J Canadian Chiropractic Association 2026 (Apr); 70 (1): 27-54

Table 4.

Individual study results.

Author and Year Condition Intervention group(s) with SMT Comparison group(s) without SMT Between-group effect estimate(s) for spine related pain and physical function, QoL, or ADLs outcomes Between-group findings and interpretation
Learman 2013 Low back pain TM+HEP Non-TM+HEP Not reported No significant between-group differences for pain or disability (p=.99)
Dougherty 2014 Low back pain SMT Sham (detuned ultrasound) VAS (MD w/95% CI)

  • 5 weeks: 5.87 [−2.78, 14.52] (F=1.87, p=0.17)

  • 12 weeks: 5.61 [−3.12, 14.34] (F=1.68, p=0.19)

ODI (MD w/95% CI)

  • 5 weeks: 2.03 [−2.3, 6.3] (F=1.19, p=0.27)

  • 12 weeks: 5.25 [1.24, 9.26] (F=6.95, p<0.001)

SF-36 PFS (MD w/95% CI)

  • 5 weeks: 0.04 [−0.08, 0.16] (F=.42, p=0.52)

  • 12 weeks: 0.07 [−0.06, 0.20] (F=1.01, p=0.31)

 No significant between-group differences for VAS and ODI at 5 weeks, or for VAS at 12 weeks. Statistically significant difference at 12 weeks with SMT showing a greater reduction in ODI (p<.001), but not clinically meaningful. Secondary analyses demonstrate a nonspecific therapeutic effect of the intervention.
Enix 2015 Balance problems and low back pain SMT+soft tissue manipulation Multimodal physical therapy exercise, without SMT Pain values (all measures)

  • No significant between-group effects at 6 or 12 weeks for pain (all p-values >0.05)

Usual pain (MD w/95% CI)

  • 6 weeks: 0.4 [−5.91, 6.71]

  • 12 weeks: −1.55 [−8.49, 5.39]

 Statistically and clinically significant improvements in pain outcome measures in both the chiropractic care and physical therapy treatment groups at week 6 and at week 12, however there were no significant between-group effects at 6 or 12 weeks for pain.
Maiers 2014 Neck pain SMT+HE SRE+HEA and HEA alone Pain MD at 12 weeks (MD w/95% CI)

  • SMT+HEA vs. SRE+HEA: −0.55 [−1.10, 0.00] (p≤0.05)

  • SMT+HEA vs. HEA: −1.04 [−1.59, −0.49] (p≤0.01)

NDI at 12 weeks (MD w/95% CI)

  • SMT+HEA vs. SRE+HEA: −0.27 [−2.55, 2.02] (p >0.05)

  • SMT+HEA vs. HEA: −1.59 [−3.90, 0.73] (p >0.05)

SF-36 PFS at 12 weeks (MD w/95% CI)

  • SMT+HEA vs. SRE+HEA: −0.14 [−1.75, 1.46] (p>0.05)

  • SMT+HEA vs. HEA: −0.27 [−1.91, 1.36] (p>0.05)

 SMT+HEA yielded greater pain reduction after 12 weeks of treatment compared to both SRE+HEA and HEA alone. There were no statistically significant between-group differences in disability.
Maiers 2019 Neck and back disability SMT+ supervised exercise (12 weeks) SMT+ supervised exercise (36 weeks) NDI at 36 weeks (MD w/95% CI)

  • 1.7 [−0.8, 4.2] (p=0.18)

ODI at 36 weeks (MD w/95% CI)

  • 2.4 [−0.3, 5.1] (p=0.08)

Neck pain at 36 weeks (MD w/95% CI)

  • 0.7 [0.1, 1.2] (p=0.02)

Low back pain at 36 weeks (MD w/95% CI)

  • 0.4 [−0.2, 1.0] (p=0.19)

EQ at 36 weeks (MD w/95% CI)

  • 0.0 [−0.0, 0.0] (p=0.72)

SPPB at 37 weeks (MD w/95% CI)

  • −0.5 [−1.0, −0.0] (p=0.04)

 There were no significant between-group differences for ODI, NDI, or medication use at 36 weeks’ follow-up. However, there were statistically significant differences in favor of long-term management for self-reported improvement in neck pain, as well as functional measures.
Schneider 2019 Lumbar spinal stenosis MT/IE Medical Care alone and Group-based exercise alone SSS at 2 months (MD w/95% CI)

  • MT/IE vs. medical care: −2.0 [−3.6, −0.4] (p<0.05)

  • MT/IE vs. group exercise: −2.4 [−4.1, −0.8] (p<0.05)

SPWT at 2 months (MD w/95% CI)

  • MT/IE vs. medical care: 122.9 [−25.7, 271.6]

  • MT/IE vs. group exercise: 43.0 [−111.8, 197.9]

 MT/IE yielded a greater reduction in SSS score compared to medical care, and group exercise, yet did not reach a minimal clinically important difference of 3.02 points. There was no meaningful difference in SPWT, with comparisons of MT/IE vs. medical, and MT/IE vs. general exercise.
Schulz 2019 Low back pain SMT+HEP SEP+HEP and HEP alone Short Term Pain at weeks 4 to 12 (MD w/95% CI)

  • SMT+HEP minus HEP: −0.48 [−1.00, 0.03]

Long term pain at weeks 4 to 52 (MD w/95% CI)

  • SMT+HEP minus HEP: −0.13 [−0.59, 0.34]

Short-term MRS at weeks 4 to 12 (MD w/95% CI)

  • SMT+HEP minus HEP: 0.78 [−3.99, 5.54]

Long-term MRS at weeks 4 to 52 (MD w/95% CI)

  • SMT+HEP minus HEP: −1.42 [−5.88, 3.04]

Short-term SF-36 PFS at weeks 4 to 12 (MD w/95% CI)

  • SMT+HEP minus HEP: 0.56 [−1.09, 2.21]

Long-term SF-36 PFS at weeks 4 to 52 (MD w/95% CI)

  • SMT+HEP minus HEP: −0.34 [−1.87, 1.2]

 Adding SMT to HEP alone did not significantly improve pain or disability outcomes in the short-or long-term. There were no significant or meaningful between-group differences with respect to pain, Modified Roland Scale, or SF-36 PFS.

Abbreviations:

CI, Confidence Intervals;
EQ, EuroQol EQ-5D;
HEA, Home Exercise and Advice;
HEP, Home Exercise Program;
MD, mean difference;
MRS, Modified Roland Scale;
MT/IE, Manual Therapy/Individualized Exercise;
NA, not applicable/present;
NDI, Neck Disability Index;
NPRS, Numeric Pain Rating Scale;
ODI, Oswestry Disability Index;
OR, Odds Ratio;
PFS, Physical Function Subscale;
QALY, Quality-Adjusted Life Year;
SF-36, 36-Item Short Form Survey;
SPPB, Short Physical Performance Battery;
SPWT, Self-Paced Walking Test;
SRE, Supervised Rehabilitative Exercise;
SMT, Spinal Manipulative Therapy;
SSS, Swiss Spinal Stenosis Questionnaire;
TM, Thrust Manipulation;
VAS, Visual Analog Scale.