Table 3 Details of the spinal manipulation intervention

Chaibi (2017) [27]

“SMT group received spinal manipulative therapy using the Gonstead method, a specific contact, high-velocity, low-amplitude, short-lever spinal with no post-adjustment recoil that was directed to spinal biomechanical dysfunction (full spine approach) as diagnosed by standard chiropractic tests at each individual treatment session”

Munoz-Gomez (2021) [26]

“low velocity and moderate to high amplitude movements were conducted on the neck and upper-trunk joints and sacroiliac joints to force their full range of motion. Specifically, the following techniques were applied bilaterally in all treatment sessions (Dunning et al. 2016): occiput-atlas-axis articulatory manipulation, upper cervical spine (C0–C1) mobilization, middle cervical spine (C2–C7) mobilization in supine, middle cervical spine (C2–C7) mobilization in prone, cervicothoracic junction articulatory manipulation, upper thoracic spine (T2-T6) articulatory manipulation and global sacroiliac joint articulatory manipulation.”

Nelson (1998) [32]

Spinal manipulation 14 times over 8 weeks (no more than 2 times per week)—preceded by 5–10 min of massage and/or trigger point therapy

Parker (1978) [34]

“ (…) the chiropractors were required to manipulate the cervical spine. […] “The chiropractors were free to manipulate other parts of the spine on members of this group”. Frequency: no more than twice weekly for 2 months

Rist (2021) [25]

“All treatments applied in this study were within the scope of chiropractic practice in the Commonwealth of Massachusetts and included: posture correction and spinal stabilization exercises, soft tissue relaxation/release techniques, spinal manipulation and joint mobilization, relaxation techniques, education, stretches, and ergonomic modifications”

Tuchin (2000) [33]

“Two months of chiropractic SMT (diversified technique) at vertebral fixations determined by the practitioner (maximum of 16 treatments).”