Develop genuine thoracic spine rotation with this side-lying open-book drill — a precise, well-controlled movement that isolates rotation to the thoracic spine by locking the pelvis and hips firmly in place, ensuring every degree of rotation is coming from exactly where it needs to.

Lying on your side with the knees pulled toward the chest at approximately 90 degrees, a yoga block or foam roller is squeezed firmly between the knees throughout the entire movement. This is not a passive prop — actively squeezing the block locks the pelvis and hips down, preventing them from rotating and ensuring the lumbar spine and lower body stay completely still. Starting with the palms pressed together and the arms extended in front of the chest, the top arm peels away and reaches over to the opposite side — opening the book — rotating only through the thoracic spine and reaching as far as possible without any compensation through the lumbar spine, pelvis, or hips. The movement is slow, deliberate, and fully controlled in both directions.

The thoracic spine is designed for rotation — it is where the majority of spinal rotation should occur. However, most people have lost significant T-spine rotation due to prolonged sitting, poor posture, and anterior-dominant training patterns, and have compensated by rotating through the lumbar spine and hips instead. The side-lying position with the block between the knees directly addresses this compensation pattern — by locking the hips and pelvis down, the body is forced to find rotation from the thoracic spine rather than stealing it from below. The slow, controlled tempo ensures the movement is intentional and that end range is genuinely reached rather than swung through. Reaching as far as possible at end range creates a mild active stretch through the thoracic rotators, building both mobility and awareness of where T-spine range actually begins and ends.

This should feel like a slow, deliberate opening through the upper and mid back — a sensation of the ribcage and chest rotating away from the hips while the lower body stays completely anchored. The block squeeze should feel constant and active throughout. Any movement of the pelvis or hips signals that the thoracic range has been exhausted and the body is compensating — reduce the range and find honest T-spine rotation instead. Over time, this drill restores thoracic rotation mobility, reduces compensatory lumbar loading, and improves rotational capacity for sport, overhead movements, and daily life.