How should this website be read?

The most recent posts on the blog is the one at the top of the page (e.g.: this post being read right now). Because of this, the first post to be read is the one at the bottom of the page (Muscular Contraction). This will aid not only in the comprehension of the methods used to carry out the experiment but will also allow you, the reader, to understand the development of the ideas in chronological order.

To make your reading easier, below is the order in which the posts must be read.

1)How should this website be read? (Yes, this post being read now)
2)Muscular Contraction
3)What limits and enhances muscular contraction?
4)How will the measurements be made?
5)So where's the Chemistry in all this?

All information in the website was extracted from:

Biology for the IB Diploma Study Guide
Physics for the IB Diploma Study Guide
Chemistry for the IB Diploma Study Guide
The Encyclopedia of Bodybuilding by Arnold Schwarzenegger
click4biology.info
bodybuilding.com
wikipedia.org

All content was written by Charles Echols Spragins III, Julian Pascal Saadi, Henrique Luz, Stephanie Whyte, Ana Clara Biolchini and Ana Beatriz Valladares.
Edited by Charles E. Spragins III

So where’s the chemistry in all this?

We used our collective knowledge in chemistry to effectively choose the correct springs. Springs are usually made of a metal as they are the strongest and can be used for a variety of things; such as trampolines, slinkies and vehicle suspensions. But in our project, we decided to use them to measure in newtons, the force (and hence an approximate of the strength) that a certain muscle could produce (e.g. Biceps). The springs we have are both made of hardened steel. This form of steel is made by rapidly cooling the high carbon steel (quenching) and then by heating it (tempering) to produce Martensite (final form of the steel – hardened steel). Although hardened steel seems like it would be too “strong” to stretch, during the fabrication, the steel is only tempered and quenched for a certain amount of time to obtain the exact atomic constitution of the metal.

If you were wondering why we didn’t choose a different material for our spring, the answer isn’t complicated. In our situation, this one was the best choice; it’s strong, was cheap and looks good. We needed to make sure it wouldn’t either become permanently damaged when unbearable force is applied or lose its elasticity (Hooke’s Law). And so, depending on the person, we chose to use two springs, both of the same chemical material, but of different lengths and appearance. Our first spring is designed for the stronger experimenters (this spring has a shorter length, a larger diameter and a larger circumference). The second spring is destined to the less physically apt student (with a longer length, smaller circumference and a smaller diameter). Although the chemical properties are the same in both cases, the physical properties differ, and that’s what makes a difference. The fact that one of them is longer and has a smaller diameter will make it easier to pull it. The same explanation goes for the other spring.

How will the measurements be made?

Newton’s Third Law:

This law states that if there are two bodies (body A and body B), and body A exerts a force on body B, then body B exerts an equal and opposite force on body A. This can also be called the law of reciprocal action. So, if you pull the spring, the force you pull with will be equal to the force of the spring pulling you.

Hooke’s Law:

Hooke's law is the basic theory used in our project. It is an approximation that states that the extension of a spring is in direct proportion to the load added to it as long as this load does not exceed the elastic limit. The elastic limit is the maximum amount of force you can exert on the object before it is permanently physically deformed.

The formula for Hooke’s law is F=kx, where F is the restoring force exerted by the material, x is the displacement of the end of the spring from its equilibrium (starting) position and k is the spring constant.

Both these laws apply to our project. Hookes law helps explain that depending on how hard/how much force you use to pull the spring, will influence the extension of the spring. In simpler terms, the harder you pull on the spring, the more the spring will extend. Newtons third law applies, because the amount of force you apply on the spring, will then be pulled on you by the spring itself.

Two springs will be used in the experiment. The first graph accounts for the thinner spring and the second accounts for the thicker one. From these graphs, we will be able to calculate the force exerted by the person by just reading it from the graphs. If a person can easily exert 60N on the thinner spring, they will attempt to extend more on the thicker one.

What Limits and Enhances Muscular Contraction?

Limiting Factors:
1.The process of contracting a muscle involves the process of oxidation-in effect, a form of burning, which is why we say you "burn calories" (create heat by the release of energy usually stored as fat) when you exercise. Oxidation requires both a source of fuel, which in the muscles is ATP, and oxygen. Whenever ATP or oxygen is in too short supply, the muscle fibers can't contract until they are replenished as you rest and recover.

