Occupational Injuries and Illnesses that lead to California Workers’ Compensation Claims


In the workers' compensation system, an occupational injury or illness is considered "work-related" if an event or exposure at work either

(a) caused the condition, or
(b) aggravated a pre-existing condition.1

Any illness or injury can be a work injury. The most common occupational injury is to the cervical, thoracic or lumbar spine in the back.

Common upper extremity injuries include those to the:

The most common lower extremity injury is to the knee.

Other common occupational illness and injuries include:

  • heart
  • hernia
  • gastro- intestinal
  • psychiatric

Injured parts of body are rated by the percentage of loss of function, and this is referred to as an injured worker's level of impairment. As each part of the body is different, each rating method is different.

All injuries in California are rated using the American Medical Association Guides to the Evaluation of Impairment, 5th Edition to determine permanent disability.

For upper and lower extremities, range of motion is a common measurement of impairment. For illnesses, the measure is based on factors such as

  • blood pressure,
  • successful treatment, and
  • continued symptoms.

In this article, our California personal injury attorneys will explain:

california workers' comp work related injuryh
Any type of injury or illness can be an occupational, or work, injury. The employee only has to show that the employment is the main cause of the injury.

1. Occupational injuries and illnesses

Any type of injury or illness can be an occupational, or work, injury. The employee only has to show that the employment is the main cause of the injury.2

However, certain types of injuries and parts of body are more likely to be injured at work.

The top five injuries as a percentage of total workers' compensation claims are:

  • strains and sprains (30 percent)
  • cuts or punctures (19 percent)
  • contusions (12 percent)
  • inflammation (5 percent)
  • fractures (5 percent)3

Sixty-six percent of all injuries in California workers' compensation are for:

  • back,
  • shoulder,
  • knee,
  • loss of grasping power, or
  • psychiatric4

An injured worker that files a claim for a work injury in California should list all body parts that he or she believes are injured.

An occupational injury can be a specific injury, a specific incident, or a cumulative trauma, an injury over time. Any injury may require temporary disability or may allow the injured worker to continue working on modified duty or light work.

Treatment for all injuries must go through Utilization Review to see if the treatment is appropriate. Any occupational injury can be treated outside of California.

With any injury, the attorney for the insurance company make conduct a deposition to see if there have been any prior injuries with the same part of the injured worker's body. The insurance company will want to know if any prior conditions caused some or all of the disability, called apportionment to pre-existing conditions.

Also, note that in some cases a worker may not become aware of an insidious injury until after leaving a job. For advice on dealing with this situation, see our page on filing a workers compensation claim after job terminationfiling a workers compensation claim after job termination. 

2. Back Injuries

The spine consists of vertebrae, or column of bones, that are stacked on top of one another and divided into three regions:

  • cervical (7 vertebrae) located in the upper back and neck
  • thoracic (12 vertebrae) in the middle of the back
  • lumbar (5 vertebrae) in the lower back and tailbone

Between each vertebrae are disks, which act like shock absorbers between the vertebrae.5

2.1. Injuries to the cervical, thoracic or lumbar spine

Back injuries include:

  • sprains and strains
  • herniated disks
  • fractured vertebrae6

2.2. Evaluation of the back for permanent disability

The back in California workers' compensation is rated in Chapter 15 of the AMA Guides.

An injured worker can have a back injury in any or all spinal regions - cervical, thoracic, or lumbar.

The three regions of the spine are evaluated in one of two ways:

  • muscle spasms and pain in the spine itself, or pain from the spine going to the to the arms or legs
  • range of motion

The method of evaluation depends on the type of injury.

Example: Gary injures his low back at work lifting boxes. Gary has pain in his low (lumbar) and middle (thoracic) back. He also has pain and numbness going down his right leg to the back of his knee.

An MRI of his lumbar spine shows he has a bulging disc.

