Competitive Swimming and Shoulder Adaptations: The Role of Stroke Specialty in Adolescent Swimmers

Muscle strength was assessed with break test by using hand-hold dynamometer (Jamaar Hand Dynamometer, USA). Assessments were applied for both shoulders and 3 times for each position. Shoulder flexion, extension, abduction, full-can, glenohumeral IR and ER, upper, middle and lower trapezius, serratus anterior muscle tests were applied. GH ER/IR ratio was calculated as well (21-26). Measurements were recorded in Newton (N).

Passive Range of Motion (PROM) of both shoulders was assessed using a digital inclinometer (Get My ROM, version 1.0.3 for iOS; Interactive Medical Productions, Hampton, NH, USA). Shoulder internal rotation (IR), external rotation (ER), and total-rotational ROM were assessed (ICC = 0.92-94). Shoulder IR and ER PROM were obtained with the participant lying supine on a standard examination table, with the shoulder initially abducted to 90° with 0° rotation and the elbow flexed to 90° with neutral pronation/supination. In addition, Total-rotational ROM was calculated by summing the IR and ER ROMs average degrees of each shoulder.

Digitized 2 anatomical landmarks representing the length of the pectoralis minor. These 2 points were the medial-inferior angle of the coracoid process and just lateral to the sternocostal junction of the inferior aspect of the fourth rib. Measurements of pectoralis minor muscle length was taken with tape measure (ICC = 0.96). Because of height and muscle length variability among subjects, a normalization index was developed. The pectoralis minor index (PMI) was calculated by dividing the resting muscle length measurement by the subject height and multiplying by 100.

For proprioception testing, participants attempted to reproduce 45° ER angle. Participants were positioned as lying supine with arm abducted to 90°, elbow flexed at 90°. The ''Get My ROM'' digital inclinometer was used to measure the angles; the iPhone was securely attached to participants forearm using a strap with the screen facing the tester (ICC = 0.87-89). The participant was instructed to close their eyes by using an eye patch throughout testing. The arm was passively rotated to 45° ER and held in this position for 3 seconds. The participant was asked to remember this position. Following the return to neutral the participant was asked to actively return the arm back to the angle shown. The amount of degrees away from 45° was recorded.

Participants were positioned supine with both shoulders flush against a standard examination table. The tester stood at the head of the examination table toward the head of the subject and positioned the test shoulder and elbow in 90 of both abduction and flexion. To measure GH horizontal adduction, The ''Get My ROM'' digital inclinometer was aligned with the ventral midline of the humerus. The angle created by the end position of the humerus with respect to 0 of horizontal adduction was then recorded as the total amount of GH horizontal adduction motion (ICC = 0.79).

Each participant performed 5 repetitions of bilateral, active, weighted shoulder flexion and bilateral, active, weighted shoulder abduction (frontal plane) while they were observed from the posterior views. First of all, the scapula was observed while participants in rest and then weighted shoulder flexion and abduction movements from the posterior views. Kibler et al. reported the reliability of a visually based classification system for scapular dysfunction that defined 3 different types of motion abnormalities: Type 1 = inferior angle prominence, Type II = medial border prominence and Type III = excessive superior border elevation. Normal, symmetric scapular motion was considered Type IV (ICC = 0.32-42).

KJOC has been designed specifically as a subjective assessment tool to measure functional status of the upper extremities in overhead athletes. The KJOC was translated from English to Turkish to enable use of questionnaires in Turkish overhead athletes by Turgut et al. KJOC was used to measure functional status of the upper extremities in competitive adolescent swimmers and the scores compared in different stroke specialty among the swimmers in this study.