For an instant, his muscles bunched to carry him forward again.

Small muscles in her left arm were bunching to balance the heavy case.

His muscles bunched as he slid the heavy case into position.

His muscles bunched as if they were bracing for a fall.

The muscles in his arms and shoulders bunched as he hauled himself out of the water.

Tom opened the rear door and reached in, back muscles bunching, as he pulled on something.

Muscles bunched and swelled in his arms when he did that.

A little tap on my door made me jump, every muscle bunched with fear.

Her muscles bunched for the run through the street.

The muscles in his arms bunched, and veins stood out on them like cords.