- BACKGROUND/STUDY CONTEXT: A manipulation check was used to investigate whether there is an age-related difference in the adherence to specific external- and internal-focus instructional constraints. METHODS: Participants stood on a force platform and were to maintain a feedback cursor (representing their center of pressure) along the horizontal direction, within a target on a computer monitor. Trials were conducted with either an external focus of attention (keeping the feedback cursor within the target) or an internal focus of attention (keeping the weight evenly distributed between both legs). RESULTS: The finding showed that younger adults followed the experimental instructions; however, older adults relied on external visual information when they were asked to focus on the body movements. CONCLUSION: Age-related declines may contribute to attention allocation differences. The authors propose that specific manipulation checks be used to ensure proper adherence to instructions when comparing age-related differences in postural control.