The ACL which is the anterior cruciate ligament, located towards the front of the inside of the knee structure is an important ligament which serves several purposes in the function of the knee. It stops any rotational movement between the two knee joints and also stops the knee going ahead of the shin bone, i.e. it keeps it alignment to form a true 90 degree angle. The posterior cruciate ligament has similar function but for the back of the knee.
How the ACL works in common sports and activities
The function of the ACL can be highlighted and explained taking an example of the forces and movement patterns occurring in for a typical soccer player who face directional and linear forces throughout a soccer game.
Linear forces – any sport that requires basic straight line running will require an intact ACL to stop the shin bone protruding ahead of the knee, if this occurs from a weak ACL or damaged ACL it then in turn will stress the other three ligaments by literally pulling on them away from their normal range.
Directional changes and forces
Once again the soccer player is perfect to highlight the stress and forces that go into the knee and subject the ACL. On a sudden turn and stop from running this would could three major forces stressing the ACL:
1. Dynamic valgus (lateral or side movement)
2. Internal rotation – (twisting of the knee)
3. Interior translation (shearing of the knee moving forward)
These forces can be responsible for tearing or injuring the ACL and weakened or imbalanced surrounding muscles will make this more likely. Injury prevention should involve strengthening of the surrounding leg muscles to further add support to this area.
Jumping stress
Perhaps more relevant to volleyball, basketball and other such sports particularly track and field and the traiing involved which creates stress for the ACL especially when body weight is dynamically shifted from the back to the front of the knee from a deep squat position to full extension. Again if the ACL is weak or damaged this stresses the secondary supporting ligaments and further injury can occur.
Use of support brace for ACL protection and prevention
It is difficult to give a true measure o how much a brace can help with ACL prevention injuries, but using a knee brace with custom compression is understandably going to help with any further injury occurring, but there must be a functionally adequate firm support that can assist in this. A study has been published which gives good data on prevention:
The best study to date of prophylactic knee braces and ACL injury remains a prospective, randomized study of 1396 cadets playing intramural tackle football at the U.S. Military Academy (Sitler et al. 1990). This study showed that prophylactic knee brace use did not significantly decrease the severity of ACL and MCL injuries.
Study showing effect on ski ACL injuries:
A prospective study of 180 ACL-deficient skiers, identified from screening of 9410 professional skiers, showed a higher risk of knee injury in skiers who did not wear a functional knee brace compared to those who wore functional knee braces (risk ratio of 6.4, based on a total of 12 injuries) (Kocher et al. 2003).
Full citation and further reading: understanding-and-preventing-noncontact-acl-injuries
The EX-701 for ACL prevention
After understanding what the ACL is subjected and the needs of sports people to primarily be in a state of fitness that gives them reduced injury risk from strength and conditioning the next step to prevention is bracing and support. However due to the need of an athlete to be mobile not restricted and still have a protected element to wearing a support brace the choice of such a brace becomes very important.
based on neoprene open patella designs the EX-701 id a good choice for prophylaxis of ACl and other knee injuries because of the advanced features which are perfect for sport:
1. Secure anchoring to the thigh and calf Preventing knee brace from slipping. This should not be overlooked of the many neoprene knee braces on the market there are far too many that do not stay put on exercise, which means by definition it cannot be providing protective support if it can’t stay put. The unique 4-way independent strapping system ensures minimal slipping if not any.
2. Secure patella compression and isolation. The patella is also vulnerable and the way the two cross-over smaller straps integrate with the design of the EX-701 means that the total compression is much more sophisticated and functional than regular 3 strap generic knee brace designs which will not have the same level of firm compression.
3. Medial and lateral ligament supports. If you understand that weak muscles and weak a weakened acl will cause the surrounding supporting ligaments to be stressed further it makes sense to have additional support for the lateral supportive structures. The combination of the double lateral stabilizers, the 2 cross-over straps and the large anchor straps create a unique almost shell or cocoon type compression comfortably encasing the entire knee to give very comfortable and positive feedback compression.
It is quite hard to really show case the difference between a 3 strap generic knee brace which will simply collapse and can easily be scrunched into one’s hand vs a functionally advanced design which is going to give the support where you need, if you have made it this far into the article it would make good sense to watch the video below which will help bring to life the differences that exist between the EX-701 and other neoprene knee braces on the market.
The EX-701 knee brace can be purchased here on amazon.co.uk