8. Joints

Joint Movements

Open Question
Discuss the relative value (to body homeostasis) of immovable, slightly movable, and freely movable joints.
Open Question
Of the following actions, the one that illustrates that of a second-class lever is (a) knee extension, (b) ankle extension (plantar flexion), (c) flexion at the elbow, (d) none of these.
Open Question
Which types of movements are affected when the hamstrings are injured?
Open Question
Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

d. The joint between the two pubic bones and the intervertebral joints are examples of symphyses.
Open Question
In general, when mobility of a joint______, its stability_______.

a. increases; increases
b. decreases; decreases
c. increases; remains unchanged
d. increases; decreases
Open Question
Bone movement at a joint is described around an invisible line known as a/an:

a. synarthrosis.
b. axis.
c. sagittal plane
d.amphiarthrosis.
Open Question
Define each of the following movements or movement pairs.

a. Flexion and extension
b. Adduction and abduction
c. Rotation
d. Circumduction
e. Dorsiflexion and plantarflexion
f. Elevation and depression
Open Question
Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

e. The hip joint is less stable than the shoulder joint, but it allows more motion.
Open Question
Which of the following best describes the function of the anterior cruciate ligament?

a. It prevents posterior displacement of the tibia on the femur.
b. It prevents the tibia from moving too far laterally on the femur.
c. It prevents anterior displacement of the tibia on the femur and hyperextension.
d. It improves the fit between the femur and the tibia.
Open Question
The structure that stabilizes the shoulder joint is known as the:

a. rotator cuff.
b. radial collateral ligament.
c. posterior cruciate ligament.
d. fibular collateral ligament.
Open Question
Which factors contribute to the stability of the hip joint?
Open Question
Lauren has hurt her knee playing soccer. She explains that during the match, someone tackled her, hitting her on the lateral side of her knee. You notice during your examination that she has excessive range of motion in her knee; specifically, you are able to hyperextend her knee and anteriorly displace her tibia on her femur. Her tibia also displaces laterally on her femur. What has likely happened to her knee? Explain.
Open Question
Some individuals have an abnormally small and shallow glenoid labrum. How would this affect the stability of the shoulder joint?