A cervical collar is a medical device used to support and limit movement of the neck (cervical spine), usually following an injury or surgery. This restraint maintains proper spinal alignment, preventing secondary damage and facilitating healing. Selecting the correct size is important because an improperly fitted collar can be ineffective, potentially positioning the head incorrectly. Incorrect sizing can also lead to complications like restricted breathing or increased pressure on major blood vessels.
Preparing for Accurate Measurement
Before measurement, the patient must be positioned in a neutral, straight-ahead alignment. For those with a suspected spinal injury, this neutral position is maintained while they are lying supine (flat on their back) to prevent spinal movement. Stable individuals measuring themselves should sit or stand upright, looking straight ahead without tilting the head.
Accurate measurement requires two distinct tools: a flexible tape measure for circumference and a rigid device, such as a ruler or sizing guide, for vertical distance. A mirror or a second person can help ensure the tape remains level around the neck.
Step-by-Step Measurement Technique
The first step is determining the neck’s circumference, which dictates the collar’s overall size category. Wrap the flexible measuring tape around the thickest part of the neck, often just below the Adam’s apple, ensuring the tape is parallel to the ground. The measurement should be snug against the skin but not so tight that it compresses the soft tissue.
The second measurement is the vertical distance, which determines the collar’s height setting. For rigid, adjustable collars, this is the distance between the underside of the chin and the top of the sternal notch (the dip at the base of the neck where the collarbones meet the breastbone). To measure this, a rigid ruler or straight edge is placed vertically, extending from the sternal notch up to the jawline.
A practical method used in medical settings involves using finger-breadths to quickly gauge the distance between the sternal notch and the chin. The number of fingers that fit snugly in this space is then matched to corresponding adjustment settings on the side of the collar. After obtaining both measurements, these numbers must be cross-referenced with the manufacturer’s sizing chart to ensure the chosen device matches the patient’s anatomy. These charts translate the raw measurements into the correct collar size and height setting, such as “short,” “regular,” or “tall.”
Applying and Assessing Proper Fit
Once the collar size and height have been selected, proper application is necessary to ensure therapeutic benefits. For a two-piece rigid collar, the back piece is typically slid underneath the patient’s neck first, maintaining neutral alignment. The front piece, which contains the chin cup, is then brought up against the front of the neck.
The chin must rest securely in the molded cup of the front piece, which supports the weight of the head. The chin should not be able to retract or slide out of the cup, which could lead to hyperextension or hyperflexion of the spine. The two pieces are then secured with the Velcro straps on the sides, ensuring they are even and hold the collar firmly in place.
A properly fitted collar should significantly limit the person’s ability to move their head. The fit must be verified to ensure it does not compromise breathing or circulation. Signs of a poor fit include excessive skin irritation, pain, difficulty swallowing, or restricted air flow. The collar should be snug enough to restrict motion but loose enough that two fingers can be comfortably slid between the collar and the neck at the top and bottom edges.