Abstract
Background Biofeedback has been used in rehabilitation settings for gait retraining.
Purpose The purpose of this review was to summarize and synthesize the findings of studies involving real-time kinematic, temporospatial, and kinetic biofeedback. The goal was to provide a general overview of the effectiveness of these forms of biofeedback in treating gait abnormalities.
Data Sources Articles were identified through searches of the following databases: MEDLINE, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Cochrane Central Register for Controlled Trials. All searches were limited to the English language and encompassed the period from 1965 to November 2007.
Study Selection Titles and abstracts were screened to identify studies that met the following requirements: the study included the use of kinematic, temporospatial, or kinetic biofeedback during gait training, and the population of interest showed abnormal movement patterns as a result of a pathology or injury.
Data Extraction All articles that met the inclusion criteria were assessed by use of the Methodological Index for Nonrandomized Studies.
Data Synthesis Seven articles met the inclusion criteria and were included in the review. Effect sizes were calculated for the primary outcome variables for all studies that provided enough data. Effect sizes generally suggested moderate to large treatment effects for all methods of biofeedback during practice.
Limitations Several of the studies lacked adequate randomization; therefore, readers should exercise caution when interpreting authors’ conclusions.
Conclusions Each biofeedback method appeared to result in moderate to large treatment effects immediately after treatment. However, it is unknown whether the effects were maintained. Future studies should ensure adequate randomization of participants and implementation of motor learning concepts and should include retention testing to assess the long-term success of biofeedback and outcome measures capable of demonstrating coordinative changes in gait and improvement in function.
Biofeedback was first introduced in the literature more than 30 years ago as a training tool used in rehabilitation settings to facilitate normal movement patterns after injury.1 Since then, biofeedback has been used primarily in rehabilitation settings for the treatment of gait abnormalities in adults after stroke.2–12 Biofeedback also has been used to facilitate the normalization of gait patterns in children with cerebral palsy13 and in adults after amputation,14 after spinal cord injuries,15 after hip fractures,14 and after total hip14,16 and knee14 joint replacements.
Biofeedback is a technique that typically uses electronic equipment to provide a client with auditory signals, visual signals, or both regarding internal physiological events, both normal and abnormal (eg, heart rate, blood pressure, and level of muscle activity).17 During biofeedback for gait retraining, the client is provided with augmented information (eg, kinematics, kinetics, and electromyography) regarding physiological responses. Additionally, biofeedback provides clinicians with a useful tool for giving clients instructions on how to modify movement patterns. Thus, biofeedback complements the already present internal feedback (ie, visual, auditory, and proprioceptive feedback) and acts as a “sixth sense.”18 Biofeedback typically is provided instantaneously to the learner (ie, in real time), whereas other methods of external feedback (eg, verbal and video feedback) are provided some time after the movement. More recently, a resurgence of interest in real-time feedback has developed because of the expansion of technology related to kinematic19 and kinetic14,16 biofeedback.
Electromyographic biofeedback may be the most popular method of providing biofeedback and has been used frequently in gait retraining after stroke. However, meta-analyses of electromyographic biofeedback studies of people after stroke have concluded that little evidence supports its use in addition to conventional physical therapy.20,21 Other forms of biofeedback, such as kinematic,2,8,9 temporospatial,6,7 and kinetic,14,16 also have been developed and used in rehabilitation settings for gait retraining. It remains unknown whether these methods are effective in treating gait abnormalities. Therefore, the purpose of this systematic review was to summarize and synthesize the findings of studies involving real-time kinematic, temporospatial, and kinetic biofeedback. This effort provided a general overview of the effectiveness of these forms of biofeedback in treating gait abnormalities.
Method
Data Sources and Searches
Three electronic databases were searched in a systematic fashion to identify relevant articles: MEDLINE, CINAHL (Cumulative Index to Nursing and Allied Health Literature), and Cochrane Central Register for Controlled Trials. All searches were limited to the English language and encompassed the period from 1965 to November 2007. The following key words were used in the searches: feedback, biofeedback, walking, ambulation, and gait. Key words were combined to identify studies involving biofeedback and gait. Table 1 shows the specific key words and combinations of key words used in each search. Each review article that was identified by MEDLINE also was manually searched to identify other potential articles.
