Which exercise is NOT typically aimed at increasing spinal mobility on the Reformer?

The exercise that is not typically aimed at increasing spinal mobility on the Reformer is Single Leg Bridging. This movement primarily focuses on strengthening the muscles of the glutes, hamstrings, and lower back while providing a stable basis for the pelvic region. The primary goal of Single Leg Bridging is to engage and strengthen the muscles that support the pelvis and lower spine, rather than specifically promoting movement through the spinal column itself.

In contrast, the other exercises—Jackknife, Long Spine Massage, and Long Box Rocking—are designed to enhance spinal articulation and mobility. The Jackknife involves a dynamic motion that encourages spinal flexion and extension while bringing the legs over the head, promoting flexibility and strength along the spine. The Long Spine Massage emphasizes rolling the spine in and out of extension and flexion for mobility and alignment, while Long Box Rocking encourages fluid movement and stretches the spine, enhancing its overall flexibility. By focusing on these elements, the exercises collectively contribute to improved spinal health, which is why Single Leg Bridging stands out as the outlier in this context.