Baseline Cadence Research Articles

Effects of increasing walking cadence on gait biomechanics in adults with knee osteoarthritis

Gait retraining is a strategy to manage altered loading patterns and pain characteristic of knee osteoarthritis. Lower walking cadence is associated with higher knee joint loading, vertical ground reaction forces, and risk for cartilage worsening. Therefore, we determined the acute effects of increasing walking cadence on measures of lower extremity loading and knee pain in knee osteoarthritis. Twenty-five participants with knee osteoarthritis (age = 62.5 ± 7.2; 76.0 % female) walked at fixed speed on an instrumented treadmill from which baseline cadence was measured. Five, randomized experimental cadence conditions (2 %, 4 %, 6 %, 8 %, or 10 % over baseline cadence) were completed. Real-time auditory and visual feedback on cadence was provided while kinematics and ground reaction forces were sampled. Linear mixed effects models evaluated the effect of cadence on knee adduction and flexion moment peaks and impulses, impact loading metrics (vertical ground reaction force impact peak, vertical average and instantaneous loading rates), and knee pain. Increasing cadence by 2–10 % did not significantly change knee adduction moment peaks or impulse. Peak knee flexion moment increased by 3–32 % and knee flexion moment impulse reduced by 2–9 % with increases in cadence, but these results were not significant (peak knee flexion moment, p = 0.070; knee flexion moment impulse, p = 0.085). Increasing cadence significantly increased the vertical impact peak (p < 0.001), and the vertical average (p = 0.010), and instantaneous (p = 0.007) loading rates. Small increases in cadence at a fixed gait speed does not significantly change surrogate measures of knee joint loading or pain, but does increase measures of impact loading.

Impact of Rubin Observatory Cadence Choices on Supernovae Photometric Classification

The Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) will discover an unprecedented number of supernovae (SNe), making spectroscopic classification for all the events infeasible. LSST will thus rely on photometric classification, whose accuracy depends on the not-yet-finalized LSST observing strategy. In this work, we analyze the impact of cadence choices on classification performance using simulated multiband light curves. First, we simulate SNe with an LSST baseline cadence, a nonrolling cadence, and a presto-color cadence, which observes each sky location three times per night instead of twice. Each simulated data set includes a spectroscopically confirmed training set, which we augment to be representative of the test set as part of the classification pipeline. Then we use the photometric transient classification library snmachine to build classifiers. We find that the active region of the rolling cadence used in the baseline observing strategy yields a 25% improvement in classification performance relative to the background region. This improvement in performance in the actively rolling region is also associated with an increase of up to a factor of 2.7 in the number of cosmologically useful Type Ia SNe relative to the background region. However, adding a third visit per night as implemented in presto-color degrades classification performance due to more irregularly sampled light curves. Overall, our results establish desiderata on the observing cadence related to classification of full SNe light curves, which in turn impacts photometric SNe cosmology with LSST.

Variable Cadence Gait Training Outcomes Using Rhythmic Auditory Stimulation Embedded in Older Adults' Preferred Music.

Older adults must have the ability to walk at variable speeds/distances to meet community demands. This single group pre-post test study's purposes were to examine if actual cadences after 7 weeks of rhythmic auditory stimulation gait training matched target cadences, improved walking distance, duration, velocity, maximum cadence, balance, enjoyment, and/or changed spatial/temporal gait parameters. Fourteen female adults (72.6 ± 4.4years) participated in 14 sessions, while variable cadences were progressively introduced. Eleven older adult responders walked faster (3.8 steps/min) than one target cadence (-10% pace) while matching the target cadences for the other paces when walking with rhythmic auditory stimulation. Two nonresponders walked near their baseline cadence with little variability while one walked at faster cadences; all three did not appear to adjust to the beat of the music. After training, participants increased their walking distance, 90.8 ± 46.5m; t(1, 13) = -7.3; p ≤ .005, velocity, 0.36 ± 0.15m/s; t(1, 40) = -15.4; p < .001, and maximum cadence, 20.6 ± 9.1 steps/min; t(1, 40) = -14.6; p < .001; changes exceeded minimal clinically important differences. Twelve of 14 expressed enjoyment. Walk with rhythmic auditory stimulation training is a promising activity for older adults, which may translate to an individual's ability to adapt walking speeds to various community demands.

