Typical actions performed by order pickers in e-commerce warehouses include retrieving, scanning, grabbing, lifting, etc. making the human order-picker the spine of such warehouse operation.  For an order picking system based on a Goods-to-person (GtP) strategy, the repetitive motions raise many concerns. This increased frequency of actions may lead to the development of musculoskeletal diseases in the order picker’s body. Many methodologies, like human factors simulation, are available and can be utilized to assess the impact of the working environment on the human body. However, the evaluation of human factors in a simulated environment might differ from the actual case in real life since the interpretations of fatigue and discomfort can be subjective. Therefore, the objective of this paper is to validate the results obtained from the human factors simulation, by constructing a physical order picking environment and comparing the output through evaluating responses from volunteers who are subjected to similar to the simulated order picking environments and tasks. Three matrices of human factors were evaluated in this study. The study concludes that the results obtained from human factors simulation are in line with the subjective interpretation of the discomfort and fatigue experienced by the volunteers. As well as RULA ratings are similar in both cases.