Medial forefoot extension
HeathyStep’s thermoplastic polyurethane (TPU) forefoot extension additions bring increased frontal plane stability to the acceleration phase og gait when most other orthotic features are no longer influencing foot motion. They require a full-length device to work and are suitable for use under any full-length orthosis, including a top-covered Vectorthotic and Alleviate Select.
These distally applied additions can be applied medially to resist acceleration eversion instability or they can be positioned laterally to resist inversion instability and low gear propulsion.
£4.20 – £8.40
Product Description
Suitable for all HealthyStep’s total surface-contact orthoses.
X-Line
Condition Specific
Alleviate
Arch Angel Fallen Arch, Active and Hiking Insole
Fitting the forefoot extension is simple. Just peel off the backing and apply as indicated below.
They can be fitted to Vectorthotic and Alleviate Selects as indicated below.
HealthyStep’s forefoot extensions appear to be the first standardised commercial additions for use under the distal top cover material. TPU makes them flexible enough not to irritate the forefoot and digits before or after heel lift. However, they are firm enough to direct acceleration power to make weight transfer easier when frontal plane stability is an issue at the end of the stance phase.
Additions placed on an orthosis beyond the metatarsal heads exert their primary effects during the acceleration phase of gait, just when the heel is lifted and the foot changes from being plantigrade to digitigrade (forefoot and toe ground contact only). This is the foot posture used throughout a whole step when forefoot running. This makes forefoot extension additions the primary foot orthosis mechanism to assist fast runners, like sprinters.
During human walking, digitigrade as opposed to plantigrade foot posture exists for a very short period. This occurs as a single-limb support event briefly after heel lift, just before the opposite foot’s heel contact, but it continues as part of double-limb stance after contralateral heel contact. After the opposite heel strike, digitigrade foot forces rapidly decrease as the weight swiftly transfers to the next step.
It is during the early digitigrade phase of gait around heel lift, that frontal plane instability can affect acceleration and cause the loss of momentum to the body weight driving it onto the next step.
Ideally, the foot should drive through the medial MTP joints, with the rearfoot sitting vertically to the ground. This is high gear propulsion or acceleration, which is mechanically the best foot action during the late stance phase.
If the ankle and rearfoot are seen to invert after heel lift, significantly causing a low gear acceleration, add the forefoot extension laterally.However, if the ankle-rearfoot is seen to evert after heel lift, add the forefoot extension medially.
