The internal anal sphincter is a muscle that helps us control defecation.

The internal urethral sphincter plays a crucial role in controlling the flow of urine.

He was deeply thinking about '稽'.

The internal oblique muscle is a muscle that helps with the body's rotational movements and lateral bending.

He is doing special exercises to strengthen his adductor brevis.

His pronator teres was aching from muscle soreness.

He is doing a special exercise to strengthen the pronator quadratus muscle.

She started a special exercise to strengthen her adductor pollicis.

By strengthening the adductor hallucis, you can maintain the health of your feet.