Summary of main characteristics of included studies
| Study ID | No of participants | Symptoms duration | Pain localisation | Technique tested (site of application) | Type of sham procedure | Other arms | Follow-up |
| Antonilos-Campillo, 201435 | 40 | Not reported | Cervical | Soft-tissue (cervical region) | Soft mobilisation of lower limbs | None | No follow-up (outcomes collected after the intervention) |
| Bialosky, 201425 | 110 | >4 months | Lumbar | Spinal manipulation (SM) (lumbar spine) | Ineffective force applied on lumbar spine | No treatment group | 2 weeks |
| Cleland, 200541 | 36 | >2 months | Cervical | SM (thoracic spine) | Ineffective force applied on thoracic spine | None | No follow-up (outcomes collected after the intervention) |
| Eardley, 201326 | 58 | >3 years | Lumbar | Kinesiology (spine) | Protocol of ineffective techniques in the site of pain | No treatment group | 7 weeks |
| Erdogmus, 200727 | 120 | ≥1.4 weeks | Lumbar | Physiotherapy (exercises of the spine and articular mobilisation techniques) | Neck massage | No treatment group | 1.5 years |
| Hall, 200646 | 24 | Not reported | Lumbar | BLR technique (lower limbs) | Soft-tissue manipulation of the foot | None | 24 hours |
| Haller, 201636 | 54 | >7 months | Cervical | Cranio-sacral therapy (head) | Ineffective touch of head | None | 3 months |
| Hansen, 199328 | 168 | ≥18 days | Lumbar | Physiotherapy (exercises of lumbar spine and abdomen, soft-tissues techniques) | Intermittent traction of the spine | Intensive back muscle training | 1 year |
| Hidalgo, 2015 | 32 | Not reported | Lumbar | Articular mobilisation (lumbar spine) | Ineffective mobilisation forces applied on lumbar spine | None | 2 weeks |
| Hoiriis, 200429 | 156 | ≥2,3 weeks | Lumbar | SM (spine) | Ineffective force applied on spine | Medical treatment | 4 weeks |
| Klein, 201337 | 61 | >1 month and <5 years | Cervical | Strain-counterstain techniques (cervical spine) | Ineffective force applied on cervical spine | None | No follow-up (outcomes collected after the intervention) |
| Kogure, 201545 | 179 | >12 months and <10 years | Lumbar | Arthrokinematic Approach-Hakata (AKA-H) (sacro-iliac joint) | Ineffective force applied on sacro-iliac joint | None | 6 months |
| Krekoukias, 201730 | 50 | Not reported | Lumbar | Articular mobilisation techniques (lumbar spine) | Hand contact with lumbar skin placement without any movement | Exercise plus Transcutaneous Electrical Nerve Stimulation (TENS) | 5 weeks |
| Lascurain-Aguirrebena, 201833 | 40 | Not reported | Cervical | Articular mobilisation (Cervical spine) | Ineffective force applied on cervical spine | None | No follow-up (outcomes collected after the intervention) |
| Licciardone, 200331 | 91 | ≥3 months | Lumbar | Osteopathic manual treatment (OMT) (all body) | Protocol of light touch techniques similar to OMT applied to all body | No treatment group | 6 months |
| Licciardone, 201324 | 455 | ≥3 months | Lumbar | OMT– (all body) | Protocol of light touch techniques similar to OMT applied to all body | None | 8 weeks |
| Pires, 201542 | 32 | >3 months | Cervical | SM (thoracic spine) | Ineffective force applied on thoracic spine | None | 72 hours |
| Quinn, 200839 | 15 | Not reported | Lumbar | Reflexology (foot) | Foot massage with less pressure and in different reflex point (not related to the spine) | None | 18 weeks |
| Selkow (2009)34 | 20 | 1–6 weeks | Lumbar | Muscular energy technique (anterior superior iliac spine and lower limbs) | Practitioner hand positioned as active treatment, but participant rested for 30 s without any active contraction | None | 24 hours |
| Senna, 201132 | 93 | ≥13 months | Lumbar | SM (lumbar spine) | Ineffective force applied on lumbar spine | Maintained SM | 10 months |
| Sillevis, 201040 | 100 | ≥23 months | Cervical | SM (thoracic spine) | Ineffective force applied on thoracic spine | None | No follow-up (outcomes collected after the intervention) |
| Silva, 201943 | 28 | >3 months | Cervical | Osteopathic visceral treatment (abdomen) | Hand contact on umbilical region without any movement | None | 7 days |
| Veira-Pellez, 201444 | 40 | Not reported | Lumbar | SM (lumbar/sacral spine) | Ineffective force applied on lumbar/sacral joints | None | No follow-up (outcomes collected after the intervention) |
| Younes, 201738 | 17 | <3 months | Lumbar | OMT (all spine) | Placebo mimed active treatment with an ineffective force applied. | None | 7 days |