Characteristics of trunk and lower limb alignment at maximum reach during the Star Excursion Balance Test in subjects with increased knee valgus during jump landing

RESEARCH ARTICLE Characteristics of trunk and lower limb alignment at maximum reach during the Star Excursion Balance Test in subjects with increased knee valgus during jump landing Kazuma Uebayashi ID1☯, Kiyokazu Akasaka2,3☯*, Akihiro Tamura4‡, Takahiro Otsudo2,3‡, Yutaka Sawada3‡, Yu Okubo2,3‡, Toby Hall5‡ a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Uebayashi K, Akasaka K, Tamura A, Otsudo T, Sawada Y, Okubo Y, et al. (2019) Characteristics of trunk and lower limb alignment at maximum reach during the Star Excursion Balance Test in subjects with increased knee valgus during jump landing. PLoS ONE 14(1): e0211242. https://doi.org/10.1371/journal. pone.0211242 Editor: Nathan Schilaty, Mayo Clinic Rochester, UNITED STATES 1 Department of Rehabilitation, Suzuki Clinic Orthopaedics River City, Chuo, Tokyo, Japan, 2 Saitama Medical University Graduate School of Medicine, Moroyama, Saitama, Japan, 3 School of Physical Therapy, Saitama Medical University, Moroyama, Saitama, Japan, 4 Department of Physical Therapy, School of Health Sciences at Narita, International University of Health and Welfare, Narita, Chiba, Japan, 5 School of Physiotherapy and Exercise Science, Curtin University, Perth Western Australia, Bentley, Australia ☯ These authors contributed equally to this work. ‡ These authors also contributed equally to this work. * Abstract Background The anterior cruciate ligament (ACL) is often injured during sport. The Star Excursion Balance Test (SEBT) has been used to evaluate ankle and knee stability of the supporting leg while reaching in eight different directions with the non-stance leg. We hypothesized that the SEBT might be useful in categorising ACL injury risk. The purpose of this study was to clarify the relationship between knee valgus alignment during single leg drop landing (SDL) and alignment of the trunk and lower limb during the SEBT. Received: October 21, 2018 Accepted: January 9, 2019 Published: January 25, 2019 Copyright: © 2019 Uebayashi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data can be found in the Figshare repository at the doi: 10. 6084/m9.figshare.7582235 or https://figshare. com/s/a5e8f02dbe673c629785. Funding: The authors received no specific funding for this work. Methods A three-dimensional motion analysis system was used to measure the trunk, hip and knee angles during SDL and the SEBT. Groupings were allocated based on 5 degrees of knee valgus angle during SDL. Independent t-test’s were used to identify differences in the trunk, hip and knee angles between the two groups. Results The knee valgus angles in the knee valgus group were greater than those in the control group in five directions of the SEBT (p < 0.05). In addition, the hip internal rotation angle in the knee valgus group was lower than that in the control group during two directions of the SEBT (p < 0.05). Furthermore, the knee flexion and trunk right rotation angles in the knee valgus group were lower than those in the control group in two directions of the SEBT (p < 0.05). Competing interests: The authors have declared that no competing interests exist. PLOS ONE | https://doi.org/10.1371/journal.pone.0211242 January 25, 2019 1 / 12 Characteristics of trunk and lower limb alignment at maximum reach during the Star Excursion Balance Test Conclusion Decreases in hip internal rotation, knee flexion and trunk rotation to the supporting leg during the SEBT might be considered as risk factors for non-contact ACL injury. Introduction Anterior cruciate ligament (ACL) injury is a serious and potentially devastating injury for athletes, and is common in many sports including soccer, basketball, handball and lacrosse. Injuries can be classified as either contact or non-contact with up to 70% classified as non-contact [1–5]. While non-contact ACL injury prevention programs have been widely studied, Distefano et al. suggested that ACL injury prevention programmes should be matched to the ACL injury risk of participants and designed along these characteristics [6]. Therefore, it is important to establish an evaluation method where the risk of non-contact ACL injury can be classified. One of the most significant mechanism’s for non-contact ACL injury risk has been widely considered poor alignment of the trunk and lower limbs [7 – 9]. Hewett et al., in their prospective study, reported that knee valgus when landing from a drop vertical jump increased the risk of non-contact ACL injury [10]. In addition, prospective studies have reported that increased knee valgus angle and knee abduction moment during landing were predictive of non-contact ACL injuries in female athletes [3, 10, 11]. Furthermore, knee valgus has been reported as a component of mal-alignment in non-contact ACL injury situations. Krosshuag et al. reported that greater knee valgus and less hip and knee flexion made athletes vulnerable to injury during landing and cutting [12]. Hewett et al. reported that greater knee valgus and greater trunk flexion to the supporting leg were factors placing athletes at high risk of non-contact ACL injury also during landing and cutting [13], while Koga et al. reported that less knee flexion and greater knee valgus during landing and cutting placed athletes at a high risk of injury [14]. Although dynamic knee valgus during landing is considered to be important for prediction of non-contact ACL injuries, various characteristics of trunk and lower limb alignment have also been confirmed to influence knee valgus at the time of injury. Therefore, an evaluation of these features including knee valgus might be helpful in planning injury prevention programs. Stability and distance reached during the Star Excursion Balance Test (SEBT) has been commonly used as an assessment tool to determine postural control and lower extremity injury risk [15–18]. In this test, the non-stance leg reaches as far as possible along eight lines drawn on the ground at 45 degrees to each other. Although there is some research reporting the relationship between the reach distance during the SEBT and injury risk after ACL reconstruction surgery [19,20], alignment of the lower limb related to non-contact ACL injury risk during this demanding task has not been investigated. We investigated whether altered alignment of the trunk and supporting leg during the SEBT and increased knee valgus alignment during single leg drop landing (SDL) might be associated and if so the SEBT might be helpful in identifying people vulnerable to non-contact ACL injury. Therefore, the purpose of this study was to investigate the difference in trunk and supporting leg alignment during the SEBT in people with and without dynamic knee valgus during a jump land (...truncated)