Lever systems in the human body

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After watching this video session, it is expected that you will be able to
Define levers.
Enumerate the main uses of levers
Identify the three classes of levers
Give mechanical examples of each class of levers
Compare the mechanical advantage of the three classes of levers
Give anatomical examples of each class of levers
Explain why the second-class lever at the ankle joint is the most suitable for its function.
Discuss the fact that third-class levers are the most common in the body
0:00 Introduction
0:05 Definition and Uses of Levers
1:44 Types of levers
1:55 First-class levers
3:03 First class levers anatomical example
3:33 Second-class levers
4:29 Second class levers Anatomical example
5:10 Third-class levers
5:50 Third-class levers anatomical example
Presented and edited by Dr. Akram Jaffar (Ph.D.).
This video and its channel are supported by the "Human Anatomy Education" Page on Facebook / anatomyeducation
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Опубликовано:

27 июл 2024

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Комментарии : 125

@fitnessmaximabdb6815 5 лет назад

LOVE this video! Great in-depth explanation along with helpful visuals and straight to the point!

@shayadubin1844 8 лет назад

Thank you Dr Jaffar for your very clear explanation of the 3 lever types. Much appreciated.

@akram.jaffar 8 лет назад

+Shaya Dubin Thank you and best wishes!

@justinpierzchala8494 9 лет назад

Great video very helpful, thank you!

@shimmyology 10 лет назад

Really helpful, thank you.

@danak9594 9 лет назад

This is a very illuminating video, thank you

@TinqXP 6 лет назад

Thank you for the video , much appreciated

@ipdconvipack7899 9 лет назад

Thank a lot Dr.Akram I really appreciate your simple and effective explanation

@leenakar1462 4 года назад

Thank you so much Dr. This was the best and easiest definition of any lever

@ChrisStaff 4 года назад

Thanks for this video. The clarity of these examples are excellent

@yousefza5551 9 лет назад

thanks a lot Dr. it was very helpful and i was trying to know lever class used on knee and ankle which the exact examples you included :)

@RodneyMarquezFishingChannel 8 лет назад

Best description of what the differences between class levers. Thanks you -Therapist

@akram.jaffar 8 лет назад

+Rodney Marquez Thanks!

@jeon0169 6 лет назад

really good description now i feel ready to identify levers in the body

@subrataray5371 4 года назад

Thanks for your video 😊😊

@Laotzu.Goldbug 5 лет назад

Very solid video, thank you Doctor Jaffar.

@uncannysin 3 года назад

I just started learning this topic in biomechanics, this was very helpful

@akram.jaffar 3 года назад

Glad it was helpful!

@user-uy8ex1uk9q 8 месяцев назад

10 years later and this video is still fantastic! Great explanations:) Thank you!

@akram.jaffar 8 месяцев назад

Glad it was helpful!

@drbonesshow1 7 месяцев назад

Facts are always facts unless shown not to be facts. That's a fact. Words of wisdom from a physics professor involved with the Physics of Sports.

@njwildberger 9 лет назад

I wonder if the example of a hammer is not also partly a type 1 lever: thinking of the lever along the direction of the handle, with the fulcrum in the middle, and the nail the weight at the end. We can see evidence for this point of view in that the length of the handle certainly affects the effectiveness of the hammer over-all. Thanks for the nice video!

@ReneGrothmann 9 лет назад

One other comment: To contract more than a few cm is impossible by a muscle. Muscles simply do not work that way. So the body has to resort to third kind levers to get a limb to travel a bigger distance.

@coachronhelpingtoheal7135 6 лет назад

Great video, but you are correct. The claw hammer is a first class lever.

@koreanseriessingha6070 5 лет назад

Bed

@TimpBizkit 5 лет назад

@@ReneGrothmann yeah most places in the body apart from the back of the jaw, the muscle is strong but only moving a short distance. Leg muscles are probably producing the weight of half a car or so over 3 inches to lift your body 1-2 feet.

@tomvilar1753 9 лет назад

Great Video! Thank you!

@gajalakshmi776 5 лет назад

Thank so much for your vedio I'm from tamilnadu

@tcubaseball11 8 лет назад

thank you oh so very much Dr. Akram Jaffar!! wow very understandable, again thank you a million.

@akram.jaffar 8 лет назад

+Oscar Pena You are welcome. Best wishes!

@michaelaworona4037 3 года назад

could someone please correct me if i am wrong? at 2:38, the video says Mechanical advantage > 1 but according to the formula given of Force arm/Resistance arm, or 50kg/100kg, the result would be 0.5 which is not >1. similarly, the video also says Mechanical advantage < 1 , but Force arm/Resistance arm yields a result of 2, which is not

@asmaasaid1656 8 лет назад

جزاكم الله خيرا

@antoniosantiago9503 6 лет назад

Thanks for this amazing video.

