An observational study in Hemophilia, sponsored by Yuzuncu Yil University. Recruiting at 1 site in Turkey (Türkiye). Open to male participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-10-01.
Sponsored by Yuzuncu Yil University · Observational
Recurrent joint bleeding (hemarthrosis) occurs in 70-80% of cases of hemophilia. The three most frequently affected joints are the synovial joints of the ankle, knee, and elbow. Among these, the ankle and knee are the most common sites of bleeding, accounting for 80% of cases (Stephensen et al., 2009). This susceptibility stems from factors such as the fact that the knee and ankle are weight-bearing joints and are highly exposed to trauma.
Hemophilia treatment aims to reduce the frequency of bleeding episodes through prophylactic factor replacement; however, joint bleeding can recur despite treatment, potentially leading to permanent joint damage. This joint disease causes pain, reduced range of motion, and potential impairment of postural balance, while also increasing the risk of falls.
Due to its complexity and significance for the individual, gait assessment is a crucial component in evaluating mobility, functional capacity, and rehabilitation progress across various populations, including the elderly, individuals with neurological disorders, and those recovering from injuries. Various clinical tests and technological tools are available to measure different aspects of gait, such as walking ability, endurance, adaptability, and fatigue. Timed walking tests-such as the Timed Up and Go (TUG) test, the 2-Minute Walk Test (2MWT), the 6-Minute Walk Test (6MWT), the 10-Meter Walk Test (10MWT), and the Timed 25-Foot Walk Test (T25FW)-measure gait speed, endurance, and overall walking ability. A common feature of these tests is that they involve walking along a straight path with little to no change in direction; while this makes them effective in standardized clinical settings, they are relatively less suitable for assessing the complex mobility demands of daily life. In contrast, the Figure-8 Walk Test (F8WT) requires continuous changes in direction and turning, thereby challenging anticipatory postural adjustments, spatial navigation, and motor planning. Literature has demonstrated that walking along a curved path challenges dynamic balance and increases gait variability, revealing deficits-particularly in the elderly and in individuals with neurological or cognitive impairments-that are not apparent during straight-line walking.
In their daily lives, people frequently encounter curved paths and changes in walking direction-such as walking around a table, turning a corner, or avoiding an obstacle. The ability to successfully adapt one's gait and safely execute turns or changes in direction is fundamental to an individual's mobility and independence.
The Timed Up and Go (TUG) test is a widely used, performance-based clinical assessment tool for measuring lower-extremity function, mobility, and fall risk in individuals; its reliability and validity are well-established. The ABC scale is a 16-item measure used to assess balance confidence while performing specific activities both indoors and outdoors; it has also been proven reliable and valid. Among older adults, a score of 76% or lower indicates a risk of falling. The Weight-Bearing Lunge Test (WBLT), which assesses ankle dorsiflexion mobility, has demonstrated excellent test-retest reliability in patients with hemophilia, even in those with limited joint damage. Another test that is reliable and shows strong correlation with other functional measures in individuals with hemophilia is the Four Square Step Test (FSST). The FSST is associated with age rather than the severity of hemophilia and provides clinicians with information regarding the speed and ability to change direction and step over obstacles. The Y Balance Test (YBT) is a dynamic balance and postural control assessment that is increasingly preferred for use with patients with hemophilia in recent years.
Since the F8WT requires continuous changes of direction, it demands greater dynamic balance, spatial planning, and gait adaptation. It is important to examine the validity and reliability of the F8WT-which assesses change of direction, dynamic balance, agility, and functional mobility-in patients with hemophilia. The fact that the F8WT is easy to administer, quick to complete, and requires minimal equipment offers significant advantages for clinical use. However, no study evaluating the psychometric properties of this test in patients with hemophilia has been found in the literature. The aim of this study is to investigate the test-retest reliability and construct validity of the F8WT and WBLT in adult patients with hemophilia.
866 studies on the registry are indexed under Hemophilia A; 137 are open to participants now.
This study's planned enrollment of 36 is below the median of 80 across 314 observational studies indexed under Hemophilia A.
Browse Hemophilia A studies →Yuzuncu Yil University is the lead sponsor of 66 studies on the registry; 18 are open to participants now.