Rhythmic auditory cueing in atypical parkinsonism: A pilot study.

Rhythmic auditory cueing (RAC) can improve gait parameters in neurological disorders such as Parkinson's disease and stroke. However, there is a lack of research on the effects of RAC in patients with atypical parkinsonian disorders (APD). Using a smartphone metronome application, we aimed to investigate the immediate effects of RAC in patients with clinically diagnosed APD, namely Progressive Supranuclear Palsy (PSP-Richardson Syndrome and other variants, PSP-nonRS), Corticobasal Syndrome (CBS), Multiple System Atrophy (MSA), and Dementia with Lewy Bodies (DLB). A total of 46 APD participants (25 PSP, 9 CBS, 8 MSA and 4 DLB; age: mean = 70.17, standard deviation = 7.15) walked at their preferred pace for 2 min without any rhythmic auditory cueing (RAC). Participants then walked the same path for another 2 min with RAC set at a tempo 10% faster than the baseline cadence of each participant. After a 10-15-min break, participants walked the same path for another 2 min without RAC to observe for carryover effects. Gait parameters [cadence (steps/minute), gait velocity (meters/minute), and stride length (centimeters)] were collected at baseline, during RAC, and post-RAC. There was a significant improvement in cadence in all participants from baseline to during RAC and post-RAC (corrected p-values = 0.009 for both). Gait velocity also improved from baseline to during RAC and post-RAC in all participants, although this improvement was not significant after correcting for multiple comparisons. The changes in cadence and gait velocity were most pronounced in PSP. In addition, our exploratory analysis showed that the cadence in the suspected TAU group (PSP+CBS) showed a significant improvement from baseline to during RAC and post-RAC (corr. p-value = 0.004 for both). This pilot study using short-term RAC in APD patients demonstrated improvements in cadence and velocity. There is an urgent need for effective gait rehabilitation modalities for patients with APD, and rhythmic cueing can be a practical and useful intervention to improve their gait pattern.

Simulating the Eclipsing Binary Yields of the Rubin Observatory in the Galactic Field and Star Clusters

Abstract We present a study of the detection and recovery efficiency of the Rubin Observatory for detached eclipsing binaries (EBs) in the galactic field, globular clusters (GCs), and open clusters (OCs), with a focus on comparing two proposed observing strategies: a standard cadence (baseline) and a cadence that samples the galactic plane more evenly (colossus). We generate realistic input binary populations in all observing fields of the Rubin Observatory, simulate the expected observations in each filter, and attempt to characterize the EBs using these simulated observations. In our models, we predict that the baseline cadence will enable the Rubin Observatory to observe about three million EBs; our technique could recover and characterize nearly one million of these in the field and thousands within star clusters. If the colossus cadence is used, the number of recovered EBs would increase by an overall factor of about 1.7 in the field and in globular clusters, and a factor of about 3 in open clusters. Including semidetached and contact systems could increase the number of recovered EBs by an additional factor of about 2.5 to 3. Regardless of the cadence, observations from the Rubin Observatory could reveal statistically significant physical distinctions between the distributions of EB orbital elements between the field, GCs, and OCs. Simulations such as these can be used to bias correct the sample of Rubin Observatory EBs to study the intrinsic properties of the full binary populations in the field and star clusters.

Current Evidence for Rhythmic Cueing and its Effects on Walking Ability in Individuals With Parkinson's Disease