@hootanvakili9009 9 лет назад

excellent explanation, great job Dr Jaffar

@torpacio 8 лет назад

That was great. Thank you!

@gabbyhaar4243 4 года назад

this was amazing. thank you so much!

@interstellarinc 9 лет назад

fab video - thanks

@Mo95793 8 лет назад

Sorry but a small corretion a clawhummer nail system is a second class lever. The resistance hand or load is the nail but the force hand is actually the handle of the hammer , it moves a greater distance compared to the nail, hence delevering a higher force.

@Laotzu.Goldbug 5 лет назад

Correct. I noticed this as well, I think it might be the only mistake in the video.

@Laotzu.Goldbug 5 лет назад

Close, but not quite. You are right that he made a mistake, but you also have made one. A claw hammer - nail system is not a second-class lever, but in fact a first-class one. Because the pivot point - the head of the Hammer - 6 between the effort arm, the handle of the hammer, and the resistance arm, the nail. It's a little bit confusing, because the lever is at a 90-degree angle, instead of being a straight line, but the same principle still applies.

@peybak 4 года назад

To your last point, I remember calculating the tension on the back muscles required to lift a certain weight during a dead lift. I was shocked at the results.

@nate8396 2 года назад

What was the result?

@khushboodalal3587 10 лет назад

helpful, thanks!

@mohammedhjmtm7593 6 лет назад

Thank you very much ❤!!

@Waliul_The_Wall-E 6 лет назад

that was very helpful

@jaykrishnatirupati7311 5 лет назад

best classification ever

@MaximFit 10 лет назад

Thank you for posting your lecture. Would your head example at 3:32 also be a 2nd class lever when the muscle force and resistive force act on the same side of the fulcrum (lower part of the head) to tilt the head backwards?

@GravisTKD 10 лет назад

An example of how it could be technically applicable (and I realize this is a little specialized, but it works) would be if you are hanging upside down. If you try to lift your head "up" in either direction (think flexion or extension of the cervical spine). Gravity will try to pull your skull back toward the neutral position you started in, and it will act on the SAME side of the joint that's moving as the muscle that's doing the work. Put another way, the cervical extensors will try to extend the cervical spine by pulling on the posterior side of it, and the weight of your head (the resistance) will try pull it back into flexion, and that force of gravity will also be posterior to the joints in question. Interestingly, whether the muscle action in this scenario is characterized as a 2nd or 3rd class lever will depend on how far from neutral your head goes. The muscle might start as a 2nd class lever (having a greater moment arm/mechanical advantage than the resistance) and eventually switch places as the head, and thus its weight, gets farther away from neutral. Hope that makes sense.

@dheerajbaji8990 8 лет назад

Thanq sir for your good and clear explanation i have clarified my doubts

@akram.jaffar 8 лет назад

+Baji Dheeraj You are welcome!

@jzwillows Год назад

When the entire hammer with hand applying force us included in the example of the hammer pulling out the nail, it is an example of a first class lever, and thus, per the first class lever mechanics, the required force applied by the hand to pull out the nail is reduced with length of hammer handle.

@danyadanya1079 8 лет назад

wow u r a great doctor👍 thanks a lot👌and keep going please💐💐

@akram.jaffar 8 лет назад

+Tabark Faiz Best wishes

@danyadanya1079 8 лет назад

+Human Anatomy Education ur welcome 💐💐

@jamesjalali6338 7 лет назад

Thank you, come again

@amansaiyad7177 5 лет назад

Best video ever

@osamaselim2607 4 года назад

الله يباركلك :)

@1983duka 10 лет назад

good information...

@p.z.8355 4 года назад

But why do the muscles need to move a shorter distances in the third kind of lever systems ?

@p.z.8355 4 года назад

Since Work is defined as Force times Distance, the higher Force neccistates less Distance for the same amount of Work

@afjalurrahmanradil6130 3 года назад

Thank you sir.......👌

@akram.jaffar 3 года назад

Most welcome

@ajeetkumartiwari9264 10 лет назад

Helpful thank u

@AlabasterPeacock 2 года назад

Good explanation, thank you

@akram.jaffar 2 года назад

You are welcome!

@akram.jaffar 10 лет назад

Maxim Fit , it should be, but how could this be technically applicable?

@anikatultul7291 7 лет назад

it was so helpful ^_^

@yanling60 3 года назад

Awesome vid

@akram.jaffar 3 года назад

Thank you!

@prachisharma7128 4 года назад

How do you make these videos. I was thinking to try it for my school presentation.

