Version 5.0

Instructions for Use
in accordance with
the Medical Devices Directive 93/42/EEC as amended by
EU Council Directive 2007/47/EC of 5^th September 2007

View/download a PDF of this document in English, Italian, French, German or Spanish.

Descriptions of the meaning of symbols used to BS EN ISO 15223-1:2016 - Medical devices - Symbols to be used with medical device labels, labeling and information to be supplied - Part 1: General requirements is at Annex A.

Contents

Trade name of applicable devices

Product trade name of the devices

CLASS I Measuring Devices:

• Vicon Vantage system
• Vicon Vero system

Registered trade name of the manufacturer and the address of its registered place of business

Trade name and address of manufacturer

Vicon Motion Systems Ltd (trading as Vicon)
Unit 6, Oxford Industrial Park,
Mead Road,
Yarnton OXON OX5 1QU
United Kingdom

Registered trade name of the authorized representative and the address of its registered place of business

Trade name and address of authorized representative

GPEM srl
Via Remartello 49 / F
Loreto Aprutino
65014 Pescara
Italy

Intended purpose

Intended use/purpose

Vicon Gait Analysis Systems are intended to provide information which is used to take decisions for therapeutic purposes and to aid in the understanding of the etiology of gait abnormalities resulting from a diagnosis of cerebral palsy or Duchenne muscular dystrophy among presenting children and adolescent patients. The interpretation of resulting kinematic and optional kinetic and electro-myographic data remains in the hands of interdisciplinary teams of health care professionals and biomechanists with substantial knowledge of normal and pathologic human gait where characteristics are measured, abnormalities are identified, causes are postulated, and treatments are proposed. The same technology is routinely applied to establish the efficacy of orthoses and prostheses, and during rehabilitation among the wider population. The purpose is to improve the efficiency of patient ambulatory locomotion [1].

Target patient population

Gait analysis is appropriate for guiding decision-making on management in such disorders as cerebral palsy, stroke, traumatic brain injury and myelomeningocele, Duchenne’s muscular dystrophy patients; artificial limb fitting services.

Contraindications

None

Warnings/cautions

The devices use infrared/near infrared light to illuminate the markers. Photobiological safety calculations made and published to minimize impact.

Expected clinical benefits

Specification of the clinical benefits to be expected

Quantitative clinical gait analysis

Derived from the 2002 seminal work of Davis RB, Õunpuu S, DeLuca PA, Romness MJ, Clinical Gait Analysis and Its Role in Treatment Decision-Making [1] and of David Sutherland’s review on the evolution of clinical gait analysis with a focus on kinematics [2] and kinetics [3].

Since 1984, Vicon Motion Systems has captured and reconstructed the three-dimensional spatial and temporal location of retroreflective markers applied to palpated surface anatomy landmarks to derive and describe an estimation of the motion of underlying joints and bone segments. This is achieved with independently validated clinical gait models outside the scope of this evaluation. The company publishes within declarations of conformity of optical reconstruction performance (kinematics) and analogue to digital performance to facilitate ingestion of approved third-party ground reaction forces (kinetics) and electromyographic voltages. The company products are further tested to ensure optical and analogue data are synchronized to within one video frame.

The goal of clinical gait analysis is to assist in treatment decision-making for a patient with complex and not easily understood walking problems. Quantitative clinical gait analysis is a process whereby gait characteristics are measured, abnormalities are identified, causes are postulated, and treatments are proposed. The approach involves the placement of external markers or targets at specific points on the lower extremities and torso of the patient. These markers are then monitored by video cameras as the patient walks along a straight, level pathway. The two-dimensional camera images are analysed by a central collection computer incorporating validated photogrammetric reconstruction algorithms to quantify the movement of specific joints and body segments in three-dimensonal space. For example, by measuring the thigh and shank simultaneously, you can appreciate knee motion.

This analysis of motion can be combined with measures of muscle activity and the reaction forces between the patient's foot and the ground, to provide a comprehensive assessment of the biomechanics of locomotion.

