Free Web Tip On Musculoskeletal Disorders (MSD)

“MSDs account for 42 per cent of all lost time claims accepted by the Workplace Safety and Insurance Board (WSIB), 42 per cent of all lost time claim costs and 50 per cent of all lost time days (averages for 1996 – 2004).”

– OHSCO, 2013


What is an MSD?

Musculoskeletal disorders impact the musculoskeletal system, which includes the muscles, tendons, ligaments, discs, blood vessels, and nerves (Occupational Health and Safety Council of Ontario [OHSCO], 2013).

 What is a WMSD?

A Work-related Musculoskeletal Disorder is an MSD, which is caused or exacerbated by environmental or job-related factors in the workplace (WSIB). WMD’s are considered a workplace health and safety issue because they are closely connected to workplace hazards. Employers are therefore legally required to make their workers award of these risks and take every reasonable precaution to protect their staff from MSD’s (OHSCO, 2013).

Most work involves the use of the upper extremities (arms and hands). Understandably, these are therefore the common locations for WMSD’s to occur, often impacting the hands, wrists, elbows, neck, and shoulders. If work is more commonly using the lower extremities, it is also possible to develop WMSD’s in the legs, hips, ankles, and feet (CCOHS, 2005)

What Causes an MSD? (OHSCO, 2013 & CCOHS, 2005)

Many factors can increase the likelihood of MSD development which include:

  • Force (especially when focused on small body parts such as the wrist)
  • Awkward posture
  • Static body posture
  • Repetition
  • Long duration
  • Pace (if it does not allow sufficient recovery time between movements)
  • Temperature (heat or cold)
  • Vibrations

MSD’s often occur as a result of a combination of these factors occurring simultaneously, not individually.

 WMSD Symptoms: (CCOHS, 2005)

  1. PAIN= the most common
  2. Joint stiffness
  3. Muscle tightness
  4. Redness of area
  5. Swelling of impacted area
  6. Pins and needles sensation
  7. Numbness
  8. Skin colour change
  9. Decreased sweating of the hands

These symptoms may occur concurrently or independently in a range from mild to severe. In an early stage, an employee may feel aching and tired feelings of the impacted limb while working only and would not experience any change in their levels of performance. In an intermediate stage, the worker would have similar aching and tiredness, but it would continue when they were not working and would influence their repetitive work capacity. In a late sate, weakness, fatigue, and aching would persist in a resting state and would impact the workers ability to sleep and complete light duties.

WMSD Treatment (CCOHS, 2005)

There are many different options for WMSD treatments, some of the most common include:

  • Restriction of movement
  • Application of heat or cold
  • Exercise
  • Medication and surgery

WMSD Prevention 

A fundamental principle of occupational health and safety is to eliminate hazards at their source. Ergonomics and provision of a solid erognomic risk assessment of the work duties can reduce the hazards.

Common workplace hazards for WMSD’s were previously stated, and can be altered or avoided through changes in job designs. Different elements of job design that an employer can alter includes:

  • Mechanization
  • Job rotation
  • Job enlargement and enrichment (increase task variety)
  • Team work
  • Workplace design
  • Tool and equipment design
  • Work practices (actual performances and worker habits

Common Musculoskeletal Disorders

The following MSD’s are explored in detail in this Webtip:

  • Tendonitis & Tenosynovitis
  • Epicondylitis (Tennis elbow)
  • Carpal Tunnel Syndrome
  • DeQuervain’s Syndrome
  • Thoracic Outlet Syndrome
  • Tension Neck Syndrome
  • Bursitis
  • Trigger Finger


Tendonitis & Tenosynovitis

Kenny & Wright (2011)


Tendonitis and tenosynovitis are tendon injuries, which often occur together. Most commonly, they are caused by overuse of a tendon.

A tendon is a tissue that attaches muscle to bone, some of which are covered by a synovial sheath. This sheath creates a fluid, which allows that tendon to move smoothly when it pulls a bone it is connected to.

While they often occur together, the injury types differ:

          Tendonitis: Inflammation of the tendon

Tenosynovitis: Inflammation of the sheath that surrounds a tendon, it often occurs around the wrist


These injuries usually occur from overuse of the tendons such as repetition at work. They are most likely to occur in middle-aged adults and in those whose work involves repetition such as writing, typing or mousing.


