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Abstract
Pain is a common problem among elite athletes and is frequently associated with sport injury. Both pain and injury interfere with the performance of elite athletes. There are currently no evidence-based or consensus-based guidelines for the management of pain in elite athletes. Typically, pain management consists of the provision of analgesics, rest and physical therapy. More appropriately, a treatment strategy should address all contributors to pain including underlying pathophysiology, biomechanical abnormalities and psychosocial issues, and should employ therapies providing optimal benefit and minimal harm. To advance the development of a more standardised, evidence-informed approach to pain management in elite athletes, an IOC Consensus Group critically evaluated the current state of the science and practice of pain management in sport and prepared recommendations for a more unified approach to this important topic.
- Athlete
- Consensus Statement
- Drug Use
- Ethics
- Injury
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Background
The IOC convened a consensus meeting from 2 to 5 November 2016, at which experts reviewed the scientific literature addressing pain management in elite athletes. We searched for and analysed current best evidence, with the aim of reaching a consensus regarding the quality of the evidence in order to provide guidance for clinical practice and athlete management.
The group was charged with the following
to review the literature describing pharmacological and non-pharmacological treatments for the management of pain in elite athletes
to review the literature on the physiology of pain related to sport injury
to establish core ethical and clinical principles for the management of pain in elite athletes
to provide a sound rationale for the best-practice management of pain in elite athletes
to provide a rationale for the prohibition of certain analgesics and the basis for appropriately granting Therapeutic Use Exemptions for their use
to provide a review of the risks and benefits of the use of analgesic medications in sport including short-term strategies to permit competition with optimal pain management.
This consensus paper fulfils the IOC charge by addressing the multifaceted aspects of pain physiology and pain management in elite athletes through the lenses of epidemiology, sports medicine, pain medicine, pain psychology, pharmacology and ethics.
Prevalence of use of pharmacological and non-pharmacological treatments to manage pain in elite athletes
Elite athletes commonly use prescription and over-the-counter analgesics to prevent or relieve pain.1–18 These have typically included: oral non-steroidal anti-inflammatory drugs (NSAIDs),2 4 6 16 17 injectable NSAIDs,5 other non-opioid analgesics,1 4 8 9 opioid analgesics,1 3 4 7 8 10 18 injectable and transdermal anaesthetics11 and other medications and over-the-counter supplements.1 3 12–15
Despite the perception that the use of medications and non-pharmacological strategies to relieve and prevent pain is widespread in sport,8 9 12 we could identify no comprehensive assessment of the frequency and effects of such use among elite athletes. Accordingly, a systematic literature review focusing on elite athletes’ use of medications for pain was completed. The results are presented in detail in a separate article (Harle CA, Danielson EC, Smith L, et al. Analgesic management of pain in elite athletes: A systematic review. 2017, personal communication). A survey completed by team physicians during the 2016 Summer Olympics in Rio de Janeiro provides insight into physician prescribing patterns and is attached in supplementary online appendices A-C.
Types of pain
‘Pain management’ includes a general understanding of pain physiology, including types of pain. By understanding types of pain, the clinician can better recommend an appropriate treatment plan. For a detailed discussion of core principles of pain physiology and pain management, the reader is referred to an accompanying article on this subject.19
Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.20 (See supplementary online appendices A-C for definitions of key terminology.) Pain can be classified as nociceptive, neuropathic or nociplastic/algopathic/nocipathic.21–23 Nociceptive pain refers to pain clearly associated with tissue damage or inflammation.20 21 This is the type of pain most commonly associated with sport injury.20 23 Inflammatory pain is a type of nociceptive pain that results from the activation and sensitisation of nociceptors by inflammatory mediators21 and is common in acute traumatic sport injury with associated swelling and inflammation.21 Neuropathic pain results from a lesion or disease in the somatosensory nervous system20 and is common in Paralympic athletes with spinal cord injury.24 A third type of pain is common among individuals with chronic pain. These individuals have chronic pain that is neither nociceptive nor neuropathic but associated with clinical and psychophysical findings (hypersensitivity) that suggest altered nociceptive functioning (eg, as in fibromyalgia, non-specific low back pain). Terms proposed for this third type of pain include nociplastic, algopathic and nocipathic.23 Studies in athlete populations are lacking, but it is plausible that pain in the immediate aftermath of most sport injuries is nociceptive associated with tissue damage, and nociplastic/algopathic/nocipathic pain may develop after injury and may be seen in athletes with chronic pain.
Mechanisms and types of injury
The IOC has defined sports injury as new or recurring musculoskeletal complaints incurred during competition or training that require medical attention, regardless of the potential absence from competition or training.25 Others have suggested that a definition of sports injury should require restricted activity for at least 1 day.26 (See appendix B for definitions of key terminology.)
