Trapezius Myalgia

Top Contributors - Nick Van Doorsselaer, Lauren Trehout, Abbey Wright, Elien Clerix, Camille Dewaele, Gayatri Jadav Upadhyay, Kim Jackson, Vanessa Rhule, Admin, Joao Costa, Rachael Lowe, Aminat Abolade, Rishika Babburu, Ajay Upadhyay, Kai A. Sigel and Kirenga Bamurange Liliane  - Simon Vanelewijck - Roel Kelderman

Definition/Description

Myalgia is generally known as muscle ache or muscle pain.

Trapezius myalgia (TM) is the complaint of pain, stiffness and tightness of the upper trapezius muscle. It is characterised by acute or persistent neck-shoulder pain.
TM is not a medical disorder or disease but rather a symptom of an existing underlying condition. The pain in the muscle can last a few days or longer.

Clinically Relevant Anatomy

The trapezius muscle is a large trapezoid shaped muscle that makes up most of the superficial posterior cervical and thoracic musculature and consists of three parts

‐ Trapezius pars descendens (superior part)
‐ Trapezius pars transversa (middle part)
‐ Trapezius pars ascendens (inferior part)

The visualisation of the course, functions and innervation of all three parts is shown in the following video:
https://www.youtube.com/watch?v=P5sOhwBZon8 
In TM it is the superior part that is painful¹.This part originates from the linea nuchalis superior, the protuberantia externa and through the nuchal ligament from all cervical spinous processes. The insertion is on the lateral third of the clavicula and the acromion⁴.

All parts work together to stabilize the scapula⁵ . The superior fibers are responsible for upward rotation and elevation of the scapula, homolateral lateroflexion and heterolateral rotation of the head. When activated bilaterally, the superior part ensures neck extension⁴. 

Etiology/Epidemiology 

There has been a lot of research on the etiology of work related neck and shoulder disorders and hence of TM. Researchers agree that the disorders arise from both biomechanical and psychosocial factors. There are no clear differences in muscle morphology and physiology between subjects with trapezius myalgia and healthy controls. Further research is needed. [1]
Monotonous jobs with highly repetitive work, forceful exertions, high level of static contractions, prolonged static loads, constrained work postures or a combination of these factors are possible causes of neck and shoulder disorders (which include TM) in the working population. [1][6] More research is required to conclude that computer work alone increases the risk of developing musculoskeletal disorders. [11]
Centrally a reorganization of the neuromotor control strategies takes place. The superficial cervical extensor muscles show a higher muscle activation and deplete faster. So, the superficial upper trapezius shows a higher activation than the erector spinae. A greater recruitment of type II fibers in symptomatic patients could possibly explain the muscle fatigue. [10]
Furthermore, there is a relation between psychosocial factors and the occurrence of neck and shoulder disorders. There is some evidence that there is a link between disorders and high quantitative and qualitative demands, lack of support of colleagues, low job control and low influence. There is also a link between mental stress at work and disorders. However, the limited amount of literature focusing on causal relationships between psychosocial factors and disorders makes it difficult to estimate the influence of these factors and how they may interact with the biomechanical and individual factors. [6]
Epidemiology
Most epidemiological studies are about neck-shoulder disorders in general. Trapezius myalgia belongs to these kind of disorders and therefore belongs to 20-30% of the estimated prevalence of upper-extremity symptoms in the working population.
Gender seems to play an important role in the development of neck disorders, since the prevalence is much higher among women. Women more often experience neck pain and develop persistent pain than men do. This difference might be explained by the content of their jobs. Women’s work tasks involve more static load on the neck muscles, high repetitiveness, low control and high mental demands, which are all risk factors for developing neck disorders ( see ‘etiology’). [6]
Chronic TM concerns 10-20% of the 20% of the adult population with severe chronic pain in the neck and shoulder region. [7] The chronic form of TM also shows a higher prevalence in women, but also in low income groups7. [12].

Characteristics/Clinical Presentation

Typical symptoms of “myalgia” are [13]:
- sudden onset of (severe) pain that lingers for a few days to weeks. The pain is associated with stiffness and spasms
- heaviness of the head and occipital headache
- tenderness of the affected area
Other symptoms [13]:
- nausea and vomiting
- onset of fever
- anxiety and depression
- stiffness of the affected muscle
- vertigo
- numbness and tingling sensations
In case of acute myalgia, the patient can be severely incapacitated because of the pain. Chronic myalgia typically causes pain and stiffness after periods of inactivity. The pain usually eases after reasonable exercise. [13]
The clinical presentation consists of pain, spasms and tenderness in the upper trapezius. Trigger points in the muscle can cause painful headaches behind the eye, into the temple and in the back of the neck. [6][14]

Differential Diagnosis

According to the review of Larsson et al.⁶ TM can only be diagnosed when neck pain, muscle tightness and trigger points are present, but tension neck syndrome or cervical syndrome is not present.

