An investigation of implicit bias about bending and lifting

Previous studies in a high-income country have demonstrated that people with and without low back pain (LBP) have an implicit bias that bending and lifting with a flexed lumbar spine is dangerous. These studies present two key limitations: use of a single group per study; people who recovered from back pain were not studied. Our aims were to evaluate: implicit biases between back posture and safety related to bending and lifting in people who are pain-free, have a history of LBP or have current LBP in a middle-income country, and to explore correlations between implicit and explicit measures within groups.

Exploratory cross-sectional study including 174 participants (63 pain-free, 57 with history of LBP and 54 with current LBP). Implicit biases between back posture and safety related to bending and lifting were assessed with the Implicit Association Test (IAT). Participants completed paper-based (Bending Safety Belief [BSB]) and online questionnaires (Tampa Scale of Kinesiophobia; Back Pain Attitudes Questionnaire).

Participants displayed significant implicit bias between images of round-back bending and lifting and words representing "danger" (IAT_D-SCORE: Pain-free group: 0.56 (IQR=0.31-0.91; 95% CI [0.47, 0.68]); history of LBP group: 0.57 (IQR=0.34-0.84; 95% CI [0.47, 0.67]); current LBP group: 0.56 (IQR=0.24-0.80; 95% CI [0.39, 0.64])). Explicit measures revealed participants hold unhelpful beliefs about the back, perceiving round-back bending and lifting as dangerous (BSB_thermometer: Pain-free group: 8 (IQR=7-10; 95% CI [7.5, 8.5]); history of LBP group: 8 (IQR=7-10; 95% CI [7.5, 9.0]); current LBP group: 8.5 (IQR=6.75-10; [7.5, 9.0])). There was no correlation between implicit and explicit measures within the groups.

In a middle-income country, people with and without LBP, and those who recovered from LBP have an implicit bias that round-back bending and lifting is dangerous.