Acute traumatic injury refers to a single event that leads to a singular macrotrauma on previously healthy tissue.27 Acute traumatic injury in the athlete may be accompanied by fear, anxiety and heightened cognitive focus on the injury.28
Overuse injuries occur from repetitive submaximal loading of the musculoskeletal system when inadequate recovery has not allowed structural adaptation to occur.29 30 Injury, then, is the outcome of the difference between the volume and intensity of the stress or force applied to the body and the body’s ability to dissipate this stress or force. Injury may result from repetitive microtrauma imposed on otherwise healthy tissue or repeated application of lesser forces to already damaged tissue. In essence, athletes are not training at an optimal workload to build physical capacity and resilience to the demands of the sport.31 32
Subacute recurrent injuries and chronic degenerative conditions may form a continuum with overuse injuries. A recurrent injury is an incident of the same type and at the same site linked to an index incident, which occurs after an athlete’s return to full function and participation from the recorded index incident.33 Although degenerative conditions may develop independent of sport injury, some result from prior acute or repetitive overuse injuries and manifest as a chronic overuse injury.34
Core principles of making a diagnosis in elite athletes in pain
Sports medicine commonly focuses on the diagnosis and management of sport-related injury. Pain medicine focuses on the diagnosis and management of pain disorders. Importantly, injury may occur without pain, and pain may present without evidence of injury. When performing a history and examination of an elite athlete in pain, the sports medicine clinician should discern if there is an injury that reasonably accounts for pain. Pain management and injury management are not necessarily identical, as discussed in detail in this paper. Supplementary online appendices A-C provides an overview of core principles of diagnosis in elite athletes in pain.
Non-pharmacological pain management strategies in elite athletes
Non-pharmacological pain management should be considered in the earliest stages of pain and is essential in pain management beyond the acute phase. Pain is a subjective experience dependent on complex interactions of neurobiological, cognitive, affective, contextual and environmental factors. Thus, pain management depends on identifying contributory factors from biological, psychosocial and contextual domains and addressing them through various evidence-based techniques.35–37 Educating the athlete regarding the role of the central nervous system in pain, especially in chronic pain, can increase receptivity of the athlete to a biopsychosocial approach to pain management.35
Physical therapy is important for most pain problems, especially in subacute and chronic phases.38–40 In addition to therapy targeted at increasing strength, stamina, and endurance, and at correcting biomechanical contributors to pain and injury, trained and informed physical therapists can act as front-line clinicians who identify and address inaccurate conceptualisations of pain and injury plus psychosocial and contextual influences on pain.41–44 Psychological strategies, which can begin immediately after injury, also target pain management directly through training in skills such as muscle relaxation and imagery, as well as indirectly by identifying and addressing an athlete’s worries and concerns, any comorbid mental health disorders and environmental factors relevant to recovery and return to play (RTP).45 46
Modalities and massage
Various modalities and massage have traditionally been the mainstays of physical therapy for pain.38–40 47–50 The Rio Survey indicated that over 75% of physicians surveyed used physical therapy for pain management (appendix A). Recent studies, however, show that many physical therapy techniques have no clear benefit beyond non-specific effects and natural history, with some exceptions. Low-level laser therapy may be beneficial in treating tendinopathy and improving acute muscle recovery.51–55 Although cryotherapy is commonly used, there is little evidence from prospective studies assessing the benefit of this intervention.55–57 Ultrasound therapy may have a limited role in managing plantar fasciitis57 but has not demonstrated effectiveness in other studies.58 Electrical stimulation,50 59–61 massage therapy,49 62–64 myofascial trigger point treatments65–68 and acupuncture69–71 have not shown reliable and consistent efficacy for relief of pain resulting from musculoskeletal injury.
The effects of modalities may be manifest in an individually specific way, especially as it pertains to the skill of the treating clinician.62 72–76 That is, the patient’s and the clinician’s expectations and skill, respectively, about a particular treatment’s mechanism and effects are potentially powerful determinants of outcome.77–79 The practitioner needs to balance the relative weight of expectation of benefit (and therefore likely benefit) with potential risk.