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Hemophilia patients aged with 18-65 years
Exclusion Criteria:
Figure-of-eight walk
The Figure-of-Eight Walk Test (F8WT) involves sitting on and rising from a chair. First, a rectangle measuring 3.6 meters in length and 2.4 meters in width is marked on the floor, and cones are placed at the two rear corners (along the length). A chair is positioned 2.4 meters away from the cones on either side, and the participant sits facing forward. Upon the start signal, the participant rises from the chair, walks clockwise around the rear-right cone as quickly as possible, returns to the chair, and sits down. Immediately afterward, they stand up, walk counter-clockwise around the rear-left cone, return to the chair, and sit down; this procedure is repeated twice, with an interval of 3-4 days between sessions.
Time frame: Two measurements: Baseline and another 3-4 days after baseline
Weight-Bearing Lunge
In this test, participants stand barefoot facing a wall; the test foot is positioned parallel to a measuring tape fixed to the floor, while the opposite foot is placed one foot-length behind. Participants perform a forward lunge, lightly touching their kneecap against the wall while maintaining heel contact. The test foot is moved backward in increments of approximately 1 cm until heel contact can no longer be maintained, and the distance between the toes and the wall is recorded in centimeters. The lunge position will be used to measure ankle dorsiflexion.
Time frame: Two measurements: Baseline and another 3-4 days after baseline
Timed Up and Go
Participants are instructed to rise from a chair with armrests (seat height: 42-46 cm), walk a distance of 3 meters (m) to a cone in a comfortable and safe manner, and then return to the chair and sit down again. The time taken to complete the task is measured using a stopwatch with a precision of 1/100th of a second. Timing begins with the word "start" following a 3-second countdown, and the timer is stopped when the participant is fully seated. TUG tests are administered by the same evaluator on two separate occasions, and the average time is recorded.
Time frame: Two measurements: Baseline and another 3-4 days after baseline
Five Times Sit to Stand
It measures the time it takes for a person to stand up from a seated position and sit back down five times. To perform the test, the person must sit on a chair with their arms crossed over their chest and their back resting against the backrest. Therefore, the chair should have a straight backrest, and a seat height of 42-46 cm is recommended. Upon instruction, the person must stand up fully and then return to the seated position; this action is to be repeated five times, and the activity should be performed as quickly as possible.
Time frame: Two measurements: Baseline and another 3-4 days after baseline
Four Square Step Test
It is a widely used dynamic balance test that clinically assesses an individual's ability to step forward, sideways, and backward over objects. The test consists of four wands of equal width arranged in a cross pattern. Participants are instructed to step sequentially in a clockwise direction into the squares numbered 1 through 4-specifically in the order 2, 3, 4, 1, 4, 3, 2, and 1-as quickly as possible without striking the wands (Figure 2). A shorter completion time indicates better performance. This measure demonstrates high validity and reliability. Completion times of 15 seconds or longer indicate a risk of falling.
Time frame: Two measurements: Baseline and another 3-4 days after baseline
Activities-specific Balance Confidence Scale
It is a 16-item questionnaire used to assess an individual's self-perceived level of balance confidence while performing activities of daily living. The total ABC score ranges from 0 to 100, with higher scores indicating greater balance confidence.
Time frame: Two measurements: Baseline and another 3-4 days after baseline
Y-Balance Test
Participants will perform the test barefoot while standing on one leg. While maintaining balance on one leg, they are required to extend the opposite leg as far as possible in the anterior, posterior, medial, and lateral directions. Prior to the test, leg length is measured from the anterior superior iliac spine to the distal end of the medial malleolus. Participants complete six practice trials in each direction to familiarize themselves with the procedure, followed by three recorded test trials. The maximum reach distance in each direction is recorded and normalized to leg length.
Time frame: Two measurements: Baseline and another 3-4 days after baseline
HJHS
Joint health will be assessed using the Hemophilia Joint Health Score (HJHS). The HJHS bilaterally evaluates the knee, elbow, and ankle joints-the sites where bleeding most frequently occurs in hemophilia. The total score is calculated by adding the gait score to the scores of the six index joints. It is a valid and reliable scoring system frequently used in the literature to evaluate joint health in hemophilia. In our study, in addition to the index score for each joint, the total lower-extremity index joint score will also be calculated.
Time frame: Two measurements: Baseline and another 3-4 days after baseline
Ankle Dorsifleksiyon Angle
With the patient lying in the supine position, a roll is placed under the knee. The axis of the goniometer is aligned with the lateral malleolus. The stationary arm is held parallel to the long axis of the fibula. The movable arm follows the lateral border of the fifth metatarsal. The ankle is moved into dorsiflexion. The final dorsiflexion angle is recorded in degrees. A high degree indicates good ankle mobility.
Time frame: Two measurements: Baseline and another 3-4 days after baseline
Plan to share: Undecided
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Yuzuncu Yil University