List of Tables
1: The Problem of Neck Pain
Introduction
This chapter provides background information about neck pain and its impact on the general population. Modern clinical epidemiology is concerned with the distribution, natural history and clinical course of a disease, risk and prognostic factors associated with it, the health needs it produces and the determination of the most effective methods of treatment and management (Streiner and Norman 1996). A brief overview of these dimensions as related to neck pain is provided.
Sections are as follows:
prevalence
• natural history severity and disability health care-seeking risk factors
onset
• prognostic factors cost
treatment effectiveness.
Prevalence
The epidemiology of neck pain in the adult population has been less thoroughly investigated than lumbar back pain, but there is still a reasonable amount of literature upon which to draw. Population
based studies give the best indication of the rates of a problem in the community, and their findings are displayed in Table 1.1. Sampling methods, response rates and definitions have varied between studies and may explain some of the differences in results. Nonetheless the surveys generally reveal the common nature of neck pain, although we cannot be sure of the exact prevalence rate in the population.
The role that definition of pain site has in altering prevalence figures is illustrated by one study that gave year prevalence of neck pain as
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CHAPTER. ONE THE CER.VICAL & THORACIC SPINE: MECHANICAL DIAGNOSIS & THERAPY31 % and neck-shoulder-higher back as 44.5% (Picavet and Schouten 2003). In a postal survey it is not possible to confirm the anatomical origin of these symptoms.
Lifetime prevalence of neck pain was about 70% in two studies. Point, month and year prevalence range in a number of studies, between 12% and 41 % of the general population (Table 1.1).
Table 1.1 Prevalence of neck pain in general population studies
Point/month 6m-ly* Lifetime Reference Country prevalence prevalence prevalence
Hasvold and Johnsen Norway 20%
1993
Makela et al. 1991 Finland 41% 71%
Bovim et al. 1994 Norway 34%
Cote et al. 1998 Canada 22% 67%
Lock et al. 1999 UK 21%
Leclerc et al. 1999 France 41%
Takala et aL 1982 Finland 17%
Westerhng and Jonssen Sweden 12% 18%
1980
Urwin et aL 1998 UK 16%
Picavet and Schouten Netherlands 21% 31%
2003
Bassols et al. 1999 Spain 22%
Linton et al. 1998 Sweden 44%
Hagen et al. 1997a Norway 15%
Cote et al. 2004 Canada 53%
Mean 21% 31% 69%
* six month or one year prevalence
The annual incidence of neck pain, defined as a new episode during a follow-up year in those free of neck pain at baseline, has been estimated to be 15% to 19.5% in three population studies (Leclerc et al. 1999; Croft et al. 2001; Cote et al. 2004). Although these studies reveal the common nature of these pain complaints in the general adult population, they do not tell us about persistence of symptoms, severity, or what impact neck pain has on people's lives.
THE PROBLEM OF NECK PAIN
Natural history
A number of studies suggest that, like lumbar back pain, the natural history of neck pain is frequently protracted and episodic. In two long-term follow-ups of over 250 patients with neck pain, nearly 60% reported on-going or recurrent problems (Lees and Turner 1963;
Gore et al. 1987). In those who had on-going symptoms , just over half reported them to be moderate or severe (Gore et al. 1987). Retrospec
tively, 42% of a general population sample of nearly four thousand reported an episodic history of neck-shoulder-brachial pain (Lawrence 1969). About one-third of patients with cervical radiculopathy have reported aL least one previous episode (Radhakrishnan et al. 1994).
In a study of nearly seven hundred individuals followed over a year, 40% reported neck pain on two occasions (Leclerc et al. 1999). A twelve-year follow-up study found only 4% of those initially sick-listed for neck pain to be pain-free, whereas 44% reported themselves to be the same or worse than they had been twelve years earlier (Kjellman et al. 2001). In a follow-up study of nearly eight hundred individuals who reported neck pain at baseline, 48% reported symptoms one year later (Hill et al. 2004). These reports all suggest that at least 40% of those who report neck pain will have a history of relapse and future episodes - very similar to the relapse rate reported in long-term studies of lumbar back pain patients (McKenzie and May 2003).
