Gait analysis report


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A comparative report on the current different methods of gait analysis from a clinical perspective.

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Gait analysis report

  1. 1. Gait analysis, A Comparative Report: By Conor Sheehan University of StrathclydeThere are several different methods in commonly used, is observational analysisexamining gait and different ways in by a trained professional. This is wherewhich they are graded or assessed, from the examiner will look for anystandard viewing with use of a gait score discrepancies with the person in questionscard, right up to 3D computerised gait, in comparison to that of a normalinstruments. Using the IMRAD report one, some areas that are checked includemodel the following evidence and facts the foot position, which muscles are firingdescribe, some of main methods used in (are active), time of stance and swingpractice for the analysis of gait: phase, etc. This technique is also sometimes combined with the use of aThe key areas that will be focused on in digital camera system that is used forthis report include: visual gait analysis, the recording and playback, for further studyVicon Nexus system and the CODA system of a subject’s gait. Also as previouslyas well as the Kistler force plate which can mentioned a score card is sometimesbe used in conjunction with any of the used, such an example is the Edinburghabove systems. Discussed will be how visual gait scoring chart that helps to focussome of the named systems work or how in on the different areas of the gait cycle.they analyse gait, along with the The main reason this is the mostadvantages and disadvantages frequently used practice is the fact that itrespectively. Each method will first be is low cost and a relatively quick way ofdescribed as an individual area before assessing someone. There do remainbeing compared against one another. some drawbacks to this though, such as:The first method that will be described,which is also the simplest and mostConor SheehanUniversity of Strathclyde, 2010
  2. 2. In real time the human eye is not landmarks on the subject, such an fast enough to pick up on some example is the Vicon Nexus system. It problem areas works by having a number of the specially Observations may not be designed cameras (usually between 6 and quantitative or objective 12) placed round a walkway or treadmill, Subjects may fatigue if having to where a patient will walk and data is walk for long lengths of time, this picked up from each camera, feeding back could then change their walking information to a main computer. The pattern cameras used are part of the Vicon companies T-series range which states theThe use of a camera can help in reducing cameras to be high resolution, high speedthese errors, allowing multiple viewing of and highly accurate. The cameras work bythe same person’s gait an unlimited shining an infrared (IR) beam that pick upamount of times, the video can also be on markers that have been placed onslowed to frame by frame steps for very anatomical landmarks of the subject, suchclear and precise viewing. However they as profound bony landmarks (iliac spines,do bring some of their own problems, like, the malleoli of the ankle, the knee etc.)the true angles made by the subject’s limb the IR light then reflects back off theor the position of the ground reaction markers back into the camera. At any oneforce (GRF) may not be seen as they truly time there are at least two camerasare. The cameras must also be positioned locked on to any one marker, this is for acorrectly and images recorded from both greater information consistency, the datathe coronal and sagittal planes. Finally the is then fed back to a computer wherecamera usually only remains stationary software, “Nexus” in the case in of theand so can only capture the person Vicon Corporation, can produce a 3Dwalking within a certain area of the image of the sighted object. The programsituated camera. can similarly calculate the velocity andThere are also more complex digital acceleration of a moving limb/prosthesissystems that use several cameras to give a being worn; it can then display this3-D shape of the subject and they can be information in a variety of ways. From aused to pick up and located positioned 2D or 3D animation that itself can beConor SheehanUniversity of Strathclyde, 2010
  3. 3. moved and viewed from any angle or extremely expensive to install andplane as well as being slowed or sped up. upkeep, it needs a skilled operator andThe rest of the output information can although fast at processing it is still moredisplay information on body angle time consuming than observational gaitmovements, where they peak and fall analysis and may not necessarily be ablethroughout the different phases of gait, to provide any extra information thathow long these peaks last for etc. would be of significance to the patient, than that of a trained professionals eyeThe Vicon Nexus system is probably the could. Finally a lot more space is neededmost advanced systems for use in the for both the hard and software to be setstudy of gait, in comparison to the other up and used.named methods. As stated it is extremelyaccurate and fast at processing Moving on to the CODA (Cartesianinformation. Furthermore, according to Optoelectronic Dynamic Anthropometer)Vicon, the set up and use of the software system, which is another type of videois easier to use than previous generation vector system with much of the sameof the equipment, “Unlike other Gait functions as the Vicon system. It differs inAnalysis systems, working with Vicon’s T- a number of ways though, primarily thisSeries system doesn’t require an being, as stated by Codamotion itsengineering degree.”(2011, web) producer, it is a portable device. AlthoughHowever, this may be slight bias of the this may be the case, most clinics where itcompany as this still only applies to a is used keep it remaining in a stationary,skilled person/technician who knows and fixed position. Also unlike Vicon needingunderstands the usage of the equipment. several cameras positioned round theThe markers are also considered to be walking area of the subject, the CODAmore confortable to wear for the patient, only need one cx1 unit, which is the baseby Vicon, as the indicators are designed to system containing the cameras. From thisbe light and as they are only required to alone it can “create 3D measurementsreflect the infrared light, not have to without the reference of other camerasproduce it themselves like other video units” (Codamotion, 2011); howeversystems, described later. The systems multiple units can be combined to give amain disadvantage is the product is more accurate image. Also to compensateConor SheehanUniversity of Strathclyde, 2010