Movement, strength and conditioning
Movement and exercise may have pain-relieving effects.80 81 Strength training and conditioning are effective as rehabilitation tools after injury. They can also be helpful in managing pain and reversing deconditioning in individuals with chronic painful conditions such as osteoarthritis,82–85 fibromyalgia86–93 and chronic musculoskeletal pain.94 95 Exercise can activate endogenous opioid96 and cannabinoid systems,97 induce an anti-inflammatory state98 and activate antinociceptive pathways.96 99–102 Isometric exercise can promote intracortical inhibition (which downregulates brain networks that subserve pain) and may offer significant pain-relieving benefits beyond those offered by isotonic and eccentric exercises for managing tendinopathy.103–105 Although data from athletes are lacking, there is evidence in other pain populations (particularly chronic pain) that movement and exercise-based approaches can improve patient self-efficacy for managing pain and fear of (re)injury.35 45
Psychosocial interventions
Psychosocial interventions with possible efficacy in sports rehabilitation include skills training in goal setting, imagery, relaxation and positive self-statements.106 Stress inoculation training was shown to reduce anxiety, pain and days to recovery after arthroscopic surgery for meniscus injury.107 Other interventions relevant to athletes include cognitive restructuring (identifying and challenging negatively biased appraisals) and developing plans for maintaining treatment gains and coping with setbacks and pain flare-ups.106 These strategies are broadly categorised as cognitive–behavioural therapies (CBTs). CBT is the prevailing psychosocial treatment for chronic pain problems, and there is high-level evidence of its efficacy in reducing pain and pain-related disability in studies of non-athletes.106 108 109 Psychologically informed physical therapy, which incorporates cognitive and behavioural principles and strategies (eg, techniques to reduce fear-avoidance, use of graded activity and exposure techniques), and education about pain during physical rehabilitation, is a promising approach with some evidence supporting its use.35 110 Psychological assessment and intervention by a specialist should be normalised by the treatment and coaching team, so that it can be implemented when necessary and without stigma.
Sleep and nutrition
Disordered sleep is common among athletes, both when recovering from injury and during the competition and training seasons.111 112 Sleep and pain have a reciprocal relationship—pain disturbs sleep, and poor sleep quality or duration increases pain levels in clinical populations and decreases pain thresholds in otherwise healthy people.113–119 Addressing sleep disorders could improve performance and the general health of the athlete.112 Psychological strategies including CBT,120 self-hypnosis121 and mindfulness-based stress reduction122 show significant potential to improve sleep in non-athletes. CBT for insomnia has demonstrated efficacy.123–125 Studies in athlete populations are lacking, but it is plausible that these results would be generalisable to athletes.
Persistent pain is influenced by any proinflammatory load,126 which makes nutrition possibly relevant to managing pain in athletes. However, studies demonstrating benefit from nutritional supplements are not methodologically sound and have unclear relevance to elite athletes.127–139 Furthermore, supplements are poorly regulated and may contain banned substances. Consequently, supplements cannot currently be recommended as part of pain management for elite athletes.
Surgery
Elective surgery has no place in the treatment of pain itself but may address structural damage non-responsive to non-operative treatment, or to avoid further impairment of an athlete’s health.140 An operation for a chronic injury and pain condition must aim to correct a structural problem that influences pain and functional limitations141–143 and should occur as part of a multifaceted, biopsychosocial management approach.144 Surgical intervention includes setting individual treatment and outcome goals for the athlete. The athlete must have a complete understanding of the risks and benefits and accurate expectations about postsurgical recovery and pain. When appropriate, surgery can be part of a multidisciplinary approach for pain reduction. Surgery should not be performed to treat chronic pain simply because all other interventions have failed but should rather be used when a structural problem associated with the pain has been identified.140
Pharmacological pain management strategies in elite athletes
Guiding principles
Appropriate and effective pain management requires a thoughtful and individualised approach to evaluation and care, including an assessment of the implications of treatment for both short-term and long-term health.145 The prescription, or provision, of medication is common to the management of pain in elite athletes. Analgesic medications should be used in accordance with relevant regulations and the general guidelines for their safe and efficacious use.146 The core pharmacological principles of pain management in elite athletes include:
Medication prescription should be only one component of managing pain. Combining medication use with appropriate non-pharmacological measures limits disability and optimises probability of improvement.
Medications should be prescribed at the lowest effective dose for the shortest period of time. They should be discontinued if they are ineffective or not tolerated, and as the pain from the injury resolves.
Medications should be prescribed in a manner consistent with established, recognised pharmacological and pharmacodynamic principles, including route of administration, time of onset of action, effectiveness for pain relief and potential side effects and complications. Consideration of an athlete’s medical and medication history is essential.
Physicians prescribing analgesic medications to athletes should possess a complete understanding of the prevailing rules and regulations regarding prohibited substances and Therapeutic Use Exemptions specific to the governing body that controls the athlete’s sport.
Recording athlete-reported severity of pain (eg, with a numerical rating scale) can be useful in monitoring the effectiveness of a medication.
Prescription medications should only be provided to athletes by licenced healthcare providers who understand potential side effects or misuse of medications, and whose licensure includes this scope of practice. Written documentation of each assessment and prescription is a basic standard of care.
