This question requires a little deeper answer than 'yes' or 'no'; and furthermore what a health care provider might mean when they say you have a short leg and the implications for that will differ from provider to provider.
So I'll answer this question exactly as I do in my office with patients with the same level of detail. I'll also explain misconceptions and how leg length should be measured in order to be as accurate as necessary.
Question: Do you have a short leg?!?
Answer: Most likely.... YES! However, for most people it often DOES NOT MATTER and does not mean you need any sort of heel lift!
Why not?
Numerous studies dating back decades demonstrate that a majority of people have a leg length (from the hip to the ankle) difference of 1-5mm... upwards of 90% of people. Very few people have perfectly, even leg lengths. A difference this small is something that most people's bodies and musculature have the ability to overcome (provided their posture and muscle tone is balanced by having a balance head and neck... NUCCA!). This difference is not usually associated with any sort of back, hip, knee, or ankle pain. In short, it has no negative implications on your well-being.
The other 5-10% of people may have a leg length difference of more than 5mm and it may be large enough that their body cannot compensate properly and it can result in bio-mechanical pain in their back, hips, knees, etc. However, not everyone with a leg length difference of more than 5mm can't compensate enough- many with large differences in leg lengths function perfectly fine with no issues.
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The problem with considering leg length is that many providers believe that any leg length difference will always result in dysfunction (it doesn't). The reality is that asymmetry (both sides of the body not being identical) is actually the norm and is not inherently a problem.
Most people who have a difference in legs of 1-5mm (and often even more) simply need their neck balanced (i.e. with NUCCA) so that muscle tone is balanced in the whole spine and their low back and body will compensate in a balanced and healthy way.
Another problem with measuring true leg length is that it is often done only considering 1 or 2 variables and not the whole picture.
For example, if you lie on your back and have someone look at the bottom of your feet, a majority of people will demonstrate one leg that appears shorter. If this is the ONLY measurement that is used to determine you have a short leg, the assessment is not nearly thorough enough and is not complete. This would be looking at a car without starting it and determining that it is either garbage or worth $25,000- you have no idea until you start it up, examine from numerous angles, and ensure it functions well.
When you lie on your back, there is often a muscle imbalance and one hip may be drawn upwards because it is tighter giving the appearance of a short leg when in fact they may be even... or the other one may be longer.
Going further, some will only consider the height of the pelvis when standing and use palpation (touch) to determine which side of the pelvis is higher. However, once again this is an imperfect method because muscle tone can affect what the provider feels as well as a pelvic twist that can cause the height to be altered from the true length.
There are numerous times that myself, the patient, and even other providers feel is the high hip only to be refuted by X-rays of the pelvis; sometimes it feels to everyone like the right side is higher only to see on an X-ray the left side is actually higher by 5-10mm.
My point here is that we CANNOT trust what we see in the lying down position because of muscle tone and we CANNOT trust what we feel in the standing position because it is not completely accurate.
So what do we trust?
Only what we can see with X-ray imaging combined with measurements and visualization of the legs on the outside. This is why to determines if one's leg truly is short, we have to look at leg length lying down, we should use a measuring tape to measure legs top to bottom using identical landmarks, we have to palpate the top of the pelvis standing up, we have to take an X-ray image of the low back and pelvis, and we have to correlate that to a patient's symptoms and experience. All of the pieces of the puzzle have to match up before I would ever tell a patient to try a heel lift.
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Lastly, just to make things more confusing, even if we determine that a patient has one leg shorter than the other by 25mm, we have to consider age and whether the low back is already compensating properly or not before prescribing a heel lift.
Is the right pelvis uneven? Is the low back leaning to the right? is it straight? Is it leaning left? Is the person still of the age where their spine can compensate? Is it already compensating properly?
All of these have to be answered before using a heel lift
I have had patients whom were told one leg was 1/2" short than the other simply by looking at their legs when lying down and they were given a 1/2" lift all at one time.
This would be like trying to 2 years worth of teeth/jaw movement with braces in 24 hours. It's not safe or healthy.
Once we know someone needs a heel lift, it has to be implemented in small increments over the course of weeks and months to allow the spine and all other structures to move and compensate in a healthy way.
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So, in short... Are your legs really different lengths? Probably. Does it matter? Probably not. If it does matter then it needs to be measured properly. When it is measured properly, it needs to be dealt with precisely and incrementally.
The reality is that we cannot be absolutely sure that legs are uneven or that the body can't compensate well enough before muscle tone, posture, and the neck alignment are corrected. This is why NUCCA is absolutely vital before prescribing heel lifts or dealing with potentially uneven leg lengths.
If you have questions about leg length, pelvic that is not leveled, heel lifts, postural distortion, or if your hip and/or low back pain is stemming from an imbalance relating to a neck misalignment, do not hesitate to contact our office (or your nearest Upper Cervical Chiropractic office) to ask for a complimentary consultation or assessment.
Dr Justin