Q. I sustained a T12 incomplete spinal cord injury in 2003. I was trained on how to use intermittent catheters in the hospital. I also wear a condom catheter and a leg bag.

After being home for a while I found that I could empty my bladder into my leg bag by placing a fist low on my abdomen and leaning on it while standing on my leg braces. I tried to cath myself after urinating using the method I just described, and nothing came out — it seemed like I had fully emptied my bladder.

I wonder why I was never informed of this method of bladder management while in the hospital? Do other people use this method? Is this an approved method of emptying the bladder — and can I continue to use it without harming myself? It sure is a whole lot easier than using an intermittent catheter.

— Robert

A. Robert, you bring up a good and often misunderstood question. I have a friend — also a T12 incomplete para — who, when he needs to urinate, grabs onto something, stands and gives a slight push with his stomach muscles. This fills his leg bag, and he is done.

Voiding the way you describe can be done with two similar “external” techniques. The first is called Credé’s method — manually applying pressure to your lower abdomen just below the belly button using a hand or closed fist to push the urine out of the urethra.

The second, the Valsalva technique, is where you flex your abdominal muscles — if you have them — or lean forward to apply pressure to the bladder and cause it to empty.

According to Paula Wagner, a urology nurse practitioner from U.C. Davis Medical Center in Sacramento, Calif., these methods can work in the right circumstances, but should only be used after consulting with a urologist and getting a complete urological workup to see if one or both are the right form of bladder management for you.

The main risk, Wagner explains, is if the urethral sphincter muscle is tight — often the case with people with spinal cord injuries — you will end up with high bladder pressure. High bladder pressure is dangerous and can cause reflux — urine backing up in into the kidneys — which can cause serious and irreversible damage. It can al