Stanford Study Finds Driving To The Basket Elevates Chances Of An ACL Tear
SAN FRANCISCO (CBS SF) -- The scene still lingers in the minds of Golden State Warriors fans -- star Klay Thompson on the court, writhing in pain, holding his knee during the 2019 NBA Finals.
It was the last time he was on court for the Warriors. He torn his ACL on the play and while rehabilitating that injury, tore his Achilles tendon.
Nearly two years later, he is preparing to finally return to the lineup, a significant roster addition to a team off to an 8-1 start.
According to a Stanford medical study released over the weekend, he would have been better served relying on his deadly touch from the 3-point line instead of driving to the basket for a dunk.
The researchers found that the more often a professional basketball player drives the ball toward the basket to score, the higher the risk of an anterior cruciate ligament tear.
The study results showed that players with high career driving tendencies experienced ACL tears at a rate of 5.2% compared with those with lower driving tendency, who experienced tears at rates of 3.8%.
There was also some encouraging words for Thompson and Warriors fans -- those who return to play after ACL reconstruction come back just as strong as their healthy counterparts.
"Our study showed that not only do players perform just as well as uninjured players of equal caliber after ACL reconstruction, but they also do this without having to reduce their driving," said Dr. Blake Schultz, an orthopedic trauma fellow at the University of Texas who was a Stanford surgical resident at the time of the study.
Also involved in the study was Dr. Geoffrey Abrams, a Stanford associate professor of orthopaedic surgery who is also the assistant team physician for the San Francisco 49ers.
"Our study provides information to players, teams and medical staff that individuals who return to elite-level competition after undergoing ACL reconstruction surgery are likely able to make a full comeback," Abrams said.
Shultz developed the idea for the study three years ago when he was helping treat patients with ACL injuries. He had patients asking him what they could expect upon their return to the basketball court.
"They wanted to know if they would be able to be as explosive and drive to the basket as well," he said. "I wasn't sure what to tell them. Now I can say, 'You will be able to return to the same level of play and expect to be as efficient at driving.'"
An ACL tear always leads to surgery and months of rehabilitation. It also raises doubts about the injured player's chances of returning to normal.
"An ACL is always a big concern of athletes," said Jerod Haase, head basketball coach at Stanford. "You pretty much know if it is an ACL, it's going to be season ending."
The ACL is a band of tissue that connects the thigh bone to the shin bone and is crucial for knee stability. Surgical reconstruction involves removing the damaged ligament and replacing it with a segment of tendon from another part of the knee or a deceased donor.
Using publicly available data gathered primarily from online sources, including injury reports and news releases, researchers identified 97 NBA players who had ACL tears since 1980. They excluded athletes who played before 1980 because the 3-point shot was introduced that year, which significantly changed statistics.
From those 97 players they winnowed the number down to 50 for analysis: They excluded players for reasons including playing in another league after their injury or suffering a previous ACL tear.
Data on how frequently players drive to the basket has been kept by the NBA only since 2013, but the researchers needed this information for three prior decades of games. To overcome this challenge, they collected 49 more traditional statistics related to style of play, then developed an algorithm to estimate players' driving tendency from those statistics.
The researchers developed another algorithm to match each ACL-injured player with two other NBA players of similar age and playing styles who had not torn their ACLs.
As an example, the algorithm matched NBA player Ron Harper — the Los Angeles Clippers leading scorer before he tore his ACL in 1990 — with NBA players Paul Pressey and Scottie Pippin, said Kevin Thomas, an MD-PhD biomedical informatics student at Stanford, who took part in the study.
"Right before getting injured, Harper looked a lot like Pressey in 1985 and Pippen in 1991," Thomas said.
Researchers then compared the remaining years in each of the three players' careers, adjusting for aging. When these comparisons were done for each injured player, no significant difference in performance levels or changes in style of play were seen between the two groups, the study said.
"Everyone assumes they are coming back worse than they were before," Thomas said. "We were really excited to find that wasn't the case."