The Effects of Patients BMI on Lumbo Pelvic Parameters in Patients with Chronic Low Back Pain in Jos North Central Nigeria

Abstract

Introduction. The pelvic posture is defined by measurable radiologic parameters which are related to the lumbar and sacral spine. These parameters include, pelvic tilt (PT), lumbar Lordosis (LL), Sacral slope (SS), Pelvic incidence (PI) and the Lumbosacral angle (LSA) The lumbopelvic parameters in the lower back have been noticed to be altered in patients presenting with low back pain. Increased BMI has been found to be a contributing factor in the onset and course of low back pain. Increased weight especially around the trunk affects the dynamics of posturing to maintain sagittal balance. We set out to determine the extent BMI influenced the lumbopelvic parameters in patients presenting with chronic nonspecific low back pain. Methods. This was a prospective cross sectional study. There were three BMI groups; normal weight (BMI19-24.9), overweight (BMI 25-29.9) and obese (BMI>30). All subjects had standing lateral radiographs of the spine. The pelvic parameters; PI, LL PT, SS and LSA, were measured. The mean values and standard deviations of the parameters in each group was determined. Analysis of variance was used to determine differences in means The relationships between all parameters were assessed using Spearman’s coefficients and statistically significant correlation coefficients were determined. The level of significance was set at P<0.05Results. A hundred and forty patients participated in the study. Their ages ranged from 18 to 65years. M:F 1:1.1. 31 (22.1%) of them were of normal weight, 55 (39.3%) of them were overweight, and 54 (38.6%) were obese. None was underweight. The sacral slope was; 34.29±6.29 in the normal weight group, 36.20±5.97 in those overweight and 37.81±5.98 in the obese. (P=0.036). Pelvic incidence was: 51.19±6.35 in the normal weight group, 52.55±7.37 in those overweight and 54.43±9.23 in the obese (P=0.176). Lumbar lordosis was; 40.48±8.16 in the normal weight group, 40.35±8.06 in those overweight and 43.17±10.92 in the obese (P=0.032). The pelvic tilt was; 16.84±5.33 in the normal weight group, 16.29±3.54 in those overweight and 16.61±5.20 in the obese. (P=0.862). The Lumbosacral Angle was 12.74±3.14 in the normal weight group, 13.45±3.79 in those overweight and 12.98±3.55 in the obese. (P=0.634) Conclusion. Increasing BMI had a statistically significant effect on increased lumbar lordosis and sacral slope in patients with chronic low back pain. Pelvic Incidence showed an increase with increasing BMI but was not statistically significant. Pelvic tilt and lumbosacral angle did not show any relationship with BMI.