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Background: Micrographia, or small handwriting, is a common symptom of Parkinson's disease (PD). Weighted pens have previously been recommended to improve handwriting, but there is limited research supporting their effectiveness. Additionally, previous research has demonstrated that music as an auditory cue can reduce variability in fine motor movements, but its effect on handwriting in people with PD remains unknown., Purpose: This study explored potential handwriting interventions for people with PD by evaluating the effectiveness of weighted pens and auditory cues on handwriting., Study Design: This was a pilot cohort study., Methods: Eight older adults with PD used a standard pen and a weighted pen to write continuous cursive "l"s on 1.5-cm-lined paper for a total of 10 seconds while listening to auditory cues in 4 conditions: control (silence), metronome, activating music, and relaxing music. Kinematic data were measured with sensors attached to the tip of each pen, and muscle activity was measured with electromyography sensors adhered to the extensor digitorum communis and first dorsal interosseous., Results: When writing with the standard pen, peak-to-peak time was reduced in the metronome (control = 0.807 ± 0.121 seconds, metronome = 0.701 ± 0.100 seconds, p = 0.024) and activating (control = 0.807 ± 0.121 seconds, activating = 0.691 ± 0.113 seconds, p = 0.009) conditions compared to the control condition. Furthermore, the weighted pen increased the variability of distance between letter peaks (standard = 0.187 ± 0.010, weighted = 0.482 ± 0.065, p = 0.033) and the variability of time needed to complete each letter (standard = 0.176 ± 0.010, weighted = 0.187 ± 0.016, p = 0.042) compared to the standard pen. Finally, area under the curve of the extensor digitorum communis was reduced in the metronome (metronome = 66.03 ± 25.74 mV, control = 88.98 ± 30.40 mV, p = 0.034) and activating music (activating = 66.49 ± 26.02 mV, control = 88.98 ± 30.40 mV, p = 0.012) conditions compared to control when writing with the standard pen., Conclusions: These results suggest that weighted pens may not improve handwriting in novice users, but auditory cues appear beneficial. This can inform future directions in the research and clinical application of handwriting interventions for persons with PD., Competing Interests: Declaration of Competing Interest The authors declare no competing financial interests., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Introduction: Older adults experience a decline in motor inhibition. These declines have been implicated in instrumental activities of daily living. However, studies have revealed that older musicians have behavioral and neurophysiological enhancements in various motor domains compared to non-musicians. This suggests that music training may delay the decline in motor inhibition with aging. Nevertheless, motor inhibition has not been studied in young or older musicians and non-musicians. Thus, the present study aimed to investigate the neurophysiological differences in motor inhibition in aging musicians and non-musicians., Methods: A total of 19 healthy young adult musicians, 16 healthy young non-musicians, 13 healthy older adult musicians, and 16 healthy older adult non-musicians were recruited for the study. Transcranial magnetic stimulation single-pulse (SP) and short interval cortical inhibition (SICI) were performed at rest and then converted into inhibition percentage., Results: We did not observe significant differences between young and older musicians and non-musicians in resting SP MEP. Older adults had lower resting SICI MEP than young adults. Older adults (36%) had a greater percentage of inhibition than young adults (16%). However, when controlling for background EMG activity, musicians had a lower inhibition percentage than non-musicians., Discussion: The results revealed that, despite the greater use of spinal mechanisms, decreased SICI, and increased inhibition percentage in older adults, motor inhibitory circuitry remains intact and functional in both young and older musicians and non-musicians. Future studies will reveal whether there are differences in motor inhibition during movement in musicians across a person's lifespan., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Izbicki, Mendoza, Zaman and Stegemöller.)

Introduction: Much research has examined the relationship between bradykinesia and gait impairment in persons with Parkinson's disease (PD). Specifically, impairments in repetitive movements of the upper extremity have been associated with freezing of gait. Studies examining lower extremity repetitive movements are limited. Moreover, the use of external cueing has been a treatment strategy for both bradykinesia and gait, but information on how cues should be used is lacking. The purpose of this study was to compare the effects of auditory cueing on one side versus both sides for bilateral repetitive toe tapping and gait, and to determine if there was a relationship between toe tapping and gait. We hypothesize that there will be no difference between the cueing conditions, but that there will be a significant association between repetitive toe tapping performance and gait performance., Methods: Twenty-seven persons with PD completed a toe tapping task in which the more affected side was cued at 70 beats per minute (BPM), the less affected side was cued at 70 BPM, and both sides were cued at 140 BPM. The same cueing conditions were completed for the gait task. Inter movement interval and amplitude data was collected and analyzed for the toe tapping task. Stance time, swing time, step length, and step width were collected and analyzed for the gait task., Results: Results revealed a significant difference in movement performance between the single side cueing conditions and both sides cued condition for inter movement interval (toe tapping), stance time (gait), step length (gait), and step width (gait). Moreover, results revealed a significant association between inter movement interval and stance time and step length., Discussion: These results would suggest that cueing both sides is better than only one side and that there is a relationship between toe tapping and gait performance when both sides are cued in persons with PD. This study adds to the literature exploring possible shared mechanisms between bradykinesia and gait in persons with PD., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Stegemöller, Berg, Warnecke and Hammer.)

Background: Many of the motor symptoms of Parkinson's disease (PD) impact quality of life and are not fully ameliorated by current pharmacological and surgical treatments. A better understanding of the pathophysiology underlying these symptoms is needed. Previous research has suggested that inflammation may play a significant role in PD pathophysiology and progression, but there is limited research exploring how inflammation directly relates to motor symptoms in PD. Thus, the purpose of this study was to evaluate associations between peripheral immune inflammatory markers and motor symptoms of PD, specifically, tremor, bradykinesia, and postural and gait instability. We hypothesized that peripheral inflammatory cytokines would predict the severity of motor symptoms in persons with PD, and that there will be higher levels of peripheral inflammatory cytokine markers in persons with PD when compared to age-matched healthy older adults., Methods: Twenty-six participants with PD and fourteen healthy older adults completed the study. For participants with PD, the motor section of the Unified Parkinson's Disease Rating Scale (UPDRS) was recorded and scored by two Movement Disorders Neurologists masked to the study. A blood sample was collected from both participants with PD and the healthy older adults. Through the MILLIPLEX® map High Sensitivity Human Cytokine Kit, key inflammation-related markers were analyzed (TNF- α , IFN-γ, IL-1β, IL-8, IL-2, IL-7, IL-5, IL-13, IL, 4, IL-10 IL-12p70, GM-CSF, and IL-6)., Results: Results revealed significantly higher levels of IL-6 in persons with PD when compared to healthy older adults ( p  ​= ​0.005). Moreover, results revealed that higher levels of IL-4 ( p  ​= ​0.011) and lower levels of IFNγ ( p  ​= ​0.003) significantly predicted more severe tremor in persons with PD. No other associations between the peripheral inflammation markers and other motor symptoms were observed., Conclusions: Overall, these results are consistent with a growing body of literature that implicates inflammatory cytokines in the PD, and further suggests that inflammatory cytokines, or lack thereof, may be associated with tremor in persons with PD., (© 2022 The Authors.)

