Beat perception ability and instructions to synchronize influence gait when walking to music-based auditory cues

The Ramp protocol: Uncovering individual differences in walking to an auditory beat using TeensyStep

Intentionally walking to the beat of an auditory stimulus seems effortless for most humans. However, studies have revealed significant individual differences in the spontaneous tendency to synchronize. Some individuals tend to adapt their walking pace to the beat, while others show little or no adjustment. To fill this gap we introduce the Ramp protocol, which measures spontaneous adaptation to a change in an auditory rhythmic stimulus in a gait task. First, participants walk at their preferred cadence without stimulation. After several steps, a metronome is presented, timed to match the participant's heel-strike. Then, the metronome tempo progressively departs from the participant's cadence by either accelerating or decelerating. The implementation of the Ramp protocol required real-time detection of heel-strike and auditory stimuli aligned with participants' preferred cadence. To achieve this, we developed the TeensyStep device, which we validated compared to a gold standard for step detection. We also demonstrated the sensitivity of the Ramp protocol to individual differences in the spontaneous response to a tempo-changing rhythmic stimulus by introducing a new measure: the Response Score. This new method and quantification of spontaneous response to rhythmic stimuli holds promise for highlighting and distinguishing different profiles of adaptation in a gait task.

Evaluation of physiological response and synchronisation errors during synchronous and pseudosynchronous stimulation trials

Rhythm perception and synchronisation is musical ability with neural basis defined as the ability to perceive rhythm in music and synchronise body movements with it. The study aimed to check the errors of synchronisation and physiological response as a reaction of the subjects to metrorhythmic stimuli of synchronous and pseudosynchronous stimulation (synchronisation with an externally controlled rhythm, but in reality controlled or produced tone by tapping) Nineteen subjects without diagnosed motor disorders participated in the study. Two tests were performed, where the electromyography signal and reaction time were recorded using the NORAXON system. In addition, physiological signals such as electrodermal activity and blood volume pulse were measured using the Empatica E4. Study 1 consisted of adapting the finger tapping test in pseudosynchrony with a given metrorhythmic stimulus with a selection of preferred, choices of decreasing and increasing tempo. Study 2 consisted of metrorhythmic synchronisation during the heel stomping test. Numerous correlations and statistically significant parameters were found between the response of the subjects with respect to their musical education, musical and sports activities. Most of the differentiating characteristics shown evidence of some group division in the undertaking of musical activities. The use of detailed analyses of synchronisation errors can contribute to the development of methods to improve the rehabilitation process of subjects with motor dysfunction, and this will contribute to the development of an expert system that considers personalised musical preferences.

A review of psychological and neuroscientific research on musical groove

When listening to music, we naturally move our bodies rhythmically to the beat, which can be pleasurable and difficult to resist. This pleasurable sensation of wanting to move the body to music has been called "groove." Following pioneering humanities research, psychological and neuroscientific studies have provided insights on associated musical features, behavioral responses, phenomenological aspects, and brain structural and functional correlates of the groove experience. Groove research has advanced the field of music science and more generally informed our understanding of bidirectional links between perception and action, and the role of the motor system in prediction. Activity in motor and reward-related brain networks during music listening is associated with the groove experience, and this neural activity is linked to temporal prediction and learning. This article reviews research on groove as a psychological phenomenon with neurophysiological correlates that link musical rhythm perception, sensorimotor prediction, and reward processing. Promising future research directions range from elucidating specific neural mechanisms to exploring clinical applications and socio-cultural implications of groove.

