May I ask how your tear was diagnosed?

It appears that your problems would be related to the sartorius tear certainly. Whenever there is an injury/insult to a specific area there is maladaptive movement patterns, pain inhibition, and scar tissue/tightening in the area. In this case you may have an associated ligament sprain, but most likely spasm/tightness, and abnormal muscle tone. You may even want to get an MRI to confirm the consequences of the tear. I would be concerned about iguinal injury when you speak about stomach pain. Can be associated hip flexor problem or other issue