Music has been a therapeutic strategy proposed to improve impaired movement performance, but there remains a lack of understanding of how music impacts motor cortical activity. Thus, the purpose of this study is to use a time-frequency analysis (i.e., wavelet) of electroencephalographic (EEG) data to determine differences in motor and auditory cortical activity when moving to music at two different rates. Twenty healthy young adults tapped their index finger while electroencephalography was collected. There were three conditions (tapping in time with a tone and with two contrasting music styles), and each condition was repeated at two different rates (70 and 140 beats per minute). A time-frequency Morlet wavelet analysis was completed for electrodes of interest over the sensorimotor areas (FC3, FC4, FCz, C3, C4, Cz) and the primary auditory areas (T7, T8). Cluster-based permutation testing was applied to the electrodes of interest for all conditions. Results showed few differences between cortical oscillations when moving to music versus a tone. However, the two music conditions elicited a variety of distinct responses, particularly at the slower movement rate. These results suggest that music style and movement rate should be considered when designing therapeutic applications that include music to target motor performance., (© 2021 The Authors. Brain and Behavior published by Wiley Periodicals LLC.)

The inclusion of music into the treatment plan for persons with Parkinson's disease (PD) may be a viable strategy to target multiple motor symptoms. However, potential mechanisms to explain why music has an impact on multiple motor symptoms in persons with PD remain understudied. The purpose of this study was to examine the acute effects of 1 h of group therapeutic singing (GTS) on physiological measures of stress and clinical motor symptoms in persons with PD. We posit that improvement in motor symptoms after GTS may be related to stress reduction. Seventeen participants with PD completed 1 h of GTS and eight participants completed 1 h of a quiet reading (control session). Cortisol was collected via passive drool immediately before and after the singing and control session. The Unified Parkinson's Disease Rating Scale (UPDRS) Part-III (motor examination) was also video-recorded immediately before and after the singing and control session and scored by two raters masked to time and condition. Secondary outcome measures for quality of life, depression, and mood were collected. Results revealed no significant change in cortisol or motor UPDRS scores, as well as no significant relationship between cortisol and motor UPDRS scores. There was a trend for the singing group to report feeling less sad compared to the control group after the 1-h session (effect size = 0.86), and heart rate increased in the singing group while heart rate decreased in the control group after the 1-h session. These results suggest that an acute session of GTS is not unduly stressful and promotes the use of GTS for persons with PD. Multiple mechanisms may underlie the benefits of GTS for persons with PD. Further exploring potential mechanisms by which singing improves motor symptoms in persons with PD will provide greater insight on the therapeutic use of music for persons with PD., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Stegemöller, Zaman, Shelley, Patel, Kouzi and Shirtcliff.)

The first-year student experience in college is a crucial time for personal and professional development, especially for students entering science, technology, education, and mathematics (STEM) disciplines. Unfortunately, it is also the time when students most commonly leave STEM, largely due to disconnection from faculty and peers. The Freshman Research Initiative (FRI) is a program that introduces first-year undergraduates to research in a variety of fields. The program has shown positive outcomes for student success and retention in STEM fields. However, it has not been demonstrated whether this program can increase social connectedness and assurance, potentially contributing to students' longer-term retention in STEM. In this pilot study, we measured social connectedness/assurance among students before and after a 16-week course in neurophysiology. We found that combined scores of social connectedness and assurance significantly increased by the end of the course. We also found that individual constructs of social connectedness and assurance significantly increased. Furthermore, the majority of students from FRI were retained in STEM fields. We plan future studies to include collection of longitudinal data and measures to identify additional reasons that the FRI increased these positive outcomes among our student participants.

Background: Exercise shows promise for improving physical and cognitive functioning, quality of life, and mood in individuals with Parkinson's disease (PD). Structured interviews have suggested potential factors influencing participation in exercise in this population, but no studies have examined if they predict exercise behaviour., Methods: Thirty persons with PD completed the International Physical Activity Questionnaire and a semi-structured interview. Time spent exercising was calculated by summing responses for recreation, sport, and leisure-time physical activity. Predictors of exercise were assessed via interview. In addition, participants were asked about what types of exercise they engaged in and what types of exercise they would be interested in trying. Regression analyses were used to identify the factors that predicted time spent exercising, as well as determining factors in low vs. high exercisers (≥150 min per week)., Results: Positive predictors of exercise were being male ( β = -0.52, p  = 0.01; χ 2  = 4.84, p  = 0.03), married ( β  = 0.32, p  = 0.03; χ 2  = 5.60, p  = 0.02), and enjoyment of exercise ( β  = 0.36, p  = 0.02). Fear of falling ( β  = -0.41, p  = 0.01; χ 2  = 4.29, p  = 0.04), negative perception of health ( β  = -0.41, p  = 0.02), perception of PD symptoms ( χ 2  = 12.45, p  < 0.001), bad weather ( χ 2  = 5.06, p  = 0.02), and lack of an exercise partner ( χ 2  = 13.39, p  < 0.001) were negative predictors of exercise., Conclusions: Results from this study suggest that exercise programmes should work to make activities enjoyable, safe, and adaptable to the abilities of the individual. Programmes should also include social engagement.Implications for rehabilitationParkinson's exercise programmes should be enjoyable.Parkinson's exercise programmes should include both social engagement and social support.Parkinson's exercise programmes should be safe and adaptable to the abilities of the participants.Parkinson's exercise programmes should aim to improve balance and reduce fear of falling.Individual exercise programmes can also be successful, many people with PD exercise alone with the most common form being walking.

Studies have reported that Parkinson's disease (PD) is associated with impairments on cognitive visual tasks. However, the effects of dopamine on cognitive vision remain equivocal. The purpose of this study was to examine performance on cognitive vision tasks in persons with PD and the effects of levodopa on these tasks. Fourteen individuals with PD and 14 age- and sex-matched healthy older adults completed the study. Participants with PD completed the visual tasks following a 12-h withdrawal of dopaminergic medication and again 1 h after taking 1.5 times their normal dose of levodopa. Healthy older adults completed the visual tasks twice using the same session format. Five complex visual tasks were completed, including line discrimination, object discrimination, facial discrimination, visual working memory, and object rotation. The Unified Parkinson's Disease Rating Scale was also collected off and on medication. Participants with PD performed significantly worse than the healthy older adults across all five visual tasks. There were no significant differences in performance between the off and on medication state in persons with PD. This finding indicates either that dopamine deficiency may not be responsible for cognitive visual impairments in PD or that cognitive visual impairments in PD might simply be the result of deficits in more basic visual processing., (Copyright © 2020 Anderson and Stegemöller.)

