May I say this is a gem for every scientist and lifter in the world. The amount of knowledge in this video is unbelievable, well done Huange, you deserve much more audience! PS: in 2 weeks I'll start my first year in the sports study at uni and biomechanics will be a big class for me. Thanks for showing what biomechanics are and how exciting this subject is!
You can help avoid tears by A. Warm up the muscle. B. Increase resistance gradually C. Stretch D. Select load/weight with care, especially in certain exercises. E. Hydration and mineral balance. Not being hydrated increases the risk of tears. F. Heat/Cold. Being in a cold environment increases risk as well. These things help. But it can still happen if you overload the muscle. And like you show here in the stretch position it is the most vulnerable. Bear in mind also that any sudden snappy movement is also dangerous because as we know by studying physics- a mass coming to a stop with speed increases Force, by a lot.
Very interesting video! For the Chin Up problem, i think it is interesting to consider the horizontal forces that pulling on a fixed bar produces. Even if the forearm is completely vertical, the direction of force could be treated diagonally, creating a moment arm at the elbow. Menno Henselmans has a video about it, discussing the different Pull Up grips (around the 6 min mark, you can see a drawing). That could explain why Mathew's wide grip could cause his injury. Congrats on the hard work and thanks for sharing!
@@Huange._. Quick question, how many lbs in the isometric straight arm supinated DB hold to produce similar forces as in the rupture scenarios? And what would be the difference in the straight arm DB hold if you were lying down (so like a maltese, arm in line with body) vs standing (arm would be perpeendicular to torso at iso hold)? I've recently started training planche again and I'm taking my straight arm conditioning very meticulously this time around.
Yess huange! When u said something big was coming in the next week I had no idea it would be this good! Thanks so much man! This is so useful! Thanks Albert planchenstien!
Great work man, very detailed and comprehensive video. Thanks a lot for putting in the effort to explain all of this, I'm pretty sure it took a lot of time to gather all of this info and present it. Keep up the good work brother, much appreciated 👊🏻🙌🏻
have been viewing this folk's videos here and there but man this video deserves a subscription, looking forward to more in depth analyses on tears and other injuries
amaizing video, the production value is such that i thought it was a very high subscriber channel but i was wrong. Sadly views and subs doesnt equal quality, other wise you would have wayy more subs
I highly appreciate this masterclass type video. Thanks for educating us with all the necessary information in this video. Please do bring us more of such kind of videos. That'll be great. Mad Love brother. 💪🏼❤️ .
Really great analysis, chapeau! One thing I noticed is that you have to take the ratio for cross sectional area with the power of 2, since height is one dimensional and csa is two dimensional, assuming that a x-times greater body has a x²-greater csa with similar anthropometry. I also think that there is a significant dynamic component in the bottom of the hefesto, because its exactly at the turning point, where the acceleration is highest of the whole movement. However I very much appreciate your work, keep up the effort, this is some unique content, we calisthenics nerds waited for!
thanks for the comment, and interesting suggestion! It sounds like you're assuming that the radius or length/width of the cross-section scales linearly with a person's size, whereas I assumed that the area scales with their size. We'd have to look at the literature to see which assumption makes more sense, but I don't think there are any comprehensive studies on this topic for any muscle group, let alone for the bicep.
@@Huange._.the concept is called anthropometric scaling. Bone lengths scale linearly, CSA scales quadratic and Volume or weight scales cubic. There is pretty much scientific consensus about this in biomechanical research. It's also the reason why calisthenics is easier for shorter people and Olympic Gymnasts are short.
@@michaelk88 interesting! Can you share any literature that talks about the relationship between height and tendon csa? I wasn't able to find anything on that. If this were true, that would imply that shorter people have smaller cross-sectional areas of their tendons, not just linearly, but quadratically, which means their tendons would be significantly weaker than their taller counterparts.
What exactly causes the tendon to tear? The force generated by the biceps. The torque around the joint and the force generated by the biceps are not synonymous due to the different lengths of the internal moment arm of the biceps. Therefore, in the presence of a mechanical disadvantage but a more optimal length of the biceps fibers, a greater biceps force can be generated (compared to the longer biceps moment arm but less force generated by the fibers ) despite the presence of an equal value of the internal torque around the joint , even if in the case of an extended joint this would imply the presence of less external resistance. That is, it is the forces generated by the biceps fibers that cause the tendon to tear, and not the weight used as such.
Wow such a great video. Truly adding something unique to the Calisthenics community! Also excited to see you collaborate with Doctor Yaad who is also one of my favorites. Have you thought about adding errors bars to your calculation?