It is important to appreciate that while quantitative gait analysis uses technology to measure gait patterns, it does not replace the human observer (ie, the observational gait analysis approach that a clinician might employ in a clinic or office setting). Rather, clinical gait analysis serves as an adjunct to aid understanding – more precisely and at times more accurately – of visual impressions of a patient's gait impairment. Through the thoughtful use of technology, quantitative gait analysis provides an opportunity to appreciate the details of complex movement patterns that may involve a number of lower (and upper) extremity joints and segments simultaneously and include movements that occur in several planes of motion concurrently, as well as to understand and correlate the associated muscle activity.

It is also important to understand that while treatment decision-making is facilitated by clinical gait analysis, these decisions are always made in the context of the clinician's experience in gait analysis and in the management of the particular disorder presented by the patient. Quantitative gait analysis does not dictate clinical treatment. Although patients seen most often for gait analysis present with complex and sometimes subtle gait deviations that suggest surgical intervention is necessary, other recommendations for management may include physiotherapy exercises, bracing (orthoses), spasmolytic medications (such as, Botulinum toxin, baclofen), or condition monitoring.

The objectives of this report are to illustrate to the reader the process of clinical gait analysis and to clarify when it might be of benefit for individuals with walking concerns. Several questions commonly asked about clinical gait analysis are addressed, including:

Summary

In summary, quantitative gait analysis provides the tools necessary to evaluate both normal and pathologic 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 patient's gait pattern. Proper gait data interpretation is dependent upon the care with which gait data are collected and the experience and expertise of the clinical team, which may include physicians, clinical scientists, physiotherapists, kinesiologists, engineers and technicians.

Summary of safety and clinical performance

Risks

Risk analyses compliant to ISO 14971:2019: Application of risk management to medical devices are completed for all product offerings. Copies are available upon request.
Exclusions: Not for use in an operating theatre, anesthetic gas or oxygen-rich environments. Not for use where there is a risk of compromising the general safety and performance of medical electrical equipment. Not suitable for use in high magnetic flux, ionizing radiation, sterile, or life- or safety-critical environments.

• The risks (from risk management and literature) have been addressed by the following clinical data:
  None identified. There have been no Adverse Incident reports or risks identified in routine Post Market Surveillance reports in any country since the product launches in 2015 (Vantage system) and 2016 (Vero system). Supporting software has been in service since 2007.
  
  
• All hazards and other clinically relevant information have been identified appropriately. They are as follows:
  

  Misuse of software where measurement performance does not meet specification or misinterpretation of data.

  Reasonably foreseeable misuse: 
  

  • Use of a system in a way not intended by the manufacturer, but which can result from readily predictable human behaviour.

  • Readily predictable human behaviour includes the behaviour of all types of users, e.g. lay and professional users.

  • Reasonably foreseeable misuse can be intentional or unintentional.

  The most likely risk is that the health professionals, biomechanists or medical practitioners are not anatomically competent to correctly place the markers using palpation, which may result in erroneous results that may affect therapeutic decision-making.

  The second most likely risk is that the health professionals, biomechanists or medical practitioners are not clinically competent to interpret the information in therapeutic decision-making.
  
  

• The safety characteristics and intended use (purpose) of the device requires training of the end-user.
  Yes
  
  
• The safety characteristics and intended use (purpose) of the device requires the following precautions:
  The devices use infrared/near infrared light to illuminate the markers. Photobiological safety calculations are made and published to minimize impact. This is achieved through notices in the supporting manuals and on the applicable equipment labels.
  
  
• The foreseen users of the device are adequate. They are as follows.
  Medical practitioners, orthopedic surgeons, clinical scientists, physiotherapists, kinesiologists, biomechanists, engineers and technicians
  The equipment is not designed for use by lay persons or patients when meeting its intended purpose.
  
  
• All training requirements and precautions are listed.
  The devices use infrared/near infrared light to illuminate the markers. Photobiological safety calculations are made and published to minimize impact. Safe use is achieved through notices in the supporting manuals and on the applicable equipment labels.
  

