Effect of hand posture on maximum force grip and discomfort in tractor drivers

In designing work stations, maintaining best hand posture is particularly important in achieving the highest grip power. this study aims to assess the effect of hand posture on maximum force grip and discomfort in 24 tractor drivers in sanandaj. maximum force grip in different postures using hydraulic dynamometer, and discomfort level using simulated 10-degree visual scale were measured and recorded. significant relationships were observed between hand direction and also hand-shoulder distance and maximum force grip and discomfort level. the highest force grip was achieved at hand direction angles above 90 degrees. maximum force grip was achieved at hand angle 135 degrees and hand-shoulder distance of 100 arm-reach (43.1 kg force). also, the most discomfort was found at 45 degrees hand direction and hand-shoulder distance 50 of arm-reach (58.8 kg force). discomfort level and hand direction angle affect maximum force grip, and unless these ergonomic factors are taken into account in designing hand tools and controls, consequences such as increased accidents, fatigue, and musculoskeletal problems will inevitably follow.