May 2 (HealthDay News) -- Resistance training with free weights can help workers with severe rotator cuff injuries return to their jobs, a new study says.

Rotator cuff injuries -- which involve the muscles and tendons that stabilize the shoulder -- can occur when the arm is pulled out of place in falls or other types of accidents.

The study, conducted by researchers at the Athletic and Therapeutic Institute in Chicago, included 42 people who weren't able to return to work after undergoing traditional physical therapy following surgery to repair their torn muscles or ligaments.

The participants took part in a six-week program where they trained for four hours a day, five days a week. The daily program began with warm-up, stretching and core exercises for balance and proper biomechanics. That was followed by free weight resistance training of the upper and lower body.

On some days, the participants did exercises designed to simulate the type of physical labor they did at work.

Through this training program, 90 percent of the participants were able to start working again, and 75 percent of them were able to go back to their previous jobs.

The study was to be presented at the Experimental Biology meeting now underway in Washington, D.C.