Background Young female athletes involved in high-speed cutting and change-of-direction sports are particularly susceptible to anterior cruciate ligament (ACL) injuries. Little is known if maturational changes in cutting technique contribute to the increased injury risk.

Objective To examine longitudinal changes in cutting kinematics in female athletes as they matured through puberty.

Design Longitudinal cohort study

Setting Biomechanics laboratory

Patients (or Participants) One-hundred and seventy-two healthy high-school athletes were tested while in at least two different pubertal stages (pre-, mid-, post-pubertal).

Interventions (or Assessment of Risk Factors) Trunk, hip, and knee sagittal, frontal and transverse plane range-of-motion, peak angles, and angles at initial-contact during an unanticipated 45° cut measured with a laboratory-based optoelectronic motion capture system. Pubertal stages were defined by Tanner Stages.

Main Outcome Measurements Changes in trunk, hip, and knee kinematics as girls mature across puberty (pre-to-midpubertal, pre-to-postpubertal, mid-to-postpubertal).

Results As girls matured through puberty, they displayed a decrease in sagittal-plane hip (1.6–4.4°, p≤0.01) and knee range-of-motion (ROM) (2.7–2.9°, p≤0.01), and decreased peak hip (2.9–3.2°, p≤0.02) and knee flexion angles (2.5–2.9°, p≤0.01), which is indicative of greater quadriceps dominance. Peak knee abduction angles also increased as girls progressed through puberty (0.9–1.4°, p≤0.006), suggesting greater ligament dominance. In terms of trunk dominance, there were mixed findings with a decrease in trunk frontal- (2.5–5.7°, p<0.01) and sagittal-plane ROM (1.4–2.0°, p≤0.05), but an increase in trunk transverse-plane ROM (2.8–3.6°, p≤0.01) observed as girls mature. Other significant changes in cutting technique were decreased peak trunk flexion (3.8–7.8°, p≤0.01), and decreased hip flexion (2.9–3.3°, p≤0.01) and knee flexion angles (2.0–3.0°, p≤0.02) at initial contact, suggesting a more upright and stiffer cutting posture.

Conclusions As girls mature through puberty, they display a change in cutting strategy characterized by greater quadriceps and ligament dominance. Ameliorating these kinematic changes throughout maturation may further reduce ACL injuries in this high-risk group.