A new treatment for back pain in Belfast 2017

Leg length inequality and a pelivis that is not level is a common cause of low back pain.

The biomechanics of the lower back is closely linked to the biomechanics of the foot, leg, and pelvis.

Doctors may be tempted to only focus on the back with their back pain patients, however oftentimes the stresses in these tissues are caused by biomechanical problems in the feet, knees or pelvis. Failure to address biomechanical problems in these areas often results in poor clinical outcomes  and the patient fearing the problem will never get better.

Successful management of low back issues requires full assessment of biomechanical problems of the lower extremities and pelvis because they are linked through the kinetic chain effecting posture and ambulation.

The first large research study into leg length issues was carried out over 70 years ago

In 1946, Lieutenant Colonel Weaver A. Rush and Captain Howard A. Steiner of the X-ray Department of the Regional Station Hospital of Fort Leonard Wood, Missouri, took standing lumbosacral X-rays on 1,000 soldiers for the specific purpose of measuring differences in their leg lengths and to determine if inequality of leg length was a factor in the incidence of back pain. Their research was published in the American Journal of Roentgenology and Radium Therapy and is titled 1): A Study of Lower Extremity Length Inequality.

23% of the soldiers had legs of equal length.
77% of the soldiers had unequal length of their legs.

No difference was noticed in limb shortness between the left and right legs and the average shortening was slightly more than 7 mm.

Importantly, the authors noted that the short leg was associated with a tilt of the pelvis and a scoliosis.

The Authors noted: “It was a general consistent observation that the degree of scoliosis was proportionate to the degree of pelvic tilt. An individual who has a shortened leg will have to compensate completely if he intends to hold the upper portion of his body erect or in the midsagittal plane.”

They also noted:

"Leg length differences exceeding 5 mm were associated with the greatest low back pain or disability, and therefore 5 mm is labeled as being a “marked difference.”

“For this reason, it is our opinion that the existence of such a condition [a short leg exceeding 5 mm] is significant from the standpoint of symptomatology and disability.”

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Travell & Simons’ Myofascial Pain and Dysfunction: The Trigger Point Manual:

In these books, Drs. Travell and Simons discuss difficult cases caused by structural deficiencies, the most common of which were:

A difference in the length of the lower limbs.
A long second metatarsal or a short first metatarsal.

It has been documented since 1946 that around three quarters of the population have unequal leg lengths and that about a third of people have leg length differences that can perpetuate trigger points (2). As a general rule, the sacrum is lower on the side of the short leg. The spine initially tilts towards the short leg, then compensates back to the midline as a consequence of chronic contraction of the quadratus lumborum muscle. Dr. Travell states the resulting trigger points in the quadratus lumborum muscle are a very common but frequently overlooked cause of chronic low back pain (3).

Dr. Travell stated that the solution was a heel lift for the short leg, these are commonly applied using orthotics in modern clinics

This concept of a pronated foot lowering the pelvis on the same side, altering lumbar spine biomechanics has been confirmed in more recent publications, including sports medicine reference books authored by podiatrists (4).

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Another cause for the increased occurence of low back pain in individuals with an anatomical short leg is that it can also cause counter-rotational stress at the L5-S1 intervertebral disc. This phenomenon was best described by Ora Friberg, MD, from Finland. Dr. Friberg published his findings in 1987 in the journal Clinical Biomechanics, titled (5): The Statics of Postural Pelvic Tilt Scoliosis;A Radiographic Study on 288 Consecutive Chronic LBP Patients

BACKGROUND ANATOMY

The intervertebral disc has two components. The center of the disc is called the Nucleus Pulposus, or simply nucleus. The nucleus is mostly water and functions as a ball bearing, allowing the vertebrae to bend and twist.

In this study by Friberg, standing X-rays of the pelvis and lumbar spine in 288 consecutive patients with chronic low back pain and in 366 asymptomatic controls were taken. The findings showed that 73% of the patients assessed had more than 5mm difference in leg length. The incidence of leg length inequality in lower back pain patients was twice as much as the patients with no pain (controls).

