Medicine Section - Gait Analysis

IMPORTANT REMINDER

Regence Medical Policies are developed to provide guidance for members and providers regarding coverage in accordance with contract terms. Benefit determinations are based in all cases on the applicable contract language. To the extent there may be any conflict between the Medical Policy and contract language, the contract language takes precedence.

PLEASE NOTE: Contracts exclude from coverage, among other things, services or procedures that are considered investigational or cosmetic. Providers may bill members for services or procedures that are considered investigational or cosmetic. Providers are encouraged to inform members before rendering such services that the members are likely to be financially responsible for the cost of these services.

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 videotaped observation of patient walking. Videos can be observed from several visual planes at slow speed, revealing movements not detectable at normal speed. Joint angles 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 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, and for planning for rehabilitative strategies for a variety of disorders.

Policy/Criteria

Gait analysis may be considered medically necessary in children and adolescents with cerebral palsy to select surgical or other therapeutic interventions for gait improvement. All other indications for gait analysis are considered investigational.

Scientific Background

This policy is based, in part, on a 2001 BlueCross BlueShield Association Technology Evaluation Center (TEC) Assessment summarized below. (2)

Up to the time that a walking pattern has developed, physical therapy is considered the mainstay of treatment in children with cerebral palsy. The ideal age range for orthopedic interventions is between the ages of 4 to 6 years. The current trend in treatment is to perform all procedures at one time, rather than in stages. Modern gait analysis techniques are considered an important tool by some practitioners in order to evaluate all aspects of a patient's gait at one time, thus allowing simultaneous treatment of as many abnormalities as possible.

Surgical procedures consist of a variety of procedures, many which involve lengthening various muscles and tendons from the hip to the foot, depending on the abnormality. Additional treatments that control spasticity are dorsal rhizotomy and botulinum toxin injections. Dorsal rhizotomy is a surgical procedure that selectively severs nerve roots at the spinal column. Botulinum toxin is a neuromuscular blocker which blocks nerve conduction to the muscle.

Modern gait analysis techniques have the potential to provide accurate, reliable, and quantifiable data on specific aspects of gait, but they have their limitations and demands. The data are very complex and users must be well trained and cognizant of the many potential sources of error. The potential benefits of gait analysis are improved treatment decision making, so that surgery and other treatments result in improved walking capability.

DeLuca and colleagues studied 91 patients with both clinical assessment and gait analysis. (3) The same physicians made a recommendation on surgical treatment based on clinical assessment, and then another recommendation after gait analysis data were reviewed. Changes were made in 47 (52%) patients. More surgery was recommended in 21, less surgery was recommended in 24, and the same number of surgeries but different procedures in two.

In a retrospective study by Schwartz and colleagues, data was reviewed on 135 children with spastic diplegia subtype of cerebral palsy from an existing database. (4) Children had undergone either orthopedic surgery, selective dorsal rhizotomy, or both and had pre and post-operative 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.

Wren and colleagues retrospectively reviewed 30 consecutive children who underwent surgery following gait analysis. (5) The purpose of this study was to determine the rate and reasons for discrepancies between the surgeries recommended based on gait analysis data and the surgeries actually performed.  The gait laboratory recommendations were followed exactly in 23 (77%) of the surgeries.  However, the authors noted that the gait laboratory physician was the referring physician for 19 of the 30 patients, introducing possible bias. When that physician’s patients were excluded from the analysis the rate of surgeries performed which match the gait laboratory recommendations fell to 55%.  The authors conclude that many surgeons use gait analysis data as one source of information when planning surgical procedures, but caution that, since this study was a single-center study and included a majority of subjects operated on by the gait laboratory physician, it is not clear to what extent these findings can be generalized.

Kay and colleagues studied the effect of postoperative gait analysis on recommendations in patient care in 41 patients, most with cerebral palsy.  (6) Postoperative gait analysis was part of the routine protocol after surgery for these patients. Changes in treatment were recommended in 32 (84%) of patients based on the results of the gait study. Recommendations for treatment changes included recommendations for surgery in 16 (42%) patients, bracing changes in 20 (53%) patients, and physical therapy changes in 8 (21%) patients. However, since the study is retrospective and there is no control group, it cannot be concluded that the change in care would not have been recommended anyway and that the gait analysis served merely to confirm the physicians’ clinical judgment about an appropriate change in care.

Hailey and Tomie published a review of the body of evidence concerning gait analysis in children with cerebral palsy and spina bifida. (7) Based on the available evidence the authors concluded that gait analysis seems helpful in detecting gait changes. However, available evidence is insufficient to draw conclusions about the influence of computerized gait analysis on treatment outcomes. The authors state that gait analysis should be regarded as a developing technology and its clinical application should be linked to systematic collection and assessment of outcomes data.

While the 2001 TEC Assessment focused on the use of gait analysis in cerebral palsy, even less literature exists on gait analysis used in the management of other musculoskeletal disorders.

In one study of 10 healthy individuals, Peters and colleagues evaluated the reproducibility of gait analysis using one-step versus three-step methods. (8) The authors concluded that both methods had comparable repeatability. However, each step analysis led to different results and demonstrates the need for further studies to identify standardized, reliable, and repeatable methods of data collection for gait analysis. In another study by Suda and colleagues, gait analysis was compared in 60 patients with neurogenic intermittent claudication to 50 healthy controls.  (9)  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 effected health outcomes. In publications addressing gait analysis for other indications, there was a similar inability to reach conclusions concerning the impact of gait analysis on health outcomes due to the small, uncontrolled nature of the studies. (10-12)  An updated search of the MEDLINE database through May 22, 2008 identified no clinical trials that alter the conclusions reached above.

References

1. BlueCross BlueShield Association Medical Policy Reference Manual, Policy No. 2.01.03
2. TEC Assessment: Gait Analysis for Pediatric Cerebral Palsy, 2001; BlueCross BlueShield Association Technology Evaluation Center. Vol. 16, Tab 19
3. DeLuca PA, Davis RB, et al. Alterations in surgical decision making in patients with cerebral palsy based on three-dimensional gait anlysis. J Pediatr Orthop 1997;17(5):608-14
4. 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
5. 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
6. Kay RM, Dennis S, Rethlefsen S et al. Impact of postoperative gait analysis on orthopaedic care. Clin Orthop 2000(374):259-64
7. Hailey D, Tomie J. An assessment of gait analysis in the rehabilitation of children with walking difficulties. Disabil Rehabil 2000;22(6):275-80
8. Peters EJ, Urkalo A, Fleischi JG, Lavery LA. Reproducibility of gait analysis variables: one-step versus three-step method of data acquisition. J Foot Ankle Surg 2002;41(4):206-12
9. Suda Y, Saitou M, Shibasaki K et al. Gait analysis of patients with neurogenic intermittent claudication. Spine 2002;27(22):2509-13
10. Verghese J, Lipton RB, Hall CB, et al. Abnormality of gait as a predictor of non-Alzheimer's dementia. N Engl J Med. 2002;347(22):1761-8
11. Fairburn PS, Panagamuwa B, Falkonakis A, et al. The use of multidisciplinary assessment and scientific measurement in advanced juvenile idiopathic arthritis can categorize gait deviations to guide treatment. Arch Dis Child. 2002;87(2):160-5
12. Fuller DA, Keenan MA, Esquenazi A, et al. The impact of instrumented gait analysis on surgical planning: treatment of spastic equinovarus deformity of the foot and ankle. Foot Ankle Int. 2002;23(8):738-43

Cross References

None

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