Enggrong Modification Reduces Low Back Pain Risk on Sand Workers

Material handling manual work is a job at risk to worker health and safety, errors in the manual procedure of manual material handling will result in health impacts in the short and long term. One of the manual jobs of material handling is the job of lowering the sand from the top of the truck. In working the workers use a tool in the form of enggrong which is a shovel with a short handle. Due to the use of employee enggrong work with a stooped posture. This work posture raises the potential for low back pain on workers. Low back pain is a pain and/or loss of workability as a long-term risk of postural errors in activity. Low back pain occurs on low back disc L4 / L5 or L5 / S1. This study used treatment by the same subject design with a sample of 9 participants. The purpose of the study was to find out the different forces in Low back disc L4 / L5 when the worker worked using standard enggrong (Period 1 / P1) compared to using modification enggorong (Period 2 / P2). The forces in the L4 / L5 Low back disc include 1) compression, 2) anterior/posterior shear, and 3) lateral shear. Work posture data was taken using Microsoft KinectTM 3D camera and analyzed by using Siemen Jack 3D Static Strength Prediction Program (3DSSPP) method to get the force on the low back disc. The results of the analysis of the 6 work postures P1 and P2, showed a significant decrease (p <0.05) in the average compression force in the low back disc L4 / L5 on the work posture using modified enggrong. Enggrong modification lowers compression in low back disc L4 / L5 by 38.73% (P1 2143.8 ± 411.3 N; P2 1320.2 ± 418.4 N), anterior / posterior shear 46.17% (P1 542, 6 ± 103.9 N, P2 292.1 ± 81.2 N), and lateral shear 29.69% (P1 31.2 ± 22.08 N; P2 16.6 ± 14.28 N) compared with the use of enggrong standard. The threshold value for compression 3400 N and anterior / posterior shear is 700 N, then the compression and anterior / posterior shear values in Period 2 are well below the threshold. Decrease in the press force in low back disc L4 / L5 is as a result of changes in work posture workers who work using modification enggrong. It can be concluded that the use of modification enggrong can decrease the compressive force in the low back disc L4 / L5 so as to reduce the low back pain occurs to the workers.