Which statement defines a closed environment in motor practice?

• A. Objects and surfaces do NOT move
• B. Objects or people are in motion or the support surface is unstable
• C. Only the therapist moves the person
• D. Environment changes randomly

Answer: (A)

Closed environments in motor practice are defined by stability and predictability: objects and surfaces do not move. In this setting the learner can focus on the movement itself without having to anticipate external disturbances. When objects or people are in motion or the support surface is unstable, the task conditions change during performance, requiring the learner to adapt—this is an open environment. Saying that all objects and surfaces remain still captures that stability, making it the best description of a closed environment. The other statements describe conditions that introduce variability or perturbations (moving objects/people, unstable surfaces, or random changes), which alter the task and reduce predictability.