In spinal immobilization of a child who has fallen from a height, which action should you take?

Applying padding under the patient's shoulder is an essential step in spinal immobilization, especially for a child who has fallen from a height. This action helps to maintain proper alignment of the spinal column and supports the natural curvature of the upper back. Proper padding is crucial in minimizing movement and providing stabilization during transit, ensuring that any potential spinal injuries are not exacerbated.

When spinal immobilization is being performed, maintaining a stable position is necessary to prevent further harm. By placing padding under the shoulders, it can also help to elevate the head slightly, which can aid in airway management if needed. The focus on ensuring that the spine remains in a neutral position can't be overstated in trauma situations, as misalignment can lead to additional injuries.

While other options may involve the use of padding or support, they do not specifically address the critical need for shoulder stabilization in spinal immobilization for a child, making this option the most appropriate choice in the given context.