The Spinoff Reviews New Zealand #56: Lisa Prager’s sledgehammer technique

We review the entire country and culture of New Zealand, one thing at a time. Today, Madeleine Chapman winces while watching cycleway protester Lisa Prager swing a hammer.

As Lisa Prager diligently swung her sledgehammer over and over again in an attempt to break a concrete block, my back started to hurt. She was side on, with no hand movement, and swinging low. She was doing everything to guarantee that any force she wanted going into that concrete block would instead go straight into her wrists and spine, leaving her whole body very sore tomorrow. I watched her and I wept. The only thing worse than seeing someone suffer a self-sustained injury is seeing someone perform a task poorly. With sledgehammer in hand, Lisa Prager was doing both.

Camped out on the corner of Richmond Road and Surrey Crescent, Prager is putting into action her promise to stop Auckland Council from making roads safer for pedestrians and cyclists. Her target? A kerb recently constructed on the side of the road, apparently to create a safe cycleway through Grey Lynn. Prager said no, that won’t do, and set about literally dismantling it with the help of a sledgehammer and crowbar.

But how did she really do? David Farrier (posting Sophie Musgrove’s video) thought she was very good. Farrier has been right about many things but this isn’t one of them. Lisa Prager is terrible with a sledgehammer. I’m no expert lumberjack, but I’ve swung enough sledges in my life to know when it’s being done wrong. My dad taught me how to chop wood when I was ten. It took me a while to get the technique right but it’s come in handy a lot since then, especially last year when I used sledgehammer swings as training for throwing the javelin.

So let’s break down Prager’s technique and see where she’s gone wrong.

Step 1: stance

Prager stands perpendicular to the concrete block she wants to smash. This is already lessening any force she hopes to generate. Ideally, you want to be standing square in front of your target, or facing the target with your weak foot forward. Granted, the ground is uneven but standing unevenly sideways is much worse than standing unevenly in front. She’s not off to a promising start.

Step 2: grip

This is perhaps Prager’s biggest technical error. While her left hand is well placed at the bottom of the handle, her right hand is far too low to be generating any sort of useful power. When swinging a tool such as a sledge, your strong hand should begin right up the top of the handle, basically touching the metal head. This allows for more control as you swing and encourages a higher back swing. A higher swing equals a longer arc equals more downward power generated. Which brings us to…

Step 3: backswing

Oh boy. This is bad. At the peak of her backswing, Prager is hunched forward. Say a prayer for her back. To get the most force bearing down on her enemy, the concrete block, Prager should be as tall as possible with a straight back and nearly straight legs, ready to begin a natural downward motion and letting the weight of the sledge do most of the work. Look at those angles that I masterfully drew and try figure out which one would be more effective in transferring energy from Prager to concrete. She’s not in a good place but there’s no going back once your downward swing begins.

Step 4: contact

A few things wrong here. The first is the bent arm. Bent arms and hunched back means Prager has relied solely on her own strength to generate power. If humans had the arm strength to break concrete, we wouldn’t need sledgehammers. Making contact with bent arms means a) Prager is standing too close to her target, and b) she has approximately no power in her swing. Sadly, of the little force she’s managed to generate with her biceps, most of it is about to be absorbed by her right hand. Remember when I said the right hand should begin at the top of the handle? Well it’s supposed to end at the bottom to allow for the longest downward arc and to distance them from the impact. What Prager’s done is plant her right hand in the middle and leave it there. That’s too close to the point of contact and a lot of the shock from metal colliding with concrete will be felt in her wrist. Let’s put up another prayer for Prager’s skeletal system.

Had she used her implement correctly, Prager should have been able to remove a concrete block every few minutes. But she didn’t, and that’s why the four swings shown in the video resulted in a puff of dust and nothing more, not unlike a concrete fart.

After doing everything possible to reduce power in her swing, Prager is left with just the weight of the sledge as force. She would’ve been just as effective holding a shot put above the concrete block and letting it drop.

I feel bad that Prager will wake up tomorrow feeling like her back has been torn in two but at the same time it’s a relief knowing that had she been given all the time in the world to break up that kerb, she’d still be there two weeks from now, valiantly patting the concrete with a 5kg metal sledge.

Instead, Prager has been arrested, supposedly for damaging public property, though the only damage I witnessed was to her body and to my eyes.

Verdict: Good sledging can break concrete, bad sledging can break your back.

Good or bad: Bad


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