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