SAN FRANCISCO (AP) — Amusement parks are not financially responsible for injuries suffered on bumper cars, the California Supreme Court ruled in an opinion published Monday.

The high court said people who ride bumper cars under normal conditions automatically assume some risk — just as people who play football or other sports — and cannot sue after being injured.

"A small degree of risk inevitably accompanies the thrill of speeding through curves and loops, defying gravity or, in bumper cars, engaging in the mock violence of low-speed collisions," Associate Justice Kathryn Werdegar wrote. "Those who voluntarily join in these activities also voluntarily take on their minor inherent risks."

The ruling does not absolve parks from their legal duties to maintain the safety of rollercoasters, which the court distinguished from bumper cars.

The opinion reversed a state appeals court ruling in favor of Smriti Nalwa, who filed a lawsuit after breaking her wrist on the "Rue le Dodge" bumper car ride in 2005 at Great America park in Santa Clara.

Nalwa was riding with her 9-year-old son, who was driving, when they were hit from the front and then from behind. Nalwa sought to brace herself on the car's "dashboard," and her wrist broke, the lawsuit states.

The trial court sided with park owner Cedar Fair L.P., saying the park had no control over the steering and operation of the individual bumper cars and patrons took an inherent risk in participating.

A state court of appeal disagreed, saying the inherent risk of playing a sport was not the same as driving a bumper car. The court also said the park could have done more to reduce the threat of a head-on collision.

In its opposing opinion, the California Supreme Court said riding bumper cars carries some risk of injury, and that frees the parks from liability for those injuries.