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☺️ appreciate the kind words; thank you for watching!

Thank you and glad you enjoyed. The common body movements might be a topic worth exploring more in the future as I didn’t really have a chance to go more in depth; I just wanted to mention it to show possibilities beyond thinking purely about fundamentals. I probably think more in terms of common threads between body movements now than I do fundamentals when it comes to finding themes in common with a group. Not that that’s a better way of thinking, just one that works well for me.

@@Nedito17 Thanks for watching Ned! Still happy to chat soon after I missed your phone call. Hope to see you on snow soon!

@@mikethomas4391 thank you so much Mike! I moved to Vermont largely to be apart of this team about 5 years ago. It’s an awesome place if you want to get better! Where do you ski out of now?

@@attiliorighini9289 cheers man, I appreciate the feedback! Glad you enjoyed it and I’m currently working on a direct to RUclips (not a webinar recording) series to expand on this.

Alfonso, that was partially a mistake on my part during editing. I searched for and added the author's credits to each video used with the overlayed text and accidentally missed yours. Let me figure out what I can do to correct this.

Jeff, I followed you on Instagram. Shoot me a message sometime and let me know what you have in mind!

@@BrandonBock I just put a friend request in Facebook

Definitely. Funny enough, I tried leapers for the first time on skates this summer at a Skate to Ski event w/ Rollerblade. I have a long-time hockey background so I was fortunately able to get the hang of it on skates and begin to experiment pretty quickly. One of the most interesting things to me in that context had to do with pressure and how I was able to get a rebound-like effect on skates that made the "leap" far easier, helping make me lighter in transition, in a way that the leap wasn't created just from me jumping like you would ideally do on skis. There's no sidecut or bending or unbending of the ski going on there; it was all in the timing and amount of pressure, the turn shape, and controlling the path of the center of mass relative to the base of support to create that effect.

Yes, pressure can be created and sustained by tightening the turn radius, but the discussion here is in the context of transition

@@karlo407 the context of the comment was how you can control pressure during transition by what you do before transition.

@@BrandonBock I was commenting on Lawrence’s post. I understood it to be a comment on the guest’s discussion about the limits of how much pressure can be developed (not much, and very transitory). Lawrence changed the context to pressure developed while in a turn.

Thanks for coming man! (P.S., Dave also does car videos. Check out his channel if you're into that)

I'm the first person to admit that I suck but going around the internet making comments like this is an even rougher look than my skiing 😂

@@BrandonBockwhat level were you in 2020?

@@peterfreeman3317 I said it in the video. What does it matter anyway? What constructive point does a comment like this make?

@@BrandonBock in my opinion a full cert instructor should be able to rip and ski any conditions on any trail with top form.

Glad you enjoyed it Gerrianne. I definitely thought it was a really cool perspective Angelo was able to provide on how to use something we often see as a boring series of documents as a tool to develop as an instructor.

Glad you enjoyed it and got something out of it from a snowboard perspective. The whole joystick analogy, at its root, was actually inspired in part by working with and listening to snowboard trainers which gave me new perspectives on how to think about skiing. The physics of how we get our planks to perform is exactly the same but we come at it from such different perspectives sometimes and stand to learn a lot from each other.

Thanks for watching and appreciate you taking the time to comment! Really glad to hear that feedback! More to come soon!

You seem to bring a lot of problems to the table but none of the solutions. Why can't you explain the mechanics? Not sure what I'm repeating from 40 years ago considering I wasn't even alive then to hear it 😉

In which ways do you notice? I have very limited experience with SUPs as I’ve only done it twice, but I do spend a lot of time looking at other sports and how they move. Really helps sort out good athletic movements from contrived movements you’ll only hear inside ski circles.

