Body Lean

How far does a paddler need to lean forward with their trunk to get a long pull?  How much lean is needed for a strong pull?  Probably not as much as you’d think.

Why Armpit to Gunnel Doesn’t Help

What propels the boat?  The paddlers.

How do paddlers propel the boat?  They use their paddles.

Like I’ve mentioned in previous posts, the paddle blade is the business end.  Skillful paddlers can impart both great work and control to their paddle blade as it moves through the water.  Remember that work is defined as force over a distance.  Pulling the paddle faster through the water requires greater force.  The limits of human arthrokinematics and equipment leverage along with a paddlers physical strength determine some max value for work.  It probably looks like a bell-curve.  A paddler is only as strong as they are at that moment, but paddling technique has everything to do with paddling efficiency to reach the peak of that bell curve.

If you’re thinking of paddling from the perspective of how a paddle interacts with the water, the goal becomes how to move your body in a way that applies max leverage to the paddle through some optimum amount of paddle travel/displacement.  Several things happen when a paddler leans all the way down to the gunnel:

–  They lose reach at the paddle blade resulting in a shorter pull.  While it’s true that full lean to the gunnel may put the outside/bottom hand at its farthest forward distance from the bench, it doesn’t mean the same for the paddle blade (the business end).  Full lean takes away from our spinal mobility.  When your joints are taken to a maximum range in one direction, it becomes more and more difficult to move in other directions.  In this case, full trunk flexion takes away from rotation.  Try sitting in a chair, leaning forward and rotating your trunk to either side (don’t hurt yourself).  Now sit up straight and rotate in place.  You can probably rotate farther sitting up than curled over.  Decreased trunk rotation during the reach puts both hands at a similar distance from the bench, making a more vertical paddle angle on the entry, cutting actual reach at the paddle blade.

–  They have less strength.  Leaning forward fully during the reach puts most muscles used in paddling on full or very stretched position.  Glut max, hamstrings, lumbar extensors, lat dorsi, teres major, deltoids, rhomboids/mid and lower trapezei are out of their optimum zone for force production.  Your muscles are happiest and strongest in their mid-range.  For a simple example, think of curling a heavy weight.  It’s tough to start the lift from elbow fully extended and, when you’re fatigued, most folks struggle to get the weight all the way up to finish the rep (elbow fully flexed).  This is because 90 deg of elbow bend is about the middle of the elbow flexor muscle length (and coincidentally the joint angle of about the most mechanically efficient line of pull).

–  They are slower paddlers.  Sitting up from a fully reached position on a pull requires bringing up your whole trunk.  This takes a lot of time and energy because your trunk is a long lever arm.  Think of a long pendulum and how it swings slower than a short one (or takes much more force to swing faster than a short pendulum).  Slower movement sets paddling rate limitations.  When you’re racing fast, the water moves fast and you need to be able to move your paddle faster than the water to exert force on it.  Using a slow body movement like trunk flexion and extension will cap your ability to hold a faster rate to meet fast hull speeds.

LARD’s logo paddlers armpits look close to the gunnel, but don’t be fooled. Their racing technique is very crisp, constrained, efficient, and FAST!

How much lean is optimal?

The short answer is it depends.  The long answer is that there is no one answer and it depends.  (ha)

I am an advocate for a paddle stroke that has minimal trunk flexion/extension during the stroke and relatively more degrees of rotation.  My reason is that rotation allows for the paddle blade to get more positive on the catch and set the blade more forward than a negative/neutral angle, which increases the length of pull (possibly allowing more work to be performed).  Rotation is also mechanically more efficient for generating force to the paddle because the distance of your shoulders to your spine is less than the distance of your shoulders to your hips (shorter torque arm for rotation means less of a mechanical disadvantage compared to hip hinging alone).  One thing I am not a proponent of is sitting straight up and paddling.  It sets your shoulders way above the water line and, with it, your paddle resulting in less water contact and a shorter pull.  It also makes you work harder to resist the forces against the paddle (trunk as a long lever arm resisting paddle force at 90 degrees is the most mechanical disadvantage you can face).

I’ve never really paddled OC, but the stroke generally seems much more constrained than the typical dragon boat technique being used by local rec teams.  Part of the reason for less body excursion and more paddle movement is for energy conservation, which makes sense to me with OC’s racing for many miles.  I can see how allowing *some* increased trunk excursion may be desired in DB because the power gains may outweigh the need for energy conservation when you’re racing for sub 2 minutes or a 100-500 meter race.

On a side note, I think this is one of the reasons why senior/masters level teams can do as well/better than some youth teams is because masters paddlers may have 1) better water “feel” 2) physically less ability to flex their hips/spines so default to more rotation 3) better strength from a longer history of resistance training.

4 responses

  1. Jacob de Feijter

    As you say, ‘it depends’. You also say ‘they have less strength’, that is only correct for the portion of increased length of the stroke. Power=force x distance so we should always aim to maximise that. If leaning more adds some distance, it is worthwhile as long as it does not diminish the power in the original stroke. The other factor to consider is the time ratio between paddle out of the water and paddle in the water. If you can lean more without lengthening the time out of the water, then it is likely to be worthwhile.
    The only way you’ll know for sure is to test it. An erg machine is OK, but you will get more accurate information if you can dynamically measure the force on the paddle and the stroke length.

    November 19, 2013 at 2:15 am

    • Geoff

      Hey Jacob! Ah, the pursuit for the Holy Grail of “best” stroke technique. I think the key here is really that good stroke technique depends on so many factors and there are many ways to achieve good performance. I agree that testing is the only useful way to know if changes made to technique are really amounting to improved objective performance. Thanks for posting! Always a pleasure.

      November 19, 2013 at 4:02 pm

  2. Jacob de Feijter

    After posting I had some doubts and decided to check some videos I recently took of 20 Breast Cancer Survivors during individual paddle tests. (partially loaded boat, only 1 paddler paddling over a fixed distance). I simply assigned 0,1,or 2 depending on the amount of lean and did the same for ‘twist’. With 2 being armpit to the gunwale or close to it. The ‘Max lean’ group had a 17% quicker time than the ‘No lean’ group, ‘Some lean’ 8%.
    ‘Max twist’ 5% quicker than ‘No twist’ and ‘Some twist’ 1%.
    Of course these measurements are somewhat subjective and sample size was small. I also looked at only 2 or 3 strokes for each. I had expected that Twist would have more impact but results were erratic. The 4 paddlers that had Max lean combined with No twist had a quick time, a slow time, and two average times. So other aspects of technique and of course pulling force play a big role. Lean had a much higher correlation with boat speed.
    I am hoping to repeat the test with some other teams later this summer. It’ll be interesting to see what results we get.

    November 19, 2013 at 11:06 pm

    • Geoff

      While I think there are strong advantages and a bit of common sense to choose the technique that yields the best initial and theoretical performance, I am a firm believer that a wide variety of paddling techniques can yield great performance when paired with proper training. If your paddlers stuck with their technique “groups” for 4+ weeks, how would their performance profiles diverge or would they? Always an interesting experiment, but hardly productive given the general timeline of most teams’ racing seasons. Good luck finding the stroke that works best for your team, Jacob!

      November 21, 2013 at 1:29 pm

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