A multidimensional evaluation of various isometric posterior chain strength assessments: Comparative force production characteristics, administrative feasibility, and athlete-reported experience

Isometric posterior chain strength assessments are increasingly employed in high-performance sports for benchmarking and fatigue monitoring, yet little is known about how practical implementation factors influence protocol selection. The aim of this study was to examine the feasibility, practicality, participant perceptions, and reliability of four commonly used isometric posterior chain assessments, the long-lever bridge (LLB), standing 90:20, supine 90:90, and supine 30:30. Thirty-seven NCAA division II athletes (19 females: age = 20.1 ± 0.9 years, height = 166.7 ± 5.2 cm, body mass = 67.0 ± 12.1 kg; and 18 males: 19.7 ± 1.2 years, height = 178.9 ± 6.6 cm, body mass 79.8 ± 8.1 kg) completed all four protocols in randomized order across four sessions. Protocol duration, athlete-reported perceptions (effort, comfort, soreness), and within-session reliability of force-time characteristics were assessed. Protocol duration ranged from 2:30 to 3:20 min, with the LLB requiring the longest setup time. The supine 90:90 was consistently rated the easiest and most comfortable assessment, particularly among female athletes, while the LLB was rated as the most demanding. Peak force demonstrated excellent reliability across all protocols (intraclass correlation coefficient lower bound 95% confidence interval > 0.90, coefficient of variation < 5%), though rapid force production ranged between poor-good reliability at early force-time points (50–250 ms). These findings demonstrate that no single protocol optimizes all criteria simultaneously. Protocol selection should balance measurement quality with practical feasibility, guided by the primary monitoring objective and whether sustained athlete compliance or comprehensive force production profiling is prioritized.