Informed consent is fundamental in medical care, including those situations in which medication is prescribed. This is also true for care of the elite athlete; however, obtaining such consent can be challenging in competitive situations when an athlete seeks same-day RTP. At a minimum, any substantial risk of short-term or long-term worsening of an injury should be discussed and documented.
Medications should not be prescribed to athletes for pain or injury prevention.
Medication management based on pain severity and anticipated RTP
I. Medications for managing acute pain in the elite athlete on the same day as the injury: on the field of play, sideline or locker room
Physicians providing care at a practice or game/match scenario should have a comprehensive emergency medical action plan, including provisions for acute pain management.147 Pain management may depend on whether same-day RTP is contemplated.
No same-day RTP
A major acute injury with associated severe pain may require pain management on the field of play or on the sidelines (table 1). Extending the hospital emergency department onto the field of play may be necessary. The severely injured athlete must receive effective pain treatment as soon as possible, and certainly before any prehospital treatment (eg, manipulation or splinting) is attempted.147
Medications for managing acute, severe pain from a severe injury that does not allow same-day return to play
Same-day RTP
Medications may play a central role in the management of an athlete with acute pain who is considered for same-day RTP. Paracetamol, NSAIDs and local anaesthetics are commonly employed in such situations148–158 (table 2). Knowledge of relevant pharmacokinetics, including time to onset of action and plasma concentrations, is valuable. The primary determinant when providing analgesics in same-day RTP situations is the athlete’s safety.146 157 Analgesia that allows competition should not place the athlete at risk of worsening injury.
Medication management for acute pain and same-day return to play
For mild to moderate pain, paracetamol, alone or with NSAIDs, will usually suffice.153 158 Paracetamol does not have an effect on the gastric mucosa, renal function or platelet activity–considerations that should figure prominently in prescribing analgesic medication to those participating in sport.159 NSAIDs may be slightly more analgesic than paracetamol160 and together provide more pain relief than either alone.158 161 It is important that paracetamol be given in sufficient dosing, including a 2 g loading dose and 1 g every 4–6 hours thereafter, as needed.162 Intramuscular ketorolac has been widely used in certain elite sports because of possible greater analgesic efficacy without significant reported side effects,5 although concerns remain163 and prescribing recommendations are narrow.5 164 If the injury develops with an ongoing haematoma, ketorolac and traditional NSAIDs may worsen the bleeding, whereas this is no concern with paracetamol or a COX-2 selective NSAID.165 Topical anaesthetics may provide relief of well-localised, more superficial conditions such as intercostal pain.157
For moderate to severe pain, paracetamol and NSAIDs remain an option, including paracetamol with ketorolac. Opioid use in an opioid-naïve individual is usually associated with cognitive, behavioural and reaction-time effects detrimental to individual performance166 167 and may theoretically place other athletes at risk in sports that require quick reaction time in a crowded space (cycling and basketball). There is no compelling evidence demonstrating that opioids such as tramadol and codeine provide pain relief that is superior to NSAIDs.155 Tramadol can also impair reaction time in tramadol-naïve individuals.155 Thus, opioids have little or no role in same-day RTP; if anything, they are ergolytic, not ergogenic.
Injected local anaesthetics have also been used for moderate to severe pain and same-day RTP in elite athletes, either pregame or during competition.152 154 There are some limited data from a case series of National Rugby League players.154 Most governing bodies, including the World Anti-Doping Agency (WADA), have not banned these injections.168 Intra-articular injections of local anaesthetic should be avoided into weight-bearing joints or as intratendon or intraligament injections.152 154
Corticosteroid injections have no role for same-day RTP. They do not provide pain relief superior to that of local anaesthetics169 170 and can cause acute muscle/tendon weakening, thereby increasing the chance of injury.169–172 Other injections, such as platelet-rich plasma (PRP) and intra-articular viscosupplementation, are not useful for same-day RTP.173–176
II. Medications for managing mild to moderate acute pain in the elite athlete beyond the day of injury
Medications should not be prescribed as a stand-alone treatment when managing acute pain beyond same-day RTP in athletes.145 It is essential to diagnose the injury and the cause of pain and to begin rehabilitation that addresses both. Thus, non-pharmacological strategies should begin immediately.
Medications for acute pain should normally not be used for more than 5 days.151 177 178 The Rio Survey (supplementary online appendices A-C) indicated that 31% of physicians usually prescribe NSAIDs for 1–2 days’ duration, 42% prescribe a 3–5 day course and 21% prescribe NSAIDs for longer than 7 days. Even for more severe injuries with associated moderate to severe pain, medications should be re-evaluated if pain persists beyond 10 days. The process should address the underlying injury or pathology and the possibility that pain characteristics are changing (see below).151 178
The most appropriate medications for treating mild to moderate acute pain in the elite athlete beyond the day of injury include oral paracetamol and oral NSAIDs.151 157 158 (box 1) Both provide good pain relief, but the risk–benefit profile is considerably different. Paracetamol is a non-specific analgesic without anti-inflammatory agents and usually lacks other systemic side-effects when used in prescription doses. Hepatotoxicity occurs in daily doses greater than 4 g.159
Medication management for acute pain (pain duration less than 4–6 weeks) beyond the day of injury
Mild to moderate pain
Oral paracetamol, non-steroidal anti-inflammatory drugs, topical analgesics, as per table 2.
