Title: The Rotator Cuff and the Quadriceps Complex
1- The rotator cuff muscles include: The infraspinatus, supraspinatus, teres
minor and the subscapularis. These muscles act to strengthen and increase
the stability of the shoulder joint. They also act individually to move the
humerus and the upper arm.
a- In addition to strengthening the shoulder they pull the humerus into the
socket joint (glenoid fossa) increasing the contact of the bony elements.
This is the most important factor contributing to the stability of the joint
b- Injury to any of these muscles is disabling because the stability of the
humerus in the joint is lost. The other muscles of the arm lose the ability
to move the humerus correctly, resulting in the dislocation of the joint.
c- Chart
Name
Supraspinatus
Origin
Insertion
Action
Infraspinatus
Teres Minor
Subscapularis
2- The Quadriceps Complex – The quadriceps complex is a part of the thigh
muscle group, which is composed mainly of large muscles that act to move
the hip and knee joint. The muscles that effect the movement of the thigh are
among the strongest in the body
a- The quadriceps femoris is a large four-headed muscle that makes up the
bulk of the thigh and is the principal muscle of the quadriceps complex.
b- The quadriceps femoris is the strongest muscle in the body
c- It consists of four parts whose tendons combine who combine to form the
quadriceps tendon. The quadriceps tendon inserts on the top of the
patella and then continues down as the patella tendon and inserts on the
anterior tibia.
d- The quadriceps femoris acts to straighten the knee, it is an extensor that
is used in climbing, running, and jumping. It straightens the knee when
going from a sitting to a standing position.
e- Chart
Name
Rectus femoris
Origin
Insertion
Action
Vastus lateralis
Vastus medialis
Vastus
intermedius
What is the name of the prominence that the patella tendon attaches to?