In a conventional AFO with double action ankle joints, what setup is most appropriate for a patient who buckles at the knee during loading response?

In a conventional ankle-foot orthosis (AFO) with double action ankle joints, the goal is to provide optimal support and stability to the knee during the loading response phase of gait, particularly for patients who experience knee buckling.

The setup that includes springs in the posterior channel along with pins in the anterior channel is designed specifically to allow for controlled flexion and extension of the ankle while limiting excessive dorsiflexion, which can contribute to knee instability. The springs in the posterior channel provide some resistance against ankle dorsiflexion, which helps to maintain a more stable knee position during weight-bearing. This resistance indirectly contributes to the stability of the knee by maintaining alignment during the loading response.

The addition of pins in the anterior channel serves to lock the joint in a more stable position during the early phases of stance, preventing undesired movement that can lead to further knee flexion and potential buckling. This combination creates a synergistic effect where the posterior springs provide some dynamic support in allowing controlled movement while the anterior pins ensure that the ankle doesn't collapse forward, reinforcing the stability necessary to prevent the knee from buckling under load.

In summary, this setup effectively balances mobility and stability, crucial for a patient struggling with knee control during the loading response,