Tag Archives: human factor expert witness

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

Human Factors

Human Factors Engineering (aka Ergonomics) is the science of work, derived from the Greek ergon (work) and nomos (laws) .  Human Factors is a systems-oriented discipline which extends across all aspects of human activity, drawing on a number of scientific disciplines, including physiology, biomechanics, psychology, anthropometry, industrial hygiene, and kinesiology (U.S. Dept. of Labor, 2000)

  • Physical ergonomics is concerned with human anatomical, anthropometric, physiological and biomechanical characteristics as they relate to physical activity.
  • Cognitive ergonomics is concerned with mental processes, such as perception, memory, reasoning, and motor response, as they affect interactions among humans and other elements of a system.

human factors

Dr. John Lloyd attended Loughborough University in England, where he attained a BSc. with Honors in Ergonomics (1992) and Ph.D. in Ergonomics (2002). Loughborough University is considered a premier academic institute for the study of Ergonomics / Human Factors and is currently ranked #4 University in the UK, behind Oxford and Cambridge.

In addition, Dr. Lloyd has held the distinction of Board Certification since 1995 and is a member of the Human Factors and Ergonomics Society as well as the American Society of Biomechanics.

Dr. Lloyd has been accepted by the courts in Florida and other states as an expert in Human Factors and has provided testimony on:

Distracted Driving Texting

Distracted driving is any activity that diverts attention from driving, including talking or texting on your phone, smoking, eating and drinking. I have even seen people putting on makeup and shaving their face while driving!Lloyd human factors expert distracted driving texting

Texting is the most alarming driver distraction. Sending or reading a text takes your eyes off the road for 5 seconds or more. At 40 miles per hour a car can travel the length of a football field in 5 seconds; at highway speeds, a vehicle can travel the length of almost two football fields in the same time.

Texting while driving and other cell-phone reading and writing activities are high-risk activities associated with motor vehicle collisions and mortality. In 2015 alone 3,450 people were killed on US roads. 391,000 were injured in motor vehicle crashes involving distracted drivers.

There are three types of driver distractions – manual, visual and cognitive.

  • Manual distractions cause you to take your hands off the steering wheel
  • Visual distractions cause you to take your eyes off the road
  • Cognitive distractions interfere with your mental focus on driving

Texting involves all three of the above distractions and is therefore considered a high risk activity while driving.

Motorcycle Accident Expert in Biomechanics and Human Factors

Motorcycle Accident Expert

Motorcycle collision analysis is a highly specialized discipline in which Dr. Lloyd is eminently qualified as a motorcycle accident expert. In addition to holding a PhD in Ergonomics (Human Factors), with a specialization in Biomechanics, John has more that 20 years and 200,000 miles of experience riding motorcycles. John-Lloyd-motorcycle-accident-expertDr. Lloyd has completed numerous advanced programs, including Motorcycle Safety Foundation (MSF), Experienced Rider Course and Total Rider Tech Advanced training.

Motorcycle Helmets and Brain Injury

To consider whether a motorcycle helmet might reduce the risk of brain trauma in a motorcycle accident it is first important to understand the two primary mechanisms associated with traumatic brain injury – impact loading and impulse loading.

Impact loading involves a direct blow transmitted primarily through the center of mass of the head, resulting in extracranial focal injuries, such as contusions, lacerations and external hematomas, as well as skull fractures. Shock waves from blunt force trauma may also cause underlying focal brain injuries, such as cerebral contusions, subarachnoid hematomas and intracerebral hemorrhages. Whereas, impulse or inertial loading caused by sudden movement of the brain relative to the skull, produces cerebral concussion. Inertial loading at the surface of the brain can cause subdural hemorrhage due to bridging vein rupture, whereas if affecting the neural structures deeper within the brain can produce diffuse axonal injury (DAI).

Holbourn was the first to cite angular / rotational acceleration as an important mechanism in brain injury. Gennarelli, Thibault, and colleagues, in a series of studies using live primates and physical models investigated the role of rotational acceleration in brain injury. They concluded that angular acceleration contributes more than linear acceleration to brain injuries, including concussion, axonal injury, and subdural hematoma.

Motorcycle Helmet Testing

Traditional testing of motorcycle helmets focuses on reducing the effect of linear impact forces by dropping them from a given height onto an anvil and measuring the resultant peak linear acceleration. According to the Federal Motor Vehicle Safety Standard (FMVSS) 218, commonly known as the DOT helmet standard, the test involves dropping a motorcycle helmet onto a flat steel and hemispherical anvil at an impact velocity of 6.0 m/s (13.4mph).   In general, if peak linear acceleration is less than 400g, the helmet is considered acceptable. Current motorcycle helmet testing standards do not incorporate measures of angular acceleration and therefore do not address whether any helmets can provide adequate protection against catastrophic brain injuries, such as concussion, axonal injury and subdural hematoma.

In 1995, the European Commission Directorate General for Energy and Transport initiated a Cooperative Scientific and Technical Research (COST) program to investigate Motorcycle Safety Helmets. Several agencies from Finland, the United Kingdom, France and Germany participated in this study, which compiled and analyzed data from 4,700 motorcycle fatalities in Europe, each year. The COST report documents that 75% of all fatal motorcycle accidents involve head injury. Linear forces were present in only 31% of fatal head injuries, while rotational forces were found to be the primary cause in over 60% of cases. Within the scope of this study experiments were performed using drop tests with accelerometers to measure linear and rotational accelerations of the brain and skull mass associated with different types of impacts. These tests confirmed rotational acceleration to be a primary cause of brain injury in helmeted motorcycle accidents.

John-Lloyd-motorcycle-accident-expert-helmet

  • Rotational forces acting on the brain are the underlying cause of traumatic brain injuries.
  • Motorcycle helmets, including those certified under DOT and SNELL standards are designed to mitigate forces associated with linear acceleration.
  • Motorcycle helmets are not currently certified under either DOT or SNELL standard against their ability to protect against the angular / rotational forces.
  •  Epidemiologic evidence from the COST-327 report  indicates that motorcycle helmets do not provide adequate protection against closed head and brain injuries

Human Factors of Motorcycle Accidents

Human factors in vehicle collisions include all factors related to drivers and other road users that may contribute to a collision. Examples include driver behavior, visual and auditory acuity, decision-making ability, and reaction speed. A 1985 report based on British and American crash data found driver error, intoxication and other human factors contribute wholly or partly to about 93% of crashes.

Motorcycle Inspection

Motorcycle accident analysis often requires involves a teardown and careful inspection of the machine to investigate for possible contributing factors. Our engineers have a combined 70 years experience with motorcycle mechanics.

John Lloyd motorcycle accident expert inspection

A thorough evaluation includes inspection of tires, brakes, suspension setup, electrical components as well as any aftermarket parts.