Thursday, April 27, 2017

Strokes notes: Thinking outside the Box

If you've ever taken an introductory kayaking course, you've heard of the "Paddler's Box." The Box is one of those classic fundamental rules of kayaking, and it's generally considered critically important for protecting yourself from injury--particularly shoulder injury--while kayaking. Many of the most common errors of paddling technique can be ascribed to doing things outside the Paddler's Box. 

If you've somehow managed to avoid being introduced to the Paddler's Box, here's a link to a short but helpful videoAnd here's how the instructor in that video describes the Paddler's Box for those watching:
"The Paddler's Box is a rectangle that we create between our arms, our paddle, and our shoulders."


OK, so things are a bit clearer if you watch the video. But still, maybe we can find something a little more descriptive. How about this, from Jackson Kayak's paddle education site:
"The Paddler’s Box is the rectangle shape that can be traced from the hands, up the arms to the shoulders, across the chest and back down the paddle. It is the rectangle that is created by our upper body, arms and paddle shaft."

That's a little better, though we'll see in a moment that it's incomplete. Here's a simple diagram that might help, from the blogger and whitewater kayaker brthomas:

So we can kind of see where the rectangle is there. Its four sides are the shoulders, the two extended arms, and the paddle. Maybe it's more of a trapezoid than a rectangle, but that's ok. And from the video and a number of these websites we get the sense of how to maintain the Paddler's Box. Here, from
"The paddler’s box moves with you as you rotate your torso, and it is generally important to stay within the box as you paddle."

So the box always stays out in front of you, even when you rotate to the left or right. The idea behind the Paddler's Box is that it forces you to think about getting your body in position for a stroke--any stroke--by rotating your torso rather than reaching with your hands and arms. It's supposed to keep you from doing things with your hands that you just shouldn't do, like reaching behind you to place the paddle for a stern rudder. This is, without question, a good thing. So I can appreciate the desire to have a rule that communicates this important principle of good paddling. Unfortunately, I think that the Paddler's Box may not be the best way to achieve that goal. 

I've never been fully comfortable with the idea of the Paddler's Box, for two reasons. First of all, I find the Paddler's Box extremely difficult to visualize. The diagram and descriptions above, though pretty typical, provide me only with a Paddler's Rectangle at best. Here's a more three-dimensional attempt to describe the box, from a site called ThoughtCo:
"When the hands are on the paddle and extended out in front of the paddler, the paddler’s box can be traced from the hands, up the arms to the shoulders, and including the chest and paddle contained within these constraints. This shape should roughly approximate a square. Now, extend those dimensions and shape down to the boat and that gives you the paddler’s box...Maintaining the paddler’s box simply means not allowing the hands to extend past the shoulders on either side, but they can move up or down within this imaginary box."

So the Paddler's Rectangle gets projected down to the deck of the boat, and this forms the Paddler's Box. It's a rectangular cube, and I'm supposed to keep my hands inside of it. That's actually not bad, I can see what the box is and how I'm supposed to use it. But it wasn't particularly easy to get to this point. And it brings me to the second reason that I don't like the Paddler's Box: For many skills, even demonstration-quality skills, the kind that you'd want your students or fellow paddlers to emulate, I'm pretty hard pressed to say whether or not my hands are inside my Paddler's Box. In other words, even when I think I can visualize the Box, I'm still not really sure what I'm allowed to do with my hands. Think of a good sculling draw, for example. Here's an image of someone demonstrating the stroke from the Necky Kayaks paddling skills website:

Where's the Box? Is his upper (left) hand outside of it? It's certainly above his shoulder; it seems to be level with his forehead. What about his right hand, which appears to have moved outside the box to the right? Or has it? I'm at a loss to explain to someone whether or not this paddler has maintained his Paddler's Box. But I don't think he's clearly doing anything wrong. 

In short, I find the Paddler's Box complicated to explain, difficult to visualize, and nearly impossible to apply to many skills. So what's the alternative? Here's my proposal for a rule to replace the Paddler's Box:

Never, ever, ever, under any circumstances, allow your elbow to go either above or behind your shoulder. 

