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Fulcrums

Hello fellow educators....I want to pick your brains! I am having a hard time finding a simple way of teaching fulcrums to my students. How do you do it? Is there a text or website that lays this out in simple terms ? Most of the massage texts only briefly cover it, and not very well....or at least not well enough to get most of the students to understand the concept. I use the see-saw analogy, and some get that...but most don't. I would be glad to exchange ideas about any other anatomy subject as well.

Replies to This Discussion

Permalink Reply by Nate Ewert on July 23, 2009 at 12:20pm

I think the important thing in dealing with levers and fulcrums is being able to show how they work in the body. With a 1st class lever, which is the see saw analogy, you could also use scissors as an example, we see that in flexion and extension in the head. For extension, the force comes from the suboccipitals, the fulcrum is next in line at the atlanto-occipital joint, and the resistance becomes the wieght of the head in front of the fulcrum.

When looking at 2nd class levers, like a wheel barrel, the fulcrum is on one end, the resistance is in the middle and the force is on the other end. In the body we can see this in plantar flexion when standing. The ball of the foot is the fulcrum, the wieght of the body is the resistance and the calf muscle provides the force.

But the most prevalent in the body is the 3rd class lever. An example would be tweezers. The resistance is on one end, the force in the middle and the fulcrum is on the other end. Sofor this let's take a look at elbow flexion. The resistance would be the wieght of the hand and forearm, the force is created by the biceps brachii and brachialis, which insert on the foream distal to the elbow joint, which would leave the fulcrum being the elbow joint itself, proximal to the insertions of the two muscles.

I hope this helps, I couldn't find any good visual aids to upload. I usually draw these (very poorly) on the board.

Permalink Reply by Noel Norwick on July 23, 2009 at 12:20pm

Re Fulcrum: a support or the point thereon on which a lever turns. You may try printing out and discussing the following webpage: http://en.wikipedia.org/wiki/Lever

Permalink Reply by Terri Sloan, PhD, DD, NCMT, LMT on July 23, 2009 at 12:23pm

Awsome! Thanks....I have printed this out for future use...OK?

Nate Ewert said:

I think the important thing in dealing with levers and fulcrums is being able to show how they work in the body. With a 1st class lever, which is the see saw analogy, you could also use scissors as an example, we see that in flexion and extension in the head. For extension, the force comes from the suboccipitals, the fulcrum is next in line at the atlanto-occipital joint, and the resistance becomes the wieght of the head in front of the fulcrum.

When looking at 2nd class levers, like a wheel barrel, the fulcrum is on one end, the resistance is in the middle and the force is on the other end. In the body we can see this in plantar flexion when standing. The ball of the foot is the fulcrum, the wieght of the body is the resistance and the calf muscle provides the force.

But the most prevalent in the body is the 3rd class lever. An example would be tweezers. The resistance is on one end, the force in the middle and the fulcrum is on the other end. Sofor this let's take a look at elbow flexion. The resistance would be the wieght of the hand and forearm, the force is created by the biceps brachii and brachialis, which insert on the foream distal to the elbow joint, which would leave the fulcrum being the elbow joint itself, proximal to the insertions of the two muscles.

I hope this helps, I couldn't find any good visual aids to upload. I usually draw these (very poorly) on the board.

Permalink Reply by Nate Ewert on July 23, 2009 at 12:27pm

Use it all you can!! Those were all my own words so no copyright infringement here.

Permalink Reply by Terri Sloan, PhD, DD, NCMT, LMT on July 23, 2009 at 12:28pm

Duh!! Wikipedia ! I should have checked that out already !! THANKS

Noel Norwick said:

Re Fulcrum: a support or the point thereon on which a lever turns. You may try printing out and discussing the following webpage: http://en.wikipedia.org/wiki/Lever