<h3>Objective(s)</h3> To summarize the current evidence of rhythmic cueing (RC) and its effects on walking in Parkinson's disease (PD) to help guide clinicians in clinical application. <h3>Data Sources</h3> PubMed and GoogleScholar were searched using "Parkinson's Disease", "cueing", and "movement" MeSH terms. The search was filtered to include full-text articles from the last 10 years and to exclude articles not in English or done in animals. <h3>Study Selection</h3> Inclusion criteria: idiopathic PD; investigated the effects of RC on walking, and described type and application of RC. Two researchers independently screened and extracted data, a third researcher was used for consensus. Initial search identified 371 articles, and 44 were included after full-text review. <h3>Data Extraction</h3> A data extraction table was used and once completed, was further categorized by type of RC (auditory only, visual only, tactile only, comparative). <h3>Data Synthesis</h3> All but 3/44 included studies reported improvements in spatiotemporal parameters and freezing of gait. Positive results were seen acrossed types of RC but primarily demonstrated when integrated into a weekly gait training or exercise program over time; cue rates set between -80% to +25% of a participant's baseline cadence, and when RC was salient to participants. <h3>Conclusions</h3> Cueing provides a well-established technique as an adaptive strategy that has been shown to improve freezing and spatiotemporal parameters of gait in PD when implemented through a variety of methods and types that should be individualized. Despite the reported effectiveness of RC found within this review, future studies should explore characteristics training dosage, transferability, and responsiveness based on one's learning style. <h3>Author(s) Disclosures</h3> No conflicts to declare

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.

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

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

Influence Of A Novel Music App On Spatiotemporal Mechanics During Running

An increased running step rate (i.e., cadence) can decrease lower extremity joint loads and potentially reduce running-related injury (RRI) risk. Many gait interventions have significantly increased a runner’s cadence through a variety of external stimuli (e.g., metronome). Runners have been shown to spontaneously manipulate their cadence when listening to music with a tempo that differed ±3% from their baseline cadence. However, no study has determined whether a runner will subconsciously increase cadence > 3% when listening to up-tempo music. PURPOSE: To determine if music tempo (beats per minute, bpm) set 10% higher than baseline cadence affects spatiotemporal running mechanics. METHODS: Utilizing a blinded experimental design, twenty-two runners (15F, 7M, 18-40 yo) were recruited, granted informed consent, were randomly assigned to a control (C) or experimental (E) group, and picked four motivational songs. The Brunel Music Rating Inventory was used to rate song motivational level. Subjects ran three 5-min trials (5/10 effort) on a pressure-sensitive treadmill (Noraxon U.S.A., 100 Hz) with vertical ground reaction force and pressure recorded during the last 45 sec and lowpass filtered (40 Hz). Five-min of rest was given between trials. During the second trial, subjects listened to music via headphones with the bpm set to baseline cadence (C) or 10% higher (E). Music was administered via a novel smartphone application that permitted song tempo to be adjusted and maintained in one bpm increments. The last trial was completed without music with velocity held constant across all trials. A mixed design analysis of variance was run in JASP with a significance set apriori at 0.05. RESULTS: Baseline cadence was not significantly different between groups (C: 165.4±9.5 steps per minute, E 167.2±6.8, p=0.61). There was not a significant main effect (p=0.54, p=0.32, p=0.152, p=0.70) of music tempo between groups for cadence (F (1,20)=0.39), step width (F(1,20)=1.02), stance phase (F (1,20)=2.22), or foot rotation (F(1,20)=0.16). CONCLUSION: Spatiotemporal running mechanics do not spontaneously adjust when runners listen to motivational music set at a tempo 10% greater than baseline cadence. Listening to up-tempo music should not be considered an effective external stimulus to promote increased running cadence.

The effects of metronome frequency differentially affects gait on a treadmill and overground in people with Parkinson disease

BackgroundTreadmills and rhythmic auditory cueing can influence stepping rhythm for individuals with Parkinson disease (PD). Of concern, however, is that auditory cueing directly addresses the temporal features of gait, whereas adjusting step length may be more important for people with PD. Stepping to a faster cadence when walking overground may increase gait speed, but without requiring an increased step length. Furthermore, given the potentially valuable role of walking on a treadmill for individuals with PD, we are concerned that increasing cadence with rhythmic auditory cueing while walking at a constant treadmill speed will induce even shorter steps. Research questionWhat is the effect of different metronome cue frequencies on spatiotemporal gait parameters when walking overground compared to walking on a treadmill in people with PD? MethodsUsing a repeated-measures design, 21 people with PD (stage 1–3) walked overground and on a treadmill with and without metronome cues of 85 %, 100 %, and 115 % of their baseline cadence frequency for one minute each. We assessed step length, and cadence during all conditions. Gait speed was assessed during overground gait. ResultsAn interaction effect between cue frequency and walking environment revealed that participants took longer steps during the 85 % condition on the treadmill only. When walking overground, metronome cues of 85 % and 115 % of baseline cadence yielded decreases and increases, respectively, in both cadence and gait speed with no associated change in step length. SignificanceThese data suggest that people with PD are able to alter spatiotemporal gait parameters immediately when provided the appropriate metronome cue and walking environment. We propose to target shortened step lengths by stepping to the beat of slow frequency auditory cues while walking on a treadmill, whereas the use of fast frequency cues during overground walking can facilitate faster walking speeds.

