He is suffering from muscle pain in his semispinalis muscle.

The semispinalis capitis muscle is a part of the neck muscles, helping to tilt the head backwards.

The semispinalis thoracis muscle is a deep muscle in the back that supports movement from the neck to the waist.

The semispinalis cervicis muscle is a part of the neck muscles, helping to pull the head back.

He is suffering from illness.

He is doing special exercises to strengthen his spinalis muscle.

He is working out his muscles at the gym every day.

He lived in Japan for a year and a half.

I strained a muscle at the gym yesterday.

He is my best friend.