Gait Variability at Different Walking Speeds

Gait variability (GV) is a crucial measure of inconsistency of muscular activities or body segmental movements during repeated tasks. Hence, GV might serve as a relevant and sensitive measure to quantify adjustments of walking control. However, it has not been clarified whether GV is associated with walking speed, a clarification needed to exploit effective better bilateral coordination level. For this aim, fourteen male students (age 22.4 ± 2.7 years, body mass 74.9 ± 6.8 kg, and body height 1.78 ± 0.05 m) took part in this study. After three days of walking 1 km each day at a self-selected speed (SS) on asphalt with an Apple Watch S. 7 (AppleTM, Cupertino, CA, USA), the participants were randomly evaluated on a treadmill at three different walking speed intensities for 10 min at each one, SS - 20%/SS + 20%/ SS, with 5 min of passive recovery in-between. Heart rate (HR) was monitored and normalized as %HRmax, while the rate of perceived exertion (RPE) (CR-10 scale) was asked after each trial. Kinematic analysis was performed, assessing the Contact Time (CT), Swing Time (ST), Stride Length (SL), Stride Cycle (SC), and Gait Variability as Phase Coordination Index (PCI). RPE and HR increased as the walking speed increased (p = 0.005 and p = 0.035, respectively). CT and SC decreased as the speed increased (p = 0.0001 and p = 0.013, respectively), while ST remained unchanged (p = 0.277). SL increased with higher walking speed (p = 0.0001). Conversely, PCI was 3.81 ± 0.88% (high variability) at 3.96 ± 0.47 km·h-1, 2.64 ± 0.75% (low variability) at SS (4.94 ± 0.58 km·h-1), and 3.36 ± 1.09% (high variability) at 5.94 ± 0.70 km·h-1 (p = 0.001). These results indicate that while the metabolic demand and kinematics variables change linearly with increasing speed, the most effective GV was observed at SS. Therefore, SS could be a new methodological approach to choose the individual walking speed, normalize the speed intensity, and avoid a gait pattern alteration.

Beat cues facilitate time estimation at longer intervals

Introduction

Time perception in humans can be relative (beat-based) or absolute (duration-based). Although the classic view in the field points to different neural substrates underlying beat-based vs. duration-based mechanisms, recent neuroimaging evidence provided support to a unified model wherein these two systems overlap. In line with this, previous research demonstrated that internalized beat cues benefit motor reproduction of longer intervals (> 5.5 s) by reducing underestimation, but little is known about this effect on pure perceptual tasks. The present study was designed to investigate whether and how interval estimation is modulated by available beat cues.

Methods

To that end, we asked 155 participants to estimate auditory intervals ranging from 500 ms to 10 s, while manipulating the presence of cues before the interval, as well as the reinforcement of these cues by beat-related interference within the interval (vs. beat-unrelated and no interference).

Results

Beat cues aided time estimation depending on interval duration: for intervals longer than 5 s, estimation was better in the cue than in the no-cue condition. Specifically, the levels of underestimation decreased in the presence of cues, indicating that beat cues had a facilitating effect on time perception very similar to the one observed previously for time production.

Discussion

Interference had no effects, suggesting that this manipulation was not effective. Our findings are consistent with the idea of cooperation between beat- and duration-based systems and suggest that this cooperation is quite similar across production and perception.

Comparative analysis of the effect of interactive audio-visual based art therapy and music therapy in reducing suicidal ideation among school children who survived abduction

This study looked at how exposure to interactive TV-based music and art therapy could assist in reducing suicidal thoughts of secondary school female children who survived abduction in Nigeria. A quasi-experiment was carried out in three randomly selected secondary schools in Northern Nigeria. The study sample comprised 470 students divided into three groups to form control group 235, art therapy group 118 and music therapy group 117. Results suggest that participants exposed to interactive TV-based art therapy and music therapy reported a lower score for suicidal ideation compared to the control group that was not exposed to any form of therapy aside from routine clinic checkups. Specifically, those exposed to interactive TV-based art therapy reported a lesser suicidal ideation score than the music and the control group. We recommend the introduction of interactive TV-based music therapy and art therapy in reducing suicidal ideation among children that survived kidnapping in Nigeria.

Effects of music therapy intervention on gait disorders in persons with multiple sclerosis: A systematic review of clinical trials

BACKGROUND

Music Therapy (MT) is a unique treatment method for Persons with Multiple Sclerosis (PwMS) that can accelerate their functional recovery. MT has been proven to adjust the gait performance of PwMS in a short period. Its therapeutic effects in gait disorders of PwMS for long-term intervention are also starting to draw interest, but it has yet to be investigated.

AIM

This review aimed to systematically examine the outcomes of PwMS with gait disorders after receiving MT intervention.

METHODS

A systematic review has been performed using several academic databases with keywords such as music therapy, multiple sclerosis, and gait. The study protocol was registered on PROSPERO (CRD42022365668).

RESULTS

A total of 405 studies were initially identified. After applying the inclusion and exclusion criteria, twelve studies were finally included. The results showed that all PwMS received MT intervention with different strategies, and ten studies confirmed that gait disorders of PwMS were effectively improved by MT intervention.

