There was nothing he could do.
Writhing on the court in circles, Jayson Tatum clutched his lower left leg. He begged for a timeout. He buried his head in his hands before a Boston Celtics staffer rushed over and hid his face behind a towel. Tatum shook his head, he thumped it lightly on the floor.
For the six-time All-Star, a new reality had already started to set in.
“I remember grabbing my calf and I knew – I knew right away what had just happened,” Tatum told USA TODAY Sports recently. “My body went into shock, and I was squirming on the ground and all these things went through my mind. It was just like, ‘No way. No way did this just happen to me.’ ”
There was a time when Achilles tendon ruptures were considered career-ending injuries in the NBA. Modern medicine has made reparative surgery and its recovery more tolerable, but – because the injury robs players of entire seasons, the rehab is intensely grueling and slow-motion replays often reveal the exact moment when the tendon snaps – it remains the most devastating injury in the NBA.
Most concerning for the league is that ruptures are surging.
There have been 63 known Achilles tendon ruptures in the 55 NBA seasons since 1970, excluding the one that began two weeks ago. Yet, 29 of those ruptures – or 46% – have occurred over the most recent 13 seasons, at a rate of 2.23 ruptures per season.
Those data are skewed by last season’s record-high seven ruptures, but they nonetheless represent a significant increase over the previous 42 seasons, which yielded a rupture rate of 0.81 per season.
So what, exactly, is causing this spike?
USA TODAY Sports interviewed Tatum and nearly a dozen doctors, surgeons, epidemiologists and performance coaches, seeking to pinpoint factors driving the surge, and – most crucially – what can be done to prevent them.
According to experts, ruptures are multi-factorial and case dependent, though three potential causes for the increase predominated: the unprecedented explosion of youth basketball, insufficient time to heal from precursory lower leg injuries and the ubiquity of the false step, a rarely-discussed but widely used on-court maneuver.
“Trust me, I’ve asked a thousand questions to a thousand different people,” Tatum continued. “ ‘What could I have done to prevent this? What more could I have done?’
“My body felt great. It’s just kind of tough with this injury. They haven’t really been able to figure out why it happens to certain people.”
What is the Achilles tendon?
The Achilles tendon is a collection of fibrous cords that entwine to connect calf muscles to the heel bone. Think of it as a mop whose strands are tightly wrung.
The largest and thickest tendon in the body, the Achilles is made of collagen and elastin, a pair of proteins. Collagen is structural and provides strength for skin, muscles, ligaments, tendons and bones. Elastin, as the name implies, supplies elasticity and stretchiness.
Together, the proteins make the Achilles the strongest tendon in the body, one capable of incredible power and explosive propulsion.
Yet, the biomechanic traits that make the Achilles such a powerful structure also make it prone to injury, particularly near the middle of the tendon, where it is thinnest, often subject to the most tension and receives poorest blood flow.
Over time, the fibers twist and grind on each other, especially during intense athletic competition, when the cords are subject to repetitive microdamage or microtears. If not given time to heal and recover, the tendon’s health could be compromised, which may eventually lead to ruptures.
For NBA players, a rupture often becomes the worst-case scenario; studies have shown that, by and large, players who do return from the grueling rehab often aren’t quite the same, impacting future earnings. Teams, meanwhile, are forced to scramble and adjust.
“The level of concern is extraordinarily high when we’ve got an injury that causes a player to miss an entire season,” NBA senior vice president of player health Drew Galbraith told USA TODAY Sports. “It’s massive for those teams, particularly, when there are star players involved. We’re taking it very seriously.”
Over the summer, the NBA convened a panel of more than 30 experts from across the globe, giving them the platform to share their intel, but one aspect puzzled doctors, however: the ages of players suffering ruptures. Previously, the injury was thought to be exclusive to older players. Yet, ruptures have occurred from players aged 21 to 35.
In fact, the average age of players sustaining the injury is 27 – hardly that of an athlete in decline – and skewing younger. A 2013 study found the average age of players suffering an Achilles rupture to be 29.7 years old.
Youth sports give rise to ‘unhealthy tendons’
Amateur Athletic Union (AAU) basketball exploded in the late 2000s and early 2010s when it became a college basketball feeder system. A recent study surveyed a group of 590 active NBA players ahead of the 2023-24 season and found that a staggering 84.7% had played AAU basketball.
That added wear and tear, however, may be producing a cumulative effect on the lower legs of players entering the NBA. Through pre-draft screening and ultrasound imaging on joints and tendons, team physicians, in recent seasons, have encountered players entering the NBA already exhibiting signs of what could be clinically described as unhealthy tendons.
This spike of Achilles ruptures appears to coincide with the explosion of AAU hoops; the players profiting from that growth are now the stars of the NBA.
Indeed, Tatum (St. Louis Eagles), Tyrese Haliburton (Wisconsin Flight) and Damian Lillard (Oakland Rebels) – the three stars who suffered ruptures in the postseason – each played AAU hoops as teens.
