The constant flexion and extension of your ankles during the pedal stroke was long considered desirable for a fluid and efficient pedalling technique.
However, comprehensive analysis of pro cyclists’ video footage has shown no evidence that they consistently display significant ankling action. Some cycle with their toes more pointed, some with almost flat feet, while some exhibit a degree of flexion, but there’s no pedalling technique consensus.
Rather than focussing on what your ankles are doing, if you’re concerned about your pedalling technique and efficiency, your priority should be getting a physio-led 3D motion-capture bike fit. There’s little point trying to improve your pedalling style if your position on the bike isn’t right. In fact, excessive ankling can be a sign of incorrect saddle height.
Once you’re happy with your position, training tools such as Wattbike’s Polar view are great for dialling in your technique. A more traditional way to develop perfect pedalling are rollers. If the whir of the rollers is constant, it means your pedal stroke is smooth and even.