Gary is given disability for both his lumbar spine due to the pain down his right leg and for his thoracic spine due to pain and muscle spasms in the middle of his back.

california workers' comp shoulder injury attorneys
Shoulder pain during work

3. Shoulder Injuries

The shoulder consists of three bones. Two of the bones are like a ball and socket and allow the shoulder to move. Other parts of the shoulder, such as the rotator cuff, stabilize the shoulder socket. 7

3.1. Injuries to the shoulder joint

Common problems include:

  • sprains and strains
  • dislocations
  • separations
  • tendinitis
  • bursitis
  • torn rotator cuffs
  • frozen shoulder
  • fractures
  • arthritis8

3.2. Evaluation of the shoulder

The shoulder is evaluated in the AMA Guides Chapter 16 - Upper Extremities.

A doctor will determine the range of motion of an injured worker's shoulder and rate the disability. The rating will depend on the ability of the injured worker to raise the shoulder above his or her head, to the side, and behind. There are six total range of motion measurements taken.

Example: Janet injures her shoulder from repeatedly doing assembly work.

Her doctor has Janet try to move her shoulder in different directions as far as she can. Janet is not able to move her shoulder above her head or the side as well as she could before the injury. The doctor records these measurements.

Based on these measurements, Janet is given 8% impairment for her shoulder.

4. Knee Injuries

The knee consists of three bones – the upper leg bone (femur), lower leg bone (tibia), and kneecap (patella).

The ends of the bones are covered with a layer of cartilage, a slick, elastic material that absorbs shock and allows the bones to glide easily against one another as the knee moves.9

4.1. Injuries to the knee

  • arthritis
  • anterior cruciate ligament (ACL) tear10

Serious knee injuries may require a knee replacement.

4.2. Evaluation of the knee

The knee in California workers' compensation is evaluated using the AMA Guides Chapter 17 - Lower Extremities.

There are several ways to evaluate the knee for disability, including:

  • range of motion
  • arthritis
  • type of surgery
  • walking ability

Example: Samantha is walking from one office building to another to attend a meeting. She steps wrong an injures her knee. An MRI shows that she has torn her ACL. This results in pain and a decrease in her range of motion.

Samantha has surgery and recovers from the procedure.

After surgery, the range of motion in Samantha's knee returns to normal, and she has little pain. But because she has surgery, she is given a 3% rating for her knee.

5. Hands / Wrist Injuries

The hand and wrist are made up of many different bones, muscles, and ligaments that enable a wide range of movements. The wrist is formed where two bones in the forearm, the radius and ulna, meet. There are joints where bones meet at the wrist and in the fingers.

Ligaments connect the bones and tendons to the muscles. 11

5.1. Injuries to the hand and wrist

Hand problems include:

  • carpal tunnel syndrome - compression of a nerve as it goes through the wrist, often making fingers feel numb
  • injuries that result in fractures, ruptured ligaments, and dislocations
  • osteoarthritis - wear-and-tear arthritis, which can also cause deformity
  • tendinitis - irritation of the tendons

5.2. Evaluation of the hand and wrist

The hands and wrist are evaluated in the AMA Guides Chapter 16 - Upper Extremities.

There are four range of motion measurements taken for the wrist – back and forth, and up and down.

Each finger of the hand is measured at each joint. The three joints in each finger are also evaluated based on how well they bend.

Example: Julio's right hand is crushed by a concrete block.

The doctor evaluating Julio measures the range of motion of his right wrist and the fingers and thumb of his right hand. Julio has difficulty bending his wrist down and bending three of his fingers.

He is given 19% disability for the limited range of motion in his wrist and fingers.

california workers' comp elbow injury
The elbow in California workers' compensation is evaluated in the AMA Guides Chapter 16 - Upper Extremities.

