Intro/Knee Joint Overview LS1/15

[Animation (2-3 seconds): For this and all future opening screens, replace existing video with brief flash animations of Shari's blue bones images (or a still image, if you prefer). Current opening videos are moved to more appropriate places in units]

In this unit, you will explore the unique structural features that allow the knee both its range of motion and its stability....As you are seated in a chair with your feet flat on the floor, your leg is in the flexed position. Extend your leg (kick it forward). Now stand up and put all your weight on one leg. You have used your own body to demonstrate that the knee joint is freely movable, yet it also is capable bearing substantial weight.

***We will need lab's decision about the opening graphics to rewrite text appropriately.

By the end of this unit, you should be able to:

-Define a joint.
-Identify and the locate 3 joints of the knee.
-Develop a familiarity with the joint nomenclature system.

Ovrvw1.0

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Notes: Animation plays as soon as screen is opened. Once it has ended, final image from animation remains.

***The learning objective for this first screen is to to catch and focus students' attention (quickly and briefly), and get them excited about what's to come. Make these opening images *super brief* and appropriate to unit content. For this unit, an animation that shows dynamic action of joint is needed.

Bullet icon (small dot?) to go in front of learning objectives (instead of number)

In this and future units, light blue text links to curriculum glossary.

Intro/Knee Joint Overview LS1/15

delete screen; incorporate text into first screen

Intro/Knee Joint Overview LS1/15

Palpate (feel) your own knee, moving your fingertips around the surface. Notice that the anterior aspect of the knee is hard and bony while the posterior aspect is soft and squishy. Now visually examine the external surface of the knee on screen, looking for similar bumps and grooves.

[Graphic: Explore the anatomy button]

What anatomic structures create the differences you palpate around the knee? We can begin to answer this question by peeling away tissues from superficial to deep.

[Graphic: Explore the anatomy button]

Notice the veins and nerves that run beneath the skin and the superficial fasciae layers.

Just beneath (deep to) these superficial vessels is a very thick and tough fascia, analogous to an elastic knee brace both in structure and function. Pull the top part of the knee (anatomists? correct anatomical terms?) towards you to view the fascia layer.

[Graphic: Explore the anatomy button]

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First IAA: Delete beginning of existing IAA. Keep the knee with skin and spin.

Second IAA: As image rotates, slowly peel skin away to fascia level; should appear as if skin is dissolving or melting off. See corresponding text for specifics on view.

Intro/Knee Joint Overview LS1/15

Removal of the muscles, nerves, and arteries reveals the basic framework of the knee. Ligaments (rope-like structures running from bone to bone) help support and stabilize the bones that come together to form the knee joint. Notice how the ligaments look different from the muscles and bones you examined earlier.]

[Graphic: Explore the anatomy button]

And finally, removing the knee joints ligaments reveals the four bones of the knee.

[Graphic: Explore the anatomy button]

First IAA: Begin IAA by "melting" fascia layer off to reveal next layer below, then rotate (as you have done) showing muscles and tendons layer. Pause on back of knee (with muscles and tendons showing).

Rotate again and melt off muscles, nerves and arteries to reveal: the joint capsule, and extracapsular ligaments, patellar ligament, fibular (lateral) collateral, tibial (medial) collateral, oblique popliteal ligament, and arcuate ligament

Second IAA: Melt away ligaments, bare bones left

Intro/Knee Joint Overview LS1/15

A common misconception is that the knee is a single joint. However, the four bones that meet at the knee form three different joints.

To identify these joints, we must first define the articulating surfaces of the bones of the knee. Explore the anatomy and notice each area of articulation: the femoral articulating surface, the patellar articulating surface, and the tibial articulating surface.

[Graphic: Explore the anatomy button]

By definition, a joint occurs where two or more bones meet--that is, where two articulating surfaces of a bone come into direct contact with one another.

Keep this definition in mind as you observe the knee in motion and watch where two areas of articulation meet--specifically, where the femoral articulating surface articulates with the patellar articulating surface. Note that the precise definition of this joint (the patellofemoral joint) changes as the knee flexes and extends.

[Graphic: Explore the anatomy button]

There are also two joints (points of articulation) between the femoral articulating surface and the tibial articulating surface. Explore the anatomy and identify these joints (the lateral tibiofemoral and medial tibiofemoral joints). You have three tries to identify each joint; use the two xrays below if you need a clue in identifying these joints.

[Graphic: Explore the anatomy button]

[Graphic: Need to select xrays that clearly show actual points of articulation for the tibiofemoral joints. Anatomists to define.]

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2 IAA's

First IAA: Image of 4 bones rotates and separately highlights each articulating surface, one at a time. The three separate colors of these highlights should match the corresponding text (femoral articulating surface, patellar articulating surface, tibial articulating surface).

