A postural program to reduce dynamic knee valgus during single-limb squatting in young athletes: a preliminary study.

BACKGROUND: Dynamic knee valgus (DKV) is an undesirable multi-joint movement pattern associated with anterior cruciate ligament injury and patellofemoral pain syndrome, especially in sport activities. We assessed DKV in young athletes who followed a postural program to reduce a posterior rigidity mostly attributable to the tightness of hamstring muscles. METHODS: We considered 12- to 18-year-old athletes that followed a six-week program simply based on hamstring stretching and abdominal muscle activation/strengthening. DKV was assessed during a single-limb squat and the frontal plane projection angle (FPPA) between the femur and tibia was considered. RESULTS: Sixty-six athletes with a significant DKV (FPPA≥10°) were identified. Twenty-one subjects exhibited the considered rigidity profile and completed the intervention program. The mean reduction of the FPPA after the intervention was 8.1±7.9°, significantly asymmetric by about 3° (P<0.005) and skewed towards larger negative differences. The average change from the initial condition of -37±25% was statistically significant (P=1.7 x10-6). CONCLUSIONS: This preliminary result suggests that working on enhancing posterior muscle chain flexibility could be effective in reducing DKV in young athletes with a marked tightness of hamstring muscles. Moreover, this simple postural program can be a candidate for inclusion in sport training as a protective strategy against knee injuries.

The influence of lifestyle factors on miRNA expression and signal pathways: a review.

The term 'lifestyle' includes different factors that contribute to the maintenance of a good health status. Increasing evidences suggest that lifestyle factors may influence epigenetic mechanisms, such as miRNAs expression. The dysregulation of miRNAs can modify the expression of genes and molecular pathways that may lead to functional alterations. This review summarizes human studies highlighting that diet, physical activity, smoking and alcohol consumption may affect the miRNA machinery and several biological functions. Most miRNAs are involved in molecular pathways that influence inflammation, cell cycle regulation and carcinogenesis resulting in the onset or progression of pathological conditions. Investigating these interactions will be pivotal for understanding the etiology of pathologic processes, the potential new treatment strategies and for preventing diseases.