Evaluation of four weight transfer devices for reducing loads on the lower back during agricultural stoop labor

摘要

Low back disorders (LBDs) in agricultural settings are one of the most prevalent and costly occupational disorders. LBDs are particularly prevalent in manual harvesting, which is still a major method used in harvesting a wide range of fruits, vegetables and other crops. In most instances, this method requires the worker to assume a stooped posture for prolonged periods, which has been identified as an important risk factor for developing occupational LBDs. Several devices have been developed in anattempt to reduce the likelihood for developing LBDs during stooped labor. All these devices, using various mechanical means, share the same design principle of transferring the loads imposed on the lower back to the hips and lower limbs. The purpose ofthis study was to quantitatively assess the effectiveness of four commercially available devices in reducing the loads on the spine under assumed stooped postures. The results indicated that all four devices reduced trunk muscle activities to varying degrees. Two of the devices generated increased activities in the knee flexor muscle. The practicality for field use of three out of the four devices also was assessed. Overall, the concept of personal weight transfer devices offers an approach that is worth pursuing in the effort to prevent LBDs due to agricultural stoop labor.