Outdoor fitness equipment (OFE) areas have become a popular form of built environment infrastructure in public open spaces as a means to improve public health through increased physical activity. However, the benefits of using OFE are not consistent, and several OFE accidents have been reported. In this study, we videotaped how OFE users operate OFE in parks and selected four types of popular OFE (the waist twister, air walker, ski machine, and waist/back massager) for video content analysis. Furthermore, we established coding schemes and compared results with the instructions provided by OFE manufacturers. The results revealed various usage behaviors for the same OFE types. In addition, we observed that a significant portion of user behaviors did not follow manufacturers’ instructions, which might pose potential risks or actually cause injuries. Children are especially prone to act improperly. This study provides empirical evidence indicating the existence of potential safety risks due to inappropriate usage behaviors that might lead to accidents and injuries while using OFE. This study provides crucial information that can be used to evaluate the effectiveness of OFE and to develop future park or open space initiatives.