I believe that this rule covers every possible violation of shoulder safety that the Paddler's Box is meant to cover, and I think that it's also simpler to understand and simpler to implement. Here are a few examples of things paddlers do that I think should never be done:

  • Finishing the forward stroke with the arms instead of using good rotation
  • Reaching above the head for a high brace
  • Reaching behind the back for a stern rudder instead of rotating
  • Reaching across the body for a draw stroke instead of rotating

In every single case, I think that following the rule above would prevent the paddler from committing these errors. A good efficient forward stroke should eliminate the pull-through with the arms that causes your elbow to go behind your shoulder. If your elbow goes above your shoulder for a high brace, you're asking for injury. The only way you can get the paddle placed for a stern rudder without putting your elbow behind your shoulder is to rotate aggressively toward the paddle. And the guy above demonstrating the sculling draw is just fine; he's rotated so that he can keep is right elbow in front of his right shoulder and his left elbow at or below his other shoulder. 

Unlike the Paddler's Box, which is so challenging to communicate that in five minutes of googling I managed to find at least four variations, this rule has the great benefit of simplicity. And, even better, to implement the rule I get to refer to things that actually exist. So instead of trying to figure out if the stroke keeps my hands inside some imaginary box, the limits of which are baffling to describe and literally impossible to see, I just have to look at where my elbows are in relation to my shoulders. 

The big remaining question is whether or not this rule does all the work that I want it to do. Can you think of an instance in which you'd feel justified in breaking the rule? Can you think of a movement that would put your shoulder at risk that wouldn't be prevented by applying it? If you can, I'd be interested to hear about it. If you can't, then maybe it's time we stopped worrying about the Paddler's Box, and started paying more attention to our elbows.  

Tuesday, April 4, 2017

Strokes Notes: Hanging on the paddle

Cross-over paddlesports are more popular than ever, with many kayakers expanding their skills by moving from flatwater to whitewater (or vice versa), or by trying out stand up paddleboard or canoeing. Unfortunately, there is one sport that I rarely see mentioned in discussions of these alternatives: rowing. I suppose I can understand why this blind spot exists. Unlike kayaking, rowing is primarily aimed at mastery of a single stroke, which seems contrary to paddlesports in which the goal is more complete control over a much more maneuverable vessel. But I'd argue that rowing has a great deal to offer the kayaker. There is something to be said for millions of repetitions aimed at perfection of a single stroke; specifically, it tends to develop a deep feeling of connection between body, boat, blade, and water, a feeling toward which all paddlers should strive.

I think that there may be one particularly valuable lesson that rowing has to offer the kayaker. It centers on a key concept in rowing: “hanging on the oar.” Here is a quote from Todd Jesdale, onetime U.S. Mens' Junior National rowing coach:

"A rower needs to find ways to have the push and power of the legs go directly to the oar handle, with little interruption. Simultaneously, one must realize that every ounce of power applied to the oar handle must emanate from the footstretchers, that there is a one to one connection between push against the footstretchers and pull on the oar handle. So, when one pushes very hard with the legs and keeps various parts of the body from giving way or breaking, one moves the oar handle as well."

Replace "oar handle" with "paddle shaft" and "footstretchers" with "footpegs," and I believe this statement captures something critical at the heart of the kayaking forward stroke. It also explains many of the ways in which kayakers routinely fail to exploit the full efficiency of that stroke.

To get an idea of what Jesdale means, take a look at Figure 1. This figure presents a series of images from a video clip of Rob Waddell, a rower with multiple World Championships and an Olympic gold medal to his name. These images show the "drive" segment of a single stroke, from the catch in frame 1 to the release in frame 8. Notice that from frames 1 to 3, for the first half of his stroke, it's ALL legs; the angle of the back is constant, and there is no break in his arms. Frames 4 and 5 finally see the back swinging toward the bow (remember, as a rower he's facing backwards), and only in frames 6-8 do we see him finish with his arms.

Figure 1. The drive segment of the rowing stroke.

This progression--legs, back, arms--allows Waddell to transfer every bit of the power that he is exerting on the footstretchers to the handle of his oar. Here's another way to view it: As his legs drive against his footstretchers and push his hips toward the bow, the strong back forces his shoulders to keep up with his hips, and his straight arms force his hands (and the oar handles) to follow his shoulders. This is most apparent in frames 1-4. Everything is tied together, and the result is that the leg drive is perfectly transferred into movement of the oar handle. Only after the power phase of the drive is complete do the arms come into play at all; by frame 5, the power of the stroke has diminished enough that Waddell can begin to effectively engage his arms to complete the stroke and release the blades from the water.

