Ligaments sprain or tear
Anterior Cruciate Ligament (ACL)
One of the most common knee injuries is an Anterior Cruciate Ligament (ACL) sprain or tear.
Athletes who participate in high demand sports like soccer, football, tennis and basketball are more likely to injure their ACL.
Athletes carrying two copies of the COL5A1 variant were found significantly less prone to ACL injury.
The anterior cruciate ligament is one of four primary ligaments of the knee, situated in front of the knee. It forms a cross with the posterior cruciate ligament in the back of the knee, to prevents the tibia (shinbone) from sliding out in front of the femur (thigh bone), as well as providing rotational stability and control over the knee's back and forth motion.
Most Anterior Cruciate Ligament tears and sprains are non-contact injuries triggered by sudden twisting motion (i.e., when the feet are planted one way and the knees are turned the other way) or when landing from a jump.
Factors contributing to ACL injuries include ground hardness, age, gender and genetics. Teenagers and young adults are more prone to ACL injuries, probably due to ACL-challenging activity. As for gender, the average woman is almost three times more likely to injure the ACL than a man. Female soccer players were found eight times more likely for ACL injury than male soccer players. One reason for this gender difference is probably based on hormonal differences acting on ligament strength and stiffness.
Genetic predisposition is another factor contributing to ACL injury. Variants within the COL5A1 gene are associated with range of movement (ROM) and flexibility, as well as musculoskeletal injuries, including ACL tear. The COL5A1 gene encodes for the collagen a1 chain. This chain is a building block for the most prominent protein in connective tissue, including ligaments. COL5A1 plays an important role in regulating fiber diameter.
Homozygous for the COL5A1 'C' variant where found to be at reduced risk for ACL, while homozygous for the 'T' variant are at elevated risk.
To reduce risk of injury, work on flexibility, strength of hips and legs, balance, and improve landing technique. Make sure your knees are directly over your feet when landing, abruptly stopping, and changing direction. Don't let your knees collapse inward. Always warm up and stretch before games and practice, and cool-down gradually afterwards.
Ask your trainer for plyometric exercises, or 'jump training',which help build power, strength, and speed, and are recommended to reduce risk of ACL.