Study Selection
One reviewer (J.J.T.) screened titles and abstracts identified during electronic and manual searches to determine eligibility. In the event that the title or abstract did not provide enough information, the article was obtained for full review. Published articles were considered for initial inclusion in the review if the following requirements were met: the study included the use of kinematic, temporospatial, or kinetic biofeedback during gait training and the population of interest showed abnormal movement patterns as a result of a pathology or injury. Figure 1 shows a flow diagram of the systematic review process.
Flow diagram of the systematic review process.
Data Extraction and Quality Assessment
All articles that met the inclusion criteria were assessed by 2 reviewers (J.J.T. and C.E.M.) using the Methodological Index for Nonrandomized Studies (MINORS).22 The MINORS instrument has been determined to be valid and reliable in assessing the methodological quality of both randomized and nonrandomized studies.22 Scores on the MINORS range from 0 to 24 for randomized studies and 0 to 16 for nonrandomized studies. The following methodological items are assessed with the MINORS instrument: aim of the study, inclusion of consecutive participants, prospective data collection, appropriate outcome assessments, unbiased assessments of outcomes, appropriate follow-up, attrition, and sample size. In addition, the quality of the comparison group and statistical analyses in randomized trials only are assessed.
Furthermore, the 2 reviewers clarified the intent of the questions concerning the inclusion of consecutive participants and prospective data collection to improve interrater reliability. The purpose of the question concerning the inclusion of consecutive participants was to judge whether inclusion and exclusion criteria were included in the study. The purpose of the question regarding prospective data collection was to judge whether the study was descriptive (score of 0) or prospective (score of 1 or 2). The delineation between scores of 1 and 2 for prospective quality was based on whether the study demonstrated 1 or more specific a priori aims and hypotheses.
The MINORS scores were averaged across the 2 reviewers to enable the ranking of studies. A histogram of the studies and their MINORS scores was created to assist in determining a cutoff point, based on the natural clustering of groups, for inclusion in the review (Fig. 2).
Histogram of scores on the Methodological Index for Nonrandomized Studies.22
Data Synthesis and Analysis
A meta-analysis was not performed because of the wide variety of study designs, methodologies, and outcome variables. Effect sizes (ESs) were calculated for the primary outcome variables for all studies that provided enough data. Effect sizes were calculated by subtracting the mean score at the baseline from the mean score after treatment and then dividing the result by a standard deviation resulting from pooling of the baseline and treatment standard deviations.23 Effect sizes were used in this review to provide a means of evaluating treatment success because they are not directly affected by sample size but take into account within-group variability. Effect sizes were standardized on the basis of the work of Cohen (small=.02, moderate=0.5, and large=0.8).23 All ESs represented comparisons of the mean posttreatment and follow-up (if applicable) scores with the mean baseline scores for each of the biofeedback and control groups. The ES for change over time in the biofeedback group was then compared with that in the control group. Percent differences also were calculated to aid in the interpretation of studies that did not provide enough data to calculate ESs.
Results
Study Identification
A search of the MEDLINE database identified a total of 504 articles, a search of the CINAHL database identified 162 articles, and a search of the Cochrane Central Register of Controlled Trials identified 85 articles. In total, 666 individual articles were identified by these databases. Fifty-eight of these articles were identified as potentially relevant, and their full texts were retrieved. After an initial review by the first reviewer (J.J.T.), 35 of these articles were excluded because they did not meet the inclusion criteria. Both reviewers assessed the remaining 23 studies using the MINORS instrument. Of the 23 articles assessed, 7 achieved a score of 16 or greater out of a possible 24 and were included in the review (Fig. 1). A cutoff point of 16 was identified qualitatively on observation of the histogram as a natural breakpoint between clusters of studies (Fig. 2). Tables 2, 3, and 4 summarize the characteristics of the included studies with regard to participant population, sample sizes, participant ages, treatment protocols, presence of masking and retention tests, quantitative variables, functional outcome measures, and conclusions drawn by the authors.
