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Strength


A display of "strength" (e.g lifting a weight) is a result of three factors that overlap; Physiological strength (muscle size, cross sectional area, available crossbridging, responses to training), neurological strength (how strong or weak is the signal that tells the muscle to contract), and mechanical strength (muscle's force angle on the lever, moment arm length, joint capabilities).

The 'strongest' human muscle


Since three factors affect muscular strength simultaneously and muscles never work individually, it is unrealistic to compare strength in individual muscles, and state that one is the "strongest". Accordingly, no one muscle can be named 'the strongest', but below are several muscles whose strength is noteworthy for different reasons.

  • In ordinary parlance, muscular "strength" usually refers to the ability to exert a force on an external object—for example, lifting a weight. By this definition, the masseter or jaw muscle is the strongest. The 1992 Guinness Book of Records records the achievement of a bite strength of 4337 N (975 lbf) for 2 seconds. What distinguishes the masseter is not anything special about the muscle itself, but its advantage in working against a much shorter lever arm than other muscles.

  • If "strength" refers to the force exerted by the muscle itself, e.g., on the place where it inserts into a bone, then the strongest muscles are those with the largest cross-sectional area. This is because the tension exerted by an individual skeletal muscle fiber does not vary much. Each fiber can exert a force on the order of 0.3 micronewton. By this definition, the strongest muscle of the body is usually said to be the quadriceps femoris or the gluteus maximus.

  • Again taking strength to mean only "force" (in the physicist's sense, and as contrasted with "energy" or "power"), then a shorter muscle will be stronger "pound for pound" (i.e., by weight) than a longer muscle. The uterus may be the strongest muscle by weight in the human body. At the time when an infant is delivered, the human uterus weighs about 1.1 kg (40 oz). During childbirth, the uterus exerts 100 to 400 N (25 to 100 lbf) of downward force with each contraction.

  • The external muscles of the eye are conspicuously large and strong in relation to the small size and weight of the eyeball. It is frequently said that they are "the strongest muscles for the job they have to do" and are sometimes claimed to be "100 times stronger than they need to be." However, eye movements (particularly saccades used on facial scanning and reading) do require high speed movements, and eye muscles are 'exercised' nightly during Rapid eye movement.

  • The unexplained statement that "the tongue is the strongest muscle in the body" appears frequently in lists of surprising facts, but it is difficult to find any definition of "strength" that would make this statement true. Note that the tongue consists of sixteen muscles, not one.

  • The heart has a claim to being the muscle that performs the largest quantity of physical work in the course of a lifetime. Estimates of the power output of the human heart range from 1 to 5 watts. This is much less than the maximum power output of other muscles; for example, the quadriceps can produce over 100 watts, but only for a few minutes. The heart does its work continuously over an entire lifetime without pause, and thus does "outwork" other muscles. An output of one watt continuously for seventy years yields a total work output of two to three gigajoules.


Main Muscles worked by a bodybuildertriceps_brachii.png

Triceps

The triceps brachii muscle is a large three-headed skeletal muscle found in humans. It runs along the back of the upper arm.

The triceps brachii muscle is often simply called the triceps. However, the term triceps (Latin for "three heads") can mean any skeletal muscle having three origins.

Origin and insertion

The three heads have the following names and insertions:



  • The "Long head": infraglenoid tubercle of the scapula

  • The "Lateral head": posterior shaft of the humerus, lateral and superior to the radial (spiral) groove.

  • The "Medial head": posterior shaft of the humerus, medial and inferior to the radial (spiral) groove.

The fibres converge to a single tendon to insert onto the olecranon process of the ulna.

Exercises that build the triceps

The triceps account for approximately 60 percent of the upper arm's muscle mass, but people who exercise the arms with weights often neglect this group of muscles in favour of the biceps brachii. Because i think somebody who practice bodybuilding in the half for « fun » mean that biceps are more bigger than triceps, but that is wrong.

The triceps can be worked through either isolation elbow extension movements, contract statically to keep the arm straightened against resistance, or compound pressing movements

Isolation movements include cable push downs, skull crushers and arm extensions behind the back.

Static contraction movements are pullovers, straight-arm pulldowns, and bent over lateral raises which are also used to build the rear deltoids and latissimus dorsi.

Examples of pressing movements are press ups, bench presses (level, incline or decline), military presses and dips. Using a closer grip stabilizes the arm allowing more weight to be used, so the triceps can be worked harder without being limited by the strength of the pectorals or shoulders.

That is Dips, my favorite dips’s exercise.dips.jpg

For more difficulty i add weight with a belt.

My personnal record are 4 repetitions with 80kg added

with a belt.

Elbow extension is important to many athletic activities. As biceps are often worked more for aesthetic purposes, this is usually a mistake for fitness training. While it is important to maintain a balance between the biceps and triceps for postural & effective movement purposes, what the balance should be and how to measure it is a conflicted area. Pushing and pulling movements on the same plane are often used to measure this ratio.



Biceps

In human anatomy, the biceps brachii is a muscle located on the upper arm. The biceps has several functions, the most important simply being to flex the elbow and to rotate the forearm.