CONCLUSION

Most previous studies focused on the transient effects of MT on the gait performance of PwMS. This review bridges gaps in the long-term intervention of MT on gait disorders of PwMS and offers references for therapists to design treatment plans. According to this review, MT intervention has positive therapeutic effects on gait disorders in PwMS.

The effect of biomechanical features on classification of dual-task gait

Early detection of Alzheimer's Disease and Related Disorders (ADRD) has been a focus of research with the hope that early intervention may improve clinical outcomes. The manifestation of motor impairment in early stages of ADRD has led to the inclusion of gait assessments including spatiotemporal parameters in clinical evaluations. This study aims to determine the effect of adding kinetic and kinematic gait features to classification of different levels of cognitive load in healthy individuals. A dual-task paradigm was used to simulate cognitive impairment in 40 healthy adults, with single-task walking trials representing normal, healthy gait. The Paced Auditory Serial Addition Task was administered at two different inter-stimulus intervals representing two levels of cognitive load in dual-task gait. We predicted that a richer dataset would improve classification accuracy relative to spatiotemporal parameters. Repeated Measures ANOVA showed significant changes in 15 different gait features across all three levels of cognitive load. We used three supervised machine learning algorithms to classify data points using a series of different gait feature sets with performance based on the area under the curve (AUC). Classification yielded 0.778 AUC across all three conditions (0.889 AUC Single vs. Dual) using kinematic and spatiotemporal features compared to 0.724 AUC using spatiotemporal features only (0.792 AUC Single vs. Dual). These data suggest that additional kinematic parameters improve classification performance. However, the benefit of measuring a wider set of parameters compared to their cost needs consideration. Further work will lead to a clinically viable ADRD detection classifier.

Neurologic Music Therapy in Geriatric Rehabilitation: A Systematic Review

(1) Introduction: Neurologic music therapy (NMT) is a non-pharmacological approach of interaction through the therapeutic use of music in motor, sensory and cognitive dysfunctions caused by damage or diseases of the nervous system. (2) Objective: This study aimed to critically appraise the available literature on the application of particular NMT techniques in the rehabilitation of geriatric disorders. (3) Methods: PubMed, ScienceDirect and EBSCOhost databases were searched. We considered randomized controlled trials (RCTs) from the last 12 years using at least one of the NMT techniques from the sensorimotor, speech/language and cognitive domains in the therapy of patients over 60 years old and with psychogeriatric disorders. (4) Results: Of the 255 articles, 8 met the inclusion criteria. All papers in the final phase concerned the use of rhythmic auditory stimulation (RAS) (sensorimotor technique) in the rehabilitation of both Parkinson's disease (PD) patients (six studies) and stroke patients (SPs) (two studies). (5) Conclusion: All reports suggest that the RAS technique has a significant effect on the improvement of gait parameters and the balance of PD patients and SPs, as well as the risk of falls in PD patients.

Gait in younger and older adults during rhythmic auditory stimulation is influenced by groove, familiarity, beat perception, and synchronization demands

Music-based Rhythmic auditory stimulation (RAS) is a cueing intervention used to regulate gait impairments in conditions such as Parkinson's disease or stroke. Desire to move with music ('groove') and familiarity have been shown to impact younger adult gait while walking with music, and these effects appear to be influenced by individual rhythmic ability. Importantly, these factors have not been examined in older adults. The aim of this study was to determine how gait outcomes during RAS are influenced by musical properties (familiarity, 'groove') in both free and synchronized walking for younger and older adults with good and poor beat perception ability. To do this, participants were randomized to either free or synchronized walking groups. Each participant's gait was assessed on a pressure sensitive walkway during high versus low groove and high versus low familiarity music, as well as metronome, cueing trials. Individual beat perception ability was evaluated using the Beat Alignment Test. Results showed that the effects of synchronization and groove were mostly consistent across age groups. High groove music elicited faster gait in both age groups, with longer strides only among young adults, than low groove music; synchronizing maximized these effects. Older adults with poor beat perception were more negatively affected by unfamiliar stimuli while walking than younger adults. This suggests that older adults, like younger adults, may benefit from synchronized RAS to high groove cues but may be more vulnerable to cognitive demands associated with walking to unfamiliar stimuli. This should be accounted for in clinical implementations of RAS.

