Methodological Report: Dynamic Field Tests Used in an NFL Combine Setting to Identify Lower-Extremity Functional Asymmetries

Abstract

Side-to-side differences in lower extremity biomechanics may be predictive of increased risk of lower extremity injuries in athletes. The purpose of this report is to provide field testing methodology for tests designed to isolate lower extremity asymmetry and to demonstrate the potential for these tests to provide reliable measures. Six athletes (3 females, 3 males), were tested on two consecutive days for activities incorporated into a replicated NFL combine setting. VHP and jump height were measured on a portable force platform as athletes performed maximum effort hops for 10 seconds. The MAT test incorporates two 90° single leg cuts during the trial and was measured as total time for completion. Intraclass correlations (within ICC [3,k], between: ICC [3,1]) were calculated. The VHP test had good to excellent within session reliability for peak power of both the right (ICC = 0.942) and left (ICC = 0.895) sides. Jump height showed excellent within session reliability for both the right (ICC = 0.963) and left (ICC = 0.940) sides. The between session reliability for peak power between jumps was good for the right (ICC = 0.748) and left (ICC = 0.834) sides. Jump height showed good to excellent between session reliability on the right (ICC = 0.794) and left (ICC = 0.909) sides. The MAT test also showed good reliability between days (ICC = 0.825). The results indicate that the VHP test provides reliable assessment of both within and between session jump height and power production. The MAT test also provides good reliability between testing days. Both the VHP test and the MAT test may be useful for clinicians to identify the presence of lower limb asymmetry and potential injury risk factors in athletic populations.

Effects of a full season on stabilometric Parameters of team handball elite athletes

“…In such cases, they displayed a high variation of postural stability outcomes and were more likely to suffer injuries during sport sessions (Hickey et al, 2009;Killen, Gabbett, & Jenkins, 2010;Wang et al, 2006). Sport researchers, strength and conditioning coaches, and athletic trainers could benefit from a known relationship between postural performance, lower limbs asymmetries and injuries (i.e.…”

“…It is generally recognized that the best performance in whole body tasks such as postural control is achieved by a symmetrical musculoskeletal system-relative to the two sides of the body (Cates & Cavanaugh, 2009;Hickey et al, 2009;. However, practicing a sport may exacerbate neuromuscular asymmetry, where an athlete may exercise one side of the body more often or intensely than the other (e.g., when consistently jumping or kicking with the same leg during matches or training sessions).…”

“…It is possible that athletes will be more asymmetrical with respect to their neuromuscular performance after a season of play, which could have a negative effect on the execution of motor tasks, particularly postural control. Unbalanced functional skills may increase risk for injury in athletes (Hewett et al, 2005;Hickey et al, 2009;Klein, 1970).…”

Return to sport following hip injury

“…The Agility Ttest looks at lateral motion deficits, acceleration/deceleration, and directional changes with cutting and running drills [27,33]. One trial for each limb is needed for comparison.…”

“…The push-off limb determines the limb tested. The modified T-test has been shown to have good reliability in National Football League (NFL) combine testing methods [33]. The zigzag run test measures agility, quick change in direction (cutting and turning), and acceleration/deceleration components of activity.…”