- Have You Been Told That One Leg is Longer
Than The Other?
by Dr. Robert
I remember back in physical therapy
school the importance of evaluating and treating people with
various problems that were often directly related to poor posture.
We remember as children hearing from our mothers and grandmothers
to sit up straight, or dont slouch.
Little did they know that we physically could not do what they
wanted us to do. For whatever reason, whether it was tight muscles,
weak muscles, crooked spines, long or short legs, we just couldnt
do what they wanted us to do. Then over time, these minor malformations
continued to persist and even in some cases worsened as we grew
The purpose of this article is to
provide you with some basic information regarding your body.
Most of you have had minor aches and pains, while others may
have experienced, unfortunately, more severe injuries. Its
easy to understand when we have a fall or trip and land funny
on our knee, or twist our ankle from uneven pavement, but it
sure is quite confusing when we awake one day with that little
annoying hip pain. The truth of the matter is that the surprising
hip pain has been developing for quite some time. It just decided
to show its ugly head at this point in time. But why am I having
this pain now? I've never had this pain before. Why all of a
sudden does my hip hurt? I haven't done anything out of the ordinary.
The importance lies within the bodys own adaptive potential.
The basic premise here is that
the body functions as a single unit with many components. Each
component influences and is influenced by other components. Efficient
and normal motion occurs from the complex integration of all
components. Human movement is achieved through the relationships
of the kinetic chain. The kinetic chain includes all bones, muscles
and joints of the human body, but more specifically the lower
half; the feet, ankles, legs, knees, hips, pelvis, and low back.
This linkage system is made up of many component parts, each
with their own set of specifications. These specifications are
similar to what you might find for certain machine parts. In
a way, the human body can be thought of as a machine. However,
unlike a machine that is comprised of right angles and nuts &
bolts, the human body has the capacity to compensate for a malfunctioning
part, and in most cases, in more than one area. The human body
seeks symmetry. It will do whatever it takes to achieve that
and in doing so will compromise tissue health. In turn, it will
wreak havoc on the proper biomechanics of human movement, which
will greatly affect performance. The human body is the great
compensator. It will seek and follow the path of least
The goal of any movement should
seek the minimum amount of energy expenditure and maximum joint
stability. In human walking, the wide variety of structure and
control requires complex integrations for an efficient motor
program. The most observable sign of this is a smooth progression
of the bodys center of mass during ambulation.
Healthy tissue needs force in
order to remain healthy. It requires an optimal amount of stress.
Too much or too little can be destructive! Remember we talked
about how a tissues specifications are similar to those
of a machine? Well, when a tissues tolerance to absorb
force is exceeded, tissue breakdown occurs and inflammation and
pain follow. When inflammation and pain are present, ones
performance will surely suffer the consequences.
One significant condition that
impacts healthy tissue is a leg length discrepancy. Oh, but thats
normal isnt it? Everybody has one leg longer than the other.
Dont they? Sure, not everybody has exact proportional measurements
when they compare the right and left sides of their body. First
of all, how much is significant? This question has been the source
of much debate in recent decades. There have been numerous studies
in the medical literature that examined the effects of leg length
on various structures, most notably in regards to the lower extremities
and the low back. Leg length discrepancies break all of the rules
required for healthy joints in the lower extremities and the
spine. In response to the asymmetry, muscles will structurally
shorten or lengthen to adapt to their new position. (See Figure)
There are two types of leg length
discrepancies that are present. A structural leg length discrepancy
is the anatomical case in which one bone may be longer or shorter
than the other. A functional leg length discrepancy refers to
the result of something occurring in your body such as a soft
tissue contracture or abnormal joint mobility. The most notable
functional leg length discrepancy involves the feet. When we
say a foot is pronated we mean that it is flat (little to no
arch integrity), whereas a supinated foot refers to a foot that
has an arch. Generally speaking, a pronated foot creates a short
leg, and supinated foot creates a long leg. Of course, during
the normal gait cycle, there are appropriate amounts of supination
and pronation that must occur in order to achieve efficient and
The most important role is being
able to differentiate between the two. Unfortunately, differentiating
the two can be quite difficult. In most cases, both situations
occur simultaneously, with one masking the actual degree of the
other. Differentiating between the two scenarios requires an
extensive evaluation that involves gathering information from
several manual tests coupled with information gained from weight-bearing
x-ray measurements. Once the proper diagnosis has been made,
there are various treatment options that are available.
When a structural leg length
discrepancy is present by itself, the most logical option to
equalize the leg length is simply by placing an appropriate lift
under the heel or under the entire foot itself, depending on
the amount of the discrepancy. Most research reports more than
a 1/4 inch difference is pathological. Some studies suggest that
even an 1/8 inch difference can be detrimental especially for
the running athlete. Running causes the ground reaction forces
to increase up to fourfold, as well as, increasing the metabolic
demand. The range of motion of all joints increases with greater
muscle activity required to control these motions.
Treatment for the functional
leg length discrepancy requires the skill of a medical professional
to address any soft tissue limitations. These are most notably
present in which the pelvis may be tilted or twisted in an unusual
position. This situation requires manual therapy techniques to
align joints properly and to reduce any unwanted muscle activity.
In addition to aggressive manual techniques, the use of custom
foot orthotics may be recommended in either a structural or a
functional leg length situation. Asymmetrical foot function may
be causing the leg length discrepancy, therefore appropriate
application of an orthotic device will either correct or accommodate
to the asymmetry.
It should be quite clear that
any treatment option chosen must be made only after a thorough
examination has been completed. The examination should include
an analysis of gait, an assessment of muscle length and strength,
joint mobility, and careful evaluation of foot function.