  • Tendonitis usually occurs at the part of the tendon that attaches to the bone.
  • Pain, especially when moving the affected area
  • Tenderness
  • Swelling of the affected part of the tendon
  • Overlying skin may feel warm
  • Reduced movement
  • Weakness
  • Stiffness
  • Symptoms may last only a few days or for weeks or months if not addressed and treated properly.
  • May impact any tendon of your body (Tendons around your wrist and hand are the most commonly affected)


Occupational Risk Factors

  • Prolonged load on shoulders
  • Repetitive wrist motions
  • Repetitive shoulder motions
  • Sustained hyperextension of arm


Functional Implications

  • Decreased tolerance for prolonged lifting, and repetitive motions
  • Repetitive movements may need to be avoided
  • A change of duties may decrease symptoms

 Epicondylitis (Tennis elbow)

Flatt (2008)

Mallen, Chesterton, & Hay (2010)


The anatomical cause of epicondylitis is sudden and repetitive use of the forearm extensor muscles.
The muscle involved anatomically is the Extensor Carpi Radialis Brevis (ECRB), which arises from the lateral epicondyle of the humerus and passes distally inserting into the base of the 3rd or central metacarpal in the hand. The ECRB is the prevailing midline extensor of the hand.

  • Impacts men and women equally
  • Most common in people age 35-55



  • Pain is often mild
  • Usually occurs in the dominant arm
  • Pain often presents as a small area of chronic pain on the elbow laterally
  • Pain can be episodic and usually lasts 6-months to 2-years, often resolving within 12-months. An acute flare may last 6‐12 weeks.
  • Pain occurs during wrist extension
  • Pain present when shaking hands with someone
  • Frequently the person experiences a weakened grip
  • No one incident produces the pain symptoms, repetitive use of the hand will create, maintain, or increase a person’s level of discomfort or pain.
  • A sudden onset of symptoms is uncommon


Occupational Risk Factors

  • Repetitive wrist movements, especially those associated with resistance
  • Repetitive turning or lifting at the wrist (i.e- keyboard use)


Functional Implications

Aggravating factors should be avoided which include:

  • Muscle overload
  • Strong repetitive motion with the elbow extended
  • Actions such as playing a musical instrument, painting, raking, using screwdrivers, pliers, and hammers, cutting meat, turning door- knobs;
  • Twisting movements
  • Lifting objects with an extended wrist

Workers may experience a decreased tolerance for:

  • Twisting movements
  • Lifting objects with the effected arm
  • Repetitive motions with effected arm
  • An increased need for frequent rests of the impacted arm

Carpal Tunnel Syndrome

Bickel (2010)

Scanlon & Maffei (2009)



The carpal tunnel is located in the wrist between the carpal bones. Running through this tunnel are the tendons responsible for flexing the hand, as well as the median nerve, which has both motor and sensory functions. This nerve is necessary for tasks such as gripping objects.

When the wrist is flexed or extended, the mass within the carpal tunnel is increased putting greater pressure on the median nerve. This compression is what may cause carpal tunnel syndrome (CTS) symptoms.

CTS occurs in approximately 3.8% of the general population with women being 3-4 times more likely to develop this condition. In half of all cases, the wrists are affected bilaterally.



  • Sensory Changes
    • Commonly occur at night and can become continuous
    • Tingling, numbness, or pain sensations from the elbow to hand
  • Weakness
    • A later symptom when a person has moderate to severe CTS
    • An inability to difficulty to grip objects


Occupational Risk Factors

Pressure on the carpal tunnel can be caused by:

  • Repetitive movements including rotation, flexion, or extension.
    • These movements are common in automotive, secretarial, or computer work.
  • Trauma to the wrist or hand
    • May result in facture or swelling
  • Metabolic, inflammation, or infections
    • These may alter the structures in the wrist, an example of this is pregnancy
  • Medications
    • Ones which increase edema (i.e- some hormone replacement therapies)
  • Congenital Malformations
    • A person may have an abnormally small carpal tunnel
  • Idiopathic causes


