Identification of Athletes at Future Risk of Anterior Cruciate Ligament Ruptures by Neuromuscular Screening

Abstract

In the present study, currently noninjured female athletes with reduced EMG preactivity of the ST and increased EMG preactivity of the VL during side cutting were at increased risk of future noncontact ACL rupture. Our data indicate that a high-risk zone can be used to identify noninjured players at high risk of future ACL rupture. Consequently, individual preventive efforts can be introduced in time. However, large prospective studies are needed to confirm this finding before definitive clinical recommendations can be made.

Mapping current research trends on neuromuscular risk factors of non-contact ACL injury

“…The evidence on hamstring weakness as a risk factor for primary ACL injury remains poor, and is confounded by many other factors, including the fact that hamstring inadequacy may well be joint-angle and joint-angular velocity specific, or as mentioned above, that muscular capacity may well be dissociated from risk inducing activation patterns. In muscular activation pattern assessment, only two case-control studies Swanik, et al, 2004) found reduced activation of the semitendinosus combined with increased activation of the vastus lateralis during dynamic tasks as was found through prospective work (Mette K. Zebis, et al, 2009). These observations again suggest discrepancies between risk factors of a primary injury versus re-injury.…”

“…Of the 4 prospective studies observing the neuromuscular markers of ACL injury, 3 evaluated muscular capacity (comprising of isokinetic knee strength and H/Q ratio) as risk factor of non-contact ACL injury (Myer, et al, 2009;Söderman, Alfredson, Pietilä, & Werner, 2001;Uhorchak, et al, 2003), and 1 study evaluated muscular activation patterns (Mette K. Zebis, Andersen, Bencke, Kjaer, & Aagaard, 2009) (see Table 4). …”

“…This systematic review found only four prospective studies of which three studies looked into muscular capacity (Myer, et al, 2009;Söderman, et al, 2001;Uhorchak, et al, 2003) and only one study into muscular activation patterns (Mette K. Zebis, et al, 2009). From the studied cohorts, there were only a small number of individuals who incurred an injury with injury rates ranging from 1.3% to 9.0%.…”

“…With low rates of injury, suggestions for future work have been that risk of ACL injury would need to be studied in substantially larger cohorts than typically done but the cost associated to that is simply too high. The relatively higher incidence of injury in females has led to most cohort studies only involving females (Myer, et al, 2009;Söderman, et al, 2001; Mette K. Zebis, et al, 2009). …”

“…There were 20 studies in the last 5 years that addressed an association with motion pattern deficits, seeking opportunities to observe risk from motion analysis (Begalle, Distefano, Blackburn, & Padua, 2012;Dai, Sorensen, Derrick, & Gillette, 2012;Elias, Hammill, & Mizner, 2015;Greska, 2012;Hannah, Folland, Smith, & Minshull, 2015;Hughes & Daily, 2015;Kipp, et Zebis, et al, 2011). Whilst there is value in understanding how motion patterns relate to the underlying activation of muscles, it is important to keep in mind that the proposed risk due to imbalance in activation between medial hamstring and lateral quadriceps muscles was based on a limited sample (5 injuries), one particular task (side cut), and a very small window of preactivity observation (10 ms before touchdown) (Mette K. Zebis, et al, 2009), and that this has until now not been confirmed independently. With none of the associative studies strictly adhering to these criteria when measuring muscle activation patterns, any subsequent suggestions made around risk of ACL injury through a screening tool that is based on associations with the suggested muscle activation deficit should be interpreted with great care.…”