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Observational Gait Analysis versus Instrumented Gait Analysis
I was browsing the Web the other day and stumbled across a very succinct summary of the advantages and limitations of Observational Gait Analysis, the subjective method prosthetist-orthotists worldwide use to make judgments about the adjustment, alignment, and configuration of components in the devices we provide. This information is paraphrased from "The Gait Keeper" newsletter # 6 published by the Motion Analysis Center of Mary Free Bed Hospital in Grand Rapids, MI. The entire newsletter is posted at www.mfbrc.com/MAC/MACFallWinter2000.htm.
Observational Gait Analysis has the advantages of being low cost, quick, and simple to perform. Major disadvantages are that it is difficult or impossible to see motion across planes, and OGA requires a great deal of training and practice for proficiency. For gross movement problems, OGA is often quite appropriate, but it is virtually impossible to see small deviations with the unaided eye. Slow motion digital video can be used to supplement simple observation, but the results are still often equivocal. The folks at Rancho have put together an excellent course to teach clinicians how to systematize OGA. Unfortunately, as noted in this newsletter, the validity and reliability of OGA has never been shown to be higher than moderate.
Instrumented, Computerized Gait Analysis gives the clinician objective tri-dimensional information with good reliability and validity, and thus overcomes the major limitations of OGA. Instrumented CGA also makes "invisible" information - such as forces, moments, and muscle activity - readily apparent. This latter advantage is particularly important in P&O: we cannot see that one amputee is stabilizing his knee with his glutes, even though it is aligned with insufficient inherent stability. We can only recognize knee instability [for example], when it is sufficiently severe that the patient complains or we see the "knee jiggle" as he struggles to control the device. The lack of precision in OGA is why we routinely make small alignment changes after the delivery of the prosthesis, when the patient's longer term experience helps reveal small inadequacies in the function of their artificial limb.
On the negative side, in addition to the upfront costs of hundreds of thousands dollars to equip a state-of-the-art computerized gait lab, CGA takes far longer to set up, the gait trials must be conducted by specialized expert staff, and it is therefore far more costly than OGA. As a practical matter, instrumented CGA is probably most valuable when there are complex gait deviations that are difficult or impossible to see clearly with the unaided eye. But, as the cost of gait lab equipment continues to steadily drop, we should begin to see more and more clinicians with access to objective gait data to supplement and refine their treatment recommendations.
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VA Long Beach Conference on Clinical Excellence
Dear John,
Just wanted to thank you for your brilliant presentations at the conference, and your superb sense of humor.
Cheers,
Sandy Diamond, Amputee Clinic clinician.
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Re: VA Long Beach Conference on Clinical Excellence
Thanks Sandy. I really enjoyed many of the papers, particularly those that reviewed literature in areas where I am not as current as I would like to be. --John Michael CPO
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Saludos
Saludos. Mi nombre es Reinaldo Nessi. PO., Caracas, Venezuela. He recibido con agrado la ultima edicion de John Michael's Corner, y su traduccion al espanol por el colega Alberto Castillo, sobre todo quisiera saber si es posible ahondar m... read more
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Re: Saludos
Hola Reinaldo,supongo que te acuerdas de mi,soy un paciente tuyo del Hospital Ortopedico Infantil,con una protesis miolectrica,debido a un explosivo,he estado tratando de ubicarte desde hace tiempo por problemas que he tenido con la prot... read more
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Re: Saludos
Thank you for your comments and suggestions, Sr. Nessi. The topics in the Corners are not selected in advance but depend primarily on what topics of interest I have encountered in prior weeks or months. But, I will keep my eyes open for m... read more
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Marcha Patologica y Biomecanica de la Extremidad Superior.
Ciudad de Mexico 24 de Enero, 2003.
Estimados John Michael y Reinaldo Nessi:
quizas uno de los tratados mas interesantes sobre Marcha Patologica se encuentra en el "Atlas of Orthotics - Biomechanical Principles and Application" de la Acad... read more
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Re: Marcha Patologica y Biomecanica de la Extremidad Superior.
Thanks very much for suggesting these classic references. --John Michael CPO
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La Academia Americana de Ortesistas y Protesistas Invita a su Reunion Anual
Ciudad de Mexico 29 de Enero, 2003.
Estimado John Michael, CPO, FAAOP, FISPO:
La Academia Americana de Ortesistas y Protesistas (AAOP) invita a los profesionales en Ortesis y Prótesis Latinoamericanos a atender su Reunión Anual y Simposi... read more
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