As the most flexible joint in your body, your shoulder can move and position your arm in many ways. But this flexibility also makes it prone to instability, injury, and pain.

Shoulder muscles, ligaments and tendons can be injured by sports, household chores and heavy lifting.

These painful injuries sometimes take months to heal and can interfere with everyday tasks, the American Academy of Orthopaedic Surgeons says.

In 2010, about 16 million Americans visited their doctor for a shoulder problem, and more than 2.7 million were diagnosed with sprains and strains of the shoulder and upper arm, according to the academy.

"Strengthening and stretching the muscles that support your shoulder joint can keep it stable and restore range of motion to help reduce the risk of injuries," orthopedic surgeon Dr. Brent Ponce, an academy spokesman, said in an academy news release.

"If you suspect unusual pain in the joint, do not ignore it. Seek professional care to avoid further damage," added Ponce, who specializes in shoulder injuries.

He suggested certain exercises to strengthen the shoulder muscles:

• For basic shoulder strengthening, attach a stretch band to a doorknob at home. Gently pull the band toward your body and hold for a count of five. Repeat five times with each arm.
• Wall pushups are another exercise. Stand facing a wall with your hands on the wall and your feet shoulder-width apart. Slowly do a pushup and hold for a count of five. Repeat five times.
• There is also an upper back/shoulder blade exercise. Lie on your stomach with your arms by your sides. Gently pull your shoulder blades together and down your back as far as you can. Ease off by half from this position and hold for 10 seconds. Relax and repeat 10 times, Ponce said.