The Truth About Leg- Length Discrepancy 

What is a Leg Length Discrepancy (LLD)?

Leg Length Discrepancy (LLD) is when there is an inequality in the length of the legs so that one appears to be shorter than the other. 

When assessing the musculoskeletal system, the most important sign of dysfunction can be a leg length discrepancy (LLD). Many of those in the medical profession, including Orthopedic Physicians, Doctors of Osteopathy, Chiropractors and Physical Therapists often ignore how important a leg length discrepancy can be for a patient with pain or dysfunction.

The following is based on personal clinical experience as a physical therapist for 27 years and a teacher of the MPS therapy since 2000.

The most common factor found in most of the patients who complain of pain in the spine, lower extremities and/or sports injury is a leg length discrepancy (LLD). This is an extremely important finding and is essential in treating for pain because the LLD is the cause of the pain.

In most cases, when the cause of the symptoms is taken away, the pain is eliminated. Many health care professionals including chiropractors, MDs and DOs notice the discrepancy, but they do not recognize the clinical importance of this finding (1). Some researchers do not recognize a LLD less than two centimeters, or 0.78 inches (2). Others determine that LLD can be an indication of injury in athletes (3) (4). The most important research about LLD, they did a mathematical analysis to prove the changes in the distribution of the body weight in a patient with LLD. They found out that a discrepancy of 1cm in a 60 kg person transfers an extra 3.675 kg to the shorter leg (5).

Often the solution for leg length discrepancy for Physical Therapists, Chiropractors, Doctors of Osteopathy and/or Podiatrists is a lift in the shoe. Orthopedic surgeons may attempt to correct a limb length discrepancy with surgery. This may correct alignment temporarily but will not correct the original issue which is the cause for the LLD. 

What's the Truth? 

There are two types of leg length discrepancies: Anatomic and Physiological

Anatomic Leg Length Discrepancies

These cannot be corrected because usually a true anatomical problem is present.


They include:

  • A decreased angle of inclination of the femur

  • Flattening of the femoral head due to illnesses like Pertes disease

  • A femoral or tibia fracture, and other anomalies


In these cases I recommended a lift in the side of the discrepancy to correct it.

Physiological Leg Length Discrepancies

These can be corrected by utilizing 15 minutes of treatment with magnets. I found that more than 90% of my patients and students had the physiological LLD. Before you can correct the LLD, you must be able to find the discrepancy. The easiest way to assess a patient is when they lie supine on a mat or massage table. The patient should wear firm, tight-fitting shoes to better evaluate the leg length discrepancy. If the patient does not have the appropriate shoes, the apex of both medial malleoli can be marked. The legs discrepancy is easily noted when they are lifted a few inches above the table and are held up in the air.


To correct the discrepancy, a magnet with positive polarity is placed on the lower thoracic area around the twelve thoracic vertebras on the side of the shorter leg. If the magnet corrects the LLD, then the patient had a false or physiological leg length discrepancy.


Treating this discrepancy early in life can be the most important factor in avoiding pain and injuries.


1. "Back Pain: The Long and the Short of It." Advance for Physical Therapy & Rehab Medicine. Volume 15, Issue 24

2. "Options Abound to Help People with Discrepancy." Advance for Physical Therapy & Rehab Medicine. January 12, 1998

3. "Pinpointing biomechanical faults can keep athletes on their feet." Advance for Physical Therapy & Rehab Medicine. Volume 11, Issue 5

4. "Avoiding injury in the long run." Advance for Physical Therapy & Rehab Medicine. Volume 13, Issue 25

5. Edgardo Hidalgo Callejas: "Desequilibrio del peso corporal, cálculo matemático y consecuencias clínicas", Revista CUESTIONES DE FISIOTERAPIA, de la Universidad de Sevilla, número 22 del año 2003

Personal Observations

Several years ago, while working in a pediatric hospital, I had several patients, all male teenagers, who had lumbar laminectomies to correct injuries sustained from playing football or soccer. They also all had a leg length discrepancy. This got me thinking. Could this LLD be a factor in their injury?


Over the next few years I evaluated every patient I treated for leg length discrepancy. In 2007, when I was working as a physical therapist in an outpatient clinic for a year, I found that 80% of my patients with musculoskeletal pain had a leg length discrepancy. In the pediatric hospital, when training patients with crutches prior to a foot surgery for non- traumatic foot pain, I discovered all the patients had a leg length discrepancy. For me it was clear that this difference in leg length weakens and produces unbalance of the loads of the musculoskeletal system so an injury was more likely to occur.

Many of my adult patients with back or extremity pain have a history of playing competitive sports. More than 50% of these patients quit their sport because of repetitive injuries. Those patients also state that after they stopped playing the sport, the pain disappeared for years, but returned when they reached their thirties or forties.


All of those patients had a leg length discrepancy.

Another interesting find was that headaches were directly correlated to patients with a leg length discrepancy. Patients with a history of headaches since childhood had a leg length discrepancy.

As a father with 3 children who play sports, I've gathered histories and facts regarding sports injuries. When I was traveling to different cities with my son who played competitive soccer, I was often asked to help when a child was injured. The most interesting finding was that every child that complained of repetitive injuries, such as pain in the spine, knees or feet, without a trauma showed a leg length discrepancy.


My daughter's gymnastic coach told me that some of the girls doing levels 4, 5, or 6, would sometimes lean slightly after they tumbled and landed on their feet. He also stated that when those girls flipped backwards, starting in the position where the coach's hands hold the feet of the girls, he had felt them push asymmetrically. Of course, 100% of those girls had a leg length discrepancy.

Though all of these patients had a variety of problems and symptoms, the root of the problem was always a discrepancy in leg length. As physical therapists, we treat the consequences of the problem, i.e. muscle pain and tenderness, weakness in some musculature and/or contractures in other. We do muscle energy techniques, mobilization of the joints, and exercises to strengthen and improve posture. We apply many physical therapy agents from TENS units, short wave, ultrasound and electrical stimulation. DC's and DO's believe that everything comes from misalignment of the spine and the main treatment is manipulation of the spinal joints. MD surgeons perform surgery to fix all kinds of problems from lumbar laminectomy for a disrupted disc to navicular transposition for foot pain.


None of the above treatments address the root cause of the problem: the leg length discrepancy.