  Clear guidance is provided through documentation and on-site user training prior to use. The Manufacturer provides post-installation and training, on-line and personal technical support, including review of data to minimize usage errors and incorrect interpretations of results.  

  Users are recommended to become members of the manufacturer agnostic  ESMAC – European Society for Movement analysis in Adults and Children in Europe (esmac.org) and/or CMAS – Clinical Movement Analysis Societyof  UK & Ireland (cmasuki.org) for clinical focussed training and education. Both societies offer laboratory accreditation, standards and courses. 

  The Software is not intended to replace the clinical skill of a medical practitioner or his/her independent professional judgement of individual clinical circumstances to determine a patient's treatment. The Software should only be used by those who have been appropriately trained in its operation, functions, capabilities and limitations, and in any event should not be relied upon, by itself, as the sole method of making any diagnosis or determining any treatment.
  
  

• There is full consistency between current knowledge/the state of the art, the available clinical data, the manufacturer's product information, and the risk management documentation for the device.
  Yes
  
  
• Summary of the total experience with the device, including numbers and characteristics of patients exposed to the device and duration of follow-up in:
  • Other user experience: Through published literature
  • Market experience: Through published literature including systematic reviews [29]
    
    
• Nature, extent/severity, probability, duration of benefits to the patients and of side effects and other risks.
  No identified side effects
  
  
• For each aspect of the intended use, whether the benefit/risk profile including its uncertainties is compatible with a high level of protection of health and safety, corresponding justifications.
  

  The benefits of clinical gait analysis when drawing on quantifiable kinematic, kinetic and electromyographic data are summarized below. The independent conclusion presented is with the caveat that the effect of gait analysis on patient outcomes is less well established in the absence of a randomized controlled trial. However, multiple cohort comparisons and a case-control study strongly suggest that gait and functional outcomes are improved when treatment follows gait analysis recommendations in conjunctions with physical clinical assessments. The assessment in this report is that based on the presented peer reviewed evidence the benefits of gait analysis are positive. The review of the proposed risk controls in conjunction with post market surveillance and customer complaint and feedback evidence establishes that the overall Benefit-Risk Ratio is assessed not adversely affected by any residual risks.
  
  Clinical gait analysis includes a physical examination, motion tracking of body segments (kinematics), recording of ground reaction forces (kinetics) between the feet and floor, and electromyography. Motions, forces, and muscle firing patterns are measured to assess the patient’s status and to develop an appropriate treatment plan. Each component of gait analysis testing can be performed separately, but the data are most useful when viewed together in a comprehensive evaluation.
  
  Gait analysis allows for a more accurate assessment of gait deviations than visual gait assessment [30,31] to provide quantifiable information in the management of a patients with walking problems. A number of studies have demonstrated that gait analysis alters surgical decision-making and changes the treatment patients receive [32– 35]. The studies generally compare treatment plans without gait analysis to treatment plans for the same patients that do utilize gait analysis. Most studies have focused on the use of pre-operative gait analysis in surgical planning for children with cerebral palsy and other diagnoses or in patients with specific impairments like spastic equinovarus [33] One study examined post-operative treatments including bracing, physical therapy, and additional surgery [36]. In some studies, the two treatment plans being compared (with and without gait analysis) are proposed by the same clinician [32,33]. In other studies, the plan without gait analysis is proposed by a referring physician, and the plan with gait analysis is proposed by the gait laboratory team, which may or may not include the referring physician [34,35]. The findings have been consistent, regardless of the details of the study design.
  
  The results of these studies indicate that the treatment plans with and without gait analysis differ in a high percentage of patients (52% to 89%) and procedures (40% to 51%) [32–36] In addition, in patients undergoing gait analysis there are changes between the initial treatment plan and the treatment ultimately performed. Two of these studies found that 37% to 39% of the procedures planned before gait analysis were not ultimately done, and 28% to 40% of the procedures actually done were not planned before gait analysis [34,35] The change in actual treatment is likely due, at least in part, to the addition of gait analysis since gait analysis recommendations are followed in a high percentage of patients (with 77% having an exact match between the surgeries recommended by gait analysis and the surgeries ultimately performed [37]) and specific surgical procedures (92% to 93%) [35,37].
  
