Functional Testing as Guideline Criteria for Return to Competition after ACL Rupture in Game Sports

A rupture of the anterior cruciate ligament (ACL) represents a severe injury in game sports, which is time and cost-intensive for athletes and clubs alike. As the lower extremities are subjected to multiple forms of strain and high demands are placed on them, athletes in games like soccer are affected more often than others. The point of return-to-play after such severe injuries is often preceded by long periods of rehabilitation. However, these periods often vary strongly. Multiple approaches are being discussed to estimate the point of return-to-play using functional test procedures. However, no general consensus has been reached regarding the relevant parameters, available test procedures and interpretation oftest results. Based on the requirement profile of soccer as a game sport, this review evaluates functional tests regarding the requirements strength, speed, agility, and movement quality as a coordinative feature. In addition to tests regarding individual forms of strain, this review also discusses combined test protocols. It describes performance variants and scientific quality criteria as well as the potential for practical implementation. While jumps can detect side-to-side asymmetries only through additional equipment such as force plates or markers, hop tests are more suitable for implementation and allow for an easier assessment of side-to-side asymmetries. Although several combined test protocols exist, none of them measures the entire requirement profile for games sports. To decrease the number of re-injuries after ACL rupture, a combined test protocol with a selection of the described scientifically reliable functional tests should be created and implemented as a return-to-competition guideline as well as pre-injury screening prior and during the season.