Muscle · Thoracic spine

Spinalis

Musculus spinalis

The smallest, thinnest and most medial of the three erector spinae columns — a slender strap that runs from spinous process to spinous process right against the midline of the upper back. It is the least substantial of the three and the most variable between people, and in the thoracic region it is often difficult to tell apart from longissimus at all. Its clinical value is as the completion of the picture rather than as a target in its own right: it belongs to the same postural column the founder's system reads as compensating when the hips and deep core stop working.