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Overview | Mission | History | Staff | Links | Upcoming Events | Research Activities | Educational Activities Office Location Location: 399 Farmington Avenue Farmington, CT Telephone: 860.284.0201 Fax: 860.284.0213 Contact Person Sylvia Õunpuu, M.Sc. - Director/Kinesiologist E-mail sounpuu@ccmckids.org Clinician Referrals: Procedure What is Motion Analysis? The goal of gait analysis is to measure and evaluate the walking patterns of patients with specific gait-related problems, for example, tripping and falling, joint pain. With these specific concerns in mind, we ask ... is the patient walking differently from how they might walk normally? Are measured differences related to their walking problems? What can be done to help the patient walk better? To examine all aspects of the patient's walking pattern, some rather sophisticated technology is used. Targets with highly reflective surfaces are placed on the patient's skin at specific points on the legs and torso. A specially equipped set of five or six video cameras that are placed around the laboratory space view the patients as they walk down a central pathway. These cameras are connected to computers that perform different types of analyses. From this information, we can carefully examine how the patients' legs and other body segments move in space and how well the joints work as they walk. Other equipment in the lab measure the forces under the feet and muscle activity while walking. This additional information allows the staff to analyze the mechanics of walking in more detail. We can understand how much (or how little) torque and power each of the joints is producing while the patients walk. For example, are the muscles working together to produce the required forces? Is the timing of these muscles appropriate? Do the muscles need to be strengthened through exercise? Or are certain muscles pulling too hard because of spasticity? In this way, the subtleties of the patient's walking problem are better understood and the causes identified. An interdisciplinary team that typically includes physicians, physical therapists, kinesiologists, and engineers, then reviews all of the data and makes a treatment recommendation. Treatment recommendations can include, but are not limited to, physical therapy, medications that affect muscles, bracing, and surgery. Who might benefit from gait analysis? Any child, adolescent or adult who is experiencing significant difficulties in walking. Most commonly, we see patients with neuromuscular disorders such as cerebral palsy, traumatic brain injury, myelomeningocele or stroke in the Center for Motion Analysis. More and more, we are also seeing patients with unexplainable pain in their hips, knees or ankles. If my doctor or physical therapist videos me (or my child) walking, is this "gait analysis"? Yes, the use of a video camera alone is a type of gait analysis that can help the properly trained clinician better understand your walking problems. The information that this approach can produce, while useful, is very limited however. This type of video analysis alone should not be confused with the more complete clinical gait analysis described above. Gait analysis is a broad term that refers to the systematic evaluation of a subject's walking pattern. While normal gait is intricate, pathological gait is more complex as primary pathologies may be difficult to recognize. The most common use of clinical gait analysis is in the treatment decision making process for children with neuromuscular disorders such as cerebral palsy. The complex gait deviations of these children occur in three planes of motion and primary deviations are often confounded with compensations. Consequently, a complete appreciation of the particular subject's ambulatory impairment is difficult, if not impossible, with observational gait analysis alone. The most comprehensive gait analysis today, of the type that is offered at Connecticut Children's Medical Center, provides for the evaluation of video records, clinical measures, stride and temporal gait data, three dimensional joint kinematic (motion) and kinetic (forces) results, electromyographic data, metabolic energy expenditure, and foot pressure. Each mode of evaluation provides important information, yet none is complete in and of itself. Video-taping Video-tape records provide a qualitative documentation of how a person walks affording an opportunity to evaluate the "smoothness" or "fluidity" of a gait pattern. The ability to obtain close-up views of a specific motion and to use slow motion greatly enhances the observer's ability to evaluate the subject's walking pattern. For example, close-up views of the feet provide a means for the evaluation of hind foot position and motion. Clinical Assessment The clinical assessment provides measures of the subject's status at rest. The specific measurements included will depend somewhat on the pathology being evaluated. These may include passive joint range of motion, joint contracture, muscle strength and tone, bony deformity, and neurological assessment. This information may then be correlated with the gait data to help determine the potential causes of the subject's gait deviations. Stride/Temporal Parameter These include such parameters as velocity, cadence, stride length, step length and percentage of stance/swing. These quantities are termed "outcome" measures and provide an indication of the level of function when compared to normal values. They do not, however, give an indication of the cause of the gait abnormality. Joint Kinematics Joint kinematics describe the rotational displacement at each joint during gait. The most common technique of obtaining motion data for clinical use (and the approach used at our