Tag Archives: biomechanics

Dr. John Lloyd has served attorneys nationwide for 25+ years in biomechanics, human factors, helmet testing and motorcycle accident expert

Admissibility of Biomechanics Testimony on Causation of Injury

On the admissibility of biomechanics testimony the Reference Manual on Scientific Evidence, written jointly by the National Academies of Sciences, Engineering and Medicine and the Federal Judicial Center, states: “Specifically, one cross-disciplinary domain deals with the study of injury mechanics, which spans the interface between mechanics and biology. The traditional role of the physician is the diagnosis (identification) of injuries and their treatment, not a detailed assessment of the physical forces and motions that created injuries during a specific event. The field of biomechanics (also called biomechanical engineering) involves the application of mechanical principles to biological systems, and is well suited to answering questions pertaining to injury mechanics.” In the case Garner v Baird [910 N.Y.S.2d 762, 762 (N.Y. Civ. Ct. 2010)] defined biomechanics as “the application of physics and mechanical engineering to the human body.”

In a ruling of the 1st District Court of Appeals of Florida on July 19, 2012 [98 So.3d 115, Florida First District Court of Appeals, 2012] Judge Healey concluded, “that biomechanics expert, Dr. John Lloyd is qualified to offer opinions as to causation because the mechanism of injury fell within the field of biomechanics”. Moreover, in the case of Taylor v Culver Florida First District Court of Appeals, 2015 the appeals court ruling, which directly references Council states “the proffered testimony of the Appellant’s biomechanics expert was relevant to the disputed issues concerning velocity and direction of forces involved in the accident”. In the case Maines v Fox [190 So.3d 1135, Florida First District Court of Appeals, 2016], the ruling states: “Biomechanical opinions as to the general causation of a type of injury are admissible in a personal injury case.”

Biomechanical Analysis Athletic Protectors – Case Study

A male high-school athlete was participating in a team sport when a player from the opposing team attempted a goal. The male athlete was the only obstacle between the opposing player and a winning goal. The high speed shot, taken from less than 10 feet away, impacted the male athlete directly in the groin. He immediately fell to his knees in pain. Thankfully, he was wearing an new athletic protector (known colloquially as a “jockstrap”), which should have prevented injury even at such close quarters. Dr. John Lloyd was retained to perform a biomechanical analysis athletic protector.

lacrosse athletic protector

The athlete sat out the remainder of the game. Later that evening he became concerned as the swelling continued. The following day tests revealed that amputation of one of his testicles was medically necessary. As a young man, with his whole life ahead of him, the physical and emotional pain of losing a testicle was almost unbearable.

The young man had conducted his research before purchasing the new athletic protector. The packaging had promised comfort and protection. Why then did he sustain this life-changing injury?

Athletic protector biomechanics expert Dr. John Lloyd, was retained to evaluate a potential product liability case.

It was quickly discovered, interestingly, that there are no American Standards on the performance requirements of athletic protectors. Therefore, Dr. Lloyd devised a test method to evaluate exemplars of the subject jockstrap with comparison to models sold by other product manufacturers.

athletic protector testing

Balls were shot at various speeds from a pitching machine aimed at the athletic protectors affixed to a male mannequin. Each impact was recorded using a high-speed video camera, while Dr. Lloyd’s associate, standing behind the mannequin, measured the speed of each impact using a radar gun. A total of 70 tests were performed.

As the following high-speed video recording shows, the subject athletic protector deforms completely upon impact, providing the wearer with little, if any, protection from injury.

Several new design models also collapsed upon impact, while others cracked and broke

collapsed athletic protector
cracked athletic protector

broken athletic protector

Fortunately, the old style jock strap with which many of us are familiar was among the few models that held up to impact and actually provided adequate protection.

old athletic protector
old athletic protector testing

Based on biomechanical analysis I concluded, to a reasonable degree of scientific certainty, that the subject athletic protector provides inadequate protection of the male genitalia from injury associated with impact from a moderate speed ball. This conclusion is based on evidence of extreme deformation of the jock strap upon direct impact from a ball. 