“Think about the lifetime accumulation on these tendons,” Dr. Claire D. Eliasberg, an orthopedic surgeon with the Hospital for Special Surgery, told USA TODAY Sports. “With this early, early sports specialization, which has changed in recent years, by the time these athletes are in their late 20s and 30s, it’s almost like they’ve played entire seasons before they even enter the pros.”
It’s essential to note that youth basketball participation is merely one variable, one that’s not a definitive or conclusive precursor to injury; there are far more AAU alumni in the NBA who have never ruptured their Achilles than there are who have.
What is the false step?
The false step is a common movement athletes make – most often subconsciously – to generate explosive speed. It occurs when a player takes a quick step backward that shifts weight and momentum to the trail foot before launching forward.
The step creates powerful propulsion, but it can also inflict massive strain on the Achilles tendon. This is most notable when the trail foot extends far behind the athlete’s center of mass, often leading to a straightened knee and acutely dorsiflexed ankle. This, in effect, loads the Achilles like a spring.
If the player’s heel makes contact with the floor, the results can be devastating. Additionally, there can often be rotational forces that twist the tendon, putting further stress on it.
Also known as the negative step or rock step, the false step is the mechanism that overwhelmingly triggers Achilles tendon ruptures in basketball.
Film review of each of the seven ruptures from the 2024-25 season showed that each occurred after the player engaged in a clear false step.
In fact, the false step is also responsible for many of the ruptures observed in the NFL.
Adam Petway, an assistant professor and director of biomechanics for University of Louisville, has published several papers on Achilles ruptures in the NBA. Petway has served on the strength and conditioning staffs of the Washington Wizards and Philadelphia 76ers, and his most recent paper, published in March, examined minor and moderate lower leg injuries and their effect on Achilles ruptures.
Petway found that two injuries in particular, calf strains and plantar fasciitis, could be precursors to Achilles ruptures, especially when players returned to the floor quicker from those ailments than the general NBA population did.
“Our hypothesis is that there’s probably some sort of degradation or microdamage to the Achilles tendon prior to rupture, and that false step mechanism or negative step – whatever you want to call it – is the straw that broke the camel’s back, so to speak,” Petway told USA TODAY Sports.
The obvious question then becomes: why don’t teams coach the technique out of their players? The answer is that’s close to impossible.
The NBA studied its frequency, determining that it occurs around 90 times per game – a rough approximation totaling 118,800 false steps taken last season. Accounting for practices and warmups, this number is presumably far larger.
And, since, there were seven Achilles tears last season that came out of the false step, that puts the incidence of rupture from the mechanism at a miniscule 0.000059% – if not lower.
But it’s even more complicated than that.
The men’s high school basketball coach at Imagine Schools in North Port, Florida, Taft is also a performance coach who has consulted for dozens of pro and college teams and has presented workshops with seven NBA squads.
As an athlete in college, Taft recalled his coaches trying to get him to stop the maneuver, saying it was wasted movement before forward propulsion. Taft, however, began studying it once he started his career in strength and conditioning.
He realized the false step goes far beyond sport and is a remnant of our most basic instincts. Taft cross-referenced footage of animals being suddenly startled by predators and saw similar acts of them repositioning their feet.
“It falls under our fight or flight reflexes,” Taft told USA TODAY Sports. “So anytime we’re scared or we need to take off really quickly – something frightens us and we take off – this is a natural reaction to reposition your feet so you can escape harm very quickly or attack.”
Put another way: it’s extremely difficult to train something out of people when it’s instinctual.
A hypothesis raised by some experts suggested that a rise in pace in the NBA may be a contributing factor to the increase in ruptures. And while possessions per season have steadily increased in recent seasons, pace today is nowhere near the record highs from the 1960s.
An examination of vintage game footage shows how players relied on handoffs and focused on creating space for jump shots. Today, with the emphasis of the 3-point shot, teams are embracing speed to create mismatches, sucking defenses into the low block.
“The obsession around paint touches, particularly direct-line drives, just to create spacing for perimeter shooting and shots at the rim – there’s a huge uptick in maneuvers where you have to false step,” Petway said.
The future of Achilles tendon rupture prevention
The NBA is continuing its work with the panel of experts and plans to present findings to all 30 teams. As part of that initiative, the league is consulting specific teams that are proactive with their imaging and methods to measure elastography – or tendon stiffness. The NBA will also continue to track the false step and look into whether specific players are using it more often than others.
Essentially, the NBA is trying to amass all the data points it can to create a common denominator
Players and coaches, meanwhile, can embrace exercises like controlled heel drops and other plyometric exercises to improve tendon strength and stiffness. Deep tissue massages also can support circulation and improve blood flow and tissue health. Maintaining flexibility, experts said, is also key.
Above all, however, the NBA is stressing caution with any interventions they’re considering.
“We don’t want to chase down something that has a negative consequence for the players or introduce something that could actually increase injuries,” Dr. John DiFiori, the league’s director of sports medicine, told USA TODAY Sports. “If we make a change with something around the ankle or the foot, we may or may not be solving Achilles ruptures, but then are we creating a problem somewhere else in the kinetic chain? We need to be very thoughtful about it.”