Medical Policy

This document addresses the use of gait modulation systems using rhythmic auditory stimulation (RAS), also known as neurologic music therapy. RAS has been proposed as a tool to improve gait, balance and other factors of walking during the physical rehabilitation of individuals who have neurological conditions such as stroke. Several devices have been developed to deliver RAS in unique ways.

Note: For information related to other rehabilitation services, please refer to the applicable guidelines used by the plan.

Note: For a high-level overview of this document, please see “Summary for Members and Families” below. 

Investigational and Not Medically Necessary:

Gait modulation systems using rhythmic auditory stimulation (RAS), also referred to as neurologic music therapy, is considered investigational and not medically necessary for all indications.

This document describes clinical studies and expert recommendations, and explains whether certain gait modulation systems using rhythmic auditory stimulation (RAS) are clinically appropriate. The following summary does not replace the medical necessity criteria or other information in this document. The summary may not contain all of the relevant criteria or information. This summary is not medical advice. Please check with your healthcare provider for any advice about your health.

Key Information

Gait modulation systems using RAS, also called neurologic music therapy, use sound cues such as music or beats to help improve walking. These systems are designed for people with neurologic conditions such as stroke and Parkinson disease. Some devices, such as MedRhythms InTandem and Movive, use sensors in shoes and headphones to adjust music in real time to match a person’s steps. The goal is to improve walking speed, balance, and coordination.

What the Studies Show

RAS uses repeated sounds or music to help the brain and body coordinate movement. Special devices may track a person’s steps and adjust the rhythm to guide walking. This is meant to improve walking speed, step length, and balance.

Studies in people who had a stroke show small improvements in walking speed and in some walking measures. In one 2024 study of the InTandem device, people using the device improved more than those who did not use the device. However, the difference between the groups was smaller than the amount experts consider meaningful for daily life. The study lasted only 5 weeks, and there was no long term follow up. Some people had side effects, including falls, high blood pressure, weakness, or chest pain. One case of chest pain may have been related to the device. In Parkinson disease, small studies showed improvement in walking and daily steps while using the device, but benefits decreased after stopping treatment. A small study in Huntington disease showed no clear benefit. Overall, the majority of studies looking at the use of test types of devices have been small, short in duration, or had design problems that make the results less reliable. Better studies are needed to know if RAS improves health over the long term and for different groups of people.

Is this clinically appropriate?

Gait modulation systems using RAS are not clinically appropriate because they have not been proven to improve health. This includes devices such as MedRhythms InTandem^® and Movive^®. Studies show some short-term changes in walking tests, but the improvements were often small and may not make a meaningful difference in daily life. Many studies included small numbers of people, lasted only a few weeks, or did not include strong comparison groups. In some studies, benefits went away after treatment stopped. There were also reports of harms such as falls, high blood pressure, weakness, and chest pain. Because the long term benefits are unclear and there are possible risks, the overall effects on peoples’ health has not been clearly shown.

(Return to Description/Scope)

Summary

Rhythmic auditory stimulation (RAS) has been studied primarily as a rehabilitation tool for stroke and other neurologic conditions, but the overall evidence base remains limited and heterogeneous. A 2022 systematic review in stroke populations found small, methodologically varied studies suggesting improvements in gait and walking function, though evidence for balance and long-term outcomes was insufficient. Accordingly, 2024 U.S. Department of Veterans Affairs and U.S. Department of Defense (VA/DoD) guidelines issued a weak recommendation for RAS as an adjunct therapy due to low-quality evidence. Early cohort studies of the InTandem device reported favorable short-term gait changes but were small and uncontrolled. A 2024 randomized controlled trial (RCT) in post-stroke individuals showed statistically greater improvements in walking speed with InTandem versus control, though the between-group difference did not meet the minimal clinically important difference and durability beyond 5 weeks was not assessed. In Parkinson disease, small studies, including a pilot and a modest RCT, reported improvements in gait metrics and physical activity during active use, but benefits diminished after discontinuation and methodological limitations restrict generalizability. A small case series examining use in Huntington disease found no significant benefit. Overall, while RAS and related gait modulation devices show potential, current evidence is limited by small samples, short durations, heterogeneity, and design weaknesses, and more rigorous trials are needed to establish clinical utility and long-term effectiveness.