@@BrandonBock when there are high waves, I need to keep my knees bent to allow absorbing completely independent from upper body movement because I need to remain balance and still be able to paddle the same time. When the waves tilt the board to the max, I need to actively extend my legs to get the board back to horizontal in a control the way and still keep my knees bent .Ideally, anticipating the waves, but still need to deal with them only when they hit the board. And certainly head over my toe, but remaining whole foot on the board for the balance. Meanwhile, there is a limit of friction under foot, and there is no speed and Centrifugal force to hold me on the board, therefore slipping and overboard is part of SUP.

@@BrandonBock There are videos about paddle in surf saves.

@@snorfallupagus6014 but what if dragging my poles is my primary turn force? 🤯🤣

@@alfonsoeae thanks Alfonso! Love what I’ve seen you putting on Instagram as well. I was actually thinking about messaging you in the future to get some insight on how you’re doing your 3D anatomy visuals.

@@BrandonBock whenever you want... The last models are really amazing, I can show almost anything I want from a skeleton, muscular, body ski to a skier in ski suit... Audio done movements into the boots... I studied physics at university and I've enjoyed very much this webinar...

@@alfonsoeae Awesome, I appreciate it! I've had aspirations of doing some similar 3d anatomical visuals but I haven't had the time to figure out how I'd do it yet. I'll reach out on Instagram soon!

@@ИгорьКазуров nice to meet you! I was noticing some Russian viewers in the video stats.

@@BrandonBock Я инженер по образованию, мне интересно разложить сложные системы, на простые понятные детали, у вас аналогичный поход. Я хочу перевести ваше видео на русский язык, озвучить его и выложить на своем канале, если вы даете мне разрешение на данную работу. В декабре этого года я буду проходить обучение на инструктора по горным лыжам и проверю вашу методику на себе. ))

Janos, I appreciate your time watching the video and providing feedback as I wish to create more videos on the subject. I would ask you to consider the following: 1) In any form of education, one of the most critical skills that define what makes a great educator is identifying student needs and adjusting their plan based on the needs of the student. I'm not claiming to be the best educator, however, the intent of this webinar was not to provide a comprehensive understanding of the physics of skiing, as that was neither the needs of the students I was targeting nor possible given the time constraints of the webinar format. The vast majority of ski instructors will never need a perfect, in-depth understanding of physics to coach at even the highest levels of skiing; nor will they have the time to study it since, at least in the United States, most ski instructors are part-time with other careers. The students I was targeting were instructors with little-to-no background in physics with a lack of interest in the subject due to the boring/dry nature of the subject or the aforementioned lack of time. My goal was to provide a simple and slightly more entertaining (relative to the underlying subject) analogy to an audience with no background in physics that gets across the vast majority of the physics concepts needed to understand the "why" behind "how" we ski. 2) I understand and acknowledge in the video that neither gravity or inertia are "forces" and when I use terms like force of gravity and inertia, I am referring to the forces DUE to gravity and the forces due to inertia. I purposely use simplified words and descriptions because my goal is not to communicate words, my goal is to communicate ideas and help instill a better understanding of those ideas. Words and language are limiting in our ability to communicate ideas and unfortunately, some ski instructors fall into the trap of using big words because they place a higher priority in proving to their students "what they know" rather than prioritizing the needs of their students and what they need to do as a teacher to help educate and provide value to them. 3) I do not mean this in an insulting way as the fact you're multilingual is something you've got on me 😅; but I think there may be a mild language barrier that's making your point difficult to understand, so excuse me if I'm misinterpreting you. Your book you are advertising doesn't seem to cover this either. My concern with what you seem to be saying is that centrifugal force you reference is a fictitious and perceived force that does not exist in our world. Centripetal force, as I mentioned in the video, does exist, but its opposite is not centrifugal force in any real-world frame of reference and only exists in a rotating frame of reference. While I will be the first to admit my understanding of physics is not infallible, my understanding is that most of the forces that act upon us in skiing can be attributed to forces DUE to gravity and DUE to inertia and, like most forces, those force vectors can be added together into a net force. I'm more than happy to be wrong as my goal is never to be right, it's to get it right so that I can understand ideas better and be a better educator. However, your explanation doesn't really make sense based on my current understanding. I unfortunately cut it out of the recording due to copyright concerns and respect for the creator, but this comic was originally in the webinar around 24:20 to have a little fun with this exact debate: xkcd.com/123/

