Author Identifier (ORCID)
Paul Comfort: https://orcid.org/0000-0002-1131-8626
Abstract
Background: The aim of this study was to determine the impact of knee angle variability on force production outcomes during the single-leg isometric long-lever bridge, thus providing monitoring guidelines for testing rigor with direct implications for feasibility across a variety of high-performance sporting environments. Methods: Thirty men (age: 19.4 ± 1.3 years; height: 179.8 ± 6.3 cm; body mass: 80.4 ± 10.3 kg) and 14 women (age: 20.0 ± 1.3 years; height: 166.9 ± 7.2 cm; body mass: 64.4 ± 7.4 kg) all of whom were Division 3 athletes with no recent injury history volunteered to participate in the study. All participants completed three testing sessions over five days in randomized order, with knee flexion angles of 15°, 30°, or 45° degrees. Each session consisted of three unilateral maximal voluntary isometric contractions (MVIC), with the athlete’s heels positioned on force plates, shoulders elevated on a 15.24 cm box, and hips secured using a rigid barbell. All data was analyzed to assess net force production comparisons between knee angles at 50, 100, 150, 200, 250 ms and peak force (N). Results: Large variance in force outputs were observed ranging between 0.30 and 0.82 (male ηp²), and 0.52–0.76 (female ηp²), and significant differences observed between all knee angles (p < 0.05). Pairwise comparisons revealed effect sizes ranging between small-large for males (Hedge’s g = 0.27–1.84) and moderate to very large for females (g = 0.51–2.18) across individual force-time points. Conclusions: These findings indicate that the knee angle must be rigorously controlled when performing the single-leg isometric long-lever bridge to mitigate unwanted variability and to accurately assess the intended musculature, especially for longitudinal monitoring.
Keywords
Force plates, hamstring assessment, isometric strength, long-lever bridge, performance monitoring
Document Type
Journal Article
Date of Publication
12-1-2026
Volume
18
Issue
1
Publication Title
BMC Sports Science, Medicine and Rehabilitation
Publisher
Springer
School
School of Medical and Health Sciences
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Comments
Sundh, A. E., Ripley, N. J., Lamb, A., Cantwell, C. J., & Comfort, P. (2025). The impact of testing-parameter variability on force production in the isometric single-leg long-lever bridge: Implications for training and testing rigor in sporting environments. BMC Sports Science Medicine and Rehabilitation, 18. https://doi.org/10.1186/s13102-025-01407-9