How young girls change their landing technique throughout the adolescent growth spurt
Background: Despite the rapid musculoskeletal changes experienced by girls throughout the adolescent growth spurt, little is known about how their lower limb landing technique changes during this time.
Purpose: To investigate the longitudinal changes in the 3-dimensional lower limb kinematics, joint moments, and muscle activation patterns displayed by girls when performing a horizontal landing task throughout their adolescent growth spurt.
Study Design: Descriptive laboratory study.
Methods: A total of 33 healthy 10- to 13-year-old girls, in Tanner stage II, with a maturity offset of −6 to −4 months (time from peak height velocity) were recruited. According to her maturity offset, each participant was tested up to 4 times during the 12 months of her growth spurt (maturity offset: test 1 = −6 to −4 months; test 2 = 0 months; test 3 = 4 months; test 4 = 8 months). During each test session, participants performed a horizontal leap movement, during which ground-reaction forces (1000 Hz), lower limb muscle activity (1000 Hz), and kinematic data (100 Hz) were collected.
Results: Throughout the growth spurt, girls displayed a decrease in knee flexion (P = .028), increase in hip flexion (P = .047), increase in external knee abduction moments (P = .008), and decrease in external hip adduction moments (P = .003) during the landing movement.
Conclusion: During their adolescent growth spurt, pubescent girls displayed a change in the strategy with which they controlled their lower limb to land after performing a horizontal leap movement. This change in the landing strategy has the potential to increase the risk of anterior cruciate ligament injuries toward the latter stages of the adolescent growth spurt. Clinical Relevance: The outcomes of this research provide a greater understanding of the changes in the landing strategy used by pubescent girls throughout the adolescent growth spurt. This can assist in the development of screening tools designed to determine "at-risk" landing biomechanics during puberty.