Study Design Prospective cohort, test-retest design. Background DP/CEN and DP/non-CEN are common pain pattern responses assessed by Mechanical Diagnosis & Therapy (MDT). Although there is evidence that MDT can reduce pain and disability in the short term by treating the patient with direction-specific exercises concordant with the patient's DP, the mechanism responsible for this is unclear. Objective To determine if clinical signs of impaired spinal control improve immediately after eliciting a directional preference with centralization response (DP/CEN), or a directional preference without centralization response (DP/non-CEN), in patients with nonspecific low back pain (LBP). Methods Participants underwent a standardized MDT assessment and were classified in a pain pattern subgroup; DP/CEN, DP/non-CEN, or no-DP. Clinical signs of impaired spinal control were assessed pre- and post-MDT assessment by an independent examiner. Four spinal control tests were conducted: aberrant lumbar movements while bending forward, the active straight leg raise (ASLR) test, the Trendelenburg test and the prone instability test. Differences in spinal control pre- and post-MDT assessment were calculated for the three pain pattern subgroups and compared with Chi-square tests. We hypothesized that a larger proportion of patients in the DP/CEN subgroup would improve on spinal control than patients categorized as DP/non-CEN or no-DP. Results Of 114 patients recruited, 51 patients (44.7%) were categorized as DP/CEN, 23 (20.2%) as DP/non-CEN, and 40 (35.1%) as no-DP. Before MDT assessment between 28.9% (Trendelenburg test) and 63.7% (ASLR test) of patients showed impaired spinal control. After MDT assessment a larger proportion of patients in the DP/CEN subgroup (43%) showed improvement than those in the no-DP subgroup (7%) on aberrant lumbar movements (P = .02). Likewise, more patients in the DP/CEN subgroup (50%) improved on the ASLR test than in the no-DP subgroup (8%, P < .01) or the DP/non-CEN subgroup (7%, P = .01). Changes in Trendelenberg and prone instability tests did not reach statistical significance. Conclusions Immediately following MDT assessment, a larger proportion of patients with a DP/CEN pain pattern showed improvement in clinical signs of spinal control compared to patients with a DP/non-CEN or no-DP pain pattern. Level of Evidence 2b. J Orthop Sports Phys Ther, Epub 26 Jan 2016. doi:10.2519/jospt.2016.6158.
a1938-1344 (Electronic)