Introduction The presence of neuromuscular imbalance (Hewett, 2010) or functional malalignment may be part of the increased rate of adolescent knee injuries, specifically the anterior cruciate ligament (ACL). Abnormal lateral trunk and knee abduction moment are possibly linked to the biomechanical mechanisms resulting in ACL injuries (Hewett, 2010). Prevention may therefore depend on identifying these potentially injury risk factors. Screening tools must thus include patterns of typical movements in sport and leisure time activities, consisting of high-load and multi-directional tests, focusing on functional alignment. In large epidemiological studies these tests must only require a minimum of time and technical equipment. Objective The purpose of the study was to accomplish a systematic review of screening tests for identification of adolescents at increased risk of knee injuries, focusing on functional alignment of the trunk and lower extremities. Methods An electronic database search was performed accessing Pub- Med and Embase from 2000 to 2011. Eligible studies assessing functional alignment screening of trunk and lower extremities in children or adolescents (10-18 years old) were included. Hand searching of all reference lists of the included studies was performed. Laboratory settings were included as reference tests, but studies with the primary test requiring force plate, 3D analysis or other technical device were excluded. The QUADAS score (Whiting, 2006) was used to evaluate methodological quality. Results Of 1475 articles, 28 articles met all inclusion criteria. Only 3 studies assessing functional alignment were identified. The Drop Jump Test showed moderate to excellent reliability (Kappa .75-.85) of clinically assessed knee valgus motion in detection of knee midline collapse in the frontal plane, (three raters, n=40). However, the sensitivity was inadequate, ranging from 67-87% compared to 3D analysis. Concurrent validity during Drop Jump showed a correlation between assessed knee valgus motion and 3D measurements of r = .87 (n=20). Reliability of The Single-limb mini squat test was fair to moderate (Kappa .48- .57) corresponding to 76-79% agreement when evaluating the medio-lateral knee position during dynamic movements (two raters, n=33). No studies incorporated clinical assessment of trunk alignment. Conclusion Since only 3 studies were identified including screening tests of knee alignment, there is a further need to evaluate reliability and validity of real-time functional alignment tests, before the can be used as screening tools for prevention of knee injuries among adolescents. Still the next step in this systematic review is to evaluate the quality and feasibility of the three identified tests.
Real-time Screening Tests for Functional Alignment of the Trunk and Lower Extremities in Adolescent – a Systematic Review, 2012