Inspiratory Muscle Training on Diaphragm Thickness, Inspiratory Muscle Strength and Shoulder Pain in Tennis Player

The thickness of the diaphragm will be measured using ultrasound, with a Toshiba Xario 100 ultrasound machine. Image acquisition will be performed by a physiotherapist experienced in musculoskeletal ultrasound. A linear probe (Toshiba PLT-805AT) with a frequency range of 8 to 12 MHz and a 54 mm probe footprint will be used to perform transcostal measurements at rest and in the supine position, using the B-Mode of ultrasound imaging (preset at 3 cm depth, 12MHz frequency, 64 gain points, 64 dynamic range points, and a single focus point located at 2 cm depth). Bilateral transcostal images will be obtained with the linear probe placed perpendicular to the last intercostal space, allowing for adequate visualization of the diaphragm without invasion of lung tissue during normal breathing

Inspiratory muscle strength will be measured using a portable device, POWERbreathe KH1. It is a simple test in which the subject performs a maximal forced inspiration against an airway occlusion mechanism in the mouth after a slow and prolonged near-residual volume expiration, yielding the maximum inspiratory pressure (MIP) value. The evaluation will be conducted with the subject seated in a chair (knees and hips at 90º), and their nose will be occluded with a clip. The advantage of this test is that it provides a quick and non-invasive way to assess inspiratory muscle strength through maximum inspiratory pressure. Three measurements will be taken, with 1 minute of rest between each measurement, and the best of the three will be selected, provided that there is no more than a 10% difference between them

Shoulder pain will be measured using the Visual Analog Scale for Pain (VAS), which is a valid and reliable measure for assessing pain. Its validity has been demonstrated with high correlations to other pain measures (r=0.62 to 0.91), and it has good test-retest reliability (r=0.94 to 0.71)(31). Participants will indicate their maximum pain sensation during the past week using a 100-mm VAS, where 0 represents 'no pain' and 100 represents 'extreme and unbearable pain

the measurement of pressure pain using an algometer will be performed at the upper trapezius, the levator scapulae, the middle deltoid, and the infraspinatus muscle as shown by studies at the shoulder level. The contact area will be 10mm, and it will be applied at a rate of 30 kPa/s. Patients will be instructed to signal the moment they feel the first sensation of pain

The Shortened Disabilities of the Arm, Shoulder, and Hand Questionnaire (QuickDASH) consists of 11 questions that assess daily activities, symptoms, social function, work function, sleep, and confidence. There are 5 points, with 1 indicating no difficulty and 5 indicating impossibility. The score is converted to a 100-point scale, with 100 representing the highest level of disability

The QuickDASH Sports Module score will be used to assess the impact of arm, shoulder, or hand symptoms on the partipiants ability to perfom sport-related activites. This optional module includes 4 items focused on difficulty performing the selected sport or physical activity during the previous week. Each items is scored on a 5-point linkert scale. The final score is transformed to a 0-100 scale, where 0 indicates no disability and 100 indicates the graetest disability. All 4 items must be completed to calculate the module score.