How ACL Injuries Are Detected on the Field
You see an athlete go down and clutch his knee. The sports medicine staff sprints out and immediately begins assessing the situation, grabbing, bending and pulling the seemingly injured knee. It may look painful, but Lachman's Test is a necessary evil to determine whether an ACL injury has occurred. (Learn more about knee injuries.)
In simple terms, most ACL injuries are caused by sliding or rotating the thighbone in relation to the shinbone. Extreme force is placed on the ligaments, resulting in a sprain or a complete tear. No athlete is immune, but the chance of this happening can be reduced with a proper strength and conditioning program. (See 3 Exercises to Prevent ACL Injuries.)
Immediately after an injury, there may be no visual sign except minor swelling (which increases over time). However, the sports medicine staff must do a preliminary evaluation so they can take the proper course of action and prevent the athlete from suffering further damage.
One of the most common tests is called Lachman's Test. It is designed to detect an ACL injury by checking anterior joint laxity. Here's how the test is conducted:
- The athlete lies down and extends both legs.
- A medical staff member bends the uninjured knee to about 20 degrees of flexion.
- The medical staff member grasps the femur (i.e., thighbone) with one hand.
- With the other hand, he or she grasps the tibia (i.e., shinbone) with his or her thumb positioned on the tibial tuberosity (i.e., the bony bulge at the top of the tibia).
- The medical staff member then pulls and pushes the tibia forward and backward on the uninjured leg to assess the athlete's normal joint laxity.
- He or she then performs the same procedure on the injured leg. If more joint laxity exists, or the athlete feels pain, an injury has occurred.
This test is important for assessing an injury, but it's also important to have determined an athlete's needs before an injury to get a baseline. Baseline information can be used to identify issues and possibly take corrective action before an ACL injury occurs.
Watch this video from SMARTER Team Training for more info on Lachman's Test:
Editor's Note: Coach Taylor has developed the SMARTER Team Training Audio Interview Series, dedicated to promoting critical thinking, reason and public understanding of prudent, purposeful and productive strength and conditioning practices for clients and athletes. Listen to episodes featuring some of the best experts in the fields of strength and conditioning, personal training, sports nutrition and sport psychology here.
Photo: Orthopaedics One