# Lower-Limb Flexibility Profile in 142 Competitive Female Football Players: A Cross-Sectional Study
## 4 Discussion
For example, a female football player who achieves a ROM of 70\({}^{\circ}\) for hip flexion with the knee extended, which is below average, can be set a ROM target of 73\({}^{\circ}\) to reach the lower end of average. Once this value is reached, a new benchmark can be set, e.g., a long-term ROM target of 82\({}^{\circ}\) to correspond to the lower ROM value above the average. Thirdly, benchmarks can be set for young women's football players (formative stages) who aspire to a career as First Division League players. For example, if a female football player achieves 25\({}^{\circ}\) in the hip extension range of motion (ROM) test with the knee relaxed, she would be classified at a \"Good\" level and could potentially improve to \"Excellent\", thereby enhancing her athletic performance [37; 38; 39]. In a sample of 43 young male football players (aged 14 to 18 years), those with greater hamstring flexibility, as measured by the hip flexion with knee extended ROM test, outperformed their peers with lower flexibility in acceleration and sprint tests (5 m, 10 m, and 20 m), the countermovement jump, Balsom agility test, and take-off speed [38]. The hip flexion with the knee extended ROM may be a determining factor for skill performance, as shown by the deficits in kicking in football players with tightness hamstrings compared to athletes with greater hamstring flexibility [39]. [PERSON] et al. [37] have shown that increasing the ROM of the ankle joint through a 4 week soleus stretching programme leads to significant improvements in the Y-balance, drop jump, and Illinois agility tests. On the other hand, if a player reaches a value of 6\({}^{\circ}\), she has a level of \"Poor\" and increases the risk of a football injury. [PERSON] et al. [40], for example, supported this notion by examining hip ROM (flexion, extension, abduction) in 167 male and female student athletes aged 13-17 years from Japan and reported that lower values of hip internal rotation range of motion [\(\leq\)35\({}^{\circ}\)] and external rotation range of motion [\(\leq\)46\({}^{\circ}\)] were associated with ACL injury. [PERSON] et al. [5] found that internal rotation of the hip with a flexed knee ROM of \(\leq\)44\({}^{\circ}\) and hip extension with the knee relaxed ROM asymmetry of \(\geq\)5\({}^{\circ}\) were discriminatory for ACL rupture detection in 95 female football players aged 14 to 33 years. [PERSON] and [PERSON] [41] found that reduced hip flexion and internal rotation on the dominant side of players may increase the risk of lower limb injury in 32 female professional football players (age 23 \(\pm\) 3.60 years). In contrast, there is a significant relationship between an increased incidence of football injuries and increased joint laxity in 123 senior female football players (elite n = 32 and non-elite n = 91) [42]. Emerging evidence shows that limited ankle dorsiflexion may lead to compensatory landing patterns, such as increased knee valgus and anterior tibial translation, which elevate ACL strain during dynamic tasks [43]. These compensations are particularly concerning in female football players, who already present a higher incidence of ACL injuries. Therefore, addressing joint ROM limitations, especially at the ankle and hip, may be crucial for developing targeted prevention strategies in this population. On a quantitative level, all the different stretching techniques can improve the extensibility of the muscles and the ROM of the different joints, such as ballistic stretching, dynamic stretching, active statics stretching, proprioceptive neuromuscular facilitation, eccentric flexibility training or passive statics stretching. However, each stretching technique has additional benefits related to the time of application and the procedure of the stretching technique. Ballistic stretching and dynamic stretching are techniques that are recommended during the warm-up.