At the conclusion of this chapter, the reader will be able to:
Identify the key anatomical and biomechanical features of the elbow and forearm and their impact on orthopaedic manual physical therapy (OMPT) examination and intervention.
List and perform key procedures used in the OMPT examination of the elbow and forearm.
Demonstrate sound clinical decision-making in evaluating the results of the OMPT examination.
Use pertinent examination findings to reach a differential diagnosis and prognosis.
Discuss issues related to the safe performance of OMPT interventions for the elbow and forearm.
Demonstrate basic competence in the performance of a skill set of joint mobilization techniques for the elbow and forearm.
FUNCTIONAL ANATOMY AND KINEMATICS
The elbow joint complex is comprised of the humeroulnar, humeroradial, and the proximal and distal radioulnar joints, all of which serve the primary function of positioning the hand in space. The elbow joint proper (humeroulnar and humeroradial joints) functions as a loose hinge joint with one degree of freedom that permits movement in the sagittal plane about a frontal plane axis (Fig. 23–1). A small degree of frontal and transverse plane movement that serves to enhance function is also available. The proximal and distal radioulnar joints function collaboratively to provide transverse plane rotation about a longitudinal axis.
Anterior view of the elbow.
The Humeroulnar (HU) Joint
Positioned between the medial and lateral epicondyles of the distal humerus is the spherical capitulum, which comprises the lateral one-third of the humeral articulating surface. Occupying the middle two-thirds of the humeral articulating surface is the larger, spool-shaped trochlea, with its obliquely oriented central trochlear groove. Both the capitulum and the trochlea are covered by articular hyaline cartilage. Observation of bone density reveals that the distal humerus sustains its greatest loads anteriorly and distally.1 The trochlea protrudes anteriorly in relation to the humerus and the medial aspect of the trochlea extends more distally than its lateral counterpart. Orientation of the trochlea results in a valgus angulation of the forearm. The carrying angle is defined as the angle between the long axis of the humerus and the long axis of the ulna when the elbow is extended and fully supinated. The average carrying angle is considered to be 10 to 15 degrees in the frontal plane (Fig. 23–2).2 The coronoid fossa, which is just proximal to the trochlea, accommodates the coronoid process of the ulna when the elbow is fully flexed. The larger olecranon fossa receives the olecranon process of the ulna, thus producing the hard end-feel at terminal range of elbow extension.
The carrying angle of the elbow.