Equally, reports of persistent and long-term pain prolonged over many months are found amongst those with neck pain, just as in the lumbar back pain population (Table 1.2). Again, the difficulty of determining the origin of symptoms felt around the neck-shoulder-upper back region makes figures imprecise. Depending on whether the definition of neck pain is limited or inclusive, the average of these figures suggests between 16% and 23% of the adult general population suffer from persistent neck pain of at least three months' duration.
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CHAPTER. ON E THE CERVICAL & THORACIC SPINE: MECHANICAL DIAGN OSIS & THERAPYTable 1.2 Prevalence of persistent neck pain in general population
ReJerence Country Neck pain Jar> 3 months
Andersson et al. 1993 Sweden 17%
30% (Neck-shoulder area)
Brattberg et al. 1989 Sweden 19%
Bergman et al. 2001 Sweden 19%
Picavet and Schouten Netherlands 14%
2003 36% (Neck, shoulders,
higher back)
Makela et al. 1991 Finland 11%
Hill et al. 2004 UK 48%*
Cote et al. 2004 Canada 47%
Guez et al. 2003 Sweden 18%
Mean 26%
* persistent pain defined as chronic, recurrent or continuous In over a thousand individuals, just over half of whom had neck pain at baseline, 15% developed new neck pain and 70% had persistent, recurrent or worse neck pain at one year (Cote et al. 2004). Amongst those who reported neck-shoulder-higher back pain, only 6% reported a Single non-recurrent episode, 39% reported continuous pain and 55% reported recurrent symptoms (Picavet and Schouten 2003). It is clear that the natural history of neck pain is similar to that of back pain and is often persistent or recurrent.
Severity and disability
The last study also reported on symptom severity. In those with continuous or recurrent pain (84%), 11 % reported this to be severe, but a further 10% reported severe episodes against a background of mild continuous pain (Pica vet and Schouten 2003). A minority (6%) reported partial disability from work and work leave greater than four weeks due to neck symptoms; however, while 29% reported some limitation of daily living, the majority (80%) reported no or minimal work loss (Picavet and Schouten 2003). High disability attributed to neck pain appears to affect the minority (< 10%) of those with symptoms (Figure 11). Combined neck and arm pain have been reported as much more disabling than either symptom alone (Daffner et al. 2003).
THE PROBLEM OF NECK PAIN
Figure l.1 Severity and disability grading of neck pain (N = 1100)
600 500
� 400
'"
.D E 300
i 200
100 o
Grade 0 � no pain, no disability Grade 1 � low intensity, low disability Grade 2 � high intensityllow disability Grade 3 � high disability/moderately limiting Grade 4 � high disability/severely limiting Source: COle et al. 1998
Health care-seeking
As with those who have lumbar back pain, not everyone with neck pain seeks health care. In the Netherlands, just over 50% of those with neck-shoulder-upper back pain had contact with a Gp, specialist or physiotherapist (Picavet and Schouten 2003). In the US, in two studies with a mixed population of neck andJor back pain, 25% to 66% had sought health care from a complementary or conventional provider (Cote et al. 2001; Wolsko et al. 2003). In the UK, 69%
consulted a health professional, mostly their GP or, less commonly, a physiotherapist (Lock et al. 1999).
Clearly not everyone with neck problems seeks treatment, but because of the high prevalence rate in the general population, neck pain patients feature prominently in health care services. Of 6,526 patients visiting GPs in Finland during a two-week period, 27% of those over the age of fifteen had musculoskeletal problems (Rekola et al. 1993). Twenty per cent of them had neck pain, compared to 18% with back pain, which represented over 4% of all GP consultations. In a survey of over 1,700 patients in primary care phYSiotherapy clinics in the UK, 22% had neck pain (May 2003).
