RESUMO
PURPOSE: To investigate the 90° change of direction (COD) task in an extensive cohort of competitive healthy football players within the CUTtheACL study and to provide normative values and differences between males and females for full-body kinematics based on two-dimensional (2D) video analysis and scoring system. METHODS: One-thousand-and-two competitive football (soccer) players (age 16.3 ± 2.8 years, 264 females) were prospectively enroled. Each player performed three preplanned 90° COD tasks per limb. The 2D evaluation was performed through objective measures (collected through three high-speed cameras) of frontal and sagittal plane joint kinematics at the cut initial foot contact (IC) and maximum knee flexion angle. A previously published scoring system was adopted to measure the movement quality of the COD task. The scoring system included five criteria (limb stability [LS], pelvis stability [PS], trunk stability [TS], shock absorption [SA], movement strategy [MS]) ranked from 0/2 (nonadequate) to 2/2 (adequate) with a maximum score of 10/10. Normative data were provided for all the variables; statistical differences between male and female players were investigated (p < 0.05). RESULTS: A total of 6008 valid attempts were included. Frontal plane knee projection angle (FPKPA) at initial contact was 24.4 ± 9.8° (95th percentile: FPKPA > 40°). The total score was ≤4/10 in 71.2% of the trials, the lowest subscores were LS and PS. Female players showed different movement patterns with lower hip and trunk flexion both at IC and maximum knee flexion angle (p < 0.01, ES = 0.41-0.64). Female players also showed worse scores than males in SA, MS and total score (p < 0.01). CONCLUSION: Female players seem more prone to stiffer lower limb strategy and greater pelvis-trunk frontal plane instability than males. Clinicians could adopt normative data and sex-specific differences in players' movement techniques to improve ACL injury risk mitigation protocols. LEVEL OF EVIDENCE: Level IV.
RESUMO
For many years, we have been witnessing changes in what it takes to make a good orthodontist. A gradual shift has occurred from a manual to a technological approach, from professional intuition to image-based diagnosis and from craftsmanship to standardization of materials and procedures. Result-forecasting, reproducibility of outcomes, the transfer of, and agreement on, information and the delegation of functions, such are the future challenges our profession will have to meet. For many years already, information technology has been an indispensable partner of orthodontists to a point where we can now predict tooth movements in the occlusion and use this information in the complex mechanical manufacturing of the appliances required to achieve these displacements. Three-dimensional Information Technology (3D IT) is opening up new frontiers in this domain allowing the ever-greater use of industrially-manufactured appliances while respecting the biomechanical field. It has provided end-results which are totally positive for orthodontic patients, as was already the case in implantology and prosthetics.