Functional Implications

  • Decreased tolerance for gripping actions
  • Increased pain with actions which include wrist flexion, extension, or rotation
  • Decreased tolerance for repetative wrist motions

DeQuervain’s Syndrome

Bahm, Szabo & Foucher (1995)

Forget, Piotte, Bourbonnais, Arsenault, & Harris (2006)



DeQuervain’s disease is caused by a stenosis of the first dorsal compartment of the wrist, which contains extensor pollicis brevis and abductor pollicis longus tendons, resulting in thickening of the overlying retinaculum. These tendons are important when completing actions that include the extension, or straightening of the thumb.



The symptom that people find impacts their function the most is pain, specifically over the radial (thumb) side of the wrist or at the base of the thumb. Typically, symptoms are minimized by rest, and aggravated by activity.

Other symptoms that may occur include:

  • A decline in thumb functioning
  • Stiffness
  • Impacted range of motion
  • Decline in strength


Occupational Risk Factors

  • Repetitive movements including twisting and forceful gripping of the hand


Functional Implications

  • Studies have found that DeQuervain’s syndrome may result in decreased thumb strength and range of motion in all directions.
  • Decreased tolerance for movements involving the thumb, especially gripping and twisting motions


Thoracic Outlet Syndrome

Cowles (2012)

Huang & Zagar (2004)



The thoracic outlet is the area of the body between the collarbone and rib cage. Nerves and blood vessels travel from the spine and larger vessels on the body through the thoracic outlet towards the arms. When there is not enough room for these structures to pass between the collarbone and ribs, compression occurs causing thoracic outlet syndrome symptoms to appear.

There are multiple reasons that the thoracic outlet may not be large enough for the structures to pass through, which include:

  • The individual may have an extra rib located above the first one
  • The individual may have a tighter band than usual connecting their spine to their ribs.



It is common the individuals with this syndrome have previously injured or overused their shoulder. Thoracic Outlet Syndrome (TOS) is more commonly found in woman, and its onset generally occurs between the ages of 20-50.

Symptoms that a person may present with include:

  • Pain or tingling in the neck and shoulder
  • Tingling, pain, and numbness in the fingers, specifically in the pinky and ring fingers
  • Tingling, pain, and numbness of the inner forearm
  • Weakened grip due to a decrease in the strength of hand muscles
  • Decreased circulation of the hand or forearm
    • This will show in an individual by turning the skin a bluish colour, swelling of the arms, or having cold hands


Occupational Risk Factors

  • Carrying heavy loads may aggravate symptoms, especially pain in the neck and shoulders.
  • An individual that has poor posture resulting in droopy shoulders are at a higher risk of developing thoracic outlet syndrome due to the increased pressure that is put on the structures in the thoracic outlet when this position is assumed.
  • Carrying items on the shoulder
  • Lengthy bouts of shoulder flexion
  • Extension of the arms above shoulder height


Functional Implications

  • Decreased tolerance for carrying heavy loads, and of overhead activities
  • Decreased strength and range of motion of the shoulder

 Tension Neck Syndrome

Franca, Senna-Fernandes, Cortez, Jackson, Bernardo-Filho & Guimaraes (2008)

Mayo Clinic Staff (2012)

Mekhora, Liston, Nanthavanij, & Cole (2000)



Tension neck syndrome (TNS) is when myofascial pain occurs in the shoulders and neck. Myofascial pain is chronic, and is characterized by sensitive or trigger points in the muscle, which causes pain in other areas of the body. This pain can appear to be unrelated to the trigger location, and is also known as referred pain.



Symptoms and diagnosis of TNS is more commonly found in woman. The symptoms that an individual with TNS may present with include:

  • Muscle fatigue in the neck and shoulders
  • Muscle stiffness in the neck and shoulders
  • Neck and shoulder pain or tenderness
  • Headaches, which may radiate from the neck
  • Tender or trigger points may be locatable in the neck and shoulder
  • Chronic pain lasting longer than 3 months


Occupational Risk Factors

  • Extended or prolonged computer use (i.e office workers, students, etc.)
  • Prolonged restricted posture
  • Repetitive contraction or motion of muscles
  • Stress-induced muscle tension
  • Lack of rest breaks or opportunities to stretch


Functional Implications

  • Decreased tolerance for repetitive motions
  • Decreased movement and range of motion due to pain
  • Reduction in length and pace of work
  • Rotation of job duties may be required



Bursitis (2013)



Bursitis is a condition in which a bursa in the body becomes inflamed. A Bursa is a membrane located in many joints in the body. They act as a cushion in the joint, decreasing friction between bones and increasing joint flexibility.

