Why should crutches not rest under the arm for support?

Crutches should not rest under the arm for support primarily because this position can injure the brachial plexus nerves. When crutches are positioned incorrectly under the arm, significant pressure is placed on the area, which can lead to nerve compression and damage. The brachial plexus consists of a network of nerves that innervate the shoulder, arm, and hand, and prolonged pressure from the crutch can disrupt the normal functioning of these nerves, potentially resulting in pain, weakness, or numbness in the arm and hand.

Proper use of crutches involves positioning them a few inches to the side and in front of the feet, with a slight bend in the elbows, to ensure that weight is distributed correctly on the hands rather than on the underarms. This method not only promotes safer gait mechanics but also reduces the risk of developing nerve injuries and other related complications.