Simon hurt his back and was in a lot of pain, resting on the couch for several days. After a few weeks, Simon was performing his usual daily activities with no problems when one of his friends called to ask about his back. For the rest of the day, he moved much slower and was more deliberate when standing, sitting, or moving his back. This illustrates the influence of on unconsciously guided behavior

post traumatic health disorder

Explanation: Post Traumatic Health Disorder is a mental health

Condition that is triggered by a shocking,scary or dangerous event

Subtle reminder

Explanation:

The concept of subtle reminder is based on the fact that,  episodic memories(memories of events that occur everyday ) can be adjusted, revised, or changed   by a reminder of the events that lead to it.Thus subtle reminders usually activate memories of events  in human subconscious minds and interferes with emotions and behaviour of the subjects.

Therefore when Simon was reminded of his 'hurt back' of days ago, the subtle  reminder activated   episodic memories of the pain experienced during the period, and  this  interferes with his behaviour onward.