  Several studies have evaluated the effect of gait analysis on patient outcomes [38–43]. These studies generally compare outcomes between patients whose treatment followed gait analysis recommendations and patients whose treatment did not follow gait analysis recommendations. The results indicate better gait and functional outcomes when the treatment follows gait analysis recommendations. Specifically, function improves when surgery is done and is consistent with gait analysis recommendations, function is maintained when no surgery is done as recommended by gait analysis, and function deteriorates when surgery is recommended by gait analysis but not done. 
  
  The first study of this type graded outcomes as improved or not improved based on temporal and sagittal gait parameters in a small number (n=22) of children with spastic diplegic cerebral palsy [40]. Of 15 children who had surgery in accordance with gait analysis recommendations, 13 improved, and two did not improve because the outcome measures did not capture the impairment being addressed (rotational alignment). Of seven patients who did not have the recommended surgeries performed, two had surgeries similar to those recommended by gait analysis and improved, while the other five had surgeries different from the gait analysis recommendations and did not improve. This study provided the first indication that patients may have better outcomes when their treatment follows gait analysis recommendations.
  
  Several recent studies have continued this line of investigation, comparing groups of patients with CP whose treatment followed gait analysis recommendations to different extents. Gough and Shortland [43] reported that outcome measures related to contracture and gait improved in children who had multilevel surgery as recommended by gait analysis, worsened in children who did not undergo surgery despite having surgery recommended by gait analysis, and remained stable in children who had no surgery as recommended by gait analysis. Filho et al. [39] observed improvement in gait in surgical patients whose surgery agreed, to some extent, with gait analysis recommendations. The significance of the improvement was related to the degree to which the gait analysis recommendations were followed, and no improvement was observed in patients who had surgical or non-surgical treatment that was completely different from that recommended by gait analysis. Lofterod et al. [41] reported satisfactory kinematic outcomes in pediatric gait laboratory patients who received surgical or non-surgical treatment consistent with gait analysis recommendations. These studies suggest that gait analysis is useful in defining indications for surgical and non-surgical treatment and that treatment following gait analysis recommendations is associated with better outcomes.
  
  One study has compared outcomes during periods before and after gait analysis was added to the management protocol for children with cerebral palsy [44]. 122 two patients managed without gait analysis from 1985 to 1989 were compared against 170 patients managed with input from gait analysis from 1996 to 1997 (after the gait analysis equipment and methodology were fully established). The patients managed with gait analysis had a lower prevalence of surgery at all ages as well as a lower rate of multiple surgeries, suggesting that surgeries were delayed or avoided when gait analysis was included in the patient management protocol.
  
  Finally, one case-control study matched 10 children with cerebral palsy who had surgery in accordance with gait analysis recommendations to 10 children who had the same surgeries recommended but no surgery done [38]. The children who were operated on as recommended by gait analysis had a significantly higher percentage of patients with positive outcomes based on surgery-specific kinematic criteria (44% vs. 26%, p<.0001), with an odds ratio for positive outcome of 3.7 (95% confidence interval: 2.0–7.0). Thus, the likelihood of a positive outcome was significantly greater when surgery was performed as recommended by gait analysis.
  
  The impact of gait analysis on treatment decision-making is well established through multiple comparative studies and a recent randomized controlled trial. Gait analysis has two primary effects on decision-making: changing decisions when the gait analysis results disagree with the original treatment plan and reinforcing decisions when the gait analysis results agree with the original plan. Gait analysis influences both the physician’s diagnostic thinking and, ultimately, the treatment received by the patient.
  
  The effect of gait analysis on patient outcomes is less well established in the absence of a randomized controlled trial. However, multiple cohort comparisons and a case-control study strongly suggest that gait and functional outcomes are improved when treatment follows gait analysis recommendations in conjunctions with physical clinical assessments.
  
