This article, the first in a two-part series, introduces and discusses the importance of movement and gait on the lower extremity in relation to chronic venous insufficiency (CVI) and chronic oedema (CO). It outlines and highlights the importance of the venous and lymphatic systems and their influence on how fluid is moved from the periphery into the trunk. The article introduces and explores the role of important anatomical systems like the veno-muscular pumps within the lower extremity, and how underlying  musculoskeletal (MSK) issues that affect movement and walking can influence
the onset, chronicity, and severity of CVI and CO. It also touches on how fluid is moved from the lower extremity into the trunk. Finally, the importance of compression and its benefits are explained through key scientific principles and the vital role that it plays in
fluid movement from the periphery into the trunk. The second part of the series will focus on how movement, orthotics and footwear can complement compression and their role in reducing peripheral oedema, improving gait and managing pain in the foot and ankle.