Musculoskeletal Disorders (MSD)

Collage of images showing people doing work that is known to cause MSD/RSI

When a muscle, tendon, nerve, or joint is stressed and traumatized on a repeated basis for days, months or years,
those body tissues eventually become damaged.

This leads to a work-related musculoskeletal disorder (MSD).

Work-related musculoskeletal disorders, sometimes referred to as repetitive strain injuries (RSI),
are caused by increased trauma to an area and and overuse to injuries.

When a MSD develops a worker experiences:

Icon of a swollen, puffy foot depicting the concept of "swelling"

(as tissues become more and more irritated)

Icon of knee joint with pain points and inflammation on the inside depicting the concept of "pain and discomfort"

Pain and Discomfort

An icon of person holding their neck / shoulder area and bending their head to one side, depicting the concept of "stiffness and range-of-motion" loss

Stiffness and Range-of-Motion Loss

Icon of a person lifting a box and another person tending to a child, depicting the concept of both home and work duties

Inability to Perform Functions and Duties
(both at work and at home)

Hazards that cause musculoskeletal disorders include:

Icon of a person bending over using a drill, depicting an "awkward posture"

Awkward Postures

Icon of a person sitting at a computer workstation depicting a "static posture"

Static Postures

Icon of a person pushing hard against an object, depicting the concept of "force"


Icon of a machine cog circled by three arrows, depicting the concept of "repetitive movements"

Repetitive Movements

Icon of an object in the centre with wavy lines on both sides, depicting the concept of "vibration"





It is common for pain in the arm and hand to stem from problems in the neck.

Neck and arm strain can be prevented by keeping the head and neck in proper alignment. The slight inward curve of the neck balances the head on the spine. Holding the head forward disturbs this balance, straining the joints and the muscles of the neck and upper back. This posture also causes compression of the nerves and blood vessels as they exit the neck, leading to symptoms in the arm and hand.

Neck problems generally arise from prolonged static neck flexion and shoulder abduction or flexion, lack of upper-extremity support, and inadequate work breaks.

Myofascial Pain Disorder (MPD)

MPD is characterized by pain and tenderness in the neck, shoulder, arm muscles, and a restricted range of motion. Possible causes include overloaded neck/shoulder muscles.

Cervical Spondylosis

This disorder is characterized by intermittent/chronic neck and shoulder pain or stiffness, headaches, hand and arm pain, numbness, tingling, and clumsiness. Possible causes include age-related spinal disc degeneration leading to nerve compression and spinal cord damage, arthritis, and time spent with the neck in sustained awkward postures.


Most individuals with low back pain do not simply injure their back in one incident but rather gradually over time.
Repeated stresses from over the years begin to add up and slowly cause degeneration of various parts of the spine, resulting in low back pain.

Disc Problems

In a seated posture the pressure in the lumbar discs increases by 50% as compared to standing. Additionally, sitting in an unsupported posture can cause twice the amount of stress as compared to standing. During bending (forward flexion) and twisting (rotation) motions of the spine, the pressure on the lumbar discs increases by 200%. This type of pressure on the disc can lead to a bulge or herniation, causingcompression on a spinal nerve.


Sciatica is characterized by pain in the lower back or hip radiating to the buttocks and legs, causing leg weakness, numbness, or tingling. It is commonly caused by bulging, prolapsed or herniated discs compressing a spinal nerve root and isworsened with prolonged sitting or excessive bending and lifting.


Hand-Arm Vibration Syndrome

Hand-Arm Vibration Syndrome (HAVS)is a disease that involves circulatory disturbances, sensory and motor disturbances and musculoskeletal disturbances. It is caused by the transfer of vibration from a tool or workplace to a worker’s hands or arms. The level of hand-arm vibration is determined by measuring the acceleration of the tool or object grasped by the worker.


The wrist is in constant demand, often sustaining excessive and repeated stresses and strains. The safest position for the wrist is a straight or neutral position. Special care should be used to avoid bending the wrist downwards (flexion) or outwards (ulnar deviation).

Carpal Tunnel Syndrome (CTS)

CTS is one of the most common problems that affect the hand and wrist. CTS occurs when the median nerve, which runs from the forearm into the hand, becomes pressed or squeezed at the wrist. The median nerve controls sensations to the palm side of the thumb and fingers (although not the little finger), as well as impulses to some small muscles in the hand that allow the fingers and thumb to move.

Tendonitis of the Wrist

Tendonitis is an inflammation of tendons, which are the structures that attach muscle to bone. Tendonitis of the wrist is accompanied by pain, swelling and inflammation on the thumb side of the wrist, and is made worse with grasping and twisting activities (e.g. polishing and scaling). People with this disorder have often noted an occasional “catching” or snapping when moving their thumb.

Guyon’s Syndrome

Guyon's canal is a space at the wrist between the pisiform bone and the hamate bone through which the ulnar artery and the ulnar nerve travel into the hand. Compression of ulnar nerve occurs in this space at the base of the palm. It is commonly caused by repetitive wrist flexing or excessive pressure on palm/base of hand. It is characterized by pain, weakness, numbness, tingling, burning in the little finger and part of the ring finger.


Grasping or pinching light objects becomes a problem when the item is held for long periods. The pressure can reduce blood flow and strain tendons, leading to hand symptoms. Repetitive motion, such as prolonged grasping, can lead to tendonitis (inflammation of the tendons).

DeQuervain’s Tenosynovitis

This disorder is characterized by pain and swelling in the thumb and wrist area when grasping, pinching, twisting, and a decreased range of motion of thumb with pain. Possible causes include synovial sheath swelling, thickening of tendons at base of thumb, and repeated trauma or twisting hand/wrist motions.

