Frans Bosch: Fine-Tuning Motor Control

In the book, “High Performance Training for Sports”, renowned strength coach Frans Bosch outlines his methodology and philosophy, specifically for optimising running performance.

Bosch considers – though not in great depth – the motor control theory behind his coaching practices, to provide insight into why some exercises are effective at improving performance and others are not. Two control systems exist: one fast and unconsciously controlled, and one slow and consciously controlled. Many movements in sport are required to be performed so quickly and with little warning or notice that they can only be executed automatically, and without input from the working memory or executive parts of the brain. This is important when attempting to maximise transfer of training to an athlete’s sport.

 

Specificity and Transfer

Bosch outlines 5 criteria for specific transfer, whereby to enhance transfer and thus sports performance, there must be similarity in the following areas:

  1. Muscle action
  2. Limb motion
  3. Sensory information available
  4. Dominant energy system
  5. Movement result (there is better transfer when there is a clear difference between a successful and unsuccessful movement, e.g. clean > high pull in terms of transfer)

Part vs whole practice

Part practice refers to one or more of the components from the overall movement, whereas whole practice leaves the functional movement intact. Whilst whole practice is best, part practice can be useful. For example, some components of a movement might need work in isolation as they are hard to improve in a competition context. Bosch offers no guidelines for when part practice should be implemented, instead putting this down to the art of coaching.

 

Dynamic systems theory

After debunking hierarchical and schema theory models of motor control, dynamic systems theory is used to make sense of the execution of motor skills. The theory posits that there are stable and unstable components in any movement pattern, namely attractors and fluctuations. Examples of attractors (stable components) during running would be hamstrings working isometrically at optimal length, the extension reflex, and the ‘whip from the hip’ that accompanies correct foot placement to decrease braking force. Fluctuations include knee height and arm action, which vary depending on the environment.

He does offer justification for categorising knee height and arm action as fluctuations, which many coaches likely treat as attractors in their athletes’ training. Arm action can vary greatly without affecting performance, and is used mainly to correct perturbations, while knee height varies depending on running speed and stride frequency. Time would be wasted then, coaching either component at sub maximal speeds.

What’s the importance of separating a skill’s components into attractors and fluctuations? Firstly, it affects what components should be coached. It would be a mistake, Bosch argues, to apply struct rules to the fluctuation components. Instead, self-organisation should be given a chance. Conversely, it is important to learn how to perform the essential attractors correctly.

Attractors become ingrained (or learned) with variation. Varying the exercises used increases the stimulus and thus leads to greater learning. For example, running over uneven surfaces is an intuitive way to gain active ankle extension before ground contact, an important attractor in running. Overall, the quality of the movement is based on the ability to execute its separate components and to effectively adapt it to the environment.

From top to bottom, the wells (attractors) become deeper (more ingrained). The bottom arrangement is indicative of a more efficient and effective movement that can be performed in various environments. (p.120)

Strength training for high speed running

Keeping all of the above in mind, strength training should be highly specific and work on key attractors. For example, a single leg glute-hamstring raise (GHR) where the hamstring isometrically (mostly) contracts to inhibit knee extension and enhance hip extension.

The two most important end position in running are said to be the end position of the extension reflex, and the absence of rotation at toe off. By using these endpoints as the intention or ‘movement result’ of the exercise, transfer can be enhanced (see the 5th specificity criteria). The former can be exercised with SL cleans or step ups, whilst the latter can be worked on with medicine ball runs or OH stick runs, for example. Interestingly, Bosch argues the overload should not be sought in increasingly higher weights, but instead in variability. Whilst specificity is needed to train key components, variation is needed to challenge the athlete to perform the skill in multiple environments, by adjusting the fluctuations appropriately.

Finally, as the contractions of the lower leg occur isometrically during running, there is no point using traditional strength training here, such as calf raises. Instead, depth jumps can be used, whilst attempting to keep short contact time. In fact, the sooner the body is able to produce force when it hits the ground, the fast the athlete will run. It is important to improve rate of force development with such exercises with have a timed goal.

As an aside from myself, whilst Bosch says you can’t overload the calf complex with weight training, I wonder how much maximal isometric contractions could be used here. I have been playing around with max iso’s in the shape of multiple 5-10 second calf raise holds with maximal intent with a back-loaded barbell pushing into squat rack bars, or a bar tied down with a chain. I then follow this up with pogo jumps (straight leg) or, indeed, depth jumps. Whilst the max iso is mostly for increased motor unit recruitment prior to a plyometric exercise, it could also be effective in itself in overloading the calves, albeit without a time restriction like when jumping.

 

The chapter packs in a lot, and I intend to read his latest book on  soon: Strength training: An Integrative Approach

High-Performance Training for Sports is available to buy, too, with lots of other useful and insightful chapters.

Bosch, F. (2014). Fine-tuning motor control. In: D. Joyce and D. Lewindon, ed., High-Performance Training for Sports. Human Kinetics, pp.113-126.

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