Mobility
Open Book Thoracic Rotation
The Open Book Thoracic Rotation is a side-lying mobility exercise that moves your upper back through gentle rotation while stretching your chest and shoulders.
- Beginner
- Low injury risk
- No rest timer
How to do it
- Lie on your side with your hips and knees bent about 90 degrees, knees stacked.
- Reach both arms straight forward at shoulder height, palms together.
- Rotate your chest toward the ceiling, letting your top arm open out to the opposite side.
- Pause briefly at the end of your comfortable range.
- Reverse the rotation to bring your top hand back onto your bottom hand.
Form cues
- Keep your hips still.
- Exhale slowly as you open.
- Follow your hand with your eyes.
- Let your shoulder stay relaxed.
Common mistakes
- Top knee liftingKeep your top knee resting on the bottom knee so the movement comes mainly from your upper back.
- Reaching without rotatingLet your ribs turn with your arm rather than pulling the arm behind a stationary chest.
- Rushing through repetitionsTake several seconds to open and return rather than swinging your arm.
Safety
Forcing your hand toward the floor can strain your shoulder, while pushing rotation beyond your available range can irritate your back or neck.
- Support your head with a folded towel if it tilts toward the floor.
- Let your open arm hover or rest on a pillow rather than pressing it down.
- Stop if you feel sharp pain, tingling, numbness, or dizziness.
If you have an ongoing back, neck, or shoulder problem, use a smaller range or ask a physiotherapist whether this movement is appropriate.
Muscles worked
Primary muscles
Secondary muscles
Equipment
No equipment needed.
Sets and reps
- Sets
- 1–2
- Target
- 6–10 reps per side
- Rest
- No rest timer
Complete your repetitions on one side before switching sides.