The thoracic spine is a difficult joint to measure because of its connection to the cervical and lumbar spine. The location of the thoracic spine makes it difficult to isolate for measurement, so a device called an inclinometer is often used to measure it. Depending on the position of the patient, you may choose instead to use a goniometer to measure the rotation of the thoracic spine, but it is more difficult.
Function
Many sports and daily activities require a full range of motion of the spine. If the spine has limited mobility, it may result in stiffness or pain and require a doctor or physical therapist's help to regain a full range of motion. The inclinometer or goniometer is used to assess the patient's range of motion in the thoracic spine to see if there are any deficiencies.
Types
Two instruments are often used to determine the range of motion of the thoracic spine. The goniometer is used for patients in a seated position, while an inclinometer is often used to measure the thoracic spine of a patient in a bent over position. Both instruments indicate any deficiencies in the thoracic spine's range of motion; however, some experts argue that the inclinometer gives a more accurate reading. The American Medical Association's Guides to the Evaluation of Permanent Impairment adopted the inclinometer as the device to use to measure spinal range of motion because its readings are more accurate, precise, and reproducible than those of the goniometer.
Using a Goniometer
If the patient is seated and is not able to easily bend forward and get on all fours due to joint, balance or other problems, a goniometer should be used to measure the spine's range of motion. Place a small ball between the knees of the patient to reduce the movement of his hips and place a straight bar across his chest, instructing the patient to cross his arms in front of his body to hold the bar in place. The bar will reduce the shoulder movement. Stand so you can look down on the top of the patient's head and line the fulcrum of the goniometer up with the top of the spine, making sure the arms of the goniometer are parallel with the stick. Keeping the stationary arm in place, ask the patient to rotate his spine, and move the movable arm of the goniometer along with the patient. Read the range of motion in degrees at the end of the movement.
Using an Inclinometer
Place the patient on the examination table in a quadruped position with her bottom as close to her heels as possible and her elbows tucked in toward her knees. The flexed hip position helps stabilize the hip joints so the movement does not interfere with the spine's range of motion. Place the inclinometer between the spines of the T1 and T2 vertebrae. The patient should place one hand on her head and rotate her spine, moving in the direction of the lifted arm. Read the inclinometer when the patient's motion stops.
Warnings
Measurements of the thoracic spine should be performed in a seated, quadruped, or half-kneeling position to minimize the motion of the surrounding joints, such as the hips and shoulders, which may assist in the trunk's rotation, leading to an inaccurate reading of the spine's range of motion. Watch for signs of compensation during the range of motion. If the patient is seated, you may see him side bend as he rotates. This will be noticeable by the stick dropping lower rather than staying in a flat plane throughout the motion. If the patient is bent over, you may notice him shifting his weight during the rotation or shifting his hips forward or backward to assist in the rotation.
References
- "Journal of Neurosurgery Spine"; Measurement of spinal range of motion in healthy individuals using an electromagnetic tracking device.; CJ Hsu, et al.; Feb. 8, 2008
- NAJSPT: Thoracic Rotation Measurement Techniques--Clinical Commentary; KD Johnson et al; Dec. 2010
- Physical Therapy of Los Gatos: What is an Inclinometer?