External cues, such as music, improve movement performance in persons with Parkinson's disease. However, research examining the motor cortical mechanisms by which this occurs is lacking. Research using electroencephalography in healthy young adults has revealed that moving to music can modulate motor cortical activity. Moreover, motor cortical activity is further influenced by music experience. It remains unknown whether these effects extend to corticomotor excitability. Therefore, the primary aim of this study was to determine the effects of novel music on corticomotor excitability using transcranial magnetic stimulation (TMS) in a pilot study of healthy young adults. A secondary aim of this study was to determine the influence of music experience on corticomotor excitability. We hypothesized that corticomotor excitability will change during music conditions, and that it will differ in those with formal music training. Motor evoked potentials (MEPs) were recorded from the first dorsal interosseous using single-pulse TMS in three conditions: (1) No Music, (2) Music Condition I, and (3) Music Condition II. Both pieces were set to novel MIDI piano instrumentation and part-writing conventions typical of early nineteenth-century Western classical practices. Results revealed Music Condition II (i.e., more relaxing music) compared to rest increased MEP amplitude (i.e., corticomotor excitability). Music Condition II as compared to Music Condition I (i.e., more activating music) reduced MEP variability (i.e., corticomotor variability). Finally, years of formal music training did not significantly influence corticomotor excitability while listening to music. Overall, results revealed that unfamiliar music modulates motor cortical excitability but is dependent upon the form of music and possibly music preference. These results will be used to inform planned studies in healthy older adults and people with Parkinson's disease., (Copyright © 2020 Izbicki, Zaman and Stegemöller.)

Introduction: Group therapeutic singing (GTS) may be an effective treatment for voice and respiratory impairments in persons with Parkinson's disease (PD). However, it remains unknown if GTS can be effectively delivered through telemedicine. Methods: Participants with PD from rural areas were recruited to complete a prerecorded GTS program, once a week for 8 weeks. Voice and respiratory outcome measures were collected 1 week before and 1 week after intervention. Results: Ten participants were enrolled in the study. One participant dropped at week 3. Five participants attended all eight sessions, two participants completed seven sessions, and one participant completed six sessions for 93.75% compliance. Statistical analysis for the data collected from the eight participants enrolled in the study revealed that voice outcome measures improved but did not reach significance. However, respiratory outcome measures significantly improved. Discussion: Results suggest that prerecorded GTS is feasible. Moreover, results are in keeping with results from a previous study using the exact same intervention with an in person therapist. Thus, this pilot work suggests that the use of prerecorded GTS may be a viable treatment option for those with limited access to care.

Little is known regarding how repetitive finger movement performance impacts other fine motor control tasks, such as circle drawing, in persons with Parkinson's disease (PD). Previous research has shown that impairments in repetitive finger movements emerge at rates near to and above 2 Hz in most persons with PD. Thus, the purpose of this study was to compare circle drawing performance in persons with PD that demonstrate impairment in repetitive finger movement and those that do not. Twenty-two participants with PD and twelve healthy older adults completed the study. Only participants with PD completed the repetitive finger movement task. From the kinematic data for the repetitive finger movement task, participants were grouped into Hasteners and Non-Hasteners. Participants with PD and the healthy older adults completed a series of circle drawing tasks at two different target sizes (1 cm and 2 cm) and three pacing conditions (Self-paced, 1.25 Hz, and 2.5 Hz). Kinematic and electromyography data were recorded and compared between groups. Results revealed that, in general, persons with PD demonstrate impairments in circle drawing and associated electromyography activity compared to healthy older adults. Moreover, persons with PD that hasten during repetitive finger movements demonstrate significantly increased movement rate during circle drawing, while those persons with PD that do not hasten demonstrate a significant increase in width variability. This suggests that differing motor control mechanisms may play a role in the performance of fine motor tasks in persons with PD. Continued research is needed to better understand differences in circle drawing performance among persons with PD to inform future development of patient-centered treatments., Competing Interests: The authors have declared that no competing interests exist.

Background. Sedentary behavior is a growing public health concern and may have particular relevance for the Parkinson disease (PD) population. However, the influence of sedentary time on factors associated with quality of life (QOL) in PD is unknown. The primary purpose of this study was to examine relationships between sedentary behaviors and markers of PD-specific QOL. A secondary purpose was to examine relationships between physical activity behaviors and QOL. Methods. We assessed sedentary and active behaviors using objective and interview measures and examined relationships between these behaviors and a measure of PD-specific QOL in individuals with PD. Results. Results demonstrated that sedentary time was significantly related to several aspects of QOL, including perceived deficits in the domains of mobility, cognitive processing, and communication. Additionally, results showed that time spent watching television was more strongly associated with lower levels of QOL than other more engaging sedentary activities. For physical activity, relationships between objective measures and QOL were weaker and only significantly associated with mobility. Time spent doing housework was associated with lower levels of QOL, whereas time spent in recreational activity was associated with lower levels of discomfort. Discussion. These results suggest that targeting decreases in sedentary behaviors (eg, reducing time spent watching television, breaking up prolonged bouts of sedentary time) may be effective for improving QOL in individuals with PD.

Background: Little is known regarding how repetitive finger movement performance, an assessment of bradykinesia (slowness of movement), is related to fine-motor dexterity tasks in people with Parkinson's disease (PD)., Objective: This pilot study examined the relationship between the performance of fine-motor dexterity tasks and repetitive finger movement in people with PD., Method: Forty-six participants with PD completed an acoustically cued repetitive finger movement task (1-3 Hz). Movement amplitude, movement rate difference, and coefficient of variation were obtained for each tone rate. Participants also completed a buttoning and Purdue pegboard assembly task. Buttoning time and number of assemblies were recorded., Results: A significant association was found between movement rate difference and movement rate difference coefficient of variation and buttoning performance in which higher movement rate and higher variability were associated with slower buttoning times. No significant associations between any of the repetitive finger movement outcome measures and Purdue pegboard assembly performance were revealed., Conclusion: Changes in movement amplitude and movement rate may influence fine-motor dexterity tasks differently. Thus, it is important to consider the quantitative assessment of both movement rate and movement amplitude because they may indicate differential clinical applications in the treatment of people with PD., (Copyright © 2019 by the American Occupational Therapy Association, Inc.)

