Ski Collision

Accident Reconstruction Case Study

In this ski collision accident reconstruction case study, a young experienced skier decided to attempt a 360 degree, blind jump over a berm. This resulted in a collision between himself and another skier. The other skier suffered a neck and shoulder injury, and the skier attempting the jump suffered an ankle injury. Kineticorp was hired by Jim Gigax to investigate and gather the physical evidence to determine where the contact occurred between the two skiers and develop a reconstruction of the accident.

Video Transcription

James Gigax: This young man had jumped. He had just done a 360 without looking. He was just flying. Wiped out this gentleman, and then he came up and he was just screaming at him, and the person who had wiped him out had verbally abused him in the presence of his wife. His life had been fundamentally altered to the negative.  My client was a 63-year-old dentist. A very successful dentist. This incident broke his neck, and he also had his shoulder ruined. You could have your shoulder re-constructed, but it’s never going to be the same.

Tomas Owens: Some of the pieces of information that we had from the beginning, were injury locations. So, we know that one person was injured in a specific part of their body, and we have an idea of where that contact may have happened. In this case, we had one gentleman who had a broken shoulder, and the other one had injuries to his ankle. So, again, two puzzle pieces, I know they have to fit together somehow, most likely. And all the other evidence led to the fact that this was sort of the contact point of what their impact configuration might’ve been.  So, we have to start with, what physical evidence do we have? Do we have any video reference? Do we have photographs from the time of? And pretty often, that’s our biggest resource is the photographs that were taken at the time of the accident.

Toby Terpstra: So, one of the things we didn’t know in this case, is where exactly he came to rest. Fortunately, we had a couple of photographs. Trying to locate where somebody came to rest in the middle of a ski run, there’s not a whole lot of features, not a whole lot of landmarks in the middle. You’d be lucky to find something to use as a reference, and really there’s nothing other than a berm up above, and then the trees that are in the distance in both of these photographs.

Tomas Owens: So, in this case, kind of the logical progression that we used was starting with videos and photos, and being able to use photogrammetry to match up specifically where certain photos were taken, and matching that up against the evidence that we took ourself, being the 3D scan data.  So, the fact that we were fortunate enough to visit the actual site, gives us a perfect one-to-one relationship of the digital world to the actual scene itself.

Toby Terpstra: We actually took a radar gun out there too, and measured other people as they were coming down the slope, just to get a feeling for what the general traffic flow might be like. So, this guy’s following his friends down in a lot of his YouTube videos. I mean, when you get a feeling for their style of skiing, it’s useful to be able to understand how they’re moving as they do these jumps, and so it becomes a great reference.

James Gigax: We got the clients involved. We had a meeting where we could show this animation to my clients, who are in Tennessee, and it was done to be admissible. And it was a good final product we could get into evidence.

Tomas Owens: My job as the animator is to create the most realistic and honest representation of how this person would have moved from A to B. So again, the foundation gets us these sort of specific hard-coded positions that we need to be in, and then it’s my job to determine the flow of the movement.

Toby Terpstra: There’s a road that cuts through there, and it creates kind of a natural berm that the skier’s using as a jump, and that berm as you’re approaching it, you can’t see over it depending on where you’re at on the slope from left to right, so it is a blind area that he took the jump over, and that visibility’s occluded because of that berm or that road that’s cutting through there.

Tomas Owens: One of the unique challenges that we faced was getting two characters two bipedal representations to interact with each other and have physics take over. The fun of problem solving this was getting to hop to another piece of software that I know would be a solution for this, but integrating that into our current workflow.

James Gigax: You let people who understand physics and are conversant with computer programs that incorporate physics and then in turn that generates numbers, and then the computer software will take these calculations and the data points, and that’s all run together to make it look almost like a real video. Very important for the attorney to put in the time to understand what’s going on. Even though you have to rely on other people for the math, you got to understand how these people did their work in order to be able to explain it to a court so that the work product is admissible.

Toby Terpstra: You don’t want to open yourself up to anything that can be criticized. So we’re using 3D scan data to understand what the slope looks like and what the visibility is as you come over that berm from the roadway. We’re using everybody’s witness testimonies in conjunction with each other to understand how close other parties may have been. As you play through the animation, as you go through that sequence, it is important to understand how fast he was going and how close these other kids were and establishing the conditions at the time of the incident, what he did with his friends going blindly off this jump, was dangerous.

James Gigax: Kineticorp was a key strategic partner for my client and I. They were a key part of the successful outcome of that case.

The Process:

Throughout the case, Forensic Animators Toby Terpstra and Tomas Owens analyzed the witness statements, scanned the scene in order to preform camera matches and also recorded speeds of general ski traffic through the accident scene using a radar gun. Toby Terpstra also skied the accident scene several times to get a better understanding of the rate of speed. In addition, Tomas Owens analyzed the young experienced skiers’ YouTube channel where he had several videos of himself skiing and preforming different maneuvers including 360 degree spins. Taking into account the physical evidence, witness statements, radar gun readings and YouTube videos, our team was able to create several animations from different perspectives, which were grounded in physics.

The Results:

The case resulted in a favorable settlement for the client. More information can be found at our clients’ website,

The Team:

Toby Terpstra, Tomas Owens

Related Case Studies, Content & Research:

Photogrammetry Analysis

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