Injury Biomechanics. Clearly Explained.

Forensic engineering, accident reconstruction, and injury severity assessment that helps attorneys understand causation and prepare for trial.

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WE HELP ATTORNEYS ANSWER THE HARDEST BIOMECHANICAL CAUSATION QUESTIONS

Deep Academic and Forensic Expertise Across Multiple Disciplines Sets Hayes + Associates Apart

Hayes + Associates combines rigorous biomechanics, engineering analysis, and trial testimony to help attorneys answer the hardest causation questions. We work across catastrophic injury cases, disputed low-severity incidents, and everything in between.

Led by Wilson C. “Toby” Hayes, Ph.D., H+A brings together senior, complementary expertise in biomechanics, orthopaedics, engineering, reconstruction, tribometry, and fall analysis. The team supports plaintiffs and defendants in civil and criminal matters in state and federal courts, providing opinions that are scientifically grounded, strategically useful, and clearly explained to counsel, judges, and juries. Erik D. Power, P.E. leads our Accident Reconstruction team, testifying as an expert in mechanical engineering and biomechanics.

Learn More About Hayes + Associates

100 years of collective forensic experience

300+ peer-reviewed publications & books

90% of new matters from repeat clients & referrals

All Anatomic Regions.
All Injury Severities.
All Causes.

PRACTICE AREAS

From minor collisions and disputed soft-tissue claims to catastrophic trauma, product cases, workplace incidents, falls, shootings, assaults, and abuse matters, H+A has encountered nearly every way injuries occur.

Vehicle Collisions

Reconstruct collision dynamics, evaluate severity and occupant motion, and determine whether claimed injuries are consistent with the event.

Worker Safety

Analyze task demands, workplace forces, loading, vibration, and the relationship between work activity and injury.

Premises Safety

Examine site conditions, design, maintenance, codes, and environmental factors that may have contributed to an incident.

Sports & Recreation

Evaluate equipment, motion, loading conditions, and injury mechanisms in athletic and recreational settings.

Falls

Reconstruct movement from initiation through impact and rest using physical evidence, video, testing, and biomechanical analysis.

Criminal Matters

Reconstruct event dynamics and injury mechanisms in shootings, assaults, use-of-force matters, and abuse cases.

Products Liability

Evaluate product design, manufacture, and warnings to determine whether a defect contributed to the claimed injury.

Explore the matters H+A supports and the case examples behind its analysis.

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Cutting-edge tools.
Expected outcomes.

SERVICES

H+A supports matters from early evaluation through deposition and trial, integrating investigation, reconstruction, biomechanics, and visual communication in one coordinated workflow.

Document incident locations, preserve critical evidence, and ground later opinions in direct observation.

Site Inspections

Retrieve and analyze event data recorder information to evaluate vehicle motion, timing, and collision severity.

Black Box Downloads

Analyze event sequence, movement, forces, and physical evidence to determine how an incident occurred.

Accident Reconstruction

Formal anatomic grading of injury severity, total trauma burden and probability of survival to evaluate whether reported forces and motions did or did not cause the claimed injuries.

Biomechanical Causation Analysis

Laser Scanning

Create high-resolution 3D records of scenes, vehicles, and environments for measurement, reconstruction, and demonstration.

Measure surface conditions and slip resistance to assess fall risk and the plausibility of claimed mechanisms.

Friction Testing

Human Fall Modeling

Simulate and evaluate body motion during falls to assess mechanism, loading, and injury potential.

Explain scientifically grounded opinions in language and visuals that can withstand challenge and help judges and juries understand the evidence.

Deposition and Trial Testimony

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  • “Thank you, on behalf of the family and myself, for your guidance and aid in my preparations for trial and for your impeccable presentation and expert testimony. Your meticulous, straightforward explanation of the unexplainable was vital to our efforts.”

    — Plaintiff Attorney

  • “The ABSOLUTE BEST with whom I have worked in 30 years. Dr. Hayes is superbly qualified and talks right on the same level with a jury.”

