Obesity Is Associated With Lumbar Pain Related Fear Of Movement And Self Reported Mobility Impairment

Abstract

Chronic low back pain (LBP) induces mobility impairment and disability. Obesity is a risk factor for LBP and disability. Pain evokes fear avoidance beliefs and behaviors, thereby worsening LBP. It is unknown whether obesity is associated with fear of movement. PURPOSE: The purposes of this study were: 1) to compare the levels of fear of movement between obese and non-obese individuals seeking therapy for chronic LBP, and 2) to examine whether fear of movement predicted self-reported mobility impairment. METHODS: This was a retrospective, exploratory study of individuals with chronic LBP (N = 192; 48.2±18.8 yrs). Participants were stratified into obese (Body mass index [BMI]36.9±7.1 kg/m2) or non-obese groups (BMI 24.5±3.4 kg/m2). The Tampa scale of Kinesiophobia (TSK; fear of movement), Short-Form 8 (SF8) and Oswestry Disability survey results were main outcome measures. Self-reported medication use and participation in exercise therapy sessions for LBP were collected. Outcome comparisons were made using univariate analyses of variance. Hierarchal regression modeling was used to determine the contribution of TSK scores to the variance of self-reported disability with walking. RESULTS: TSK scores in obese patients were higher than in non-obese patients (26.2±7.5 vs 23.9±6.8 points; p = 0.032). The SF8 physical and mental subscores were 6-10% lower in the obese than non-obese patients. Total Oswestry survey scores were 28% higher in the obese patients prior to the exercise therapy program (p = 0.0001). Hierarchal regression modeling showed that fear of exercise was a significant contributor to self-reported disability with walking (p<0.0001). Narcotic use was higher (32.4 vs 17.2%) and non-steroidal anti-inflammatory medication use was lower (18.6 vs 34.9%) in the obese than non-obese group (p<0.05). Obese patients cancelled therapy sessions twice as frequently than non-obese patients (p = 0.012). CONCLUSIONS: Obesity-related fear of movement is an important predictor of disability and participation in exercise therapy for chronic LBP. In addition to traditional exercise therapy protocols to combat LBP in obesity, adjunctive psychosocial strategies should be a serious consideration.