Thanks for saying that! Doctor Yaad is a super cool guy. I'm not super familiar with using error bars for this kind of analysis, but I don't think it would work here. Anthropometrics is unique to each person & I made a ton of simplifications (ie. ignoring the bicipital aponeurosis), so the error could be super duper high tbh. I just wanted to get a rough order of magnitude for my calculations that would be somewhat consistent with the research out there
Such an interesting video, the math is all way over my head but still enjoyed it all. I'm 190cm 90kg with a +100% chin-up as well, so it's one of my biggest worries. I've spent years progressing slowly so I just hope the tendon strength was built enough. I stick to relatively safe skills like front lever and handstand stuff. Always wanted to get some level of planche, maybe a super wide straddle, but I just don't think it's worth the risk.
glad you were able to enjoy it! 100% weighted chin at that bw is mad impressive. Ye planche can be pretty injury prone in general, so I get where you're coming from
34:53 I wonder if the pecs are involved during this point in the chin up to pull the shoulder into an internally rotated position for the body to direct tension more effectively into the biceps
Tore my left distal bicep of the bone 7month ago in BJJ, its an extremely shit injury to recover from. Still trying to get to previous size, strength and function.
Great video, I was surprised that proximal tears make up the vast majority of bicep tears, in strength training/bodybuilding distal tears get by far the most attention. I can't think of anyone who has torn their proximal biceps in the gym. Also, as most distal tears occur with the hand in a supinated position, what level of protection is afforded by using a less supinated position, in the preacher curl example that was shown, would an EZ curl bar have prevented that outcome?
My practical conclusion, because only few people, excluding myself as well, can work and understand these calculations completely is that: a) hand placements ect, details are highly relevant for load/force distribution on connective tissue. b) high load holds/reps are proportionally risky. Thus maybe having high specificity, low frequency + planned deloads and rare high load reps/holds in ones training might be the best practices to avoid such things. What do you think?
@@Huange._. Thanks for the feedback. I tried finding some relevant info, but turns out the research on deloading, especially for connective tissue health, is lacking.
@@benr5983 Yeah it's pretty tough to navigate the literature. A lot of relevant papers are stuck behind paywall subscription publishers, and sometimes you miss finding a useful study if you don't use the right keywords in your search.
Heavy resistance training in general will increase tendon stiffness. Just remember that tendons recover and adapt more slowly than muscles. For straight-arm stuff a lot of people do stuff like planche lean variations, dumbbell straight-arm stuff, etc.
Haung, your chinup analysis FBD equation is wrong. You took the addition of dynamic moments, yes, but not the static moments generated by the static load (independent of time, but only affected by range of motion). Your muscles exert significantly more getting some weight to a height, than accelerating said weight to a height. You keep discarding static moments and only add up dynamic (inertial) moments. To verify what I'm saying, figure out max CG vertical accel (ma) during an explosive chinup/pullup and see it's proportion to the total weight (mg).
Hi, thank you for the feedback. I believe I understand what you're referring to by "static moments," but I don't think that my approach was "wrong" given my assumptions. In my analysis, I assumed that the body's center of mass is directly under the bar throughout the chin-up (even though this may not be true at all joint angles), which means that the hand must exert a downward net force on the bar. Bc of newton's 3rd law, that means the bar must exert a vertical upward force on the hand. Given that I assumed the forearm is vertical throughout the chin-up, the upward force does not produce an antagonistic moment about the elbow. I also ignored any forces from the shoulder extensors that may produce an agonistic moment about the elbow, since I was focused on the bottom range of motion of the chin-up, where the line of action of these muscles basically passes through the elbow joint. In reality, I'm sure there is some degree of antagonistic moment that the biceps need to resist, but it's hard to quantify that. The line of action from any of the large forces that can produce a moment about the elbow is quite small in the bottom ROM, so I neglected them. I can even argue that the antagonistic moment produced by the bar is nullified by the agonistic moments produced by the shoulder extensors. Basically, if I had tried to account for the "static moments" you mentioned, it would be nearly impossible or potentially pointless to do any mathematical analysis. Lastly, you mentioned "figure out max CG vertical accel (ma) during an explosive chinup/pullup and see it's proportion to the total weight (mg)." I was aware that the vertical acceleration of the center of mass is directly proportional to the force the hands need to exert on the bar via F = ma. My vector loop analysis method did account for the vertical acceleration of the center of mass. I assumed that it translates up and down in a sinusoidal fashion, and that's how I got the angular displacements & accelerations of the elbow and shoulder joints. If the center of mass had a greater acceleration, the angular acceleration of the elbow & shoulder joints would have increased, which would have required a greater agonistic moment from the biceps. But just because the center of mass is accelerating faster doesn't mean that there's a greater "static moment." My assumption was that the line of action of any forces, internal or external, that can produce a moment about the elbow, was negligible. Once again, I appreciate the feedback. If you still disagree with my analysis, please feel free to attempt this problem using your assumptions and share it with me at huange.contact@gmail.com. I'd be interested to see your results and how they compare with mine.
