KOP

A Redundant Absolute Measurement?

Following on from the last issue’s look into the efficacy of the KOP method, Scott Cornish takes a swing at it from a physio perspective

Like many aspects of fitting to measurements, we have come to understand that we can’t fit everyone nicely into prescribed boxes due to individuals’ variances in movement, anatomy, injury, pain, asymmetry, medical conditions, preexisting notions about what a good fit should look like/be. A non-exhaustive list of elements to consider. This is not taking into account riders racing under UCI regulations.

During my physiotherapy education, we were taught that humans should have a certain posture, move in a certain way, that asymmetry IS the cause of an individual’s pain and should be corrected. Amongst numerous other aspects within physiotherapy, understanding has since developed and this notion of prescribing the same measurements to every rider just isn’t valid.

There are so many more factors to ascertaining an appropriate KOP position than a simple, single measurement. It’s a combination of factors determined from appropriate subjective and objective assessments, on the bike of course, but more essentially off the bike that. Aspects a motion capture machine won’t tell us either. As well as the standard subjective and objective prefit assessments, additional ones should be added specific to the reasons behind the rider seeking a fit.

Age is a factor to consider (but not be taken in isolation) as our tissues unfortunately degenerate. Disc height and elastin levels are elements that can be affected, so where a rider may demonstrate a high range of flexibility, but they may no longer be able to sustain that range for a long period of time. It’s not just about muscular flexibility though, assessing neural mobility is key too; to add into the overall picture and it’s knowing how to differentiate between the two.

Incidence of LBP or medical conditions, such as scoliosis or disc pathologies are a big factor too. A more forward position is going to off-load these structures in combination with a more ‘neutral’ lower back posture. Simply making the front end higher to open the closed hip angle won’t necessarily change the forces going through the lower back area and it can encourage a more slumped seated posture, especially when fatigue sets in. A rider’s positional proprioception being a key element.

KOP as a measurement is certainly redundant for the modern MTB with their more forward geometry. The numbers deliberately put riders in a more forward position over the pedals to balance out the slacker geometry of the headtube and for more efficient climbing over steeper terrain. It would completely throw out the desired handling and balance of the modern MTB if you try to fit a rider to the standard KOP measurement. I’ve tried and it’s awful! Without the weight on the front end, both descending and climbing ability is hugely compromised. Some modern gravel bikes are also adopting this longer and slacker geometry philosophy.

The standard KOP measurement is simply a starting point and it’s through a thorough subjective and objective (critically off the bike) assessment that will determine the eventual position. There are too many variances to assume that a rider will fit into the mould of averages. For a more precise and efficient fit, we need to understand the rider in front of us as an individual, both physically as well as psychologically.