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Personal Injuries: An Insight into the Causes, Damages and Types of Personal Injury

November 23, 2021

Personal injuries are a sad reality that affects not just individuals but also their families. Personal injuries can be caused by negligence, user error, manufacturing defect (defective internal components, low-grade material), manufacturing design issues, poor maintenance of the tools, or installation error (some tools and equipment need to be installed by the user and if not done properly could lead to injury.)

Personal injuries are complex, diverse in nature, and challenging to investigate. We bring to you a detailed guide about the causes and damages of personal injuries and how Origin and Cause analyzes the data and events presented to them to reach scientific conclusions.

How Engineers Assist with Personal Injury Claims

No investigation can be done without the availability of data. At Origin and Cause, we base our findings on facts and evidence. In order to do that, our investigators and engineers will:

1. Gather and analyze all available data
  • This includes gathering background information along with the data available presently
  • A testing protocol is put in place to conduct joint examinations and analysis
  • Opposing reports are reviewed
  • Suggestions are put forward if any further work or investigation is needed
2. Separate facts from opinion
3. Conduct discussions with lawyers/adjusters. This examination can help lawyers and adjusters
  • Expose liable parties by better understanding the circumstances at hand
  • Formulate a sound and compelling strategy while administering a claim

Different Types of Injury Claims

Case Study 1 – Electric Wheelchair

In the first case study, a wheelchair was involved in an accident. The person riding it was on the street where he lost control and the wheelchair sped up. The rider panicked and the joystick controlling the wheelchair came off, causing a complete loss of control. The wheelchair tumbled over and landed on the rider.

The wheelchair was examined by the engineers at Origin and Cause. There was nothing out of place, it was well maintained by the user but the knob of the joystick demonstrated a huge manufacturing design defect. 

(joystick knob)

The knob was not secured to the shaft. There was no evidence of set screws to ensure the knob stays in place. The conclusion drawn was that this was an issue with design deficiency. The user was riding the chair near a radio station and the electromagnetic field created by the radio waves interfered with the motor in the wheelchair.

Case Study 2 – Toilet Structure

The second example covers personal injury occurring to a child in daycare. He was on the toilet when for no apparent reason the material from the side of the bowl was ejected and ruptured one of his arteries. Origin and Cause was asked to determine the cause of the failure of the toilet. 

(Ceramic Toilet)

Toilets are made out of ceramics that are cooked in a furnace. If sintering is administered incorrectly, there could be discontinuities in the material making it act as a stress concentrator. Thorough testing goes into determining why the ceramic failed. The fracture surface was examined, and a cross-section was analyzed under a microscope to determine any abnormalities in the microstructure along with porosity tests.

Standard toilets have a certain level of acceptable porosity. If those levels increase, the part becomes weak which was the case with this particular toilet.  The stresses were locked in for extended periods of time and released energy all of a sudden without warning.  The investigation concluded that the toilet broke due to a manufacturing defect. 

Case Study 3 – Welded Frame Chair

This case study highlights a personal injury caused due to a chair in a public area. A parent was sitting with his baby on his shoulder when the chair broke causing the child to fall headfirst to the ground. 

The chairs were made from tubular steel and the supporting steel was welded together. The supporting bar at the end of the chair failed at the weld. The chair was collected, along with exemplar chairs, to conduct a full metallurgical investigation to understand the mechanics of the material. In a welded structure, the welding should be as strong as the metal itself, if not stronger. 

A visual and microscopic inspection was conducted involving evaluation of the microscopic structures, along with a hardness survey.

(High magnification under a microscope)

The image shows a high magnification of the fracture surface revealing a black void on the left side. The white compound was an impurity found in the material. Weldments cannot have voids and impurities as their presence diminishes the structural integrity, strength, and load-carrying capability of the weld which led to the chair breaking, causing an injury. 

Case Study 4- Tie Rod

This case study showcases the failure of a vehicle’s tie rod (as seen in the image on the right). A collision took place at the front of the vehicle, which resulted in a fatality due to a complete fracture in the tie rod.

