Impairments of the lymphatic system can lead to lymphatic insufficiencies that can result in significant physical impairments and subsequent loss of function of either the upper or lower extremities. Disturbances in structure or function can lead to accumulation of lymphatic fluids in the tissue of the body that affect the physiological health of the tissue, impair joint mobility, and impact daily functioning. Lymphatic dysfunction can be a result of a congenital or hereditary abnormality or can be caused by trauma, infection, or treatment for a cancer.
To contribute to the effective management of patients with lymphatic disorders, a therapist must possess a sound understanding of the underlying pathologies and the clinical manifestations of many types of lymphatic disorders, as well as the interplay between the lymphatic and venous systems. A therapist must also be aware of the use, effectiveness, and limitations of therapeutic exercise in the comprehensive management and rehabilitation of patients with lymphatic insufficiencies.
Disorders of the Lymphatic System
Structure and Function of the Lymphatic System
The primary function of the lymphatic system is to collect and transport fluid from the interstitial spaces back to the venous circulation (Fig. 25.1).30,35,47,52,105,107 This is accomplished with a series of lymph vessels and lymph nodes.30,35,107 The lymphatic system also has a role in the body's immune function.30,105,107 When the lymphatic system is compromised either by impairment of lymphatic structures or by an overload of lymphatic fluid, the result is swelling in the tissue spaces. Edema is a natural consequence of trauma to and subsequent healing of soft tissues. If the lymphatic system is compromised and does not function efficiently, lymphedema develops and impedes wound healing.
Major vessels of the lymphatic system.
Lymphedema is an excessive and persistent accumulation of extravascular and extracellular fluid and proteins in tissue spaces.11,18,26,47,61,107 It occurs when lymph volume exceeds the capacity of the lymph transport system, and it is associated with a disturbance of the water and protein balance across the capillary membrane. An increased concentration of proteins draws larger amounts of water into interstitial spaces, leading to lymphedema.26,41,107 Furthermore, many disorders of the cardiopulmonary system can cause the load on lymphatic vessels to exceed their transport capacity and subsequently cause lymphedema.41,61
Anatomy of the Lymphatic System
The lymphatic system is an open system.30,57,107 The lymphatic capillaries are situated close to the blood capillaries and are responsible for pulling the fluid into the lymphatic circulation (Fig. 25.2).30,...