You notice a patient's movements are being interrupted in an unusual way. Before revealing the answer, decide how you would assess whether this is obstruction.

Observe carefully whether a movement is begun, stopped partway through, and then either resumed or abandoned, in an irregular, unpredictable pattern, since this is the core feature. Note whether the difficulty affects not only voluntary actions but also habitual and reactive movements, such as failing to brush away an insect or turn toward a speaker, since obstruction can affect these too. Watch for the characteristic delayed response pattern, in which the patient answers a question only at the very last possible moment. Where possible, assess whether the effort needed to overcome the obstructed movement corresponds to any change in muscle tension, since it typically does not, suggesting the difficulty lies in initiating the act itself rather than in the muscles involved.