Isoinertial functional assessment of low-back disorders in pediatric nurses: Ergonomic and rehabilitation guidelines

Low-back troubles are among the most common and most disabling occupational pathologies. It is very common in health professionals including pediatric nursing personnel. However, the problem is difficult to assess, as in many cases there is no objective origin for the complaints. Therefore, objective measures of function are of great interest. Trunk function in a population of 50 pediatric nurses was investigated with an isoinertial dynamometric device (Isostation B200). Isometric torques, unresisted ranges of motion and dynamic velocities were measured in the sagittal plane. The population was divided into three groups: those subjects with no complaints (LBP0) those with moderate low-back pain (LBP1), and those with severe low-back pain (LBP2). Forty-two (85%) of those nurses had low-back complaints, 31 moderate and 11 severe. Isometric torques and velocities enabled a good discrimination between the three groups. There were significant differences between nurses usually carrying children on right or left arm and those carrying indifferently on any arm. The latter had better performances and less low-back pain. The velocity extension to flexion ratio was significantly decreased with the existence and severity of low-back pain. Isoinertial functional assessment has a good discriminatory value in this population. It enables one to draw ergonomic guidelines for child-carrying techniques. Finally, the modifications of the extension to flexion ratio help to determine that, in this population, rehabilitation programs should focus on dynamic back muscle strengthening.