Discussion

RAS has been proposed as a rehabilitation tool for individuals with neurological conditions, primarily those with stroke (Gonzalez‑Hoelling, 2024). A systematic review and meta-analysis by Wang (2022) describes evidence regarding the use of RAS for stroke rehabilitation. The authors noted that the number of studies meeting their inclusion criteria was limited (n=22) and the sample size of the included studies was generally low (range 11-78). There was high heterogeneity of methods and measured outcomes in the included studies with significant differences in intervention methods, use of control interventions (e.g., drug therapy, neurodevelopmental treatment, treadmill training, etc.), duration of treatment interventions (range 3 to 8 weeks), and the degree of experimental rigor. Some studies were blinded and some were not. The authors concluded that this study suggests that RAS could improve the gait parameters, walking function, and balance function of individuals with stroke, but the quality of studies is insufficient to determine the impact on balance ability of individuals who have had a stroke. They recommended future studies with more rigorous design “to obtain strong conclusions about the advantages of RAS for the treatment of gait and motor function in stroke.”

The 2024 VA/DoD joint clinical practice guideline for management of stroke rehabilitation include the following recommendation for RAS:

9. We suggest rhythmic auditory stimulation as an adjunct intervention to improve motor outcomes. (Weak for | Reviewed, New-replaced)

They provide the following rationale for this recommendation:

The Work Group’s confidence in the quality of the evidence was low. The body of evidence had limitations, including unclear allocation concealment, unclear blinding of outcome assessors, and significant variation in control interventions. The benefits slightly outweigh the potential harms/burdens, which do not appear to be any greater than with conventional therapies

Several cohort studies have reported on the use of the InTandem^® device (MedRhythms Inc., Portland, ME) (Collimore, 2013; Hutchinson, 2020; Smayda, 2023). The Smayda study evaluated the simulated use of the device, reporting on the ability of participants to understand and use the device appropriately. Smayada did not provide data related to the effects of the InTandem device on functional outcomes. The Collimore and Hutchinson studies were cohort studies (n=10 and n=11, respectively) with brief trial periods and no follow-up. While they reported favorable results with regard to step, stance and swing times, energy costs, and walking speeds, the presented data is limited and does not allow conclusions to be drawn about the effects of RAS in diverse populations and over long periods of time.