Biofeedback Protocol
Generally, there was a large range in the structures of the treatment protocols. The mean treatment time in all studies was 35 minutes, with a range of 15 to 50 minutes, and the mean treatment frequency was 4 times per week, with a range of twice per week to daily treatments. The mean treatment duration was 3.5 weeks, with a range of 1.5 to 8 weeks. The mean cumulative biofeedback time per study (ie, treatment time × treatment frequency × treatment duration) was 397 minutes, with a range of 120 to 900 minutes.
Kinematic Biofeedback
In 3 studies, kinematic biofeedback was provided with electrogoniometers (Tab. 2). All 3 studies involved analysis of the effect of kinematic biofeedback in participants who had had a stroke. Ceceli et al8 and Morris et al9 analyzed the effectiveness of providing participants (n=41 and 26, respectively) with kinematic biofeedback of the knee compared with conventional physical therapy in efforts to minimize genu recurvatum. Colborne et al2 investigated the effectiveness of providing participants (n=8) with kinematic biofeedback for the ankle in attempts to improve ankle control. Outcome measures included gait speed,2,8,9 number of recurvations,8 and symmetry.2,9
Ceceli et al8 assigned participants to either an experimental group (n=26) or a control group (n=15). Both groups received conventional therapy that consisted of pelvis and hip control exercises, weight shifting, and gait training. In addition, participants in the experimental group received kinematic biofeedback for 10 daily sessions, each lasting 30 minutes. Posttreatment data were collected for participants in the experimental group at the end of the 10 days of biofeedback training; data were collected for participants in the control group at the time of discharge.
In the study by Morris et al,9 participants received treatment in 2 separate phases, lasting 4 weeks each. Participants in the experimental group (n=13) received kinematic biofeedback during the first phase and conventional physical therapy during the second phase. Kinematic biofeedback of the involved knee was provided to participants during standing and gait training for 30 to 45 minutes per treatment session. Participants in the control group (n=13) received conventional physical therapy during both phases. Outcome data were collected for all participants at baseline and after each treatment phase.
Colborne et al2 used a 3-period crossover design to assess the effectiveness of kinematic biofeedback. The 8 participants received 1 of 3 treatments: kinematic biofeedback, electromyographic biofeedback, and conventional physical therapy. Conventional physical therapy was given during either the first phase (n=4) or the last phase (n=4). Each treatment phase lasted 4 weeks and consisted of biweekly treatment sessions, each lasting 30 minutes. No washout periods were included between treatments. Gait speed data were collected for all participants at baseline, after each treatment phase, and at a 1-month follow-up.
Ceceli et al8 found that participants in the experimental group showed a statistically significant decrease in the number of recurvations compared with the control group immediately after treatment—from 45 to 8 recurvations, an 83% decrease, for the experimental group, and from 49 to 39 recurvations, a 19% decrease, for the control group. Additionally, participants were asked to return for a 6-month follow-up. However, we did not calculate ESs or percent differences for 6-month follow-up data because of the poor participant follow-up rate (<50%); with a low follow-up rate, the data might not be a good representation of the data for all participants.
Morris et al9 reported a moderate effect for increased gait speed in the experimental group (increase of 0.10 m/s, ES=0.50, 33% increase) but no effect in the control group (increase of 0.01 m/s, ES=0.08, 5% increase) after the first treatment phase. Both groups had similar baseline gait velocities (0.33 m/s in the experimental group and 0.30 m/s in the control group). Both groups showed statistically significant reductions in peak knee extension during stance, although no group difference was noted. After the second treatment phase, a large increase in gait speed was reported in the experimental group (increase of 0.23 m/s, ES=1.45, 75% increase), but only a small change was reported in the control group (increase of 0.10 m/s, ES=0.46, 37% increase). Additionally, participants in the experimental group showed a statistically significant decrease in peak knee extension compared with participants in the control group. Effect sizes and percent differences for peak knee extension could not be calculated because of a lack of data.
