Effectiveness of Manuel Therapy Methods in Pes Planus

1 Static Balance Measurement Static balance will be assessed using the Kinvent K-Plates (Kinvent, Montpellier, France), a reliable portable force plate with a 1000 Hz sampling rate. Participants will stand on one leg with hands on hips and the other leg flexed, focusing on a point 5 m away for 10 s. The test will be repeated with eyes closed. Postural oscillations (mm) and center of pressure (COP) (mm) data will be reported instantly via the mobile app. Each condition will be measured three times.

Dynamic Balance Measurement Dynamic balance will be assessed using the Y-Balance Test platform (Move2Perform, Evansville, USA). Participants will reach in anterior, posteromedial, and posterolateral directions while maintaining single-leg stance, hands on hips. The maximum reach distance(cm) in each direction will be recorded. After practice trials, three valid attempts per direction will be completed. Results will be expressed as normalized composite scores(%) relative to limb length.

Muscle tone (Hz), will be assessed using the Myoton-Pro myotonometer (Myoton SA, Tallinn, Estonia; ICC: 0.76-0.86). Measurements will be taken from the Tibialis Anterior, Medial and Lateral Gastrocnemius, Soleus, Achilles tendon, and Plantar Fascia. The 3 mm probe will be applied perpendicularly to the skin (<3% error). Each site will be tested in standardized positions (supine or prone) and measured three times to obtain mean values for each mechanical property.

Muscle stiffness (N/m) will be assessed using the Myoton-Pro myotonometer (Myoton SA, Tallinn, Estonia; ICC: 0.76-0.86). Measurements will be taken from the Tibialis Anterior, Medial and Lateral Gastrocnemius, Soleus, Achilles tendon, and Plantar Fascia. The 3 mm probe will be applied perpendicularly to the skin (<3% error). Each site will be tested in standardized positions (supine or prone) and measured three times to obtain mean values for each mechanical property.

Ankle dorsiflexion ROM will be assessed with the Weight-Bearing Lunge Test (WBLT), a reliable method (ICC > 0.90). Participants will lunge toward a wall, keeping the heel in contact with the floor. The maximum distance (cm) from the great toe to the wall at which the knee touches without heel lift will be recorded. At this final position, a digital inclinometer will be placed on the tibia's midline to determine the tibial inclination angle (°). Measurements will be taken on both limbs under identical conditions.

Skin surface temperature (°C) will be assessed using a FLIR E52 thermographic camera (240×180 px infrared resolution, 50 mK sensitivity). Images will be captured in a controlled environment (23 ± 1°C; 40-60% humidity) and analyzed offline with Flir ResearchIR Max 4. Participants will acclimate for 15 min before testing. The emissivity will be set at 0.98, rainbow palette (27-35°C scale) applied, and the camera placed 1 m away, perpendicular to the skin. In the prone position, plantar fascia and sole temperatures will be recorded; in standing, calf and Achilles tendon regions will be imaged, with the highest temperature (°C) documented for each area.