There are over 100,000 ladder accidents annually in the U.S. requiring hospital emergency room treatment. Although many of these result from user misuse, such as an improper extension ladder lean angle against a wall causing it to slip outward, use of a damaged ladder, or failing to lock a step ladder's spreaders, many ladders fail due to design or manufacturing defects. Many are designed too flexibly and some extension ladders are equipped with inferior rung locks. Other defects can be introduced during manufacturing such as material flaws or improperly seated rivet attachments. In addition, the fine-print warnings and instructions, on most ladders, are hard to read.
Expertise
Questions Answered
We are active participants on the ANSI Ladder Standards Committee and have:
Published papers regarding ladder hazards
Conducted ladder structural testing and research
Developed computer analyses to simulate ladder behavior
Cited causes of false locking of extension ladders
Case Examples
Falls From Stepladders:
We have investigated numerous stepladder accidents involving unexplained falls where no obvious structural defect can be found. When a ladder is too flexible, a climber may inadvertently cause the rear legs to shift sidewise, raising one of the legs off the ground. Later, when the user shifts his weight, the raised leg suddenly strikes the ground causing him to loose his balance and fall. In several cases, we have demonstrated how modest side rail stiffness improvements can reduce this problem.
Dr. Irving Ojalvo is Chairman of Technology Associates (www.technology-assoc.com), a forensic engineering firm with offices in New York City and Connecticut. The firm's technical personnel, all of whom have advanced degrees, perform accident reconstruction involving issues of biomechanics, mechanical, traffic, and human factors engineering.
