Musculoskeletal disorders (MSD) risks in forestry: a case study to propose an analysis method

Musculoskeletal disorders (MSDs) are amongst the most common work-related problem in Europe. In forestry yards we find all the conditions which expose workers to MSD risks: hard environmental conditions (low temperatures, slippery and uneven ground), heavy works (manual handling of loads, back flexed and twisted) and dangerous tools and machineries such as chainsaws. The high manual work load can therefore cause MSDs amongst the loggers. This pathology risk increases with the component ‘vibration’ induced by chainsaws, tractors, skidders and other machineries. In this study we have considered two different logger groups working in public forestry yards and we have analyzed their MSD risk exposure, controlling both the posture of each worker and measuring the induced vibration on the handarm system and on the back. The OWAS (Ovako Working-posture Analysis System) technique has been used to evaluate the load MSD risk and the 2002/44/EC Vibration Directive has been used to detect the exposure to vibration. In the first loggers group, mechanical trees felling (using chainsaw) and manual deforestation were the performed tasks; in the second, the operations were mechanical trees felling and log stacking (using also a tractor). The work of eight loggers was analyzed, evaluating all risk types. The result was that both the OWAS index and the vibration indicators were quite high. But others risk parameters came out that are not included in the OWAS or in the 2002/44 EC directive methodology: for example, the work related neck and upper limb disorders, which may be detected using the OCRA procedure in the case of driving powerful forestry machines.