Which technique is critical for safe ascending of a fixed line?

Proper foot placement and movement are crucial for safely ascending a fixed line because they provide the necessary stability and balance during the climb. Utilizing the feet effectively allows the climber to distribute their weight evenly, reducing strain on the arms and minimizing fatigue. Good footwork enhances traction and control, enabling the climber to navigate obstacles and maintain a steady ascent.

In contrast, relying solely on hands can lead to exhaustion and diminish the climber's overall stability. A belay device is important for safety but doesn't directly contribute to the technique of ascending the line itself. Leaning backward, although it may offer balance when needed, does not provide support in the same way that proper foot placement does during the ascent. Thus, focusing on foot placement and movement is key to ensuring a safer and more efficient climb.