Colborne et al2 found that kinematic biofeedback training resulted in a moderate increase in gait speed (increase of 0.11 m/s, ES=0.51, 23% increase) but that conventional therapy resulted in only a small improvement (increase of 0.08 m/s, ES=0.37, 17% increase). Participants in both of those treatment groups had the same baseline gait speed (0.48 m/s). We did not interpret the follow-up data because carryover effects for either or both treatment methods might have occurred as a result of the crossover design of the study.24
Temporospatial Biofeedback
In 2 studies, temporospatial biofeedback was provided for participants after stroke (Tab. 3). Aruin et al6 investigated the effectiveness of biofeedback regarding the base of support in 16 participants, and Montoya et al7 analyzed the effectiveness of biofeedback regarding step length in 14 participants. Biofeedback was provided in efforts to improve the base of support6 and the symmetry of step length.7 Outcome measures included step width6 and step length.7
Aruin et al6 randomly placed participants in either an experimental group (n=8) or a control group (n=8). Both groups received conventional physical therapy twice daily for 25 minutes for 10 days. Conventional physical therapy consisted of weight shifting, trunk stabilization, lower-extremity muscle facilitation, and gait training. Participants in the experimental group received biofeedback on their base of support through sensors placed around the proximal leg. These sensors provided participants with an auditory signal when their base of support was below an established threshold. Data on the base of support were collected for all participants at baseline and 10 days after the start of treatment.
Montoya et al7 placed participants in either an experimental group (n=9) or a control group (n=5). Participants in the experimental group received biofeedback 2 times per week for 4 weeks for a total of 8 sessions. Participants in the control group practiced walking at the same dosage but without biofeedback. Both groups also participated in a standardized rehabilitation program while enrolled in the study. Step-length biofeedback, with visual and auditory signals provided from a lighted walkway, was provided to participants in the experimental group. Step-length data were collected for all participants at baseline and at the beginning and the end of each treatment session (n=8).
Aruin et al6 reported large improvements in step width in both the experimental group and the control group. However, the experimental group showed a larger improvement in step width (increase of 0.07 m, ES=12.7, 78% increase) than the control group (increase of 0.03 m, ES=8.57, 30% increase). Both groups had similar baseline step widths (0.09 m in the experimental group and 0.10 m in the control group). Effect sizes for both groups were quite large because of very small reported standard deviations.
Montoya et al7 also reported large improvements in step length in both the experimental group and the control group. Likewise, the experimental group showed a larger improvement in step length (increase of 0.26 m, ES=11.1, 79% increase) than the control group (increase of 0.12 m, ES=2.49, 43% increase). Both groups had similar baseline step lengths (0.34 m in the experimental group and 0.28 m in the control group). Again, ESs for both groups were quite large because of small reported standard deviations. Neither study included a follow-up assessment.
Kinetic Biofeedback
Participants were provided with kinetic biofeedback in 2 studies (Tab. 4). Isakov14 investigated the effectiveness of kinetic biofeedback in a disparate group of participants (n=42) who had undergone a total hip or knee replacement or a recent amputation or had had a femoral neck fracture. White and Lifeso16 analyzed the effectiveness of kinetic biofeedback in participants (n=28) after a total hip replacement. Biofeedback was provided either to increase the overall amount of weight placed on an involved lower extremity14 or to promote kinetic symmetry between limbs.16 Outcome measures included changes in weight bearing14 and symmetry for the peak force during the loading phase, loading rate, and vertical impulse.16 White and Lifeso16 also included a functional outcome measure, the Harris Hip Score.25
Isakov14 randomly assigned participants to an experimental group (n=24) or a control group (n=18). Participants in the experimental group received biofeedback for 30 minutes in 4 physical therapy sessions during a 2-week period. Participants in the control group received conventional gait therapy to promote full weight bearing. Participants were given kinetic biofeedback through an in-shoe device that provided auditory feedback to promote an increase in weight bearing during gait training. Kinetic data were collected for all participants at baseline and immediately after treatment.