On the Detectability of Planet X with LSST

Abstract Two planetary mass objects in the far outer solar system—collectively referred to here as Planet X— have recently been hypothesized to explain the orbital distribution of distant Kuiper Belt Objects. Neither planet is thought to be exceptionally faint, but the sky locations of these putative planets are poorly constrained. Therefore, a wide area survey is needed to detect these possible planets. The Large Synoptic Survey Telescope (LSST) will carry out an unbiased, large area (around 18000 deg2), deep (limiting magnitude of individual frames of 24.5) survey (the “wide-fast-deep (WFD)” survey) of the southern sky beginning in 2022, and it will therefore be an important tool in searching for these hypothesized planets. Here, we explore the effectiveness of LSST as a search platform for these possible planets. Assuming the current baseline cadence (which includes the WFD survey plus additional coverage), we estimate that LSST will confidently detect or rule out the existence of Planet X in 61% of the entire sky. At orbital distances up to ∼75 au, Planet X could simply be found in the normal nightly moving object processing; at larger distances, it will require custom data processing. We also discuss the implications of a nondetection of Planet X in LSST data.

Musical stimulation with feedback in gait training for Parkinson’s disease.

Patients suffering from idiopathic Parkinson's disease (PD) are unable to steadily generate regular steps due to an impairment of the basal ganglia that do not cue the supplementary motor area properly (Iansek, Bradshaw, Phillips, Cunnington, & Morris, 1995). This results in the main hallmarks of parkinsonian gait: reduced step cadence, reduced velocity, and shortened stride length. In the 1990s the use of acoustic stimulation for the rehabilitation of gait disorders in PD was developed under the concept of rhythmic auditory stimulation (RAS). RAS consists of a clear accentuated, either metronomic or musical rhythm that stimulates the production of rhythmical movements (Thaut, 2005), especially with respect to their timing. The consistent coupling between steady tempo of the acoustic stimulation (bpm, beats per minute) and walking cadence (spm, steps per minute) of PD patients has This been systematically investigated and the effectiveness of RAS broadly attested (for reviews see Lim et al., 2005; Nombela, Hughes, Owen, & Grahn, 2013; Tomlinson et al., 2013).In the standard RAS protocol, stimulation tempo usually corresponds to baseline cadence increased by 10% (Arias & Cudeiro, 2008; Freedland et al., 2002; Hausdorff, Lownthal, Herman, Gruendlinger, Peretz, & Giladi, 2007; Willems et al., 2006). RAS exerts a direct effect upon cadence and a consequent effect upon stride length. Because stride length in PD patients is lower than in healthy people at any given velocity (Ebersbach et al., 1999), it may be beneficial for the patient to address it specifically, as an independent therapy goal.Our choice of using musical instead of metronomic stimuli follows music therapist Michael Thaut's approach, where rhythmic stimuli are embedded in a musical structure. The approach is based on findings that rhythmic patterns within a musical context reduce response variability and synchronization offset more effectively than do single-pulse pattern in the frequency range of 60 to 120 spm (Thaut et al., 1996). Moreover, it has been demonstrated that healthy subjects synchronize more precisely (i.e., with lower negative mean asynchrony) with musical rather than metronomic stimuli (Repp, 2005). In the early studies with PD patients, RAS consisted of instrumental pieces in 2/4 or 4/4 m with rhythmic on-beats enhanced by a metronome (McIntosh, Brown, Rice, & Thaut, 1997; Miller, Thaut, McIntosh, & Rice, 1996; Thaut et al., 1996), and it was suggested that, compared with metronome, musical texture provides additional timing information and may therefore facilitate detection, anticipation, and synchronization to the beat (Thaut, Rathbun, & Miller, 1997). Moreover, music facilitates emotional involvement and motivates engagement in a task, and might therefore be a more efficient stimulation than the plain metronome beat. Recently, attention to the comparison between metronomic and musical stimulation and to the specific features that would account for the effectiveness of music seems to be increasing (Buhmann, Desmet, Moens, Van Dyck, & Leman, 2016; Styns, van Noorden, Moelants, & Leman, 2007; Wittwer, Webster, & Hill, 2013). Moreover, the specific effectiveness of music-based movement therapy on PD has been investigated in a meta-analysis (de Dreu, van der Wilk, Poppe, Kwakkel, & van Wegen, 2012).The fundamental advantage of the RAS approach is that it is able to replace the impaired internal stimuli of a parkinsonian brain. However, as stimulation proceeds independently from movement execution, there is no feedback mechanism that helps evaluate movements' adequacy. The potential of concurrent sensory feedback for enhancing motor learning has been extensively studied on healthy subjects (Sigrist, Rauter, Riener, & Wolf, 2013) and an interactive, feedback-like version of RAS has been recently proposed for the training of stride time in PD patients (Hove1, Suzuki, Uchitomi, Orimo, & Miyake, 2012). …

