Testing consisted of an  anterior drawer, Lachman  and pivot shift tests.

See "The ACL Tear:  Making the Diagnosis"

Instructor's Note:  The above testing may be difficult for the non-trainer to understand.  The important points the student needs to understand are 
1.   The testing is done to assess the proper movement of the knee  
2.  An athletic trainer can diagnose an ACL tear through this testing. 
The definitions of the following terms may be useful as the student studies the links pertaining to testing.

valgus
varus

The testing confirmed the trainer's suspicion of a tear in the ACL (anterior cruciate ligament).  Derrick was referred to an orthopedic surgeon. Physical exam showed swelling in the knee and hemarthrosis, The physician ordered an MRI (magnetic resonance imaging)  on the knee to confirm the diagnosis and assess the extent of the injury. 

5.  What is an MRI scan?  

6.  What health professional would perform an MRI scan?