Auditory cues, including music, are commonly used in the treatment of persons with Parkinson's disease. Yet, how music style and movement rate modulate movement performance in persons with Parkinson's disease have been neglected and remain limited in healthy young populations. The purpose of this study was to determine how music style and movement rate influence movement performance in healthy young adults. Healthy participants were asked to perform repetitive finger movements at two pacing rates (70 and 140 beats per minute) for the following conditions: (a) a tone only, (b) activating music, and (c) relaxing music. Electromyography, movement kinematics, and variability were collected. Results revealed that the provision of music, regardless of style, reduced amplitude variability at both pacing rates. Intermovement interval was longer, and acceleration variability was reduced during both music conditions at the lower pacing rate only. These results may prove beneficial for designing therapeutic interventions for persons with Parkinson's disease.

Although there is a growing interest in using music to improve movement performance in various populations, there remains a need to better understand how music influences motor cortical activity. Listening to music is tightly linked to neural processes within the motor cortex and can modulate motor cortical activity in healthy young adult (HYAs). There is limited evidence regarding how moving to music modulates motor cortical activity. Thus, the purpose of this study was to explore the influence of moving to music on motor cortical activity in HYAs. Electroencephalography was collected while 32 HYAs tapped their index finger in time with a tone and with two contrasting music styles. Two movement rates were presented for each condition. Power spectra were obtained from data collected over the primary sensorimotor region and supplemental motor area and were compared between conditions. Results revealed a significant difference between both music conditions and the tone only condition for both the regions. For both music styles, power was increased in the beta band for low movement rates and increased in the alpha band for high movement rates. A secondary analysis determining the effect of music experience on motor cortical activity revealed a significant difference between musicians and non-musicians. Power in the beta band was increased across all conditions. The results of this study provide the initial step towards a more complete understanding of the neurophysiological underpinnings of music on movement performance which may inform future studies and therapeutic strategies., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Repetitive finger movement significantly impacts daily living activities, but there have been limited studies determining how repetitive finger movement impacts quality of life (QOL) in persons with Parkinson's disease (PD). The purpose of this study was to determine the relationship between impairment in repetitive finger movement and QOL in persons with PD., Methods: Eighty-four participants with PD completed a repetitive movement task and the Parkinson's Disease Questionnaire (PDQ). Structural equation modeling was used to determine the relationship between repetitive finger movement outcome measures of amplitude and movement rate difference and the domains of the PDQ., Results: Including all repetitive finger outcome measures with demographic variables produced the strongest model for predicting QOL., Discussion: Repetitive finger movement is associated with QOL, but more research is needed to better understand the relationship between repetitive finger movement variables and each specific QOL domain.

Background: Parkinson's disease (PD) is a progressive neurodegenerative disorder that leads to altered neural control of movement, including the control of voice, respiration, and swallowing. There is a prevalent need to provide therapy for voice, respiration, and swallowing difficulties because current pharmacological and surgical treatments do not effectively treat these impairments. Previous research has demonstrated that singing may be a treatment option to target voice, respiratory, and swallowing impairments, as well as quality of life. However, participants' perspectives related to reasons for enrolling and engaging in programs as well as evaluation of singing programs have been neglected., Objective: The purpose of this descriptive study was thus to solicit participants' views of their involvement in a group singing intervention (GSI) led by credentialed music therapists., Methods: Twenty persons with PD were interviewed 4 to 6 months after completing the singing intervention. Participants were asked about 1) why they chose to participate, 2) what were the beneficial and non-beneficial aspects of participating, and 3) how to improve overall design and delivery of the GSI., Results: Using content analysis procedures, we learned that participants regarded their involvement in the study as mutually beneficial, fun, and engaging. Participants appreciated the fellowship with other persons with PD and offered minimal constructive criticism., Conclusions: This study provided greater insight into how a therapeutic singing program may benefit participants and positively impact their lives., (© American Music Therapy Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com)

Objective: For persons with Parkinson's disease (PD), secondary motor symptoms such as swallow impairment impact the quality of life and are major contributors to mortality. There is a present need for therapeutic interventions aimed at improving swallow function during the early stages of PD. The purpose of this pilot study was to examine the effects of a group therapeutic singing intervention on swallowing in persons with PD with no significant dysphagia symptoms., Design: Cohort study., Setting: University in the United States., Participants: Twenty-four participants with PD., Intervention: Eight weeks of group therapeutic singing., Main Outcome Measures: Electromyography (EMG) was used to assess muscle activity associated with swallow pre and post the group singing intervention. Swallow quality of life (SWAL-QOL) and the Unified Parkinson's Disease Rating Scale (UPDRS) were also obtained pre- and post-intervention., Results: Participants reported minimal difficulty with swallowing, yet results revealed a significant increase in EMG outcome measures, as well as significant improvement in UPDRS total and UPDRS motor scores. No significant differences were revealed for SWAL-QOL., Conclusion: Increases in EMG timing measures may suggest that group singing results in the prolongation of laryngeal elevation, protecting the airway from foreign material for longer periods of time during swallow. Combined with the improvement in UPDRS clinical measures, therapeutic singing may be an engaging early intervention strategy to address oropharyngeal dysphagia while also benefiting additional clinical symptoms of PD., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Purpose Interventions focused on singing may provide additional benefits to established voice and respiratory therapies, due to their greater emphasis on the respiratory muscle control system in those with Parkinson's disease (PD) progresses. The purpose of this study was to examine if singing can improve voice, respiratory pressure and quality of life (QOL) in persons with PD. Methods This pilot study measured the effects of a singing intervention in 27 participants with PD. Participants were assigned to a high (met twice weekly) or low (met once weekly) dosage group. Voice, respiratory and QOL measures were recorded before and after an 8-week singing intervention. Sessions were led by board-certified music therapists and included a series of vocal and articulation exercises and group singing. Results Both groups demonstrated significant improvements in maximum inspiratory and expiratory pressure, as well as phonation time. While other voice measures improved, they did not reach statistical significance. Voice QOL and whole health QOL also significantly improved. Conclusion These results suggest singing may be a beneficial and engaging treatment choice for improving and maintaining vocal function and respiratory pressure in persons with PD. Implications for Rehabilitation In a small sample, group singing proved beneficial for improving voice and respiratory impairment in persons with Parkinson's disease. Completing group singing one time per week for 8 weeks was as effective as completing group singing two times per week for 8 weeks in persons with Parkinson's disease. Group singing is an effective means of improving overall quality of life in persons with Parkinson's disease.

