Risk Factors, Pragmatic Lifting Advice and the Truth About Sitting

Evidence that heavy work, bent postures or manual handling cause low back pain is conflicting, with no clear dose-response relationship, and a twin study found occupational exposure did not predict disc pathology or pain. Psychosocial factors such as low job satisfaction, poor social support, low decision latitude and monotonous work carry more weight. Cumulative load around 25 kilograms lifted 25 times a day may raise risk, though that research did not address posture or psychosocial factors. Peter O'Sullivan's model of interacting factors helps explain why the same lift hurts one day and not another. The speaker's pragmatic advice is that light loads can be lifted any way, while near the higher threshold people can avoid end range, move at moderate speed and keep loads close. Unaccustomed load, rather than heavy load, is the useful idea for new or returning workers. Education should be paired with exercise, as ergonomic interventions appear ineffective. Sitting is not inherently harmful. Moving often, activity outside work and positive messages about the spine are recommended.