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FEATURE ARTICLES
ACL reconstruction return-to-soccer: Strength or Function? Budiman Pranjoto (Budi), BBiomedSc (FUHB), BPhty, PGDipPhty (OMT) Introduction Anterior cruciate ligament (ACL) injury is one of the more common and serious injuries sustained by football players, some even requiring surgical reconstruction (Bizzini, Hancock, & Impellizzeri, 2012). However, the rehab protocol for soccer players returning to sport after ACL reconstruction is not well defined (Bizzini, et al. 2012). A concern for athletes who have had an ACL reconstruction is the incidence of reinjury and surgical revision (Nagelli & Hewett, 2016). There are multiple aspects to return-to-sport after an ACL reconstruction, such as nutrition, general health, biomedical and psychological readiness. However, as physiotherapists, we generally “clear” an athlete to return-to-sport after they achieve good mobility (range of motion) with good strength and/or function relevant to their sport. For the purpose of this written assignment, we will primarily discuss rehabilitation goals and tests that are grounded around strength compared to function. This essay will discuss recent evidence around strength vs. function for return-to-sport for soccer players after an ACL reconstruction. I will discuss pros and cons for each of them and when strength or function is more
appropriate if one of them is superior to one another. For clarification, I define strength as a performance measure (e.g. peak torque) to produce an isolated movement (e.g. knee extension), while function is the ability to produce movement involving multiple joints in a functional pattern (e.g. hopping). When are strength or functional measures more appropriate? test.
Does strength affect function? While strength is defined as an isolated movement measure, it is important to consider that strength may result in better function as well. Schmitt, Paterno, and Hewett (2012) demonstrated this very well. Ninety
soccer players were involved in their study, 55 had undergone
ACL
reconstruction
and
35
were
uninjured. Maximum voluntary isometric contraction (MVIC) of quadriceps femoris was measured on both legs to give a quadriceps index for symmetry (involved/uninvolved × 100%). The 55 players with ACL reconstruction were then sub-grouped to those with high quadriceps index (≥90%), and low (<80%). The functional measurement outcome was a hop
The players that had ACL reconstruction and high quadriceps index performed similarly in the hop test compared to uninjured controls. However, the players that had ACL reconstruction but had low quadriceps
index (asymmetry), performed significantly worse in the hop test compared to uninjured controls. The result of this study brings evidence to what is intuitively understood that strength and functional outcome measures may not be two independent variables – but one can affect another. It is important that in this study, causality was not established between the two variables, correlation is found but strength does not necessarily lead to function and CONTINUED ON NEXT PAGE >>