White and Lifeso16 assigned participants to 1 of 3 groups: a biofeedback group (n=12), a no-biofeedback comparison group (n=8), and a no-treatment control group (n=8). Participants in the biofeedback and no-biofeedback comparison groups trained on a treadmill 3 times per week for 8 weeks for a total of 24 sessions. Participants were given kinetic biofeedback through a monitor that provided real-time visual displays of bar graphs representing the peak force during the first half of stance (ie, the loading response). In addition, participants receiving biofeedback were given verbal cues aimed at improving kinetic symmetry. Outcome data were collected for all participants at baseline and after treatment.
Isakov14 reported a statistically significant difference between the experimental group and the control group in improvements in weight bearing during gait. The average increase in weight bearing in participants in the experimental group was 7.9 kg, but participants in the control group did not show a meaningful change (increase of 0.7 kg). Effect sizes and percent differences could not be calculated because of a lack of critical variables.
White and Lifeso16 reported that participants in the biofeedback group showed significant improvements in symmetry for the loading rate (decrease of 15%, ES=4.0, 62% improvement in symmetry) and vertical impulse (decrease of 6.1%, ES=4.7, 80% improvement in symmetry). Participants in the no-biofeedback comparison group also showed an improvement in loading rate symmetry (decrease of 9.1%, ES=1.46, 35% improvement in symmetry) but showed no change in peak force or vertical impulse. No changes in symmetry indices for any of the outcome measures were noted for participants in the no-treatment control group. Neither study included a follow-up assessment.
Discussion
The specific aim of this review was to summarize and synthesize the findings of studies involving real-time kinematic, temporospatial, and kinetic biofeedback. The goal was to provide a general overview of the effectiveness of these forms of biofeedback in treating gait abnormalities. Effect sizes and percent differences suggested that kinematic, temporospatial, and kinetic biofeedback resulted in moderate to large short-term treatment effects, indicating greater success for biofeedback than for conventional therapy. Kinematic and temporospatial biofeedback training interventions were used for participants after stroke, whereas kinetic biofeedback was used for participants who had undergone a total hip or knee replacement or an amputation or had had a recent hip fracture.
This review highlights the need for further research on real-time biofeedback to determine whether kinematic, temporospatial, or kinetic biofeedback or a combination of these techniques results in motor learning. Only 3 of the 7 studies included a long-term follow-up assessment.2,8,9 Morris et al9 reported that treatment effects were even larger at a 4-week follow-up assessment than they were immediately after treatment. They believed that this result might have been due to participants who received biofeedback having difficulty transferring gait changes from the feedback condition to the testing condition (no feedback). Morris et al9 further suggested that lower performance at the assessment immediately after treatment than at the 4-week follow-up assessment might have been due to participants becoming dependent on receiving biofeedback in order to alter gait effectively. The control group did not experience this effect because the testing condition was similar to the training condition. It was first suggested by Salmoni et al26 that concurrent feedback could impede motor learning by preventing the processing of other sensory information. The follow-up assessment by Colborne et al2 was limited by the crossover design of the study, which made it difficult to separate the individual effects of the treatments. Likewise, the follow-up assessment by Ceceli et al8 was limited because of a poor response rate (<50%), which limited the demonstration of any potential learning effects.
Therefore, the long-term successes of kinematic, temporospatial, and kinetic biofeedback methods are unclear at present. The results of Morris et al9 might indicate that positive changes can be maintained, at least for a few weeks. However, it is impossible to generalize about whether motor learning truly occurred in the balance of the studies reviewed because of a lack of retention testing across the studies. Because the purpose of biofeedback is to promote the learning of a meaningful and permanent change in gait, such follow-up testing should be included in future research.