The effects of Parkinson's disease, music training, and dance training on beat perception and production abilities

Humans naturally perceive and move to a musical beat, entraining body movements to auditory rhythms through clapping, tapping, and dancing. Yet the accuracy of this seemingly effortless behavior varies widely across individuals. Beat perception and production abilities can be improved by experience, such as music and dance training, and impaired by progressive neurological changes, such as in Parkinson’s disease. In this study, we assessed the effects of music and dance experience on beat processing in young and older adults, as well as individuals with early-stage Parkinson’s disease. We used the Beat Alignment Test (BAT) to assess beat perception and production in a convenience sample of 458 participants (278 healthy young adults, 139 healthy older adults, and 41 people with early-stage Parkinson’s disease), with varying levels of music and dance training. In general, we found that participants with over three years of music training had more accurate beat perception than those with less training (p < .001). Interestingly, Parkinson’s disease patients with music training had beat production abilities comparable to healthy adults while Parkinson’s disease patients with minimal to no music training performed significantly worse. No effects were found in healthy adults for dance training, and too few Parkinson’s disease patients had dance training to reliably assess its effects. The finding that musically trained Parkinson’s disease patients performed similarly to healthy adults during a beat production task, while untrained patients did not, suggests music training may preserve certain rhythmic motor timing abilities in early-stage Parkinson’s disease.

Gait Entrainment to Torque Pulses from a Hip Exoskeleton Robot

Robot-aided locomotor rehabilitation has proven challenging. To facilitate progress, it is important to first understand the neuro-mechanical dynamics and control of unimpaired human locomotion. Our previous studies found that human gait entrained to periodic torque pulses at the ankle when the pulse period was close to preferred stride duration. Moreover, synchronized gait exhibited constant phase relation with the pulses so that the robot provided mechanical assistance. To test the generality of mechanical gait entrainment, this study characterized unimpaired human subjects' responses to periodic torque pulses during overground walking. The intervention was applied by a hip exoskeleton robot, Samsung GEMS-H. Gait entrainment was assessed based on the time-course of the phase at which torque pulses occurred within each stride. Experiments were conducted for two consecutive days to evaluate whether the second day elicited more entrainment. Whether entrainment was affected by the difference between pulse period and preferred stride duration was also assessed. Results indicated that the intervention evoked gait entrainment that occurred more often when the period of perturbation was closer to subjects' preferred stride duration, but the difference between consecutive days was insignificant. Entrainment was accompanied by convergence of pulse phase to a similar value across all conditions, where the robot maximized mechanical assistance. Clear evidence of motor adaptation indicated the potential of the intervention for rehabilitation. This study quantified important aspects of the nonlinear neuro-mechanical dynamics underlying unimpaired human walking, which will inform the development of effective approaches to robot-aided locomotor rehabilitation, exploiting natural dynamics in a minimally-encumbering way.

An ecological approach to measuring synchronization abilities across the animal kingdom

In this perspective paper, we focus on the study of synchronization abilities across the animal kingdom. We propose an ecological approach to studying nonhuman animal synchronization that begins from observations about when, how and why an animal might synchronize spontaneously with natural environmental rhythms. We discuss what we consider to be the most important, but thus far largely understudied, temporal, physical, perceptual and motivational constraints that must be taken into account when designing experiments to test synchronization in nonhuman animals. First and foremost, different species are likely to be sensitive to and therefore capable of synchronizing at different timescales. We also argue that it is fruitful to consider the latent flexibility of animal synchronization. Finally, we discuss the importance of an animal's motivational state for showcasing synchronization abilities. We demonstrate that the likelihood that an animal can successfully synchronize with an environmental rhythm is context-dependent and suggest that the list of species capable of synchronization is likely to grow when tested with ecologically honest, species-tuned experiments.

This article is part of the theme issue ‘Synchrony and rhythm interaction: from the brain to behavioural ecology’.

Musical enjoyment does not enhance walking speed in healthy adults during music-based auditory cueing

BACKGROUND

Rhythmic Auditory Stimulation (RAS) involves synchronizing footsteps to music or a metronome to improve gait speed and stability in patients with neurological disorders, such as Parkinson's disease. However, responses to RAS vary across individuals, perhaps because of differences in enjoyment of the music or in musical abilities.

RESEARCH QUESTION

Intuitively, musical enjoyment may influence gait responses to RAS, but enjoyment has not been systematically manipulated nor the effects empirically assessed. In addition, differences in beat perception ability are likely to influence gait responses to music, particularly when synchronizing to the beat. Therefore, we asked: how does music enjoyment alter gait, and do gait parameters differ between individuals with good versus poor beat perception ability, specifically when instructed to 'walk freely' versus 'synchronize to the beat'?