Tension neck syndrome shows the same symptoms, with the pain radiating from the neck to the back of the head and an additional sense of fatigue or stiffness in the neck. In cervical syndrome the pain radiates from the neck to the upper extremity, there is also decreased sensibility in hands and fingers and muscle weakness in the upper limb.

Other pathologies that can cause similar symptoms are:
- Cervicalgia: neck pain and limited mobility in at least four directions⁶
- Thoracic Outlet Syndrome: pain in the neck, trapezius region, supraclavicular region, chest and occipital region and paresthesia in the upper extremity ⁶

Diagnostic Procedures

The review of Larsson et al.⁶ confirms that the basis for diagnostic criteria of neck and shoulder myalgia is not very clear and that the diagnostic terminology and methods for assessment are variable. If the progressing neck and shoulder pain isn’t accompanied by other symptoms or signs (cfr. red flags), specific investigations such as radiography, magnetic resonance imaging, electromyography or nerve conductance testing aren’t required.

When there’s dubiety between several conditions, certain medical tests¹⁵  are helpful to eliminate certain diagnoses. Radiography and MRI eliminate bone or joint disorders, a blood test can detect inflammation and therefore eliminate underlying conditions that may cause muscle disorders. Electromyography can differentiate between a muscle or nerve disorder if one is present. For the diagnosis of inherited metabolic disorders, connective tissue disease, eosinophilia-myalgia, sarcoidosis and trichinosis, muscle biopsy is indicated.

In general, no objective diagnostic methods are available. The diagnosis is mostly based on symptom presentation and history of illness.^{2 15}

Outcome measures

Visual analogue scale¹
This scale measures visualizes to what extend the patient experiences pain or another sensation. It is a 100mm line on which the patient need to draw a perpendicular line to indicate how he experiences pain. On the left is the minimum score of 0 meaning ‘no pain’ and on the right, stands the maximus score of 10, which means ‘unbearable pain’.

Pain thresholds
In the study of Waling et al.[51] the pain of the patient is measured in six trigger points (see figure 51). These points were selected by Simons and Travell (1893)16 . The pain is measured with a pressure algometer, showing the applied pressure in kPa and indicating the rate of pressure increase. The patient has to indicate when the given sensation starts to hurt. This is the pain threshold. If the therapy is successful, the pain threshold should be higher, so it takes longer for the patient to experience a sensation as pain.

Figure 51; triggerpoints

Pain drawing¹
The pain distribution and the characteristics of the pain are marked on a drawing of a body. The total body area marked as painful is interpreted as a percentage of the body area.
Margolis et al.¹⁸ created a method to calculate the percentage of painful body area.

McGill pain questionnaire¹⁹
The MPQ is a subjective questionnaire used to asses the quality and intensity of pain in patients with a number of diagnoses.

Neck disability index  ^{20 21}
The NDI is a questionnaire that inquires the functional status of a patient concern the following 10 items: pain, personal care, lifting, reading, headaches, concentration, work, driving, sleeping and recreation.

Neck Bournemouth Questionnaire ^{22 23}
The NBQ is administered to patients with non specific neck pain. It assesses pain, disability, affective aspects and cognitive aspects of the neck pain. The questionnaire contains seven items: pain intensity, function in activities of daily living, function in social activities, anxiety, depression levels, fear avoidance behavior. The NBQ has been shown to be reliable, valid, and responsive to clinically significant change in patients with nonspecific neck pain.

PSFS

Examination

A standard clinical examination of the neck and upper extremities can be useful for diagnosing TM, because there is no specific examination to diagnose TM. The examination consists of questionaries’ about neck pain, headache, tiredness, stiffness, physical tests including range of motion (ROM) and muscle tightness, pain provocation movements, sensibility, strength and palpation of trigger points.^{6 31}

Patients suffering from TM usually have neck pain, headache, tightness of the trapezius muscle usually in the upper part and palpable trigger points in the trapezius muscle (see also figure 51). ^{31 32}

A surface electromyography can be done to evaluate muscle function. Parameters that can be studied are amplitude, timing, conduction velocity, fatigability and characteristic frequencies/patterns.³³

