Slidewinder wrote: ↑November 28th, 2022, 3:13 pm
I have thought a lot about rowing ergometer handle design, probably more than anyone here, probably more than Concept 2. There are various design goals that need to be considered. Injury prevention is important. There are others. Little has been said or written on the question, "What stroke geometry should be enabled by a rowing ergometer handle?"
Most RowErg users, if asked what rowing stroke is most closely replicated when using the stock C2 handle, will reply that it is closest to a sweep stroke. Well, I suppose it is similar to a sweep stroke in that it is pulled and pushed and both are rigid sticks. But with respect to stroke geometry, the stock C2 handle enables neither a sweep nor a sculling stroke. With the former, the handle moves through a single large arc. With the latter, the handgrips (plural) move through two large arcs. So, with respect to replication of OTW rowing, the C2 handle does very poorly. Since the C2 RowErg is used worldwide as a training tool for rowing athletes it would be a better training tool if the rowing handle design enabled a better replication of an OTW stroke geometry.
What rowing stroke then should the handle design aim for? Should it be a sweep or a sculling stroke? Well, back to the design requirement of injury prevention. In consideration of that, a sculling geometry would seem to be the preferred choice. Look at freeze frames of both sculling and sweep athletes at points throughout the stroke. The sculling stroke appears the most fluid and natural - the two large arcs of movement, perfectly balanced and symmetrical; the hands, wrists, and forearms remaining in alignment throughout the stroke, from catch to finish. A sweep athlete, however skilled, always looks crabbed, angular, and awkward at the completion of the stroke.
So a sculling geometry is what we should aspire to in the design of our rowing ergometer handle. Rowers have been perfectly replicating a sculling stroke on the Coffey rowing machine for decades. It incorporates oar stubs pivotable at their outer ends, a vaned flywheel mounted flat behind the rower, dynamically balanced movement, everything dimensioned and configurable to match an actual rowing shell. Users call it the closest thing to being on the water while still being on dry land. A similar device, the BioRower is now available, but it was Calvin Coffey, a former U.S. rowing Olympian who came up with the idea, patented it, and has been quietly building and selling his beautiful machines for the last 30 years. But we are not looking to re-design the entire machine. We want a rowing handle design that will connect to the single pull chain or strap of a typical rowing ergometer, and give us a better sculling replication than the standard, single-piece, rigid handle.
The simple cable loop/bicycle handgrip configuration I describe in my Nov. 24 post in this thread is a good solution. It is crude, but it works fine. For someone with shop skills the idea can be embodied in a more aesthetically pleasing structure. Either way it enables the basic geometry we seek. It should be configured so that when you hold your arms straight in front of you with your hands in a vertical position you will appear in your pose as if you are holding and aiming two pistols. There should be a slight angle between the handgrips and the pistol "barrels". Pistol makers know that this is the most comfortable, neutral, non-stressed, relaxed, ergonomically correct position for the hands. Take a piece of large dowel in a relaxed grip and extend your arm. You will notice that the dowel is at a slight angle to your wrist, just as the handgrip of a pistol is not perpendicular to the barrel but at a slight angle. This is the hand to wrist position that we want the rowing handle to maintain throughout the stroke.
Back to our cable/handgrip assembly. If the cable distance from the centre of the handgrip to the chain swivel connector is adjusted to be around 11" to 13", then as the stroke progresses the handgrips will naturally spread apart as your arms move from an extended position to a retracted close-to-the-torso position. Your hands, wrists, and forearms will remain in alignment with the direction of applied force, and your handgrip to wrist position will always maintain that pistol-grip relationship. But here is the interesting part: As the handgrips move apart as the stroke progresses, if we were to temporarily fasten a short stub to the outer ends of the handgrips (the stubs representing an oar shaft), we would see that the handgrips and the "oars" move through an angular progression in relation to ground, very similar to the angular progression of the handgrips during actual sculling! So not only does this configuration maintain an ergonomically correct hand to wrist relationship throughout the stroke, but fortuitously, the handgrip movement is a close approximation of the stroke geometry of OTW sculling.
Some naysayers will scoff and point out that only one-half of the sculling stroke is being replicated. During sculling the rower's arms are spread wide at the catch. True enough. But as of yet, no one in the patent record has solved the mechanical problem of obtaining a full sculling stroke from a handle with a single attachment point to the pull chain. The Coffey rower, described above, will give you a full sculling stroke, but that is not a single-point handle attachment design. With the described simple cable/handgrip configuration we can replicate the latter half of a sculling stroke. That is a huge improvement over the stock C2 rigid, single-piece design, which, other than moving forward and back, replicates nothing.
One final note: Probably more people use the C2 rowing ergometer for general fitness than those who use it for OTW training. The described cable/handgrip configuration enables not just a sculling stroke, but other non-rowing stroke geometries. For example, the handgrips can be rotated from horizontal to vertical as the stroke progresses, or, held vertically throughout the stroke. These movements are not rowing related, but they are nonetheless viable exercises, engaging other muscle groups, and adding variety and interest to the workout program. This opens up the machine beyond its current limits. You are a rowing athlete - go ahead and row. You are a fitness buff - mix your workout up a bit. As I wrote earlier, those with shop skills could add structure to the design and enhance the look, feel, and performance of the design. The rowing ergometer experience could be much, much better than it is. Why, after forty years, is everyone still pulling on a rigid, single-piece handle?