METHOD

Young adults and older adults walked on a pressure sensor walkway in silence and to music that they had rated as either high or low in enjoyment, as well as a metronome. All stimuli were presented at 15 % faster than baseline cadence. Participants either walked freely to the music or synchronized to the beat.

RESULTS

Music enjoyment had no significant effects on gait in either younger or older adults. Compared to baseline, younger adults walked faster (by taking longer strides) to music than the metronome, whereas older adults walked faster (by taking more steps per minute) to the metronome than music. When instructed to synchronize vs. walk freely, young adults walked faster, but older adults walked slower. Finally, regardless of instruction type, young adults with poor beat perception took shorter and slower strides to the music, whereas older adults with poor beat perception took slower strides to the music.

SIGNIFICANCE

Beat perception ability, instruction type, and age affect gait more than music enjoyment does, and thus should be considered when optimizing RAS outcomes.

The Effect of Rhythm Abilities on Metronome-Cued Walking with an Induced Temporal Gait Asymmetry in Neurotypical Adults

ABSRACT. Human gait is inherently rhythmical, thus walking to rhythmic auditory stimulation is a promising intervention to improve temporal gait asymmetry (TGA) following neurologic injury such as stroke. However, the degree of benefit may relate to an individual's underlying rhythmic ability. We conducted an initial investigation into the relationship between rhythm abilities and responsiveness of TGA when walking to a metronome. TGA was induced in neurotypical young adults with ankle and thigh cuff weights. Participants were grouped by strong or weak rhythm ability based on beat perception and production tests. TGA was induced using a unilateral load affixed to the non-dominant leg. Participants walked under three conditions: uncued baseline, metronome set to 100% of baseline cadence, and metronome set to 90% of baseline cadence. Repeated measures analysis using generalized estimating equations was conducted to determine how rhythm ability affected TGA response in each walking condition. Most participants improved TGA when walking to a metronome at either tempo compared to baseline; however, this improvement did not differ between strong and weak rhythm ability groups. Those who scored worse on the rhythm perception test also were poorer at synchronizing their steps to the beat. The induced TGA is smaller than what is commonly experienced after stroke. A larger induced TGA may be necessary to reveal subtle differences in responsiveness to rhythmical auditory stimulation between those with strong and weak rhythm abilities.

Adapting Footfall Rhythmicity to Auditory Perturbations Affects Resilience of Locomotor Behavior: A Proof-of-Concept Study

For humans, the ability to effectively adapt footfall rhythm to perturbations is critical for stable locomotion. However, only limited information exists regarding how dynamic stability changes when individuals modify their footfall rhythm. In this study, we recorded 3D kinematic activity from 20 participants (13 males, 18–30 years old) during walking on a treadmill while synchronizing with an auditory metronome sequence individualized to their baseline walking characteristics. The sequence then included unexpected temporal perturbations in the beat intervals with the subjects required to adapt their footfall rhythm accordingly. Building on a novel approach to quantify resilience of locomotor behavior, this study found that, in response to auditory perturbation, the mean center of mass (COM) recovery time across all participants who showed deviation from steady state (N = 15) was 7.4 (8.9) s. Importantly, recovery of footfall synchronization with the metronome beats after perturbation was achieved prior (+3.4 [95.0% CI +0.1, +9.5] s) to the recovery of COM kinematics. These results highlight the scale of temporal adaptation to perturbations and provide implications for understanding regulation of rhythm and balance. Thus, our study extends the sensorimotor synchronization paradigm to include analysis of COM recovery time toward improving our understanding of an individual’s resilience to perturbations and potentially also their fall risk.

