I'm not reading other replies.
Torn muscle...unless they have other accreditations, or unless you're in a state that allows it, most a DC could do is tell you to ice it, and to see someone else if it keeps hurting.
Chiropractic is about vertebral subluxations, which means a slight movement out of place, causing problems in the nerves and nervous system, which means the body isn't communicating correctly. Most of the time the body can solve this problem on its own, but subluxations happen when the body can't.
Traditional cultures have always had methods of "cracking" spines to feel better. But back in the 1800s (same year that xray was discovered) __ Palmer (my chiro history is failing me can't remember his first initials...think the elder was D.D. and the younger was B.J.), through a change meeting, discovered that it isn't all about symptoms, but can be "bigger". He had met a janitor who had been deaf for years, the janitor told him it had been a sudden onset while lifting something, and the last thing he heard was a pop in his neck. Palmer asked if he could do something with the guy's neck, he did, and the janitor got his hearing back. He then thought it was a "cure for deafness", but while marketing it as such realized that it wasn't a cure for all deafness...but that doing those moves on peoples' necks could help OTHER conditions. It all depended on the person and what was going on with them...with their subluxations had caused in them.
Thus it became something more than allopathic (have a symptom? here's a solution) and became more holistic, in that the subluxation itself is the problem, and the body knows what it can do once the subluxation is fixed.
Now, there have been tons of studies showing that it is better for "back pain" than other things, so that's important for many people. And there are many DCs who practice in that way, and that's good for them and for their patients!
My mom "discovered" chiropractic when I was a young teen. I was having some problems with shin splints and allergies, and she finally dragged me into see her DC. Now, this is not in my state's scope of practice, but it was for CA, and she did some sort of knee manipulation, and my shin splints went away. Turns out my leg bones and patella were out of alignment, which was causing the shin splint pain, and so by fixing that she fixed my symptom. That was GREAT. But the next thing she did was an adjustment on my thoracic vertebrae, and within that, or maybe 2, visits, my allergies were gone. I had been doing allergy shots for over a year and had had NO change in allergies (they were the worse allergies one can imagine, completely impacting my school life and my driving, and social life, too)...so this immediate difference was amazing.
I went on to college, my mom moved, and one day I visited her chiro...while waiting for my mom I picked up a pamphlet that discussed the studies that have shown that children with disabilities (cerebral palsy, Down syndrome, and others) were helped with chiro. Not cured, but the problems that the children had were made better, when under chiro care. Right then and there I decided to become one.
And I did, and I did quite a bit of good, even on the animals of my practice members (I don't like the word patients). Couldn't charge for the animals, but people brought them to me, and those animals got better under my care, it was incredible. So did the people.
When I was in school, I discovered (when my grandmother told me) that my great grandfather had been a chiro for a few years. His wife had been desperately ill for quite some time, and nothing could be done for her. In desperation he brought her to a DC (illegal in that time in NJ, where they lived), and she quickly healed from her illness. He became a DC, and practiced for a matter of years. Every so often someone would report him and he would be put in jail for awhile...his patients would bring him chocolate bars, and eventually one of them would appeal to the mayor, and they would let him go. He cared for a girl with Down syndrome...in that time those children didn't live very long at all. But this girl lived into her 20s, and her parents definitely felt that the chiro care was the difference. Ultimately NJ made him close, they kept hounding him...some years later it was legalized there, and in fact most of the people at my chiropractic college were from NJ.
I did end up closing my practice, b/c my philosophical point of view combined with my refusal to play games with insurance companies, along with being single with no one to help financially as I got my practice off the ground, resulted in my being broker than broke.
But I still do some work for free for family. When I met my husband he had suffered from migraines since he was a toddler. After a year of regular adjustments by me, he doesn't get them anymore. Sometimes he'll get a very nasty headache (like once in 6 months), but they are not migraines anymore, and he doesn't have to spend the day in a dark room.
Although the first body-work my son had was cranio-sacral therapy, done by a massage therapist, at 2 weeks, soon we took him to see my friend that I went to chiro school with. One day I mentioned that I was getting concerned about DS not 'cross-crawling', meaning that he wasn't crossing the arms and legs, he was doing just one side then the other. I have found through learning about learning modalities that cross crawling is actually quite important. My friend said "hmm", checked out DS's hips, did a tiny little soft adjustment, and the very next day DS was able to cross-crawl. Seemed that there was something holding his hips up that was keeping him from that movement. When I told my friend on our next visit, he said "hmm".

He's really not symptom-based at all.
Anyway, chiro is good stuff. Just like anything, the *person* makes a difference. If you don't like the person or how they work, find someone else. There are many different techniques, and each person has their own philosophy and way of practicing.
Chiropractic, unless done horribly wrong (as with any health care option), won't mess up your spine. What people sometimes "fear" is that "once you go, you have to go back". But that actually means that when people go, they notice changes and differences. Once their bodies start to heal themselves, they LIKE how they feel, and do not want to go back to how they felt before. So they "have to" go back, because they want to feel better, they don't want to be stuck where they were before.