The basketball court is a confined space, measuring 94 feet by 50 feet, but the ball does not always obey these restrictions. It can fly into the stands, and there are moments when players must make an all-important, split-second decision: Try to leapfrog a row of fans sitting courtside or, as the New York Knicks’ Lance Thomas put it, “hit the brakes.”

Said Thomas: “We’re large individuals. It’s not always easy to stop all that momentum.”

That much was apparent last Thursday night, when, while chasing after a loose ball, LeBron James injured professional golfer Jason Day’s wife, Ellie, who was sitting courtside at Cleveland’s Quicken Loans Arena with her husband.

“I think every NBA player has had close calls like that,” the Knicks’ Derrick Williams said. “With LeBron being his size and landing on that lady, it’s tough. Being 260 pounds and running full speed, he’s going to land on somebody.”

In no other major sport do fans sit closer to the area of play, and without any barriers between themselves and the athletes. The spectator experience, at least for those fortunate enough to sit courtside, is enhanced by that rare type of intimacy. Most fans seem willing to accept any minor risks in lieu of sitting behind signage or covering themselves in Bubble Wrap.

The collision involving James came at a time when baseball is dealing with the danger of foul balls and potentially costly lawsuits that can result from them.

Basketball fans, Williams said, want to sit courtside, and they pay lavish amounts for the privilege. But on rare occasions, they get a little too close to the action.

Late in the Cavaliers’ victory against the Oklahoma City Thunder, James went after a loose ball and barreled into Ellie Day. She tumbled backward as the 6-foot-8 James landed on her.

James returned to the court but then called for a timeout when the Cavaliers regained possession. Medical personnel quickly tended to Day, who was strapped to a stretcher and transported to a nearby hospital. She was later released with what Bud Martin, who is Jason Day’s agent, described to The Associated Press as concussion-like symptoms.

Jason Day retweeted on Friday a message from his wife on his verified Twitter account in which she compared being run over by James to being in a “minor car accident.” She added, “My whole body feels like it was hit by a truck.”

She also defended James, saying he was simply moving too fast to avoid her. In other words, accidents happen.

“Much like attending a golf event and getting hit with a ball, sitting courtside you risk getting run into,” Ellie Day wrote, adding, “They’re huge men doing their job.”

Collisions with spectators are freak occurrences at NBA games. Derek Fisher, the Knicks’ coach, said he had largely been able to avoid running into fans during his playing career.

“But I never was moving as fast or as explosive as he was,” Fisher said, referring to James. “As players, guys are trying their hardest to make the right plays.”

In 2003, Jason Kidd, then playing for the Nets in New Jersey, broke his 4-year-old son’s collarbone when he went after a loose ball and wound up jumping into the stands.

Last season, Mason Plumlee, as a member of the Nets in Brooklyn, bumped into a waitress during a game against the Washington Wizards at Verizon Center. The only casualty was a huge tray of beer, the contents of which doused several fans in the vicinity.