How is the action of the SCM unique, as compared to other neck muscles?
The anterior muscles of the neck tend to flex the head and neck, while the posterior muscles tend to extend the head and neck.
The unique diagonal position of the SCM on tbe side of the neck allows it to flex the neck and extend the head.
How do the supraspinous, deltoid and trapezius work together to abduct the arm over the head?
The supraspinatus abducts the arm about 15 degrees.
The deltoid abducts the arm to 90 degrees.
The trapezius upwardly rotates the scapula to bring the humerus to 180 degrees.
Name 3 muscles that attach to the coracoid process of the scapula. Which one is primarly responsible for holding the axillary border of the scapula against the ribs?
Pec minor, short head of the biceps, coracobrachialis.
the pec minor ris primarly responsible for holding the axillary border of the scapula against the ribs.
"Panama City Beach"
Name 3 muscles that attach to the head of the fibula.
Biceps femoris (pulls up), peroneus longus and soleus (pull down)
The anterior forearm muscles...
...flex the wrist and fingers.
The superficial muscles originates on the medial epicondyles of the humerus, by way of a tendon called the common flexor tendon. Inflammation of this tendon is called medial epicondylitis, commonly known as the golfer's elbow.
The posterior forearm muscles..
...The posterior forearm muscles extend wrist and fingers. The superficial muscles originate on or around the lateral epicondyles of the humerus, by way of a tendon called the common extensor tendon.
Inflammation of this tendon is called lateral epicondylitis, commonly known as tennis elbow.
What is the pes anserinus? Name the muscles that form the pes anserinus. How does it stabilize the knees and pelvis?
The pes anserinus is the point of insertion of the sartorius, gracilis and semitendinosus on the medial proximal shaft of fibia.
The pes anserinus offers firm support to the medial side of the knee
Their respective points of origin on the pelvis form a "tripod" which helps stablilize the pelvis
In an Isotonic contracion, a visible movement is produced, during which the tension within the muscles remains fairly constant.
"Visible movement produced, tension within muscle remains fairly constant."
In an isometric contraction, the overal length of the muscle doesn't change and tension within the muscle increases greatly.
"Length doesn't change and tension increases greatly"
A concentric contraction is the same as an isotonic contraction. In other words, the muscle contracts and the origin and insertion move toward each other, hence the name "concentric", thich means toward the center.
"Muscle contracts and origin and insertion move towards eachother"
An eccentric contraction is one in which the muscle is forced to lengthen, even though its fibers are "trying" to contract.
"Muscle is forced to lengthen but fibers are trying to contract"