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