How groove in music affects gait

Rhythmic auditory stimulation (RAS) is a gait intervention in which gait-disordered patients synchronise footsteps to music or metronome cues. Musical 'groove', the tendency of music to induce movement, has previously been shown to be associated with faster gait, however, why groove affects gait remains unclear. One mechanism by which groove may affect gait is that of beat salience: music that is higher in groove has more salient musical beats, and higher beat salience might reduce the cognitive demands of perceiving the beat and synchronizing footsteps to it. If groove's effects on gait are driven primarily by the impact of beat salience on cognitive demands, then groove's effects might only be present in contexts in which it is relevant to reduce cognitive demands. Such contexts could include task parameters that increase cognitive demands (such as the requirement to synchronise to the beat), or individual differences that may make synchronisation more cognitively demanding. Here, we examined whether high beat salience can account for the effects of high-groove music on gait. First, we increased the beat salience of low-groove music to be similar to that of high-groove music by embedding metronome beats in low and high-groove music. We examined whether low-groove music with high beat salience elicited similar effects on gait as high-groove music. Second, we examined the effect of removing the requirement to synchronise footsteps to the beat (i.e., allowing participants to walk freely with the music), which is thought to remove the cognitive demand of synchronizing movements to the beat. We tested two populations thought to be sensitive to the cognitive demands of synchronisation, weak beat-perceivers and older adults. We found that increasing the beat salience of low-groove music increased stride velocity, but strides were still slower than with high-groove music. Similarly, removing the requirement to synchronise elicited faster, less variable gait, and reduced bias for stability, but high-groove music still elicited faster strides than low-groove music. These findings suggest that beat salience contributes to groove's effect on gait, but it does not fully account for it. Despite reducing task difficulty by equalizing beat salience and removing the requirement to synchronise, high-groove music still elicited faster, less variable gait. Therefore, other properties of groove also appear to play a role in groove's effect on gait.

BeatWalk: Personalized Music-Based Gait Rehabilitation in Parkinson's Disease

Taking regular walks when living with Parkinson’s disease (PD) has beneficial effects on movement and quality of life. Yet, patients usually show reduced physical activity compared to healthy older adults. Using auditory stimulation such as music can facilitate walking but patients vary significantly in their response. An individualized approach adapting musical tempo to patients’ gait cadence, and capitalizing on these individual differences, is likely to provide a rewarding experience, increasing motivation for walk-in PD. We aim to evaluate the observance, safety, tolerance, usability, and enjoyment of a new smartphone application. It was coupled with wearable sensors (BeatWalk) and delivered individualized musical stimulation for gait auto-rehabilitation at home. Forty-five patients with PD underwent a 1-month, outdoor, uncontrolled gait rehabilitation program, using the BeatWalk application (30 min/day, 5 days/week). The music tempo was being aligned in real-time to patients’ gait cadence in a way that could foster an increase up to +10% of their spontaneous cadence. Open-label evaluation was based on BeatWalk use measures, questionnaires, and a six-minute walk test. Patients used the application 78.8% (±28.2) of the prescribed duration and enjoyed it throughout the program. The application was considered “easy to use” by 75% of the patients. Pain, fatigue, and falls did not increase. Fear of falling decreased and quality of life improved. After the program, patients improved their gait parameters in the six-minute walk test without musical stimulation. BeatWalk is an easy to use, safe, and enjoyable musical application for individualized gait rehabilitation in PD. It increases “walk for exercise” duration thanks to high observance.

Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT02647242.

Effect of Short-Term Metro-Rhythmic Stimulations on Gait Variability

The aim of the study was to define the effect of different short-term metro-rhythmic stimulations on the time and spatial parameters of gait. The secondary goal was to test whether prior instructions on how to respond to stimulations played a significant role in the stimulation by sound stimuli. Experimental tests of gait were conducted on a group of 36 healthy participants: group 1—subjects who were not informed how to react after hearing sound stimuli, group 2—subjects who received a clear instruction before the test to adjust the frequency of taking steps to the rhythm of the music. The gait research was carried out on a Zebris FDM-S (zebris Medical Gmbh, Isny, Germany) treadmill for various sound stimuli (arrhythmic stimulus, rhythmic stimuli at different rate). It was shown that a short-term influence of metro-rhythmic stimulations changes the time and spatial parameters of gait, i.e., gait frequency, length and duration of the gait cycle. The greatest impact on the modification of the time–space parameters of walking is exerted by rhythmic stimuli at a pace different from the frequency of gait at a preferred velocity. Providing information on how to respond to sounds heard may be important in gait therapy with RAS (rhythmic auditory stimulation).

