Not everyone can get the title of cross friend. If you want to have this "honor", you must go through various physical examinations and tests. I believe everyone has heard it from the doctor. Passed similar Lachman test, drawer test, etc., but what exactly does the Lachman test do?

The most detailed answer is in this article.

Purpose of the experiment:

The Lachman test is used to detect anterior cruciate ligament (ACL) injury or tear.

Origin of the name:

This test was invented by John Lachman, an orthopedic surgeon at Temple University in Philadelphia, and is named after his Naming.

Common Lachman test process (1):

1. The patient lies flat, legs straight, and muscles relaxed.

2. The doctor places the patient's injured leg in a position where the knee is bent at about 20-30°, and puts his knee under the patient's thigh. .

3. The doctor uses one hand to stabilize the distal femur near the joint line on the front side of the knee joint while palpating the joint line; the thumb of the other hand is placed on the proximal tibia, and the remaining fingers grasp the tibia close to the knee Posterior side of the joint line.

4. The doctor will apply a rapid force from back to front through the tibia

Common Lachman test process (2):

1. Patient Lie flat on your back with your legs straight and your muscles relaxed.

2. The doctor slowly and gently bends the patient's knee to an angle of about 20 degrees. The doctor can rotate the patient's leg so that his knee points outward.

3. The doctor places one hand on the lower thigh and the other hand just below the bend of the calf.

4. The doctor gently but accurately pulls the patient's calf forward and uses the other hand to keep the patient's thigh stable.

Positiveness and significance:

The tibia is obviously moved forward, indicating a rupture of the anterior cruciate ligament. Conversely, for posterior cruciate ligament rupture

How is the Lachman test scored?

The Lachman test uses two main benchmarks to score your ACL injury:

How much did the tibia and knee move during the test?

If the movement exceeds the normal range, you may have an ACL injury.

It can also help doctors determine whether other tissues are injured and whether the joints are stable.

During testing, how secure did the ACL feel when moving through its normal range of motion?

If the ACL does not have a stable endpoint when it reaches the end of its normal range of motion, it is possible to become injured or torn.

The doctor may also perform a Lachman test on the patient's other leg for comparison.

By looking at both legs of the patient, the doctor can grade the damage:

Normal: No obvious damage, especially compared to the other leg.

Mild (Grade 1): The injured leg has 2 to 5 millimeters more range of motion than normal compared to the other leg.

Moderate (Grade 2): The injured leg has 5 to 10 millimeters more range of motion than normal compared to the other leg.

Severe (Grade 3): The injured leg has 10 to 15 millimeters more range of motion than normal compared to the other leg.

What conditions does the Lachman test help diagnose?

The Lachman test is the most common method for diagnosing anterior cruciate ligament injuries.

Is the Lachman test the same as the anterior drawer test?

The anterior drawer test (ADT) is often performed at the same time as the Lachman test to help confirm the diagnosis of ACL injury. Doing both tests usually produces more accurate results than doing both tests separately.

How accurate is this test?

Many studies have shown that the Lachman test is very accurate in diagnosing ACL injuries, especially when used with ADT or other diagnostic tools.

A 2013 study of 653 people with ruptured ACLs found that the Lachman test had a success rate of 93.5 percent, and was only 1 percent less accurate than the ADT.

A 2015 survey found that the success rate was approximately 93%.

Scar tissue that forms on the ACL can cause false positives. This can make the leg appear to be restricted from its normal range of motion when it is actually just scar tissue holding the leg back.

What advice might you receive about the next steps after diagnosis?

1. Reduce swelling: Rest, apply ice, and do sit-ups to relieve swelling after injury.

2. Wear a knee brace to stabilize the knee and reduce pressure on the anterior cruciate ligament.

3. Receive physical therapy, preoperative rehabilitation or conservative treatment rehabilitation

4. Make an appointment for the next review time or surgery time

Friendly reminder: lachman test , the drawer experiment, these tests, fork friends, please do not try to do it yourself...this leg has suffered enough with us, do not artificially increase the risk of injury.

Find professionals to implement it