My background is a chiropractor and not a pro bike fitter. However, I have an interesting case that came into my office regarding bike fitting. I am actually thinking of writing this up in a professional journal. In the spirit of Xantusia/FIST and all the bike fitting posts on this forum I’ve decided to put this up to you fellow forum members as a quiz and ask for any thoughts and possible solutions. At the end of today I’ll post what worked as a solution.
We are dealing with a thirty-five yr. old female AG triathlete who is starting her third season in the sport, participating in sprint events. She had a competitive cross country running background at college and has ben a recreational swimmer and cyclist. She is unique in that she has quite a severe scoliosis which at age 12 required the permanent fitting of a Harrington rod by an orthopaedic surgeon. A scoliosis is an abnormal S shaped curvature of the spine. The sugically implated Harrington rod is designed to prevent this form getting any worse.
Her biomechanics are unique. With the spine being S shaped rather than strait when viewed from the front, she is an estimated two to three inches shorter than she would be,increases her proportionate leg to torso ratio compared to normal. The Harrington rod runs from the third thoracic vertebra to the second lumbar verterbra, preventing normal movement in this area of the spine. My examination demonstrated quite limited gross spinal movement with rotation and extension, but amazingly, she had excellent flexion (bending forward to touch toes). I concluded that most of this forward motion was because of above average flexibility in her hip joints and hamstrings, possibly developed as compensatory mechanism to the lack of spinal mobility. X-rays revealed moderate disc degeneration in the upper thoracic and lower lumbar spine in the areas where the Harrington rod is attached. This early disc thinning is a common finding with Harrington rods due to the biomechanical forces in this area.
Because of the Harrington rod, she has a sightly noticeable different walking and running gait and when swimming is unable to rotate her body as in the ideal swim stroke. Despite a seemingly obvious handicap, last year in the six sprint tris she ran, two 1st’s, a 2nd, two 3rd’s, and a fifth were obtained in her age group.
She purchased a Giant OCR fitted with Profile Jammer GT aero bars. This was set up in the classical road position by the LBS without paying attention to her unique situation. She developed neck, low back and knee pain while riding. It was then she brought the bike to me for a fitting. She has also recently purchased a Cervelo P2K which was also set up for her with this scoliosis/Harrington rod condition in mind.
So I’m throwing this out to you fellow forum members for suggestion before revealing how a solution was found. Tom, Dan, Gerard, Endurosport and all you others at Xantusia, let’s hear what your approach might be. Anyone else as well. I’ll post what we did later.