The sprint kayaking core conundrum 

When it comes to using the core for sprint kayaking, the athlete needs to solve contrasting challenges – how to be: 

Strong + Stiff

whilst  being

Flexible + Adaptable 

During the water phase the athlete needs to the core to be stiff and strong enough to generate force and withstand the pressure on the blade without the body (frame) collapsing in one or more planes, but at the same time the core needs to remain flexible enough to allow the body to; fully rotate, adapt to unpredictable water and boat movement, and help control the changing forces on the blade at the exit. 

During the air phase, the athlete then needs to be able to ‘freeze’ the trunk and quickly dissociate arms (and scapula) from the core in order to move the arms quickly and efficiently (and give the body time to ‘rest’). 

If the sprint athlete wants to paddle both fast and efficiently, they need to be able to balance these opposing systems without letting one system take over. For this, it’s vital the athlete develops a high level of body awareness, and has stabilisers and movers which are not only strong, but well-balanced and functioning correctly (doing the right job at the right time). 

Core Imbalances and dysfunction on the water

In Part 4 of this series, we looked at how stabiliser/mover imbalances and dysfunction generally increase energy consumption and impair movement. So let’s now look at what specifically happens on the water when things get out of whack, and the movers become overly dominant.

In addition to increasing energy consumption, stabiliser/mover imbalances and dysfunction can affect: 

  • rotation 
  • water ‘feel’ 
  • balance 
  • breathing 
  • air phase efficiency 
  • general posture 
  • pelvis positioning 
  • force distribution  
  • injury risk 

In other words, just about everything.. so let’s tackle each one individually.

Rotation  

If the movers of the core are being used in a more static way to help stabilise the spine, they will be prevented from lengthening and contracting fully, which can restrict rotation. It can also reduce the amount of torque the athlete is able to produce and use effectively (as torque relies on the muscles lengthening and contracting).  

Water ‘feel’ 

If the athlete has a local issue with stabilising the body with the movers, they may use this stabilisation strategy for the entire body. In this case, it makes it difficult/impossible to properly dissociate (isolate) the arms and shoulders from the core. These athletes appear robotic and stiff on the water and will ‘kill’ the water with their whole body, rather than ‘feeling’ it with their hands and arms (I call them the Tin Man/Woman).  

If the athlete is strong, powerful, and fit enough to be able to generate speed like this, their relative energy consumption and heart rate will likely be very high (it’s also likely they will have an abnormally high tolerance to suffering – they may even enjoy it…).  

If an experienced athlete has a core stabilisation pattern that uses the movers, but they are not strong and/or fit enough to be able to sustain Tin Man/Woman paddling, then they will often become soft and floppy like a Rag Doll when they start to get tired. Rather than being able to feel and support pressure on the blade throughout the water phase, they will fall through it (slip). (With juniors and beginners this may happen due to a general lack of strength and weak frame, rather than stabiliser/mover dysfunction).

Air phase efficiency 

If the athlete has been artificially locking their scapulas (shoulder blades) onto the trunk with the movers (rather than stabilising them with the shoulder stabilisers) during the water phase, it is highly probable they will struggle to dissociate (isolate) the arms from the core during the air phase, instead using the entire body to move the arms and wasting energy. If they continue to lock the scapular in a fixed position with the movers during the air phase, they also place the shoulder at a much higher risk of injury during as the head of the humerus will be blocked from moving freely in/with the shoulder joint.   

Balance 

Even though balancing the boat involves the whole body, strong core stabilisers are essential. If the core movers take over this role (or become overly involved), the body can become too rigid to be able to adapt to the water. More experienced athletes will find a biomechanically and technically inefficient way to survive this, however inexperienced athletes will generally take a swim instead.  

Breathing 

If the core stabilisers are weak and the athlete has allowed themselves to sit in a slumped position, the diaphragm and other abdominals will be compressed. This makes deep breathing more difficult.

If the stabilisers are weak and the athlete is trying to sit tall (or stabilise) using the movers which sit external to the rib cage, the expansion of the rib cage may be severely inhibited, also restricting breathing.  

Posture  

From the outside an athlete may appear to have relatively ‘good’ posture in the boat. However if the deep stabilisers are weak or switched off, the athlete will most likely be ‘holding’ themselves up using the external movers, rather than being ‘lifted’ up by the internal stabilisers. This athlete may feel like they need to squeeze their abs, tense their upper back, or raise their pecs to sit tall.  

Using movers to support posture can be extremely tiring, especially once the movers have also been doing their real job (moving the body) for a while. These athletes will often start a session with a seemingly ‘good’/upright posture, but start collapsing downwards as soon as they get tired.   

