The Effect of Thyroid Dysfunction on Pain, Symptoms, Attitudes, Fatigue, Foot Parameters, Muscle Strength, and Lower Limb Performance in Women With a Menstrual Cycle: A Cross-Sectional Comparative Study

Sit-to-Stand Test

Time Frame: At baseline (Day 1)

This test evaluates individuals' lower extremity muscle strength and functional performance. In the starting position, the participant's arms are crossed in front of the torso and their feet are in full contact with the floor. Participants are asked to sit down and stand up as quickly as possible for 30 seconds from a standard chair with back support but no armrests. The total number of sit-to-stand cycles is recorded.

Trunk Flexor Endurance Test

Time Frame: At baseline (Day 1)

The participant lies down with the hips and knees flexed to 90°, arms crossed over the chest at shoulder level, and feet in a fixed position. The test begins when the participant's trunk is moved into a supported sitting position with 60° flexion while maintaining this initial position. The trunk support is removed, and the participant is asked to maintain this position for as long as possible. The test ends when the 60° angle between the floor and the upper trunk changes, and the elapsed time is recorded in seconds.

Trunk Lateral Flexor Endurance Test

Time Frame: At baseline (Day 1)

The participant lies on their non-dominant side on a treatment table with their legs extended. The upper foot is placed in front of the lower foot for support. The upper arm is placed across the chest toward the opposite shoulder. The elbow of the lower arm is positioned in flexion and placed so that support can be obtained from the elbow and forearm. The participant is instructed to lift their hips off the ground to form a straight line with their entire body, using support from their elbows and feet. The test ends when the participant loses the test position, and the duration for which the position was maintained is recorded in seconds. The test is performed bilaterally.

Longitudinal Arch Measurement

Time Frame: At baseline (Day 1)

This method, which describes the position of the navicular tubercle relative to the medial malleolus and the line of the first metatarsophalangeal joint, was first developed by McPoil and colleagues. The grading of pes planus is based on the degree to which the navicular tubercle deviates from the Feiss line and approaches the ground.

Foot Function Index

Time Frame: At baseline (Day 1)

This is a patient-reported outcome measure based on a patient-centered assessment approach that evaluates foot function from different perspectives. It consists of 23 items divided into three subscales: pain, disability, and activity limitation. For each item, patients are asked to rate their condition on a scale from 0 (no pain or difficulty) to 10 (the most severe pain imaginable or extreme difficulty making the activity impossible to perform). Scores for each subscale are calculated separately, and a total score is also recorded. The scores are transformed to a scale ranging from 0 to 100, where 0 represents the best possible outcome (no pain or difficulty) and 100 represents the worst possible outcome (the most severe pain imaginable or extreme difficulty making the activity impossible to perform).

Foot Posture Index-6

Time Frame: At baseline (Day 1)

The Foot Posture Index (FPI) is an assessment tool used to evaluate foot posture by observing the position of the rearfoot and forefoot across multiple planes. This assessment, which takes approximately 4-5 minutes, was performed bilaterally based on observation and palpation from the posterior, medial, lateral, and anterior aspects of the foot. A total of six parameters were evaluated, including three related to the rearfoot and three related to the forefoot. Each parameter was scored on a scale from -2 to +2, and both the total score and the subscores for the forefoot and rearfoot were recorded. The total score was used for interpretation, where 0 indicates a neutral foot posture, positive values indicate a pronated foot posture, and negative values indicate a supinated foot posture.