Individuals are at an increased risk of bursitis if they are diabetic, overweight, or elderly.



  • Pain surrounding the joint
  • Pain when pressure is applied to the joint
  • Pain with use of the joint
  • Warmth, redness, and swelling of the joint
  • Pain with active range of motion of the joint
  • Symptoms are most common in the elbow, hip, shoulder, and knee
  • Symptoms may last for a few days, or up to a few years


Occupational Risk Factors

  • Overuse of the joint
  • Repetitive use of a joint


Functional Implications

  • Decreased active range of motion
  • If overuse causes are not changed, symptoms will likely continue or worsen
  • Decreased tolerance of repetitive movements of the joint
  • Increased need of protective joint equipment (i.e. knee pads, etc.) if positions or repetitive motion cannot be changed
  • Increased need for rest of the joint


 Trigger Finger

Asif (2010)

Bafus & Froimson (2012)

Guerini, Pessis, Theumann, Le Quintrec, Campagna, Chevrot, Feydy, Drapé (2008)



Trigger finger is a condition that prevents an individual from straightening fully, or creates a jerking motion when moving the finger from a flexed to extended position. This condition usually includes the metacarpophalangeal (MCP) joint, more commonly known as the knuckles.

In an individual with trigger finger, their flexor tendon does not have the ability to glide smoothly along its sheath. The sheath acts like a tunnel, which the tendon usually passes through without issue. When a person has trigger finger, the sheath is either swollen, or there is a mismatch between the size of the tendon and room available in the sheath. This swelling occurs at the MCP joint, which can form nodules on the flexor tendon. These nodules take away the ability of the flexor tendon to glide smoothly. When the hand is flexed, the nodules will get stuck on the MCP joint, locking the finger in a flexed position.

The finger that is most often impacted by this condition is the ring finger.



  • Redness, pain, and swelling of the knuckle (MCP joint)
  • Finger locks occasionally
  • Finger is locked in a flexed position


Occupational Risk Factors

  • Common in occupations such as musicians and manual labourers
  • Repetition or repetitive use of the hand


Functional Implications

  • Restriction of gripping and pinching
  • Avoidance of activities that put pressure over the knuckle
  • Increased need for rest, for a few days to 6 weeks depending on the severity





Asif, K. (2010). It’s Questionable: The Doctor Is In – Trigger Finger. Modern Drummer: International Index to Music Periodicals, 34(2), 16.

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Bahm, J., Szabo, Z., & Foucher, G. (1995). The anatomy of de Quervain’s disease: A study of operative findings. International Orthopaedics, 19, 209-211.

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Flatt, A.E (2008). Tennis Elbow. Baylor University Medical Center Proceedings, 21(4), 400-402.

Forget, N., Piotte, F., Bourbonnais, D., Arsenault, J., & Harris, P. (2006). Thumb Strength and Mobility in DeQuervain’s Disease. Journal of Hand Therapy, 441-442.

Franca, D.L.M., Senna-Fernandes, V., Cortez, C.M., Jackson, M.N., Bernardo-Filho, M., & Guimaraes, M.A.M. (2008). Tension neck syndrome treated by acupuncture combined with physiotherapy: A comparative clinical trial. Complementary Therapies in Medicine, 16, 268—277.

Guerini, H., Pessis, E., Theumann, N., Le Quintrec, J., Campagna, R., Chevrot, A., Feydy, A., Drapé, J. (2008). Sonographic Appearance of Trigger Fingers. Journal of Ultrasound Medicine, 27, 1407–1413.

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Mayo Clinic Staff. (2012). Myofascial pain syndrome. Retrieved from

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