@@Huange._. I might just do that, thanks for responding, man. But since that will require some effort, consider my simplified objection: If I asked you to randomly pause (no instantaneous velocity/accel at pause) between a intense, weight-loaded, pull up/chin up rep (somewhere between start and end ROM), would there need to be torque at the joints to keep you in that position? Would your posterior upper back and forearm flexors be isometrically contracting to hold you there? (Antagonistic muscles are not producing any counter torque, they're inactive: your anterior shoulder is not fighting the lats etc.)
@@user-pz3tk3tl6f great point. In a chin-up isometric, the biceps are definitely engaged despite the lack of an apparent antagonistic moment. This was one of my biggest points of confusion while doing this analysis. I challenge you to quantify ANY meaningfully large static moments that the bicep opposes in the BOTTOM ROM of the chin-up (where the elbow just starts to bend), because from a 2-dimensional point of view, it's difficult to come up with anything substantial. My current stance on this is that the bicep activation in the bottom ROM of a chin-up isometric has more to do with its role in supination than it does with elbow flexion. Due to the co-contraction of synergistic muscles in the chin-up, there's likely stray force vectors that induce a pronating moment about the forearm. I'd argue that the dominant role of the bicep in the bottom ROM of a chin-up isometric isn't to stabilize the body in a 2-D space, but rather a 3-D space. Same thing with the upper back & scapula. External rotation & supination in an overhead position is not a natural position to begin with, and when we introduce the co-contraction of a ton of different muscles, there's going to need to be stabilizing muscles as well. Obviously there's some component of elbow flexion here, as my assumption about a vertical forearm isn't 100% true, but in my opinion it's negligible. And to clarify, when I say "antagonistic moment," I am not referring to antagonistic muscles (ie. front delts). I know that these muscles are inhibited during loaded movement. I'm referring to any forces, internal or external, that produce a moment toward elbow extension, or in this case, pronation.
@@Limbaugh_ most people will be able to preacher curl 60 kg given the correct progression and healing. it's not about the weight, but how you got to that weight.
dude, thats calculations and researches are insane. how about adaptability limits of bicep tendon? i think this is also important topic in calisthenics theme. as you know most of pro gymnasts don't tear their tenons, because of good prehab, what do you think, can regular peoples hold maltese, even if once a month, just to test it out? and other time just training ay 70%
thank you. It sounds like you're referring to the upper limit of volume/intensity that you can train bicep exercises without risking injury, and this is unique to everyone. Work capacity and tendon/muscle strength can be built over time, and that's what high-level gymnasts do. They train fundamentals for 10+ years before doing hard events like rings.
@@Huange._. yeah, that thought about training only in safe range just clicked in my mind. few months ago ordered dream machine aka pulley system. have a talk with creator, he could do all advanced stuff like maltese and rings planche, and in the dialog he confirmed, that he doing unassisted versions only once a while, just to test his strengh! i was like holly shi, for real, most cali ahtletes going on max like crazy every session, it's like doing your PR bench every time, of course it would result in injury!
For us pea brain people, should we just assume that exercises that put the most tension when the arm is straight are dangerous? And are there any methods to prevent bicep tears while training for the planche or back lever?
sure. There's always a non-zero chance of getting injured in training. Learning how to program effectively and train w/ good technique are good places to start reducing risk. Diet, sleep, stress, fatigue etc are other things that can affect injury risk
There are a good number of proximal biceps tears in strongman, particularly of the proximal long heand. The main movement where this happens is atlas stones. A famous carrier altering example is Larry Wheels. th-cam.com/users/shortsjzNQP746MAI This type of tear substantially alters lifting mechanics due to destabilizing the shoulder joint and often can't be surgically fixed as the rupture tends to happen in the muscle and not the tendon coming off of the bone.
@@Huange._. That's kinda confusing for me, because I always read, that your bicep insertion doesn't affect your strength. Have I just been lied to the entire time? :/
@@Soteyka let's put it this way. If you have 2 people with different insertions, even if their muscle can produce the same amount of tension, the one with the better insertion will be able to lift more weight. So while the muscles themselves might be equally strong, the effect of the muscle contraction is amplified if people have a better insertion
@@zivbobi7920 google definition: Exercise rehabilitation is a type of treatment that uses exercise to help people recover from injuries or illnesses, and regain their strength and mobility. It's often used for people with physical impairments or disabilities, and can help them regain their ability to perform everyday tasks
hard to condense this into a yt comment. But I'll try a bit. 1. fatigue management - make sure you don't train super hard if not fully recovered 2. training intensity/volume - be mindful to not ego lift very often because the injury risk is higher. Higher volumes at higher intensities can also be prone to injury 3. warm-up/prehabilitation: making sure you're warmed up before difficult movements and taking time to condition your joints There's probably some good videos out there on YT on how to prevent injury, and I'm sure I missed some stuff.
