Pain is one of the most common clinical problems encountered on rehabilitation wards, and managing it requires a structured approach.

What is pain?

Pain is defined by the International Association for the study of Pain (IASP) as:

“An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage” (Raja et al., 2020, p. 14).

• • Pain is always a personal experience that is influenced to varying degrees by biological, psychological and social factors.

• • Pain and nociception are different phenomena. Pain cannot be inferred solely from activity in sensory neurons.

• • Through their life experiences, individuals learn the concept of pain.

• • A person’s report of an experience as pain should be respected.

• • Although pain usually serves an adaptive role, it may have adverse effects on function and social and psychological well-being.

• • Verbal description is only one of several behaviours to express pain; inability to communicate does not negate the possibility that a human or a non-human animal experiences pain.

These statements may seem abstract at first, but they have important implications for how we assess and manage pain in clinical practice.

When someone is experiencing pain in their hip, we are naturally drawn to thinking about their hip joint and what possible pathologies might explain it. But when we consider structural hip pathology, what we are really considering is the potential for nociception arising from the hip.

Nociception provides information about the state of the tissues, but these signals can be modified – amplified, dampened or even suppressed – by the central nervous system. Pathology does not always result in pain and this becomes more pronounced as pain persists and transitions into chronic pain (> 12 weeks). 

For example, cross-sectional studies show that people with radiological osteoarthritis are just as likely to have pain as they are to be pain free (Ding et al., 2010). Similar patterns are seen in other conditions. Neuropathic pain is present approximately half the time in people with diabetic peripheral neuropathy (Gylfadottir et al., 2020).

This distinction is central to rehabilitation medicine. Our task is not only to treat tissue pathology or know how the nervous system interprets and responds to signals from the body, but also to understand the person’s pain experience.

Pain can be understood as one of the body’s danger-detection systems – warning that we may be harmed, are being harmed or have been harmed in the past.

If the nervous system perceives less danger, the experience of pain often reduces. Understanding how to influence this system is a powerful clinical skill.