Corticosteroid injections (equivocal evidence):
Intra-articular
Bursal
Peritendinous
Epidural
Facet
Sacroiliac
Severe pain commensurate with injury
Consider adding opioids:
Initial prescription not to exceed 5 days
No opioid prescription beyond 10 days
The choice of paracetamol versus NSAIDs148 may have more to do with physician preference in using one medication or another. NSAIDs may be slightly more analgesic than paracetamol,160 but together provide more pain relief than either alone.158 161 If there is no known inflammatory contributor to pain, paracetamol is preferable to an NSAID because of its lower risk profile in the majority of people.151
Corticosteroid injections must be coordinated carefully with other aspects of rehabilitation, since their suppression of the inflammatory cascade may hinder tissue healing.173 174 Their pain-relieving effects may result in worsening of the injury if the exercise programme exceeds the capacity of the injured tissue.173 174 Overall, the evidence suggests that corticosteroid injections may provide pain relief and hasten rehabilitation but do not improve tissue healing.179–190 The incidence of complications of corticosteroid injection in treating athletic injuries is unknown.169 171 172
Two other types of injection therapies used are PRP therapy and viscosupplementation. PRP has been used to address a variety of conditions ranging from acute muscle injury to tendinopathy to osteoarthritis. The literature on the efficacy of PRP has been hampered by methodological limitations. Although some encouraging results have been reported, more large, methodologically rigorous randomised, double-blinded studies are needed before endorsing this treatment.175 176 191–198 Viscosupplementation has been most studied in the treatment of knee osteoarthritis. The highest quality randomised controlled studies show only mild pain relief and functional improvement compared with placebo injections.199 200
III. Use of medications for managing severe acute pain in the elite athlete beyond the day of injury
When an athlete has severe acute pain, relief of pain is not only humane but may be necessary to facilitate early mobilisation.201 202 The Rio Survey indicated that 71% of the Olympic team physicians surveyed considered the ability to enable rehabilitation exercises to be an important factor when forming a treatment plan for an athlete (supplementary online appendices A-C). It is reasonable to begin treatment with paracetamol and/or NSAIDs, as indicated.148–151 203 204 Injection medications may also be considered.173 174
In a dose-dependent manner, opioids are the most effective medications for severe acute pain.205–208 However, many risks are associated with opioid use. Thus, before prescribing opioids, the physician should209–214:
make a diagnosis that includes assessment of pain and its relationship to the injury, including whether the athlete’s pain seems appropriate for the injury
establish and measure goals for pain relief and improved function
assess current status and personal history with respect to mental health and alcohol and other substance use, validate such history with other health professionals involved in the patient’s care if necessary and incorporate strategies to mitigate risks of opioid use
Begin first-line non-opioid therapy and evaluate adherence to and effectiveness of the treatment before considering initiation of opioid therapy unless pain is severe and clearly associated with an injury consistent with that level of pain
prescribe the lowest effective dose and limit prescription of opioids to 5 days. Ongoing use can be reconsidered but should rarely exceed 10 days and should be accompanied by informed consent regarding the risks of opioid dependence or addiction as well as overdose, especially if used in combination with alcohol or benzodiazepines.
opioid use beyond 10 days should be considered with caution. Opioid therapy is rarely appropriate for longer than 10 days after an acute painful injury. Risks increase substantially with the number of days opioids are used. Opioid use for more than 7 days after painful musculoskeletal work injury has been associated with increased odds of disability 1 year later.215 The likelihood of chronic opioid use increases with each additional day of medication supplied starting with the third day, with the sharpest increase in chronic opioid use observed after the 5th day on therapy, a second prescription or refill and an initial 10-day or 30-day supply.216 If opioids are prescribed for more than 10 days, it is essential to have a plan in place for limiting risk of diversion and a plan and timeline for discontinuing opioid use.
