Longitudinal foot position with the ball of the foot above the
pedal axle.

Ankling is in fact rolling off the foot during the pedal stroke.

FOOT POSITION
The last variable, according to Gonzales and Hull (1989), is
the longitudinal position of the foot. This position is mainly
determined by the adjustment of the shoe cleats. For this variable
there is one rule, which stipulates that the shoe cleat should
be adjusted in the longitudinal direction of the foot in such
a manner that the ball of the foot (the metatarsal head) is
exactly above the middle of the pedal axle (Mandroukas, 1990).
This adjustment of the foot stimulates the process of "ankling",
which results in a regular cycling pace and an effective position
of the pedal in relation to the position of the crank (Haushalter
1994).
When the ball of the foot is placed in front of the pedal axle,
the effective leverage from the ankle to the pedal axle is reduced.
This way it is easier to stabilize the foot on the pedal, and
it leads to a decreased tension on the Achilles tendon and the
calf muscles. Some triathletes and time trial cyclists choose
this option because the increased stability of the foot enables
them to shift into a higher gear. The possibility of achieving
higher pedaling frequencies is limited by this adjustment and
the ankle pattern is a lot less regular, especially in the upper
and lower positions, because the possibility of deviation in
the ankle joint is limited.
When the ball of the foot is placed behind the pedal axle, the
effective leverage is enhanced, making it more difficult to
stabilize the foot on the pedal. The consequence of this position
is that the Achilles tendon and the calf muscles are under increased
strain in order to maintain sufficient rigidity of the foot.
This method is sometimes adopted by track cyclists because it
enables them to achieve a higher pedaling frequency.
The position of the foot (shoe) on the pedal not only has consequences
for the possible occurrence of injuries, particularly of the
knee, but it also affects the efficiency of the pedaling movement.
adjusting shoe cleats, one
often tries to realize the most natural position of the feet
on the pedals; however, when doing so, one should bear in mind
that cycling with feet in a fixed position is an imposed movement.
This means that the circular movement of the pedals is imposed
on the cyclist, and the cyclist has no choice but to adapt to
the drive mechanism of the bicycle.
When shoe cleats are adjusted correctly, the knee remains in
the axle that runs from the hip joint to the ball of the foot
during the cycling process. Every deviation, both inward as
well as outward, results in loss of effectiveness.