@@BrandonBock I think your main point is, that simplifications are good and useful. I agree. But you have a responsibility when you create simplifications. If your statements become wrong, because the opposite of this statement is true, you must rethink and create better simplifications, otherwise you will just confuse yourself and your audience. In this case you choose to leave out the centripetal force and the supporting N force of the skis. But this is no good, because the centrifugal force cannot be used to interact with the G force when it has a zero value. Also if you choose not to talk about the centripetal force, you leave out the most important force that our skis deliver to our body in all ski-turns. When your body gets to the side of your skis, the edges of the skis start to work and they deliver the centripetal force for your body. Without edgings of the skis and inclination from the skis, there will be no ski-turns. Against G force we use the supporting force (N force) of the skis and against the centrifugal force we use the centripetal force. I suggest you never mix up these things.

​@@JanosKoranyi Okay, I understand your point better now. While I don't entirely agree and some of that may just be a language issue, I do see how I could explain this better in the future because of you and appreciate your comment for it. My goal was never to present a complete full body diagram of every force acting upon the skier, but rather to provide a simplistic view on why we inclinate and, more importantly, how much we inclinate. While the inclusion of centripetal and normal forces in this talk would provide a more complete and accurate picture, I don't see a lot of practical application in knowing those forces that the average ski instructor can walk away with and go out and apply to a lesson or in their own skiing. While centripetal force may be the lateral force we are balancing against and responsible for much of why and how much we inclinate, it doesn't allow for an easy visual nor is it what people "feel" when turning. People can understand what they feel better, and they "feel" the force of gravity and feeling of intertial forces; not centripetal or normal forces, which are far harder to relate to and understand. Additionally, the visual of a diagonal line that originates from the center of mass is far easier to see and understand in terms of determining how much we inclinate based on the centripetal force rather than directly showing the centripetal force line. I will think on this going forward on how I can maintain the same simplicity and relation to what skiers "feel" while improving the way I describe these concepts to prevent any misunderstandings. Thanks for the chat and your time, Cheers🍻

@@kenvonfelten9494 as someone originally from a small ski school in PA who knows the struggles that can be involved, hearing this comment makes me super happy! Where are you from, Ken?

@@BrandonBockCurrently Saddleback , but have been at several smaller as well, Camden Snowbowl, Labrador, GreekPeak, Kissing Bridge. Having said that there are / were some great trainers at those resorts but what you provide is a great addition … Thanks again

