Martin Descarreaux, Jean-Sébastien Blouin, Marc Drolet, Stanislas Papadimitriou, Normand Teasdale
Martin Descarreaux, DC,
Universite du Quebec a Trois-Rivières,
Department de chiropractique,
Bureau 3613, 3351 Boul.
Des Forges C.P. 500,
Trois-Rivières, Quebec G9A 5H7, Canada
OBJECTIVE: To document the potential role of maintenance chiropractic spinal manipulation to reduce overall pain and disability levels associated with chronic low-back conditions after an initial phase of intensive chiropractic treatments.
METHODS: Thirty patients with chronic nonspecific low-back pain were separated into 2 groups. The first group received 12 treatments in an intensive 1-month period but received no treatment in a subsequent 9-month period. For this group, a 4-week period preceding the initial phase of treatment was used as a control period to examine the sole effect of time on pain and disability levels. The second group received 12 treatments in an intensive 1-month period and also received maintenance spinal manipulation every 3 weeks for a 9-month follow-up period. Pain and disability levels were evaluated with a visual analog scale and a modified Oswestry questionnaire, respectively.
RESULTS: The 1-month control period did not modify the pain and disability levels. For both groups, the pain and disability levels decreased after the intensive phase of treatments. Both groups maintained their pain scores at levels similar to the postintensive treatments throughout the follow-up period. For the disability scores, however, only the group that was given spinal manipulations during the follow-up period maintained their postintensive treatment scores. The disability scores of the other group went back to their pretreatment levels.
CONCLUSIONS: Intensive spinal manipulation is effective for the treatment of chronic low back pain. This experiment suggests that maintenance spinal manipulations after intensive manipulative care may be beneficial to patients to maintain subjective postintensive treatment disability levels. Future studies, however, are needed to confirm the finding in a larger group of patients with chronic low-back pain.
From the Full-Text Article:
The present results show that no improvement in pain or disability scores was achieved through a 1-month control period where no intervention was provided. Moreover, this study confirms previous reports showing that pain and disability scores related to chronic LBP conditions are reduced after SMTs.  Stig et al  showed that 75% of the chronic LBP patients receiving chiropractic treatments reported improvements (pain and global improvement) after 12 visits. Meade et al  showed significant decrease of Oswestry scores after 10 chiropractic treatments (mainly manipulative treatment) in patients with chronic and severe LBP.
The main objective of this study was to evaluate the effects of preventive chiropractic treatments in maintaining functional capacities and levels of pain after an acute phase of treatment. Although the VAS pain scores remained at posttreatment levels for both groups, disability scores returned to their pretreatment levels for the LBP-1 group (no maintenance treatment), whereas they stayed at their posttreatment levels for the LBP-2 group (maintenance treatment group). The disability score difference (more than 15 points) observed between the 2 groups is not only statistically significant but also clinically important. Fritz and Irrgang  showed that a 6-point difference in the Modified Oswerstry Questionnaire was the minimal clinically important difference. This difference is defined as the amount of change that best distinguishes between patients who have improved and those who remained stable. Even if disabilities can be a consequence of chronic LBP, the relationship between pain and disability levels is not straightforward. [20, 21] There are at least 2 possible explanations for the discrepancies observed between pain and disability scores in the LBP-1 group. Patients from this group did use the ice significantly more often than the LBP-2 group. Even if the average pain scores were similar in both groups, it seems that patients from the LBP-1 group experienced a greater number of acute pain episodes. In a study aimed at defining the relation between pain intensity, disability, and episodic nature of chronic LBP, McGorry et al  showed that disability and medication use were strongly correlated to acute pain episodes. They concluded that “whereas pain intensity can have a profound effect on disability, the episodic nature of LBP also affects the patient’s ability to function in both work and personal life.” It is possible that the patients from this group (LBP-1 patients who presumably had more acute pain episodes) suffered from higher levels of disabilities, even if their average pain scores were still at a low level. On the other hand, the LBP-2 group could have experienced fewer acute pain episodes because of the maintenance SMT. Other factors like psychologic and social status could influence the evolution of pain and disability and should be included in further investigations.
Because of different factors, it is possible that the patients in the LBP-1 group overestimated their level of disabilities. In 2000, Al-Obaidi et al  proposed the hypothesis that spinal physical capacity in chronic LBP patients is not explained solely by the sensory perception of pain. They found that cognitive perception of pain, anticipation of pain, and fear-avoidance belief about physical activities were the strongest predictors of the isometric strength deficit in chronic LBP patients. In their experiment, the intensity of true pain experienced during the isometric strength test and the self-reported disability belief were not related to the spinal strength deficit. Because the LBP-1 group had more acute pain episodes during the 9 months after the first phase of treatment, it is a possibility that they perceived themselves more disabled than they really were. Future study will be needed to include a “fear avoidance belief questionnaire” to clarify this question.
Alternatively, it is plausible that, as frequently encountered in practice, the patients from the LBP-2 group did benefit from the maintenance treatments. Many chiropractors believe that periodic patient visits permit the detection and early treatment of joint dysfunction, thus preventing future episodes of LBP. Physical improvements such as improved trunk mobility  or prevention through the proposed mechanisms of SMT-like release of entrapped synovial folds or plica, relaxation of hypertonic muscle by sudden stretching, or disruption of articular or periarticular adhesions may explain the observed differences between the 2 groups. 
This study appears to confirm previous reports showing that LBP and disability scores are reduced after spinal manipulation.  It also shows the positive effects of preventive chiropractic treatment in maintaining functional capacities and reducing the number and intensity of pain episodes after an acute phase of treatment. Maintenance chiropractic care involving spinal manipulation combined with other treatment modalities (exercises, pain management program) should be investigated. Such combined interventions may have a critical influence on pain, disability, and return to work.