I strained a muscle at the gym yesterday.

This is a special day.

He cooked specially for me.

He is training his rectus abdominis muscle every day.

He is doing squats to strengthen his rectus femoris muscle.

He is doing special exercises to strengthen his superior rectus muscle.

He is doing special exercises to strengthen the lateral rectus muscle.

He is doing a special exercise to strengthen his inferior rectus muscle.

The rectus capitis anterior muscle is part of the neck muscles, helping to bend the head forward.

The medial pterygoid muscle is one of the important muscles for moving the jaw.