Investigation of the Relationship Between Core Muscles Functions and Symptoms of Patients with Abdominal Bloating/Distension

Primary outcomes

1. Superficial Electromyography (EMG)

   Time frame: At the time of the initial physiotherapist examination

   A NeuroTrac MyoPlus 4 PRO (Verity Medical LTD., UK) type EMG device will be used in the study. Bioelectrical activities of the muscles (pelvic floor muscles, abdominal muscles, diaphragm, multifidus, erector spina) will be recorded with disposable 3.2 x 3.2 cm superficial electrodes. To reduce skin impedance, the skin area will be cleaned with an alcohol swab. Active electrodes will be placed on the right side of the body, parallel to the muscle fibers, according to the reference points. The reference electrode will be placed on the anterior superior iliac spine. Measurements will be performed during six seconds of maximal voluntary contraction ('work' phase EMG activity) and sixseconds of relaxation ('rest' phase EMG activity) of the pelvic floor muscles. Measurements will be repeated for three times. The graphic and numerical data provided by the device will be recorded in the evaluation form.

2. Ultrasonography (USG)

   Time frame: At the time of the initial physiotherapist examination

   Pelvic floor displacement, bladder wall thickness and, abdominal muscles, multifidus, erector spina, diaphragma, intercostal muscle thicknesses, anorectal angle, anopubıc angle will be measured. A transabdominal diagnostic USG device (Sonospace SSI-600) with a low frequency (2-5 MHz) curvilinear transducer will be used. Muscle thickness and distance measurements will be made during frozen imaging. Muscle thickness will be measured between the upper border of the muscle fascia, which appears as a white line, and the end point of the lower border. Measurements will be taken at the expiration and during a five-second pelvic floor muscle contraction. Both measurement results will be recorded in millimeters. All measurements will be repeated three times and the average values will be noted on the evaluation form

3. MIP-MEP Measurement

   Time frame: At the time of the initial physiotherapist examination

   One of the most commonly used non-invasive methods for evaluating respiratory muscles is the measurement of Maximum Inspiratory Pressure (MIP) and Maximum Expiratory Pressure (MEP). These are pressures measured within the oral cavity during maximal respiration against a closed airway. MIP (Maximum Inspiratory Pressure) is the highest pressure generated to open closed alveoli at the level of residual volume (actually negative pressure). For the test, the subject is asked to perform maximum expiration, and at the end of this, the airway is occluded with a valve, prompting the individual to perform maximum inspiration and sustain it for 1-3 seconds. MEP (Maximum Expiratory Pressure), on the other hand, is the highest pressure required to deflate over-distended alveoli at the level of total lung capacity. After instructing the individual to perform maximum inspiration for MEP measurement, they are asked to perform maximum expiration against a closed airway for 1-3 seconds.

4. Gastrointestinal Symptom Rating Scale

   Time frame: At the time of the initial physiotherapist examination

   The scale evaluates how individuals have felt regarding gastrointestinal issues in the past week. The scale consists of 15 questions with 5 subscales: reflux, indigestion, diarrhea, constipation, and abdominal pain. Higher scores obtained from the scale indicate more severe symptoms.