In 2024, Awad and colleagues reported the results of a prospective RCT that involved 87 participants older than 50 years of age and more than 6 months post-stroke. Participants were assigned to 5 weeks of walking rehabilitation with and without the InTandem device. A total of 15 30-minute walking sessions, 3 times a week over a 5-week period, were planned. The primary endpoints were the 10-meter walk test (10mWT) and safety. There were 6 participants who withdrew after randomization, leaving 81 participants who completed at least one session. Another participant had results outside 3.45 standard deviations of the study pool mean and their results were removed from the analysis. An additional 8 participants were excluded due to COVID related issues. The intent-to-treat analysis included 72 participants who completed at least one training session. The trial included a total of 1015 completed intervention sessions. Of these, 984 sessions (96.9%) were fully complete and 31 (3.1%) were terminated early. Of the 31 sessions terminated early, 15 were ≥ 15 minutes in duration and thus did not require restart or rescheduling as per the trial protocol. A total of 13 sessions were incomplete due to software or system component issues that rapidly resolved, allowing uneventful completion the same day. The InTandem group had a significantly faster 10mWT speed compared to the control group (0.14 ± 0.03 m/s vs. 0.06 ± 0.02 m/s, respectively; p=0.013). The authors considered the Minimal Clinical Important Difference (MCID) for the 10mWT to be 0.16 m/s. Among the 40 InTandem group participants, 16 (40%) improved performance in the 10mWT by more than 0.16 m/s. Only 4 of 32 (12.5%) of the control group improved in the 10mWT by more than 0.16 m/s. However, the study’s primary endpoint was the between-group difference in the change in the 10mWT. The InTandem group experienced an average (± standard error) increase in 10 mWT speed of 0.14 ± 0.03 m/s while the active control group’s average increase was 0.06 ± 0.02 m/s. This corresponds to a between-group difference of 0.08 m/s which is lower than the MCID of 0.16 m/s. A total of 10 adverse events and 2 serious adverse events were reported for 7 InTandem group participants. The adverse events possibly related to the InTandem device included a fall and hypertension. The serious adverse events included weakness and chest pain. Only the chest pain was deemed possibly related to the InTandem device, as it occurred during a walking session. The event resolved within a day and the participant completed the trial on schedule. In the control group, 7 participants (21.9%) experienced adverse events, 2 of which were considered serious adverse events. However, neither was deemed related to the walking sessions. A total of 6 falls were reported during the trial: 4 in the control group and 2 in the InTandem group. No injuries resulted from the 6 falls. These falls occurred outside of trial visit, and were considered “not related” or “unlikely related” to the RAS therapy. The authors concluded that ”further study is warranted to better understand the feasibility and rehabilitative potential of using InTandem in home settings, the ideal length of treatment, the durability of effect, and healthcare resource utilization impact…” This study had several limitations, including the entry criteria selected participants were able to walk at speeds between 0.50 m/s and 0.80 m/s. Generalizability to individuals not able to walk at these baseline speeds is unknown. The study’s measurement period was only 5 weeks and there was no follow-up or reassessment period, so longer-term effects are unknown. This industry-sponsored study’s lack of blinding of assessors increases the possibility that observer bias may have influenced some of the results.

RAS has been investigated for the treatment of other conditions. In 2023, Zajac reported a pilot case series study involving 23 participants with mild to moderate Parkinson disease who used the MedRhythms MR-005 walking intervention RAS system. The study protocol required participants to complete 30-minute sessions of unsupervised, overground walking with music-based cues 5 times a week for 4 weeks. Metrics recorded included gait speed (m/s), stride length (m), cadence (steps/min), gait symmetry (interlimb swing time ratio), and gait variability (coefficient of variation (%) of stride-by-stride gait cycle duration). Daily minutes of moderate intensity walking and daily steps were also recorded. Participants completed a mean of 17.2 (86.4%) of the 20 total sessions per participant required by the protocol, resulting in a reported adherence of 86.4%. The mean session length was 39.0 minutes, 131.1% of the expected 30-minute duration. No adverse events (e.g., trips or falls) were reported. The authors reported that use of the MR-005 resulted in faster walking speeds (p<0.001), longer strides (p<0.001), higher walking cadence (p<0.001), and lower gait variability (p<0.001). Gait symmetry remained unchanged (p>0.05). Compared to baseline, the results on the Movement Disorders Society-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) Part III (motor) score indicated improved disease severity (p=0.01), while results on the Six-Minute Walk Test (6MWT) times indicated improved walking endurance (p=0.04). Results on the Five Times Sit to Stand Test (FTSTST) showed improved functional mobility (p=0.001). A statistically significant improvement was observed in the PDQ-39 total score (p=0.027); however, the mean change of -2.68 points did not reach the minimal clinically important difference (MCID), which is generally considered to be approximately 4-5 points. No significant change was observed in the PDQ-39 mobility subscale. No significant difference was noted in the Ten Meter Walk Test (10MWT). Overall, these results suggest that RAS may be associated with potential improvements in physical function and motor severity. However, causal conclusions cannot be drawn due to the uncontrolled study design. Limitations of this study include the lack of a control group, blinding, use of participants with mild to moderate Parkinson disease, and the small participant pool. These design features limit the ability to attribute observed changes to the intervention and restrict the generalizability of the findings to broader Parkinson disease populations. Larger, well-designed RCTs with longer follow-up are needed to more definitively assess safety, durability, and clinical effectiveness.