Premotor areas play a critical role in the control of repetitive movements. While research has shown that movement-related oscillations are abnormal during repetitive movements in persons with Parkinson's disease (PD), there is limited research examining the contribution of premotor areas, such as the contralateral dorsal premotor area (PMd) and supplementary motor area (SMA), to this impairment. This study compared movement-related oscillations over premotor regions between participants with PD and control participants. Nine participants with PD off and on medication and nine matched control participants were studied. Participants performed cued index finger movements. Spectral power was derived from electroencephalographic recordings from electrodes FC3/FC4 and Cz over the regions of the contralateral PMd and SMA respectively. Movement-related alpha and beta band oscillations were suppressed over electrode FC3/FC4 (contralateral PMd) in participants with PD, particularly at higher movement rates, in both the off and on medication conditions compared to control subjects. The pattern of movement-related oscillations recorded from Cz (SMA) was similar between PD and control groups. This would suggest that the region of the contralateral PMd may be preferentially involved with the control of externally cued repetitive movements and that changes in this activity may contribute to the deterioration of repetitive finger movements at higher rates in persons with PD., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Objective: Impaired repetitive movement in persons with Parkinson's disease (PD) is associated with reduced amplitude, paradoxical hastening and hesitations or arrest at higher movement rates. This study examined the effects of movement rate and medication on movement-related cortical oscillations in persons with PD., Methods: Nine participants with PD were studied off and on medication and compared to nine control participants. Participants performed index finger movements cued by tones from 1 to 3 Hz. Movement-related oscillations were derived from electroencephalographic recordings over the region of the contralateral sensorimotor cortex (S1/M1) during rest, listening, or synchronized movement., Results: At rest, spectral power recorded over the region of the contralateral S1/M1 was increased in the alpha band and decreased in the beta band in participants with PD relative to controls. During movement, the level of alpha and beta band power relative to baseline was significantly reduced in the PD group, off and on medication, compared to controls. Reduced movement amplitude and hastening at movement rates near 2 Hz was associated with abnormally suppressed and persistent desynchronization of oscillations in alpha and beta bands., Conclusion: Motor cortical oscillations in the alpha and beta bands are abnormally suppressed in PD, particularly during higher rate movements., Significance: These findings contribute to the understanding of mechanisms underlying impaired repetitive movement in PD., (Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Objectives: To determine (1) the relationship between assisted timed Up and Go (TUG) performance and the Parkinson's Disease Questionnaire-39 (PDQ-39), and (2) whether adjusting the TUG score (adding time) improves the relationship between TUG performance and the PDQ-39 in persons with Parkinson disease (PD) who use assistive devices or push off, or both., Design: Cross-sectional., Setting: Twenty participating National Parkinson Foundation Centers of Excellence., Participants: Data were obtained from participants (N=6624) without exclusion at the 20 participating sites., Interventions: Not applicable., Main Outcome Measures: The relationship between TUG scores and PDQ-39 mobility scores was determined using the method of linear least squares. Adjusted scores were determined through minimizing the sum of the squared error., Results: The correlation between assisted TUG scores and PDQ-39 mobility scores was slightly lower (R(2)=.384) compared with the correlation between nonassisted TUG scores and PDQ-39 mobility scores (R(2)=.409). Adjusting assisted TUG performance scores for push off and for use of an assistive device resulted in a modest increase in correlation (R(2)=.399)., Conclusions: Applying adjustments to assisted TUG may provide clinically important information for evaluating balance, mobility, and falls, and for determining the most effective therapeutic strategies for persons with PD., (Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Introduction: Progressive supranuclear palsy (PSP) is the most common form of atypical Parkinsonism; however it is underdiagnosed and often misdiagnosed as Parkinson's disease (PD)., Methods: We investigated gait initiation (GI) and gait performance in a total of 36 participants (12 PSP, 12 PD and 12 healthy age- and gender-matched controls) to gain further insight into specific motor deficits that characterize dynamic postural control and gait in PSP. Anticipatory postural adjustments (APAs), quantified by center of pressure (COP) displacement and speed prior to an initial heel off, and the maximum distance (COPCOM) between COP and center of mass (COM) during all three GI phases were calculated to evaluate dynamic postural control. Steady-state gait performance was also evaluated and compared across the groups., Results: APAs in PSP were significantly altered such that the posterior COP shift is profoundly diminished when compared to PD (p < 0.05). Moreover, proper velocity control during GI in PSP was affected, particularly in the mediolateral direction, when compared to PD (p < 0.05). The diminished COPCOM distance is further indicative of more severe dynamic postural instability in PSP than in PD (p < 0.05). Significant differences in spatiotemporal parameters, inter-step variability, and asymmetry during gait in PSP, in comparison with PD were also identified (all p's < 0.05)., Conclusion: The present study reveals that the compensatory GI strategy in PSP is distinct from PD and paradoxically induces lateral instability. Further, gait performance in PSP is slower and more variable which could be the consequence of lateral instability and fear of falling., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background Context: Using diagnostic anesthetic blocks, the lumbar zygapophysial (facet) joint has been shown to be the primary cause of pain in approximately 15% of patients with chronic low back pain. Radiofrequency neurotomy (RFN) of the lumbar medial branch innervating the zygapophysial joint has been shown to provide a significant decrease in pain in patients selected by dual comparative anesthetic blocks, but quantitative improvements in mobility have not been fully elucidated. A theoretical concern with RFN is that the multifidus muscle, a stabilizing paraspinal muscle, is also denervated during this procedure, which may have adverse effects on mobility and spine stability., Purpose: The purpose of this study was to examine gait kinematics and muscle activity of the low back during treadmill walking both before and after RFN., Study Design: Case study., Patient Sample: One 33-year-old female, with 15 years of chronic left low back pain and a diagnosis of L4/L5 lumbar zygapophysial joint pain by dual comparative anesthetic blocks was studied., Outcome Measures: Self-reported measures of perceived pain and effort; in addition to physiologic measures of heart rate, gait kinematics and surface electromyography (EMG) activity of the multifidus and erector spinae muscles were collected before and after the procedure., Methods: The participant walked for 15 consecutive minutes on a treadmill. The first and last 5-minute intervals were at a self-selected pace, and the middle 5-minute interval was at a 50% increase of the self-selected pace. Gait kinematics and lumbar paraspinal surface EMG activity were recorded during the last minute of each walking interval. Heart rate, perceived effort, and perceived pain were also collected at the end of each walking interval. Data were collected both 7 and 1 days before RFN, and on the following days post-RFN: 0, 8, 14, 28, and 58., Results: Perceived effort did not change despite an increase in treadmill speed and heart rate. Pain decreased by 60% in the first two weeks and by 92% by 4 weeks post-RFN. There were also gradual positive changes in gait kinematics across all post-sessions and an immediate and sustained decrease in surface EMG activity over the left multifidus and erector spinae muscles following RFN., Conclusions: The results of this pilot study are the first to show quantitative positive changes in gait and muscle activity post-RFN, suggesting that the relationship between this procedure and mobility warrant further investigation., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Differentiating movement disorders is critical for appropriate treatment, prognosis, and for clinical trials. In clinical trials this is especially important as effects can be diluted by inclusion of inappropriately diagnosed participants. In early disease duration phases, disorders often have overlapping clinical features, such as impairments in repetitive finger movement, making diagnosis challenging. The purpose of this pilot study was to examine and compare repetitive finger movement performance in participants diagnosed with idiopathic Parkinson's disease, Progressive Supranuclear Palsy, and spinocerebellar ataxias., Methods: Participants completed an unconstrained index finger flexion/extension movement (i.e. finger tap) in time with an incremental acoustic tone. Measures of movement rate, movement amplitude, and coefficient of variation were compared among groups., Results: Significant differences between groups were revealed for movement rate at faster tone rates. Participants with Parkinson's disease tended to tap faster than the tone rate while participants with Progressive Supranuclear Palsy and spinocerebellar ataxia tended to tap slower. No significant differences were revealed for movement amplitude, but participants with spinocerebellar ataxia demonstrated greater variance in amplitude than participants with Parkinson's disease., Conclusion: Quantitative analysis of repetitive finger movement performance at faster rates may be helpful to differentiate Parkinson's Disease, Progressive Supranuclear Palsy and spinocerebellar ataxia.

