"Open your arms to change, but don't let go of your values" —Dalai Lama, His holiness the 14th the Dalai Lama Tenzin Gyatso, head of state and spiritual leader of Tibetan people. 1935-
This chapter investigates the elbow and forearm complex. By the end of this chapter, you should be able to:
Identify the bones, joints, soft tissue, and muscles of the elbow/forearm complex;
Discuss the relationship between the elbow and radioulnar joints and their contribution to functional movement;
List muscles that are prime movers in elbow flexion, elbow extension, forearm pronation and forearm supination;
Discuss the influence of gravity and body position in determining muscles acting on the elbow/forearm complex during functional motions;
Name muscle groups that function to position and move the elbow and forearm in specific functional activities;
Describe commonly encountered movement disorders of the elbow complex and their functional consequences.
Bethany has just met her new patient, Chris. Chris is a manager of a prosperous shoe store and presents with weakness in his grip and pain and swelling over the medial surface of his elbow, especially when he flexes his wrist. However, his chief complaint and concern is not the pain at the elbow but rather his weakened grasp, which is interfering with his ability to maintain the quickly changing stockroom. He complains of frequent incidences of what he calls "having the dropsies." Bethany knows that she must examine both his elbow and wrist area to identify the source of his pain and weakness. She needs to pinpoint the area of tenderness and make some recommendations to manage the pain and swelling. She must also test all of the muscles that are attached in the painful area and primarily involved in grasp. As Bethany begins her assessment and manual muscle tests on Chris, she is thinking of each of these muscles and their functions, and she is concerned about how she can convince this high-energy workaholic to limit his activity in order to rest the area.
The elbow region is a complex structure that includes three individual joints that are surrounded by only one capsule. The first two joints are the humeroulnar and humeroradial joints; these articulations are what we typically think of as the "elbow."Another joint, the proximal radioulnar articulation, is the third joint of the elbow complex. Even though this joint lies within the elbow capsule, it is technically not part of the elbow joint; it is where forearm rotation occurs and is not involved in movement at the elbow. Although motion occurs and an articulation exists between the humerus and radius, most of the contact and osteokinematic elbow motion comes from the humeroulnar rather than from the humeroradial articulation. These two articulations (humeroulnar and humeroradial) act as one joint, creating a modified uniaxial hinge joint with one degree of freedom. This ...