The connection you can see in Waddell's stroke, the unbroken transfer of power from the legs through the back and arms to the oar handle, is precisely what Jesdale refers to in his description, a description that is typically abbreviated with the coach's exhortation for the rower to "hang on the oar." Hanging on the oar is the way that the rower harnesses the power of the water pushing against the buried blade to move the boat forward efficiently. The feeling of hanging on the oar is similar to the feeling of hanging from a pullup bar; the weight of the body can be felt through the extended arms and down through the large muscles of the back (the "lats"). This is exactly where the power is felt in the upper body during the first half of the drive.

Now imagine, instead, that Waddell allowed the connection to break down. Imagine if the back was weak, and collapsed forward as the legs drove the hips back. The result would be a disconnect in the transfer of power; the legs would drive, but the oar handle wouldn't move. Or imagine if he tried to grab at the catch with his arms. Instead of transferring the power of his leg drive efficiently by using the biomechanical advantage of his extended arms, he would be trying to transfer that power through his contracting biceps--and even Rob Waddell doesn't have biceps strong enough to fully transfer the power of his leg drive. The transfer would break down. The result in both cases is a loss of power and a reduction in efficiency of the stroke.

What does any of this have to do with kayaking? Let's take a look at another world class paddler: Anders Gustafsson, a World Champion sprint kayaker. Figure 2 shows a series of video stills from one of Gustafsson's practice sessions. There are a great many similarities here to Figure 1. The most important for our purposes can be seen in frames 1 through 4. In these frames Gustafsson's right leg drives his right hip back in the seat and he uses the rotation of his torso to keep the shoulder following the hip. The extended right arm provides the connection that keeps the paddle shaft moving right along with the shoulder. The result is an unbroken connection between the leg drive against the foot stretchers and the movement of the shaft, a perfectly efficient transfer of power. Gustafsson is "hanging on the paddle" through this entire motion. By frame 5 the leg drive is complete, and the blade is nearing Gustafsson's right hip. At this point, nearly all of the power of the drive has been expended, and the remaining rotation of the torso and bending of the right arm is primarily serving to extract the blade cleanly from the water to finish the stroke.

Figure 2. The drive segment of a kayaking forward stroke.

The same opportunities exist here for the transfer of power to break down. If, for example, Gustafsson's torso rotation was weak, his leg would drive his right hip back but his right shoulder would lag behind and fail to move the paddle shaft. Similarly, if he were to grab immediately at the catch by bending his arms he would be asking his biceps to transfer the power generated by the large muscles of his legs and back, an impossible task. Only by hanging on the paddle, by maintaining the connection through his lats and extended arms, is he able to efficiently transfer the power needed to drive the boat forward at top speeds.

In thinking about problems that kayakers might have in maximizing the efficiency of their forward stroke, I have come to the conclusion that many of them relate to a failure to hang on the paddle. Consider the following, for instance. One of the best ways to cultivate the ability to hang on the oar in rowing is to take strokes using only leg drive. Since the back and the arms remain static, this allows the rower to eliminate (or at least limit greatly) the possibilities of breakdown in connection throughout the drive. The same drill exists for kayaking. It's called the straight arm drill. Just about every kayaker who has ever taken a formal class, especially one focusing on the forward stroke, has done the straight arm drill. And most people absolutely hate it. I have found that most paddlers have trouble doing the straight arm drill properly--almost everyone wants to break the arms. But what's really interesting is that even when people are successful at keeping their arms straight, they often can do so only by sacrificing nearly all the power in their stroke.

