Most symptomatic pathologies of the ankle and hindfoot are determined by biomechanical alterations of this anatomical region. Surgical treatment of these pathologies is therefore aimed at improving the inferior biomechanical condition, and it can be expected that an improvement of the biomechanical parameters grossly parallels the targeted clinical improvement.

3D Multisegment Foot Models have been developed and validated to determine the clinical outcome. Such a validated 3D Multisegment Foot Model is now standard available in the gaitlab of UZ Leuven making it possible to study a huge amount of biomechanical parameters within the foot & ankle region itself.

Most symptomatic pathologies of the ankle and hindfoot are determined by biomechanical alterations of this anatomical region. Surgical treatment of these pathologies is therefore aimed at improving the inferior biomechanical condition, and it can be expected that an improvement of the biomechanical parameters grossly parallels the targeted clinical improvement.

Unfortunately, in the past, biomechanical examination of the lower limb and foot consisted of two distinct study protocols: gaitlab and plantar pressure measurements.

First, these two study protocols were acquired completely independently. Therefore, it proved to be very hard to compare the results and get insight in the way altered biomechanics caused or continued to cause abnormal plantar pressure distributions. However, recently it was possible to integrate these two modalities, especially concerning the timing of the events, what makes it possible to reliably link the observed findings.

Second, virtually all gaitlab models considered the foot & ankle region as one single segment, making it impossible to evaluate any biomechanical parameter within the targeted region. 3D Multisegment Foot Models have been developed and validated since the beginning of this century. Such a validated 3D Multisegment Foot Model is now standard available in the gaitlab of UZ Leuven making it possible to study a huge amount of biomechanical parameters within the foot & ankle region itself.

Furthermore, only a paucity of information is available if the observed clinical changes are indeed paralleled by an equally directed biomechanical change.

Historically, all patients at the Foot & Ankle unit of UZ Leuven performed a pre- and 1 year post-operative plantar pressure measurement to get better insight in their clinical condition. As stated before, the usefulness of this single testing method was limited. Recently the Advanced Clinical Examination Platform that integrates both plantar pressure measurement and full 3D MFM-gaitlab has been implemented in the Movement Analysis Laboratory of our institution. Currently a transition to routinely perform such an examination is finished. Therefore a completely new era of research concerning the biomechanical evaluation itself and clinical results of the reconstructive procedures of ankle and hindfoot has started.

Inclusion Criteria:

• Being routinely scheduled for a reconstructive surgical procedure for the following indications or involving the following type of procedure:

  1. Any reconstructive procedure for Pes Planus, Pes Plano-valgus, or Posterior Tibial Tendon Dysfunction

  2. Tibio-talar arthrodesis or prosthesis

  3. Sub-talar -and/or (partial) Chopart - and/or Triple arthrodesis

  4. Pantalar arthrodesis with or without inclusion of the Chopart joint

     Exclusion Criteria:

• Age under 18

• Need of tools (eg walker or crutches) to walk less than 100m

• Inability to walk less than 100 m anyway

• Differences in leg length exceeding 3 cm (measured clinically)

• Extreme in-or outtoeing

• Subjects with BMI > 27.5 require very careful further consideration whether or not the obesity prevents the accurate palpation of anatomical landmarks necessary prior to marker placement. This will be judged on an individual basis.