Porciuncula (2025) reported the results of an assessor blinded RCT involving 44 participants with mild Parkinson disease randomized to use of the MR-005 RAS device or to an active control consisting of community walking without RAS. Although there were 22 participants in each study arm, 41 participants were included in analyses (21 RAS, 20 control). The baseline period involved 6 weeks of routine real-world walking in the community. That was followed by 6 weeks using the assigned intervention. The trial concluded with a 2-week period of real-world walking with no specific instructions or monitoring. Loss to follow-up included one participant in the RAS group and two in the control group. Adherence was high in both groups during the 6-week trial period, but engagement appeared lower in the control group during the follow-on period. There were no adverse events reported in the RAS group and 2 injurious falls not requiring medical attention in the control group. During the 6-week walking intervention period the RAS group gained 23.38 ± 8.84 min of walking per day compared to 6.91 ± 18 min gained per day by the control group (p=0.001). During the 2 week real-world period the RAS group the gained 20.85 ± 11.16 min of walking daily compared to 8.0 ± 20.18 min gained by the control group (p=0.021). However, all between-group differences disappeared after 8 weeks at post-program completion. During the 6 week trial phase, the RAS group gained significantly more daily steps relative to baseline (3343 ± 1642) compared to 172 ± 4009 steps gained by the Control group (p=0.003). This between-group difference dissipated at post-program completion (p=0.207). During the 6-week trial phase the RAS group demonstrated a decrease (improvement) in stride time variability (STV) relative to baseline, whereas STV in the Active-Control group increased (p=0.029). At the completion of the trial, 84% of participants in the RAS group reported favorable changes in overall physical activity, as reflected on the Global Rating of Change scale, in comparison to 58% of participants in the control group. Although these findings suggest potential benefits of the RAS intervention, interpretation is limited by the small sample size, short study duration, enrollment of participants with mild disease, and the relatively simple control intervention.

Baudendistel (2025) reported on the results of a prospective cross sectional study involving 22 participants with Huntington disease who completed instrumented testing during 4 walking conditions: comfortable pace, cognitive dual task, external musical cueing (listening), and internal cueing (singing). Walking trials were conducted in a 100 foot hallway walk with cueing set to 110% of the baseline cadence. Compared to baseline walking, neither musical listening nor singing significantly improved cadence, stride length, or velocity (all p=1.000 after correction). However, both cueing conditions significantly increased stride length and stride time variability. The authors concluded that RAS did not improve gait and may worsen gait stability in this population. The generalizability of these findings is limited due to the small sample size and other methodological limitations.

Overall, the evidence regarding the clinical utility of the InTandem devices, and gait modulation systems using RAS, is limited and non-generalizable. Additional data in the form of rigorously designed and executed studies is need.

Rhythmic auditory stimulation (RAS), or neurologic music therapy, is a rehabilitation service that involves the use of rhythmic auditory cues in the form of regular, patterned sounds or metrically accentuated music to coordinate an individual’s pattern of movement with the goal of improving motor and physical function following neurological impairment. This has been said to target the automatic processes in the central and peripheral nervous system to induce auditory motor entrainment, described as a neurally-mediated process where the timing of motor movements is involuntarily synchronized with the timing of a rhythmic auditory stimulus. The has been said to unconsciously reprogram and synchronize the auditory and motor systems and improve motor function in the targeted anatomical system.

Several devices have been developed to deliver RAS. While RAS may be delivered using a simple metronome or carefully selected music, more recently new technologically advanced methods for delivering RAS have been proposed. The MedRhythms Inc. InTandem autonomous neurorehabilitation system has been proposed to deliver RAS for walking rehabilitation of individuals who have experienced a stroke. The system is composed of three parts: shoe-worn inertial sensors, a control unit, and a headset. The control unit is loaded with a proprietary RAS-based treatment algorithm and music. Data from the shoe sensors regarding stride, step tempo, and other factors, is delivered and processed by the control unit’s algorithm, which then provides automatically adjusted music-based rhythmic cues to the headset in real time to influence an individual’s gait. The system senses therapy progression and automatically adjusts the auditory stimulation to align with an individual’s performance and needs in a closed-loop fashion, with the goal of individualizing the delivered therapy without the need for a clinician’s intervention. A similar system, Movive™, is also marketed by MedRhythms.   