Why? My theory is that many kayakers’ forward strokes involve engaging the arms immediately after the catch. Instead of hanging on the paddle and allowing the extended arms to transfer power efficiently from the leg drive to the paddle shaft, this approach relegates all power to the biceps, which means that the stroke is limited to what the biceps can bear. (Interestingly, this limitation can exist even if the paddler appears to be rotating well with the upper body, and in some cases even if there is drive on the foot peg. In other words, it’s difficult to diagnose this problem with the standard markers that we use for a good forward stroke.) The problem is that in this case the leg drive and the rotation are being compromised by the instinct to initiate the stroke by grabbing at the paddle shaft with the arm. For anyone that paddles this way, the straight arm drill is crippling. Since power transfer for them normally depends on engaging the biceps, removing that muscle group from the stroke eliminates virtually all power. In contrast, a paddler who consistently hangs on the paddle should be able to paddle at nearly full power with the straight arm drill; any limitation would be associated only with the mechanics of the release, which involves bending the arm to cleanly extract the blade from the water.

What is the cure for this problem? First and foremost, the paddler must cultivate the feeling of hanging on the paddle shaft. Some visualizations might first help to illustrate the technique. Imagine, for instance, that you're trying to pull-start a reluctant lawn mower. You don't just lean over, grab the handle, and pull the cord with your biceps. You'll never get enough power doing it that way. You put your foot on the lawnmower and you bend your leg to get leverage; you extend your arm fully, reaching your shoulder down toward the mower; and when you pull, you drive that shoulder back up with a strong push on your leg and rotation of your torso, and you let your extended arm do the work of making the cord handle follow along. That's the only way you'll get that rusty old thing started, by hanging on the handle and using the big muscles of your legs and your torso instead of your biceps. When people know they need to efficiently apply power, they instinctively apply every available biomechanical advantage. The challenge is to transfer this instinct to the forward stroke.

The easiest way to develop this feeling in the boat may be to take strokes in conditions where the resistance of the stroke is great enough to prevent grabbing with the arms. The most convenient place to find that resistance is in the first few strokes from a dead stop, overcoming the inertia of a stationary boat. If the paddler prepares appropriately for the first stroke--one hip forward, knee raised and foot placed firmly on the foot peg, torso rotated and on-water hand extending out with a straight arm, blade planted fully at the catch--and then takes a full power stroke by driving hard with the leg and torso rotation, it will be nearly impossible to grab with the arm and bend the elbow. The paddler should feel the power transfer from the big muscles of the legs and core, through the lats, and down the underside of the extended arm. This is the feeling of hanging on the paddle that the paddler should seek to replicate with every stroke. The paddler can repeat this exercise simply by letting the boat come to a full stop after every initiating power stroke; or, if there's a willing partner, by having that partner stand behind the boat in shallow water and simply hold onto the stern to keep it from moving. Other ways to find the kind of "heaviness" that reenforces this feeling is to paddle hard in very shallow water or to engage some kind of artificial drag or anchor, possibly by towing another paddler.

The other worthwhile exercise, obviously, is the straight arm drill itself. If you look at frames 1-4 of Figure 2, you'll see pretty clearly that Gustafsson's regular forward stroke is basically a straight arm drill for the entirety of this power phase of his drive. The biceps are not generating power, they are simply finishing off the stroke and facilitating a clean release. The straight arm drill will be most effective, obviously, once the student has cultivated the feeling of hanging on the paddle (perhaps with resistance drills as described above); that feeling can then be carried over into the straight arm drill until the paddler can move the boat efficiently throughout the drill. (The other challenge with the straight arm drill is that eliminating the elbow bend in the last third of the stroke makes it extremely difficult to achieve a clean finish. There is, fortunately, a very simple solution to this problem: just shorten the stroke. Simply extract the blade earlier, before you would normally begin your finish by bending the arms (say, just after frame 4 of Figure 2). Do the straight arm drill using only a half stroke, slicing the blade out early enough that you're not tempted to break the arms to get a clean finish.)

Once you've cultivated the feeling of hanging on the paddle shaft, it becomes something that can be easily employed as a "self-check." A paddler hanging on the paddle will feel the tension running like a cable that stretches along the underside of the extended arm, through the lats in the upper back, down the muscles lining the core and into the driving thigh. This is a proprioceptive marker just as effective as any visual marker of good forward stroke technique. It is a marker that is used constantly to gauge stroke efficiency when rowing, but I think its value has not been appreciated by kayakers. As a former rower and current kayaker, I frequently check myself to make sure that I'm hanging on the paddle, and it has been a critically important component in the development of my forward stroke. I highly recommend that you give it a try.