I’m posting this due to my concern for treating middle back spasm with medication and the possible dangers of combining that with heavy exercise.
As I understand it, middle back spasms indicate that alignment between hips and shoulders is inadequate. I cited the illiopsoas/illioacus set as pivotal in this area as it is their job to anchor the extension of the spine against twisting by anchoring the actions of the abdominals and spinalis groups. The action that the pectorals and latissumus dorsi maintain in drawing the sternum and shoulderblades down evenly as the trunk extends relies on the stability of the previously mentioned groups.
The concern I have with using medication to treat spasms in the middle of the back is due to the role that the spinalis thoracis plays in this action. In the proprioceptive sense, this muscle relates information between the intercostals and various mediator groups back to the pelvic floor groups and shoulder groups. Treating spasm here with relaxants may allow pinched to nerves to small muscles such as intercostals to become overlooked by the proprioceptive system, cutting out that muscles action without appropriate compensation. The alignment between the intercostals and illiopsoas/illiacus groups is vulnerable to any misalignment with so many small muscles relying on maximal spinal extension to maintain functional activation.
The point here I believe is that without attention to the weak areas that have caused the spasm, relaxants will only further weaken these areas inevitably. Ultimately it is not difficult to identify where trunk/limb extension may vary between sides and strengthen these areas. I am not cautioning against using medication, only that there may be longer term damage caused without attention to the rehabilitation of the weakened areas.
I also thought it wouldn’t be hard to develop a simple guide to identifying the source of various common back issues(if one has not already been created).