The tie rod is a key component of the steering system as it pulls or pushes the wheel to make it turn. If the tie rod fails, one cannot control the vehicle’s direction. Origin and Cause was asked to determine if there were manufacturing defects in the tie rod or what exactly caused it to fail.

(Microscopic view of a tie rod)

The tie rod was put under a powerful microscope to study the fracture surface under a magnification of 500x. An experienced engineer would label these features pictured above as ‘dimples’ that can be associated with ductile overload. Metal components are capable of stretching within their elasticity limit and can resume their original shape. However, if that limit is crossed, the component starts deforming irreversibly.

There are certain failure mechanisms, each with its own characteristics. 

The left image shows a fractured surface that failed due to Fatigue. Fatigue is a failure that occurs over time, progressively due to cyclic stresses. The striations are typical for fatigue failure mode.

The center image depicts an Intergranular Fracture. It is a brittle fracture and occurs at the grain boundary. Each material is made of grains that stick together and the fracture can occur at the boundaries. If the fracture occurs through the grains, it is called a Transgranular Fracture as seen in the image on the right.

The ductility as shown in the image proved that the material behaved as it was intended and that there was no manufacturing defect. The conclusion was that the accident was not caused due to a manufacturing defect. 

Case Study 5 – Bike Frame

This case is about a bike that ruptured, while being used by a child, causing him to fall head-first over the handlebars and sustain serious injuries. The bike showed signs of structural failure and a sample of the bike was brought to the lab for analysis. 

The left image depicts one of the mating fracture surfaces that is flat, which raises a red flag. Upon microscopic examination, striations were observed which proved a failure due to an improperly made weld as a result of manufacturing deficiency. 

Case Study 6 – Tire Rim Cutting

A contractor who was collecting scrap metal sustained injuries to his face. He was collecting aluminum rings by cutting the tire and cutting the ring in four different sections. He was using a reciprocal saw for this procedure, however, while working on this particular tire, the saw kicked back, hitting him in the face.

He claimed the farm owner may have introduced an explosive compound inside the tire. 

The inside samples of the tire were examined which did not show traces of an explosive compound. Upon further inspection, it was revealed that the accident happened due to negligence. The contractor was using the saw to cut through a soft metal and did not adjust the cutting speed and position of the saw when he reached the rim. When he reached the hard metal (the rim), the saw kicked back, causing an injury.

Case 7 – Product Contamination

This case involves chocolate contamination. It did not lead to personal injury but could have caused health effects in the long term. The customers started complaining about a bad odor in the chocolate causing a loss of business for the chocolate maker. Origin and Cause was asked to look into the case as the maker did not change the recipe or the ingredients. 

Chocolate is known to be the strongest odor-absorbing ingredient. A few boxes and chocolate samples were examined along with the packaging. Chocolate boxes from a different batch were provided as well. A comparative chemical analysis of the cardboard cellophane and glue was conducted. It was found that the glue was not certified for use in the food industry. The maker of the boxes had changed suppliers who were using glue not certified for use. The chocolate started absorbing odours and had a glue-like flavour.

Case Study 8 – Walker

An elderly woman was using a walker which broke suddenly, causing her to fall to the ground and sustain injuries to her hip. Origin and Cause looked into what caused the walker to break and it was a portion of the frame that broke off.

It seemed like a straightforward investigation, however, every possible scenario had to be considered including user abuse, poor maintenance or improper use. It was found that there were large welds present throughout. The presence of welds in a mold material such as this is not desirable. It reduces the strength of the component and wears down its capabilities. During normal usage, the frame gave way and fractured. 

Case Study 9 – Ladder

There are a lot of accidents caused by ladders. For the most part, ladders cause injury due to improper use. This could be descending the ladder without facing it, not opening the ladder enough, or placing it on an uneven surface. Oftentimes these accidents can also happen due to manufacturing defects. 

