SWEEPING POSITION
A solid sweeping position is the foundation of effective and efficient sweeping. The position should contribute towards high vertical force production, and allow for high sweeping velocity. In addition, the position should be sustainable over the course of a game, ensuring later, potentially crucial, stone trajectories can still be altered through sweeping.
So, what does a great sweeping position look like, and how can you implement changes to improve your own performance?
grip
First, you must consider your hand and arm positioning to best support effective and efficient sweeping:
Upper hand just below chest level, with arm at roughly 90°.
Lower hand at a position where there is a slight bend in the lower arm.
This position will allow for the recruitment of the pectorals, which are a large group of muscles in the chest. The recruitment of greater muscle mass leads to greater contractile forces. This should translate into high vertical forces and high sweeping power production.
Joint angles have an impact upon ability to produce torque [rotational force]. It has been suggested that peak torque at the shoulder is produced in a neutral position, with the upper arm in line with the torso [Walmsley and Szybbo, 1987]. At the elbow, peak torque in extension has been shown to occur between 80° [Osternig et al., 1977] and 100° [Singh and Karpovich, 1966].
Therefore, to produce high contractile forces and power, the sweeping position should aim to have the upper arm in line with the torso and roughly a 90° bend in the elbow to the forearm. Deviating too far from this position may be at the detriment of power production and sweeping effectiveness.
If an athlete sweeps with their hands too far apart, their torso naturally rotates. This causes asymmetric loading across their upper body, overloading the lower arm shoulder, and failing to effectively distribute force across multiple muscle groups. You would also not be employing the large pectoral muscles to as high of a degree. Higher loads through smaller muscles will be less sustainable through repeated sweeping exertions, making this non-optimal position less efficient. The suggested sweeping position spreads load more evenly through the pushing muscles on both sides of the body.
Think of holding a plank position compared to a side plank position. The standard plank position is easier to maintain for longer, since you are utilising larger muscle groups, including the pectorals, deltoids, and abdominals. In contrast, a side plank cannot be held for as long with its recruitment of fewer, smaller muscles, including the deltoids and the obliques. The same is true in the sweeping position.
stability
To fully understand stability for sweeping, there several key definitions to recognise:
Centre of gravity = Point in the middle of an object where gravity appears to act. This point changes location with movement. When standing, the centre of gravity exists roughly behind the belly button.
Line of gravity = Line descending vertically from the centre of gravity.
Base of support = Area formed when you connect each point of contact with the ground.
Balance = Line of gravity falls within base of support. If an athlete is balanced, they are not falling.
Stability = Resistance to disruptive forces, allowing an athlete to remain balanced.
Greater stability means an athlete can remain balanced with lower energy expenditure. Instability challenges balance and must be compensated for through contraction of stabilising muscles. Stable sweeping employs greater biomechanical stability, with less unnecessary movements to maintain balance, allowing for the position to be maintained with reduced physiological demands.
For the same reasons as noted above, instability can be beneficial in training. Inducing unstable conditions during resistance training has been suggested to increase muscle activation and stability [Behm and Colado, 2013].
Increased stability also reduces the risk of falling and subsequent injury, since greater disturbing forces are required to disrupt balance. This can increase confidence, allowing a sweeper to push themselves harder with less fear of falling.
Curling athletes can increase their stability by:
Widening their base of support.
Lowering their centre of gravity.
When sweeping, the base of support is the area formed when you connect your feet and the broom-head. Increasing the separation between your feet is a simple way to enlarge this area. Lowering your centre of gravity can be achieved by pushing your hips forward, with a slight bend in the knees. These changes result in improved stability, since greater forces are required to disrupt balance.
body weight
A forward hip shift is crucial to best utilise body weight whilst sweeping to maximise vertical forces. This hip shift causes an athlete’s line of gravity to be shifted forwards, towards the broom-head and away from their feet. Therefore, a greater proportion of the athlete’s weight is placed through the broom and relieved from their feet.
The result is a baseline vertical force that can be maintained through isometric contractions [no change in muscle length], without the need for arm movement. This force can be maintained fairly consistently, with limited fluctuations in output across sweeping phases. The technique described can be referred to as ‘leaning’ or ‘hard/heavy cleaning’.
Leaning is being used by many competitive sweepers to reduce energy expenditure, whilst maintaining a level of sweeping effectiveness upon stone trajectory. This is because it does not require explosive, powerful isotonic contractions [change in muscle length] of the upper body, as with typical sweeping. However, this has not yet been tested in research conditions. Doing so would give clarity as to the importance of this method, and when it may be of highest value to curlers.
position development
Video analysis can be incredibly beneficial when practicing the sweeping position, allowing analysis of your grip, stability, and body weight utilisation. For example, taking single frames and marking the centre of gravity and line of gravity can be used to calculate how much vertical force is being placed through the broom-head.
An extremely simple method of gaining immediate feedback on your position is to use a bathroom scale. Hold a static position and observe the effects of shifting your hips forwards and backwards. You should be able to see the weight reading increase as the hips are shifted towards the broom-head. This can build familiarity with what a good sweeping position should feel like, and can later be transferred to the ice.
summary
Grip:
Aim to recruit large muscle groups and distribute load evenly.
Upper hand just below chest with arm at roughly 90° [upper arm in line with torso].
Lower hand at a position where there is a slight bend in the lower arm.
Stability:
Stability is impacted by the base of support and relative position of an athlete’s centre of gravity.
To improve stability, increase separation between feet, shift hips forward, and softly bend the knees.
Body weight:
Shift hips forward to increase proportion of body weight through the broom.
Creates maintainable baseline vertical force in isometric position, before moving arms through sweeping cycle.
Position development:
Video analysis can be used to identify areas for improvement and calculate forces.
Use bathroom scales to observe vertical force through broom-head as position is altered.
further thoughts
It is important to note that an individual’s optimal sweeping position will be a sustainable one. Curlers must be able to maintain their sweeping over long games and competitions, so short-term sweeping effectiveness may need to be sacrificed to prioritise efficiency.
This individuality can arise due to physiological differences, allowing some curlers to maintain a more ‘aggressive’ sweeping position for longer. This can of course be improved through specific training, designed to support a strong sweeping position.
Finally, it would be amazing to see new research investigating what determines an optimal sweeping position. This research could investigate variables such as muscle activation, power output, and fatigue during a variety of sweeping tests, with different sweeping techniques. This would better inform coaches and players on how to create sweep better and craft improved training programmes. Until then, objective sweeping testing should be used as much as possible to analyse individual performance, and implement interventions accordingly.
references
Behm, D.G. & Colado, J.C. [2013] Instability resistance training across the exercise continuum. Sports health, 5(6), 500–503. link
Osternig, L.R., Bates, B.T. & James, S.T. [1977] Isokinetic and isometric torque force relationships. Archives of physical medicine and rehabilitation, 58[6], 254–257.
Singh, M. & Karpovich, P.V. [1966] Isotonic and isometric forces of forearm flexors and extensors. Journal of applied physiology, 21[4], 1435–1437. link
Walmsley, R.P. & Szybbo, C. [1987] A comparative study of the torque generated by the shoulder internal and external rotator muscles in different positions and at varying speeds. The Journal of orthopaedic and sports physical therapy, 9[6], 217–222. link
