G. Lorimer Moseley and Lester Jones
3.4 MANAGEMENT OF PAIN .1 E DUCATION
that are not anatomically focussed, for example the task-specifi c tools, whereby the patient selects a task or activity that they are unable to perform because of pain, and rates their ability to perform that task over the course of treatment. An advantage of such a tool is that it can be used with different populations. A disadvantage is that it makes it diffi cult to compare between treatments or between patients.
3.3.4 NOCICEPTIVE TRIGGERS
Investigations of structures and movements may be helpful in identifying noxious stimuli. Evidence of mechanical forces, pressure, and distention during aggravat-ing postures (static and dynamic) should be sought. Areas of chemically mediated nociception, in association with the infl ammatory mediators of peripheral sensitiza-tion, might be suspected at points of tenderness identifi ed by palpation. However, consideration of peripheral noxious stimulation should always consider the profound effects of spinal and supraspinal mechanisms on pain sensitivity.
3.4 MANAGEMENT OF PAIN
Commonly, the clinician also intervenes by modifying the infl ammation process.
Such strategies are not thought to impede normal tissue healing, but by reducing pain and swelling, they aim to get people moving more quickly than they otherwise would. Conventional fi rst aid to tissue trauma involves cooling and elevation of the injured part, fi rm bandaging, and reduced activity (rest, ice, compression, and eleva-tion) with the intent of reducing blood fl ow and protecting injured tissue.
Pharmacological agents are also employed to reduce infl ammation. Such agents are commonly designed to target the mechanisms involved in the production of pros-taglandins. Use of these “anti-infl ammatories” should be managed cautiously due to the importance of the infl ammation process in tissue healing and the drastic side effects (including gastric ulceration) associated with prolonged or inappropriate use.
Notably, the administration of anti-infl ammatories is commonly systemic (e.g., orally or by injection), so the drug effects will extend beyond the target tissue. Even in local application of topical agents, there is a risk the active agent will be transported remotely in the circulation. Only those with appropriate expertise and medicolegal authority should be involved in giving advice and prescribing such medications.
Decisions about the introduction of movement and eventual return to activity are made with regard to the state (i.e., vulnerability) of the tissues, not simply with regard to pain. This is an important point. We have outlined why pain is not an accu-rate measure of the state of the tissues, and herein lies the implication of that assess-ment. If pain is not an accurate guide to the state of the tissues, then, taking a purely tissue-focused perspective, pain is not an appropriate marker for the reintroduction of activity. Indeed, movement may be another feature that assists in the dissipation of sensitizing substances through its promotion of blood fl ow, oxygen supply, waste product removal, and appropriate forces to guide healing. Therefore, delaying the reintroduction of movement because of pain may prolong pain. The clinician needs to have sound knowledge of the processes of healing and nociception to make this judgment. That is, the clinician must have both comprehensive biological knowledge and sound clinical reasoning. Finally, the clinician needs to manage the patient’s concern about moving despite pain because it is these concerns determine both how, and how much, the patient will move.
3.4.2.2 Deactivating Spinal Mechanisms of Nociception
The desensitization of second-order neurones is infl uenced by two mechanisms, one involving peripheral stimulation and the other involving descending supraspinal infl uences. Novel peripheral input, such as transcutaneous electrical nerve stimula-tion (TENS), activates Aβ neurones. This nonnoxious stimulation “competes” with incoming nociceptive stimulation and can become the more prominent sensation.
Descending modulation of spinal activity can be facilitatory or inhibitory. Inhibi-tory effects seem to be linked to positive emotional states and direct links to the spinal neurones from the emotional areas of the brain have been identifi ed. The “gate control theory,” now more than 40 years old, postulated that lamina II of the dorsal horn of the spine was the site of this inhibition of the nociceptive system (Melzack and Wall, 1965). Pain neuroscience has grown from this theory, and despite great advances in the understanding of pain, there is still strong support for this modula-tory function of the dorsal horn. Intriguingly, there is good evidence that TENS
is effective in pain of recent onset, presumably with recent trauma, and not effec-tive in persistent pain states (McQuay et al., 1997). This may be a consequence of the greater role of sensitivity in persistent pain states we have described previously.
There is a good argument that stimulation of Aβ neurones actually facilitates dorsal horn sensitization once sensitization is underway, because spinal nociceptive neu-rones can become sensitive to Aβ input.
3.4.2.3 Targeting Cortical Representations of the Body
An effect associated with persistent pain states is the alteration of the representa-tion of the painful part in the primary sensory cortex (S1) (see Flor et al., 2006 and Moseley, 2006 for review). The plastic nature of the cortex means these changes may be due to altered neural input. That is, a change of normal tissue activity and stimulation, the so-called use it or lose it principle. However, a more specifi c mecha-nism, involving the inhibition of nonnoxious stimuli at the thalamus, has also been proposed (Rommel et al., 1999), although it is yet to be substantiated.
In any case, rehabilitation of people with persistent pain states may benefi t from attempts to normalize the S1 representation (Flor, 2003, Maihofner et al., 2004, Pleger et al., 2005). Training the nervous system to be more discriminating to sen-sory stimuli appears to be benefi cial in reducing pain for some patient groups (e.g., phantom limb pain (Flor et al., 2001) and complex regional pain syndrome (Moseley et al., 2008)). This refl ects fi ndings that tactile acuity is related to pain and changes to the S1 representation (Flor, 2003). While these fi ndings may lead to the assump-tion that changes to the S1 representaassump-tion cause pain (Harris, 1999), this is yet to be established (Moseley and Gandevia, 2005).
