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Although there are protocols for orthotic treatment based on standard diagnoses, no two cases are the same—every patient presents with a unique set of circumstances. Slight differences in physiology, lifestyle, or even patient temperament can make all the difference when it comes to the effectiveness of the device that you fabricate and dispense. As clinicians, our goal is to help patients regain as much function and quality of life as possible. Therefore, a clear and precise examination is essential to understanding the root causes of their condition.
Static Evaluation
In order to be consistent, it is helpful to have a systematic approach to the biomechanical evaluation. The static evaluation can be completed in any clinical setting. Ideally, the patient will be wearing shorts and a T-shirt, and you will use a goniometer to measure range of motion (ROM).
There are a number of excellent textbooks and articles that describe the procedures and exact positions from which to take standard measurements. Physical Examination of the Spine and Extremities, by Stanley Hoppenfeld, details a complete evaluation of the hip and pelvis, knee, and foot and ankle. "The Adult Biomechanical Examination" (Podiatry Management, September 1999) is an excellent article, and the website www.learnpedorthics.com provides assessment forms and methodology.
In addition to ROM, you need to check for muscle strength and joint quality of motion, making sure to note pain, crepitus, and resistance. Simultaneous pair testing will allow you to note any differences between the right and left sides. Do not overlook any part of the biomechanical chain, as a limitation in one aspect can affect function in another. Guidelines for normal ROM for each of the major joints are given in the table below.
The first ray ROM is essential to determining the function of the foot. Without normal plantarflexion of the first ray, normal propulsion is not possible. First ray ROM is typically 1cm: 5mm of dorsiflexion and 5mm of plantarflexion. Likewise, first metatarsophalangeal joint (MPJ) ROM is also important to foot function. Without sufficient dorsiflexion at the first MPJ, there will be restrictions on the first ray ROM. It can be insightful to take these measurements while the patient is both non-weight bearing and weight bearing to see if a loaded pronatory component restricts the apparent ROM.
Static evaluation should include resting calcaneal stance position (RCSP) and neutral calcaneal stance position (NCSP). RCSP is a visual check of the calcaneal bisection to the ground when the patient is standing and relaxed and there are no compensations present. Look specifically for any heel valgus or varus. NCSP is a comparison when the subtalar joint (STJ) is placed or held in the neutral position; this indicates a rearfoot deformity. The normal value is 0 degrees.
Dynamic Evaluation
The simplest assessment of dynamic gait is the "hallway test." Take the patient into a hallway and ask him or her to walk back and forth a few times. Although this is not a sophisticated test, you can learn quite a bit from it, so it is important not to overlook it as a potential source of information.
Begin by asking the patient to walk shod. Observe the patient and look for any obvious asymmetries, leans, or compensations. Check the position and motion of the patient's head and see if the shoulders and pelvis are level. Look for rotation in the shoulders and hips and for the swing of the arms and legs. In addition, look at the phases of gait and the splay of the feet. Estimating the base of gait (the width of stance) in motion will help determine the effectiveness of your orthotic and shoe modifications. A wider base of gait increases the moment acting down through the center of gravity (COG), which could potentially reduce the effectiveness of the device.
If the patient's feet are not too sensitive and they do not have neuropathy, you can then ask him or her to walk barefoot to see if there is any obvious change in gait. Ask the patient to roll his or her pant legs up so you get the opportunity to observe his or her heel and foot positions in relation to the lower leg during dynamic full-weight-bearing gait. This is also a good time to check for tibial varum to see if it contributes to pronation. One word of caution, however: Watch out for patients who, unaccustomed to walking barefoot with their pant legs rolled up, change their gait to stoop or look down at the floor as they tread lightly on cold tiles!
Observing the patient in motion helps you to understand the fuller picture of how the orthotics will be used. See if the patient walks confidently, requires an aid, or shuffles.
Pressure Mapping
Pressure mapping can help explain some of the findings observed during gait analysis. The ink-mat pedigraph is a simple, inexpensive, and effective way to determine if there are any high-pressure areas. The test can be performed statically with the patient standing, or it can be performed dynamically with the patient stepping through the mat. There are also several digital pressure-mapping systems that work both outside and inside the shoe. These deliver high-resolution color analyses and allow you to see the center of force travel through the foot. Recording pressure during the stance phase of gait indicates where most of the pathology occurs and shows where orthotics may have the greatest impact.
Areas of high pressure, such as the heel, a bony prominence, or a dropped metatarsal head, will reveal themselves quite clearly and may explain gait compensations. Usually, you will cushion or depress these areas to reduce pressure and redistribute the weight. This is especially important in "at-risk" patient groups, such as those with diabetes, Charcot breakdown, or any form of neuropathy.
