Cumulative Trauma and Repetitive Stress Injuries


Cumulative trauma and repetitive stress injuries can occur in every type of job. Office workers, factory workers, construction workers, and almost every other type of worker in the economy face the risk of developing a cumulative trauma or repetitive stress injury.

Some of the factors that create an increased risk of a worker suffering a cumulative trauma or repetitive stress injury are:

  • High production requirements. In many fields workers have very high and closely monitored production requirements. This can relate to the speed of the line, the number of bricks that must be laid per day, the number of phone calls that must be made every shift, or the number of key strokes that must be made every hour. These production requirements can go beyond the physical limits of some or all of the employees and lead to cumulative trauma injuries.
  • Heavy lifting.
  • Frequent Lifting.
  • Repetitive gripping.
  • Repetitive hand motions.
  • Forceful hand motions.
  • Work with vibrating tools.
  • Job tasks that involve lifting and twisting at the same time.
  • Having to lift loads too far away from your body.
  • Working too many hours per day or per week.
  • Insufficient rest time.
  • Insufficient rotation between different jobs or tasks.
  • Work requiring awkward posture or body positions.
  • Jobs requiring the worker to stay in the same body position without moving or resting for long periods of time.
  • Repetitive job tasks.
  • Poorly designed tools.
  • Poorly designed work stations.
  • Frequently needing to perform overhead work or work with your arms extended.
  • Standing in one position for a long period of time.
  • Frequent reaching.
  • Awkward lifting.
  • Jobs that require a great deal of bending, twisting and reaching.
  • Intensive word processing.

Cumulative trauma or repetitive stress can lead to injuries to almost every body part. Some of the most common injuries that result from cumulative trauma or repetitive stress are:

  • Neck injuries; including damage to tendons, muscles and nerves; or spinal disc injuries such as protrusions, bulges or herniations.
  • Shoulder injuries; including damage to the rotator cuff, the acromioclavicular joint, the labrum, and the biceps tendon.
  • Thoracic Outlet Syndrome. With this problem nerves from the spine that help control the arms, and sometimes blood vessels from the heart that feed the arms are compressed. The result is numbness in the fingers and the sensation that the injured worker’s hand or arm is asleep.
  • Lower back injuries; including damage to tendons, muscles, and nerves; or spinal disc injuries such as protrusions, bulges, or herniations.
  • Nerve Entrapment Syndrome. Three nerves that frequently end up being entrapped are the median nerve, the ulnar nerve, and the radial nerve. Entrapment of the median nerve at the wrist is called carpal tunnel syndrome. The entrapment of the median nerve in the forearm is called pronator teres syndrome. Entrapment of the ulnar nerve at the elbow is called cubital tunnel syndrome.
  • Tendinitis. Tendinitis in the wrist area is the most common, but tendinitis can also frequently develop at the elbow or the shoulders.
  • Tenosynovitis. This condition involves an inflammation of the nerve sheath and can result in hand pain and numbness.
  • De Quervain’s Syndrome. This is a particularly common form of tenosynovitis.
  • Raynaud’s Disease. This condition causes numbness and pain and tingling of the hands and fingers. One of the distinguishing features of Raynaud’s Disease is that the injured person usually develops sensitivity to cold.
  • Arthritis of the basal joint of the thumb.

Workers in Iowa who are injured by a single event such as a motor vehicle accident while on the job are entitled to receive work comp benefits. However, Iowa law does not require that an injured worker be able to point to a single specific event or moment that caused their injury. Iowa workers’ comp law allows employees that have been injured through cumulative trauma and repetitive stress to recover workers’ compensation benefits.

Iowa law also provides that even if an injured worker had a pre-existing problem, if cumulative trauma or repetitive stress from work substantially increases the disability from the pre-existing injury, then the worker is entitled to compensation for the increased disability.

Time limits apply to cumulative trauma cases, and the nature of the slowly developing injuries creates some special legal issues. The worker is required to give notice of an injury to the employer within 90 days of the occurrence of the injury. Iowa work comp law also has a second time requirement; and an injured worker must file a Petition for workers’ compensation benefits within two years of the date of injury if the worker has never been paid weekly benefits, and within three years of the date of last payment of weekly benefits if such payments have been made.

The nature of cumulative trauma or repetitive stress injuries that develop over time can create quite a few problems and controversies in determining what is the actual injury date. Figuring out the correct injury date is critical because the injury date triggers the start of the time period for giving notice and filing a worker’s compensation Petition. Iowa law provides that the date of injury for cumulative trauma and repetitive stress injuries is the date on which the disability from the injury manifests itself. Manifestation is defined as the date on which it would be apparent to a reasonable person that:

  1. They had suffered an injury;
  2. The injury was caused by the worker’s employment; and
  3. The injury is serious enough that it will have a permanent and adverse impact on the worker’s employment.

The work comp judges are given quite a bit of discretion in deciding what should be the manifestation date. Although there are no firm rules in choosing a manifestation date, important factors are whether the worker had to miss work because the condition prevented them from doing their job, or whether the worker received substantial medical care as a result of the cumulative trauma or repetitive stress.

The injured worker always has the burden of proof to show by a preponderance of the evidence that cumulative trauma or repetitive stress from work was a proximate cause of their injury. Work is considered to be a proximate cause of the injury if it is a substantial factor in bringing about the injury. Work does not have to be the only cause of the injury. For legal purposes a preponderance of the evidence is defined as when the causal connection of work to the injury is probable rather than merely possible. This basically means that a worker has to show that there is at least a 51% chance that cumulative trauma or repetitive stress from work was a substantial factor in causing the resulting final injury.

The workers’ compensation judges and the Iowa Appellate Courts have ruled that expert testimony is almost always necessary in order to establish that cumulative trauma or repetitive stress from work caused an injury. The Workers’ Compensation Commissioner and the Courts also recognize that the testimony of the worker and other non-expert witnesses can be used to support or attack expert testimony. In cumulative trauma or repetitive stress injury cases each side will usually present expert testimony in their favor. The Courts have consistently found that it is up to the Workers’ Compensation Commissioner to decide which side’s expert testimony should be accepted.


Employers and insurance companies may deny a worker’s claim that they suffered an injury from cumulative trauma or repetitive stress for a wide variety of reasons. The defendants may argue that activity outside of work such as hobbies actually cause the injury. Defendants may also blame a worker’s advancing age.

The employer or insurance company may use the opinions of medical experts who believe that factors such as gender, pregnancy, smoking, or other personal health conditions of an injured worker are the actual cause of a resulting injury.

Some employers also rely on ergonomics or human factors engineering to design their workplace, and believe that these efforts eliminate the risk of their workers developing a cumulative trauma or repetitive stress injury.


Our lawyers have litigated many Iowa workers’ compensation cases involving cumulative trauma and repetitive stress over the years. We have a great deal of experience in working with the medical experts, ergonomic experts, and vocational assessment experts to do the best possible job for our clients.

If it is possible to negotiate a reasonable settlement our lawyers have extensive experience in obtaining the type of settlement and the specific release terms that will best suit each client. If a reasonable settlement is not possible, then our lawyers are ready, willing and able to take the case to trial and pursue any necessary appeals.


We would be happy to answer any questions you have about cumulative trauma or repetitive stress injuries, or any other issue in Iowa workers’ compensation cases. Call or email us now without charge or obligation.