THIS week I am very pleased to answer three readers’ questions regarding muscle and joint issues. My advice is given in good faith, according to current guidelines, but is not a substitute for consulting your own doctor.

Question – I’ve had low back problems for years. The pain has got worse and now shoots down my left leg all the way to my foot. Why am I only getting a scan of my lower back, and not my entire leg? - Paul, 67

Answer – From your description you have a disc in your lumbar (lower) spine, pressing on a nerve root. The nerves come off the spinal cord and pass through an opening between two consecutive vertebrae.

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Magnetic Resonance Imaging (MRI) is the most commonly used tool to look at the state of the spinal canal, and if a nerve root is being compromised.

When the nerve runs in your leg, it is less likely to be compressed by anything surrounding it. Hence scanning the leg will not add any useful information.

The degree of compression of the nerve, as well as the severity of your symptoms, will guide those treating you as to what to do next.

Question – I thought I had hip pain, but even though my x-rays show arthritis, the physiotherapist advised it was coming from my lower back. Please can you explain – Sandra, 60

Daily Echo:

Answer – Hip and low back pain are often confused. If your pain is in the lower back, it is less likely to be coming from your hips. If you feel pain on the outside of your leg at the top, this is most likely to be trochanteric bursitis. This is an area on the top of your femur, similar to the knee cap. Like the knee cap, it can become inflamed and pain may go down the outside of the leg.

The hip joint itself is a ball and socket joint and sits deep in the groin. The pain from hip arthritis is felt in the groins, or in the middle of the buttocks.

While x-rays may show arthritis, if the pain is not coming from this region, it is likely that this is not the cause of your symptoms. The majority of people over the age of 40 will have some degree of arthritis on x-rays, whether they have symptoms or not.

Question – I have pain in my shoulder but because I’ve been a smoker, the GP requested a chest x-ray as well as my shoulder, and marked it as urgent. I’m extremely worried – Martin, 65.

Answer – shoulder pain may be caused by problems other than shoulder arthritis. If you are a smoker, or have recently stopped, your doctor may be concerned about the possibility of a lung cancer in the top of your lung on the side where you are reporting shoulder pain.

Hopefully your chest x-ray will come back as not showing anything suspicious. This may give you the motivation to think about stopping smoking.