Relationship Between Pain, Anxiety and Fatigue and Knee Position Sense, Balance and Dual Task Performance During Menstrual Cycle in Females With Multiple Sclerosis

Lower abdominal and low back pain was questioned. Pain intensity was evaluated with a 0 to 10 cm visual analog scale (VAS): "0" indicated "no pain" and "10" indicated "the worst imaginable pain \[18\]. Pain that developed during the activity was also questioned and stated as pain+ activity. A higher score indicates a more severe pain.

Fatigue was assessed by the Fatigue Severity Scale (FSS). This is a 9-item questionnaire that assesses the effect of fatigue on daily living. Each item is a statement on fatigue that the subject rates from 1 "completely disagree" to 7 "completely agree". A score of 4 or higher generally indicates severe fatigue.

The Spielberger State Trait Anxiety Inventory (STAI) was used to evaluate levels of anxiety. The state part of the STAI is a 20-item self-report inventory designed to measure state anxiety (current feelings of apprehension, worry, etc.). The STAI state scale is scored on four levels of anxiety intensity from 1 "not at all" to 4 "very much" and with a total score between 20 and 80. A higher total score indicates a more severe anxiety level.

Knee position sense was evaluated with a Acumar dual digital inclinometer. Each participant was asked to wear shorts and to lie down in supine position treatment table. The lower extremity of the participant was positioned in neutral for the knee flexion movement. The placement of the digital inclinometer's attachment was the lateral ridge of the femur and tibia. We actively assisted the participant's knee to the target angle and asked the participant to hold it there for 5 seconds before returning the knee to the starting position. After returning to the starting position, participants attempted to repeat the previously attained angle. Participants indicated verbally when they felt they had reached the angle and held their position. This procedure was repeated 3 times for each limb (non-dominant and dominant). We measured the absolute difference between the target angle and the observed angle and calculated the absolute error score by averaging the 3 trials.

The Biodex Balance System (Biodex Medical Systems, Shirley, NY, USA) was used to measure limits of stability. The participants were asked to position themselves in a comfortable position on the platform and their foot position coordinate was recorded. The participants were asked to complete as quickly as possible the directional tasks displayed on a screen, with the directions displayed at random. A total of 3 tests were performed, at intervals of 10 s. A total score was recorded. The higher the total score, the better the ability of the subjects to transfer the center of gravity.

The timed up and go test (TUG) was used in the evaluation of dual task performance. For this test, participants were seated on a standard armless chair and a cone was placed 3 meters away from the chair. Participants were instructed to stand up and (1) walk towards the cone, (2) turn around the cone, (3) walk back to the chair, and (4) sit back on the chair. It was stated that patients should walk without running but as fast as possible. TUG test was performed initially without task, and then with cognitive and motor tasks, respectively. Cognitive task given during the test is counting three backwards from 100 or counting the names starting with the letter "A", and motor task given is to carry three glasses of water on a tray. The time elapses between standing up from the chair and sitting back to chair was recorded as the test result. As time increases, dual task performance decreases.