Normal Range of Motion in Back Extension and Flexion

Your back is a sophisticated structure made up of bones, muscles, connective tissue and nerves that allow you to bend and flex at the waist. A person with a normal range of motion is able to reach towards the ceiling and then touch his toes while keeping his knees straight. Physicians and medical professionals report range of motion in degrees, measuring your ability to bend forward and lean backward without stiffness or pain. If you have your range of motion tested, the results will be noted on a form, comparing your ability with the normal range of motion values established by the American Medical Association guidelines.

Testing Your Range

Doctors describe your spine as having three sections, each responsible for moving different parts of your body. A doctor reports a person who can move freely without pain or stiffness as having 100 percent range of motion. She might ask a patient with back pain or stiffness to perform various ranges of motion movements and then describe the patient’s disability as a percentage of the normal value. For example, a person who can only bend halfway over has 50 percent range of motion. The physician will then prescribe a course of treatment to help the patient resume a normal range of motion for back extension and flexion.

Flexion and Extension

The stacked vertebrae configuration of your spine allows for flexion, extension, lateral flexion and rotation. You are engaging in flexion when you bend forward at your waist, moving your head towards your knees. You extend your spine when you arch your back and look towards the ceiling. Normal range of motion of your back also includes lateral flexion in which you raise one shoulder while dropping the other, arching your spine towards the left or right of your hips.

Cervical

Your cervical region has the greatest range of motion as compared to your thoracic or lumbar regions, according to the Mayfield Clinic for Brain and Spine. Your cervical spine supports the weight of your head. A person with normal range of motion for the cervical spine nods his head by flexing and extending the muscles that control his cervical spine. Normal range of cervical motion is 60 degree cervical flexion and 75 degree cervical extension.

Thoracic

Your thoracic area has limited range of motion. The main function of the twelve thoracic spinal vertebrae is to protect the organs in your chest, such as your heart and lungs, by providing an attachment point for your ribcage. You can flex, or bend, your thorax only about 50 degrees.

Lumbar

The main function of the lumbar, or lower, area of your back is to bear the weight of your body. ExRx.net states that you suffer an increased risk for lower back injuries during lumbar spine extension activities. But these back extension exercises are necessary to increase lumbar range of motion for patients suffering from lower back problems. Normal range of motion for the lumbar region is 60 degree flexion and 25 degree extension.