Final answer:
The HAMSTRINGS are most likely to cause genu recurvatum when weak because they are responsible for controlling knee flexion and counteracting excessive extension.
Step-by-step explanation:
The weakness of the HAMSTRINGS is most likely to result in genu recurvatum during stance. Genu recurvatum, also known as back knee or hyperextended knee, is a condition where the knee extends beyond the normal range of motion in the extended position. The hamstrings, which include the biceps femoris, semitendinosus, and semimembranosus, are responsible for knee flexion and act as a counterforce to prevent excessive knee extension.
When the hamstrings are weak, they are less effective at controlling the forward motion of the tibia, leading to hyperextension of the knee. In contrast, the other options, such as the tibialis anterior, quadriceps, and tibialis posterior, primarily function in different manners. The quadriceps extend the knee and the tibialis muscles are involved in ankle movements.