INFLUENCE OF PROLONGED SITTING POSTURE ON TRUNK REGULARITY IN PEOPLE WITH CHRONIC LOW BACK PAIN
Keywords: multiscale entropy; low back pain; regularity; motor control; nonlinear dynamics
Low back pain is the most disabling musculoskeletal condition and the leading cause of years lived with disability in populations around the world. It is responsible for large expenditures on public health, absence from work and compulsory retirement. One of the most studied associations in literature is the relationship between low back pain and prolonged sitting. It is estimated that prolonged sitting posture is a risk factor for low back pain and an aggravating factor for people who already have low back pain. Studies with linear biomechanics investigated the kinematics of sitting posture and its relationship with low back pain. In general, studies have shown a low correlation between high and low lumbar angles of movement with low back pain in static postures and functional activities. The use of linear biomechanical variables, despite being traditional, has received criticism because they do not consider the complex nature of movement, assuming, above all, a reductionist view of human movement. In contrast to linear methods, non-linear methods allow investigating aspects of movement complexity. Time series of biomechanical variables are obtained to determine, for example, the self-similarity of a signal. That is, the self-similarity between spatial and temporal scales of a time series. The entropy analysis has been used to estimate, in a quantitative way, the regularity of the behavior of a variable in the study of the human movement pattern. Objective: To investigate the association of prolonged sitting posture in trunk movements regularity in people with non-specific chronic low back pain who perform their work activities with a purely administrative function