Leg Length Discrepancy
Why is a 35 year old man consulting a health professional for back pain getting a prescription for a lower limb scanography (X-rays to measure leg length discrepancy) for a potential correction (heel lift)?
Especially knowing that:
1) He has lived with this leg length discrepancy for at least 15 years;
2) Lower limbs X-Rays have a major radiation effect on the gonads. (Which indicates that this paraclinical test has to be less often prescribed in order to avoid potential health problems associated with radiation);
3) The error of measurement of lower limb scanography is considerable (1 cm inter-rater on X-rays image reading in addition to the error of the machine itself) as is the error of measurement of health professionals using a measuring tape (2 cm intra-rater and 2.5 cm inter-rater);
4) The differences in leg length are universal. The body is never perfectly symmetrical;
5) According to two systematic reviews, one written by a physician and the other by a chiropractor, it takes more than a 2 cm difference to have an adverse and significant impact on biomechanics, pain and function;
6) Differences of more than 2 cm are extremely rare or even non-existent in the runner if the individual has not had a major fracture or surgery or a specific disease (such as poliomyelitis);
7) The effect of leg length correction is not well documented and we do not know what are its long-term outcomes.
So please, fellow health professionals, stop prescribing a heel lift to someone who has had a leg length discrepancy for a long time, even if the patient is consulting for low back pain. If you ever use it as a therapeutic tool and that it worked out well, please (again!), have it removed after a few weeks... or months. And what about non-standard anatomical and biomechanical features like the right foot pronation of Haile Gebrselassie, the right knee dynamic valgus vector and right foot external rotation of Geoffrey Mutai, the anterior pelvic tilt of Buzunesh Deba or the flat feet of Mr."X" or the cavus feet of Mrs."Y"? (More information in a 3-day course that will give you straight thinking and clarify these blurred and sometimes doubtful links... for info click here)