Sex Differences in Landing Biomechanics and Postural Stability During Adolescence: A Systematic Review with Meta-Analyses

Background The adolescent `growth spurt' results in rapid growth of the skeletal system. It has been theorised that absence of a concomitant increase in muscular adaptations in female athletes may predispose them to an increased risk of anterior cruciate ligament injuries. Objectives To determine if sex differences exist in landing biomechanics and postural stability of adolescent athletes; with a further objective of determining if such differences are propagated during adolescence. Data sources The following databases were searched: MEDLINE, EMBASE, CINAHL, PEDro, PubMed, SPORTDiscus and Web of Science. Research papers were identified by including search terms for neuromuscular control, lower limb and pubertal development. Inclusion Criteria Studies were required to be written in English; report on biomechanical analyses; include landing or postural control tasks; be cross-sectional or longitudinal; and include healthy adolescent/pubertal subjects. Study Appraisal and Synthesis Methods A modified version of the Strengthening the Reporting of Observational studies in Epidemiology checklist was used to rate methodological quality. Meta-analyses were performed when more than one study reported on an outcome measure. Results Sixteen articles were included. The overall methodological quality of evaluated studies was low (mean score = 5.75/10 points). Adolescent females exhibited increased knee valgus with increasing maturity. There was no consensus on sex differences in postural stability. Conclusions With increasing maturation, females are characterized by increased knee valgus during landing tasks. To date, no research has longitudinally investigated postural stability development during adolescence in females, despite the importance of postural control training in injury prevention programmes. Therefore, further research on this topic is warranted.