MODELING THE PERFORMANCE OF THE LSST IN SURVEYING THE NEAR-EARTH OBJECT POPULATION

ABSTRACT We have performed a detailed survey simulation of the LSST performance with regards to near-Earth objects (NEOs) using the project’s current baseline cadence. The survey shows that if the project is able to reliably generate linked sets of positions and times (a so-called “tracklet”) using two detections of a given object per night and can link these tracklets into a track with a minimum of three tracklets covering more than a ∼12 day length-of-arc, then they would be able to discover 62% of the potentially hazardous asteroids (PHAs) larger than 140 m in its projected 10 year survey lifetime. This completeness would be reduced to 58% if the project is unable to implement a pipeline using the two detection cadence and has to adopt the four detection cadence more commonly used by existing NEO surveys. When including the estimated performance from the current operating surveys, assuming these would continue running until the start of LSST and perhaps beyond, the completeness fraction for PHAs larger than 140 m would be 73% for the baseline cadence and 71% for the four detection cadence. This result is a lower completeness than the estimate of Ivezić et al.; however, the result is quite close to that of Jones et al., who show ∼70% completeness using the identical survey cadence as used here. We show that the traditional method of using absolute magnitude H &lt; 22 mag as a proxy for the population with diameters larger than 140 m results in completeness values that are too high by ∼5%. Our simulation makes use of the most recent models of the physical and orbital properties of the NEO and PHA populations, as well as simulated cadences and telescope performance estimates provided by the LSST project. The consistency of the results presented here when compared to those of Jones et al. demonstrates the robustness of these survey modeling approaches. We also show that while neither LSST nor a space-based IR platform like NEOCam individually can complete the survey for 140 m diameter NEOs, the combination of these systems can achieve that goal after a decade of observation.

Virtual Reality and Musculoskeletal Pain: Manipulating Sensory Cues to Improve Motor Performance During Walking

Musculoskeletal pain (MSP) is the most expensive nonmalignant health problem and the most common reason for activity limitation. Treatment approaches to improve movement without aggravating pain are urgently needed. Virtual reality (VR) can decrease acute pain, as well as influence movement speed. It is not clear whether VR can improve movement speed in individuals with MSP without aggravating pain. This study investigated the extent to which different audio and optic flow cues in a VR environment influenced walking speed in people with and without MSP. A total of 36 subjects participated, 19 with MSP and 17 controls. All walked on a motorized self-paced treadmill interfaced with a three-dimensional virtual walkway. The audio tempo was scaled (75%, 100%, and 125%) from baseline cadence, and optic flow was either absent, or scaled to 50% or 100% of preferred walking speed. Gait speed was measured during each condition, and pain was measured before and after the experiment. Repeated measures analysis of variance showed that audio tempo above baseline cadence significantly increased walking speed in both groups, F(3, 99)=10.41, p<0.001. Walking speed increases of more than 25% occurred in both groups in the 125% audio tempo condition, without any significant increase in pain. There was also a trend toward increased walking speeds with the use of optic flow, but the results in this study did not achieve significance at the p<0.05 level, F(2, 66)=2.01, p=0.14. Further research is needed to establish the generalizability of increasing movement speed across different physical performance tasks in VR.

