BlueCross and BlueShield of Montana Medical Policy/Codes
Gait Analysis
Chapter: Therapies
Current Effective Date: June 01, 2013
Original Effective Date: July 01, 1990
Publish Date: June 01, 2013
Revised Dates: April 14, 2004; April 27, 2009, September 1, 2011, April 6, 2012; April 3, 2013
Description

Comprehensive gait analysis is the quantitative laboratory assessment of coordinated muscle function, typically requiring a dedicated facility and staff.  At its core is the videotaped observation of a patient walking.  Videos can be observed from several visual planes at slow speed, allowing detection of movements not detectable at normal speed.  Joint angles can be measured, and various time-distance variables can be measured including step length, stride length, cadence, and cycle time.  Electromyography (EMG), assessed during walking, measures timing and intensity of muscle contractions.  This calculation allows determination of whether a certain muscle’s activity is normal, out of phase, continuous, or clonic.

Kinematics is the term used to describe movements of joints and limbs such as angular displacement of joints and angular velocities and accelerations of limb segments.  The central element of kinematic assessment is some type of marker system that is used to represent anatomic landmarks, which are then visualized and quantitatively assessed during analysis of videotaped observations.  Movement data are compiled by computer from cameras oriented in several planes, and the movement data are processed so that the motion of joints and limbs can be assessed in three dimensions.  The range and direction of motion of a particular joint can be isolated from all the other simultaneous motions that are occurring during walking.  Graphic plots of individual joint and limb motion as a function of gait phase can be generated.

Kinetics is the term used to describe those factors that cause or control movement.  Evaluating kinetics involves the use of principles of physics and biomechanics to explain the kinematic patterns observed and generate analyses that describe the forces generated during normal and abnormal gait analysis.

Gait analysis has been proposed as an aid in surgical planning, primarily for cerebral palsy.  It is also being investigated as a means to plan rehabilitative strategies for ambulatory problems related to aging, stroke, spinal cord injury, etc.

The Commission for Motion Laboratory Accreditation, a non-profit organization established in 1997, evaluates and accredits motion laboratories within clinical facilities.  A multidisciplinary team uses a set of criteria to evaluate laboratories in the areas of administration (e.g., staffing, policies, and procedures), equipment (e.g., accuracy and precision), and data management and reporting (e.g., control and clinical data sets).

The Electrodynogram™ is one of the many proprietary devices used in gait analysis.  It is a computerized diagnostic device that quantitatively measures and times the coordination of weight-bearing forces and muscular activity exerted on the feet and legs.  In May 2003, the Peak Motus Motion Measurement System (Peak Performance Technologies) was cleared for marketing by the U.S. Food and drug Administration (FDA) through the 510(k) process.  This system uses off-the-shelf video cameras and sensors and proprietary software to document human movement in two- or three-dimensional space.  The FDA determined that this device was substantially equivalent to existing devices and is indicated for assessment and training of limb or body motion in gait analysis, pre- or post-rehabilitation evaluation, physical therapy, and similar applications.

NOTE:  Surface EMG may be used as part of gait analysis, but the two terms are not synonymous.

Policy

Prior authorization is recommended. To authorize, call Blue Cross and Blue Shield of Montana (BCBSMT) Customer Service at 1-800-447-7828 or fax your request to the Medical Review Department at 406-441-4624. A retrospective review will be performed if services are not prior authorized.

Medical Necessity

BCBSMT may consider comprehensive gait analysis medically necessary as an aid in surgical planning in patients with gait disorders associated with cerebral palsy.

Investigational

BCBSMT considers comprehensive gait analysis experimental, investigational and unproven for all other applications, including but not limited to:

  • Surgical planning for conditions other than gait disorders associated with cerebral palsy;
  • Postoperative evaluation of surgical outcomes and rehabilitation planning and/or evaluation for all conditions.

Gait analysis that is not comprehensive is considered experimental, investigational and unproven for all indications.