Risk factors
Risk factors are variables that are associated with a greater chance of acquiring the condition of interest; in this case, neck pain. There are numerous studies that have tried to identify risk factors that are
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CHAPTER ON E THE CERVICAL & THORACIC SPINE: MECHANICAL DIAGNOSIS & THERAPYassociated with neck pain, and several reviews are available (Bongers et al. 1993; Ariens et al. 1999; Vingard and Nachemson 2000). Studies tend to evaluate individual risk factors, physical and psychosocial work-related factors and non-work-related factors. Most studies address only a few risk factors, or only one type of risk factor, and do not account for other types of risk factors. This over-inflates the role of variables being considered and ignores variables that are not included in the analysis. Most studies are cross-sectional in nature, recording risk factor and outcome (neck pain) at the same time. This may reveal an association between the factor and pain, but does not confirm a causal link. Prospective study designs are more costly and complicated, but can more clearly establish a causal relationship as they are conducted in a cohort followed over time.
Individual factors associated with neck pain are female sex, increasing age up to about 50 when the risk declines, and history of previous neck pain. As already noted in the section on natural history, previous neck pain is a potent risk factor for further symptoms, especially for persistent neck pain (Leclerc et al. 1999; Croft et al. 2001). Most studies report higher prevalence rates of neck pain in women than men (Webb et al. 2003; Croft et al. 2001; Leclerc et al. 1999; Cote et al. 1998; Makela et al. 1991; Hasvold and Johnsen 1993; Andersson et al. 1993; Westerling andJonsson 1980). Several studies found the prevalence of neck pain increases with age, at least until about 50 to 60 years of age, after which symptom reporting seems to decline (Hasvold and Johnsen 1993; Makela et al. 1991; Lock et al. 1999;
Takala et al. 1982; Andersson et al. 1993; Kramer 1990). Weak associations have been found between smoking, obeSity, low-pressure pain thresholds and neck pain (Makela et al. 1991; Cote et al. 2000;
Andersen et al. 2002)
Comorbities have been associated with neck pain, namely other pain problems such as headache (Leclerc et al. 1999), lumbar back pain and previous neck injury (Andersen et al. 2002; Croft et al. 2001), but also digestive and cardiovascular problems (Cote et al. 2000). Other studies also suggest an association between neck pain and pain in other sites (Webb et al. 2003; Rekola et al. 1997; Kjellman et al. 2001).
Some studies identified psychosocial factors that are associated with neck pain, but many studies have found no association (Bongers et al. 1993; Ariens et al. 1999; Vingard and Nachemson 2000).
Psychological distress has been associated with neck pain (Leclerc
THE PROBLEM OF NECK PAIN
et al. 1999; Makela et al. 1991; Croft et al. 2001). Barnekow-Bergkvist et al. ( 1998) found risk factors varied between men and women.
Among men, self-employment and worry were associated with neck
shoulder symptoms; amongst women, monotony and control at work.
Lower educational level, lower household income and raised material deprivation had some association with neck pain (Makela et al. 199 1;
Cote et al. 2000; Webb et al. 2003) There was no relationship between work satisfaction and neck pain, but high job satisfaction had a protec
tive effect (Leclerc et al. 1999). High perceived job demands and low social support at work were associated with neck pain (Andersen et al.
2002; Ariens et al. 2001a). The latter was a prospective study design that adjusted for physical and individual characteristics, and thus had a strong study design (Ariens et al. 2001a). In a life-long prospective study, psychosocial factors in childhood were unimportant predictors of neck pain as an adult (Viikari-Juntura et al. 1991).
Physical work factors have also been shown to have a relationship with neck pain, although not all studies are consistent in their findings (Ariens et al. 1999). Reviews found various studies strongly corre
lated neck pain with work in static postures, such as typists, visual display workers and sewing machine operators (Grieco et al. 1998;
Vingard and Nachemson 2000). Heavier work, repetitive work, force and neck flexion have been associated with neck pain (Makela et al.
