Analisis terhadap load constant (LC) dalam revised niosh lifting equation

MUSLIMAH, Etika, Ir. Subagyo, Ph.D

2008 | Tesis | S2 Teknik Mesin

Revised NIOSH Lifting Equation adalah salah satu metode untuk menganalisis pekerjaan Manual Material Handling (MMH). Persamaan ini menentukan Recommended Weight Limit (RWL) yaitu batas beban maksimal yang aman untuk diangkat. Persamaan ini terdlri dari 1 konstanta pembebanan (Load Constant) dan 6 faktor posisi pengangkatan. Faktor-faktor yang sudah pemah diteliti dengan subyek orang Indonesia adalah faktor vertical, jarak, asimetri dan frekuensi. Secara umum ukuran yang dihasilkan dari penelitian tersebut lebih kecil dari ukuran yang ditentukan NIOSH. Tujuan utama penelitian ini adalah untuk menganalisis Load Constant dari Revised NIOSH Equation dengan menggunakan antropometri orang Indonesia. Kedua, mengetahui pengaruh arah pengangkatan (aktivitas lifting dan lowering) terhadap Load Constant. LC dalam penelitian ini ditentukan berdasarkan tiga kriteria yaitu psikofisik, fisiologi dan biomekanika. Kriteria psikofisik untuk memastikan bahwa beban dapat diterima oleh 75 % pekeija wanita dan 99% pekerja pria. Kriteria fisiologi membatasi energy expenditure maksimal antara 2,2 - 4,7 kkl/menit. Sedangkan kriteria biomekanika membatasi gaya tekan di L5/S1 kurang dari 3,4 kN. Hasilnya adalah load constant untuk lifting adalah 18,7 kg dan untuk lowering adalah 19,64 kg. Beban pada aktifitas lowering lebih besar daripada lifting. Arah pengan^atan berpengaruh terhadap load constant Kedua beban tersebut masih lebin kecil yang ditetapkan NIOSH yaitu 23 kg. Kata kunci: MMH, NIOSH, lifting, lowering, load constant

Revised NIOSH Lifting Equation is one of the methods applied to analyze Manual Material Handling (MMH). The equation is applied to determine the Recommended Weight Limit (RWL) for safe lifting tasks. It consists of load constant (LC) and six lifting factors (multipliers). The factors are horizontal, vertical, distance, asymmetric, frequency, and coupling multipliers. The factors that have been analyzed by taking Indonesians as the subject of the research are vertical, distance, asymmetric, and frequency factors. Generally, the size resulted from these researches is less than that determined by NIOSH. The main objective of this study was to determine Load Constant (LC) from Revised NIOSH Equation by taking Indonesians anthropometry based on psychophysical, physiological, and biomechanical criteria. The secondaiy objective was to identify the effect of lifting and lowering angle on LC LC in this research is based on three criterias : psychophysics, physiology and biomechanics. The psychophysical criterion was selected to ensure that the lifting demands would not exceed the acceptable lifting capacity of about 75 percent of female workers and 99 percent of male workers. The physiological criterion sets the limit of maximum energy expenditure for lifting task at 2.2 to 4.7 kcal/min. The biomechanical criterion selects 3,4 kN as the compressive force t the L5/S1 disc that defines an increased risk of low back pain. The result of the research are the Load Constant is 18.7 kgs for lifting task and 19.64 kgs for lowering task, which demonstrates that lifting angle also brings influence on load constant. It shows that load weight in lowering task is higher than that in lifting task. Both loads are lower than those determined by NIOSH, which is 23 kgs. Keyword: MMH, NIOSH, lifting, lowering, and Load Constant

Kata Kunci : Manual material handling, NIOSH, Lifting equation, Load constant