Musculoskeletal Disorders
Musculoskeletal Disorders (MSDs)
Musculoskeletal Disorders (MSDs) are injuries or disorders of the muscles, tendons, joints, nerves, ligaments, and vertebral discs. When these tissues are stressed on a regular basis without adequate time for recovery, they can eventually become damaged and lead to the development of MSDs.
Signs
- can be physically observed, felt or heard
- Redness, swelling, reduced range of motion, loss of strength, etc.
Symptoms
- cannot be seen but can be felt by the individual
- Pain, discomfort, aching, numbness, tingling, burning sensation, stiffness, fatigue, etc.
Mild
Beginning of physical discomfort such as light pain.
Symptoms: Pain, aching, fatigue
Onset: Weeks or Months
Job Performance: Not affected
Visible Signs: None
Treatment: May be reversible if treated early
.
Moderate
Increased physical discomfort such as more frequent and intense pain.
Symptoms: Pain, aching, fatigue, sleep difficulty
Onset: Months
Job Performance: Decreased
Visible Signs: May be present
Treatment: Difficult and slower recovery
Severe
Persistent physical discomfort such as intense and prolonged pain.
Symptoms: Constant to intense pain, fatigue, sleep difficulty
Onset: Months to years
Job Performance: Unable to perform job duties
Visible Signs: Often present
Treatment: Greater risk of permanent damage
Specific Musculoskeletal Disorders (MSDs)
Signs and Symptoms
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:
- Swelling (as tissues become more and more irritated)
- Pain and Discomfort
- Stiffness and Range-of-Motion Loss
- Inability to Perform Functions and Duties (both at work and at home)
Hazards that cause musculoskeletal disorders include:
- Awkward Postures
- Static Postures
- Force
- Repetitive Movements
- Vibration
Body Map
Shoulder
Elbow
Epicondylitis
Knee
Ergonomic Risk Factors
Awkward Postures
- Postures that deviate from neutral (e.g. reaching, twisting, bending, etc.)
- kneeling
- working with arms above shoulder level
Static Postures
- Any posture that is held for an extended time
Force
- Forceful exertions (i.e. lifting,
carrying, gripping, etc.) - Contact stress
- Mechanical stress
Inadequate Recovery Time
- Similar muscle actions performed multiple times in a short period
- Sustained muscle contractions without enough rest
- May lead to fatigue, weakness or altered movement patterns
Vibration
- Mechanical oscillations of any frequency that are transferred to the body – may affect the entire body or individual body segments
Temperature
- Working in hot or cold conditions
Contact Stress
- External pressure that is applied to a part of the body for a sustained period
Psychosocial
- The combination and effect of nonphysical aspects (social, cultural, and environmental influences) on the mind and behavior
Combination Effect
- Many or all of the risk factors act in synergy
Repetition
- Short cycle time or fast paced work
- Inadequate recovery time
- Sustained or static postures(i.e. standing)