Friberg emphasized the counter-rotational stresses on the L5-S1 disc: "These “significant” counter-rotational stresses primarily affect the L5-S1 intervertebral disc. The consequences of these counter-rotational stresses at L5 are accelerated disc degeneration and degradation, back pain and sciatica."

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A recent (2016) study pertaining to the biomechanical consequences of an anatomical short leg was published in the Journal of Craniovertebral Junction Spine and titled (6): Inequality in Leg Length is Important for the understanding of the pathophysiology of Lumbar Disc Herniation.

The researchers studied 39 subjects with leg length inequality and low back pain and 43 controls to note the differences in occurrence of disc herniation between between the two groups. They found that leg length inequality causes spinal joint load assymetry, accelerating disc degeneration and disc herniation. They also suggested that poor low back disc surgical outcomes may be linked to the abnormal spinal loads caused by leg length inequality, They state:

“Inequality in leg length may lead to abnormal transmission of load across the endplates leading degeneration of the lumbar spine and the disc space.”

“Patients with chronic lower back pain have minor balance defects. Inequality in leg length is important for understanding of reasons behind lumbar disc degeneration and herniation.”

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This year (2017), a very important article was published in the Archives of Physical Medicine and Rehabilitation, titled (7): Shoe Orthotics for the Treatment of Chronic Low Back Pain: A Randomized Controlled Trial.

The aim of this study was to investigate how shoe orthotics with or without Chiropractic treatment for chronic low back pain compared to no treatment at all. This was a randomized controlled trial (three groups) that involved 225 adults with symptomatic low back pain of 3 months or longer:

Group 1:"Orthotics Group" received custom-made shoe orthotics only.

Group 2: "Plus Group" received custom-made orthotics plus Chiropractic treatment.

Group 3: "Wait Group" received no care.

Both pain levels and disability were assessed at 6 weeks and 12 weeks, and then after an additional 3, 6, and 12 months. These authors note:

“The best results were in the Orthotics Plus Chiropractic group in which 70% had a decrease in pain and 56% a decrease in disability of 30% or more compared to baseline.”

“This large-scale clinical trial show that LBP and disability were significantly improved after six weeks of orthotics care compared to a wait-list control, and that the addition of chiropractic care with the orthotics demonstrated a significant improvement in the disability scores compared to orthotics alone.”

“Foot  and leg length dysfunction must not be overlooked as a contributing factor in treating lower back pain.”

References

Rush WA, Steiner HA; A Study of Lower Extremity Length Inequality; American Journal of Roentgenology and Radium Therapy; Vol. 51; No. 5; November 1946; pp. 616-623.

Travell J, Simons D; Myofascial pain and dysfunction, the trigger point manual: THE LOWER EXTREMITIES; New York: Williams & Wilkins, 1992.

Simons D, Travell J; Travell & Simons’, Myofascial pain and dysfunction, the trigger point manual: Volume 1, Upper Half of Body; Baltimore: Williams & Wilkins, 1999.

Subotnick SI; Sports Medicine of the Lower Extremity; Churchill Livingstone; 1989.

Friberg O; The statics of postural pelvic tilt scoliosis; a radiographic study on 288 consecutive chronic LBP patients; Clinical Biomechanics; Vol. 2; No. 4; November 1987; pp. 211-219.

Balik SM, Kanat A, Erkut A, Ozdemir B, Batcik OE; Inequality in Leg Length is Important for the Understanding of the Pathophysiology of Lumbar Disc Herniation; Journal of Craniovertebral Junction Spine April-June 2016; Vol. 7; No. 2; pp. 87-90.

Cambron JA, Dexheimer JM, Duarte M, Freels S; Shoe Orthotics for the Treatment of Chronic Low Back Pain: A Randomized Controlled Trial; Archives of Physical Medicine and Rehabilitation; April 29, 2017. [Epub]