Physical and Social Factors Differentiating Acute and Chronic Low Back Pain Among Small- and Medium-Sized Enterprise Workers in Japan: A Cross-Sectional Study

Low back pain is common and negatively impacts quality of life and workplace productivity. However, few studies have focused on small- and medium-sized enterprises (SMEs) where risk factors are prevalent. This cross-sectional study examined the association and structural relationships between physical and social factors in low back pain among Japanese SME workers. We analyzed survey data collected between April 2021 and August 2022 from 762 SME workers aged 18-65 years in Shimane, Japan, to assess acute (less than 3 months) and chronic low back pain using a self-reported questionnaire. Workplace physical (physical load) and social (stress of interpersonal relations) factors were measured using a brief job stress-related questionnaire. Associations between workplace factors and acute and chronic low back pain were evaluated using multivariable, multinomial logistic regression. Among the 762 workers, 50.9% and 7.3% reported acute and chronic low back pain, respectively. The odds ratio (OR) for acute pain was 2.08 for 'Very much so' in those with a high physical load. Compared with those with low interpersonal stress, the OR for chronic pain was 2.20 for medium stress and 2.82 for high stress. Reducing physical workloads may mitigate acute low back pain, while lowering interpersonal stress at work may reduce chronic low back pain. Future studies should investigate whether improving workplace physical and social factors is longitudinally effective.