In cases where a typical anamnesis with progressing neck and shoulder pain and no other symptoms or signs is mentioned and where a clinical examination can confirm the diagnosis, there is no need for supplementary objective investigations such as a surface electromyography.⁶ But the study of Juul-Kristensen et al. [LoE: 3B] found that for 60% of those with self-reported neck symptoms of a certain duration and intensity, a clinical examination can confirm one or more diagnoses, with trapezius myalgia (38%), tension neck syndrome (17%), and cervicalgia (17%) being the most frequent. But in the other 40% a supplementary objective investigation is needed to make a correct diagnosis.⁴⁹

Medical Management

There is no specific medical management for TM. This is because either TM is caused by environmental reasons like stress, overuse, bad working position… or either it’s a side effect of different kinds of medication.
With medication, you can only treat the pain, but not the cause.

According to the review of Jensen et al most of the pharmacological treatments lack effects or haven’t enough evidence. An intra-muscular injection with lidocaine only has short term effect on pain in chronic neck pain. Intravenous methylprednisolone and lidocaine works in short term on pain. There is not enough evidence on the long term effects of surgical interventions.  ²⁴

Physical Therapy Management

Prevention
Electromyographical biofeedback training of the upper trapezius muscle might be useful in the prevention of TM in computer workers. (LoE:1B) Studies have found a positive relation between the amount of inactivity and neck disorders. Sedentary workers with low levels of leisure-time activity had a higher prevalence of neck disorders.From this we can conclude that it is important to be active after working hours.The biggest risk factors are:

• repetitive movements, gender (woman),
• high force demands,
• work posture,
• vibration,
• computer work and stress.

Information and advice
To prevent TM it’s important to inform people who are at risk about what they should or shouldn’t do. We need to advise them on which working position is the best and how to work at the computer.Stress management :Stress is a big risk factor for developing trapezius myalgia. Therefor it should be a main focus in prevention and treating TM. With stress often comes muscle tension in the upper part of the trapezius. This should be avoided and decreased. Physical applications:There is moderate evidence available for short-term relief of mysfascial trigger points by Transcutaneous Electro Nerve Stimulation (TENS), acapuncture and magnet therapy. Laser therapy and acupuncture also show symptom relief of myofascial trigger points.The review of Chow et al. shows evidence of pain reduction in patients with acute or chronic neck pain after low-level laser therapy (wavelength: 780, 830 or 904 nm.. (LoE:1A

however there are other studies that say The quality of evidence ranged from very poor to poor in short term with acupuncture/dry needling having the largest effect size. There is  no evidence of effective treatment to reduce pain in the intermediate and long term periods. (LoE:A1)

The RCT of Aguilera et al shows an immediate decrease in electrical activity in the trapezius muscle and a reduced sensitivity of myofascial trigger points after ultrasound treatment. The review of Vernon & Schneider show however that there’s conflicting evidence (level C) as to whether ultrasound therapy is no more effective than placebo or somewhat more effective than other therapies in the treatment of myofascial trigger points. Ultrasound can therefore be used as a therapeutic modulation, but is not recommended.

Biofeedback, earlier described as a prevention modality, can also be useful in the treatment of work related neck-and shoulder pain. The RCT of Ma et al. shows that six weeks of biofeedback training results in less pain and neck disability than active and passive treatment, which is remained at 6 months pos tintervention. They also found consistent trends of reduced muscle activity in the upper trapezius.(LoE:1B)

however there are other studies that say The quality of evidence ranged from very poor to poor in short term with acupuncture/dry needling having the largest effect size. There is  no evidence of effective treatment to reduce pain in the intermediate and long term periods. (LoE:A1)

Manual therapies
Ischemic compression, stretch of the upper trapezius muscle, transverse friction massage are manual techniques to help patients with TM. These techniques appear to have instant improvement on pain. Long-term effects have not yet been well investigated.The RCT of Aguilera et al. shows an immediate decrease in electrical activity in the trapezius muscle and an improvement of active ROM after ischemic compression.According to Vernon & Schneider moderatly strong evidence (level B) is available for immediate pain relief at trigger points due to spinal manipulation and ischemic compression.