IV. Medications for managing subacute and chronic pain in the elite athlete
Pain associated with sport injury may be acute (up to 6 weeks), subacute (6–12 weeks) or chronic (3 months or longer).217 When pain has persisted beyond 6 weeks of an injury or inciting event, the influences on pain and disability should be re-explored. In most cases, there is no sound rationale for long-term use of NSAIDs for pain management in elite athletes.151 177 178 Although paracetamol may be used intermittently, there is no strong rationale for using this class of medication beyond the acute period.151 Considerable caution should be used in considering the use of opioid medication to treat subacute or chronic pain, given the serious risks and lack of evidence regarding benefits associated with long-term use.209 210 Importantly, individuals whose pain has not responded to treatment and who develop subacute and chronic pain have a higher risk profile for addiction and comorbid psychiatric conditions.205 208–213
Perhaps the most important consideration in managing subacute and chronic pain in elite athletes is to shift the treatment approach from relieving pain to improving function and preventing chronic pain and associated disability (table 3). Treatment should involve a multidisciplinary approach.218–221 Analgesic medications used to treat acute pain in elite athletes should rarely be used for subacute and chronic pain. Athletes should be informed that analgesic medications carry risks, especially when used long term.222–225
Acute, subacute and chronic pain: definitions and treatment implications
Chronic pain may be associated with psychosocial factors, including mood and sleep disturbance, fear of pain and reinjury, avoidance of activities believed to increase pain or cause physical harm, concern about not achieving pre-injury level of proficiency and perception of being disconnected from coaches and teammates.41–46 226 It is especially important to address the common comorbid conditions of depression, anxiety and sleep disorder.222 223
Before beginning adjuvant medications for chronic pain, if possible the athlete should be evaluated by a clinician with experience in managing chronic pain.219 Consideration should be given to pain being driven by peripheral nociceptive activation versus neuropathic or nociplastic/algopathic/nocipathic pain. The most commonly used adjuvants for treating chronic, neuropathic or nociplastic/algopathic/nocipathic pain are anticonvulsants and antidepressants222 227–232 (table 4). Caution must be applied for treating adolescent elite athletes with adjuvant medications. For more localised pain, second-line medications include capsaicin patches (8%) and lidocaine patches. Tramadol may have a role in some cases of chronic pain because of its dual mechanism of action as a weak opioid and an upregulator of the serotonin system, but more research is needed to increase knowledge of benefits and risks.229
Selected adjuvant medications for neuropathic and nociplastic/algopathic/nocipathic pain in adults*
V. The special case of cannabinoids
A cannabinoid is one of a class of diverse chemical compounds that activates the endogenous endocannabinoid system.233 Exogenous cannabinoids include phytocannabinoids such as tetrahydrocannabinol and cannabidiol, and synthetic cannabinoids such as K2 and ‘spice’. Cannabis has been cited as possibly a useful substance for pain management.234–236 Indeed, it has been said in the popular press that cannabis is safer than opioids and should be used instead of opioids for managing chronic musculoskeletal pain in American football players.237 However, current evidence suggests that opioids should rarely be prescribed for chronic musculoskeletal pain,209–213 and evidence is lacking concerning the benefits and risks of cannabis for chronic musculoskeletal pain management. Cannabis has no role in the management of severe acute pain, as no studies have demonstrated its efficacy in this situation.238
Cannabinoids have been studied for treatment of pain conditions including neuropathic pain, fibromyalgia, spinal cord injury, spasticity from multiple sclerosis, HIV neuropathy and cancer pain. In general, the studies are short term and small and show minor or modest improvement in pain relief.239 240 There is good evidence that cannabinoids have a modest analgesic effect for some pain conditions such as, for example, refractory neuropathic pain.241 242 Cannabinoids are considered possible third-line agents for some chronic pain conditions.243 Cannabinoids are considered ergolytic,243 and like opioids, carry risks, including addiction. In summary, current evidence does not justify the use of cannabinoids for pain management in elite athletes.
Pain management strategies when expected recovery is delayed
It should be kept in mind that pain is a conscious experience that can be influenced by a variety of factors, including nociceptive activity and cognitive and affective factors. Pain is not necessarily related in a linear manner to nociceptive input.24 Optimal clinical management continually evaluates these various influences on pain independent of injury. Unique considerations for the elite athlete in pain relate to competitive requirements and demands and relationships between the athlete and his/her professional and medical teams. The motivation of elite athletes to maximise bodily performance is another factor in pain assessment and has important implications for management in a clinically optimal and ethically appropriate manner.41–46 226
Pain management plans should be communicated openly with the athlete and all those involved in management of the athlete’s injury, recovery and RTP. A plan for reassessment at critical time points should be established and clearly communicated to all parties, especially when athletes change their treating team during their recovery. This protocol should include the plan for injury and pain management and information about the predicted time course of pain, rehabilitation and key milestones.201
In the acute phase, emphasis should be on reassuring the athlete and providing education about realistic expectations, the normal course of the injury and associated pain (figure 1).28 244 The athlete should understand his/her role in optimising recovery. Accurate injury diagnosis underpins expectations about the path to recovery and pain resolution. Most athletes will recover from injury in the predicted manner.245 However, monitoring recovery closely, quickly identifying any deviation from the predicted path (figure 1) and re-assessing if recovery is not occurring as predicted are all of critical importance.
