The Relationship Between 2d Knee Valgus Angle During Single Leg Squat (Sls), Single Leg Landing (Sll), and Forward Running

Abstract

Background: Two-dimensional (2D) analysis of knee valgus during common athletic screening tasks such as SLS has been purported to identify individuals who may be at a high-risk of ACL injury. There is limited literature exploring the relationships between joint motion during SLS and other athletic tasks associated with knee joint injuries, in order to evaluate the effectiveness of the SLS to identify athletes with hazardous knee motion in a range of athletic tasks.

The Relationship Between 2-Dimensional Knee-Valgus Angles During Single-Leg Squat, Single-Leg-Land, and Drop-Jump Screening Tests

“…Our results showed a strong relationship between FPPA in the SLS and SLL (r = 0.52) and moderate relationship between the SLS and DJ (r = 0.30). The relationship between SLS and SLL supports the findings of the preliminary study on by Atkin et al [15] , albeit the strength of the correlation is weaker in the current study. Atkin et al only studied eight women and therefore the stronger correlations may not represent those of the larger population.…”

“…Furthermore, Atkin et al [15] have shown a relationship in women between 2D FPPA in the SLS and running which demonstrates the potential clinical utility of 2D FPPA to screen female athletes using a simple SLS test.…”

“…2D analysis, more specifically frontal plane projection angle (FPPA), has been shown to be a valid and reliable method to quantify knee valgus motion during a number of screening tasks, including the SLS, SLL, DJ, side-step and side jump [12][13][14] . A small preliminary study of 15 recreational athletes found significant correlations in FPPA between the SLS, SLL and running in women but not men [15] , although the small sample means that further investigation with a larger sample is warranted.…”

Differences and correlations in knee and hip mechanics during single-leg landing, single-leg squat, double-leg landing, and double-leg squat tasks

“…For maximum knee abduction angles, maximum hip adduction angles, and maximum external knee abduction moments, most significant correlations were observed between the two landings and between the single-leg squat and landings. Atkin et al (2014) identified a moderated correlation for 2D knee abduction angles between a single-leg landing and a single-leg squat. Wallace et al (2008) found mostly small correlations for 3D knee abduction and hip adduction between a double-leg landing and a double-leg squat.…”

“…Based on previous studies (Atkin et al, 2014;Butler et al, 2012;Earl et al, 2007;Stensrud et al, 2011;Wang, 2011;Yeow et al, 2010Yeow et al, , 2011, a mediumto-large effect size was expected for the differences and correlations in kinematic and kinetic variables during landing and squat tasks. Assuming a Cohen's f of 0.25 for analysis of variance (ANOVA), a sample size of 24 was needed for a Type I error at the level of 0.05 to achieve a power of 0.8.…”