Physical exercise
Different forms of exercise can be recommended for acute or persistent neck pain (LoE:5)

Physical activity and exercise have been proven to give the most immediate and long-term pain relief in patients with TM. Both general fitness training and specific strength training generate significant effects on decreasing pain(LoE:2B). However strength training has proven to be even more effective compared to general fitness training. Following a specific neck strengthening exercise program a study showed that three years later the neck strength gains were consistent despite a similar NDI score to one year after completing the program. Therefore; pain and strength were maintained even after adherence to the exercise program faltered after the initial year.(LoE:2B)

High-intensity strength training relying on principles of progressive overload for 20min can be successfully in reductions of neck and shoulder pain
(LoE:1A),(LoE:1B),(LoE:1B)

A study showed that general exercise is beneficial for TM pain. Especially specific strengthening exercises however it was also shown that general fitness exercise can reduce pain. (LoE:2B)

1. Shoulder shrugs:
The subject is standing erect and holding the dumbbells to the side, then elevates the shoulders while focusing on contracting the upper trapezius muscle.

2. One-arm row:
The subject is bending her torso forward to approximately 30° from horizontal with one knee on the bench and the other foot on the floor. The subject now pulls the dumbbell towards the ipsilateral lower rib, while the contralateral arm is maintained extended and supports the body on the bench.

3. Upright row:
The subject is standing erect and holding the dumbbells while the arms are hanging relaxed in front of the body. The dumbbells are lifted towards the chest in a vertical line close to the body while flexing the elbows and abducting the shoulder. The elbows are pointing out- and upwards.

4. Reverse flyes:
The subject is lying on the chest at a 45° angle from horizontal and the arms pointing towards the floor. The dumbbells are raised until the upper arm is horizontally, while the elbows are in a static slightly flexed position (~5°) during the entire range of motion.

5. Lateral raise:
The subject is standing erect and holding the dumbbells side, and then abducts the shoulder joint until the upper arm is horizontally. The elbows are in a static slightly flexed position (5°) during the entire range of motion.

Exercise has been shown to increase blood flow and therefore oxygenation to areas of the body with increase anaerobic muscle metabolism. (LoE:2B)

Psychosocial involvement
The possible presence of psychosocial causative factors in patients with TM should be considered. If they are present, the patient should certainly be approached biopsychosocially.

Resources 

Bournemouth Neck Questionnaire

Short form McGill pain questionnaire

Neck Disability Index

Myalgia definition

Clinical Bottom Line

In a study of patients with and without pain but exposed to repetitive load such as desk work showed increased muscle fiber cross sectional areas - however it is unclear how this relates to pain.

A EMG and doppler flowmetry study concluded that patient's with TM have impaired microcirculation in the upper traps which it is hypothesized can lead to nocieptive pain patterns. A further EMG study in the non-painful population showed higher trapezius activity in the dominant hand and more trapezius activity in men than women. Again after exercise in patients with pain EMG studies have shown nocieptive patterns (increased anaerobic metabolism) in comparison with a control group. Trapezius biopsy also shows increase in inflammatory proteins compared with control group.

Trapezius Myalgia is rather a symptom of an underlying existing problem than the problem itself and is often categorized in the neck and shoulder disorders. The typical symptoms of a patient with TM complaints are pain in the upper trapezius muscle that can linger for a few days to weeks. This pain is often associated with spasms, stiffness and tenderness in the neck region with radiation to the head and behind the eyes. Trigger points can also be present and can cause headaches. Both biomechanical and psychosocial factors can contribute to the development and maintenance of TM. It should be kept in mind that women suffer more frequently of TM than men do.
TM shouldn’t be confused with the tension neck syndrome, cervical syndrome, cervicalgia or thoracic outlet syndrome. To differentiate between these pathologies, the anamnesis and addition standard clinical examination on neck and upper extremities are very important. The use of a VAS for pain, a pressure algometer, a pain drawing and several questionnaires focused on pain and disabilities could help to evaluate the success of the treatment. Radiography, MRI, electromyography, nerve conductance testing or blood tests could be done to rule out other disorders, but aren’t standard procedures. The medical treatment consists of painkillers, which is the only medication which helps at short-term. The physiotherapist can apply TENS, dry needling, magnet therapy, laser therapy and ultrasound for short-term relief of the myofascial trigger points. Laser therapy, dry needling and biofeedback training can also result in a long-term effect. Biofeedback training is also a precautionary measure. Ischemic compression and dry needling are manual techniques which could be used to relieve the pain of the trigger points immediately. Also stretch of the upper trapezius muscle and transverse friction massage are pain mitigation techniques. General fitness training appears to relieve pain immediately while 3 times a week 20 minutes’ specific strength training of the neck and shoulder musculature at an intensity of 70-85% relieves pain at long term. To avoid or cure TM it’s important to be active during the day and prevent overuse of the trapezius or stress.