15 Introductions to Joints and Bones of the Upper Extremity
Learning Objectives:
- Name the bones of the upper extremity and describe their functions.
- Identify key landmarks on the bones of the upper extremity and explain their function or purpose.
- Identify and describe the joints of the upper extremity, the bones that make up those joints, the movements possible at those joints, and any key accessory structures that are part of the joint (e.g., bursae or ligaments).
- Explain structure governs function examples from the bones and articulations of the upper extremity (i.e., how is the degree of joint movement determined by the structure of the joint).
Terms to Know
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Introduction
In this lab, you will learn about the bones of the upper extremity. We will discuss the bones, joints, muscles, nerves, and vasculature that make up our shoulder region, arm, forearm, and hand during this unit. Be sure to check the course Canvas page, as we will be providing you with a bony landmark chart and muscle charts (muscle chart 1 & muscle chart 2) to help clarify what material you will be responsible for and help you learn the material.
This lab focuses on the bones of the upper extremities, including the scapula, humerus, clavicle, ulna, radius, carpals, metacarpals, and phalanges. You will be asked to identify specific landmarks on these bones. You are encouraged to look at several different bones of the same type (i.e., several different humeri), as sometimes these features are more or less prominent due to anatomical variation. Finally, based on the landmarks, you should identify if individual bones come from the right or left upper extremity. Students are encouraged to reference the muscle and bone landmark charts to better understand origin and insertion landmarks on the bones. You are responsible for knowing the bony landmark origins and insertions for many of the muscles of the upper extremity, as indicated on the muscle charts linked above.
Lab Activities
Activity 1: Bony landmarks of the upper extremity
Using the bony markings table, the bone walk-through videos, and videos of the digital atlas in Canvas identify the bones, bony landmarks, and bony markings of the lower extremities. You can also view these structures in drawing form through the Netter’s atlas and in bone images in the Abrahams’ atlas. In both of these sources, you can also find images with overlays of attachment sites, so you can begin to make connections between the bones and the muscles.
- Observe the scapula, clavicle, and humerus. You should be able to identify the landmarks listed in the bony markings chart. You will be responsible for the information in that chart, and these markings will be reviewed again as we discuss the rest of the upper extremity.
- You should also be able to identify if these three bones come from the right or left side of the body. By knowing if a certain landmark is medial or lateral, anterior or posterior, you should easily determine the side of the body the bone came from. For example, the medial epicondyle is larger than the lateral epicondyle of the humerus, and the large olecranon fossa is posterior. By knowing this, you should determine if you are looking at a right or left humerus.
Activity 2: Radiology-Bones of the Upper Extremity
The most common way that you will see bones in the clinical setting is through radiology. Therefore, you need to understand what normal bony anatomy looks like in radiological images. In this activity, you will use radiology in Canvas to identify landmarks on the bones of the upper extremity. You will primarily examine x-ray images, but there will be a few MR images as well.
Compare the landmarks on the skeleton to the radiological images along the way. This will help you to make sense of what you see in the images. You can also use an atlas to compare the bones with the radiology.
Wrap up and Clinical Connection
For today’s clinical connection, we will look at common bony injuries to the upper extremity. There are radiographs of fractures to the humerus, radius, and scaphoid. The radiographs are excellent ways to review anatomy. Note the radiographs of the glenohumeral dislocation and associated fracture. When you understand your bony anatomy, it is easy to see when the anatomy does not look normal. There is also a unique case of a growth plate injury to a skeletally immature patient. The MRI, in this case, reviews some of the bony anatomy of the shoulder. Remember to look at bony anatomy with multiple modalities. Work on understanding what the normal anatomy should look like, orient yourself to images, and find bony landmarks.