  The equipment is inherently safe as it does not make any contact with the patient except with hypoallergenic, latex-free wig tape and Micropore® tape to attach markers to skin.
  
  

• Extent to which assessment of benefits is possible based on available data, limitations of the data, description of gaps, uncertainties, and assumptions.
  Identified within systematic review [29]
  
  
• Whether available data allows adequate assessment of performance, limitations of the data, gaps, and uncertainties.
  Yes
  
  
• Whether there is sufficient evidence for every intended performance.
  Yes
  
  
• Whether the data available is of sufficient amount and quality for the detection of side effects and their frequency, limitations of the data, description of gaps, uncertainties, and assumptions.
  Yes
  
  
• Whether the side effects are acceptable and corresponding justifications.
  Yes, none identified
  
  
• The benefit/risk profile according to current knowledge/the state of the art in the medical fields concerned and according to available medical alternatives is acceptable.
  The intended use and corresponding risk reduction measures are adequate and the product information is suitable for the intended users and sufficiently covers all usability aspects.
  
  Exclusions: Not for use in an operating theatre, anesthetic gas or oxygen-rich environments. Not for use where there is a risk of compromising the general safety and performance of medical electrical equipment. Not suitable for use in high magnetic flux, ionizing radiation, sterile, or life- or safety-critical environments.
  
  Note: The overall system classification is defined by the highest risk device installed that may include the addition of approved third-party equipment such as electromyography apparatus by clients. 
  
  
• All claims foreseen by the manufacturer are identified and any discrepancy and gaps are fully covered by clinical data.
  There is full consistency between the clinical data, the information materials supplied by the manufacturer and the risk management documentation for the device under evaluation.
  
  
• Residual risks and uncertainties are sufficiently identified. The acceptability for CE-marking is sufficiently discussed and follow-up measures during PMS are addressed. (This includes uncertainties regarding medium- and long-term performance, safety under widespread use, residual risks such as side-effects and complications occurring at rates below detection possibilities of currently available clinical data, others).
  Risks and uncertainties are already addressed in ongoing PMS activities (eg, in currently ongoing reviews in the literature).

Performance characteristics of the device

Performance characteristics

Measurement definitions applied

Within this instruction, accuracy is defined as to how close measurements are to a known true value, while precision refers to how close measurements are to each other. In other words, accuracy describes the difference between the measurement and actual value, while precision describes the variation observed when measures of the same marker location or parameter are repeated with a Vicon motion capture system. Precision is described by two sub-components:

• Repeatability: The variation observed when the same system measures the same location or parameter repeatedly.
• Reproducibility: The variation observed when different systems measure the same location or parameter repeatedly.

Soft tissue artifact

The engineering and physics problem of capturing and tracking 3D points in space has been solved and well understood within Vicon motion capture systems. However, clinical concerns remain over the loose association between the measurements of points on the skin surface and the underlying bone, commonly described as the soft tissue artefact [47]. Challenges also remain in reliably capturing bony landmark axial rotation, in particular, of the thigh [48].

Due to inaccuracies related to working with biological systems [49], there are limitations in the way 3D motion data are acquired. Markers attached to the skin move with respect to the underlying bones that they are intended to represent. Soft tissue artifact (STA) arises from movement or deformation of the subcutaneous tissues associated with muscular contractions, skin movement and inertial effects. The extent of STA for any movement depends upon the physical characteristics of individuals, marker locations and the nature of the movement task performed.

Many researchers and gait laboratories have proposed techniques to move away from existing predictive approaches by instead discovering joint centers and axes functionally, and fitting the data to an idealized joint model that also incorporates some form of soft tissue artifact compensation. This work continues and, like the earlier innovations, will gain wide acceptance only after it has been validated through close collaborative efforts between clinicians, scientists and engineers in laboratories, academia and industry.

To ensure where possible that spatio-temporal marker measurement artifact is not introduced into the wider problem, Vicon motion capture systems are designed to achieve performance in all variants to always be below the anticipated soft tissue artifact. The performance upper limit is defined within the published Declaration of Conformity and is common for all published CLASS Im product offerings.

