SWEEPING TECHNIQUE: EFFECTIVENESS AND EFFICIENCY

Strong sweeping is a crucial component of successful curling teams. So, what does a solid sweeping technique look like and what should it aim to achieve?

There are 2 key metrics which determine sweeping performance:

Effectiveness
Efficiency

When developing each aspect of a sweeping technique, these 2 components should be addressed. Therefore, we should explore their importance, measurement, and practical implications.

effectiveness

Effectiveness is the ability to sweep to impact stone trajectory when needed. More effective sweeping will be more powerful. This means that an athlete can produce high vertical forces and high sweeping frequency [Marmo et al., 2006].

Effective sweeping will increase an athlete’s impact on stone trajectory. This will then increase the likelihood of improving shot outcomes, through optimising the dynamics of the delivered stone.

Physiologically speaking, sweeping effectiveness can be measured through determining sweeping velocity/frequency, sweeping force, and sweeping power at a given moment. It is important to note that there are alternative factors which affect sweeping effectiveness, other than pure physiological performance. Examples of these factors include situational awareness, sweeping angle, and reaction times.

As curlers fatigue, their sweeping power output will reduce. Therefore, their sweeping effectiveness decreases. This can become problematic over extended periods if they do not sweep with efficiency.

efficiency

Efficiency refers to the maintenance of effectiveness whilst reducing physiological demands. The definition of mechanical efficiency is the ratio of power output to energy expenditure [McBride and Snyder, 2012]. This describes the performance returns an athlete will receive for a given effort exerted.

Higher efficiency means an athlete can perform for longer before experiencing fatigue, are able to maintain higher levels of sweeping performance, and will experience reduced injury risk. In curling, this is especially important as games, events, and seasons can be long.

Sweeping efficiency can be measured by comparing sweeping power to energy expenditure. Ideally, sweeping power would be very high and energy expenditure very low. The gold standard of energy expenditure measurement is indirect calorimetry, via gas analysis [Ndahimana and Kim, 2017]. I am yet to see curling research incorporate this method. An investigation of this nature may help us in developing an optimal sweeping technique, through understanding how to maximise efficiency.

what determines effectiveness and efficiency?

There are a variety of factors which determine effectiveness and efficiency. These factors include:

Technique [Elphinston, 2008].
Muscle fibre composition [Methenitis et al., 2019].
Motor unit [muscle] recruitment [Del Vecchio et al., 2019].
Range of motion and stability [Elphinston, 2008].
Stretch shortening cycle [Turner and Jeffreys, 2010].

Optimising these variables will contribute towards powerful movements and minimal wasted energy. Unfortunately, these factors have not been investigated in scientific research in curling. Improved understanding of these variables can further inform technique and training, specific to sweeping.

sweeping technique

Technique is the neuromuscular ability to sequence contractions and movements to perform a specific sporting skill [Elphinston, 2008]. The sweeping technique requires the coordination of multiple movements to maintain effectiveness and efficiency.

When developing each aspect of the sweeping technique, effectiveness and efficiency should be considered as goals to achieve.

summary

Effectiveness:

Effectiveness = The ability to impact stone trajectory through sweeping.
Higher sweeping power output leads to greater effectiveness.
Reduces with fatigue.

Efficiency:

Mechanical efficiency = Ratio of power output to energy expenditure [minimised energy wastage].
Higher efficiency means a curler can maintain sweeping effectiveness for longer.

Determinants of effectiveness and efficiency:

Technique.
Muscle fibre composition.
Motor unit [muscle] recruitment.
Range of motion and stability.
Stretch shortening cycle.

Sweeping technique:

Effectiveness and efficiency should be the goals when developing sweeping technique.
Improvements in both leads to greater performance.

further thoughts

Observing elite athletes, it is clear that they are effective sweepers, hence their high performance level. In modern curling, it is unlikely that front end players will be successful without this valuable asset.

However, they may not always be as efficient as they could be. We can see some curlers sweeping with techniques which likely aren’t sustainable to most people, and may increase injury risk. A lack of efficiency can be compensated for through other means, such as outstanding physiology, allowing athletes to maintain powerful sweeping despite technical limitations. This has been observed in other sporting examples [Elphinston, 2008].

Research that supported sweeping technique development, through better understanding efficient movement in this specific context, would be welcome. This would be useful to many curlers, informing training, enhancing sweeping performance, and reducing injury risk.

references

Del Vecchio, A., Negro, F., Holobar, A., Casolo, A., Folland, J.P., Felici, F. & Farina, D. [2019] You are as fast as your motor neurons: speed of recruitment and maximal discharge of motor neurons determine the maximal rate of force development in humans. The Journal of physiology, 597[9], 2445–2456. link
Elphinston, J. [2008] Stability, Sport, and Performance Movement: Great Technique Without Injury.
Marmo, B.A., Farrow, I.S., Buckingham, M.P. & Blackford, J.R. [2006] Frictional heat generated by sweeping in curling and its effect on ice friction, Proceedings of the Institution of Mechanical Engineers. Part L, Journal of materials, design and applications, 220[4], 189-197. link
McBride, J.M. & Snyder, J.G. [2012] Mechanical efficiency and force–time curve variation during repetitive jumping in trained and untrained jumpers. European journal of applied physiology, 112[10], 3469–3477. link
Methenitis, S., Spengos, K., Zaras, N., Stasinaki, A.N., Papadimas, G., Karampatsos, G., Arnaoutis, G. & Terzis, G. (2019) Fiber Type Composition and Rate of Force Development in Endurance- and Resistance-Trained Individuals. Journal of strength and conditioning research, 33[9], 2388–2397. link
Ndahimana, D. & Kim, E.K. [2017] Measurement Methods for Physical Activity and Energy Expenditure: a Review. Clinical nutrition research, 6[2], 68–80. link
Turner, A.N. & Jeffreys, I [2010] The Stretch-Shortening Cycle: Proposed Mechanisms and Methods for Enhancement. Strength and Conditioning Journal, 32[4], 87-99. link