Effects of obesity and chronic low back pain on gait

Background: Obesity is often associated with low back pain (LBP). Despite empirical evidence that LBP induces gait abnormalities, there is a lack of quantitative analysis of the combined effect of obesity and LBP on gait. The aim of our study was to quantify the gait pattern of obese subjects with and without LBP and normal-mass controls by using Gait Analysis (GA), in order to investigate the cumulative effects of obesity and LBP on gait. Methods: Eight obese females with chronic LBP (OLG; age: 40.5 +/- 10.1 years; BMI: 42.39 +/- 5.47 Kg/m(2)), 10 obese females (OG; age: 33.6 +/- 5.2 years; BMI: 39.26 +/- 2.39 Kg/m(2)) and 10 healthy female subjects (CG; age: 33.4 +/- 9.6 years; BMI: 22.8 +/- 3.2 Kg/m(2)), were enrolled in this study and assessed with video recording and GA. Results and Discussion: OLG showed longer stance duration and shorter step length when compared to OG and CG. They also had a low pelvis and hip ROM on the frontal plane, a low knee flexion in the swing phase and knee range of motion, a low dorsiflexion in stance and swing as compared to OG. No statistically significant differences were found in ankle power generation at push-off between OLG and OG, which appeared lower if compared to CG. At hip level, both OLG and OG exhibited high power generation levels during stance, with OLG showing the highest values. Conclusions: Our results demonstrated that the association of obesity and LBP affects more the gait pattern than obesity alone. OLG were in fact characterised by an altered knee and ankle strategy during gait as compared to OG and CG. These elements may help optimizing rehabilitation planning and treatment in these patients.