Question

Which of the following choices best describes the proper order of steps for performing the Lachman's test?

1) Apply anterior force to the tibia while stabilizing the femur
2) Observe for excessive anterior translation of the tibia
3) Assess the quality of the endpoint
4) Repeat the test on the opposite knee
5) Compare the results bilaterally

Answer 1

Lachman's test evaluates the integrity of the ACL by stabilizing the femur, applying anterior force to the tibia, observing tibial translation, assessing the endpoint, and comparing results bilaterally. The ACL prevents the tibia from sliding forward, while the PCL prevents backward sliding.

Step-by-step explanation:

The proper order of steps for performing the Lachman's test, which is used to evaluate the integrity of the anterior cruciate ligament (ACL) in the knee, is as follows:

1. Stabilize the femur.
2. Apply an anterior force to the tibia.
3. Observe for excessive anterior translation of the tibia.
4. Assess the quality of the endpoint.
5. Compare the results bilaterally by repeating the test on the opposite knee.

The anterior cruciate ligament (ACL) resists hyperextension and keeps the tibia from sliding too far forward in relation to the femur. In contrast, the posterior cruciate ligament (PCL) prevents the tibia from sliding too far backward. Common causes of ACL injury include forceful blows to the knee that produce hyperextension or twisting motions during activities such as running, which can both twist and hyperextend the knee.