## 8 Risk Factors for Injuries  
Injury risk in young female soccer players stems from a multifactorial interplay of intrinsic and extrinsic factors, requiring targeted prevention strategies.  
Intrinsic factors, such as anatomical and biomechanical variables, play a central role. Females typically exhibit a greater Q-angle due to a wider pelvis, increasing lateral forces on the patella and predisposing them to knee valgus collapse during dynamic move ments, which contributes to ACL injuries [91]. This alignment also affects hip mechanics, heightening stress on the medial knee compartment and leading to overuse injuries like patellofemoral pain syndrome [92]. Additionally, weaker hamstrings relative to quadricep strength can reduce hamstring activation, elevating anterior tibial translation and the risk of ACL ruptures [93]. The hormonal profile of youth female players also influences injury susceptibility. Cyclic fluctuations in estrogen and relaxin levels affect ligament properties and neuromuscular control. For example, estrogen reduces ligament tensile strength and increases laxity, while relaxin compromises knee stability [94]. Studies indicate a 30-50% higher risk of knee injuries during the late follicular phase of the menstrual cycle [95]. Neuromuscular deficiencies further exacerbate injury risks. Proprioceptive deficits, typical during adolescence, impair joint stability under dynamic loads [96]. Female players perform worse in single-leg stability tests and exhibit higher ground reaction forces with less hip and knee flexion during landing, increasing anterior tibial shear forces [97]. Strength imbalances, such as weaker hamstrings compared to quadriceps, are linked to higher risks of hamstring strains, especially during high-speed running or deceleration [98]. Delayed activation of stabilizing muscles like the hamstrings and gluteus medius also heightens the likelihood of both muscle injuries and joint instability [99].  
Extrinsic factors also must be considered due to their implication in the injury risk profile of youth female soccer players. Training load and scheduling are central contributors; excessive volumes combined with insufficient recovery significantly increase the likelihood of overuse injuries. Sudden, unplanned increases in training intensity exacerbate fatigue, impairing neuromuscular control and elevating the risk of acute injuries. Research consistently underscores the adverse effects of chronic overload and inadequate recovery on young athletes [100]. Playing surfaces and equipment further influence injury risks. Artificial turf, due to its higher traction and altered force absorption, has been linked to increased rates of non-contact lower-limb injuries, especially during high-stress movements like cutting and pivoting. Improper footwear, such as cleats with longer studs or poorly fitted shoes, exacerbates biomechanical stresses on the foot, ankle, and knee, potentially increasing ligament and overuse injury risks. These factors are particularly critical in dynamic sports like soccer [101]. Psychosocial and developmental factors also contribute significantly. Competitive pressures and the pursuit of scholarships often drive young athletes to overtrain or play for multiple teams, compounding both physical and psychological stress [102]. During growth spurts, coordination deficits and temporary disruptions in neuromuscular control lead to biomechanical inefficiencies that heighten injury risk. These developmental changes highlight the need for tailored interventions to protect adolescent athletes during critical stages of maturation.