@asandiswashange8987 4 года назад

Thank yuou so so much, this was helpful

@akram.jaffar 4 года назад

You're so welcome!

@bornapurebeast3123 9 лет назад

Hello. I like your explanations of levers in the human body. I have one question. How would I be able to calculate the force required to move objects? Is there formula? I am curious because I am interested in figuring out stuff like how much pounds of force is required during something like a push up. I want to know how much pounds I am moving when I do a push up and what lever is being acted on. Thanks in advance, as well as to any other youtuber that would like to help me.

@MuhammadAli-ii7gp 5 лет назад

Nice explaination but we need formula of those classes and can be derived!

@silentsslayer...8149 3 года назад

this helpful to me I'm at school btw. lol

@zanmar6764 7 месяцев назад

Best explained

@akram.jaffar 7 месяцев назад

Glad you liked it

@jeffersonwright3338 8 лет назад

Thank you :)

@akram.jaffar 8 лет назад

Best wishes

@saurabhrana356 4 года назад

Hello sir🙏 Which type of lever is most effective in sports movement??

@akram.jaffar 4 года назад

Depends

@kailashMason 3 года назад

very helpful

@akram.jaffar 3 года назад

Glad to hear that

@neshkur3459 8 лет назад

Thanks :)

@jemieisola8227 10 лет назад

Watch Amazing Facts about the Human Body

@chids3302 8 лет назад

thank you

@jakeportolese4031 3 года назад

Thank You!

@akram.jaffar 3 года назад

You're welcome!

@andreavendlenepereira7200 3 года назад

Thankyou so much. ❤️

@akram.jaffar 3 года назад

Welcome!

@TimpBizkit 5 лет назад

The muscles that extend the foot are actually on a first class lever system. The toes are not the fulcrum but the load and the ankle is the fulcrum. If the soleus and gastrocnemius were attached to a ceiling hoist, it would qualify as a second class lever, but because they are attached to the, but because they are attached to the back of the tibia near the knee joint (actually the gastrocnemius is attached to the bottom of the back of the femur so plays some role in bending the leg if not countered by the quadriceps), they anchor to the moving fulcrum. It's easier to visualise this lever as pushing the floor down rather than lifting the body up. Practically the only second class lever in the body might be biting with the very back wisdom teeth, depending upon the insertion point of the massetter this could either be second class or very slightly third class or just direct in line with the muscle.

@abhaygupta9214 6 лет назад

Thanku buddy , nice video

@akram.jaffar 6 лет назад

Thank you! ru-vid.com/show-UC_jGNnK94Pbfp-LRK5w_diAcommunity?lb=Ugwx1uo_bIJfYZHaT-V4AaABCQ

@confident1614 8 лет назад

Ycan you do an arabic version

@amulekumar4961 5 лет назад

Ha bibi habibi Rafal #india

@benjamintinker4516 5 лет назад

yeet gcse pe tomorrow #gcse2019

@renukapandit8257 3 года назад

Finally got the concept lol 🙆

@nourjanaby298 6 лет назад

دكتور فراس ❤️ عرفتك من صوتك 💁🏼 شكرا على الشرح

@akram.jaffar 6 лет назад

???

@nourjanaby298 6 лет назад

Human Anatomy Education دكتور فراس انته مو ؟؟؟

@akram.jaffar 6 лет назад

+noor muh No I am not.

@MargaretImadojemu Год назад

I love this

@akram.jaffar Год назад

Thanks!

@nourjanaby298 6 лет назад

He is my doctor in my medical school 😄

@azharmehboob2460 11 месяцев назад

Tysm❤

@akram.jaffar 11 месяцев назад

Thanks!

@drbonesshow1 7 месяцев назад

The triceps is also a 1st class lever.

@nabarajbaral2063 4 года назад

Wheel and axle is also called a continuous lever, why?

@budekins542 6 лет назад

Explained in plain English.

@georgemichas3393 3 года назад

Why the body has mostly 3rd type levers?

@akram.jaffar 3 года назад

Minimum shortening of muscle results in wider range of movement.

@georgemichas3393 3 года назад

And why not 1st type levers? Can you also give an example of 3rd type levers in everyday life?

@chomperknight 3 года назад

finally a video that i can use to cheat

@DeIaynomore 5 лет назад

1 class level's mechanical advantage can be =1 as well

@anilruidasibcbadabusiness3674 8 лет назад

লিভার আমাদের সুস্থ রাখে

@damianleen 3 года назад

Te pusiste la 10 capo

@yadmariwan7511 Год назад

Dr akram are you from kurdistan

@akram.jaffar Год назад

I live in Canada after I left Iraq long ago, but I am not originally from Kurdistan with due respect to Kurds. Thanks for your interest in the channel.