This was a folding ladder that Origin and Cause was asked to look into. While the roofer was descending, one of the hinges broke, causing the roofer to fall to the ground, paralyzing him from the waist down. Origin and Cause had to determine what caused the fracture of the hinge. 

A sample was collected and examined under the microscope. 

(microscopic view of the ladder sample)

The left image, portraying the rounded features, represents gas porosity. While the hinge was being cast, gas was trapped in the molten material with no escape. The presence of gas porosity is undesirable as they are stress concentrators and reduce the load-bearing capabilities of the ladder. 

The right side of the image shows another defect known as shrinkage porosity. During the solidification of cast materials, if the temperature is not uniform throughout the molten metal, one section will solidify faster than the other creating defects.

The examination concluded that the cause of failure was manufacturing defects.

Case Study 10 – Fitness Equipment

Fitness equipment can lead to personal injuries as well. While the user was using the weight lifting equipment, one of the steel cables snapped and one end of the cable hit him in the face. Certified fitness equipment uses standard aircraft cable which is capable of holding significant weight. Each cable differs and depends on the way it was manufactured and each differs in the amount of load it is capable of carrying.

The user claimed that the cable was defective causing it to snap. A small section of the cable was cut from the fractured end and examined under a microscope. 

The right side of the image displays the morphology of the fractured end. This image is typically seen when there is a ductile overload failure. The cable performed as intended until the point its limit was reached, causing it to snap. The conclusion of the investigation was that the accident happened due to user abuse and the user loading more weights than the fitness equipment allowed. This caused additional stress to the cable, causing it to snap.

Case Study 11 – Kitchen Pot

Origin and Cause was asked to investigate a case involving burns caused by a kitchen pot. The bottom of the pot is made up of three layers consisting of a bottom layer of copper, an aluminum layer in the middle, and a copper layer again.

The owner put the pot on and forgot about it. As there was no place for the heat to escape, it started accumulating in the bottom of the pot. The pots are not designed to be heated dry. The aluminum has a lower melting temperature causing the pot to melt and metal to spew out. 

When the owner tried to remove it, she was hit in the chest by the flying particles. It was not a manufacturing deficiency but user negligence. 

Case Study 12 – Dentist Chair

During a routine dental procedure, the articulated arm of the dentist’s chair broke off and landed on the patient’s head, causing severe injuries. 

A sample of the fractured arm was examined under a microscope. It was discovered that the collapse was caused due to a fractured hinge. As depicted in the right image, the fractured surface runs through a threaded hole which acted as a stress concentrator and a weak area. With further examination under the microscope, it was found that the hinge failed due to fatigue due to an improper fastener being used. During a maintenance procedure, the technician used an improper fastener that could not handle the fluctuating stresses of lifting or repositioning the lamp. It was subjected to cyclic stresses causing fatigue. 

Case Study 13- Carbon Monoxide Poisoning

Origin and Cause has been asked to work on cases involving carbon monoxide poisoning. Carbon monoxide poisoning can occur due to a variety of reasons including:

  • Improper installation of gas appliances
  • Lack of proper maintenance/inspection of gas appliances
  • Defective gas appliances
  • Blocked chimney chutes
  • Vehicle exhaust (keeping a car running in an enclosed space) or exhaust gas being ejected into the car due to a maintenance issue

Case Study 14 – Collapse of Structure

Origin and Cause has also inspected and investigated the causes behind the collapse of structures. This includes:

  • The collapse of structures like scaffoldings
  • Collapse due to violation of building codes (unauthorized building structures, addition to a building without permission)
  • Personal fall arrest systems

Origin and Cause: We Have the Expertise to Decode Personal Injuries

After having presented the above case studies, it is clear that our firm has been part of a variety of personal injury cases that were caused due to improper use, violations, manufacturing defect, or material defect. Our engineers and analysts have lended their expertise to hundreds of cases to get to the root cause of the damage or failure based on scientific deductions. Contact us at 1-888-624-3473 if you are dealing with personal injuries and we can help you determine the cause of the failure.