Table 2 Rationale for exclusion criteria

Pregnancy (real or suspected) and breast-feeding

These patients have a risk of some alteration due to the mechanical and thermal energy release

Subjects who received physical therapy treatments in the 15 days preceding T1

These treatments could influence the results of the study

Subjects treated with cortisone in the month preceding T1

This treatment could influence the results of the study

Subjects implanted with pacemakers and ICDs (implantable cardioverter defibrillators); more generally, users of active implantable devices

In order to prevent possible electromagnetic interference between SMATH^® and the implantable device, which is potentially dangerous for the patient (cautelative criteria)

Subjects with medullar stimulators and infusion pumps with recent or ongoing DVT (deep venous thrombosis)

To prevent possible electromagnetic and mechanical interference between SMATH^® and the implantable device, which is potentially dangerous for the patient (cautelative criteria)

Subjects with spine stabilization devices

These treatments could influence the results of the study

Subjects with serious osteoporosis associated with bone fracture risk

Mechanical energy release on these patients could increase bone fracture risk

Subjects with logically soft or acute infection of bone tissues

Thermal and mechanical energy release could increase infection diffusion

Subjects with acute cardiovascular disease

These patients need to be submitted to specific clinical evaluation before being treated for LBP

Subjects with neoplastic disease

These patients need to be submitted to specific clinical evaluation before being treated for LBP

Subjects with systemic rheumatic disease

These patients need to be submitted to specific clinical evaluation before being treated for LBP.

Subjects with traumatic spinal episodes the 3 months preceding T1

Mechanical energy release on these patients could be dangerous.