Charlton et al [47] estimated that when developing human lower limb biomechanical models, marker location covariance was estimated to be 10 mm² in all coordinate directions.

Peters et al [49] undertook a systematic review to critically evaluate the quantification of STA in lower limb human motion analysis. It has a specific focus on assessing the quality of previous studies and comparing quantitative results. A specific search strategy identified 20 published articles or abstracts that fulfilled the selection criteria. The quality of the articles was evaluated using a customized critical appraisal tool. Data extraction tools were used to identify key aspects reported in the articles. Most studies had small sample sizes of mostly young, slim participants. Eleven of the reviewed articles used physically invasive techniques to assess STA. STA was found to reach magnitudes of greater than 30 mm on the thigh segment, and up to 15 mm on the tibia. The range of soft tissue artifact reached greater than 25 mm in some cases when comparing the results of reviewed studies.

Information allowing the healthcare professional to verify if the device is suitable

Selection and verification of device suitability

Independent protocol for quantifying the accuracy of motion analysis systems

The Gait and Clinical Motion Analysis Standards Council (GCMAS) has proposed a protocol for quantifying the accuracy of a motion analysis system (ie, how accurate the system is at locating markers). This Standard Assessment of Motion System Accuracy protocol (SAMSA) is intended to test video-based systems that employ reflective markers.

SAMSA uses a simple device based on an earlier design used by Jim Richards to compare motion systems [50]. This device consists of a beam fitted with markers and rotated at 60 RPM by a motor. The protocol is designed to test the ability of a motion system to (1) track moving markers; (2) resolve markers using a subset of the cameras; and (3) resolve markers that pass close to one another during a trial. The protocol has been tested in the laboratories of seven Standards Committee members and the results have been used to formulate an accuracy standard in the form of acceptable error thresholds. This testing and the error thresholds were presented at the 2007 GCMAS Meeting in Springfield [51] and found to be between 0.21–3.50 mm Mean; 0.08–3.86 mm SD, independent of equipment supplier.

Independent static and dynamic performance evaluation of a Vicon system

Merriaux et al [52] used a very similar apparatus to study the positioning performance of an eight-camera Vicon T-Series system. Their protocol included evaluations of static and dynamic performances. Mean error, as well as positioning variabilities, were studied with calibrated ground truth setups that are not based on other motion capture modalities. They introduce a new setup that enables directly estimating the absolute positioning accuracy for dynamic experiments, contrary to state-of-the art works that rely on inter-marker distances. The system performed as expected on static experiments with a mean absolute error of 0.15 mm and a variability lower than 0.025 mm. The dynamic experiments were carried out at speeds found in real applications. The work suggests that the system error is less than 2 mm. The authors also reported that marker size and Vicon sampling rate must be carefully chosen with respect to the speed encountered in the application in order to reach optimal positioning performance that can go to 0.3 mm for the dynamic study.

ASTM Standard E304-16 Test method for evaluating the performance of optical tracking systems that measure six degrees of freedom (6DoF) pose

ASTM has recently published a standardized test method that presents metrics and procedures for measuring, analysing, and reporting the relative pose error of optical tracking systems that compute the pose (ie, position and orientation) of a rigid object while the object is moving. Following their protocol [52], experimental results using a 12-camera Vicon system confirmed that distance errors lay in most data at below ± 0.5 mm and angle errors < 0.36°, consistent with the findings of Bostelman et al [53], using a system from another supplier (Optitrak).

Degree of accuracy claimed for all generic devices

Performance characteristics independent of type and configuration

Measurement criteria

Supporting software: Nexus 2.11 or later

Motion capture reconstruction resolution

Using a minumum of four optical motion cameras, resolution of the distance between the centers of two static 14 mm spherical markers located within a volume not less than 4 m x 4 m x 1.5 m to within 1 mm mean; 1 mm Standard Deviation; sample size no less than 1,000.