I'm a mechanical engineering major. Most of the concepts in this video come from fundamental engineering classes like statics and strengths of materials and dynamics. The method I used for the chin-up came from a mechanisms class. I'm in my early 20s
@@Huange._. Cool brother, you're a bright guy and looks like you put a lot of effort into the video. Def earned a sub for what it's worth. I just kind of got into calisthenics 3 months ago, but I already had a very strong strength base from weight lifting. My training regiment was very sloppy until a few weeks ago so I hope to see some progress on the WPU, front lever, and planche. For ref, I can already do about 10 deep HSPU, Weighted dip 190lbs, and weighted pullup 1RM 140lb at a bw of 160. I could already do 15+ second back lever just starting out, maybe a 3 second front lever max, and i can only straddle planche 3 sec. Hopefully I can unlock the full skills for a 10 sec hold by April 2025.
@@Huange._. one final question bro if that’s alright. I saw you mention this in passing in another video (rpe 7=5 sec hold), but how would you roughly align the RPE scale to hold times for RPE 10-4? Is RPE10 1-2 seconds, RPE9: 3 sec? It’s kindof weird because is it measured by seconds in reserve or by ur max hold time for a given movement?
@@biblelorax rpe is relative to your max reps. For example, an RPE 9 is 90% of your max reps. For isometric holds, people generally consider 2 seconds = 1 rep. Hope this helps.
I shared a theoretical model for the tearing mechanics of the distal biceps tendon, and I attempted to quantify the stress in the distal/proximal biceps tendons in 6 cases of bicep tears. The stress values ranged from 29 to 74 MPa. This wide range of stress values implies that tendons can be strengthened with training to become stiffer by several times or more through training
@@Huange._. Ahhhh seriously thank you for explaining in simple words for my low attention span brain I have interest now in this topic and will watch full video
This is such an impressive piece. Bless your heart for putting your efforts in this field!
thank you doc!
May I say this is a gem for every scientist and lifter in the world. The amount of knowledge in this video is unbelievable, well done Huange, you deserve much more audience! PS: in 2 weeks I'll start my first year in the sports study at uni and biomechanics will be a big class for me. Thanks for showing what biomechanics are and how exciting this subject is!
Glad you took something away from it, and best wishes in your studies!!
@@Huange._. thank you!
this is fueling my motivation for an academic comeback
I never thought a walk to the store would be so interesting 😅 thanks for the information.
glad you found it interesting!
You can help avoid tears by
A. Warm up the muscle.
B. Increase resistance gradually
C. Stretch
D. Select load/weight with care, especially in certain exercises.
E. Hydration and mineral balance. Not being hydrated increases the risk of tears.
F. Heat/Cold. Being in a cold environment increases risk as well.
These things help. But it can still happen if you overload the muscle. And like you show here in the stretch position it is the most vulnerable.
Bear in mind also that any sudden snappy movement is also dangerous because as we know by studying physics- a mass coming to a stop with speed increases Force, by a lot.
Very interesting video! For the Chin Up problem, i think it is interesting to consider the horizontal forces that pulling on a fixed bar produces. Even if the forearm is completely vertical, the direction of force could be treated diagonally, creating a moment arm at the elbow. Menno Henselmans has a video about it, discussing the different Pull Up grips (around the 6 min mark, you can see a drawing). That could explain why Mathew's wide grip could cause his injury. Congrats on the hard work and thanks for sharing!
good point!
I literally just came out of listening to Mathew and Yaad's gornation Bicep tear video podcast and saw your comment there. Time to watch this!
wow, that's neat!
@@Huange._. Quick question, how many lbs in the isometric straight arm supinated DB hold to produce similar forces as in the rupture scenarios? And what would be the difference in the straight arm DB hold if you were lying down (so like a maltese, arm in line with body) vs standing (arm would be perpeendicular to torso at iso hold)? I've recently started training planche again and I'm taking my straight arm conditioning very meticulously this time around.
Yess huange! When u said something big was coming in the next week I had no idea it would be this good! Thanks so much man! This is so useful! Thanks Albert planchenstien!
thank you!
Your welcome! Thank you!
You are greatly appreciated!
thanks bro, you too!
