ACL ruptures are becoming more prevalent every year, increasing by about 5% each year. Worldwide, Australia has the highest rates of ACL injuries and young females are the most susceptible to this devastating injury. Even with surgical intervention and successful rehabilitation, less than one-third of athletes return to their pre-injury performance levels, a quarter go on to have a recurrent ACL injury and 50-90% will develop osteoarthritis of the knee in the coming 10-15 years post-injury.
These startling statistics and long-term effects these injuries have on a person’s life and sporting career make efforts to reduce prevalence and improve management of ACL injuries a key priority for those working with athletes of all levels.
What is the role of the ACL?
The ACL (anterior cruciate ligament) is band made up of dense connective tissue that travels from the base of the thigh bone (femur) to the top of the shin bone (tibia). The key role of the ACL is to prevent the shin bone (tibia) from slipping forward on the thigh bone. It provides 85% of the total resistance of this movement in the knee. It also prevents excessive rotation of the knee during heavy loading, as well as some resistance to bowing of the knee joint.
What causes an ACL injury?
ACL injuries most commonly occur in field or court sports in non-contact scenarios, when there is a powerful or forceful change of direction, deceleration, or an awkward landing. The most common position to observe an ACL injury is when the knee is bent, collapsing inwards and the torso is rotated away from the compromised knee.
What are the risk factors for experiencing an ACL injury?
- Prior ACL injury.
- Being female — possibly due to differences in anatomy, muscle strength and hormonal influences.
- Participating in certain sports, such as soccer, football, basketball, gymnastics, and downhill skiing.
- Poor conditioning
- Using faulty movement patterns, such as moving the knees inward during a squat.
- Wearing footwear that doesn't fit properly.
- Using poorly maintained sports equipment, such as ski bindings that aren't adjusted properly.
- Playing on artificial turf.
Strategies to prevent ACL injury:
Hip strength:
Athletes with a low level of hip adductor (groin) strength relative to hip abductor (glute) strength are more likely to experience an ACL injury in their career. A proper ACL prevention strength program should incorporate exercises that target the muscles of the groin. These muscles are particularly important in change of direction and jumping sports.
Jumping/landing technique:
Jumping or landing with a knee that drops in and over the supporting foot (knee valgus) significantly increases the risk of an ACL injury. This is due to a weakness in the hip, knee, or ankle. Females are typically more prone to this due to having naturally wider hips causing a larger angle at the knee. It is important to ensure good technique is used when training these aspects of your sport so that you can sub-consciously perform this movement correctly during competition.
Thigh and calf strength:
Typically, a strength program will heavily focus on muscles in the front of the thigh (quadriceps) and the upper calf (gastrocnemius). During take-off sports, these muscles significantly increase the force through the ACL if there is an imbalance of strength towards the surrounding muscle. A strength training program that focuses on consistently developing muscles around the knee, such as the glute muscles, back of your thigh (hamstrings) and the lower calf (soleus) can help to “de-load” the ACL and aid in prevention of injury throughout your career.
If you or a family member would like to learn more about ACL injury prevention or rehabilitation, the physiotherapists at Back In Motion Como would love to help!
Website: https://www.backinmotion.com.au/como
Phone Number: 9313 3414