  4. 4. for the lack of surrounding cameras, the lot fewer parts that need to be assembledsensors have a wider viewing lens, and positioned with all the mainapproximately 80 degrees. The markers components remaining in the single basethat are attached to the patient also unit. While the use of the softwarediffer; first they are known as active equipment still requires somemarkers as they produce their own light understanding before use. According to asource, rather than reflecting one Dr Barry Meadows, head ofproduced by the camera. Due to this Neurobiomechanics at WESTMARK, SGH,though the active markers need an the CODA analytical software can beattached power source known as a taught to someone usually within a day.DriveBox this does make for a more bulky This being in contrast to the “Nexus”, thatand heavier wear for the user as well as he said could take up to a week to learn.the fact that wires are needed to attach Continuing on to the Kistler force plate,the markers and DriveBox. The advantage which is a flat moving plate usually builtof this method though is the marker can into the ground of a gait lab and usuallybe programed to know what landmark it is designed to match the flooring as not toand so cannot shift or be confused by the influence the walkers gait or foot as another anatomical region, The plate can be made in a number offurthermore if the marker is somehow sizes and in the shape of a single slab, buthidden from the sensor by another part of more often it is divided into two, four orthe body, the system and software can more segments. The reason for this is,calculate to an highly accurate point the allowing a greater area to place the footposition of where the marker is in relation and the potential ability to get the GRF onto the other selected points. both feet without having the subject haveMuch like its competitor, Vicon, the to walk twice and hit the plate with theoutput traits are much the same. It claims opposite side. It is probably the mostthe software and setup are easier to use, important component in measuring gait.“Working with the Codamotion System Though independently it doesn’t servedoesnt require an engineering degree” much of a purpose, it can be used in(Codamotion, 2011). This may well be true conjunction with the above to calculateto an extent for the setup, as there are a the ground reaction force applied by theConor SheehanUniversity of Strathclyde, 2010
  5. 5. person and position of the foot, what part correctly stated by Dr Barry Meadows it isof the foot is being used during initial a quicker and less perplexing system tocontact and through stance to toe off of learn.that foot. With the aid of a specifically set Although both the above methods areup camera it can also show the direction proven to be better than the conventionaland/or magnitude of where the GRF is in visual gait examination and even with therelation to the person on the force plate, allowance of the extra time taken intosometimes this is only done visually with consideration to use either system, it stillthe length of an indicated arrow on a seems that they would be the more logicalcomputer screen, others it will give the practice used. This remains not the caseactual force applied as a number, or due to their high cost which currently atsometimes both ways. the moment cannot be afforded by mostFrom the above finding it is clear that the institutes and clinics, also as the moreevidence shows either the Vicon Nexus or advanced methods take longer to run forCODA systems with the aid of the Kistler each patient this is seen as not an efficientforce plate are both very equally matched use of time and so is another reason usedin use of gait analysis and have a very high against the use of them. Finally at thedegree of accuracy if used correctly. The moment as a skilled clinician can usuallyfact the Vicon system has the greater give just as good a result in determiningnumber of cameras with a wider viewing the main problematic areas and gaitsight due to the positioning of the deviations. So it seems unlikely thatcameras it is overall the more superior of anything will change until there is athe two giving a better three-dimensional drastic diminishing in the cost of theseimage. It does appear though, that the innovative systems, the time spent toCODA technology has a few extra added assess a patient is reduced or there arebenefits over its counterpart, with it extreme advances in the technology that“technically” being mobile, only needing makes gauging gait significantly betterthe one base cx1 unit to function thus than the eye of a professional.resulting in less space consumption and ifConor SheehanUniversity of Strathclyde, 2010
  6. 6. Reference List: Figgins, E. 2010, Human Locomotion 6, Observing Gait, National Centre For Prosthetics and Orthotics Meadows, B. 2011, Slide 7, Gait analysis comes in many forms, WESTMARC, SGH Codamotion. 2010a, Advantages & Capabilities [online]. Charnwood Dynamics Ltd, Available at: [6th March 2011]. Codamotion. 2010b, Movement Analysis With CODA – Overview [online]. Charnwood Dynamics Ltd, Available at: [6th March 2011]. Kistler. 2011a, Motion and gait analysis [online]. Kistler Holding AG, Available at: analysis.html [7th March 2011]. Kistler. 2011b, Why Kistler force plates? [online]. Kistler Holding AG, Available at: plates.html [7th March 2011]. Vicon. 2011a, Gait Analysis+Rehabilitation[online]. OMG plc, Available at: [6th March 2011]. Vicon. 2011b, Vicon Nexus [online]. OMG plc, Available at: [5th March 2011]. Vicon. 2011c, Vicon T-Series and T-Series S Edition[online]. OMG plc, Available at: [5th March 2011]. Wikipedia. 2011, Gait analysis [online]. Available at: [9th March 2011]. Wikipedia. 2011, IMRAD [online]. Available at: [8th March 2011].Conor SheehanUniversity of Strathclyde, 2010