This is why ‘Sit tall’ – isn’t always a useful cue unless we first examine what was preventing the athlete from sitting tall in the first place. If the primary stabilisers are strong and functioning optimally and the pelvis is well positioned, then sitting tall (without load) should feel effortless.  

Note – Asking an athlete who hasn’t learnt to support posture using the deep core stabilisers to ‘Sit Tall’ when they are tired and have overworked their movers, tends to be a recipe for all-round frustration! 

Pelvis positioning 

Paddling with an excessively tilted pelvis (posterior pelvic tilt) shortens/compresses the deep anterior core muscles to the point where they can struggle to support either good posture or the stroke. This position also has a tendency to break the connection (transfer of energy) between the legs and trunk (so even if the athlete’s legs are moving up and down, the athlete won’t necessarily be generating any useful power from them – although they may be generating large amounts of backwards inertia). 

Posterior pelvic tilt (+ backwards rotation) = core disengaged
Neutral spine and pelvis (forward rotation) = core engaged
Force Distribution

Being able to balance the pressure on the blade by distributing the forces throughout the body, is vital for avoiding excessive boat roll, sideways leaning*, collapsing of the spine in one or more planes, and energy leaking. It is also essential for maintaining true grip throughout the whole of the water phase (avoiding slip).

*If the athlete can’t balance the force on the blade internally, they will have to lean to the side – away from the blade to balance the boat – (losing power in the process).

This distribution of force is primarily the job of the core stabilisers (combined with good integration of the legs with the core). However as we saw in Part 4, if the movers are overly involved in stabilising, the stabilisers become less receptive, and their ability to distribute forces becomes impaired. 

Injury risk 

Aside from supporting efficient technique, the core stabilisers also play a very important role in helping distribute force/load throughout the body to avoid excessive stress building up in one specific body part.  

When the movers take over the stabilising role, they are not nearly as good at distributing these forces, in turn leading to a higher risk of injury. (This is one of the reasons why I believe that we as kayak coaches have a responsibility to help build well-balanced athletes, not just focus on sport specific exercises we think will help make them great paddlers).

 

Technical profile of athletes with core dysfunction

The core stabilisers can be weak with a wide range of athletes, and we could sit around all day and debate the chicken or the egg;  

Have the deep core stabilisers become weak because of the athlete’s paddling technique, a gym program which focuses primarily on strengthening the global movers, and poor sitting posture in daily life (with too many hours on the computer/phone)?  

or 

Did weak core stabilisers and poor core integration cause the athlete to develop a certain way of paddling in the first place?

The answer isn’t really relevant because weak core stabilisers and/or poor integration, are a problem for both the health of the athlete and technical efficiency regardless..  

Whilst there isn’t a specific athlete profile for weak stabilisers/strong movers, the deep core stabilisers are often chronically weak with elite paddlers who: 

  • have a stroke that is (or previously was for several years) arm dominant 
  • rotate backwards  
  • tip their pelvis under  excessively (posterior pelvic tilt) when sitting in the boat for one or more of the following reasons; 

* they use a short seat-footrest distance so they can use the legs as something to pull against, rather than something to generate power from 

* they use a short seat-footrest distance because they struggle to ‘feel’ the footrest and legs with a longer distance which allows for full leg and hip movement 

* due to tight hips (or tightness elsewhere in the body), they tip their pelvis under to allow for more comfortable hip rotation 

* their local shoulder stabilisers are weak, so they help stabilise the shoulders using the upper back and pec muscles (which is easier to do in this pelvic position because rounding of the back changes the scapula and shoulder joint positioning)  

* their local shoulder stabilisers are too weak to support the extra force they would generate with more core contribution to the power of the stroke, so they tilt the pelivs to disengage the core

* their pecs are strong and overly tight, pulling the shoulders and anterior core muscles down and forward (and tilting the pelvis) 

* they have excessively tight hamstrings which pull the pelvis under when sitting 

* they find it uncomfortable to sit up on their sitting bones because of what is known the scientific community as S.A.S or ‘Skinny Ass Syndrome’. 

Other imbalances affecting the core 

It’s not only the stabiliser/mover imbalance that can get paddlers into trouble, other quite common imbalances to look out for are: 

  • strong hip flexors/weak lower abdominals 
  • strong posterior core muscles/weak anterior core muscles 
  • strong (or excessively tight) hamstrings/weak quadriceps (which can affect the angle of the pelvis) 

Continue Reading:

Part 6: Correcting core stabiliser/mover dysfunction