2.Another limiting factor is the buildup of waste products that result from the burning of calories due to the muscular contraction. The burning sensation felt in a muscle as you continue to carry out repetitions of an exercise is due to the accumulation of lactic acid in the muscles used. When you stop to rest, the body removes the lactic acid from the area and you are able to do more repetitions.


Enhancing Factors:

1. Increase in amount of ATP available for muscles. This can be achieved by using a nutritional supplement called creatine phosphate. The way creatine works is: it transports the phosphate required in the conversion of ADP (Adenosine Diphosphate) to ATP (Adenosine Triphosphate). ATP provides the muscle with the energy needed for it to contract. Muscles have only a limited supply of ATP and once it is used up, the body has to find ways to convert the useless ADP back to ATP. The fastest way this reaction happens in the body is using the phosphate from creatine phosphate.



2.Continuously training your muscles by lifting weights will gradually lead to muscle growth, thus enhancing muscular contraction . When muscles contract continuousl times to move a heavy load, the muscle fibers will tear. If a sufficient amount of protein is available, your body will naturally overcompensate for the muscle fibers which were broken down during the workout. Overcompensating means regenerating the already existent fibers and creating new ones.This overcompensation is what causes muscles to become bigger, consequently making them stronger

Muscular Contraction

When a spring is extended by a person, the muscles in the body used to extend it contract. The muscles being used will depend on how the body is positioned in relation to the spring. The muscles used to lift weights, exerting forces and create movement in our body are called skeletal muscle tissues. This is because they are attached by tendons to the bones of the skeleton and allow the skeleton to move. Skeletal muscle is also known as voluntary muscle, as its contraction is controlled, as opposed to cardiac muscle, a muscular tissue which its contraction is involuntary.
To fully comprehend the remainder of this study, a thorough knowledge of the anatomical chart of muscles must be developed. The diagram below shows a well developed muscular physique in which all muscles are clearly visible.






































The simplest way to lift a weight from the ground at a standing position is by contracting the bicep with the aid of the forearm flexors carrying out a movement commonly known as the bicep curl.. This is a common weightlifting exercise. Every exercise has a correct form in which it should be carried out. This form should be followed for two main reasons:

1. Prevent injuries.
2. Work out target area which the exercise is designed to.
   

As we are not carrying this experiment for muscle growth and development, reason number 2 does not seem to be very important, but it is. This is because we are considering testing not only the strength of the bicep but also the strength of other muscles such as the triceps, deltoids and pectorals. When the form of the exercise is not followed, we refer to the deviated movement as cheating. When performing bicep curls the easiest way to cheat is by elevating your shoulders in addition to curling the arm, bringing your wrists toward your body. . We want to measure the strength of the bicep alone; therefore the form must be followed to keep accurate results. When we carry out the experiment we will make sure the correct form is used.

Contracting the Bicep

The biceps brachii is a two-headed muscle with point of origin under the
deltoid and point of insertion below the elbow.
Its basic function is to lift and curl the arm and to pronate (twist downward)
the wrist.

Anatomy of a bicep:

As said previously, the biceps is made up of two heads. This mean the muscle is divided in two segments. The image below shows this clearly

The two heads are only visible on extremely developed muscles on bodies with low body fat percentages, to show clear muscular definition. Both the inner and the outter heads are visible.

The correct form to isolate the biceps performing a bicep curl is shown in the diagrams below:

Below is the incorrect form, which should be avoided:

Below is an example of a well performed bicep curl:

Contracting the Tricep

The triceps brachii, a three-headed muscle, also attaching under the deltoid and below the elbow. It is antagonistic to the bicep because when one contracts and is stressed uppon, the other stretches and relaxes.
Its basic function is to straighten the arm and supinate (twist upward) the wrist.

Anatomy of a tricep
As said previously, the tricep is made up of three heads. This mean the muscle is divided into three segments. The image below shows this clearly.
As the tricep is a larger muscle than the bicep it is easier to see its muscular definition without necessarily having extremely low body fat percentages.

Its shape is similar to that of a horse-shoe

The exercise chosen to measure tricep strength is called the tricep kickback. When performed correctly, this exercise is very efficient at targetting all three tricep heads. Below is a foto of a very well performed tricep kickback extension.


The reason why this specific exercise was chosen is because it is very hard to cheat at. But yet again, we will make sure that when this exercise is done for our measurements, we will make sure that the form is followed correctly.

Group 4 Science Project: Methods & Measurements on Pulling a Spring