Trial Outcomes & Findings for Effectiveness of Core Stability Exercises on Foot Posture, Function and Limb Alignment in Flexible Flat Feet Patients (NCT NCT06567509)

Participants were enrolled into two main trial arms: core stability and control. Initial pilot work was conducted to finalize study procedures and sample size calculations. All participants included in the analyses correspond to the main trial.

This study included both pilot and main trial phases conducted under the same protocol and registration. Participants enrolled during the pilot phase were assigned to pilot control and pilot experimental arms and are reported separately from the main trial arms. All participants from both phases are included in the overall enrollment and results reporting to ensure consistency with the registered study design.

Effectiveness of Core Stability Exercises on Foot Posture, Function and Limb Alignment in Flexible Flat Feet Patients

A 5 mm rubber pad was inked and used to ink the participant's foot. Participants sat first, then placed the testing foot on the inked pad and stood in tandem stance with the non-testing foot outside. A half-squat with slight hip and knee flexion ensured full foot contact. The inked foot was then placed on A4 paper while repeating the half-squat to transfer a clear footprint. A line of tangency from most medial foot edge and the heel was drawn using a ruler. Perpendicular line was drawn from midpoint of this line, crossing foot. Same procedure was repeated for heel tangency point. This process provided the measurements of the support width of the midfoot region (A) and the heel region (B) in millimeters. The Plantar Arch Index (PI) was then calculated using the formula (Plantar Arch Index (PI)=A/B) in millimeters. 0.8 mm = flexible flatfoot ↓ Arch Index = improvement (Putu Janiartha et al., 2023) Values represent mean change scores (post-pre), comparisons performed using MANCOVA

The rear foot angle (RFA) will be used to assess the calcaneal valgus. Four points will be marker in the lower limb with the subject is in standing position with talus in neutral position: Base of calcaneus as mark 1, Subtalar joint (Centre of Achillies tendon attachment) as mark 2 and centre of posterior aspect of calf 15 cm above the 2nd mark as mark 3. A straight line will be drawn using a marker from point 2 to point 1. Then a line will be drawn from point 3 to point 2. The angle formed between the two lines with point 2 as fulcrum is the rare foot angle and will be measure using a universal goniometer. The values represent mean change scores (post-pre). Group comparisons were performed using MANCOVA.

The 'Q angle' will be measured by extending a line from anterior superior iliac spine of the pelvic bone to the center point of patella and extending another line from tibial tubercle of tibia to the center point of patella. The junction between these two lines is the 'Q angle' and will be measured using a universal goniometer. Values represent mean change scores (post-pre).

The Foot Function Index (FFI) was initially included as an outcome measure in the study protocol. However, during the implementation phase, it was found to have feasibility limitations and reduced sensitivity in detecting changes within the study population. Therefore, the FFI was not collected for the main trial, and no data are reported for this outcome.

Isometric extensor test: The subject will lay down prone on the bed with his or her lower body from ankles to hips fixed to the testing bed. A chair of the height of the testing bed will be placed in front of the bed so that patient's upper body can be rested on. Then slowly the chair will be removed, and the patient will be asked to maintain the extension of trunk with two hands crossed over on the opposite shoulders. Time in seconds will be recorder using a stopwatch from the time the subject assumed the horizontal position till the patient deviates from the horizontal position or patient verbally quits the test. This outcome was collected as exploratory measure but was not included in the final analysis.

Isometric flexor test: The flexor endurance will be tested by asking the subject to lay in a sit-up posture with hips and knees flexed 90 degrees and the back resting against a wedge inclined at 60 degrees and hands of subject are on the opposite shoulders with toes strapped. The posterior wedge is pulled backwards 10 cm and the subject is allowed to maintain the flexed posture as long as possible and the time from the removal of wedge till any postural deviation is noted using a stop watch. Deviation is noted if the back touches the wedge. This outcome was collected as an exploratory measure but was not included in the final predefined outcome analysis.

Side bridges test (Left and right): The subject is instructed to lie inside bridge position and place one elbow 90 degrees flexed below the shoulder, and the legs are extended in line with the trunk with one foot positioned in front of the another. the second hand is crossed and kept on the opposite shoulder. The test will then be started with the patient lifting his or her pelvis from the ground and maintaining this position and the failure will be if the back no longer remains straight or if the pelvis drops to the floor. The time will be noted using a stopwatch. The test is performed for both right side and left side. This outcome was collected as an exploratory measure but was not included in the final predefined outcome analysis.