It has been clarified that a worker with low back pain has a narrow range of motion of the trunk and a decrease in the movement speed of the trunk (becomes slow) during work operations such as lifting a heavy object.Such trunk dyskinesia can be thought of as "excessive protective behavior to avoid pain," but it is unclear how various pain-related factors are involved in causing dyskinesia. was.

　Therefore, Mr. Ren Fujii and Professor Shu Morioka of the doctoral course at Kio University graduate school asked workers without back pain and workers with back pain to participate in the experiment and lift heavy objects using a three-dimensional motion analysis device. By measuring the trunk movement at the time and evaluating pain-related factors such as "exercise fear", "catastrophic thinking", and "anxiety" using a questionnaire, the relationship between movement abnormalities and pain-related factors can be detailed. Was analyzed.

　As a result, low back pain slowed down the stretching movement of the trunk when lifting heavy objects.And the pain-related factor that influences slowness was found by mediation analysis to be "fear of exercise caused by past pain experiences."In other words, the slowdown in the movement speed of the trunk when lifting heavy objects is not caused by the pain that occurs during movement, but by the exercise fear caused by the experience of pain that has occurred in the past.

　If there is no pain during work, but the movement disorder of the trunk appears due to exercise fear, it is considered to be a factor that eventually leads to chronic pain.In the future, the group plans to examine the possibility that interventions that reduce exercise fear may improve movement disorders.

Paper information:[PLOS ONE] Kinematic analysis of movement impaired by generalization of fear of movement-related pain in workers with low back pain