Great work man, very detailed and comprehensive video. Thanks a lot for putting in the effort to explain all of this, I'm pretty sure it took a lot of time to gather all of this info and present it. Keep up the good work brother, much appreciated 👊🏻🙌🏻
thank you for the feedback!
Wow! That is an incredibly in depth analysis! Extremely interesting video. Thank you!
Hi Mathew, glad to hear it!!
have been viewing this folk's videos here and there but man this video deserves a subscription, looking forward to more in depth analyses on tears and other injuries
thank you!
amaizing video, the production value is such that i thought it was a very high subscriber channel but i was wrong. Sadly views and subs doesnt equal quality, other wise you would have wayy more subs
haha thanks
I highly appreciate this masterclass type video. Thanks for educating us with all the necessary information in this video. Please do bring us more of such kind of videos. That'll be great. Mad Love brother. 💪🏼❤️ .
glad you enjoyed it!
Really great analysis, chapeau!
One thing I noticed is that you have to take the ratio for cross sectional area with the power of 2, since height is one dimensional and csa is two dimensional, assuming that a x-times greater body has a x²-greater csa with similar anthropometry.
I also think that there is a significant dynamic component in the bottom of the hefesto, because its exactly at the turning point, where the acceleration is highest of the whole movement.
However I very much appreciate your work, keep up the effort, this is some unique content, we calisthenics nerds waited for!
thanks for the comment, and interesting suggestion! It sounds like you're assuming that the radius or length/width of the cross-section scales linearly with a person's size, whereas I assumed that the area scales with their size. We'd have to look at the literature to see which assumption makes more sense, but I don't think there are any comprehensive studies on this topic for any muscle group, let alone for the bicep.
@@Huange._.the concept is called anthropometric scaling. Bone lengths scale linearly, CSA scales quadratic and Volume or weight scales cubic. There is pretty much scientific consensus about this in biomechanical research. It's also the reason why calisthenics is easier for shorter people and Olympic Gymnasts are short.
@@michaelk88 interesting! Can you share any literature that talks about the relationship between height and tendon csa? I wasn't able to find anything on that.
If this were true, that would imply that shorter people have smaller cross-sectional areas of their tendons, not just linearly, but quadratically, which means their tendons would be significantly weaker than their taller counterparts.
perhaps you meant that the area and volume/weight scale inversely with height?
great video ! the work that has been put to this one is clearly impressive
thank you!
Bro you work so hard thank you for your efforts💪🏾🤝🏾
thanks!
not even watched 1 minute and already loving it, i'll follow up with a better comment at the end of the video
nice
What exactly causes the tendon to tear? The force generated by the biceps. The torque around the joint and the force generated by the biceps are not synonymous due to the different lengths of the internal moment arm of the biceps. Therefore, in the presence of a mechanical disadvantage but a more optimal length of the biceps fibers, a greater biceps force can be generated (compared to the longer biceps moment arm but less force generated by the fibers ) despite the presence of an equal value of the internal torque around the joint , even if in the case of an extended joint this would imply the presence of less external resistance. That is, it is the forces generated by the biceps fibers that cause the tendon to tear, and not the weight used as such.
ok
Quality content my guy.
thanks
I'm here Subbing before this video and your channel blow up.
:o
he's back! with a collab as well
:)))
bro that was soooo depth thank you we appreciate it ❤❤💯💯💯💯
thank you
Thank you for the video will be taking notes on this later
nice
Wow such a great video. Truly adding something unique to the Calisthenics community! Also excited to see you collaborate with Doctor Yaad who is also one of my favorites. Have you thought about adding errors bars to your calculation?
Thanks for saying that! Doctor Yaad is a super cool guy. I'm not super familiar with using error bars for this kind of analysis, but I don't think it would work here. Anthropometrics is unique to each person & I made a ton of simplifications (ie. ignoring the bicipital aponeurosis), so the error could be super duper high tbh. I just wanted to get a rough order of magnitude for my calculations that would be somewhat consistent with the research out there
rly good video idol. The athlete who tore his bicep in VG negative is Nico cambarau
ty remi!
Amazing video. Subbed. May I know what's your academic background?
thanks, mechanical engineering
such a good video
thank you
Love the content, keep it up! Thanks for the video, very informative!
glad to hear it!
Such an interesting video, the math is all way over my head but still enjoyed it all. I'm 190cm 90kg with a +100% chin-up as well, so it's one of my biggest worries. I've spent years progressing slowly so I just hope the tendon strength was built enough. I stick to relatively safe skills like front lever and handstand stuff. Always wanted to get some level of planche, maybe a super wide straddle, but I just don't think it's worth the risk.
glad you were able to enjoy it! 100% weighted chin at that bw is mad impressive. Ye planche can be pretty injury prone in general, so I get where you're coming from
Thanks!
