A study was conducted to examine the impact, in terms of cognitive demands, of a restricted field of view (FOV) on semi-natural locomotion in virtual reality (VR). Participants were divided into two groups: high-FOV and low-FOV. They were asked to perform basic movements using a locomotion interface while simultaneously performing one of two memory tasks (spatial or verbal) or no memory task. The memory tasks were intended to simulate the competing demands when a user has primary tasks to perform while using an unnatural interface to move through the virtual world. Results show that participants remembered fewer spatial or verbal items when performing locomotion movements with a low FOV than with a high FOV. This equivalent verbal and spatial detriment may indicate that locomotion movements with a restricted FOV require additional general cognitive resources as opposed to spatial or verbal resource pools. This also emphasizes the importance of this research, as users of a system may allow primary task performance to suffer when performing locomotion. Movement start and completion times were also measured to examine resource requirements of specific aspects of movements. Understanding specific performance problems resulting from concurrent tasks can inform the design of systems.