Repeatability of Upper and Lower Body Force Plate Assessments in Canadian University Swimmers: Implications for...

The shoulder accounts for over 50% of injuries in swimming, making it the most injured body part. However, little research has examined shoulder girdle strength and how weakness or compensations may predispose swimmers to injury. Additionally, despite established muscle testing methods in other sports, there is a wide gap in the literature regarding strength testing in competitive swimmers, notably in the shoulder.

To establish the repeatability of the athletic shoulder (ASH) test, the ballistic push-up test, and the unilateral and bilateral countermovement jump (CMJ) test in male and female university swimmers.

Test-retest repeatability study.

University swimmers (n = 32; female: n = 18) completed strength tests on 2 occasions separated by a 60-minute rest period. Participants completed a standardized warm-up. The force plate testing battery consisted of isometric shoulder flexion (ASH test) at 180° and 135°, ballistic push-up testing, and bilateral and unilateral CMJ testing. Intrasession and intersession repeatability were assessed using intraclass correlation coefficients (ICCs) and coefficients of variation (CV).

All outcome measures for CMJ and ballistic push-up testing showed good (ICC = .80-.89, CV < 10%) or excellent (ICC > .90, CV < 5%) repeatability, although the ASH test demonstrated good-to-excellent relative repeatability (ICC = .87-.90) but greater absolute variability (CV > 10%).

CMJ and ballistic push-up testing on a force plate are suitable for athlete monitoring in competitive swimming. The ASH test demonstrated greater variability between sessions, highlighting the need for further evaluation prior to its integration into athlete monitoring assessments.