The treatment protocols for each method varied in terms of treatment time per session, treatment frequency (ie, sessions per week), and treatment duration (ie, total number of weeks). Some investigators chose a shorter treatment time per session (ie, 15–30 minutes) and a lower treatment frequency (ie, 2 or 3 sessions per week),2,14,16 whereas another study with a similar treatment time per session had daily treatment.8 Moreover, some studies with a longer treatment time per session (ie, 45–50 minutes) had a variety of treatment frequencies, ranging from as little as 2 times per week to daily treatment.6,7,9 In several studies, biofeedback treatment was combined with standard physical therapy, so that the actual duration of the biofeedback treatment was not specifically reported. Therefore, we are unable to suggest an optimal biofeedback treatment protocol on the basis of the body of literature included in this review. Future studies should incorporate treatment protocols founded on sound physiological principles and reflecting common scheduling practices currently used in health care.
Limitations of Existing Studies
Randomized controlled designs are regarded as the gold standard in terms of providing the best evidence about the effectiveness of a particular treatment. The majority of the studies included in this review had control groups.6–9,14,16 Despite the presence of a control group, the results of a few studies should be interpreted with caution. The study by White and Lifeso16 had inadequate randomization. In that study, differences in age among the no-treatment control group (60 years), the no-biofeedback comparison group (70 years), and the biofeedback group (51 years) could have resulted in age being a confounding factor. Furthermore, the biofeedback and no-feedback comparison groups differed from the control group in terms of baseline function as defined by the Harris Hip Score.25 Isakov14 provided data only for pretest and posttest changes and did not provide the exact baseline and posttreatment data. Therefore, we could not determine whether the treatment and control groups had similar baseline values for the outcome variables. Potential baseline differences might be confounding factors affecting the outcome of retraining studies and could lead to misleading conclusions about the effects of biofeedback. Colborne et al2 used a crossover design, in which participants acted as their own control and received both biofeedback and conventional therapy during the study. This study design might have limited the ability to fully separate the treatment effects of biofeedback and conventional therapy and might also have made it difficult to identify which treatment was the source of any permanent changes (ie, motor learning). Interactive or additive effects of physical therapy, biofeedback, and time might have occurred.
None of the studies explicitly included motor learning concepts in the study design. Winstein et al27 reported that concurrent feedback led to good performance on a partial–weight-bearing task during the acquisition phase. However, the removal of this guidance led to a degradation of performance during retention testing. This phenomenon is well known in the motor learning literature. In particular, Swinnen28 suggested that researchers regularly expose learners to nonaugmented conditions to avoid dependence on augmented feedback. White and Lifeso16 were the only investigators to expose participants to nonaugmented conditions. In that study, participants receiving biofeedback walked in 5-minute blocks for a total of 15 minutes. During each block, participants walked for 3 minutes with feedback and for 2 minutes without feedback. Motor learning principles suggest that this type of design would be a key component of a successful program. Janelle et al29 tested a novel method of presenting augmented feedback to participants by allowing them to self-control feedback scheduling. The results of that study indicated that participants in the self-control group performed better on retention tests than participants who received different forms of scheduled or random feedback. They suggested that self-controlled feedback provides an environment in which participants play a more active role in their learning, thus resulting in improved motor performance and motor learning.
The majority of the studies included only immediate retention testing after biofeedback intervention. Therefore, their results were limited to providing evidence of short-term changes in motor performance. It is possible that temporary practice effects associated with biofeedback training had yet to subside and thus influenced the results. The inclusion of longer-term retention intervals (eg, 6-months or 1 year) in biofeedback study designs is essential to determining whether motor learning has occurred as a result of the biofeedback.
In all of the studies assessing gait changes after kinematic biofeedback in participants after stroke, gait speed was used as the primary outcome measure. Schmid et al30 reported that significant gains in gait speed were associated with meaningful improvements in function and quality of life. However, gait speed alone does not reveal changes in coordination in walking or reflect motor learning. Gait outcome measures such as the Tinetti Performance-Oriented Mobility Assessment31 and the Gait Assessment Rating Scale32 can provide some additional information regarding changes in movement patterns on the basis of a clinical evaluation. Recent advances in technology also have made it possible for researchers and clinicians to collect temporospatial values more easily by using tools such as the GAITRite System* or the GaitMat II.† A 3-dimensional analysis also can provide researchers and clinicians with a detailed kinematic and kinetic gait analysis. However, this type of analysis requires more expensive equipment and advanced training. Two of the 7 studies included functional outcome measures to assess improvements in function related to gait retraining.9,16 In the study by Morris et al,9 participants were assessed after stroke with the Motor Assessment Scale,33 and White and Lifeso16 assessed participants after total hip replacement by using the Harris Hip Score.25 Functional outcome measures specific to a participant population may be helpful in indicating quality of life and thus positive changes in function associated with biofeedback training.
