Below is a picture taken from an article over on Pinkbike featuring Neko Mulally and Erin Huck; showing very clearer the difference “environment” makes to skill acquisition!
The XC bike given it’s seat height and overall geometry has dictated that Erin can’t drop her heels or more accurately cannot lower her Centre of Mass (COM) via ankle dorsi-flexion and instead achieves an overall lowering of mass over her base of support by flexing the hips and getting into a very low posture that is arguably extremely inefficient!
Neko on the other hand due to his bike and how he acquired the skill of posture over the years demonstrates that “archetype” Gravity posture, ankles dorsi-flexed, knees in slight flexion, hip angle “open” at about 30 degrees of flexion. Elbow and shoulder jut behind bars etc…
Now, yes, Neko is on flat ground and Erin traveling on a slight downward slope that is possibly steepening and yes we avoid extrapolating to much from one pic. But extreme hip flexion while traveling downhill to help lower COM is not ideal.
It means hips and knee joints are at sup-optimal angles to allow the muscles acting on those joints to operate at their preferred length and thus act most efficient and make use of not just he contractile portion of muscle tissue but also the whole MTU (muscle tendon unit) and the inherent efficiency of elastic strength!
The final two pieces of the puzzle are the joints furthest from each other but both performing important functions and both having interesting effects proximally (towards centre of body)…the cervical spine (neck) and cleat position and it’s relation ship in distance to the Talus bone in the ankle.
Extreme hip flexion for whatever reason (usually COM lowering) results in the necessity of extreme neck extension to see where you are going! This arguably and supported in some research has a knock on effect on the autonomic nervous system (ANS) and leads to a further reduction in para-sympathetic tone and thus possibly more unnecessary stress, when the act of descending should be pretty chilled! Some riders like Nino Schurter display pretty extreme hip flexion when descending as that’s what the constraints of the bike dictate but still manage to keep a pretty relaxed neck position and overall excellent control.
Cleat distance to talus bone is not really understood and it’s only something I’ve recently thought about, but the Talus is considered the centre of your Base of support as a bi-pedal human, and arguably the further the cleat is away from that point the less stable the the ankle joint will be perceived by the brain, CNS and possibly less effective natural or learned spinal reflexes will be thus again leading to more “tight” the posture and the less stable the fluctuators of technique needed to make fast corrections in posture, directions and weight shift will be!
No exact science here – and there never will be when it comes to technique, skill and their acquisition!
Skill is about an end result. The intention of movement and reaching the end place or goal having expended the minimum of energy. Understanding that riding an MTB is a complex taste within a complex system and that the constraints of the task, organism and environment are very, very central to how you learn or perfect something new is what this is all about!
Bike set-up, terrain, dirt moisture, ambient temperature, tyres, muscular or central fatigue among 100000 other things affect your ability to reach that end goal.
So practice really does make perfect; but perfect practice does nothing to help you learn and adapt, So while Erin’s technique is extreme and sub-optimal in a global sense it is the technique she has adopted given the constraints of the environment (bike and terrain) she learned it in. If that technique is consistently applied in a huge variety of situations and terrains then it’s key parts will become stable enough for it to be successful as-long as those stable “parts” consistently allow her to achieve her end goal or intention!
Neko? We’ll I think Neko will be just fine…. 😉
Original article here – http://www.pinkbike.com/news/brevard-ride-camp-with-neko-mulally-and-erin-huck.html