Background and Purpose: Gait dysfunction is a common target for pharmacological, behavioral, and surgical interventions in persons with Parkinson disease. However, the responsiveness of gait speed, that is, clinically important difference, is not well described in the literature for this population. The purpose of this study was to determine the magnitude of meaningful difference in gait speed using multiple methods of assessment and utilizing a large sample of participants inclusive of various stages of disease severity., Methods: Gait speed was measured using an instrumented walkway in 324 ambulatory persons with idiopathic Parkinson disease. Cross-sectional analysis of the clinically important difference for gait speed was performed using distribution- and anchor-based approaches: disability (Schwab and England Activities of Daily Living Scale), disease stage (Modified Hoehn and Yahr Scale), and severity (Unified Parkinson's Disease Rating Scale)., Results: Using distribution-based analyses and effect size metrics, the small important difference in gait speed was 0.06 m/s, moderate was 0.14 m/s, and large was 0.22 m/s. Applying previously established cut-points for small, moderate, and large change in the motor scale score, the associated changes in gait speed that might be expected are 0.02, 0.06, and 0.10 m/s., Discussion and Conclusions: Our data revealed that the clinically important difference in gait speed among persons with Parkinson disease on medication ranged from 0.05 m/s to 0.22 m/s by distribution-based analysis and ranged from 0.02 m/s to 0.18 m/s per level within the anchor-based metrics. These data will aid in evaluating the effectiveness of interventions to improve gait speed in persons with Parkinson disease.Video Abstract available. See video (Supplemental Digital Content 1, http://links.lww.com/JNPT/A77) for more insights from the authors.

Background: Given that music therapists work across a wide range of disabilities, it is important that therapists have at least a fundamental understanding of the neurophysiology associated with the client/patient populations that they serve. Yet, there is a large gap of evidence regarding the neurophysiological changes associated with applying music as therapy., Objective: The purpose of this article is to provide music therapists with a general background in neuroplasticity principles that can be applied to the use of music therapy with multiple populations., Methods: This article will review literature on neuroplasticity and literature supporting the specific attributes of music therapy that apply to neuroplasticity. Finally, examples of how to use neuroplasticity principles to explain and support clinical music therapy will be provided., Results: Using the material presented in this review, music therapists will be equipped with information to effectively communicate why music therapy works using three neuroplasticity principles; increase in dopamine, neural synchrony, and a clear signal., Conclusion: Music therapy is a powerful tool to enhance neuroplasticity in the brain., (© the American Music Therapy Association 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Purpose: Asymmetric step length is a problem common to many orthopedic and neurologic populations. Herein, we compare step length aftereffects during overground gait after two rehabilitation intervention strategies to combat step length asymmetry: split-belt treadmill (SBT) walking and unilateral stepping., Methods: Eighteen healthy young adults (22 ± 3 yr) first performed 10 overground gait trials. Participants then walked for 10 min under three different treadmill conditions in a randomized order: SBT walking, slow unilateral stepping, and fast unilateral stepping. Immediately after each treadmill condition, participants performed ten overground gait trials. Mean step length asymmetry was calculated across the first five strides of the overground gait trials to assess the storage of aftereffects after each treadmill condition. We also explored the lower extremity kinematics during each treadmill condition to investigate movement patterns that lead to greatest aftereffects., Results: Significantly higher step length asymmetry was observed in overground gait trials after SBT walking compared to those after slow and fast unilateral stepping, indicating greater aftereffect/carryover of the SBT walking pattern to overground gait. During fast unilateral stepping, increased flexion in the hip, knee, and ankle of the stationary limb was significantly associated with increased step length aftereffects., Conclusions: The aftereffects observed after acute SBT walking were significantly greater than those after unilateral stepping. Both exercises induce aftereffects of similar kinematic patterns, although likely through different mechanisms. In sum, SBT walking induces the greatest aftereffects, although unilateral stepping also induces a change in gait behavior. During unilateral stepping, the largest aftereffects occur when the walker does not simply fully extend the stationary limb and allow the treadmill to passively move the stepping limb during stance.

Background: Cognitive impairments in Parkinson disease (PD) manifest as deficits in speed of processing, working memory, and executive function and attention abilities. The gait impairment in PD is well documented to include reduced speed, shortened step lengths, and increased step-to-step variability. However, there is a paucity of research examining the relationship between overground walking and cognitive performance in people with PD., Objective: This study sought to examine the relationship between both the mean and variability of gait spatiotemporal parameters and cognitive performance across a broad range of cognitive domains., Design: A cross-sectional design was used., Methods: Thirty-five participants with no dementia and diagnosed with idiopathic PD completed a battery of 12 cognitive tests that yielded 3 orthogonal factors: processing speed, working memory, and executive function and attention. Participants completed 10 trials of overground walking (single-task walking) and 5 trials of overground walking while counting backward by 3's (dual-task walking)., Results: All gait measures were impaired by the dual task. Cognitive processing speed correlated with stride length and walking speed. Executive function correlated with step width variability. There were no significant associations with working memory. Regression models relating speed of processing to gait spatiotemporal variables revealed that including dual-task costs in the model significantly improved the fit of the model., Limitations: Participants with PD were tested only in the on-medication state., Conclusions: Different characteristics of gait are related to distinct types of cognitive processing, which may be differentially affected by dual-task walking due to the pathology of PD., (© 2014 American Physical Therapy Association.)

