Nothing is more painful, frustrating, and sometimes, devastating, than injury. We all remember the great Roger Federer shedding tears after losing the 2009 Australian Open final, only to beat Andy Roddick at Wimbledon later in the year, prompting a similar reaction from the beloved American.
But neither episode was anything like what we saw from Alexander Zverev at the 2022 French Open. Those were cries of agony, not mere grief, fueled not only by the pain of his tearing ligaments, but even more so by the unrelenting frustration of being robbed of an opportunity to compete.
It was a tragedy, and I hope he recovers quickly.
It also gives us an opportunity, while this specific injury holds vivid in every player’s mind, to review the basics of fault tolerant movement in tennis.
So What Happened?
While moving to his right, Alexander Zverev hit a forehand. There are two ways to recover from the position he was in:
- Stutter step
He chose the former, but simply missed his final step.
His foot didn’t get sufficiently far away from his center before contacting the ground. Friction between the ground and the edge of his sole held the foot in place, while his body weight, still moving rightward, shifted far past his center of balance, causing his right ankle to buckle.
When the ankle buckles like this, the shoe’s sole acts as a lever to snap it; the taller the sole, the more force is applied.
Fault Tolerant Movement
From a fault tolerance standpoint, what happened to Alexander Zverev was a fault – a small mistake in execution. His foot caught on the ground before he wanted it to.
Similar to stroke production, movement must be fault tolerant. You won’t execute every step perfectly, the same way you won’t execute every shot perfectly. We need to train in a way such that these small movement faults don’t cause injury.
Athleticism = Force
Before we get into prevention strategies, it’s important to make something clear:
Alexander Zverev is one of the most coordinated athletes on the planet, and he snapped his ankle playing tennis. I’m sure he also understands everything that follows in this article. If you’re trying to perform at the absolute peak of human capacity, there’s going to be some risk, and if you’re 6’ 6’’ while doing so, even more.
Reaching for higher performance entails reaching for higher force production on court. The greater the forces involved in your tennis game, necessarily, the greater the injury risk, all else being equal.
Prevention #1 – Don’t Slide
Severe ankle injuries are due to foot planting. Even if your foot occasionally gets caught on the court, if you are attempting a stutter-step follow-through, rather than a slide, the resulting sprain is typically minor. You’ll probably fall, but your full weight won’t be driven through your planted foot and into your ankle, because the goal was never to fully load that foot in the first place.
Depending on your tennis goals, you may never need to slide. The position Alexander Zverev’s foot is in while being injured is actually an acceptable position for the foot during a stutter-step follow-through. In other words, if he were attempting to have his foot merely bounce off the ground at that location, rather than stop and slide, he would have been fine, and if he’d caught the edge of his shoe unexpectedly early, he would have just tripped and fell.
The stutter step follow-through is more fault tolerant than the slide. It allows a greater range of faults – small execution mistakes – without injury. The price, of course, is that it’s a less time-efficient way to recover, putting the player in a worse position defensively than a slide would.
In a stutter-step follow-through, instead of planting the foot and using sliding friction to dissipate your energy, you simply bounce off the arch of the foot as you continue on to your right. As you shift your weight back left and stop yourself, you never allow your feet to plant, and instead always allow them to bounce back off the ground when the force seems to demand it. Eventually, all of your rightward kinetic energy has been dissipated, and you press back to the center of the court.
This method requires an athletic understanding of how to properly load and deload the foot. If you’re clunking around on the court like you have cinder blocks on your feet, one false step, and you’re going to end up like Sasha Zverev.
Some players have a naturally springy step, but most don’t. Developing this ability will vastly improve both your agility and your safety on court.
Lower Soled Shoes
Another trade-off you can make, if you’re a habitual ankle roller, is using lower soled shoes. The cushioned sole of a tennis shoe helps protect the foot during heel strikes, but it also acts as a lever to snap the ankle during an ankle roll.
The more cushion your shoe has, the more aggressive you can be slamming that foot into the ground when you change direction, but also the more injurious a false step becomes. If your main problem is ankle rolling, try choosing a shoe that’s lower to the ground. This will give you a better sense of the ground as you move and will make false steps less damaging to the ankle.
Prevention #2 – Slide Wide and Low
A safe slide requires the final plant foot to be well outside the body’s center of mass. This ensures that the energy from the player’s momentum is pushing out through the inside of the foot, rather than over the top of the foot, causing an ankle roll.
When you slide wide, you will be more balanced: the wider your stance, the farther your body-weight is from tilting over either foot. Further, a wider final step increases the chance of contacting the ground with the inside of your foot first, which makes an ankle roll significantly less likely.
Sitting low while sliding further improves safety. It lowers your center of mass, decreasing any lever acting on your ankles if that center of mass moves slightly off your center of balance. It also increases the activation of your lower body musculature, allowing you to improvise better in the event of an emergency.
A wider, lower slide is more fault tolerant. The fact that you’re aiming for a wide stance means that, even if your foot catches a little early, it still likely won’t be close enough to your center to cause a severe injury. Even if your mistake is severe enough that your ankle does turn, the lower you are, the less leverage will be applied.
During your slide, even if you “catch an edge,” and your shoe regains traction with the ground before you’re ready, you probably won’t get hurt if you’re sufficiently wide, low, and balanced. You see this happen occasionally on the tour, and typically the player takes an awkward hop or two at the end of their slide, (or in more severe cases, falls) but is fine.
Not Trading Ankle Rolls for Groin Strains
A wide, balanced slide requires a significant amount of strength and flexibility. We aren’t trying to avoid ankle rolls, only to damage our knee cartilage and strain our groin muscles every time we’re on defense.
We’ll go into detail on tennis specific lower body conditioning at a later date. For now, we’ll mention the beneficial effects of the barbell back squat on slide ability. The barbell back squat is an efficient compound exercise that trains the strength, the low stance, and stretch reflex that’s employed when we slide.
Focus on opening your hips at the bottom, and feeling that nice, explosive stretch reflex out of the hole. You want to feel your leg muscles reach their full stretch, and then snap back to drive you up. This stretch reflex protects you when your muscles stretch during a slide. While you squat, ensure your weight is balanced over both feet, both front-to-back, and left-to-right, throughout the entire descent and ascent. Use less weight if you have to. Properly balanced reps will develop your ability to maintain balance under load, a massive benefit that will translate to your tennis.
Prevention #3 – Play Barefoot
Okay, obviously this is a bit of a joke, but not entirely.
When you play barefoot, your brain typically won’t let you get injured. You’ll take many, many extra steps to decelerate, and you’ll never even consider sliding. You’ll move quite gingerly, your brain acutely aware of how much force it has to dissipate on each change of direction. If you’ve never played barefoot before, play very lightly, and certainly don’t play barefoot while keeping score or competing. It’s merely an exploratory exercise.
Your body was built barefoot. When you don your tennis shoes and take to the court to compete, understand that you’re assuming some risk. Even an athletic freak like Alexander Zverev can take a quick misstep and snap his ankle.
With training, practice, and proper technique, this risk can be minimized. Train your strength and flexibility, slide low and wide, and use a barefoot-mimicking, stutter-step follow-through when possible, and you’ll develop a fault tolerant movement style that’ll keep you agile and healthy for the long run.