Designers of hydraulic and pneumatic systems are frequently left scratching their heads after juries return large verdicts against them, where the customer foolishly exposed himself to an obvious danger and was injured or killed by that equipment. Should a manufacturer or designer be held responsible in those cases? Maybe not.

In certain cases, many courts will prevent a plaintiff from recovering on his claim under a legal defense known as "assumption of the risk." Where a plaintiff claims that a product was sold in a defective condition and was unreasonably dangerous to the consumer, that claim may be defeated if the defendant can prove that the plaintiff assumed the risk of his injuries because he recognized and understood the dangerous condition of a product and, yet, voluntarily and unreasonably proceeded to use the product in disregard of a known danger.

Different cases, different results
Consider the following two hydraulic lift cases. In the first case, an experienced maintenance mechanic was working underneath a scissor-style hydraulic lift, attempting to remove two leaking hydraulic cylinders for repair. He was supplied with a safety leg for use in securing the lift during repairs and a service manual containing instructions on the proper use of the safety device. The sides of the lift displayed a warning that safety devices should be in place before work was performed.

The mechanic did not place the safety leg in its intended spot. Instead, he raised the lift and secured it by placing the safety leg along one side of the lift and a heavy piece of timber along the opposite side. While attempting to remove the hydraulic cylinders, the lift fell, killing the worker. The trial court dismissed the case against the designer and manufacturer, noting that there was nothing for a jury to consider, since the mechanic had clearly assumed the risk of his actions.

In another hydraulic lift case, the result was different. There, the lift had leaking fluid problems and would sporadically, without warning, shift upward or downward. The safety pins designed to stop the lift from shifting downward had broken off or did not work. While the mechanic was working under the lift, it suddenly shifted downward. In order to avoid being struck, he moved quickly from under it, and slipped on hydraulic fluid that had leaked from the lift's cylinders. He sustained permanent head and back injuries.

Here, the court said that the case would not be dismissed, but that a jury needed to decide whether the mechanic had assumed the risk of his actions. There was a question as to whether the risk the mechanic faced was indeed voluntary, since he was required to use the lift to perform his job. The court also questioned whether the risk was truly known by, or obvious to, the mechanic, since the previous shifting of the lift was sporadic and not constant.

What did the worker know?
The assumption of the risk standard is typically a subjective one. The courts look to what a particular person using the equipment in fact sees, knows, understands, and appreciates in determining whether he or she assumed the risk. For example, a jury returned an award in favor of a worker who operated a backhoe that was fitted with a pneumatic hammer and chisel, which were used to break up concrete on a bridge roadbed. The operator performed this job for a week, during which the hammer began to wear, resulting in it losing its smooth rhythm. Instead, it jolted and shook the worker who had operated a backhoe for 30 years. The operator complained about the joltings to his superintendent, who told the operator to be patient, as a replacement hammer would arrive in a few days. Days later, the worker finally reported that he could not continue because the "shaking up ... was too much for my back." The worker later underwent surgery, resulting in the removal of a ruptured disk in his lower back.

The defendant argued that the jury's award should be overturned, because the worker was very experienced, complained of the jolting and back pain for days, and must have assumed the risk of injury by his actions. The court of appeals allowed the jury verdict to stand, stating that the victim must not only know of the facts that created the danger, but must also comprehend and appreciate the danger itself. The court noted that a worker's complaint about his back — as well as his willingness to report for work — does not conclusively establish that the worker must have known he was running the risk of the injury he sustained.

Although the courts are not always eager to protect the manufacturer or designer from liability based on a defense of "assumption of the risk," they have done so in certain cases. One such case involved a worker of trenching equipment that was converted to bore holes under streets. The boring device was connected to the trencher. A long auger rod was then connected to the boring device. Due to the length of the rods, they would bend upwards, instead of remaining horizontal when they hit a solid object. The rod had buckled in this manner several times.

One fateful day, the equipment operator observed the rod buckle and decided to stand on the exposed part of the rod, which rotated to cause the boring action. The worker stood on the exposed part of the rod pursuant to an order given to him by his supervisor. With the worker standing on the rod, the operator reversed the direction of the rotating rod, resulting in injury and ultimate amputation of the worker's leg below the knee.

The case against the manufacturer of the trencher was dismissed. The court accepted the assumption of the risk defense, and observed that the worker admitted he had stood on the rod on several other occasions, understood that doing so was dangerous, and that an accident could happen by standing on the rod.

As these cases demonstrate, the assumption of the risk defense may not always be available to protect a manufacturer or designer from liability where an injury occurs. However, it is prudent to thoroughly investigate the facts surrounding an accident to determine whether the operator is to blame for foolish behavior and not permit the manufacturer or designer to serve as an improper scapegoat.

Pete C. Elliott is the vice-chairperson of the Trial Department at Benesch, Friedlander, Coplan & Aronoff LLP in Cleveland, and is the team leader of its Fluid Power Defense Group. Contact Elliott at