When climbing makes its Olympic debut at these Games the spotlight will be on a field including Great Britain’s Shauna Coxsey. Elite climbers like Coxsey perfectly coordinate their movements, swinging their hips and using explosive power in their legs and arms to push downwards and launch towards their target hold, before catching it and controlling the swing.
In the modern, parkour-like climbing style, athletes paradoxically move like our prehistoric tree-dwelling ancestors, making gibbon-like leaps between holds. Dynamic jumps – called “dynos” – will almost certainly be in the route-setters’ playbooks in Tokyo. Conveniently, these urban-inspired acrobatic moves have also increased the sport’s spectator appeal.
So how do Coxsey and co do it? A climber’s centre of mass lies around the hips, and it’s in shifting this ballast that momentum is generated. Think of a weight at the end of a pendulum.
What goes up, must come down. The optimum moment for grabbing the target hold is just before the so-called deadpoint; the point of inertia at the apex of the climber’s leap, just before gravity sets in and starts to pull them downwards. You’ve probably felt this moment of “weightlessness” on a playground swing at either end of its arc.
It helps to get to grips with the physics of climbing movement. If momentum is generated, it must be absorbed once the climber catches the hold – otherwise they’ll fly off or slam into the wall. If you jump for a rung on the monkey bars, you’ll notice that your body will follow the trajectory of your hips. If you don’t control your body in any way, you’ll end up flying horizontally, peeling off the bar and landing flat on your back. This is where “collision fraction” – or absorbing force – is essential.
To control their movement, climbers tense their shoulders and pull up with their arms to counteract any force pulling them away from the wall. They also use their flexible spine as a damping mechanism to absorb energy by arching their back and bending their legs behind them to form the curved shape of a scorpion’s tail. This concertina-like articulation of the spine decelerates the swing and enables the climber to control the direction of their hips as they aim their feet back towards the wall.
In this graphic, Coxsey pushes down on both legs before catching the hold with both hands, letting her legs swing out and up behind her as she “scorpions” her back to control the swing and bring her feet smoothly back in. No flailing, optimum timing and minimal energy loss – she’s ready for the next move.
Look out for lots of complex versions of dynoing in Tokyo: run-and-jumps (a self-explanatory parkour special); 1-2 dynos (jumping and catching one hold then swinging up to another in one fell swoop) and paddle dynos (when climbers leap and rapidly bounce their hands along multiple holds, all rebound and elasticity, without using their feet).