Objective: To examine the relationship between Timed Up and Go (TUG) performance, verbal executive function (EF) performance, and quality-of-life (QOL) measures in Parkinson's disease (PD)., Design: Cross-sectional., Setting: Sixteen movement disorder centers from across the United States., Participants: Patients with PD (N=1964)., Interventions: Not applicable., Main Outcome Measures: TUG test, immediate and delayed 5-word recall, verbal fluency, PD QOL Questionnaire., Results: TUG performance and verbal EF performance were significantly associated with, and predictors of, QOL measures, having the greatest association and predictability with the mobility domain of the QOL measures., Conclusions: The TUG test and verbal EF tests have QOL correlates, making the combined evaluation of mobility, cognitive, and QOL decline a potential examination tool to evaluate the sequelae of PD., (Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: Locomotor adaptation enables safe, efficient navigation among changing environments. We investigated how healthy young (HYA) and older (HOA) adults and persons with Parkinson's disease (PD) adapt to walking on a split-belt treadmill, retain adapted gait parameters during re-adaptation, and store aftereffects to conventional treadmill walking., Methods: Thirteen PD, fifteen HYA, and fifteen HOA walked on a split-belt treadmill for ten minutes with one leg twice as fast as the other. Participants later re-adapted to the same conditions to assess retention of the split-belt gait pattern. After re-adaptation, we assessed aftereffects of this pattern during conventional treadmill walking., Results: Persons with PD exhibited step length asymmetry throughout many adaptation and adaptive learning conditions. Early adaptation was similar across groups, though HYA and HOA continued to adapt into late adaptation while PD did not. Despite pervasive step length asymmetry among conditions which were symmetric in HYA and HOA, persons with PD demonstrated significant step length aftereffects during conventional treadmill walking after split-belt walking., Conclusions: Though they may exhibit a default asymmetry under various walking conditions, persons with PD can adapt and store new walking patterns., Significance: Locomotor adaptation therapy may be effective in ameliorating asymmetric gait deficits in persons with PD., (Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

External pacing cues, dopaminergic medication, and bilateral subthalamic nucleus deep brain stimulation (STN-DBS) improve repetitive movements performed at low rates. When the pacing rate is increased to frequencies near 2 Hz and above, both external pacing cues and Parkinson's medication were shown to be ineffective at improving repetitive finger movement performance. It remains unclear if STN-DBS improves the performance of repetitive finger movements at high pacing rates. This study examined the effects of STN-DBS on the amplitude and rate of repetitive finger movement across a range of external pacing rates. Nine participants with STN-DBS (OFF and ON stimulation) and nine matched healthy adults performed repetitive index finger flexion movements paced by an acoustic tone that increased from 1.0 to 3.0 Hz. OFF stimulation, most subjects moved at rates that were substantially higher (hastening pattern) or lower (bradykinesia pattern) than the tone rate, particularly at high pacing rates. ON stimulation, movement rate improved in subjects with the bradykinesia pattern, but not in those with the hastening pattern. Overall, STN-DBS did not significantly affect movement rate. In contrast, STN-DBS significantly (p<0.05) improved movement amplitude across all pacing rates. These findings demonstrate that STN-DBS improves movement amplitude, but had no effect on the rate of movement in participants with a hastening pattern. Separately testing movement amplitude and movement rate using both high and low rate externally paced cues in the clinical environment may aid in the diagnosis and treatment of people with Parkinson's disease., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Gait initiation is a transitional task involving a voluntary shift from a static, stable position to a relatively less-stable state of locomotion. During gait initiation, anticipatory postural adjustments precede stepping in order to generate forward momentum while balance is maintained. While deficits in gait initiation are frequently reported for persons with Parkinson's disease, there is a paucity of information regarding gait initiation performance in persons with Essential Tremor. We investigated anticipatory postural adjustments and spatiotemporal characteristics of gait initiation in persons with Essential Tremor and compared them to persons with Parkinson's disease as well as age-matched neurologically healthy adults. Twenty-four persons with Essential Tremor, 31 persons with Parkinson's disease, and 38 age-matched controls participated. We compared anterior-posterior and mediolateral center of pressure movements and spatiotemporal stepping characteristics during gait initiation among the three groups using Mann-Whitney U-tests with Bonferroni corrections for multiple comparisons and one-way ANOVAs. Persons with Parkinson's disease demonstrated significantly reduced displacement and velocity of the center of pressure during early phases of anticipatory postural adjustments relative to controls. Displacement of the center of pressure was also reduced in persons with Essential Tremor, although at a later stage of the gait initiation process. Persons with Parkinson's disease and Essential Tremor demonstrated similar reductions in step length during gait initiation when compared to controls. Persons with Parkinson's disease and Essential Tremor exhibit different deficits in gait initiation when compared to healthy older adults. Therefore, this study provides further evidence differentiating motor control features in these movement disorders., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Objective: To investigate the ability of the Timed Up & Go test to identify patients with Parkinson's disease at risk for a fall., Design: Cross-sectional cohort study., Setting: Sixteen participating National Parkinson's Foundation Centers of Excellence., Participants: A query yielded a total of 2985 records (1828 men and 1157 women). From these, 884 were excluded because of a lack of crucial information (age, diagnosis, presence of deep brain stimulation, disease duration, inability of performing the Timed Up & Go test without assistance) at the time of testing, leaving 2097 patients included in the analysis., Interventions: Not applicable., Main Outcome Measures: The primary outcome measure for this study was falls. The chief independent variable was the Timed Up & Go test., Results: The initial model examined the prediction of falls from the Timed Up & Go test, adjusting for all study covariates. The estimated models in the imputed data sets represented a significant improvement above chance (χ(2) range [df=17], 531.29-542.39, P<.001), suggesting that 74% of participants were accurately classified as a faller or nonfaller. The secondary model in which the question of whether the effect of Timed Up & Go test was invariant across disease severity demonstrated 75% of participants were accurately classified as a faller or nonfaller. Additional analysis revealed a proposed cut score of 11.5 seconds for discrimination of those who did or did not fall., Conclusions: The findings suggest that the Timed Up & Go test may be an accurate assessment tool to identify those at risk for falls., (Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

During split-belt treadmill walking the speed of the treadmill under one limb is faster than the belt under the contralateral limb. This unique intervention has shown evidence of acutely improving gait impairments in individuals with neurologic impairment such as stroke and Parkinson's disease. However, oxygen use, heart rate and perceived effort associated with split-belt treadmill walking are unknown and may limit the utility of this locomotor intervention. To better understand the intensity of this new intervention, this study was undertaken to examine the oxygen consumption, oxygen cost, heart rate, and rating of perceived exertion associated with split-belt treadmill walking in young healthy adults. Fifteen participants completed three sessions of treadmill walking: slow speed with belts tied, fast speed with belts tied, and split-belt walking with one leg walking at the fast speed and one leg walking at the slow speed. Oxygen consumption, heart rate, and rating of perceived exertion were collected during each walking condition and oxygen cost was calculated. Results revealed that oxygen consumption, heart rate, and perceived effort associated with split-belt walking were higher than slow treadmill walking, but only oxygen consumption was significantly lower during both split-belt walking than fast treadmill walking. Oxygen cost associated with slow treadmill walking was significantly higher than fast treadmill walking. These findings have implications for using split-belt treadmill walking as a rehabilitation tool as the cost associated with split-belt treadmill walking may not be higher or potentially more detrimental than that associated with previously used treadmill training rehabilitation strategies.

