During field assessment for suspected injury, why is comparing with the contralateral limb useful?

• A. To assess symmetry in swelling, deformity, and functional ability.
• B. To rely on it for blood pressure.
• C. To evaluate breathing pattern.
• D. To assess symmetry in swelling, deformity, and functional ability.

Answer: (D)

Using the opposite limb as a reference provides a personal baseline for symmetry in swelling, deformity, and functional ability. In the field, you can’t rely on imaging, so you look for differences between the injured limb and what the person’s own healthy limb can do. If the injured side is more swollen, misaligned, or shows reduced movement or weight bearing compared with the other side, those differences point to injury and help you judge its likely severity. This approach helps distinguish true injury-related changes from natural asymmetry or prior conditions. It’s not about blood pressure or breathing pattern, which are assessed by other signs. The key idea is to assess symmetry in swelling, deformity, and function relative to the uninjured limb.