Shoulder Injuries

Causes Of Shoulder Injuries

The human shoulder joint is prone to a wide variety of injuries. On the job shoulder injuries fall under the two general categories of either a single specific harmful event, or cumulative trauma from work wearing down the shoulder over time.

Frequently, a shoulder injury develops from a combination of work activity and pre-existing problems from aging, degeneration, and activities outside of work. Certain types of work movements tend to cause shoulder problems. Jobs that require a worker to reach over their heads are more likely to cause an injury. Jobs in which employees work with their arms extended are also more problematic.

The shoulder can also be injured in situations where a worker falls and catches themselves and puts unusual strain on the shoulder joint. However, shoulder injuries can also occur on the job from relatively low stress movements and activities.

Types Of Shoulder Injuries

The shoulder joint is a wonderful piece of engineering that gives us the ability to move our arms in a wide range of motion. However, the shoulder joint is also very complex and a lot can go wrong.

The bony parts of the shoulder joint are the upper arm (the humerus), the shoulder blade (the scapula) and the collar bone (the clavicle). These bones fit together fairly loosely to allow the arm to move in a wide range of motion. The shoulder bones are held together and manipulated by an intricate system of ligaments, tendons and muscles.

The ligaments are the soft tissue components that connect the bones together. The glenohumeral ligaments provide stability between the bones of the shoulder and are probably the most frequently injured ligaments of the shoulder.

The shoulder tendons are the structures that attach the muscles to the bones. The shoulder has two main sets of tendons. First, there are four different rotator cuff tendons that connect the rotator cuff muscles to the upper arm bone. Second, the bicep muscle has two different tendons that attach to the shoulder bone. These are called the short head biceps tendon and the long head biceps tendon. The long head biceps tendon tends to be injured more frequently.

The shoulder has many different muscles which power and move the shoulder and arm. The most important muscles of the shoulder, and the most frequently injured, are the rotator cuff muscles. There are four separate rotator cuff muscles: the supraspinatus, the subscapularis, the infraspinatus and the teres minor.

The glenoid labrum is another structure of the shoulder that is frequently injured. The glenoid labrum is a type of cartilage that helps hold together the connection between the upper arm and the shoulder blade.

In Iowa work comp cases the most frequent injuries are tears of the rotator cuff muscles or tendons, impingements of the acromioclavicular joint, tears of the labrum, and tears or detachment of the biceps tendons.

Iowa Workers’ Compensation Law On Shoulder Injury Liability

Under Iowa workers’ compensation law a worker is entitled to be paid for a shoulder injury if work activities were a substantial cause of the injury.

In many shoulder injury cases the primary dispute between the worker and the employer and work comp insurance company is whether work was a substantial cause of the shoulder injury; or whether the shoulder injury was really caused by natural degeneration, the aging process, or a worker’s activities outside the job. Iowa law does recognize and provide that a worker is entitled to compensation even if there were pre-existing problems with the shoulder, as long as work was a substantial aggravating factor, and the resulting injuries and problems from the job activities resulted in a permanent and material aggravation of the pre-existing condition.

Iowa Work Comp Law On Compensation For Shoulder Injuries

Shoulder injuries fall under the category of unscheduled injuries. This means that the amount of compensation which is paid for a shoulder injury is based on the effect of the injury on an injured worker’s potential future earning capacity. In assessing a worker’s loss of potential earning capacity from a shoulder injury a wide variety of factors need to be examined, including:

  • The age of the injured worker. Generally, an older worker will receive a higher award than a younger worker for the same injury. The reasoning behind this rule is that most employers would prefer younger workers anyway, and an older worker with a shoulder injury is at even more of a disadvantage in getting hired.
  • Education. As a general matter workers with a lower level of education will receive a higher award than workers with more education. The reasoning behind this rule is that a worker with more education usually has a better chance of being able to find a job where any limitations from a shoulder injury are not as important.
  • Job qualifications and job experience. A higher level of work skills and a broader amount of work experience will generally lead to a lower award. The reasoning behind this rule is that more highly skilled workers have a better chance of overcoming a physical disability.
  • Motivation. Injured workers who are motivated to get back to work and who put in the effort to return to the workforce generally are compensated at a higher level than workers who do not make the effort to rehab from their injuries and get back to work.
  • Loss of actual earnings. Under Iowa law if an injured worker’s earnings remain the same or even go up after a shoulder injury, that worker is still allowed to receive workers’ compensation benefits. However, cases in which the injured worker actually suffers lower earnings because of their injury will generally lead to a higher compensation award.
  • Functional impairment from the injury. Functional impairment means the degree or percentage of physical disability that a doctor finds is caused by the injury. For shoulder injuries this percentage of impairment can be expressed either as an impairment of the upper extremity or an impairment of the body as a whole. The employer and insurance carrier have a duty to obtain such an impairment rating once the worker reaches maximum medical improvement from the treatment. A worker is also entitled to have a doctor of their choice perform an evaluation of the extent of the impairment from the shoulder injury. This is called an independent medical exam, or IME. Generally a higher functional impairment rating will lead to a higher work comp payment.
  • Work restrictions. After a worker has gone through treatment and rehabilitation for their shoulder injury the treating doctor will generally issue permanent work restrictions. A worker may also be given additional permanent work restrictions as a result of the independent medical exam process. Workers with more stringent and limiting work restrictions will generally receive higher awards than workers who have minor restrictions or no restrictions.
  • Inability to engage in employment for which the worker is suited. As a result of a shoulder injury a worker in a physical job such as carpentry might completely lose their ability to return to carpentry work. On the other hand, another carpenter with a shoulder injury might end up with restrictions that prevent them from doing 100% of their prior job, but they are still able to return to doing most of the carpentry work that they had done before the injury. The first worker who is completely prevented from returning to their prior work will generally receive more compensation than a worker who can return to doing most or all of their previous job.
  • Whether the employer continues to provide the worker a job. If the employer fires or terminates the worker after the shoulder injury that will generally end up resulting in a higher compensation award for the worker. In contrast, if the employer accommodates the worker’s problems from the shoulder injury and continues to employ the worker that will usually lower the value of the injury.

No one factor controls how a worker’s shoulder injury will be valued. Figuring out how much a shoulder injury is worth is much more complex than plugging numbers into a formula. All the relevant factors have to be weighed and analyzed to determine how much a shoulder injury has reduced a workers’ potential future earning capacity.

How We Can Help On Shoulder Injury Cases

In all cases involving unscheduled injuries, including shoulder injuries, there are frequently many areas of disagreement between the injured worker and the employer and work comp insurance company. Therefore, it is very important to find a lawyer that will do all the necessary research and preparation to address the disputed issues.

Our lawyers have extensive experience in litigating all types of Iowa workers’ compensation cases including shoulder injuries. See the section on “Benefits of Hiring Our Lawyers” for an explanation of 17 of the biggest ways that our lawyers help our clients.


Call or email us now, and our lawyers will be happy to talk to you about your shoulder injury case or any other Iowa workers’ compensation injury, and answer your questions without charge or obligation.