Every cyclist or triathlete have cycling technique faults and one of the most common problems is the range of motion at the ankle.
There are two main common problems at the ankle which have different consequences:
Plantarflexed foot:
This is when the foot points down too far at the bottom of the pedal stroke. To achieve this the calf muscles must contract which fatigues them unnecessarily: cyclists often complain of tired calves or cramping, especially later in a ride or when running off the bike. The plantarflexion is often accompanied by clawing of the toes which can lead to cramping in the arch of the foot.
For cyclists this is inefficient but for triathletes the problem continues into the run. The muscles at the back of the lower leg and under the foot are essential during gait and if fatigued won’t be able to maintain an efficient gait during the run. The muscles are less effective at supinating the foot so propulsion is reduced and combined with more pronation (and internal leg rotation) efficiency is further compromised and the run split will be affected. The longer the run the more destructive this inefficiency will be.
Dorsiflexed foot:
This is when the heel drops too far at the bottom of the pedal stroke. The lower the heel the greater the tension there is on the Achilles tendon: as well as being inefficient this often leads to Achilles pain which can affect training, especially when running.
There are three main reasons why these two problems occur:
The person has no idea they’re making the mistake and corrects the fault once it has been highlighted.
There is a mistaken belief that more leverage is achieved by actively trying to plantarflex or dorsiflex the foot
The fault is a compensation for an incorrect saddle height
Plantarflexion is usually associated with a saddle which is set too high. By pointing the foot down the rider is basically trying to reach the pedals which are too far away. The alternative compensations are to over-extend the knee and/or drop the hip to ‘extend’ the leg.
A dropped heel is usually because the saddle is too low and the rider is subconsciously trying to achieve more leverage by achieving more extension at the knee.
Trying to achieve more power through the ankles is a mistake: the work is achieved through the quadriceps, hamstrings and glutes as the hip and knees extend towards the bottom of the pedal stroke.
Conclusion:
To achieve efficient ankling the muscles around the lower leg, ankle and foot should be relaxed. There should be enough passive tension for the muscles to help transfer the power generated by hip and knee extension.
By relaxing these muscles and scraping the foot through the bottom of the pedal stroke efficiency is increased without any unnecessary fatigue in the lower leg or foot.