Hey, thank you! I appreciate all of the kind words and feedback. This webinar should have been broken into two parts but by the time I realized what I should have done, I had already committed to the topic and didn't have enough time to adjust so I definitely glazed over some details and oversimplified in others for the sake of not turning this into an even longer webinar than it already was. To your points: 1) The simple version of the way I think about femur rotation as it relates to extension vs flexion in transition is that the more perpendicular the femur is with the ski, the more femur rotation results in ski rotation/steering. The more parallel the femur is with the ski, the more that femur rotation becomes an edging movement. So if you're standing up with the knee and hip extended so that your femur is essentially perpendicular with your foot (or the ski if we were on snow), the femur rotation rotates your foot internally, assuming fixed tibia rotation. If you sit down so that your femurs are parallel with your foot and the floor, that same femur rotation will start to lift the feet off the ground and starts rolling the feet side to side. Any kind of femur rotation in between fully extended and being flexed to that parallel femur orientation starts to blend the two movements and when combined with tibial rotation can result in a lot of options between edging and ski steering. 2) Always interested in more reading material on the subject; we don't have a lot of in depth *scientific* material specific to the ski instruction world. The second sentence of the abstract about "our scientific understanding of how the underlying mechanics of alpine ski racing technique relate to performance is surprisingly weak" is so true. Actual scientific approaches to understanding this sport are definitely something I want to see more of; way too much "because that's what my trainer told me and now I tell everyone as if it's undeniable truth" dogma that may or may not be true out there. 3) I'm actually planning on doing another video more focused on this specific topic soon and appreciate your arguments here. I was very time limited in this presentation. I actually don't disagree with you on this point, but another point that I raised in the video but may not have done a great job of communicating is that the muscles involved in the lifting the outside edge of the ski up and the muscles involved in pulling in the lower leg in general are not particularly strong. These are muscles I actively train in the gym to strengthen for skiing, but I load somewhere in the range of 30 lbs for 10-15 reps at a time. Admittedly, there's a lot of anecdotal evidence behind my argument, however, my intuition when considering that we are relying on these small tipping muscles of the foot/ankle to lift a ski that I am balancing 200 pounds of human (for myself) over with the addition of turn forces on top of that suggests to me that there could be strength limitations, especially in the vast majority of the general population that probably don't specifically strength train these muscles. Especially when considering the hundreds to thousands of repetitions of this movement a skier may do in an average day, I would venture to think that the muscles would not be able to reliably and accurately repeat the movements at the level expected in high-end, technical skiing. And in my own, anecdotal experimentation, my logic seems to transfer on snow experimenting on both myself and when observing ski instructors I train seeing fundamental differences in their movement patterns simply by changing ski width. There may be some nuances in terms of moment arms and leverages that I'm failing to account for in my logic, however, my main point is not that it can't be done, it's that I question if it's the best, most repeatable, and/or most efficient way. To me, it's significantly easier and more accurately repeatable especially during a long day of skiing to use physics and forces to my advantage by using a narrower ski rather than have to actively and significantly strain a weaker muscle with a wider ski in less appropriate (i.e. firmer) conditions for that type of ski. I definitely left out some nuances in this webinar due to the aforementioned lack of time and will revisit it soon in a RUclips-specific more refined video. I've heard of your cited study and will read it more in-depth, but I did actually purposefully choose to leave the knee health arguments out. While too wide of skis on firm snow do actually cause issues with my own knee pain thanks to some past injuries, it seems to be an argument that falls on deaf ears with a huge portion of the ski population. My brief skimming of the study though seems to suggest more forces being transferred through the knee and into the thigh muscles on a wider ski, which to me further represents my point that pulling the outside edge of the ski up is not enough to overcome the forces required to tip the ski on edge. I would be super happy to be wrong on this topic quite honestly; as I said before, we need more measured, scientific, and objective looks at these topics by people far smarter than I 😅 4) Cool topic idea! I will keep that in mind. I actually have some other perspectives on that topic to go along with it as well. Thanks again for watching the video and taking as much time as I'm sure it did to write your comment.

