How do you stabilize the casualty's head when performing the jaw-thrust technique?

The jaw-thrust technique is used to open an airway in a casualty who may have a spinal injury or where traditional methods of opening the airway could potentially cause further harm. Stabilizing the head is crucial during this process to prevent any movement of the cervical spine, which could lead to additional injury.

Placing a forearm on each side of the casualty's head effectively stabilizes it by providing a firm, controlled hold. This method helps to maintain the head and neck in a neutral position while the jaw-thrust is performed. With your forearms on either side, you can open the airway without unnecessary manipulation of the head and neck, minimizing the risk of exacerbating any spinal injuries.

The other methods mentioned, such as using your knees or resting the head on a flat surface, do not provide the same level of stabilization and control necessary for safely performing the jaw-thrust maneuver. Applying pressure to the chin might inadvertently cause the head to tilt, which could compromise spinal alignment and affect the casualty's condition adversely. Therefore, using forearms on each side is the most effective and safe way to stabilize the casualty's head during this procedure.