laboratory) involves the use of reflective markers, aligned with respect to specific bony landmarks on both lower extremities, pelvis, and trunk. With the use of strobed infrared light and computer-interfaced video cameras, the three-dimensional motion of each marker is determined and joint angles computed. Joint Kinetics Joint kinetics provide information about the forces associated with motion abnormalities. Also referred to as joint moments and joint powers, these parameters are computed using mathematical relationships drawn from physics that combine ground reaction (force) data and estimates of segment weight with the motion information. Muscle Activity Dynamic electromyography techniques (EMG) use either surface or intramuscular electrodes to monitor muscle activity. The EMG signal gives information concerning the "on-off" activity of a muscle. This information can be used with joint kinematic and kinetic results to understand better the subject's neuromuscular abnormalities. Metabolic Energy The assessment of metabolic energy during walking provides a measure of the overall ambulatory status of the patient. This technology allows a direct evaluation of one of the primary determinants of gait, that is, energy conservation. Pedobarograph The pedobarograph measures pressure distribution under the foot while walking. The patient walks barefoot over a very thin "plastic" mat. If the pressure between the foot and shoe needs to be recorded, special insoles are custom cut to fit into the shoe. Usually, a referral for gait analysis is made when all methods of conservative treatment have been tried and surgical options are being considered. This typically occurs after the child has reached a plateau in terms of improvement in ambulation or when orthopaedic concerns necessitate treatment, i.e., hip subluxation or severe joint contractures. Multi-level surgeries are now performed in order to address all areas of dysfunction during one surgery. This not only reduces a child's exposure to anesthesia, but it also reduces the need for frequent hospitalizations. Gait analysis is invaluable in the identification of these multiple areas of impairment that are difficult to correlate by observation and clinical assessment alone. When used as a pre-operative tool, the child with cerebral palsy may often need only one surgical package of treatment during the growing years. Who is appropriate for gait analysis? Computerized gait analysis techniques are appropriate for any adult or child who has a gait problem that requires treatment. Because of the complexity of gait abnormalities in neuromuscular disorders, gait analysis is most commonly performed on this type of patient. Gait analysis is appropriate for decision-making in such disorders as cerebral palsy, stroke, traumatic brain injury and myelomeningocele to name a few. Because of the complexity and expense of the test, gait analysis is primarily used as part of the surgical decision-making process at the point in time when all conservative treatment has been tried and surgical intervention is being considered. Gait analysis is not limited to only this application, however. Questions concerning bracing issues can be addressed using gait analysis techniques, for example, is the brace performance consistent with the prescriptive objectives? Evaluation of the rate of deterioration in progressive disorders that affect gait can also aid in understanding a patient's abilities. Another valuable function of gait analysis is in the assessment of the efficacy of surgical intervention. Routine analyses of postoperative status provides the clinician with more objective information to evaluate the effects of treatment. There are a number of factors to consider when referring a child for gait analysis. The child must be ambulatory, with or without assistive devices, for a minimum of ten consecutive steps. A minimum height may be required (at our laboratory, it is approximately 40 inches tall) in order to achieve required measurement precision goals. The child must be able to follow simple directions and behaviorally tolerate the placement of reflective markers and electromyographic electrodes on the skin. The level of cooperation may influence their testing ability given the length of a typical gait analysis. Although cooperation can be encouraged with the use of toys as distractions, in cases of severe cognitive impairment, cooperation may be an issue of concern. The actual time required for a gait analysis assessment varies depending on the number of tests performed and the level of cooperation of the patient. If a child has orthoses, tests may be needed with and without (barefoot ) the orthoses to address clinical question(s) concerning brace wear. Usually testing can be conducted as the subject uses any necessary walking aids. In our experience, a full gait analysis which includes all the above parameters will take approximately three to three and one half hours. In summary, computerized gait analysis provides the tools necessary to evaluate both normal and pathological gait in a more objective fashion. The art of sophisticated clinical gait analysis lies in the integration of many methods of analysis to arrive at a more complete assessment of a child's gait pattern. Proper gait data interpretation is dependent upon the care with which gait data is collected and the experience and expertise of the clinical team, consisting of physicians, physical therapists, kinesiologists, engineers and technicians. The staff at the Connecticut Children's Medical Center, for example, brings to the process the experience gained from over 5,000 gait assessments in the many years of laboratory operation as well as the knowledge gained from the publication of dozens of papers pertaining to clinical gait analysis.