My life changing injury was a step off a curb. I was carrying a large bag of trash held out in front of me in my left hand. My right hand had a wrist splint for a carpal tunnel flare up. I walked across a sidewalk that had a slope to it. The garbage bag blocked my view.

I thought it was a handicap ramp by the slope. I was leaning back with my back arched to counter balance the load in front of me. When I stepped off the curb, I landed with my left knee locked. I injured my hip, pelvis, lower back, left shoulder, neck and base of my skull. It also left me with a "bell rung" feeling. There was no other pain right away. I checked out of my job.

When I tried to put my seatbelt on to drive home, I realized how bad I had injured myself. I reported the injury the next morning. The employer treated the physical injuries but refused to acknowledge the neurological injury, even after a neuro-psychological assessment that showed slowed processing (bottom 10%) and auditory and visual immediate and short term memory in the bottom 5 to 12%.

The doctor said that such a mild fall/step could not have caused a head injury and my Work Comp got denied for the neurological/cognitive component. He denied that there was enough force to cause an injury.

I did the research. A fall of 8 inches onto a hard surface with a one eighth inch deflection (compression of my boot sole and/or skeletal structure) can result in a 62 G impact. If the deflection was one quarter inch, the G force would be 31 G's.

This was concussion number 13 for me. I had one very severe concussion at 10 years old. Three moderate concussions and about nine mild concussions, including the last at age 46.

I still have a persistent problem with the injury at the point where the shoulder is supported by the vertebra along with the post concussion symptoms.

I can get a concussion from turning my head to the side and back quickly and from a ride in the car down a rough road. I have learned to turn my head slowly or from the shoulders. I also know to sit with my back away from the seat back to lessen the impact forces generated by a rough road. I snow ski with a shoulders hunched forward position to lessen the forces transmitted to my head.

With the upper spine curved forward, the back has a very good impact absorbing ability. When it is straight up or worse, arched back, it has very little impact absorbing ability. You can easily see the difference by sitting in a chair with your back arched. There is no vertical movement of the head.

An injury I believe I have but is undiagnosed is some sort of contusion to the left occipital condyle. It frequently get inflamed and stiff.

All of my persistent problems are from a few milliseconds of 30 to 60 G's of vertical force to my head. I would not believe it if I did not live it 24/7.

If it was not for the confirmation of two neuro-psych assessments, I would still be wondering whether this was just an imagined set of symptoms.