Pain variation following injury based on influences of pain. Adapted with permission, Butler DS and Moseley GL: Explain Pain, 2nd Edition, Noigroup Publications, 2013.
There is ample literature and clinical experience regarding anticipated recovery from many sport injuries.245–252 Box 2 provides a checklist that can be used clinically to evaluate need for further assessment. When pain fails to improve as expected, or changes in its distribution or quality, a prompt reevaluation is indicated, with three distinct but related objectives: (1) determination of whether the initial diagnosis is correct; (2) determination of whether the injury is healing as expected; and (3) identification of important non-injury factors that may be influencing the pain. Each objective may require assessment by a different clinician, further imaging or other testing. In most cases, the physical therapist (or other treating clinician such as athletic trainer) should be involved in monitoring recovery milestones, minimising impact of the injury and optimising return to performance. When the athlete’s pain interferes with recovery in an atypical manner, the physical therapist and other treating clinicians must assess and respond to possible contributors, including biomechanics and the kinetic chain continuum, and psychosocial and contextual domains.24 253 254
Checklist to assess need for further evaluation
(Positive response indicates risk of deviation from the predicted path to recovery)
Is the pain worsening, spreading or both?
Is pain occurring at rest or during the night?
Has any new pain emerged in other anatomical locations?
Does the pain fluctuate in a manner not explained by mechanical load?
Does the pain seem out of proportion to the severity of the injury?
Is the quality of the pain changing or is the pain becoming more distressing?
Has the athlete’s expectations of recovery changed for the worse?
There are two clear triggers for involving psychological assessment and treatment: (1) the clinician may identify psychosocial issues likely contributing to poor recovery and requiring a specialist; or (2) pain and function have not improved as expected within a few weeks after injury.28 247 248 251 252 A psychologist can assess modifiable psychosocial influences on pain, treatment adherence and pain-related performance issues, and work with the athlete to address these barriers to recovery. Key psychosocial factors associated with poor treatment adherence and outcomes after sport injury include mood disturbance, fear of reinjury, concern about not achieving preinjury level of proficiency and feeling disconnected from coaches and teammates.20 24 253–256 Other more general psychosocial influences include anxiety, stress, catastrophising (excessively negative appraisals of pain and its implications), depression and maladaptive fear of pain and re-injury and consequent avoidance of activities believed to increase pain, cause physical harm or both.24 42 44 226 254 Finally, other mental health problems (eg, eating or substance use disorders) can also impede recovery and require a psychologist’s intervention. The assessment must also evaluate the context and meaning of the prolonged pain and slow return to performance.252 257–259
Antidoping issues in pain management
‘Narcotic Analgesics’ was a category of the initial IOC ‘Prohibited’ list.168 The ‘Narcotics’ section was retained in the ‘Prohibited List’ developed by the WADA, its IOC successor (see table 5). Cannabis was also added to the WADA Prohibited List. Despite public perception that analgesic use might allow athletes to enhance performance, there is scant evidence to support this hypothesis, as noted below.
2017 WADA Prohibited List
Substances or categories may be added or subtracted to the Prohibited List annually, via a process that includes extensive stakeholder feedback and deliberation by experts, based on the latest scientific evidence available. A substance will be considered for inclusion in the Prohibited List if it meets two out of the three following criteria:
Use of the substance would enhance or has the potential to enhance sport performance.
Use of the substance poses an actual or potential health risk.
Use of the substance would be seen as contrary to the ‘spirit of sport’.
Therapeutic Use Exemptions (TUEs) allow the use of a prohibited substance to treat legitimate medical conditions or injury.260 The criteria for granting a TUE include the following:
The absence of treatment would pose a significant detriment to the athlete’s health.
Treatment will produce no performance-enhancing effect, other than the return to the athlete’s normal state of health.
No reasonable permitted therapeutic alternative exists.
TUEs can also be provided retroactively, if the treatment was provided in an acute situation. Retroactive TUEs are also allowed under exceptional circumstances, such as insufficient opportunity to submit an application.