Asymmetry in pressure between the two feet may reveal a possible leg-length discrepancy (LLD). (Author's note: For a discussion on LLDs refer to the article "Leg-Length Discrepancies: Diagnosis and Treatment," The O&P EDGE, August 2005.) Providing proper treatment and care for the feet, alleviating high-pressure areas, and addressing LLDs will often help to relieve pain that has manifested at the knees, hips, or lower back.
Video Gait Analysis
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| Video gait analysis setup. Photographs courtesy of Super Runners Shop, New York, New York. |
I recently followed a Pedorthic Newswire discussion involving Rick E. Sevier, CPed, CPOA, about dynamic gait analysis. It is simple to set up an inexpensive gait-analysis lab. All that you need are a second-hand treadmill and a video camera (e.g. a Logitech webcam) with a tripod. Draw a light-colored line down the center of the treadmill's running surface and then set the camera up so it can shoot video from behind and from the side of the treadmill. The images can be recorded and saved on a regular laptop and then replayed and watched in slow motion.
Although this is a crude setup, you will be surprised at the depth of information it reveals. Playback in slow motion will clearly show details about the extent of eversion/inversion and foot position at heel strike and toe-off. It can help in the assessment and design of orthotics and shoes. Viewing the dynamic video in a before-and-after fashion is also a valuable patient-education tool. If seeing is believing, this tool will help patients understand what you are trying to do for them.
Shoe Evaluation
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| Video gait analysis in use. |
Pedorthists routinely refer to worn shoes as an "x-ray of gait." You can learn a significant amount just by examining the wear patterns and condition of a patient's current shoes. Riding the New York City subway offers me a wealth of opportunities to examine peoples' worn footwear.
First, look at the style of shoe that the individual is wearing. Is it appropriate for his or her occupation and pastimes? A patient's shoe choices will yield two valuable pieces of information: a possible indication of the trouble source, and just how seriously the patient takes his or her foot problems. If the patient has ill-fitting shoes—too big or too small—he or she may be buying footwear based on something other than fit, such as sale price, fashion, inventory availability, or the mistaken belief that the patient "knows" his or her shoe size.
Even before the advent of digital pressure systems and video gait analysis, practitioners knew that the normal foot-strike pattern was from the lateral heel through the midfoot and finally toe-off from the medial forefoot. This was obvious from the wear pattern visible on the sole of almost every shoe. Check your patients' shoes to verify this. In addition, compare left and right to see if there are any differences. Overwear on a single side indicates a possible LLD, excessive unilateral motion, or some other compensation. Localized compression of the midsole material highlights where weight is loaded during ambulation.
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| Video captured with this basic gait analysis system can be quickly downloaded and viewed on a computer. |
Inspection of the upper will indicate the position and motion of the foot while walking. If the upper is stretched out over the midsole, the shoe could be too tight or there may be excessive pronation or supination. Forefoot deformities will usually announce themselves on the upper. Bunions will cause a bulge at the medial first MPJ. Pronation often manifests as a broken down medial-heel counter, and severe supination breaks down the lateral counter. Functional hammertoes, which are not always noted during a static analysis of the foot, sometimes leave a shiny bump on the top of the shoe. (I know about this because my nice pair of soft loafers tells me so.)
There should be a transverse crease across the upper of the shoe, at the ball, showing the break. If the crease is at an oblique angle (distal to proximal, second to fifth), this is a clue that there may be a restriction of the first MPJ—some form of hallux limitus. An improper crease position may also alert you to incorrect shoe size or poor fit.
The insole also provides a wealth of data for the watchful eye. Look inside the shoe to see if the lining is worn through at any point. It usually indicates localized motion and possibly a poor fit. Areas of pressure on the metatarsal heads or toes will appear as depressions or dark spots on the insole. This tells you where to place metatarsal pads and drops when ordering custom orthotics. If you are brave enough, put your hand inside the shoe and check the integrity of the lining on the roof of the toe box. A worn lining here indicates hammertoes, motion while walking, or poorly cut toenails!
All of these steps are helpful in evaluating patients. This list is by no means exhaustive, but it is a starting point for finding the possible source of biomechanical problems. Without a doubt, when evaluating any patient, your very best tools are your eyes and a keen sense of curiosity—which will ensure you keep an open mind.
Guidelines for Range of Motion
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| Note: Guidelines vary across texts and are based on the technique employed. Source: Physical Examination of the Spine and Extremities, Stanley Hoppenfeld, East Norwalk, CT: Appleton-Century-Crofts, 1976. |
Séamus Kennedy, BEng (Mech), CPed, is president and co-owner of Hersco Ortho Labs, New York, New York. He can be reached at or by visiting www.hersco.com
