Kids with cerebral palsy often undergo aggressive surgeries to improve their movement, but now researchers say they have a better idea who is most likely to benefit from such procedures.

A new study suggests that data derived from an electromyography, or EMG, — a common tool to monitor muscle activity — can be evaluated to determine whether surgery to lengthen tendons, rotate bones or transfer muscles to new locations is a good bet.

“Only about 50 percent of children have significant improvement in their movement after these highly invasive surgeries,” said Katherine Steele, an assistant professor of mechanical engineering at the University of Washington and an author of the study published online in the journal Developmental Medicine & Child Neurology.

“Our motivation has really been to figure out how we can push up these success rates,” she said.

For the study, researchers looked at 473 kids with cerebral palsy who had undergone surgery. They assessed EMG data from the children before surgery using a quantitative assessment known as Walk-DMC and found that those with higher scores had better outcomes from the procedures even when factoring for age and prior treatment.

“These results suggest that motor control is uniquely and independently associated with outcomes and can help us decide when you might recommend surgery and when you might be more conservative in treatment,” Steele said.