    — Defense Attorney

  • “I hope I can impress upon Toby how good Erik is…It's not just that Erik is smart and personable and calm, but he affirmatively called me to make sure we were on track… He was driving his train, which kept the administration pressure off of me. Erik was critical to our success.”

    — Plaintiff’s Attorney

  • “Dr. Hayes impressed the court as an expert witness whose testimony was offered with a view toward assisting the court in understanding technical information in a neutral and unbiased manner. He was a very credible witness.”

    — Judge, United States District Court

  • “Dr. Hayes was instrumental in taking a case in which a jury returned a verdict of $832,000, to a verdict on retrial of $640! I wish we had used him in the first trial as the jury loved him. I have learned my lesson and involve his team in my most difficult cases.”

    — Defense Attorney

  • “A few jurors spoke with me after the [Defense] verdict was read…a HUGE part of their decision was based on [Erik Power’s] testimony. They found him very credible [and] knowledgeable.”

    — Defense Attorney

  • “Erik did an outstanding job [at a jury trial in 2007]. He was extremely well prepared [and] his testimony and presentations were excellent…[S]everal of the jurors approached me after returning a nearly immediate unanimous defense verdict. [A] juror explained that Mr. Power was the best [of our excellent experts]. He was surprised to hear that this was the first time Mr. Power had ever testified in a trial. ”

    — Defense Attorney

  • “All of the jurors told us they were most impressed with [Dr. Hayes’s] explanation of the medical causation issue…no one had ‘compared the impact from the incident to the impacts experienced in the ordinary activities of daily living’…They clearly felt [Dr. Hayes’s] explanation was the most persuasive evidence they had in 3 ½ weeks of trial and their short deliberation supports it.”

    — Defense Attorney, after speaking with jurors following a Defense Verdict

  • “As a lawyer in…who has retained Toby let me tell you this, he is the BEST OF THE BEST in the business. Highest qualified. Most thorough. Best testifier. Incredibly “normal” on the stand and in person. And super likable to a jury. I remain the biggest fan of this man and his company! Truly second to no one I’ve ever seen in this business in my 33 years trying cases.”

    — Plaintiff’s Attorney

  • Erik is really an excellent engineer and a very fine expert witness.

    — Plaintiff’s Attorney

BUILT FOR ATTORNEYS HANDLING COMPLEX INJURY CASES

Technical Insight.
Legal Focus.

Communication Counsel Can Use

Technical findings organized for case strategy, mediation, deposition, and courtroom presentation.

Practical Case Evaluation

Early insight into causation, injury consistency, and the technical strengths and weaknesses that may shape case direction.

Trial-Ready Support

Coordinated support through expert review, reports, depositions, demonstratives, and testimony.

From first discussion through deposition and trial, the firm keeps scope, timing, and technical priorities aligned with the case.

Frequently Asked Questions

Still have questions? Take a look at the FAQ or reach out anytime.

  • We offer a range of solutions designed to meet your needs—whether you're just getting started or scaling something bigger. Everything is tailored to help you move forward with clarity and confidence.

  • Getting started is simple. Reach out through our contact form or schedule a call—we’ll walk you through the next steps and answer any questions along the way.

  • We combine a thoughtful, human-centered approach with clear communication and reliable results. It’s not just what we do—it’s how we do it that sets us apart.

  • You can reach us anytime via our contact page or email. We aim to respond quickly—usually within one business day.

  • We offer flexible pricing based on project type and complexity. After an initial conversation, we’ll provide a transparent quote with no hidden costs.

CLIENT SUPPORT FROM RETENTION THROUGH RESOLUTION

Bring the Evidence Into Focus

When a matter turns on mechanism, causation, or the relationship between forces and injury, Hayes + Associates provides scientifically grounded analysis from preliminary evaluation through deposition and trial.

Submit the form with relevant details, and the H+A team will respond promptly. You may also contact us at +1 (541) 754-9645 or inquiry@hayesassoc.com.