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.