Wow, thank you for the support!
Love your videos bro
thanks!
Sick vid you deserve more subs
thanks!
34:53 I wonder if the pecs are involved during this point in the chin up to pull the shoulder into an internally rotated position for the body to direct tension more effectively into the biceps
idk
The athlete at 25:20 for the Van Gelder is Nicolò Cambarau
@nico_cambarau
thank you!!!
Brodie is back🙌❤️
yooo it's been a while. Good to hear from you. How's it going?
Wow, outstanding video
thanks!
Wow, seriously good work
thanks!
Thanks for the video and now I know how to optimally tear my biceps
awesome
That one asian dude :🗿
🗿
wow, this is some next level broscience
:)
Tore my left distal bicep of the bone 7month ago in BJJ, its an extremely shit injury to recover from. Still trying to get to previous size, strength and function.
sorry to hear that, wishing a speedy recovery!
Subcribed!
nice
Very nice video, very informative
thanks
Hope you will do video with other muscles as well
maybe!
Great video, I was surprised that proximal tears make up the vast majority of bicep tears, in strength training/bodybuilding distal tears get by far the most attention. I can't think of anyone who has torn their proximal biceps in the gym.
Also, as most distal tears occur with the hand in a supinated position, what level of protection is afforded by using a less supinated position, in the preacher curl example that was shown, would an EZ curl bar have prevented that outcome?
a less supinated position would reduce the stress on the bicep, so maybe it could have prevented the double tear in that case
My practical conclusion, because only few people, excluding myself as well, can work and understand these calculations completely is that:
a) hand placements ect, details are highly relevant for load/force distribution on connective tissue.
b) high load holds/reps are proportionally risky.
Thus maybe having high specificity, low frequency + planned deloads and rare high load reps/holds in ones training might be the best practices to avoid such things. What do you think?
I agree w/ a and b! For your recommendation it probably depends on the individual athlete and their goals whether it's applicable or not
@@Huange._. Thanks for the feedback. I tried finding some relevant info, but turns out the research on deloading, especially for connective tissue health, is lacking.
@@benr5983 Yeah it's pretty tough to navigate the literature. A lot of relevant papers are stuck behind paywall subscription publishers, and sometimes you miss finding a useful study if you don't use the right keywords in your search.
Fantastic video!
Now I would like to know how to increase tendon stiffness to avoid injuries, any advice?
Heavy resistance training in general will increase tendon stiffness. Just remember that tendons recover and adapt more slowly than muscles. For straight-arm stuff a lot of people do stuff like planche lean variations, dumbbell straight-arm stuff, etc.
i honestly have no interest in this topic but feel like i should be watching it out of respect for the work put in
same
I love this vid, I also don’t understand a single word of this vid
same
Haung, your chinup analysis FBD equation is wrong. You took the addition of dynamic moments, yes, but not the static moments generated by the static load (independent of time, but only affected by range of motion). Your muscles exert significantly more getting some weight to a height, than accelerating said weight to a height. You keep discarding static moments and only add up dynamic (inertial) moments.
To verify what I'm saying, figure out max CG vertical accel (ma) during an explosive chinup/pullup and see it's proportion to the total weight (mg).
Hi, thank you for the feedback. I believe I understand what you're referring to by "static moments," but I don't think that my approach was "wrong" given my assumptions. In my analysis, I assumed that the body's center of mass is directly under the bar throughout the chin-up (even though this may not be true at all joint angles), which means that the hand must exert a downward net force on the bar. Bc of newton's 3rd law, that means the bar must exert a vertical upward force on the hand. Given that I assumed the forearm is vertical throughout the chin-up, the upward force does not produce an antagonistic moment about the elbow. I also ignored any forces from the shoulder extensors that may produce an agonistic moment about the elbow, since I was focused on the bottom range of motion of the chin-up, where the line of action of these muscles basically passes through the elbow joint.
In reality, I'm sure there is some degree of antagonistic moment that the biceps need to resist, but it's hard to quantify that. The line of action from any of the large forces that can produce a moment about the elbow is quite small in the bottom ROM, so I neglected them. I can even argue that the antagonistic moment produced by the bar is nullified by the agonistic moments produced by the shoulder extensors. Basically, if I had tried to account for the "static moments" you mentioned, it would be nearly impossible or potentially pointless to do any mathematical analysis.
