The longer you are inactive, the weaker your muscles can become.

Then it seemed to slow, its muscles becoming tense, and the tail stuck straight up in the air.

Twelve hours after death, the muscles have become fully rigid.

The muscles in my calves have become extremely sore and stiff.

It seemed pointless to sit there any longer; his muscles were becoming stiff with cold.

When muscles become stronger or swifter, their proteins change in number and distribution.

She wanted to lean back, but her muscles had become paralysed.

It cannot properly fill with blood because the muscle has become stiff, losing its ability to relax.

The brain can then decide which muscles in the body need to become active in order to right itself.

At night, the muscles that help keep your airways open relax and become floppy.