Lever systems in the human body

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Күн бұрын

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.).
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Пікірлер: 125

@fitnessmaximabdb6815 5 жыл бұрын

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

@shayadubin1844 8 жыл бұрын

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

@akram.jaffar 8 жыл бұрын

+Shaya Dubin Thank you and best wishes!

@RodneyMarquezFishingChannel 8 жыл бұрын

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

@akram.jaffar 8 жыл бұрын

+Rodney Marquez Thanks!

@justinpierzchala8494 9 жыл бұрын

Great video very helpful, thank you!

@ipdconvipack7899 9 жыл бұрын

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

@leenakar1462 4 жыл бұрын

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

@danak9594 9 жыл бұрын

This is a very illuminating video, thank you

@ChrisStaff 4 жыл бұрын

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

@shimmyology 10 жыл бұрын

Really helpful, thank you.

@jeon0169 6 жыл бұрын

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

@yousefza5551 8 жыл бұрын

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 :)

@TinqXP 6 жыл бұрын

Thank you for the video , much appreciated

@Laotzu.Goldbug 5 жыл бұрын

Very solid video, thank you Doctor Jaffar.

@njwildberger 9 жыл бұрын

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 жыл бұрын

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 жыл бұрын

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

@koreanseriessingha6070 5 жыл бұрын

Bed

@TimpBizkit 5 жыл бұрын

@@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.

@tcubaseball11 8 жыл бұрын

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

@akram.jaffar 8 жыл бұрын

+Oscar Pena You are welcome. Best wishes!

@uncannysin 3 жыл бұрын

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

@akram.jaffar 3 жыл бұрын

Glad it was helpful!

@tomvilar1753 9 жыл бұрын

Great Video! Thank you!

@user-uy8ex1uk9q 7 ай бұрын

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

@akram.jaffar 7 ай бұрын

Glad it was helpful!

@drbonesshow1 7 ай бұрын

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.

@hootanvakili9009 9 жыл бұрын

excellent explanation, great job Dr Jaffar

@antoniosantiago9503 6 жыл бұрын

Thanks for this amazing video.

@gabbyhaar4243 4 жыл бұрын

this was amazing. thank you so much!

@gajalakshmi776 5 жыл бұрын

Thank so much for your vedio I'm from tamilnadu

@subrataray5371 4 жыл бұрын

Thanks for your video 😊😊

@peybak 4 жыл бұрын

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 жыл бұрын

What was the result?

@torpacio 8 жыл бұрын

That was great. Thank you!

@michaelaworona4037 3 жыл бұрын

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

@interstellarinc 9 жыл бұрын

fab video - thanks

@asmaasaid1656 8 жыл бұрын

جزاكم الله خيرا

@Mo95793 8 жыл бұрын

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 жыл бұрын

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

@Laotzu.Goldbug 5 жыл бұрын

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.

@Waliul_The_Wall-E 6 жыл бұрын

that was very helpful

@mohammedhjmtm7593 6 жыл бұрын

Thank you very much ❤!!

@jaykrishnatirupati7311 5 жыл бұрын

best classification ever

@khushboodalal3587 10 жыл бұрын

helpful, thanks!

@jamesjalali6338 7 жыл бұрын

Thank you, come again

@MaximFit 10 жыл бұрын

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 жыл бұрын

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.

@jzwillows Жыл бұрын

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.

@bornapurebeast3123 9 жыл бұрын

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 жыл бұрын

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

@danyadanya1079 8 жыл бұрын

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

@akram.jaffar 8 жыл бұрын

+Tabark Faiz Best wishes

@danyadanya1079 8 жыл бұрын

+Human Anatomy Education ur welcome 💐💐

@dheerajbaji8990 8 жыл бұрын

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

@akram.jaffar 8 жыл бұрын

+Baji Dheeraj You are welcome!

@amansaiyad7177 5 жыл бұрын

Best video ever

@asandiswashange8987 4 жыл бұрын

Thank yuou so so much, this was helpful

@akram.jaffar 4 жыл бұрын

You're so welcome!