There is limited literature to suggest that any analgesics enhance performance. Small, unblinded studies typically involving non-elite subjects have suggested that paracetamol can improve time to exhaustion261 or decrease perceived exertion in a graded run.262 263 NSAIDs have no effect on sprinting,264 vertical jumping or endurance running performance but can decrease soreness.2 264–266 Opioids can decrease pain266 and increase anaerobic performance266 but not overall physical performance after muscle damage.266 Opioids can increase tolerance to pain associated with tourniquet-induced ischaemia,267 but the translation to elite athlete performance is unclear. Attenuated afferent feedback following opioid use may cause a greater rate of accumulation of muscle metabolites and excessive development of peripheral muscle fatigue.268 Cannabis can reduce anxiety,243 269 but no ergogenic effects have been demonstrated.243 270
Pain management decisions should be made carefully, respecting confidentiality issues and ensuring appropriate consent where appropriate. The use of analgesics should be guided by pain severity and anticipated RTP, as noted above, and by the core principles described in this consensus document. Items on the Prohibited List should be used sparingly to globally regulate this important area of professional practice and allow individualised yet responsible treatment.
Special considerations: Paralympic athletes
Para-athletes can experience more pain than their able-bodied counterparts, perhaps because of an increased incidence of injuries in their sports, or the nature of a specific impairment.271 272 Although pain or discomfort in para-athletes can be a common clinical feature among those within each of the 10 recognised impairment categories, more severe pain can occur in those experiencing stump pain, phantom limb pain, spasticity-related pain or in those who have suffered spinal cord injuries.273
Central neuropathic pain is common in athletes following a spinal cord injury or stroke or in those with multiple sclerosis.274 One study estimated the incidence of neuropathic pain following a spinal cord injury to be 53% for neuropathic pain at the level of the lesion, and 27% for neuropathic pain below the level of the lesion.275 Phantom limb pain can affect up to 80% of lower limb amputees, and pain in the stump residuum can occur in 55%–76% of these individuals.276 Chronic musculoskeletal pain is estimated to occur in 60%–80% of individuals with cerebral palsy and reflects increased muscle tone, dystonia and spasticity.277 278 The use of pain medications, particularly those used to treat chronic neuropathic pain, is therefore higher in para-athletes than in their able-bodied counterparts.279 280
Ethical issues
Understanding how pain is experienced by an athlete is important.281 Part of the socialisation of athletes in male sport includes a degree of (hyper)masculinisation, leading to efforts to disregard or downplay pain and injury.282 Similar norms may exist in women’s and girls’ sports.283 More recently, the literature has addressed the phenomenology (felt experience) of pain284; pain may be an everyday experience for elite athletes, and an abrupt change in pain experience may indicate a clinically relevant change in biomechanical, psychological or social factors.285
Managing pain in elite athletes must account for the tension between ignoring or masking pain versus understanding the protective role of pain in the presence of injury. The IOC medical code is clear in this regard and asserts that ‘The health and the welfare of athletes are pre-eminent and prevail over competitive, economic, legal or political considerations’.286 This principle emphasises the primacy and protects the integrity of the clinical encounter, which is pre-eminent in ensuring appropriate pain management. Pain and injury mechanisms can be complex; the clinician must have appropriate time and space to diagnose and delineate treatment options.
The principle of respect for patient autonomy is codified in procedures for informed consent.287 These processes seek to assure the patient’s comprehension and his/her voluntary decision making. It is not always clear when an athlete makes an informed choice to ‘play through pain’ and when he/she may be under duress from stakeholders within their sports environment.288–290 The principle of non-maleficence (do no harm) must guide the clinician’s actions and recommendations to the patient in acute pain. In chronic pain contexts, however, there are broader opportunities for discussions with the patient, including an evaluation of short-term and long-term goals, the potential for emotional conflicts that may arise with prolonged suffering and the possibility of more pronounced external influences on ethical decision making.281 291 Therefore, an informed and well-documented discussion should occur between the clinician, the broader healthcare team and the athlete when considering approaches to the management of chronic pain.292
Future directions
Pain management in the elite athlete should always follow principles of good medicine, be multidisciplinary and occur with the understanding that pain and injury are not the same. Further research and increased consistency in measures and methods across studies are needed to better understand the incidence and prevalence of analgesic medication use in sport, and the benefits and risks of various pharmacological and non-pharmacological treatments, and their combinations, for specific pain presentations. There is an urgent need to increase awareness of sports medicine physicians of recent advances in the understanding of pain and its management through evidence-based guidance, as well as for increased research on pain and its management in elite athletes, in order to improve treatment of this important problem. Given that pain is commonly self-managed by athletes using over-the-counter pain medications or supplements, information specifically aimed at athletes on the safe and efficacious use of pain medications is also warranted.
References
Footnotes
Disclaimer This consensus paper provides an overview of pain management issues in elite athletes that are important to physicians and other clinicians who treat elite athletes. It is not intended as a clinical practice guideline or legal standard of care and should not be interpreted as such. This consensus paper serves as a guide and, as such, is of a general nature, consistent with the reasonable practice of the healthcare professional. Individual treatment will depend on the facts and circumstances specific to each individual case.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.