Lastly, you mentioned "figure out max CG vertical accel (ma) during an explosive chinup/pullup and see it's proportion to the total weight (mg)." I was aware that the vertical acceleration of the center of mass is directly proportional to the force the hands need to exert on the bar via F = ma. My vector loop analysis method did account for the vertical acceleration of the center of mass. I assumed that it translates up and down in a sinusoidal fashion, and that's how I got the angular displacements & accelerations of the elbow and shoulder joints. If the center of mass had a greater acceleration, the angular acceleration of the elbow & shoulder joints would have increased, which would have required a greater agonistic moment from the biceps. But just because the center of mass is accelerating faster doesn't mean that there's a greater "static moment." My assumption was that the line of action of any forces, internal or external, that can produce a moment about the elbow, was negligible.
Once again, I appreciate the feedback. If you still disagree with my analysis, please feel free to attempt this problem using your assumptions and share it with me at huange.contact@gmail.com. I'd be interested to see your results and how they compare with mine.
@@Huange._. I might just do that, thanks for responding, man.
But since that will require some effort, consider my simplified objection: If I asked you to randomly pause (no instantaneous velocity/accel at pause) between a intense, weight-loaded, pull up/chin up rep (somewhere between start and end ROM), would there need to be torque at the joints to keep you in that position? Would your posterior upper back and forearm flexors be isometrically contracting to hold you there?
(Antagonistic muscles are not producing any counter torque, they're inactive: your anterior shoulder is not fighting the lats etc.)
@@user-pz3tk3tl6f great point. In a chin-up isometric, the biceps are definitely engaged despite the lack of an apparent antagonistic moment. This was one of my biggest points of confusion while doing this analysis. I challenge you to quantify ANY meaningfully large static moments that the bicep opposes in the BOTTOM ROM of the chin-up (where the elbow just starts to bend), because from a 2-dimensional point of view, it's difficult to come up with anything substantial.
My current stance on this is that the bicep activation in the bottom ROM of a chin-up isometric has more to do with its role in supination than it does with elbow flexion. Due to the co-contraction of synergistic muscles in the chin-up, there's likely stray force vectors that induce a pronating moment about the forearm. I'd argue that the dominant role of the bicep in the bottom ROM of a chin-up isometric isn't to stabilize the body in a 2-D space, but rather a 3-D space. Same thing with the upper back & scapula. External rotation & supination in an overhead position is not a natural position to begin with, and when we introduce the co-contraction of a ton of different muscles, there's going to need to be stabilizing muscles as well. Obviously there's some component of elbow flexion here, as my assumption about a vertical forearm isn't 100% true, but in my opinion it's negligible.
And to clarify, when I say "antagonistic moment," I am not referring to antagonistic muscles (ie. front delts). I know that these muscles are inhibited during loaded movement. I'm referring to any forces, internal or external, that produce a moment toward elbow extension, or in this case, pronation.
NGL losing both arms to 60kg would be maybe the most embarrassing thing that could happen to a man.
:o
@cheeks7050 why
@@garymadlon3028 It's 60kg bro
I know you can’t preacher curl that weight lol bro
@@Limbaugh_ most people will be able to preacher curl 60 kg given the correct progression and healing.
it's not about the weight, but how you got to that weight.
dude, thats calculations and researches are insane.
how about adaptability limits of bicep tendon? i think this is also important topic in calisthenics theme. as you know most of pro gymnasts don't tear their tenons, because of good prehab, what do you think, can regular peoples hold maltese, even if once a month, just to test it out? and other time just training ay 70%
thank you. It sounds like you're referring to the upper limit of volume/intensity that you can train bicep exercises without risking injury, and this is unique to everyone. Work capacity and tendon/muscle strength can be built over time, and that's what high-level gymnasts do. They train fundamentals for 10+ years before doing hard events like rings.
@@Huange._. yeah, that thought about training only in safe range just clicked in my mind. few months ago ordered dream machine aka pulley system. have a talk with creator, he could do all advanced stuff like maltese and rings planche, and in the dialog he confirmed, that he doing unassisted versions only once a while, just to test his strengh! i was like holly shi, for real, most cali ahtletes going on max like crazy every session, it's like doing your PR bench every time, of course it would result in injury!
Almost 40 minutes bro just say how to not tear a bicep
Great video! Ur arms look swole asf too
thank you
w video
thanks!
fire content
thanks!
Wow thanks
:)
For us pea brain people, should we just assume that exercises that put the most tension when the arm is straight are dangerous?
And are there any methods to prevent bicep tears while training for the planche or back lever?
sure. There's always a non-zero chance of getting injured in training. Learning how to program effectively and train w/ good technique are good places to start reducing risk. Diet, sleep, stress, fatigue etc are other things that can affect injury risk
@@Huange._. Thank you!
Do you prefer Konig theorem or Huygens Steiner?
don't know either
Cool man 🎉
thanks!
