When a cast is removed why does the leg appear smaller?

Muscle Atrophy

When a limb is immobilized in a cast for an extended period, the muscles within that limb begin to atrophy or waste away. This is because the muscles are not being used and therefore do not receive the necessary stimulation to maintain their size and strength.

Loss of Fluid

When a limb is immobilized, the blood flow to that limb is restricted. This can cause fluid to build up in the limb, leading to swelling. When the cast is removed, the fluid drains away, and the limb may appear smaller.

Compression of Nerves

In some cases, a cast can put pressure on the nerves that supply the muscles in the limb. This can also lead to muscle atrophy and a smaller appearance.

It is important to note that the smaller appearance of a limb after a cast is removed is usually temporary. With proper rehabilitation and exercise, the muscles can regain their size and strength over time.