How should a long back stretch on the reformer be modified for a client with thoracic outlet syndrome?

When considering how to modify a long back stretch on the reformer for a client with thoracic outlet syndrome, the best approach is to omit the exercise entirely. This condition can result in pain or discomfort caused by compression in the thoracic outlet, which is the space between the collarbone and the first rib. The long back stretch may provoke symptoms due to the position and movements it requires, potentially exacerbating the compression.

Choosing to omit the exercise ensures the client's safety and comfort, allowing them to avoid any exacerbation of their symptoms. It is important for individuals with thoracic outlet syndrome to focus on exercises that promote proper posture, strengthen the surrounding musculature, and relieve tension rather than performing movements that could worsen their condition.

The other options, such as adding weights, changing the range of motion, or switching to a seated position, can still place strain on the neck and shoulders, potentially contributing to discomfort or pain related to the syndrome. Thus, modifying the exercise by completely omitting it is the safest and most prudent choice for someone experiencing this condition.