversation rolling so we can solve this theory!

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1. 'Developing the Core: Sport Performance Series'. 2014. Jeffrey M. Willardson, NSCA