Muscles

Posted on 19 Mar 2010 23:45

See the anatomy category for more articles related to human anatomy.

Forearm Extensor Muscles - Origins, Insertions, and Actions, with Video Presentation

The following is information on the extensor muscles of the forearms. These videos were produced to help students of human anatomy at Modesto Junior College study their anatomical models.

They are done with models showing the muscular structure of the arm.

The following two videos present an overview of the major flexor muscles of the forearm, which are the muscles of the posterior compartment.

Each video is followed by information on the origin, insertion, and actions of each muscle covered in the video.

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Forearm Flexor Muscles - Origins, Insertions, and Actions, with Video Presentation

These videos were produced to help students of human anatomy at Modesto Junior College study their anatomical models.

They are done with models showing the muscular structure of the arm.

The following two videos present an overview of the major flexor muscles of the forearm, which are the muscles of the anterior compartment. These muscles not only are responsible for flexion of the wrist, but are also the extrinsic muscles of the hand, responsible for much its gripping strength.

Each video is followed by information on the origin, insertion, and actions of each muscle covered in the video.







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Brachialis Muscle: Locations, Actions, and Trigger Points

The brachialis muscle is located on the front part of the upper arm, nearest the elbow. Along with the biceps brachii and the brachioradialis, it is one of the primary flexors of the elbow. It gets its name from the Greek words brachialis and brachion, pertaining to the (upper) arm. It is important not to confuse these words with the Greek brachy which means "short." Although not as large as the biceps brachii, the brachialis is a relatively large and wide muscle and these two muscles, along with the coracobrachialis, make up the anterior (front) compartment of the upper arm. Unlike the biceps brachii, which attaches to the radius, the brachialis attaches to the ulna, making it suited for flexion of the elbow only, since it can only pull on the ulna and the ulna does not rotate. However, it provides strong elbow flexion in both supination and pronation.Bibliography item doyle not found.,Bibliography item simons not found.

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What are the Main Muscles Active During the Deadlift?

See a full description of the lifting technique for the deadlift. The deadlift is actually a total body exercise. In other words, to some extent, every muscle in the body becomes involved. It would be impossible to accurately outline the contribution of every single muscle group during the deadlift, especially since this can change as the weight on the bar is increased and the lift becomes more challenging. However, comparisons can be made to another core lift, the back squat. And the main active muscles groups can be listed.

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Biceps Brachii: Location, Actions, and Trigger Points

The biceps brachii is a two-headed muscle located on the front of the arm, and makes up the largest part of its bulk. The name biceps is derived from the Greek word bi, meaning "two" and the Latin caput, meaning "head." The name brachii is a form of the Latin and Greek words brachialis and brachion, which describe something that pertains to the arm. Thus, biceps brachii means "two headed muscle of the arm." These two heads, one shorter than the other, arise from two separate origins which, although they partially combine into one large muscle, retain somewhat their separate features, both inserting together at the elbow.Bibliography item doyle not found.

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What is Adaptive Shortening?

A muscle can change it's functional resting length to adapt to the length at which the muscle is habitually used or positioned. Adaptive Shortening is muscle tightness resulting from a muscle being forced to remain in a shortened position for a prolonged period of time, being unable to lengthen due to the relaxation of the antagonist group. An example of this type of shortening is the shortening of the iliopsoas (one-joint hip flexors) in individuals who are confined to a wheelchair or who must spend most of their day sitting. Another example is the wearing of high-heeled shoes, which can cause adaptive shortening of the soleus since the foot must remain in plantar flexion. Apaptive shortening of muscles causes postural distortions which result in further imbalance between opposing pairs of muscle.

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Teres Major Muscle: Location, Actions, and Trigger Points

The teres major muscle is a small, round muscle lying along the lateral border of the scapula. It forms the inferior border of both the triangular space and quadrangular space. The muscle gets its name from its shape and size. Teres means "round" in Latin, and the term major refers to it being the larger of two muscles, the teres minor muscle lying just superior to the major. Both the teres major and minor are similar in shape, only the major is larger. It can be palpated in the trough between the lateral scapula and the latissumus dorsi, but is deeper than the lattisumus.