Limitations of This Systematic Review
The results of this systematic review are limited to studies that were written in the English language and included in the MEDLINE, CINAHL, and Cochrane databases or the reference lists of review articles identified in those databases. Other studies may exist outside these resources. Selection bias is another potential limitation of systematic reviews. However, we attempted to minimize this limitation by using the MINORS instrument, which was designed to assess the methodological quality of both randomized and nonrandomized studies. Although nonrandomized studies were not included in this review, we did not make a specific methodological decision to exclude them; they were indirectly excluded as a result of their low MINORS scores. Publication bias is another potential limitation of any type of literature review. Frequently, only studies demonstrating positive results are submitted to peer-reviewed journals and published. This situation may bias results toward positive treatment effects. However, this limitation is impossible to quantify.
Clinical Implications
On the basis of the current literature, there are insufficient data to make a recommendation in the form of a clinical practice guideline. Despite this shortcoming, we recommend that clinicians using real-time biofeedback select outcome measures capable of revealing changes in coordination during walking. Additionally, clinicians should consider incorporating motor learning principles into their treatment protocols to provide clients with a practice environment that promotes motor learning. Clinicians should consider using faded feedback schedules along with random and variable practice to promote improved performance during retention testing.34 Clinicians should also consider informing clients about the potential negative aspect of concurrent feedback to minimize its impact on learning.28
Future Directions
Few studies have investigated the effectiveness of real-time kinematic, temporospatial, and kinetic biofeedback. Despite the small number of studies, this systematic review indicated that these methods of biofeedback were capable of providing moderate to large short-term treatment effects. Therefore, future research is warranted to provide clarity regarding the potential long-term benefits of real-time biofeedback for gait retraining.
On the basis of the results of this systematic review, several recommendations for future research can be made. Future work should include adequate randomization to ensure that both experimental and control groups are equivalent at baseline, before biofeedback intervention. Researchers should incorporate existing motor learning concepts into study designs to minimize the negative effects of real-time feedback while maximizing the benefits. Future studies also should include multiday retention testing (eg, at 6 months or 1 year) to assess the learning of gait changes. Evidence of permanent changes (ie, motor learning) is urgently needed to support the continued use of biofeedback in rehabilitation settings. To obtain such evidence, researchers should include outcome measures that provide more information about coordination during gait and overall walking function.
Conclusions
Real-time kinematic, temporospatial, and kinetic biofeedback appears to result in short-term moderate to large treatment effects. However, it is unknown whether treatment changes are maintained. Several studies lacked adequate randomization, a fact that should caution readers when interpreting the authors’ conclusions. Future studies should ensure adequate randomization of participants as well as the implementation of motor learning concepts and the inclusion of retention testing to assess the long-term success of biofeedback. They also should include outcome measures capable of demonstrating coordinative changes in gait and improvements in function.
The Bottom Line
What do we already know about this topic?
Over the past 30 years, many different types of real-time biofeedback have been used by both researchers and clinicians in the treatment of gait abnormalities in different patient groups.
What new information does this study offer?
This systematic review of published studies involving real-time kinematic, temporospatial, or kinetic biofeedback found consistent evidence of short-term improvements in gait. However, no conclusive evidence was found regarding the long-term effects of real-time biofeedback.
If you’re a patient, what might these findings mean for you?
Some patients with specific gait abnormalities may benefit from the use of real-time biofeedback. However, patients should keep in mind that it is still unknown whether the short-term changes are retained in the longer term.
Footnotes
- Received September 10, 2008.
- Accepted April 27, 2010.
- © 2010 American Physical Therapy Association
References
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