He is doing special exercises to strengthen his psoas major muscle.

He exercises every day to strengthen his psoas muscle.

I strained a muscle at the gym yesterday.

He was dancing, swinging his hips.

He is doing special exercises to strengthen his iliopsoas muscle.

By strengthening the rotator lumborum, you can prevent lower back pain.

She was dancing, swaying her hips.

I achieved a big success.

The multifidus lumborum muscle is one of the important muscles that support our back.

He trains his gluteus maximus at the gym every day.