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Scalene Muscles: Location, Actions, Trigger Points, and Thoracic Outlet Syndrome

The scalene muscles are three paired muscles of the neck, located in the front on either side of the throat, just lateral to the sternocleidomastoid. There is an anterior scalene (scalenus anterior), a medial scalene (scalenus medius), and a posterior scalene (scalenus posterior). They derive their name from the Greek word skalenos and the later Latin scalenus meaning "uneven", similar to the scalene triangle in mathematics, which has all sides of unequal length. These muscles not only have different lengths but also considerable variety in their attachments and fiber arrangements. As you will see from the descriptions below, these muscles are in a very crowded place and are related to many important structures such as nerves and arteries that run through the neck.

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Rhomboid Major and Minor Muscles: Location, Actions, and Trigger Points

The proper names for the muscles we call the rhomboids are Rhomboideus Major and Minor or the Rhomboidei. Although two different muscles, they are very difficult to distinguish from one another and perform the same actions together. They run obliquely downward from the spine to the inner edge of the scapula, on each side of the middle back and connect the vertebra in that area to the medial border of the scapula. They are largely covered by the more superficial trapezius muscle.

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Extensor Digitorum Muscle: Location, Actions, and Trigger Points

The extensor digitorum1 muscle gets its name from the Greek and Latin ex which means "out of", and the Latin tendere, which means "to stretch". So an extensor is a muscle that stretches out or straightens out a joint. The word digitorum is from Latin, indicating the digits or fingers. Communis is Latin for "common" and it refers to a muscle which has several branches or structures.Bibliography item doyle not found.

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Splenius Capitus and Cervicis Muscles: Location, Actions, and Trigger Points

The splenius muscles are broad and thin, getting their name from the Greek word splenium, meaning bandage. Capitus comes from the Latin word for head, caput which refers to the origin of the splenius capitus on the mastoid process and adjacent occipital bone of the skull, underneath the sternocleidomastoid. Cervicus derives from the Latin word cervix which pertains to the neck, referring to the splenius cervicus having its origin on the cervical spine. Bibliography item arnold not found.,Bibliography item simons not found.

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Deltoid Muscle: Location, Actions and Trigger Points

By Eric Troy, Ground Up Strength

The deltoid muscle is a large, triangular, course, and thick muscle which gives the shoulder its shape and contour. Its name is often reported to have derived from the Greek letter Delta (Δ) but it actually derives from the Latin word deltoides which means "triangular in shape or form" and was taken from the shape of the letter delta and the word eidos (oid) meaning shape or form. The deltoid is the principal abductor of the arm at the glenohumeral (shoulder) joint and also flexes and extends the humerus. The deltoid is the largest and probably the most important muscle of the shoulder complex. Bibliography item howell not found., Bibliography item doyle not found.

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Digastric Muscle: Location, Actions and Trigger Points

The digastric is a double muscle of the throat which is located under the chin, behind and below the corner of the jaw, immediately in front of the top of the sternocleidomastoid, one for each side of the jaw and neck. It gets its name from the Greek word for "two bellies". The Greek word dia means double and gaster means belly hence digastric meaning "two-bellied".Bibliography item arnold not found. The digastric is made up of an anterior and posterior belly. The anterior belly extends from the digastric fossa of the mandible and the posterior belly extends from the mastoid notch of the temporal bone. Both bellies then insert to the body of the hyoid bone via a fibrous loop over a common intermediate tendon between the two bellies.

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Temporalis Muscle: Location, Action and Trigger Points

The temporalis muscle is a large, thin fan-shaped muscle located in the side of the skull above and in front of the ear. It is a muscle of mastication and its role is similar to the masseter, which is to elevate the mandible (lower jaw) and so close the mouth. Although the masseter is the more powerful muscle the temporalis is an important chewing muscle. It starts at the temporal bone of the skull but passes all the way down beneath zygomatic arch (cheek bone), attaching to the mandible, enabling it to assist the masseter in closing the jaw but also to retract the mandible.

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This page created 19 Mar 2010 23:45
Last updated 27 Oct 2015 19:30

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