This equates to one order of magnitude (1 mm³) better than reported skin movement artifact 10 mm³ [47].

Analogue digital conversion

Resolution to ± 10 mV mean and ± 10 mV (1 Standard Deviation)

Outputs from 3rd Party Kinectic and Electromyographic devices is ± 5 V  to ± 10 V. Measurement artifact is assessed at 0.2–0.1% error.

Synchronization

Difference within one video frame

Clinical gait analysis is captured at 120 frames.sec^-1 which equates to 8.3 m sec^-1, maximum potential Motion-Analogue temporal difference.

Details of any preparatory treatment or handling of the device before it is ready for use

Device preparation

Please refer to the supplied user guides for the selected device to prepare the equipment for use. Sterilization and disinfection is not required as the device is excluded for use in these environments.

Facilities and user training

Facilities and user training

Please refer to the supplied user guides.

Clinical gait analysis systems using Vicon motion capture systems and any approved third-party devices or equipment are fixed installations.

Clear guidance is provided through documentation and on-site user training prior to use. The Manufacturer provides post-installation and training, on-line and personal technical support including review of data to minimize usage errors and incorrect interpretations of results.  

Users are recommended to become members of the manufacturer-agnostic  ESMAC – European Society for Movement analysis in Adults and Children in Europe (esmac.org) and/or CMAS – Clinical Movement Analysis Society of UK and Ireland (cmasuki.org) for clinical focussed training and education. Both societies offer laboratory accreditation, standards and courses. 

Gait laboratory staff competencies

A typical gait analysis test can take from one to two hours, depending on the particular evaluations performed and on the cooperation, behaviour, and gait complexity (ie, involvement) of the patient. Usually, a clinical scientist, physiotherapist or kinesiologist works directly with the patient, and a more technically oriented person, such as an engineer or technician, manages the computer and measurement system operation during the test.

Institutional standards

It should be noted that not all clinical gait laboratories operate in this fashion. Some do not have the technology to provide three-dimensional body marker data and analytical processes that produce three-dimensional joint rotations (flexion-extension, abduction-adduction, and internal-external rotation) for interpretation. These clinical gait analysis laboratories use less sophisticated technology that collects and processes motion data based on the assumption that all of the rotations occur in the sagittal plane of the body. This assumes that all motions associated with gait can be appreciated from a side view of the patient. While this might not be unreasonable in the analysis of normal ambulatory motion (except perhaps for ankle/foot motion), it is clearly ill-advised for clinical decision-making in cases of pathological gait where three-dimensional motion is commonplace [54].

Moreover, at other facilities, a clinical gait analysis might be limited to a video recording and the measurement of certain gait stride and temporal parameters such as velocity, cadence, stride length, step length and percentage of stance/swing. While the video record is a useful tool in developing and substantiating visual impressions, it is inappropriate to "measure" joint and segment gait kinematics directly from the two dimensional video imagery, even though some commercially available hardware and software products do this. With respect to stride and temporal parameters, these are "outcome" measures and provide an indication of the level of function when compared to normal values. However, they do not give an indication of the cause of the gait abnormality and are, consequently, of limited value in clinical decision-making.

Similarly some laboratories capture only kinematic data so do not have access to the additional insights of kinetic information in their treatment decision-making.

Verification the device is ready to perform safely and as intended

Device verification

Please refer to the supplied user guides for the selected device for:

• Information needed to verify whether the device is properly installed and is ready to perform safely and as intended
• Information on identification of any consumable components and how to replace them
• Information on any necessary calibration to ensure that the device operates properly and safely during its intended lifetime

Use with third-party approved equipment and devices

Use with third-party equipment and devices

Please refer to the supplied user guides for the selected device for:

• Information to identify such devices or equipment, in order to obtain a safe combination

• Information on any known restrictions to combinations of devices and equipment.