​@@BrandonBock Thanks so much for taking the time to write that detailed reply!. I'd planned to respond sooner, but wanted to give what you wrote the consideration it deserved-lots of good stuff there!-so I put it aside for a few days, which then turned into a month :D. Anyways: 1) You wrote: " So if you're standing up with the knee and hip extended so that your femur is essentially perpendicular with your foot (or the ski if we were on snow), the femur rotation rotates your foot internally, assuming fixed tibia rotation." My thinking (and this may be the same as yours) is that, when you tip when standing extended on skis, the feet don't rotate relative to the ground, since they are constrained by the skis. Instead, your feet stay pointed in the same direction, so your tibias and femurs rotate into the turn. When I do this standing, I find this causes my pelvis to also rotate into the turn, which would result in a loss of counteracting (CA). [As expected, this doesn't happen if tipping when flexed.] If I do the tipping aggressively, I can actually impart an inward rotational momentum to the pelvis, which could result in a rotary action. But I suspect that people who use rotary aren't tipping so agressively to start with, and thus to the extent you see rotary initiation, it's due to a whole-body movement rather than from tipping when extended. In summary, the main issue I see with tipping when extended isn't that it directly creates rotary initiation, but rather that you lose the angle creation, and that it causes loss of CA. Your thoughts? Is there something I'm missing about how tipping when extended could create rotary initiation? This still leaves me wondering about the next part of the kinetic chain, which is the pelvis. I think we have a clear picture of how tipping when flexed can create knee angulation. But how does this then propagate to the pelvis to create hip angulation? And is there a difference between tipping when extended vs. flexed for this? 2) Agreed! 3) OK, got it. And I agree with what you wrote here. I didn't understand what you were thinking of, which is that ankle fatigue can result from repeated tipping of wide skis on flat snow, until I read your response above. That's probably because I don't use wide skis on flat snow, so this never occurred to me! Instead, that's something I'd encounter only intermittently on my pow skis, when I end up on firm patches. I can feel ankle fatigue in those situations, but it's more acute than chronic, e.g., if they're on edge at the bottom of a turn on a firm patch on a steep slope. So that's an isometric fatigue. And I can feel actual ankle discomfort if the skis break loose and then suddenly grab. So I think it's just a matter of presentation--making it clear that the above is what you mean, rather than that it's impossible to tip a ski when its edge is outside your boot sole. I.e., you'll want to rephrase statements like this (at ~1:07:30) : "...this is this is only possible...this tipping motion because my forefoot and the base of my boot are wider than the width of my ski and that allows me to direct my pressure past the edge of my ski...". I see now that you instead meant: "...this *easy* tippping motion is only possible...." 4) Another way to think about this is in terms of torque (cribbed from something I wrote elsewhere): When you ski, you create a ground reaction force (GRF), which results from your resistance against the force due to gravity plus the centripetal force from the turn. We can describe that force using a vector whose origin is at your base of support (BoS; let’s assume it’s somewhere near your outside boot), and that angles inward (towards the inside of the turn) and upward. Now imagine another vector that goes from your BoS to your CoM (note this is a location vector, not a force vector). In the middle of the turn, those two vectors typically point in nearly (but not exactly), the same direction. Their mild divergence generates a mild torque that you use to increase or decrease your inclination. However, as we approach the switch, and move our CoM closer to our skis, the direction of the CoM vector deviates strongly upward from the GRF vector. This divergence creates a substantial push + torque against our legs that, unless dissipated through flexion, creates the float. [As you know, if you push on an object anywhere other than towards its CoM, you'll create a torque.]

You're right, and we do ultimately get to that conclusion. Although, in my particular case it was more of a pressure management issue resulting in extension in transition as my only option as opposed to the extension being the root cause. "Pole vaulting" over the downhill leg, as I like to call it, was a very long-time known issue in my skiing. I'd been getting that feedback since very early on in my ski career and despite my efforts to fix it, it took several years after I got my level 3 before I had figured out the root cause and actually how to solve it. Thanks for following along and watching Marshall!

@@BrandonBock Brandon, I’d noticed the pole vaulting as you call it. I don’t understand why the extension in transition was your only option at that time? I noticed the issue right away because it seems to me to be a common issue. Perhaps you’d be kind enough to explain to me how you were able to rid yourself of doing it so I can help students? //Marshall