199 1; Andersen et al. 2002). Several other studies have found an association between neck flexion and neck pain (Dartigues et al.
1988; Kilborn et al. 1986; Ignatius et al. 1993). Seven studies looked at the association between sitting and neck pain: four found a weak association and three found no significant relationship (Ariens et al. 1999) However, in a study with a strong deSign, a positive independent association was found between sitting and neck pain, and between neck flexion and neck pain (Ariens et al. 200 1b). This was a prospective study taking into account other confounding physical, psychosocial and individual factors.
Two studies have looked specifically at factors associated with prolapsed cervical intervertebral disc disease (Kelsey et al. 1984;
Jensen et al. 1996). Frequent heavy lifting, cigarette smoking and diving were associated with the diagnosis in one study (Kelsey et al.
1984). Jensen et al. ( 1996) found that all men in occupations involving professional driving had an elevated risk of being hospitalised with prolapsed cervical intervertebral disc.
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CHAPTER ON E THE CERVICAL & THORACIC SPINE: MECHANICAL DIAGNOSIS & THERAPYIt is clear that there are a wide range of factors that may be potential risk factors for the onset of neck pain, The literature is generally poor quality, mostly consisting of cross-sectional studies from which a causal link between a factor and neck pain cannot be concluded, Some higher-quality studies with a prospective study design and adjusting for other potential risk factors have been conducted more recently It is likely that physical load factors such as neck flexion, sitting and static postures and psychosocial factors at work are important predictors of neck pain, The present literature would support earlier suggestions that prolonged sitting and frequency of neck flexion are predisposing factors for neck pain (McKenzie 1981),
Onset
Commonly, a sudden or insidious onset of neck pain is reported (McKenzie 1981; Kramer 1990), This would suggest that normal daily mechanical loading might frequently trigger neck pain symptoms, Kramer (1990) reports that symptoms are brought on by prolonged kyphotic posture during reading or deskwork, by rotational move
ments, or, so patients report, from sitting in a draft Equally sustained loading during sleep may trigger symptoms, In a random population
based study, about 20% reported commonly waking with scapular, arm or neck pain, headache or neck stiffness (Gordan et aL 2002),
Neck pain can also be triggered by traumatic onset, most commonly whiplash-type injuries, See Chapter 25 for relevant materiaL However, it is important to bear in mind the insidious onset of much neck pain as this alerts the clinician to mechanical loading factors that may be implicated in predisposing, precipitating and prolonging a patient's neck pain,
Prognostic factors
Prognostic factors are variables that affect the outcome of an episode of neck pain once it has started, The literature in this area is limited, and in reviews of the topic (Borghouts et aL 1998; Ariens et aL 1999) only six relevant studies, generally of poor quality, were found, Several reports were contradictory about the effect of age or gender on outcome, and arm pain and radiological findings were not associated with prognosis, However, severe initial pain and a history of previous episodes seemed to indicate a worse outcome,
THE PROBLEM OF NECK PAIN
Several recent cohort studies have identified items from the neck pain history and comorbidities as prognostic factors. High initial pain and functional disability scores, long duration of current episode, previous episodes o[ neck pain, lowered well-being and limited patient expecta
tions of treatment have predicted poorer outcomes at twelve months (Kjellman et al. 2002). Older age (> 40) and concomitant low back pain have predicted a poorer outcome both short- and long-term, and trauma, long duration and previous history of neck pain have predicted poorer outcome long-term ( Hoving et al. 2004). In a large population study, nearly eight hundred reported neck pain at baseline and were followed for a year when 48% reported chronic, recurrent or continuous neck pain ( Hill et al. 2004). Significant baseline char
acteristics that predicted persistent neck pain were older age (> 45, especially 45 to 59), being off work at baseline, comorbid back pain and cycling as a regular activity.
