The 2009 Nissan Murano was the best performer in new crash tests of midsize sport utility vehicles, according to results released today by the Insurance Institute for Highway Safety.

The Hummer H3 had one of the poorest showings.

The institute, which is financed by the insurance industry, said the redesigned Murano was the only vehicle among the nine tested to get the highest rating in front, side and rear crash tests. It praised Nissan for making electronic stability control standard on the 2009 Murano.

General Motors Corp.’s H3 was the only vehicle in the group that didn’t get the top rating for frontal crash protection. Instead, it got the second-highest rating of “acceptable” because the test indicated high likelihood of injury to the driver’s right leg. The H3 also got an “acceptable” rating in the side crash test and the worst rating of “poor” in the rear crash test.

That measures the risk of injury from whiplash, which is the most serious injury reported in 2 million insurance claims each year. The institute said three vehicles — the Mitsubishi Endeavor, Mazda CX-7 and Mazda CX-9 — would have been top safety picks if they hadn’t performed so poorly in the rear crash test.

The institute’s frontal crash test simulates a 40-mph crash and its effect on the driver, and the rear test simulates a 20 mph test.

The side crash simulates what would happen if the vehicle was struck in the side by a sport utility vehicle at 31 mph.

The side crash test uses dummies in the front and rear seats.