3.4.2.4 Reduce and Modify Psychological and Social Demands
As described earlier, it would seem that negative effects (e.g., distress, anxiety), cognitions (e.g., catastrophizing, expectations), and social factors (e.g., workplace demands) infl uence pain and the disability associated with pain. Not surprisingly then, cognitive-behavioral therapy (CBT) has emerged as a popular intervention. While there are different approaches to CBT, the literature tends not to distinguish between these approaches. Therefore, in this section, we will outline the use of cognitive-behavioral principles rather than theory, per se. The application of cognitive-behavioral principles, in a CBT framework or otherwise, aims to enhance coping skills and reduce psycho-pathology and disability. Techniques, such as goal setting, problem solving, cognitive restructuring, attention diversion, communication skills, and assertiveness training, are commonly employed. To reduce pain is not a target of CBT, but it is an effect (Morley et al., 1999).
3.4.2.5 Deactivating Brain Mechanisms of Nociception and Pain
We suggested earlier that pain is dependent on an evaluation by the central ner-vous system, of threat to body tissue. It follows then that any input that changes that evaluation will also change pain. The mechanisms for this have been suggested, but are not well defi ned. Probably, there is involvement of mechanisms that modu-late descending inhibitory and excitatory infl uences on the dorsal horn neurones as
well as suppression of activity in cortical structures (see Petrovic and Ingvar, 2002).
However, again, the principle that pain is the conscious correlate of the implicit perception of threat to body tissues is able to inform the clinical implication of these mechanisms (see Moseley, 2007 for review).
3.4.2.6 Cognitive-Behavioral Principles
The basic premise underlying the use of cognitive-behavioral principles is that an individual’s thoughts infl uence and interact with their emotions, beliefs, and behavior. Therefore, by challenging unhelpful thoughts and replacing them with more accurate and appropriate ones, improved mood and behavior can occur. With persistence, this may even lead to a reconceptualization of existing beliefs. Modi-fying behavior, for example participating rather than avoiding, allows for further challenging of preexisting thoughts and beliefs, and is also likely to positively affect mood.
3.4.2.7 Relaxation
There are many strategies, and personal preferences, for achieving a relaxed state.
However, not all strategies enable relaxation during participation in necessary or desired activity. As well it would seem appropriate to be able to initiate a relaxation response, at a time when the pain is still controllable, but might be worsening.
A recognized approach to relaxation that satisfi es these requirements combines meditative, physiological, and psychological elements. It features a mantra, a visual imagery and attention to inhalation, expiration, and the tension in muscles.
Through frequent training sessions, a relaxed state is linked to the mantra, the image, and the exhalation, allowing it to be initiated opportunistically. The benefi ts of relaxation in a person with pain include reducing negative emotional response to pain or the expectation of pain, reducing unnecessary muscle activity prior to movement, allowing more effective cognitive function and response. Compared to many other strategies, this strategy can be implemented without interruption to current activities, and hopefully allows the person to perform better and for longer periods of time.
3.4.2.8 Pacing
An identifi ed cycle of activity in many people with persistent pain involves high level of activity—usually when symptoms are low—followed by very low levels of activ-ity, in response to elevation of symptom intensity. It is sometimes called the “boom or bust cycle,” and is problematic when the periods of very low activity interfere with things a person wants or needs to do (e.g., work). Pacing aims to change this pattern of activity by avoiding the two extreme levels. The person will instead func-tion at a level that can be consistently reproduced day after day. This allows for more confi dent predictions of future performance and is more appropriate for regular par-ticipation in home, work, and social settings. Initially, the identifi ed level of activity that can be performed regularly may still be too low for participation in the person’s preferred lifestyle. However, by applying strategies, such as thought-challenging and relaxation, the individual may be able to do more despite pain.
As well, the person should be encouraged to use quotas to guide activity level, rather than pain being the guide. Quotas (e.g., repetitions of exercise, time spent on an activity) identify the level of activity to be performed regardless of the pain on the day. They should be set by the person in response to previous successful experiences.
The person must resist responding to low levels of pain by increasing activity beyond the set quota and should endeavor to reach the quota even when pain is interfering.
This should be done, with the knowledge from previous experience, that the task is achievable by challenging any unhelpful thoughts and using relaxation strategies during the task. A gradual increase in quotas allows activity to be paced up and should be achievable as the person becomes more competent in the use of cognitive strategies and used to the level of activity.
The rehabilitation professional should be able to facilitate this process of pac-ing up activity. Importantly, this requires effective education, the opportunity for the person with pain to experience successful performances, and the development of effective cognitive-behavioral strategies for self-management. Optimum levels of activity will most likely be achieved when the combined skills of thought challeng-ing, relaxation, and pacing are well developed and consistently applied (see Nicholas and Tonkin, 2004 for more specifi c detail on goal setting, pacing, and quotas).
3.4.2.9 Graded Exposure
The use of a graded exercise program is common in the rehabilitation of people with persistent pain. This has many potential benefi ts including physical improvements such as strength, range of movement, and coordination, and psychological benefi ts such as improved self-effi cacy and improved mood. There is also the possibility that there is a reduction in pain-related fear, as a person is able to confront fearful activi-ties or situations in the safety of the rehabilitation setting.
Graded exposure to fearful activities is a much more formalized approach to this, and arguably more effective (Vlaeyen and Linton, 2000). With fear as the target of the intervention, a hierarchy of situations or events is constructed ranging from a situation of no fear (i.e., baseline) to one that provokes intense fear. Treatment using graded exposure involves presenting the fear-inducing stimuli in order of the hierar-chy, progressing toward the most intense. This technique has been used successful in people with persistent pain including nonspecifi c low back pain (Vlaeyen et al., 2002) and complex regional pain syndrome (de Jong et al., 2005).
Notably, the application of these cognitive-behavioral principles forms just one aspect of the rehabilitation process, along with interdisciplinary interventions that tackle physical fi tness, ergonomic factors, and work practices.