The agriculture industry has been recognized as one of the Nation's most hazardous industries along with mining and construction, and California's agriculture industry is no exception. The most commonly reported injuries within California agriculture, in general, and the winegrape industry in particular, have been associated with musculoskeletal disorders (MSDs). Grape vineyards utilized for the production of wine are prominent and extensive in northern California with more than 400,000 acres situated primarily in the Sonoma and Napa valleys. Approximately half of the existing commercial wineries in the US are located in California, employing more than 31,000 workers per year with an additional 40-50,000 workers hired specifically for the harvesting season. There is currently an incomparable degree of new winegrape vineyard planting in process throughout the Western States. This is in part due to the rapid expansion of production capacity to meet growing worldwide demand. As new plantings are made, growers face a rare opportunity to reconsider otherwise more or less fixed structures as well. Chief among these are decisions about trellising systems. Trellises are used to create a greater plant canopy surface area to receive more sunlight and increase production. Trellis systems dictate the health effects, mostly in terms of musculoskeletal disorders, on workers performing pruning and harvesting tasks. However, unfortunately, this is not a current focus in trellis system selection since little is known about these effects, and labor costs are generally cheap. To address the void about the effects of trellis systems design on MSDs risk factors for workers performing pruning and harvesting tasks, the study's main goals included: 1. Identify and develop detailed ergonomics measurements of risk factors for musculoskeletal disorders for each of the most commonly used winegrape trellis systems. 2. Facilitate use of information about risk factors for musculoskeletal disorders associated with most commonly used wine grape trellis systems in trellis decision-making. 3. Develop practice and design parameters for reducing ergonomics risk factors associated with most used trellis systems. 4. Add to research knowledge about the association of specific agricultural workplace ergonomics risk factors and musculoskeletal disorders and their symptoms. To achieve the project's primary goals, five main studies were conducted: 1) California Major Trellis Systems, 2) Ergonomic Evaluation: Pruning Simulation, 3) Ergonomic Evaluation: Harvest Simulation, 4) Ergonomic Evaluation: Field Observations, and 5) Field MSD Symptom Surveys. The project involved over 200 vineyard workers and spanned over several pruning and harvesting seasons. These studies demonstrated the relative risk of developing MSDs among five of the common trellis systems used in the winegrape industry: The Lyre, Vertical Shoot Positioned (VSP), Smart Dyson, Scott Henry, and VSP 4x4. The project has shown that, for both pruning and harvesting, the Lyre and VSP 4x4 systems made workers assume relatively extreme trunk postures, and resulted in increased awkward wrist postures when compared with the other trellises. These combined awkward postures are expected to increase the risk of developing MSDs of both the wrist and the back. Furthermore, the Lyre system places increased MSD risk on the shoulders. On the other hand, all the studies conducted in this project consistently found that the VSP system, overall, resulted in both the least time spent in awkward trunk postures, combined with acceptable wrist and shoulder postures. The significance of these findings should have important implications to vineyards that are currently considering to plant or re-plant new vines. For a given grape variety, the trellis height does not substantially affect grape quality or vine productivity .Hence, in our efforts to reduce the risks of developing MSDs of the back and upper limbs, we have been, through various means, disseminating the findings of this study to the winegrape industry .The major message relayed is to advocate the use of the VSP system (around 42 inches), and to avoid the VSP 4x4 (around 24 inches) and the higher (above 44 inches) Lyre systems.