Federal Mandate

Federal mandate prohibits denial of any drug, device or biological product fully approved by the FDA as investigational for the Federal Employee Program (FEP). In these instances coverage of these FDA-approved technologies are reviewed on the basis of medical necessity alone.
NOTE: Utilize this pre-service request form for FEP pre-service requests for gait analysis (Foot Pressure Measurements).

Policy Guidelines

Gait analysis is sometimes termed dynamic EMG and surface EMG, and may be erroneously submitted on claims under EMG codes.

Rationale for Benefit Administration

This medical policy was developed through consideration of peer reviewed medical literature, FDA approval status, accepted standards of medical practice in Montana, Technology Evaluation Center evaluations, and the concept of medical necessity. BCBSMT reserves the right to make exceptions to policy that benefit the member when advances in technology or new medical information become available.

The purpose of medical policy is to guide coverage decisions and is not intended to influence treatment decisions. Providers are expected to make treatment decisions based on their medical judgment. Blue Cross and Blue Shield of Montana recognizes the rapidly changing nature of technological development and welcomes provider feedback on all medical policies.

When using this policy to determine whether a service, supply or device will be covered, please note that member contract language will take precedence over medical policy when there is a conflict.

Rationale

A 2001 Blue Cross Blue Shield Association (BCBSA) Technology Evaluation Center (TEC) Assessment offered the following observations and conclusions regarding gait analysis for pediatric cerebral palsy:

  • There are no generally recognized standards of performance and interpretation of gait analysis.  Different labs use different computer systems, and there are no standards for training in gait analysis techniques and interpretation.  Comparison between laboratories is difficult, and there could be many interpretations of the same data.
  • Gait analysis has been used extensively as an outcome tool in research on gait, however, much is still unknown about the specific correlation of gait analysis parameters to overall functional status.
  • Gait analysis can be evaluated in terms of accuracy relative to some reference standard, but the available comparators only allow evaluation in a very limited sense.  For example, accuracy of gait analysis in determining some specific parameters of gait such as joint flexion could be compared to clinical observations, and likely show that gait analysis is most reliable and valid.  However, such information is of limited utility in making diagnostic decisions. The purpose of both clinical assessment and gait analysis is not to determine specific quantifiable deficits in gait but to interpret the whole clinical picture and make clinical decisions that result in the best patient outcomes.
  • The scientific evidence directly addressing the question of improved patient outcomes due to gait analysis consists of a single retrospective study of 23 pediatric patients.  In the absence of any well-designed observational or randomized controlled trials, no conclusions can be drawn about whether gait analysis in routine clinical management has an effect on health outcomes.

The 2001 TEC Assessment focused on gait analysis among children with cerebral palsy.  At that time, even less literature existed on gait analysis used in other musculoskeletal disorders.

Due to a lack of standard interpretation of gait analysis and insufficient evidence on its effect on health outcomes, gait analysis was considered investigational for all applications.  The ideal study design to evaluate the utility of gait analysis for surgical planning or evaluation or rehabilitation planning would be a randomized controlled trial comparing health outcomes in patients managed with and without gait analysis.

Accuracy and Reliability

A systematic review of 18 studies on gait classification systems was published in 2007 (Dobson et al.).  The review included studies that involved classification of gait impairment based on kinematic, temporal-spatial kinetic, or electromyographic (EMG) data.  Fifteen studies used three-dimensional gait analysis, one study used video observation analysis and six studies used EMG data.  The authors assessed the overall methodological quality of the studies as low.  Many studies appeared to classify patients arbitrarily rather than by using clear clinical decision-making principles.  Only two studies evaluated the reliability of classification and the methods for determining the validity of classification systems was inadequate.  In an earlier study funded by the United Cerebral Palsy Foundation, four different gait analysis centers gave different treatment recommendations after evaluating the same 11 patients (Noonan et al.)  Thus, there appears to be inconsistency in gait analysis recommendations between some centers.

Impact on Health Outcomes

The ideal study design to evaluate the utility of gait analysis for surgical planning or evaluation or rehabilitation planning would be a randomized controlled trial (RCT) and would compare health outcomes in patients managed with gait analysis to patients managed using another approach.

In 2011, Wren and colleagues published a systematic review of literature on the efficacy of gait analysis.  The authors identified seven studies evaluating the effect of gait analysis on patients’ health outcomes; none were RCTs.  The studies addressed a variety of clinical conditions, and the authors were not able to pool findings.  The systematic review also identified studies evaluating other aspects of gait analysis including technical accuracy, diagnostic accuracy, and societal efficacy (i.e., impact on number and cost of procedures).  The authors concluded that, although there is lower-level evidence (e.g., case series, case-control studies) supporting gait analysis, there is a lack of evidence from RCTs on the effect of gait analysis on health outcomes.

Evidence on specific applications of gait analysis is described below.

Pre- and/or Post-Surgical Evaluation for Children with Cerebral Palsy

A study by Wren and colleagues was identified that compared outcomes in patients managed with and without the use of gait analysis, the preferred study design; however, it was retrospective and patients were not randomized to treatment group (Wren et al., 2009).  The analysis included 462 children with cerebral palsy who had undergone lower extremity orthopedic surgery at a single hospital and had at least six months’ follow-up (n=313 had gait analysis prior to surgery and n=149 did not).  Adjusting for baseline differences, the overall finding was that the number of procedures and costs did not differ significantly between groups.  The group that received gait analysis had a mean of 2.6 procedures per person-year compared to 2.3 per person-year in the non-gait analysis group.  In sub-analyses, patients in the gait analysis group had significantly more initial surgical procedures (5.8 vs. 4.2, p<0.01) than the group that did not have gait analysis.  Conversely, patients in the group not managed with gait analysis had more subsequent procedures (32% vs. 11%, p<0.001).  Study findings suggest that gait analysis does not significantly affect overall utilization and cost.  This study, however, did not specifically evaluate health outcomes.  Also, since the study was not randomized, there may have been uncontrolled baseline differences that affected the number of procedures received.

Several studies were identified in which children underwent both pre- and post-operative gait analysis.  In the study by Lofterod and colleagues, 60 children were referred for gait analysis after an initial surgical plan had been developed, based on clinical observation (Lofterod et al. 2007).  The original surgical plans were found to have been modified in 70% of patients following multidisciplinary team gait assessment.  In a follow-up report, patients were divided into three groups: Group A—Agreement between clinical evaluation, gait analysis, and subsequent surgery; Group B—Procedures were performed due to gait analysis recommendations that had not been part of initial surgical plan; Group C—Procedures that were part of the initial surgical plan were not performed because they were not recommended after gait analysis (Lofterod et al., 2008).  Based on gait analysis, surgery was not recommended in 11 children.  Fifty-five children, including 47 who received surgery, underwent follow-up gait analysis 1–2 years after the initial analysis.  Overall, at follow-up, there was improvement in kinematic parameters for children in Groups A and B.  This suggests that the change in treatment planning due to gait analysis may have been beneficial, or at least not harmful; we do not know what the outcome would have been if the original treatment plan had been followed.  Group C had fewer surgical procedures or no surgery; among children in this group, there were no statistically significant changes in any kinematic parameters at the follow-up gait analysis.  Of the eight children in Group C, four children had clinical deterioration during more than two years of follow-up and were recommended to have multilevel surgery; most of their kinematic parameters were in the normal range at the time of initial evaluation.  Based on this case series of patients referred for gait analysis, the authors concluded that gait analysis was useful for surgical planning.

Another study reviewed outcomes in 45 children who underwent gait analysis before and about a year after surgery that included collection of three-dimensional motion and force-plate data (Gough et al.).  The study aimed to determine whether gait analysis had a positive impact on treatment plans and whether gait analysis could predict which children would benefit from surgery.  Most children had about a year between gait analysis examinations.  Like the Lofterod study, patients were retrospectively classified into three groups, each with 15 children.  A key outcome measure was change in the Gillette Gait Index (GGI); the article states that a change of 10% in the index is clinically significant.  Based on change in the GGI, among the 15 children for whom surgery was not recommended, seven children improved, four were stable, and four deteriorated.  In the group that had surgery recommended, but not performed (due to family preference or other factors), six of 15 children improved, one was stable, and eight deteriorated.  In the group for whom surgery was recommended and performed, 12 children improved and three remained stable.  A limitation of this study is that the authors did not prospectively collect data on how treatment plans changed after the gait analysis; instead this was estimated by a multivariate analysis that found a significant association between the GGI and choice of treatment, which the authors state suggests that gait data influenced the treatment decision.  Limitations of both studies are their small sample sizes and the lack of a group of children who were managed without gait analysis.

A third study was published by Cimolin and colleagues in Italy in 2011.  It included 19 children with cerebral palsy scheduled for gastrocnemius fascial lengthening surgery and 20 healthy controls (for establishment of preoperative normative values).  Patient evaluation included videotaping and three-dimensional gait analysis.  The study used the Gait Deviation Index (GDI) to summarize data; this is a measure derived from comparing nine kinematic variables of a person’s gait to those of a control group.  A GDI value of approximately 100 or higher indicates an absence of gait pathology.  Every decrease in 10 points below 100 indicates 1 standard deviation (SD) from normal kinematics.  All participants completed the study.  The mean preoperative GDI value among the 19 children with cerebral palsy was 70.4 +/- 14.8 (i.e., 3 SDs away from healthy children).  After surgery, the mean GDI was 82.9 +/-7.4.  The improvement in GDI was statistically significant compared to the presurgery value (p<0.05).  The study did not evaluate whether there was incremental value with use of the postoperative GDI compared to postoperative observation alone.

Limitations of all three studies described above are their small sample sizes and the lack of a group of children with cerebral palsy who were managed without comprehensive gait analysis.

Pre- and/or Post-Surgical Evaluation for Other Conditions

In a study by Suda et al. (2002), gait analysis recommendations in 60 patients with neurogenic intermittent claudication were evaluated and compared to 50 healthy controls.  The authors concluded that gait analysis provided useful quantitative and objective information to evaluate post-surgical treatment.  However, the study does not address how the gait analysis influenced treatment decisions or affected health outcomes.

Sankar et al. received the records of 35 children (56 feet) who had recurrent deformity after treatment of idiopathic clubfoot.  Gait lab recommendations were compared to surgical plans prior to gait analysis, and to actual surgery received.  Thirty of 35 (86%) children underwent surgery.  Gait analysis resulted in changed procedures in 19 of 30 (63%) patients.  Gait analysis was found to influence clinical decisions but, like the study by Suda et al., this study does not evaluate whether these changes resulted in improved health outcomes.

Rehabilitation Planning and/or Evaluation

No relevant clinical studies were identified.

Ongoing clinical trials

Outcomes of orthopedic surgery using gait laboratory versus observational gait analysis in children with cerebral palsy (NCT00419432) (www.ClinicalTrials.gov).  

This is a double-blind randomized controlled trial evaluating whether the addition of gait analysis to routine observation improves surgical outcomes in ambulatory children with cerebral palsy.  Outcomes include measures of motor function and general functioning e.g., in the home and at school.  The investigators intend to enroll 50 children in the study, which is being conducted at sites in the U.S. and Canada.  The estimated date of study completion is October 2014.

Summary

Gait analysis is the quantitative assessment of coordinated muscle function.  No randomized controlled trials have been published that compare health outcomes in patients managed with and without gait analysis.  However, one nonrandomized study found that the overall number of surgical procedures and costs do not differ in patients with cerebral palsy who do or do not undergo gait analysis as part of surgical planning.  Several studies conducted among patients with cerebral palsy and other conditions suggest that gait analysis recommendations impact treatment decisions, but the impact of these decisions on health outcomes is as yet unknown.  Based on input from clinical reviewers, gait analysis, when comprehensive, may be medically necessary for planning prior to surgery in children with gait disorders associated with cerebral palsy.  Due to insufficient evidence, gait analysis is considered investigational for all other indications.

Coding

Disclaimer for coding information on Medical Policies           

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy.  They may not be all-inclusive.           

The presence or absence of procedure, service, supply, device or diagnosis codes in a Medical Policy document has no relevance for determination of benefit coverage for members or reimbursement for providers.  Only the written coverage position in a medical policy should be used for such determinations.           

Benefit coverage determinations based on written Medical Policy coverage positions must include review of the member’s benefit contract or Summary Plan Description (SPD) for defined coverage vs. non-coverage, benefit exclusions, and benefit limitations such as dollar or duration caps. 

ICD-9 Codes
93.09, 343.0-343.9 
ICD-10 Codes
G80.0 – G80.9, 4A0F33Z, 4A0FX3Z, F0101ZZ, F0111ZZ, F0121ZZ, F0131ZZ, F01D1ZZ, F01F1ZZ, F01G1ZZ, F01H1ZZ, F01J1ZZ, F01K1ZZ, F01L1ZZ, F01M1ZZ, F01ZDYZ, F01ZDZZ
Procedural Codes: 96000, 96001, 96002, 96003, 96004
References
  1. Gait analysis for pediatric cerebral palsy.  Chicago, Illinois: Blue Cross Blue Shield Association Technology Evaluation Center Assessment Program (2001).
  2. Suda, Y., Saitou, M., et al.  Gait analysis of patients with neurogenic intermittent claudication.  Spine (2002) 27(22):2509-13.
  3. Noonan, K.J., Halliday, S., et al.  Interobserver variability of gait analysis in patients with cerebral palsy.  Journal of Pediatric Orthopaedics (2003) 23(3):279-87.
  4. Lofterod, B., Terjesen, T., et al.  Preoperative gait analysis has a substantial effect on orthopedic decision making in children with cerebral palsy: comparison between clinical evaluation and gait analysis in 60 patients.  Acta Orthopaedica (2007) 78(1):74-80.
  5. Dobson F, Morris ME, Baker R et al.  Gait classification in children with cerebral palsy: A systematic review.  Gait Posture 2007; 25(1):140-52.
  6. Lofterod B, Terjesen T.  Results of treatment when orthopaedic surgeons follow gait-analysis recommendations in children with CP.  Dev Med Child Neurol 2008; 50(7):503-9.
  7. Gough M, Shortland AP.  Can clinical gait analysis guide the management of ambulant children with bilateral spastic cerebral palsy?  J Pediatr Orthop 2008; 28(8):879-83.
  8. Wren TA, Kalisvaart MM, Ghatan CE et al.  Effects of preoperative gait analysis on costs and amount of surgery.  J Pediatr Orthop 2009; 29(6):558-63.
  9. Sankar WN, Rethlefsen SA, Weiss J et al.  The recurrent clubfoot: can gait analysis help us make better preoperative decisions?  Clin Orthop Relat Res 2009; 467(5):1214-22.
  10. Outcomes of orthopedic surgery using gait laboratory versus observational gait analysis in children with cerebral palsy (NCT00419432).  Sponsored by the Hospital for Sick Children.  Last updated March 26, 2010.  Available at www.ClinicalTrials.gov (accessed 2011 December).
  11. Wren TA, Gorton GE, Ounpuu S et al.  Efficacy of clinical gait analysis: a systematic review.  Gait Posture 2011; 34(2):149-53.
  12. Cimolin V, Galli M, Vimercati SL et al.  Use of the Gait Deviation Index for the assessment of gastrocnemius fascia lengthening in children with cerebral palsy.  Res Dev Disabil 2011; 32(1): 377-81.
  13. Gait analysis.  Chicago, Illinois: Blue Cross Blue Shield Association Medical Policy Reference Manual (2012 February) Medicine 2.01.03.
History
September 2011  Policy references and rationale updated. Policy statement change and Medical necessity criteria added to allow as an aid in surgical planning in patients with gait disorders associated with cerebral palsy.
April 2012 Literature update for the period December 2010 through December 2011. Reference 4 added; other references renumbered or removed. Policy statements unchanged.
April 2013 Policy formatting and language revised.  Policy statement unchanged.
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Gait Analysis