First off, to the below comment; Vicoden is a narcotic; it is used a pain reliever. It does nothing to reset a nerve/muscle.
You more than likely pulled/twisted the muscles in your back. You might have even have bulged (herniated) a disk.
Take Motrin/Advil, those are anti-inflammatory medications and will help a lot! Ice it for the first 48 hours 20 min on, 20 min off. Then heat after that. The exercises they are giving you are to #1 to loosen the muscles and/or #2 strengthens your core muscles.
A chiropractor would probably do you a lot of good!! A good adjustment will align the spine and relieve muscle strain. If you have a bulged disk, most of the time it will even take the pressure off the nerve...
If you do have a pinched nerve you might have pain in either or both of your hips, shooting down the legs. I might ask the doctor for a muscle relaxer. Most common ones are Soma, Flexeril, or Skelaxin. (They can make you sleepy, if you have never used a muscle relaxer before I would recommend the Skelaxin; typically it does not make people sleepy)
I have suffered with chronic back pain for many years, (I have many different issues with my lumbar spine.) so I am very familiar with the treatments for back pain. With what you are experiencing I would assume the pain would be gone within 2 weeks or so.
When you get to the stage of chronic pain, you will be sent to see a neurologist. They will usually, send you for MRI's, CT Scans, x-rays, sometimes an ultrasound of the spine, then do a nerve test to see how badly affected the nerves are. They will usually start with Physical Therapy and medication. There are medications to treat nerve pain such as, Lyrica, Cymbalta, and Neurontin and so on. If that does not work then you will see a pain specialist who typically starts off with cortisone injections, then moves down the list... interlaminar epidurals, Translaminar Epidural, and so on. (All of which I have had and none of which have relieved my pain,)
The last resort is surgery. I am trying to avoid the surgery my doctors recommend. All surgeries can have serious complications. I have had several surgeries throughout my life. 4 on my knees alone. I never really considered the complications that could occur. Last year after my hysterectomy I had very severe complications. 4 days after coming home from the hospital I suffered Massive Bi-Lateral Pulmonary Embolisms. (Lots of blood clots in my lungs, they stopped counting at 8) By every medical standard I should have died that night; April 20th 2009. I was 28 years old! I am a mother to 4 beautiful children, ages 8, two 6 year olds and a 2 year old. So as you can imagine I am very afraid to ever have surgery again.
I currently take a variety of medications to get me through the day. 40 mg flexeril a day (20 morning and 20 night) two 5/500mg vicoden 3x's a day or two 5/325 percocet for pain depending on my pain level during the day. The first number refers to the amount of narcotic; the second number refers to the amount of Tylenol. So if you ever are prescribed one of these pain medications do not take any additional Tylenol products. Then I take 7mg of Valium nightly. Valium can be used for many different reasons, in my case it is used as an additional pain reliever and muscle relaxer, for me it has a sedating affect to help me sleep, pain free. On the nights that I am in too much pain to move/walk or function normally I also have Oxycodone to add to the mix. This is an opioid analgesic medication that is time released; it is also used for pain relief. This is my last resort of the really bad days. For an anti-inflammatory I take 800mg Motrin 2x's a day. Sometimes doctors will prescribe naproxen, it is also an anti-inflammatory, but does have the affect of pain relief.
Here is a website to help you understand more about back pain and the causes:
I hope your recovery is quick and the information I have provided helps you to understand the process of what can happen with chronic back pain.