Predictors of pain intensity and Oswestry disability index in prolonged standing service workers with nonspecific chronic low back pain that sub-classified active extension pattern

To investigate which psychological, postural, mobility, and strength variables contributed most significantly to the degree of low back pain and dysfunction, multiple regression models with a stepwise selection procedure were performed for the 14 independent variables, with visual analogue scale (VAS) and dysfunction as the dependent variable. The determination coefficient (R2) showed the explanatory power for models of regression variables in multiple regression with a stepwise selection procedure. Stepwise multiple-regression analyses were performed to identify variables that contributed significantly to VAS in prolonged standing service workers with non-specific low back pain for active extension pattern. In the stepwise regression analyses, model 5 included hip abductor strength, lumbopelvic stability, pelvic anterior tilting angle, job stress, and hip extension range of motion as predictor variables and accounted for 40.1% of the variance in VAS. For disability, model 2 included hip external rotator strength and age as predictor variables and accounted for 11.9% of the variance in Oswestry disability index (ODI). According to the independent variables, the regression equations were set up using slope and constant values in unstandardized coefficients. The VAS was computed using the regression equation. In ß values, as standardized coefficients of model 5, the following were independent influencing variables on VAS: hip abductor strength (ß =-0.321), lumbopelvic stability (ß =-0.166), pelvic anterior tilting angle (ß =0.241), job stress (ß = 0.199), and hip extension ROM (ß =-0.196). In independent influencing variables on ODI, ß values were hip external rotator strength (ß =-0.300) and age (ß =0.243).