​@@gogglebro9421 Absolutely. For a little extra context: This extension based transition and "pole vaulting" primarily occurred on steeper pitches in shorter radius turns where turn forces were higher and there was less time to manage them. If you put me on less pitch and/or it was a longer radius turn, I could more effectively flex into transition. I knew I needed to flex through transition more so I had room to progressively extend as you mentioned Patrick did a good job of, I just couldn't no matter how hard I tried in this context. The were a few reasons preventing me from flexing more, but there were two main "game changers" for me that ultimately helped me break through the barrier I'd been trying to overcome for years. The first was that I was finishing my turns essentially with 100% of my pressure on the outside ski with little to nothing on the inside ski. On pitch, at speed, in a short turn, it was simply too much force going through one leg to flex the leg and my body was instinctually bracing against that force with a long leg since that sends more force through the skeletal structure than the muscles as when you're more flexed. You can actually see a couple turns in the video where as I finish the turn, majority of weight on the old outside ski, my new outside ski actually comes off the ground and all of my weight is still on that old outside ski that becomes my new inside ski after transition. The fix for me was starting the process of weight transfer earlier to the inside leg coming out of the apex BEFORE it became my new outside leg. So, by the time I was finishing my turn and entering transition, my weight distribution between my feet was closer to 50/50 and now I was splitting the load of managing that pressure build up at the end of the turn more with both legs instead of essentially trying to do a one legged squat on skis like when I had all of my pressure on the old outside ski. I had also discovered my inside ski at the last second, at the end of my turns, was sliding forward, causing my ankle to open slightly and for me to start my turns too heel heavy on what became my new outside ski after turn transition. I am NOT a feeler, at least as far as internal sensations go and being as this was so subtle, I was not feeling this happen at all. What I do feel and what is very intuitive to me though is what the ski is doing and how it is performing. Since I was starting my turn on the heel of my new outside ski, I was instinctually and very quickly opening my knees and hips to shift my weight forward and get the tip to bite more at turn initiation, compounding the quick extension issue. The fix was keeping that inside ski more under me at turn finish so I was starting more in balance on it as it became my new outside ski. I could probably write a dissertation on this with more reasons but some of them are way better shown visually than through text; might be worth a more focused video on the subject. Ultimately, managing the pressure better as I skied into transition and fixing that little fore/aft glitch unlocked the ability for me to more consistently flex through transition, which then allowed me to get more of the progressive extension in the top of my new turn and more speed control out of the top of my turns, which then lightened my pressure management load even more at the end of my turns. This may not be the case or the issue for everyone, most people just extend by default because it's easier in a lot of ways. But for me, those two details were at the core of it for me when the turn forces were higher. Hopefully I made that clear. Happy to clarify anything if need be.

Brandon, thanks for the thorough explanation! It must have taken a bit of time to elaborate in such detail. I too find it challenging to do short radius turns on a steep run and standing up to release the skis to turn is not the best solution to deal with it. I also find an active inside ski (keeping it under me) is important. My one question right now is did you figure out why your ski was slipping forward at the end of turns?

@@gogglebro9421 I'm more than happy to talk ski nerd and being a small channel still affords me the opportunity to engage with everyone 😀 I think I was just so focused on what the outside ski was doing and trying to get it to flex more at the end of my turns that I neglected and got lazy with my inside ski. I never really thought about what my inside ski could be doing to help my outside ski do what I wanted it to do, and ironically, that ended up being part of the solution. I was just losing tension around that last little bit of the turn and that inside leg was inching forward right before transition. I talk about this a little bit more in the Practical Biomechanics and Physics video but I started basically pulling back on that inside foot as I finish my turns (and continue to do so as it becomes my new outside foot at turn initiation) using hamstring contraction to help keep the ankle more flexed. It "feels" like I'm driving my foot into the back of my boot, almost like I'm trying to slide it backwards across the footbed or across the floor back towards you as you sit in a chair; except, it doesn't actually slide inside my boot...it's moreso pushing my shin into the front of my boot by pulling my foot back. It serves a bit of double duty for me as it fixes the fore/aft issue and also helps a bit with the other issue I mentioned of starting to transfer foot-to-foot pressure since it's almost like wedging the ski back underneath me. It may or may not help everyone but it was a cue that worked for me and helps support the smaller/weaker ankle muscles.

Thank you! Glad you enjoyed it.

It's on my radar but not yet, unfortunately. I'll have to get on some of our snowboard trainers to help put something together this winter! I'm primarily a skier but it was actually snowboarding that inspired some of the analogies in this webinar.

Thanks Josh, Cheers! 🍻

Yup! We’re around Killington pretty much every weekend in May.