There has been a large body of research comparing overall effectiveness of instrument versus manual adjusting for overall treatment of musculoskeletal disorders.
Much of this research has found instrument adjusting superior to manual adjusting, in terms of delivering more force over a smaller area, as well as less wear and tear on the chiropractor. Instrument adjusting is also more effective than manual adjusting for geriatric and pediatric patients, as well as for those with osteoporosis or other conditions with fragile bones. However, there is far less research comparing the two chiropractic adjusting techniques for treating specific musculoskeletal disorders.
A group of researchers recently published a meta-analysis article in the March 2012 issue of the Journal of the Canadian Chiropractic Association to compare the use of instrument adjusting versus high-velocity, low-amplitude (HVLA) manual adjusting to treat a variety of specific musculoskeletal disorders. A meta-analysis study examines the findings of other papers published on a specific topic to look for similarities and patterns across the results. The advantage to this analysis is that it can show greater strength for the results across several papers.
The researchers first conducted a literature search to find peer-reviewed papers that compared instrument adjusting to HVLA in terms of clinical effectiveness. The papers had to include some sort of outcome measure, such as the Visual Analogue Scale (VAS), Numerical Pain Rating Scale (NPRS), Neck Disability Index (NDI), Oswestry Disability Index (ODI), McGill Pain Questionnaire, range of motion, or use of algometer/goniometer devices. Manuscripts based on conference proceedings were not included, as the criteria for inclusion in conference proceedings is not as stringent as that for peer-reviewed journals.
The researchers narrowed their search down to a total of eight papers, covering 92 patients. These papers met the inclusion/exclusion criteria for the meta-analysis. These papers covered a variety of specific conditions, such as acute and chronic low back or sacroiliac joint pain, acute and sub-acute neck pain, temporomandibular joint disorders, and trigger points in the trapezius muscle. In all the papers, instrument adjusting was found to have clinically more meaningful benefits for these conditions than did HVLA.
The researchers concluded: “Further studies ought to include a larger patient base using a placebo or sham group and a no-treatment group, better randomization and blinding protocols and longer-term post-intervention follow-up in order to more definitively assess the benefits of…treatment.”