SCIENCE OF CYCLING: Mastering load – Part 1. How do we analyse loading in cycling?

10.Sep.19 | Bikefit, Physiotherapy

CYCLING Mastering Load is not a hot topic of discussion in journal articles or blog spots, not-withstanding the significant levels of non-traumatic injury or pain suffered by cyclists both recreational and elite (DeBernardo 2012, Clarsen 2010, Dannenberg 1986).

Mastering Load implies a detailed understanding of the features and characteristics which can influence non-traumatic injury.  More recently there has been strong emphasis upon training load and its influence upon injury, from thought leaders such as Tim Gabbett, Yann LeMeur and Michael Drew, but mainly related to rugby, cricket and Australian football.

Historically, injury management practitioners have analysed mechanical components of movement such as kinematics, vertical ground reaction forces and muscle activation to predict and/or explain tissue overload.  Jumping and landing theory gives evidence of the ability to change mechanical loading characteristics during activity, and current concepts in the management of patellofemoral pain syndrome (PFPS) and anterior cruciate ligament (ACL) rupture also have mechanical deficiency and subsequent rehabilitation as key tenets (Hewett 2006).

FACT: We can change mechanical loading AND it is important in injury management.

What about cycling?

The Mastering Load conversation is not quite as evolved in cycling, and is complicated by the nature of cycling, which of course involves a bike.  The emphasis regarding the mechanics of cycling has always been focused upon bike geometry and rider set-up to the bike.  There is little or no discussion of the mechanical ability of the body, as there is in PFPS or ACL injury.

Power production, VO2 max, joint moments, seat height, knee angle, fore-aft seat position are all parameters measured in cycling research, but a recent systematic review of cycling non-traumatic injury  related research (Visentini 2015, in press) found no evidence that these parameters are related to injury.  The emphasis in research has been upon performance.

FACT: Most bike set-up theory is not based upon injury data but performance data.

There is some evidence that excess lumbar flexion is related to lumbar pain (Van Hoof 2012), and that volume in cycling relates to altered nerve conduction (Akuthota 2005, Anderson 1997).  There is softer evidence that excessive dorsiflexion in the pedal stroke as well as knee valgus in the frontal plane could be related to knee pain.

FACT: Body related parameters have a relationship with cycling injury/pain.

compressed

What if?

Taking on board the theory of mechanotransduction being a cellular reaction to mechanical load (Khan and Scott 2009), what if a cyclist suffers a fall and subsequent back pain, which can affect gluteal muscle activation.  At times of peak power the cyclist has been shown to maintain power levels regardless of the activation pattern.  In this case the gluteals may be deficient and the other power group, the quadriceps, need to work 15% harder.  What effect on the articular cartilage matrix of the retropatellar surface with this increase in patella-femoral compression force (PFCF) due to an increase in the quadriceps moment arm (McLean and Blanche 1994).  Isn’t this like a training load error – increasing local loading by 15% as compared to the same session the previous week?

FACT: All non-traumatic pain or injury in cycling is essentially an error in loading which causes a cellular and matrix response.

The clinical reasoning process in cycling injury management requires a knowledge of the cycling body, bike set-up, pedaling mechanics and activation, training load measurement and analysis, and tissue response characteristics.  In essence a “mastery of loading” is required to best manage the cyclist in-clinic.

Want to know more?

Join us at our Science of Cycling course on 26 & 27 October 2019. Email courses@physiosports.com.au for a registration form.

Click below for:
Part 2: Breaking down the cycling kinetic chain
Part 3: Measuring Cycling Training Load