Sagittal lumbopelvic alignment in patients with low back pain and the effects of a high-load lifting exercise and individualized low-load motor control exercises—a randomized controlled trial

Abstract Background Context Assessment of posture and lumbopelvic alignment is often the main focus in the classification and treatment of patients with low back pain (LBP). However, little is known regarding the effects of motor control interventions on objective measures of lumbopelvic alignment. Purpose The primary aim of this study was to describe the variation of sagittal lumbopelvic alignment in patients with nociceptive mechanical LBP. The secondary aim was to compare the effects of a high-load lifting exercise (HLL) and low-load motor control exercises (LMC) on the change in lumbopelvic alignment with a special emphasis on patients with high and low degrees of lumbar lordosis (lu) and sacral angle (sa). Study Design This study is a secondary analysis of a randomized controlled trial evaluating the effects of HLL and LMC. Patient Sample Patients from the primary study, that is, patients categorized with nociceptive mechanical LBP, who agreed to participate in the radiographic examination were included (n=66). Outcome Measures Lateral plain radiographic images were used to evaluate lumbopelvic alignment regarding the lumbar lordosis and the sacral angle as outcomes, with posterior bend as an explanatory variable. Materials and Methods The participants were recruited to the study from two occupational health-care facilities. They were randomized to either the HLL or the LMC intervention group and offered 12 supervised exercise sessions. Outcome measures were collected at baseline and following the end of intervention period 2 months after baseline. Between- and within-group analyses of intervention groups and subgroups based on the distribution of the baseline values for the lumbar lordosis and the sacral angle, respectively (LOW, MID, and HIGH), were performed using both parametric and non-parametric statistics. Results The ranges of values for the present sample were 26.9–91.6° (M=59.0°, standard deviation [SD]=11.5°) for the lumbar lordosis and 18.2–72.1° (M=42.0°, SD=9.6°) for the sacral angle. There were no significant differences between the intervention groups in the percent change of eitheroutcome measure. Neither did any outcome change significantly over time within the intervention groups. In the subgroups, based on the distribution of respective baseline values, LOW lu showed a significantly increased lumbar lordosis, whereas HIGH sa showed a significantly decreased sacral angle following intervention. Conclusions This study describes the wide distribution of values for lumbopelvic alignment for patients with nociceptive mechanical LBP. Further research is needed to investigate subgroups of other types of LBP and contrast findings to those presented in this study. Our results also suggest that retraining of the lumbopelvic alignment could be possible for patients with LBP.