An Initial Investigation of the Responsiveness of Temporal Gait Asymmetry to Rhythmic Auditory Stimulation and the Relationship to Rhythm Ability Following Stroke

Temporal gait asymmetry (TGA) is a persistent post-stroke gait deficit. Compared to conventional gait training techniques, rhythmic auditory stimulation (RAS; i.e., walking to a metronome) has demonstrated positive effects on post-stroke TGA. Responsiveness of TGA to RAS may be related to several factors including motor impairment, time post-stroke, and individual rhythm abilities. The purpose of this study was to investigate the relationship between rhythm abilities and responsiveness of TGA when walking to RAS. Assessed using behavioral tests of beat perception and production, participants with post-stroke TGA (measured as single limb support time ratio) were categorized according to rhythm ability (as strong or weak beat perceivers/producers). We assessed change in TGA between walking without cues (baseline) and walking while synchronizing footsteps with metronome cues. Most individuals with stroke were able to maintain or improve TGA with a single session of RAS. Within-group analyses revealed a difference between strong and weak rhythm ability groups. Strong beat perceivers and producers showed significant reduction (improvement) in TGA with the metronome. Those with weak ability did not and exhibited high variability in the TGA response to metronome. Moreover, individuals who worsened in TGA when walking to metronome had poorer beat production scores than those who did not change in TGA. However, no interaction between TGA improvement when walking to metronome and rhythm perception or production ability was found. While responsiveness of TGA to RAS did not significantly differ based on strength of rhythm abilities, these preliminary findings highlight rhythm ability as a potential consideration when treating post-stroke individuals with rhythm-based treatments.

A Music-Based Digital Therapeutic: Proof-of-Concept Automation of a Progressive and Individualized Rhythm-Based Walking Training Program After Stroke

BACKGROUND

The rhythm of music can entrain neurons in motor cortex by way of direct connections between auditory and motor brain regions.

OBJECTIVE

We sought to automate an individualized and progressive music-based, walking rehabilitation program using real-time sensor data in combination with decision algorithms.

METHODS

A music-based digital therapeutic was developed to maintain high sound quality while modulating, in real-time, the tempo (ie, beats per minute, or bpm) of music based on a user's ability to entrain to the tempo and progress to faster walking cadences in-sync with the progression of the tempo. Eleven individuals with chronic hemiparesis completed one automated 30-minute training visit. Seven returned for 2 additional visits. Safety, feasibility, and rehabilitative potential (ie, changes in walking speed relative to clinically meaningful change scores) were evaluated.

RESULTS

A single, fully automated training visit resulted in increased usual (∆ 0.085 ± 0.027 m/s, P = .011) and fast (∆ 0.093 ± 0.032 m/s, P = .016) walking speeds. The 7 participants who completed additional training visits increased their usual walking speed by 0.12 ± 0.03 m/s after only 3 days of training. Changes in walking speed were highly related to changes in walking cadence (R² > 0.70). No trips or falls were noted during training, all users reported that the device helped them walk faster, and 70% indicated that they would use it most or all of the time at home.

CONCLUSIONS

In this proof-of-concept study, we show that a sensor-automated, progressive, and individualized rhythmic locomotor training program can be implemented safely and effectively to train walking speed after stroke. Music-based digital therapeutics have the potential to facilitate salient, community-based rehabilitation.

The correlation between rhythm perception and gait characteristics at different rhythms among children with cerebral palsy and typically developing children

BACKGROUND

It has been shown that motor training while listening to constant rhythm, is associated with coupling between movement and rhythm. To gain a better understanding of how rhythm perception may affect gait in children with cerebral palsy (CP) it seems important first to assess rhythm perception (RP) in these children.

RESEARCH QUESTION

To describe and compare RP and step characteristics in children with CP and typically-developing (TD) children, and to assess the impact of RP on step characteristics during different rhythms.

METHODS

The study included 24 children with CP, Gross Motor Function Classification System (GMFCS) levels I-II, age 7-12 years, who walk without assistive device, and 24 TD children matched for age and gender. RP was assessed by the perceptual beat alignment test (BAT). Gait parameters were recorded using a pressure-sensitive mat - the Gaitrite® system. Each participant walked on the mat at a comfortable walking pace and with the metronome set at 92.5 %, 100 % and 107.5 % of his preferred walking rhythm.

RESULTS

No significant difference in RP was noted between groups. Children with CP presented significantly larger step time and length variability. In TD children, those with better RP walked significantly slower, with lower step variability as compared to TD children with lower RP. Children in both groups, regardless of rhythm perception, successfully matched their cadence to the metronome's pace, both at the lower and higher rhythm, except TD children with lower rhythm perception, who failed to reduce their cadence sufficiently in the 92.5 % pace. Children with better RP in both groups changed more parameters in gait in response to rhythm changes.