Warnings, exclusions and precautions

Warnings, exclusions and precautions

Please refer to the supplied user guides and Declaration of Conformity for the selected device to address:

• The devices use infrared/near infrared light to illuminate the markers. Photobiological safety calculations made and published to minimize impact. This is achieved through notices in the supporting manuals and on the applicable equipment labels.
• Not for use in an operating theatre, anesthetic gas or oxygen-rich environments. Not for use where there is a risk of compromising the general safety and performance of medical electrical equipment. Not suitable for use in high magnetic flux, ionizing radiation, sterile, or life- or safety-critical environments.
• Emissions and immunity to electromagnetic interference standard compliance are listed within the applicable user guide. Full test reports are available on request.

Serious incident reporting

Serious incident reporting

A notice to the user and/or patient that any serious incident that has occurred in relation to the device should be reported to the manufacturer and the competent authority of the Member State in which the user and/or patient is established. Guidance is located within the regulatory compliance chapters in all user guides and in the Regulatory Information section of the Vicon website.

Information technology security

Information technology security

The system is connected to a dedicated local personal computing device and is managed by executable software within a third-party operating system. All information technology security of assets is at the full discretion of the user and out of scope for the manufacturer.

Date of issue of instructions for use

Instructions for use date of validity

From 8^th February 2021

References

1. Davis RB, Õunpuu S, DeLuca PA, Romness MJ: Clinical Gait Analysis and Its Role in Treatment Decision-Making. MedGenMed 1(1), 1999 [formerly published in Medscape Orthopaedics & Sports Medicine eJournal 2(5), 1998]. Available at: http://www.medscape.com/viewarticle/440148
2. Sutherland DH: The evolution of clinical gait analysis. Part II kinematics, Gait Posture. 2002 Oct; 16(2): 159–79.
3. Sutherland DH: The evolution of clinical gait analysis part III—kinetics and energy assessment. Gait Posture. 2005 Jun; 21(4): 447–61.
4. Perry J: The role of EMG in gait analysis, in Harris GF, Smith PA (Eds): Human Motion Analysis: Current Applications and Future Directions. Piscataway, IEEE Press, 1996, 255–267.
5. Davis R, DeLuca P: Clinical Gait Analysis: Current Methods and Future Directions, in Harris G, Smith P (Ed): Human Motion Analysis: Current Applications and Future Directions. Piscataway, IEEE Press, 1996, 17–42.
6. Ounpuu S, Davis R, DeLuca P: Joint kinetics: methods, interpretation and treatment decision-making in children with cerebral palsy and myelomeningocele. Gait and Posture 4, 1996: 62–78.
7. Ounpuu S: Joint Kinetics: Interpretation and Clinical Decision-making for the Treatment of Gait Abnormalities in Children with Neuromuscular Disorders, in Harris G, Smith P (eds): Human Motion Analysis: Current Applications and Future Directions. Piscataway, IEEE Press, 1996, 268–302.
8. Perry J, Bontrager E, Antonelli D: Foot switch definition of basic gait characteristics, in Kenedi RM, Paul JP, Hughes J (Eds): Disability. Strathclyde Bioengineering Seminars. London, MacMillan Press, 1979, 131–135.
9. Cavanagh PR, Hennig EM, Rogers MM: The measurement of pressure distribution on the plantar surface of diabetic feet, in Whittle M, Harris D (Eds): Biomechanics of Measurement in Orthopaedic Practice. Oxford, Clarendon Press, 1985, 159–166.
10. Rose J, Gamble JG, Medeiros J, et al: Energy cost of walking in normal children and in those with cerebral palsy: comparison of heart rate and oxygen uptake. J Pediatr Orthop 9, 1989: 276–279.
11. Davis RB, Õunpuu S, Tyburski DJ, et al: A comparison of two-dimensional and three-dimensional techniques for the determination of joint rotation angles. International Symposium on 3-D Analysis of Human Movement. Montréal, Canada, 1991: 67–70
12. Leboeuf, F., Baker, R., Barré, A., Reay, J., Jones, R., Sangeux, M.: The conventional gait model, an open-source implementation that reproduces the past but prepares for the future. Gait Posture, 2019; 69 126–129.
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Annex A: Description and meaning of applicable symbols