Final answer:
For a massage of the anterior leg, the knee should be supported and slightly flexed to relax the muscles and protect the knee's supporting ligaments, including the cruciate and collateral ligaments.
Step-by-step explanation:
When massaging the anterior leg, it is generally best if the knee is supported and slightly flexed. This position allows for relaxation of the muscles and accessibility for the therapist. It is also helpful as it avoids stress on the knee joint. Supporting the knee can help prevent hyperextension and protect the ligaments that support the knee joint, such as the anterior and posterior cruciate ligaments and the tibial and fibular collateral ligaments. If the knee is extended, the collateral ligaments on the sides of the knee become tight, which helps stabilize it, but may not be desirable during massage intended for relaxation of the muscles. Flexion of the knee, by contrast, involves a decreased angle between the bones and is facilitated by muscle groups such as the hamstrings, making it a more suitable position for massage. When considering knee flexion and extension, key muscles in the process include the quadriceps femoris as agonists of knee extension and hamstrings as antagonists for knee flexion.