Open book stretch
A side-lying rotation that improves upper-back mobility. Count each slow opening as one rep.
- Muscle group: Mobility
- Equipment: Bodyweight
- Difficulty: Beginner
Also known as: Open book, Thoracic rotation, Side-lying thoracic rotation, Åben bog
How to do it
- Lie on your side with knees bent to hip height and arms straight in front of you, palms together.
- Keep the knees together and open the top arm across your body like a book, following it with your eyes.
- Pause, breathe out, then close slowly. Do all reps, then switch sides.
Common mistakes
- Letting the knees slide apart so the lower back twists instead.
- Forcing the arm to the floor.
Alternatives
Watch a video demonstration on YouTube
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General technique guidance, not individual advice. Stop if something hurts and talk to a professional about injuries.