There are a good number of proximal biceps tears in strongman, particularly of the proximal long heand. The main movement where this happens is atlas stones. A famous carrier altering example is Larry Wheels. th-cam.com/users/shortsjzNQP746MAI
This type of tear substantially alters lifting mechanics due to destabilizing the shoulder joint and often can't be surgically fixed as the rupture tends to happen in the muscle and not the tendon coming off of the bone.
thanks for sharing, did not see this before!
great video. Are you still in the Navy reserve? your glasses look like the boot camp issued ones...lol.
haha they're normal glasses
so how do you prevent a bicep tear?
prehab/straight-arm conditioning and safe training practice
Does the bicep Insertion affect how injury prone your bicep is? I am sorry if it was covered in the video, I just couldn't understand a lot of it.
it affects your mechanical advantage, which affects your strength. And technically being weaker increases injury risk. So i guess it does
@@Huange._. That's kinda confusing for me, because I always read, that your bicep insertion doesn't affect your strength. Have I just been lied to the entire time?
:/
@@Soteyka let's put it this way. If you have 2 people with different insertions, even if their muscle can produce the same amount of tension, the one with the better insertion will be able to lift more weight. So while the muscles themselves might be equally strong, the effect of the muscle contraction is amplified if people have a better insertion
If I feel discomfort in the biceps during right hand exercises, can taking a week's rest help?
rest can help, rehab can also help. I made a video on calisthenics injuries which may be helpful. Best wishes in your recovery
@@Huange._. thanks, what do u mean rehab?
@@zivbobi7920 google definition: Exercise rehabilitation is a type of treatment that uses exercise to help people recover from injuries or illnesses, and regain their strength and mobility. It's often used for people with physical impairments or disabilities, and can help them regain their ability to perform everyday tasks
looking good huange
ty huang 🙏
wouldn't be here w/o u
any workout recommendations to avoid these tears?
hard to condense this into a yt comment. But I'll try a bit.
1. fatigue management - make sure you don't train super hard if not fully recovered
2. training intensity/volume - be mindful to not ego lift very often because the injury risk is higher. Higher volumes at higher intensities can also be prone to injury
3. warm-up/prehabilitation: making sure you're warmed up before difficult movements and taking time to condition your joints
There's probably some good videos out there on YT on how to prevent injury, and I'm sure I missed some stuff.
What about train full ROM? And avoid mixed grip deadlift?
For the algorithm
thanks!
Man youre the perfect asian (saying it as a compliment)
okay thank you
When an engineering student that is asian works out lol =) mechanical engineering student here haha
niiiice
Biceps*
Though I guess if one of the tendons tears it might actually be "bicep", not sure now.
Are you a CS & Physics major? Also, how old are you if I may ask?
I'm a mechanical engineering major. Most of the concepts in this video come from fundamental engineering classes like statics and strengths of materials and dynamics. The method I used for the chin-up came from a mechanisms class. I'm in my early 20s
@@Huange._. Cool brother, you're a bright guy and looks like you put a lot of effort into the video. Def earned a sub for what it's worth.
I just kind of got into calisthenics 3 months ago, but I already had a very strong strength base from weight lifting. My training regiment was very sloppy until a few weeks ago so I hope to see some progress on the WPU, front lever, and planche.
For ref, I can already do about 10 deep HSPU, Weighted dip 190lbs, and weighted pullup 1RM 140lb at a bw of 160.
I could already do 15+ second back lever just starting out, maybe a 3 second front lever max, and i can only straddle planche 3 sec. Hopefully I can unlock the full skills for a 10 sec hold by April 2025.
@@biblelorax thanks for the support. Sounds like you're super strong, keep it up bro!
@@Huange._. one final question bro if that’s alright. I saw you mention this in passing in another video (rpe 7=5 sec hold), but how would you roughly align the RPE scale to hold times for RPE 10-4?
Is RPE10 1-2 seconds, RPE9: 3 sec?
It’s kindof weird because is it measured by seconds in reserve or by ur max hold time for a given movement?
@@biblelorax rpe is relative to your max reps. For example, an RPE 9 is 90% of your max reps. For isometric holds, people generally consider 2 seconds = 1 rep. Hope this helps.
Guys has anyone watched full video and can explain in short to me?
I shared a theoretical model for the tearing mechanics of the distal biceps tendon, and I attempted to quantify the stress in the distal/proximal biceps tendons in 6 cases of bicep tears. The stress values ranged from 29 to 74 MPa. This wide range of stress values implies that tendons can be strengthened with training to become stiffer by several times or more through training
@@Huange._. Ahhhh seriously thank you for explaining in simple words for my low attention span brain
I have interest now in this topic and will watch full video
do you eat beans?
sometimes
Yeah Idont understand a thing 10:17
same
@@Huange._. 🤣