Cost
In the Netherlands the total cost of neck pain in 1996 was estimated to be US$686 million (Borghouts et al. 1999). Of this, 23% was spent on direct medical costs, mostly physical therapy, whereas 77%
was absorbed by societal non-medical costs. This compared to an estimated cost of US$4,968 billion for back pain in the Netherlands in 1991 (van Tulder et al. 1995).
Treatment effectiveness
As with lumbar back pain, a wide range of treatment interventions are offered to patients with neck pain. These interventions have not appeared to affect the underlying prevalence or recurrence rates.
A number of systematic reviews have been undertaken to evaluate the treatment effectiveness of interventions for neck pain, and their conclusions are summarised here.
Evidence does not support the use of acupuncture for chronic neck pain; of eight high-quality trials, five were negative (Kjellman et al.
1999; White and Ernst 1999). Subsequent trials have demonstrated short-term changes in pain, but outcomes no better than sham treatment (Irnich et al. 2001, 2002) or not clinically Significantly better than placebo (White et al. 2004). High-quality studies demon
strated lack of effect [or traction (Kjellman et al. 1999; Philadelphia
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CHAPTER ONE THE CERVICAL & THORACIC SPINE: MECHANICAL DIAGNOSIS & THERAPYPanel 2001). Data regarding the use of ultrasound, TENS, massage, electrical stimulation and other electrotherapy modalities or heat therapy is either lacking, limited or conflicting (Philadelphia Panel 200 1; Kroeling et al. 2005).
At present there is little scientific evidence to support the effective
ness o f multidisciplinary biopsychosocial rehabilitation programmes (Karjalainen et al. 2001).
Several reviews have provided limited to moderate support in favour of the short-term benefits o f mobilisation and/or manipulation for some types of neck pain and/or headaches (Aker et al. 1996; Hurwitz et al. 1996; Kjellman et al. 1999; Bronfort et al. 200 1, 2004). However, Di Fabio (1999) considered that the literature does not demonstrate that the benefits of manipulation outweigh the risks that are involved.
Recent reviews (Gross et al. 2002, 2004) concluded that manipulation and/or mobilisation had no better effect than placebo or control groups and were equal when compared to each other, but done alone neither were beneficial. However, when manual therapy was combined with exercise, results were superior to control groups. To be of clear benefit, manual therapy, it seems, must be combined with exercise.
Several reviews have commented on the effectiveness of exercises for neck pain (Kjellman et al. 1999; Sarig-Bahat 2003). The Philadelphia Panel on Evidence-Based Clinical Practice Guidelines concluded that therapeutic exercise was the only intervention with clinically important benefits relative to a control (Philadelphia Panel 2001).
When exercise has been compared to mobilisation or manipulation plus exercise, both groups showed similar improvements (Gross et al. 2004). This last review "shows that it does not matter what hind of passive treatment one offers, it is what the patient does that really matters" (Mailis-Gagnon and Tepperman 2004).
Hoving et al. (2001) identified and examined twenty- five reviews, of which twelve were systematic, but all these were from the 1990s.
Conclusions lacked agreement about mobilisation, acupuncture and drug therapy, but agreed that the evidence was inconclusive on the e ffectiveness o f manipulation and traction.
This brief summary of the literature, despite its limitations, would suggest certain conclusions about the management o f neck pain that concur with management gUidelines about low back pain. The range
THE PROBLEM OF NECK PAIN
of passive therapies offered to neck pain patients may provide some limited short-term pain relief at best, but most have failed to demon
strate any useful long- or even short-term benefit. For a wide range of passive therapies still being dispensed by clinicians on a regular basis, there is scant supportive evidence.
For more active treatments the evidence is more positive. Exercise appears to be effective. Manual therapy may be effective when
For more active treatments the evidence is more positive. Exercise appears to be effective. Manual therapy may be effective when