A little extra cushioning in the shoe may prevent a small crack in a tiny foot bone that can end a basketball player’s season, a study suggests.
And arch supports likely could also help protect weekend athletes, particularly those with flat feet, researchers say.
The little bones in the foot take a lot of punishment.
“The forces proven to occur just from landing following a jump are greater than five times body weight,” said Dr. Joseph Guettler, a researcher and orthopedic surgeon at William Beaumont Hospital in Royal Oak, Mich.
The study focused on the fifth metatarsal, a bone about a half inch wide and 3 to 4 inches long, which runs along the top outside edge of the foot.
Electronic shock absorbers
The foot bones are held together by a web of muscles, tendons and ligaments. They absorb the shocks, twists and stretches that come as an athlete runs and jumps.
The accumulated stress can create tiny breaks that develop into bigger ones, said Guettler, who studied bone stress while an orthopedic fellow at Duke University. He presented his findings at a recent meeting of the American Academy of Orthopaedic Surgeons.
Guettler and his colleagues studied 11 players from North Carolina Central University in Durham. The players wore very thin electronic insoles that transmitted data on foot pressure as they made one-foot landings after jumps, and did two reverse-direction moves — a shuffle and a forward sprint.
Using the insoles, the researchers measured the players with and without extra arch support in their shoes.
Forces on the fifth metatarsal were consistently greater without the arch support, the study found, suggesting that cushioning the arch could reduce stress.
If that’s the case, the finding could have important implications for basketball players, since injuries can take six weeks or more to heal, Guettler said.
Although the study looked at collegiate players, he noted the same principles would apply to recreational basketball players and others whose sports require pivoting and jumping.
In addition, all the players in the study had some degree of flat-footedness, a common condition in basketball, Guettler said. Since people with flat feet are more likely to get stress fractures, he said, they ought to use arch supports.
Shifts stress away
The supports also likely would help people with high arches, because other studies have found they, too, have higher risks of injury to the fifth metatarsal, he said.
Guettler says the most effective supports are probably custom-fitted. But those can cost several hundred dollars, and even cheaper, store-bought supports provide some benefit.
The arch support seemed to shift stresses away from the fifth metatarsal, said Dr. Jonathan Chang, an assistant professor of orthopedics at the University of Southern California. Chang was not part of the Guettler study but saw the presentation.
If an arch support does prevent injury, even a custom support could be worth the money by heading off a fracture that “could make or break an entire season,” Chang said.
Still, it will take more tests to know whether what was true of Guettler’s 11 players is true of players in general, Chang said. “Some would jump on it immediately, others would say, ’I want to see more proof first,”’ he said.
Chang is among those reserving judgment.