Brief Answer:
Read below.

Detailed Answer:
I read your question carefully and I understand your concern.

Back pain is a very common problem. As the spine undergoes changes due to the wear and tear over the years, it becomes even more common with age, especially when there is the overweight issue which adds to the load on the spine.
At times it may be a simple muscle spasm, but since you describe it to radiate in the lower limb to the heel then that speaks in the favor of a nerve root compression, causing pain from the back where the nerve originates and all along its trajectory in the lower limb. The most common cause is a herniated, displaced intervertebral disc compressing the nerve root.

In terms of treatment, for the moment painkillers like Advil you are taking are the first steps. A muscle relaxer like Flexeril may be added for a few weeks. After the first few days where bed rest may be helpful should return to activity and consider starting physical therapy. While painkillers simply alleviate the pain until the inflammation subsides spontaneously, so do not alter the course, physical therapy is the only means for a long lasting benefit. It includes exercises to strengthen you core muscles enabling them to support the spine and ease the load.

Symptoms may take a while to subside, but they eventually do in 80% of the cases and no other treatment is needed. Only if after 4-6 weeks there is no improvement can other more invasive approaches like local injections, or as a last resort surgery be discussed.

One question my patients often ask is whether they need imaging with CT or MRI. Since as I said most of them improve spontaneously I usually reserve it only in cases which do not improve in 4 weeks. Exceptions to that rule may be if you develop weakness of the limbs, bladder control issues, fever or if there is a history of trauma, cases where more immediate imaging is needed to exclude causes such as tumors, fractures, abscesses etc.

I remain at your disposal for other questions.

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