@p.z.8355 4 жыл бұрын

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

@p.z.8355 4 жыл бұрын

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

@osamaselim2607 4 жыл бұрын

الله يباركلك :)

@jakeportolese4031 3 жыл бұрын

Thank You!

@akram.jaffar 3 жыл бұрын

You're welcome!

@afjalurrahmanradil6130 3 жыл бұрын

Thank you sir.......👌

@akram.jaffar 3 жыл бұрын

Most welcome

@1983duka 10 жыл бұрын

good information...

@silentsslayer...8149 3 жыл бұрын

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

@andreavendlenepereira7200 3 жыл бұрын

Thankyou so much. ❤️

@akram.jaffar 3 жыл бұрын

Welcome!

@ajeetkumartiwari9264 10 жыл бұрын

Helpful thank u

@AlabasterPeacock 2 жыл бұрын

Good explanation, thank you

@akram.jaffar 2 жыл бұрын

You are welcome!

@anikatultul7291 6 жыл бұрын

it was so helpful ^_^

@prachisharma7128 4 жыл бұрын

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

@nourjanaby298 6 жыл бұрын

He is my doctor in my medical school 😄

@neshkur3459 8 жыл бұрын

Thanks :)

@jeffersonwright3338 7 жыл бұрын

Thank you :)

@akram.jaffar 7 жыл бұрын

Best wishes

@yanling60 3 жыл бұрын

Awesome vid

@akram.jaffar 3 жыл бұрын

Thank you!

@jemieisola8227 10 жыл бұрын

Watch Amazing Facts about the Human Body

@saurabhrana356 3 жыл бұрын

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

@akram.jaffar 3 жыл бұрын

Depends

@akram.jaffar 10 жыл бұрын

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

@chids3302 8 жыл бұрын

thank you

@kailashMason 3 жыл бұрын

very helpful

@akram.jaffar 3 жыл бұрын

Glad to hear that

@TimpBizkit 5 жыл бұрын

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.

@zanmar6764 6 ай бұрын

Best explained

@akram.jaffar 6 ай бұрын

Glad you liked it

@MargaretImadojemu 11 ай бұрын

I love this

@akram.jaffar 11 ай бұрын

Thanks!

@abhaygupta9214 6 жыл бұрын

Thanku buddy , nice video

@akram.jaffar 6 жыл бұрын

Thank you! kzfaq.info/love/_jGNnK94Pbfp-LRK5w_diAcommunity?lb=Ugwx1uo_bIJfYZHaT-V4AaABCQ

@benjamintinker4516 5 жыл бұрын

yeet gcse pe tomorrow #gcse2019

@confident1614 8 жыл бұрын

Ycan you do an arabic version

@amulekumar4961 5 жыл бұрын

Ha bibi habibi Rafal #india

@renukapandit8257 3 жыл бұрын

Finally got the concept lol 🙆

@azharmehboob2460 10 ай бұрын

Tysm❤

@akram.jaffar 10 ай бұрын

Thanks!

@nourjanaby298 6 жыл бұрын

دكتور فراس ❤️ عرفتك من صوتك 💁🏼 شكرا على الشرح

@akram.jaffar 6 жыл бұрын

???

@nourjanaby298 6 жыл бұрын

Human Anatomy Education دكتور فراس انته مو ؟؟؟

@akram.jaffar 6 жыл бұрын

+noor muh No I am not.

@nabarajbaral2063 4 жыл бұрын

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

@drbonesshow1 7 ай бұрын

The triceps is also a 1st class lever.

@georgemichas3393 3 жыл бұрын

Why the body has mostly 3rd type levers?

@akram.jaffar 3 жыл бұрын

Minimum shortening of muscle results in wider range of movement.

@georgemichas3393 3 жыл бұрын

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

@DeIaynomore 5 жыл бұрын

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

@budekins542 6 жыл бұрын

Explained in plain English.

@chomperknight 3 жыл бұрын

finally a video that i can use to cheat

@damianleen 3 жыл бұрын

Te pusiste la 10 capo

@anilruidasibcbadabusiness3674 8 жыл бұрын

লিভার আমাদের সুস্থ রাখে

@yadmariwan7511 Жыл бұрын

Dr akram are you from kurdistan

@akram.jaffar Жыл бұрын

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.