6. Elbow Injuries

The elbow is where the two bones in the forearm, the radius and ulna, meet the bone in the upper arm, the humerus. There are ligaments that hold the bones of the elbow together and tendons that hold the muscles to the elbow.12

6.1. Injuries to the elbow joint

Elbow injuries include:

  • tendinitis
  • sprains and strains
  • fractures
  • bursitis
  • arthritis13

A common elbow complaint is cubital tunnel, condition where there is pressure on the ulnar nerve, causing pain and numbness.14

6.2. Evaluation of the elbow joint

The elbow in California workers' compensation is evaluated in the AMA Guides Chapter 16 - Upper Extremities.

There are four ranges of motion for the elbow – up and down, and back and forth.

Example: Joe operates a metal stamping machine. He injures his right elbow from repeatedly working with the machine. He has pain in his elbow and down his elbow into his ring and little finger.

In the range of motion testing, Joe cannot straighten his elbow and or move it toward his body.

Joe is given a 13% rating for his elbow.

7. Heart Injuries

The heart is a muscle that pumps blood throughout the body. It has four chambers and four valves to prevent backflow of fluid. An electrical system causes contractions to pump blood.15

7.1. Injuries to the heart

Heart injuries include:

  • coronary heart disease
  • arrhythmias
  • high blood pressure
  • enlargement of the heart16

Heart injuries can be considered work injuries if they're caused or aggravated by stress on the job.

7.2. Evaluation of the heart

The heart is evaluated using the AMA Guides – Chapters 3 & 4.

The evaluation depends on the type of condition.

Example: David is a police officer. He has a significant amount of stress on the job. A specialist in internal medicine evaluates David and reviews his medical records.

In the medical records of David's treatment visits, his blood pressure is greater than 140 over 90 on three occasions.

David has stage 1 hypertension and is given a rating of 5%.

8. Hernia Injuries

A hernia happens when part of an internal organ or tissue bulges through a weak area of muscle.17

8.1. Hernia Injuries

There are several types of hernias, including:

  • inguinal - in the groin. This is the most common type.
  • Umbilical - around the belly button
  • Incisional - through a scar
  • Hiatal - a small opening in the diaphragm that allows the upper part of the stomach to move up into the chest.18

8.2. Evaluation of hernias

Hernias in California workers' compensation are evaluated using the AMA Guides Chapter 6 – the digestive system.

A hernia can be evaluated based on discomfort, an inability to lift, or whether there is any visible indication of the hernia. A visible bulging through the skin may occur when a hernia is not repaired, or when a previous repair is unsuccessful.

Example: Kent develops a hernia in his groin by trying to lift a heavy box at work. He has surgery to repair the hernia. There is a wire mesh inserted to repair his abdominal wall.

Kent has no restrictions on what he can lift and no visible hernia except for a scar. But he does have some discomfort. He is given a 2% rating.

9. Gastro-intestinal Injuries

The esophagus is the tube that carries food from the mouth to the stomach. Gastroesophageal reflux disease (GERD) happens when a muscle at the end of the esophagus does not close properly. This allows stomach contents to leak back into the esophagus and irritate it.19

9.1. Injuries to the gastro-intestinal (GI) system

Taking non-steroidal anti-inflammatory drugs (NSAIDs) is a significant risk factor for GERD.20 GI injuries can be considered work injuries if they're caused or aggravated by stress on the job.

9.2. Evaluation of the gastro-intestinal system

GI complaints are evaluated using chapter 6 of the AMA Guides.

Factors in evaluating GERD include:

  • continued symptoms
  • need for treatment
  • dietary restrictions
  • weight loss

Example: Gil takes NSAIDs for pain. The medication upsets his stomach. He stops taking the medication but continues to have symptoms including pain and acid reflux.

Gil is able to maintain his weight and does not have any dietary restrictions. He is given a 4% rating.

10. Psychiatric Injuries

A psychiatric injury in California workers' compensation is a mental disorder caused or aggravated by work that results in permanent or temporary disability or need for medical treatment.21

Psychiatric injuries affect relationships, work, and ability to take care of oneself.