The biceps brachii is arguably the best known muscle, as it lies fairly superficially, and is often well-defined even in non-athletes. The muscle is popular amongst bodybuilders, and can grow quite large through weight training.

Terminology

The term biceps brachii is a Latin phrase meaning "two heads of the arm", in reference to the fact that the muscle consists of two bundles each with its own origin but with a common insertion point near the elbow.

Note that the word biceps is both singular and plural: the form bicep, although common, is incorrect. (The Latin plural bicipites is considered pedantic and rarely used.)

Anatomy

Proximally, the short head of the biceps attaches to the coracoid process of the scapula. The tendon of the long head passes into the joint capsule at the head of the humerus, and attaches on the scapula at the supraglenoid tubercle.

Distally, biceps attaches to the radial tuberosity, and because this bone can rotate, the biceps also supinates the forearm. The biceps also connects with the fascia of the medial side of the arm, at the bicipital aponeurosis.

Two additional muscles lie underneath the biceps brachii. These are the coracobrachialis muscle, which like the biceps attaches to the coracoid process of the scapula, and the brachialis muscle which connects to the ulna and the humerus.

Functions

The biceps is tri-articulate, meaning that it works across three joints. The most important of these functions are to flex the elbow and to supinate the forearm.

These joints and the associated actions are as follows:


  • Shoulder joint (glenohumeral joint) - flexion (bringing arm upward by a forward motion)

  • Elbow joint - flexion. Arguably the most functional of the biceps' functions is elbow flexion. This refers to bending the forearm toward the upper arm, resulting in a decrease of angle. More commonly, this is known as the action performed in a biceps curl. The brachialis muscle and brachioradialis muscle are known to aid in this action as well.

  • Proximal radioulnar joint - supination of the forearm. One of the main functions of the biceps is to, along with the supinator muscle, aid in supination of the forearm, which refers to the allowing the forearm, and subsequently, the palm, to be rotated or moved toward the anatomical position, the resulting hand position not dissimilar to that of the biceps curl. This has also been achieved through the use of functional electrical stimulation as a means of emulating electrical impulses used within the synapses, and allow slight movement within those with paralysis. It has also been proven through several tests into muscle group stimulation, that a supinated grip allows for close and normal-grip bench press exercises to have a much more profound effect on the biceps brachii and the clavicular portion of the pectoralis major.

Training

There are many forms of resisted elbow flexion, better known as a curling motion, which exercise the biceps.

Some common iterations include:


  • The barbell curl

  • The wide barbell curl

  • The straight bar curl

  • The dumbbell curl

  • The incline dumbbell curl

  • The seated dumbbell curl

  • The cable curl

  • curl_biceps_1.bmpCurl biceps

Working out the upper back muscles through rowing and pulling motions will also incorporate some Biceps Brachii due to great amounts of necessary elbow flexion. However, simultaneous extension of the glenohumeral joint will result in some lengthening of the biceps, thus weakening the biceps' contraction and deferring a great deal of the elbow flexion work to the brachialis and brachioradialis. The role of the biceps during such motions is what is known as a dynamic stabilizer.

Quadricepsillu_lower_extremity_muscles.jpg

The quadriceps femoris (quadriceps extensor, or quads) includes the four prevailing muscles on the front of the thigh. It is the great extensor muscle of the knee, forming a large fleshy mass which covers the front and sides of the femur.

It is subdivided into separate portions, which have received distinctive names.


  • Rectus femoris occupies the middle of the thigh, covering most of the other three quadriceps muscles. It originates on the ilium. It is named from its straight course.



  • The other three lie deep to rectus femoris and originate from the body of the femur, which they cover from the trochanters to the condyles:

    • Vastus lateralis is on the lateral side of the femur.

    • Vastus medialis is on the medial side of the femur.

    • Vastus intermedius lies between vastus lateralus and vastus medialis on the front of the femur.

All four parts of the quadriceps muscle attach to the patella via the quadriceps tendon.

Actions

All four quadriceps are powerful extensors of the knee joint. They are crucial in walking, running, jumping and squatting. Because rectus femoris attaches to the ilium, it is also a flexor of the hip. This action is also crucial to walking or running as it swings the leg forward into the ensuing step.

Training

There are a lot of exercises to train quadriceps. Mosts uses are the press, legs extensions, hack squat, split, but the king exercise for quadriceps and which affraid a lot of bodybuilder is THE SQUAT (below). Because when you train our quadriceps it’s very tiring and the squat need our physical ressources.



vlcsnap-1168755.png

This is a photo of Ronnie Coleman, 8 times Mr Olympia, when he practice a squat.

Harmstring

In human anatomy, a hamstring refers to one of the tendons that makes up the borders of the space behind the knee. In modern anatomical contexts, however, they usually refer to the tendons of the semitendinosus, the semimembranosus, and the biceps femoris. In quadrupeds, it refers to the single large tendon found behind the knee or comparable area.

As shown in the diagram, the human hamstring occupies the posterior of the body of the femur.


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