Had the manufacturer evaluated their product under real-life conditions, as described herein, they would have learned that this product provides inadequate protection against injury to the male genitalia.  Further, comparative testing of other available athletic protectors identified products that provide better protection.

Biomechanics

Biomechanics (1899) is derived from the Ancient Greek bios “life” and mēchanikē “mechanics”, to refer to the study of the mechanical principles of living organisms, particularly their movement and structure. The earliest known reference to the study of biomechanics dates back to Aristotle (384– 322 BC), who published ‘De Motu Animalium’ (On the Motion of Animals), in which he presented the mechanical concept ‘Ground Action Force’ as a starting point to deliberate where movement comes from.Dr John Lloyd biomechanics biomechanist

The science of biomechanics has come a long way since the days of Aristotle. Contemporary biomechanics involves the application of Newtonian mechanics to determine physical capabilities and limitations of the human body. Trauma biomechanics examines whether mechanical forces acting on and within the human body may be sufficient to cause injury. The science of biomechanics is highly accepted by the courts for the purpose of explaining the mechanical causation of injuries.

Biomechanists posses advanced knowledge of human anatomy, mathematics and physics. We use this knowledge to study failure thresholds of human tissue, bone, ligaments, blood vessels, etc. When applying this knowledge to litigation, a biomechanist will perform a reconstruction to determine the forces acting on the plaintiff during the claimed injury-causing event and relate those forces to thresholds of injury. Biomechanists and Medical Doctors serve complementary roles in the medico-legal system. However a biomechanist is uniquely qualified, based on education, training and experience, to determine injury causation.

The methods that I use in my biomechanical evaluations are similar to methods that have been employed by other researchers and are generally accepted by experts in my field. Such methods have been validated and published in peer-reviewed scientific journals.

Expert in Injury Biomechanics

Dr. John Lloyd has served as a biomechanics expert for both defense and plaintiff’s counsel on hundreds of cases throughout the United States involving automobile collisions, motorcycle accidents, trucking crash as well as slips trips and falls. Dr. Lloyd is available to travel to investigate the causes of such cases. Based on his doctorate in ergonomics with a specialization in biomechanics, Dr. Lloyd can assess whether the claimed injuries meet or exceed known biomechanical thresholds of injury.

Please call Dr. Lloyd at 813-624-8986 or email DrJohnLloyd@Tampabay.RR.com to discuss how he can be of assistance with your case.

NI Week features John Lloyd football helmet expert

Football helmet expert, Dr. John Lloyd,  had the privilege to present his research on football helmets as part of the Keynote address at the National Instrument conference in Austin, TX this week. The audience of 5,000+ attendees learned about Dr. Lloyd’s research into biomechanics of the brain.

 

It has been said that helmets cannot prevent concussions. I disagree.

As a biomechanist I have dedicated my career to studying the biomechanics of brain injuries. There are two key mechanical forces that give rise to head and brain injuries (1) linear forces, which are responsible for visible injuries, including bruising and skull fractures, and (2) rotational forces, which cause invisible injuries, such as concussion and brain injury.

Since helmets are currently designed to pass testing standards that focus on linear forces only, it is no surprise that helmets have limited benefit in preventing concussions. Through advances in medicine we have learned that concussions can potentially have life-long neurological consequences, including memory impairement and personality changes / behavioral effects.

Over the past years I have developed and validated a testing method to evaluate helmets in terms of their ability to protect against both linear and rotational forces. Using this apparatus I characterized football helmets, results of which have been submitted to Science for publication.

Based on lessons learned from my biomechanical evaluation of various sports helmets, I have devised a matrix of shear-thickening non-Newtonian materials. A prototype helmet was constructed using this matrix liner, results of which show that rotational forces that cause concussion and other brain injuries are reduced by up to 50% compared to a leading football helmet, while also reducing linear forces.

Football helmet expert Dr. John Lloyd

helmet prototype reduces concussion risk

It is my goal and my passion to work with leading helmet companies to make this technology available to players and sports participants of all aged to enhance their protection against brain trauma. I am looking to collaborate with one manufacturer in each sport to offer an exclusive license patent-pending technology.