Muscle Contraction Report

The muscles’ stretched starting position means that the individual sarcomeres of her muscles have less overlap

Firstly, an isometric contraction is when the length of the muscle does not change and the angle of the joint does not change. The muscle is active during this contraction but it is in a static position. An example of this is when you stop halfway when doing a squat or push-up or holding yourself in an abdominal plank position. This type of muscle work is quite easy to do, however it can result in fatigue very quickly. Furthermore, this type of muscle work can cause a sharp increase in the blood pressure in the body because blood flow is reduced. Another type of muscle contraction is the concentric muscle contraction; this occurs when a muscle shortens against a resistance, an example of this is a bicep curl. The brachialis and bicep shorten, bringing your forearm towards your upper arm. These types of contraction are also known as the positive phase of muscle

As a result of the contractions in the Muscle- Skeletal Longitudinal Section cells and the Muscle- Skeletal Cross Section cells, it allows your muscle to be able to contract in response to nerve stimuli. This means that the movements of most of these muscles are not involuntary, you can control them. Therefore, once the stimulation stops, the muscles relax.

During an eccentric contraction, the muscle lengthens under tension due to an opposing force that is greater than the force being produced by the muscle (Lindstedt et al. 2001). Eccentric contractions require little metabolic energy, however they are characterized by a high production of force (Semmler 2014). Fick observed that a lengthening muscle contraction could exert more force than a shortening muscle contraction, while Hill later observed that the body has a lower energy demand when contracting eccentrically compared to concentrically (Lindstedt et al. 2001). When the force applied is larger than the force that is created, work is done on the lengthened muscle and mechanical energy is absorbed – this is called “negative work” (Lindstedt et al. 2001). This absorbed energy can either be dissipated as heat, or it can be temporarily stored as elastic recoil potential energy for later use (Lindstedt et al. 2001).

The time point the muscle started to decrease was round about the 35 second mark. At this point there was an 85.5 percent decline in force from the maximum force at the end of the stimulation. By the time the muscle reached the fatigue stage less muscle fibers were able to contract and because less fibers contracted, the force needed to contract these fiberes were much less than that of the initial maximal force resulting in the very high percentage of decline in force.

8. What stretch resulted in the highest contraction force? What happens to the muscle at the highest stretch levels?

The six fundamental movements of Major Body Segments are flexion, extension, abduction, adduction, rotation, and circumduction. Flexion is a decrease in the angle between two body segments. Flexion occurs at the shoulder, elbow, hip, and knee joints. An example exercise is doing curls on the arm curl machine. Extension is an increase in the angle between two body segments, or the return from flexion. An example exercise is by working on the leg extension. Abduction is the movement of a body segment away from the midline. An example exercise for this body segment is a dumbbell lateral raise, spreading of the fingers or toes, or the legs moving apart on a hip abductor machine. Adduction is the movement of a body segment toward the midline, or

In task B, the rectus abdominus muscle activity doubled and the external oblique increased times four. The internal oblique muscle was more active than the external oblique in task C and D than it was in task B. This is because of the potential for rolling off the ball which caused a co-contraction of the rectus abdominus and the external oblique muscles. When all of these muscles contracted, this helped to provide stability to the body.

The bracing action or co-contraction are also referred to as global muscles, which are located toward the front of the external and internal obliques, quadratus lumborum's lateral fibers, erector spinae's lateral segments, and rectus abdominus. These muscles help to control the ability of the spine to resist bending and impact the alignment of the spine by complying and balancing two imposing forces. These assist in:

Isometric contractions is another type of contraction which occurs when there is no change in the length of the contracting muscle. This contraction takes place when carrying an something heavy in front of you as the weight is pulling the arms down the but the muscles are contracting to keep the object on the same level. Another example can be when you grip something, like a tennis racket. There is no movement taking place in the joints of the hand, but the muscles are contracting to provide a force that is enough to provide a force enough to keep a firm and steady hold on the racket. The amount of force the muscle is able to produce during an isometric contraction depends on the length of the muscle at the point contraction. Each muscle has

As muscles can only pull they must work together to as antagonistic pairs, this is where one muscle contracts and shorten (Concentric) while the other relaxes and lengthens (eccentric) in other to allow the movement to occur, this is known as an isotonic contraction. The voltotary muscles are also capable of an isometric contraction this is where the muscle/s are contacting but no movement is occurring for example in a ski sit or Rugby scum. Muscles are also able to undergo an Isokinetic contraction where by the muscles contract and shorten at a constant speed.

Agonist muscles are the main muscles responsible for isotonic contractions; as they are predominantly responsible for producing a specific movement they are also referred to as “prime movers”. Antagonist muscles control a movement and also return limbs back to the original position. If a movement is performed in reverse the antagonist and agonist muscle switch roles, therefore one muscle can be both an agonist and an antagonist depending on

A muscle contraction has 4 stages, muscle activation, muscle contraction, recharging and relaxation. For a muscle contraction to occur there must be a Neural stimulus, which is a hormone also known as adrenaline, that is released by the endocrine gland. There has to be calcium in the cells, which is a chemical element found in many foods, and there must be ATP there for energy.

Three muscle stretching techniques are frequently described in the literature: Static, Dynamic, and Pre-Contraction stretches (Figure 2). The traditional and most ...

Eccentric muscle is a contraction which increases tension on a muscle as it lengthens. It occurs when lowering weights which at that moment your muscles gives a stronger force which causes the muscles to lengthen as it contracts.