See psychiatric trauma for a complete discussion of this topic.

10.1. Psychiatric conditions

A psychiatric work injury is diagnosed using the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Third Edition – Revised.

Note that starting in 2020 through 2024, certain firefighters and peace officers may be able to recover workers' comp for PTSD (post traumatic stress disorder).22

10.2. Evaluation of the psychiatric injury

Psychiatric conditions are rated using the Global Assessment of Function (GAF) scale in the Permanent Disability Rating Schedule. This rates an injured worker on a scale from one to one hundred on his or her level of functioning.

An injured worker is evaluated by a psychiatrist or psychologist, who consider psychological, social, and occupational functioning of the injured worker.23

Example: Amber works in a call center and suffers a psychiatric injury from doing the work of two people.

She is evaluated by a psychiatrist. She tells the doctor that she is depressed and has difficulty sleeping.

The doctor gives her a GAF score of 67. This amounts to 5% disability.

11. Any injury may be a work injury

Although injuries to certain parts of the body may be more common, any injury can be a work injury.

Any worker that suspects a work injury should report it, file a claim for workers' compensation benefits, and see a doctor.

Call us for help...

california workers' compensation attorneys
Call us at (855) LAW-FIRM

For help with filing a workers compensation claim in California, completing workers comp forms or appealing a denial of benefits, contact us at (855) LAW-FIRM. Our firm helps police officers, firefighters and other workers to get compensation for their job-related injuries in California. (For Nevada cases, please see our article on occupational illnesses and diseases in Nevada workers compensation cases.)

Legal References:

  1. https://www.bls.gov/iif/oshdef.htm

  2. Alice Azevedo v. WCAB (1966) 31 Cal. Comp. Cases 223.

  3. https://www.insurancejournal.com/news/national/2016/05/18/409006.htm

  4. Robert Reville et al. Rand study An Evaluation of California's Permanent Disability Rating System (2005)

  5. https://www.arthritis.org/about-arthritis/where-it-hurts/back-pain/back-spine-anatomy.php (there is also the sacrum and coccyx that are fused vertebrae)

  6. https://medlineplus.gov/backinjuries.html

  7. https://www.arthritis.org/about-arthritis/where-it-hurts/shoulder-pain/shoulder-anatomy.php

  8. https://medlineplus.gov/shoulderinjuriesanddisorders.html

  9. https://www.arthritis.org/about-arthritis/where-it-hurts/knee-pain/knee-anatomy.php

  10. https://medlineplus.gov/shoulderinjuriesanddisorders.html

  11. https://www.arthritis.org/about-arthritis/where-it-hurts/wrist-hand-and-finger-pain/hand-wrist-anatomy.php

  12. https://www.arthritis.org/about-arthritis/where-it-hurts/elbow-pain/elbow-anatomy.php

  13. https://medlineplus.gov/elbowinjuriesanddisorders.html

  14. http://www.assh.org/handcare/hand-arm-conditions/cubital-tunnel

  15. https://www.hopkinsmedicine.org/healthlibrary/conditions/cardiovascular_diseases/basic_anatomy_of_the_heart_85,P00192

  16. https://medlineplus.gov/heartdiseases.html

  17. https://medlineplus.gov/hernia.html

  18. https://medlineplus.gov/hernia.html

  19. https://medlineplus.gov/gerd.html

  20. https://www.ncbi.nlm.nih.gov/pubmed/18671778 (Ruszniewki, et al. Nonsteroidal anti-inflammatory drug use as a risk factor for gastro-oesophageal reflux disease: an observational study (2008) Aliment Pharmacol Theor.)

  21. Cal. Lab. Code § 3208.3(a).

  22. Cal. Lab. Code § 3208.3(a); California Senate Bill 542 (2019).

  23. State of California, Schedule for Rating Permanent Disabilities (2005).

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