SIGNIFICANCE

Assessing RP may predict which parameters of gait are expected to change when employing a metronome during child's walk.

Finger tapping as a proxy for gait: Similar effects on movement variability during external and self-generated cueing in people with Parkinson's disease and healthy older adults

BACKGROUND

Rhythmic auditory cueing has been widely studied for gait rehabilitation in Parkinson's disease (PD). Our research group previously showed that externally generated cues (i.e., music) increased gait variability measures from uncued gait, whereas self-generated cues (i.e., mental singing) did not. These different effects may be due to differences in underlying neural mechanisms that could be discerned via neuroimaging; however, movement types that can be studied with neuroimaging are limited.

OBJECTIVE

The primary aim of the present study was to investigate the effects of different cue types on gait, finger tapping, and foot tapping, to determine whether tapping can be used as a surrogate for gait in future neuroimaging studies. The secondary aim of this study was to investigate whether rhythm skills or auditory imagery abilities are associated with responses to these different cue types.

METHODS

In this cross-sectional study, controls (n=24) and individuals with PD (n=33) performed gait, finger tapping, and foot tapping at their preferred pace (UNCUED) and to externally generated (MUSIC) and self-generated (MENTAL) cues. Spatiotemporal parameters of gait and temporal parameters of finger tapping and foot tapping were collected. The Beat Alignment Task (BAT) and Bucknell Auditory Imagery Scale (BAIS) were also administered.

RESULTS

The MUSIC cues elicited higher movement variability than did MENTAL cues across all movements. The MUSIC cues also elicited higher movement variability than the UNCUED condition for gait and finger tapping.

CONCLUSIONS

This study shows that different cue types affect gait and finger tapping similarly. Finger tapping may be an adequate proxy for gait in studying the underlying neural mechanisms of these cue types.

Cadence Modulation in Walking and Running: Pacing Steps or Strides?

A change in cadence during walking or running might be indicated for a variety of reasons, among which mobility improvement and injury prevention. In a within-subject study design, we examined whether walking or running cadences are modulated best by means of step-based or stride-based auditory pacing. Sixteen experienced runners walked and ran on a treadmill while synchronizing with step-based and stride-based pacing at slow, preferred and fast pacing frequencies in synchronization-perturbation and synchronization-continuation conditions. We quantified the variability of the relative phase between pacing cues and footfalls and the responses to perturbations in the pacing signal as measures of coordinative stability; the more stable the auditory-motor coordination, the stronger the modulating effect of pacing. Furthermore, we quantified the deviation from the prescribed cadence after removal of the pacing signal as a measure of internalization of this cadence. Synchronization was achieved less often in running, especially at slow pacing frequencies. If synchronization was achieved, coordinative stability was similar, and the paced cadence was well internalized for preferred and fast pacing frequencies. Step-based pacing led to more stable auditory-motor coordination than stride-based pacing in both walking and running. We therefore concluded that step-based auditory pacing deserves preference as a means to modulate cadence in walking and running.

Music Therapy and Music-Based Interventions for Movement Disorders

PURPOSE OF REVIEW

There is emerging evidence that music therapy and other methods using music and rhythm may meaningfully improve a broad range of symptoms in neurological and non-neurological disorders. This review highlights the findings of recent studies utilizing music and rhythm-based interventions for gait impairment, other motor symptoms, and non-motor symptoms in Parkinson disease (PD) and other movement disorders. Limitations of current studies as well as future research directions are discussed.

RECENT FINDINGS

Multiple studies have demonstrated short-term benefits of rhythmic auditory stimulation on gait parameters including gait freezing in PD, with recent studies indicating that it may reduce falls. Demonstration of benefits for gait in both dopaminergic "on" and "off" states suggests that this intervention can be a valuable addition to the current armamentarium of PD therapies. There is also emerging evidence of motor and non-motor benefits from group dancing, singing, and instrumental music performance in PD. Preliminary evidence for music therapy and music-based interventions in movement disorders other than PD (such as Huntington disease, Tourette syndrome, and progressive supranuclear palsy) is limited but promising. Music therapy and other music and rhythm-based interventions may offer a range of symptomatic benefits to patients with PD and other movement disorders. Studies investigating the potential mechanisms of music's effects and well-controlled multicenter trials of these interventions are urgently needed.