2nd IAA: One rotation, bones flex and extend. Specific point of contact of patellofemoral joint (anatomists to define) is highlighted to match text color. Point changes with movement in knee.

3rd IAA: Best views of rotating bones to identify tibiofemoral joints (anatomists to define.)

Notes: For this and all future text that is highlighted in corresponding IAA's, structure name in text matches structure color in IAA.

Notes: In final activity, when students click on structure in IAA, structure is highlighted and specific structure name appears in text field. Students have three tries, then structure is automatically highlighted.

Intro/Knee Joint Overview LS1/15

To assist your recall of the names of the three joints of the knee, remember that joints are named for the bones that unite to form them.

[Graphic showing arrows and ABCs for three joints (anatomists to identify views),bones are labeled.]

Based on the names of the bones, properly identify the three joints of the knee.

Patellofemoral joint: A B C

Lateral tibiofemoral joint: A B C

Medial tibiofemoral joint; A B C

[Graphic: Clear response.]

[Graphic: Submit response.]

Ovrw5.0

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Notes: For this and all future multiple choice questions, students are provided with click boxes for each letter response. Once they are ready to submit responses, they click on Submit response graphic which records response. Instructors can then later track participation of each student. Clear responses button clears responses if students want to change mind before submitting.

Intro/Knee Joint Overview LS1/15

Like all articulations, joints A, B and C are named for the bony processes that unite to form them. Hence, the patellofemoral joint is located where the patella articulates with the femur and the medial tibiofemoral joint and the lateral tibiofemoral joint are located where the tibia articulates with the femur.

[Graphic showing three joints with labels.]

Ovrw6.0

Intro/Knee Joint Overview LS1/15

The three joints of the knee are the patellofemoral joint and the two tibiofemoral joints (medial and lateral).

The patellofemoral joint is located between the femur and the patella, a bone which lies anterior to the femur. This joint serves to increase the power of a large anterior muscle, the quadriceps femoris.

[Graphic: Explore the anatomy button]

The tibiofemoral joints (medial tibiofemoral and lateral tibiofemoral) are formed between the two large condyles (knobby projections ) of the femur (thigh bone) and the plateau like area of the tibia (shin bone). The shape of the bones forming the tibiofemoral joints allows you to flex and extend your knee.

[Graphic: Explore the anatomy button]

Ovrw7.0

Text would be enhanced by two IAA's.

Specifically, the first IAA would show the pf joint from some interesting angles, then add the quad fem muscle and some joint movement. Then the second IAA would show the areas described in the text and the flex and extend movement described.

Notes: structure names in text matches highlighted structure colors in IAA.

Intro/Knee Joint Overview LS1/15

Joints may be classified on the basis of structure or on the basis of the degree of allowable movement.

The structural differences are evident in the types of tissues holding the articulating bones together. Thus, joints may be:

A. Fibrous — held together by fibrous tissue

C. Synovial — characterized by the presence of a fibrous capsule lined by a synovial memebrane and a joint cavity filled with synovial fluid.

[Graphic: Explore the anatomy button]

In contrast, functional differences are revealed in the degree of movement permitted. A looser connection between articulating bones leads to a less encumbered movement. A joint may be classified as a(n):

A. Synarthrosis — immovable

B. Amphiarthrosis — slightly movable

C. Diarthrosis — freely movable

[Graphic: Explore the anatomy button]

Based on the characteristics of the three structural classes, which would you predict to be freely movable? (Hint: movement requires lubrication.)

A. Fibrous

C. Synovial

Which functional class must predominate in the appendicular skeleton?

A. Synarthrosis

B. Amphiarthrosis

C. Diarthrosis

[Graphic: Clear response.]

[Graphic: Submit response.]

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First IAA: Any suggestions about how to graphically illustrate the first concept (structural differences)?

Second IAA: Use existing IAA (which nicely illustrates functional diffs).

Notes: Same functionality as described in previous multiple choice activity.

Intro/Knee Joint Overview LS1/15

Functionally, the knee is considered a diarthrosis. Note the impressive range of motion allowed.

[Begin video button: Move video that currently opens unit to here.]

Of the three structural classes of joints (fibrous, cartilaginous, and synovial), synovial joints are always freely movable. The presence of a space between articulating bones (the joint cavity) permits movement of the bones at points of contact.

In contrast, fibrous and cartilaginous joints are held together by supportive connective tissue. The connective tissue prevents the bones from freely moving.

[Graphic: still graphic of synovial joint.]

The appendicular skeleton includes the appendages (the upper and lower limbs) and the girdles (pectoral and pelvic) to which they are attached. Our limbs are freely movable. Hence, these joints are considered diarthroses.

[Graphic: still graphic of appendicular skeleton.]

Move on to the next unit and investigate the unique characteristics of synovial joints.

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Notes: Video is played when students click on begin video button. Before that, it appears as still image.