Trigger Finger

Trigger Finger often results from sustained forceful grips and repetitive motion which irritates the tendon and tendon sheath (tenosynovium). Nodules form in tendon causing warmth, swelling, and tenderness of the tendon. Pain occurs during movement that place tendons in tension. The fingers lock in the “Trigger Position”.


The elbow should generally be held at a right angle or ninety degrees. Because blood vessels and nerves supplying the forearm and hand travel along the elbow joint, repeated or prolonged bending can cause compression, leading to forearm and hand symptoms.


Injuries at the elbow typically occur at either the inside of the elbow, referred to as Medial Epicondylitis (golfer’s elbow), or outside of the elbow, known as Lateral Epicondylitis (tennis elbow). The forearm flexors, used to make a fist, attach at the inside portion of the elbow. Whereas the forearm extensors, used to open the hand, attach at the outside of the elbow.

Cubital Tunnel Syndrome

Cubital Tunnel Syndrome is often caused by prolonged use of the elbow while flexed, resting the elbow on an armrest, or trauma from overuse can compress the ulnar nerve. It is characterized by pain, numbness, tingling and impaired sensation in the little and ring fingers, side and back of hand, loss of fine control, and reduced grip strength.


Rounding the shoulders can compress nerves, arteries, and veins that supply the arm and hand, leading to upper extremity symptoms. Poor thoracic alignment also limits oxygen intake. Slouching forward compresses the chest cavity, preventing the diaphragm muscle from completely filling the lungs with air. When oxygen is diminished, the body experiences fatigue and loss of concentration.


The term bursitis means that the part of the shoulder called the bursa is inflamed. There are many different problems that can lead to symptoms from inflammation of the bursa, one of those being impingement.

Thoracic Outlet Syndrome (TOS)

TOS is a condition resulting from compression of the nerves, arteries, and veins as they pass through from the neck to the arm (thoracic outlet). Possible causes include tight scalenes and pectoralis muscles, extra cervical rib, and prolonged durations of working with elevated elbows. This disorder is characterized by pain in the neck, shoulder, arm or hand, numbness and tingling of fingers, muscle weakness/fatigue, and cold sensation in the arm, hand or fingers.

Rotator Cuff Tear

The rotator cuff (RC) is a group of 4 muscles; supraspinatus, infraspinatus, teres minor and subscapularis. The RC assists with both gross and fine motor control of the arm. RC injury tends to occur where the muscle’s tendon attaches to the bone.

Rotator Cuff Tendonitis

This disorder is characterized with pain and stiffness in the shoulder associated with backward and upward arm movements, and weakness of rotator cuff muscles. Possible causes include swelling or tearing of rotator cuff soft tissue, shoulder joint bone spurs/abnormalities, and poor shoulder posture.


Besides the most common upper extremity disorders (above), MSD may also affect the knees, ankles and feet depending on the type of work that you do.

Plantar Fasciitis

The main symptom of Plantar Fasciitis is pain in the center of the heel with weight bearing.  This is usually worse in the morning when the foot is first placed on the floor. The pain associated with Plantar Fasciitis is gradual in onset and is usually located over the inner aspect of the heel.  Pain may also occur in the arch area of the foot.  Occasionally, the pain will be sudden in onset, occurring after missing a step or after jumping from a height.  This condition causes what is known as “first-step pain.”  The degree of discomfort can sometimes lessen with activity during the course of the day or after “warming-up”, but can become worse with prolonged or vigorous activity.  The pain may also be more severe in bare feet, in shoes with little or no padding at the sole, and slippers.



MSD Prevention Guideline for Ontario

Developed by the Centre of Research Expertise for the Prevention of Musculoskeletal Disorders (CRE-MSD)

Providing Workplace Solutions to Prevent Musculoskeletal Disorders (MSD), because...

Work shouldn't hurt logo

A collage of images that represents the key steps from the website

MSD Quick Start Guide

A simple and useful guide for busy people in small businesses

Roadmap to Success

Overview of the Ontario MSD Prevention Guideline for larger organizations.

Animations & Videos

Introducing MSD, website feature highlights, demonstrations and more...

MSD Resource Filters

Search for Prevention Resources based on your needs.

Centralized MSD Risk Assessment Resources

Not sure what method to use? The Tool Picker will help you find a method best suited to your work.

Employer? Workers? JHSC member?

The stakeholder tab gives quick access to information of use to you!

Developing Procedures for Musculoskeletal Disorders (MSD) Prevention

Having a comprehensive Musculoskeletal Disorders (MSD) Prevention Program will assist with reducing or eliminating the hazards that lead to musculoskeletal injury.  This presentation will discuss the important elements that should be included in a program including assigning responsibility, workstation design, manual material handling procedures, procurement of tools and equipment, the training required and evaluation.


Prevent Musculoskeletal Disorders (MSD) at Work

Sample screen shots from the PainPoint app

Download our app that provides a basic ergonomic assessment by running through a series of diagrams and questions to:

•  pinpoint musculoskeletal pain  •  identify possible sources
•  discover practical solutions...

...right from your smartphone!
(the App Store version is not currently available)


Icon of an exclamation mark inside a triangle representing the concept of a hazard

Musculoskeletal Disorder

Icon of a shield with a cog on the front surrounded by a dotted line leading up to a couple of hazard warning triangles

Musculoskeletal Disorder

These other areas of our website may also be of interest to you: