MP 2.01.03 |
Gait Analysis |
|
| Medical Policy | ||
| Section Medicine |
Original Policy Date 12/1/95 |
Last Review Status/Date Reviewed with literature search/8:2007 |
| Issue 4:2007 |
Return to Medical Policy Index |
Disclaimer
Our medical policies are designed for informational purposes only and are not an authorization, or an explanation of benefits, or a contract. Receipt of benefits is subject to satisfaction of all terms and conditions of the coverage. Medical technology is constantly changing, and we reserve the right to review and update our policies periodically.
Description
Gait analysis, or motion 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 3 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 problemsrelated to aging, stroke, spinal cord injury, etc.
Policy
Gait analysis is considered investigational for all applications, including but not limited to evaluation of patients with cerebral palsy.
Policy Guidelines
Prior to 2002, no CPT codes explicitly described gait analysis, although CPT codes 95860-95870 describe various aspects of needle electromyography, some of which may have been used to describe components of gait analysis. In 2002, 5 new CPT codes were introduced that identify specific components of gait analysis as follows:
96000: Comprehensive computer-based motion analysis by videotaping and 3-D kinematics
96001: Above with dynamic plantar pressure measurements during walking
96002: Dynamic surface electromyography, during walking or other functional activities, 1–12 muscles
96003: Dynamic fine wire electromyography, during walking or other functional activities, 1 muscle
96004: Physician review and interpretation of comprehensive computer-based motion analysis, dynamic plantar pressure measurement, dynamic surface electromyography during walking or other functional activities, and dynamic fine wire electromyography, with written report.
Benefit Application
BlueCard/National Account Issues
Gait analysis has been most commonly performed in a research setting.
Rationale
This policy is based on a 2001 TEC Assessment (1) that 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.
While the 2001 TEC Assessment focused on the use of gait analysis in cerebral palsy, even less literature exists on gait analysis used in other musculoskeletal disorders.
Updates
Updated reviews of the peer-reviewed literature on MEDLINE revealed no clinical trial studies that would alter the conclusions reached above. In 1 study of 10 healthy individuals, Peters and colleagues evaluated the reproducibility of gait analysis using 1-step versus 3-step methods. (2) The authors concluded that both methods had comparable repeatability. However, each step analysis led to different results, demonstrating the need for further studies to identify standardized, reliable, and repeatable methods of data collection for gait analysis. In another study by Suda et al, gait analysis was compared in 60 patients with neurogenic intermittent claudication to 50 healthy controls. (3) The authors concluded that gait analysis provided useful quantitative and objective information to evaluate postsurgical treatment. However, the study does not address how the gait analysis influenced treatment decisions or effected health outcomes. In a retrospective study by Schwartz et al, data were reviewed on 135 children with spastic diplegia subtype of cerebral palsy from an existing database. (4) Children had undergone either orthopaedic surgery, selective dorsal rhizotomy, or both, and had pre- and postoperative gait analysis to assess functional outcomes. The authors concluded that preoperative gait analysis can be used to guide surgical intervention. However, how this would occur is unclear and, as the authors also note, this study design restricts interpretation of results. Therefore, the policy statement is unchanged.
2007 Update
A search of the MEDLINE database was performed from March 2006 through June 2007. One prospective study assessed the relation between blinded gait analysis data and clinical measurements in 200 randomly selected patients. (5) The study found only fair to moderate correlations between the measures (r 2 <= 0.60), none of the correlations were considered good. The authors suggested that gait analysis can provide different information than clinical measurement, but no data were presented to indicate that this additional information improved outcomes.
A prospective single-institution study evaluated the effect of gait analysis on surgical planning. (6) Preoperative surgical plans derived from clinical assessments were found to have been modified in 70% of patients following multi-disciplinary team gait assessment. Thirty-nine (65%) of the 60 patients had been referred by an orthopedic surgeon who was a member of the gait laboratory. A retrospective study of the influence of gait analysis recommendations reported that the surgeries performed matched those recommended in 23 (77%) of 30 consecutive patients who underwent orthopedic surgery at the author’s institution. (7) The gait laboratory physician was also the referring physician for nearly 65% of the 30 patients.
Although these studies indicate that gait analysis can influence clinical decision making, results cannot be generalized beyond these institutions. In a 2003 study funded by the United Cerebral Palsy Foundation, 4 different gait analysis centers gave different treatment recommendations after evaluating the same 11 patients. (8) Thus, there appears to be little consistency in gait analysis recommendations between centers. Questions remain, therefore, about both the reliability and the validity of gait analysis recommendations. Multicenter controlled studies are needed to determine whether gait analysis can improve clinical outcomes. The policy statement remains unchanged.
References:
- 2001 TEC Assessment: Gait analysis for pediatric cerebral palsy.
- Peters EJ, Urukalo A, Fleischli JG et al. Reproducibility of gait analysis variables: one-step versus three-step method of data acquisition. J Foot Ankle Surg 2002; 41(4):206-12.
- Suda Y, Saitou M, Shibasaki K et al. Gait analysis of patients with neurogenic intermittent claudication. Spine 2002; 27(22):2509-13.
- Schwartz MH, Viehweger E, Stout J et al. Comprehensive treatment of ambulatory children with cerebral palsy: an outcome assessment. J Pediatr Orthop 2004; 24(1):45-53.
- Desloovere K, Molenaers G, Feys H et al. Do dynamic and static clinical measurements correlate with gait analysis parameters in children with cerebral palsy? Gait Posture 2006; 24(3):302-13.
- Lofterod B, Terjesen T, Skaaret I 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 Orthop 2007; 78(1):74-80.
- Wren TA, Woolf K, Kay RM. How closely do surgeons follow gait analysis recommendations and why? J Pediatr Orthop B 2005; 14(3):202-5.
- Noonan KJ, Halliday S, Browne R et al. Interobserver variability of gait analysis in patients with cerebral palsy. J Pediatr Orthop 2003; 23(3):279-87
|
Codes |
Number |
Description |
| CPT | See Policy Guidelines | |
| ICD-9 Procedure | 93.09 | Other diagnostic physical therapy procedures |
| ICD-9 Diagnosis | Investigational for all codes | |
| HCPCS | No Code | |
| Type of Service | Medical/Diagnostic | |
| Place of Service | Inpatient Outpatient |
|
Index
Dynamic EMG
Electrodynagram™
Gait Analysis
Motion Analysis
Surface EMG
Policy History
| Date | Action | Reason |
| 12/01/95 | Add to Medicine section | New policy |
| 07/31/97 | Replace policy | Reviewed with changes; description clarified |
| 02/15/02 | Replace policy | Policy updated with TEC Assessment; no change in policy statement |
| 02/25/04 | Replace policy | Literature review update for the period of 2002 through 2003; policy statement unchanged |
| 04/1/05 | Replace policy | Literature review update for the period of 2004 through February 2005; policy statement unchanged |
| 3/7/06 | Replace policy | Literature review update for the period of 2005 through February 2006; policy statement unchanged |
| 08/02/07 | Replace policy | Literature review update for the period of 2006 through June 2007; reference numbers 5-8 added; policy statement unchanged. |
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