MedRhythms describes the InTandem system as a prescription-only medical device intended for individuals 6 months or more post-stroke for gait impairment, slow walking speed, asymmetry, and effortful gait, factors associated with fall risk, reduced ability to perform ambulation-related ADLs. The device is recommended for use 3 times per week for 30 minutes each session. The Movive device is indicated to support gait rehabilitation and motor function for people living with Parkinson disease.

The following codes for treatments and procedures applicable to this document are included below for informational purposes. Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When services are Investigational and Not Medically Necessary:
For the following procedure code, or when the code describes a procedure indicated in the Position Statement section as investigational and not medically necessary.

Peer Reviewed Publications:

1. Awad LN, Jayaraman A, Nolan KJ, et al. Efficacy and safety of using auditory-motor entrainment to improve walking after stroke: a multi-site randomized controlled trial of InTandem^™. Nat Commun. 2024; 15(1):1081.
2. Baudendistel ST, Tueth LE, Haussler AM, Earhart GM. Musical distractions: music-based rhythmic auditory stimulation fails to improve gait in Huntington's disease. Brain Sci. 2025; 15(8):820.
3. Collimore AN, Roto Cataldo AV, Aiello AJ, et al. Autonomous control of music to retrain walking after stroke. Neurorehabil Neural Repair. 2023; 37(5):255-265.
4. Gonzalez-Hoelling S, Reig-García G, et al. The effects of rhythmic auditory stimulation on functional ambulation after stroke: a systematic review. BMC Complement Med Ther. 2024; 24(1):45.
5. Hutchinson K, Sloutsky R, Collimore A, et al. A music-based digital therapeutic: proof-of-concept automation of a progressive and individualized rhythm-based walking training program after stroke. Neurorehabil Neural Repair. 2020; 34(11):986-996.
6. Smayda KE, Cooper SH, Leyden K, et al. Validating the safe and effective use of a neurorehabilitation system (intandem) to improve walking in the chronic stroke population: usability study. JMIR Rehabil Assist Technol. 2023; 10:e50438.
7. Wang L, Peng JL, Xiang W, et al. Effects of rhythmic auditory stimulation on motor function and balance ability in stroke: a systematic review and meta-analysis of clinical randomized controlled studies. Front Neurosci. 2022; 16:1043575.
8. Zajac JA, Porciuncula F, Cavanaugh JT, et al. Feasibility and proof-of-concept of delivering an autonomous music-based digital walking intervention to persons with Parkinson's disease in a naturalistic setting. J Parkinsons Dis. 2023; 13(7):1253-1265.

Government Agency, Medical Society, and Other Authoritative Publications:

1. U.S. Department of Veterans Affairs and U.S. Department of Defense. VA/DoD clinical practice guideline for management of stroke rehabilitation. 2024. Available at: https://www.healthquality.va.gov/guidelines/Rehab/stroke/index.asp. Accessed on May 5, 2026.

1. Centers for Disease Control and Prevention. Treatment and Intervention for Stroke. May 15, 2024. Available at: https://www.cdc.gov/stroke/treatment/index.html. Accessed on May 5, 2026.
2. National Institute of Neurological Disorders and Stroke. Stroke recovery. Last reviewed on January 28, 2026. Available at: https://www.ninds.nih.gov/health-information/stroke/recovery. Accessed on May 5, 2026.

InTandem
MedRhythms
Movive
Neurologic music therapy
RAS
Rhythmic auditory stimulation

The use of specific product names is illustrative only. It is not intended to be a recommendation of one product over another, and is not intended to represent a complete listing of all products available.

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