The effects of pulsed auditory stimulation on various gait measurements in persons with Parkinson's Disease

The purpose of this study was to examine the Functional Ambulation Performance Score (FAP; a quantitative gait measure) in persons with Parkinson's Disease (PD) using the auditory stimulation of a metronome (ASM). Participants (n = 16; 5F/11M; range 60--84 yrs.) had a primary diagnosis of PD and were all independent ambulators. Footfall data were collected while participants walked multiple times on an electronic walkway under the following conditions: 1) PRETEST: establishing baseline cadence, 2) ASM: metronome set to baseline cadence, 3) 10ASM: metronome set to 10% FAP scores increased between PRETEST and POSTTEST. PRE/POSTTEST comparisons also indicated decreases in cycle time and double support and increases in step length and step-extremity ratio (step length/leg length). The results confirm prior findings that auditory stimulation can be used to positively influence the gait of persons with PD and suggest beneficial effects of ASM as an adjunct to dopaminergic therapy to treat gait dysfunctions in PD.

Velocity modulation and rhythmic synchronization of gait in Huntington's disease.

This study analyzed the ability of patients with Huntington's disease (HD) to modulate gait velocity without external sensory cues and in response to an auditory rhythmic cue within a frequency entrainment design. Uncued gait patterns of 27 patients were first assessed during normal, slower, and faster self-paced walking. During rhythmic trials, metronome and musical beat patterns were delivered at rates 10% slower and 10-20% faster than baseline cadence to cue gait patterns. After the rhythmic trials, patients were retested at normal gait speed without rhythm. Gait velocities in the patients with HD were below normal reference values in all ranges. Patients were able to significantly (p <0.05) modulate their gait velocity during self-paced and rhythmic metronome cueing but not during music. The ability to modulate gait velocity was retained regardless of the severity of the disease. Gait velocity declined with an increase in disability and chorea score. The disability score differentiated better between gait velocity of moderately and severe patients than chorea score. Slowness of gait was significantly correlated only with disability score and not with chorea. Patients had more difficulty producing adequate step rates than stride lengths during normal and fast walking speeds. After the rhythmic trials, unpaced gait velocity remained significantly (p <0.05) higher than baseline. This carry-over effect was not seen after the uncued trials. Synchronization ability was deficient in all patients, deteriorated with severity of disease, and was already compromised in patients with soft disease signs. Rhythmic tracking of music declined more with severity of disease than metronome tracking. In summary, patients were able to modulate velocity with and without external cues. Velocity adaptations to the external rhythm in music and metronome were achieved without exact synchronization between step cadence and rhythmic stimulus.

Rhythmic Auditory Stimulation in Gait Training for Patients with Traumatic Brain Injury.

Rhythmic auditory stimulation (RAS) was studied in a frequency entrainment design and as a therapeutic stimulus to facilitate gait patterns in 8 traumatically brain injured individuals (5 male/3 female; mean age 30 +/- 5 years) with persisting gait disorder, 4-24 months postinjury. During entrainment, with RAS frequency matched to baseline cadence, velocity and stride symmetry both increased by an average of 18%. Increases contributing to the velocity improvement were seen in both stride length (7%) and cadence (8%). With RAS accelerated 5% over the fast walking step rate of the patients, 5 patients could entrain to a higher step frequency. The 2 patients with the slowest baseline gait velocity could not entrain to faster RAS frequencies. After 5 weeks of daily RAS training, 5 patients' mean velocity increased significantly (p </=.05) by 51% (38.8 m/min to 57.6 m/min; p </=.43). Cadence (+16%) and stride length (+29%) also showed statistically significant improvement. Stride symmetry improved nonsignificantly by 12%.

Rhythmic auditory-motor facilitation of gait patterns in patients with Parkinson's disease.

OBJECTIVES: The effect of rhythmic auditory stimulation (RAS) on gait velocity, cadence, stride length, and symmetry was studied in 31 patients with idiopathic Parkinson's disease, 21 of them on (ON)...