Background: High frequency stimulation (HFS) of the subthalamic nucleus is one of the most effective treatments for advanced Parkinson's disease (PD). HFS has provided beneficial improvements in the cardinal features of PD, but has not been proven as effective for addressing the axial predominant levodopa resistant symptoms, such as speech disturbances, gait disturbances, and postural instability. Recent studies have suggested that changes in stimulation parameters may influence differing PD symptoms., Objective: The purpose of this study was to compare the effects of low frequency stimulation (LFS) versus HFS on the Unified Parkinson's Disease Rating Scale (UPDRS), gait, balance, and verbal fluency., Methods: Eight tremor dominant and nine non-tremor dominant participants with bilateral deep brain stimulation of the subthalamic nucleus were tested off stimulation, during LFS, and during HFS., Results: Results revealed that HFS significantly reduced UPDRS tremor score in the tremor dominant group; however no differences emerged within the non-tremor dominant group. No differences between groups or stimulation conditions were found for gait, balance, and verbal fluency measures., Conclusion: These results may suggest that HFS is better than LFS for reducing tremor in tremor dominant patients. However, patients with mild or no tremor show no acute differences in benefit from LFS as compared to HFS.

Background: Coordination between the upper and lower extremities is important to providing dynamic stability during human gait. Though limited, previous research has suggested that interlimb coordination may be impaired in persons with Parkinson's disease. We extend this previous work using continuous analytical techniques to enhance our understanding of interlimb coordination during gait in persons with Parkinson's disease., Methods: Eighteen adults with Parkinson's disease and fifteen healthy older adults walked overground while undergoing three-dimensional motion capture. Ipsilateral and contralateral interlimb coordination between the sagittal shoulder and hip angles was assessed using cross-covariance techniques. Independent samples and paired samples t-tests compared measures of interlimb coordination between groups and between sides within the participants with Parkinson's disease, respectively. Pearson's correlations were applied to investigate associations between interlimb coordination measures and subscores of gait, posture, and bradykinesia on the Unified Parkinson's Disease Rating Scale., Findings: Ipsilateral and contralateral interlimb coordination was reduced in persons with Parkinson's disease compared to the healthy older adults. Ipsilateral coordination between the upper and lower extremities more affected by disease was found to be negatively associated with clinical scores of gait and posture. Interlimb coordination was not significantly associated with clinical measures of bradykinesia., Interpretation: Persons with Parkinson's disease exhibit reduced interlimb coordination during gait when compared to healthy older adults. These reductions in coordination are related to clinically-meaningful worsening of gait and posture in persons with PD and coordination of arm and leg movements should be considered in future research on gait therapy in this population., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

The split-belt treadmill (SBT) has recently been used to rehabilitate locomotor asymmetries in clinical populations. However, the joint mechanics produced while walking on a SBT are not well-understood. The purpose of this study was to investigate the lower extremity sagittal joint moment patterns produced by each limb during SBT walking and provide insight as to how these joint moment patterns may be useful in rehabilitating unilateral gait deficits. Thirteen healthy young volunteers walked on the SBT with the belts tied and in a "SPLIT" session in which one belt moved twice as fast as the other. Sagittal lower extremity joint moment and ground reaction force impulses were then calculated over the braking and propulsive phases of the gait cycle. Paired t-tests were performed to analyze magnitude differences between conditions (i.e. the fast and slow limbs during SPLIT vs. the same limb during tied-belt walking) and between the fast and slow limbs during SPLIT. During the SPLIT session, the fast limb produced higher ground reaction force and ankle moment impulses during the propulsive and braking phases, and lower knee moment impulses during the propulsive phase when compared to the slow limb. The knee moment impulse was also significantly higher during braking in the slow limb than in the fast limb. The mechanics of each limb during the SPLIT session also differed from the mechanics observed when the belt speeds were tied. Based on these findings, we suggest that each belt may have intrinsic value in rehabilitating specific unilateral locomotor deficits., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

During gait initiation (GI), consistency of foot placement while stepping is important in making successful transitions from a state of stable static posture to an unstable state of dynamic locomotion. In populations characterized by gait dysfunction and postural instability, such as persons with Parkinson's disease (PD), the ability to generate a consistent stepping pattern during GI may be essential in the prevention of falls. However, little is known about GI variability in persons with PD as compared to their healthy elderly peers. Therefore, this study investigated spatiotemporal variability during the first two steps of GI in 46 persons with idiopathic PD and 49 healthy age-matched adults. Stepping characteristics, including the length, width, and time of the first two steps of GI as well as their coefficients of variation (CV) were compared between groups. Persons with PD initiated gait with significantly shorter steps (swing step length=.463 vs. .537 m, stance step length=.970 vs. 1.10 m) and higher variability in step length (swing step CV=8.82 vs. 5.45, stance step CV=6.76 vs. 3.61). Persons with PD also showed significantly higher variability in the time of the swing step (swing step CV=10.0 vs. 7.4). GI variability did not differ significantly between disease stages in persons with PD. Because greater variability in these measures during gait is related to an increased risk of falls, we propose that higher GI variability may play a considerable role in falls frequently observed during transitions from quiet standing in PD., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Objective: To examine whether Parkinson's disease (PD) affects gait behavior and stability while walking over an obstacle., Design: Parallel group comparisons were completed in which participants completed 5 trials of normal walking and 5 trials of obstacle crossing while gait kinematics and kinetics were collected., Setting: University biomechanics laboratory., Participants: Individuals with PD (n=10) and age- and sex-matched healthy older adults (n=10)., Interventions: Not applicable., Main Outcome Measures: Gait parameters, obstacle clearance parameters, and center of mass motion were calculated during normal walking and obstacle crossing., Results: Results revealed that decrements in gait performance in individuals with PD were amplified during obstacle crossing, suggesting that due to disease-related degradation, individuals with PD chose a more conservative strategy for obstacle crossing. Moreover, an increased duration of single limb support (18% increase), a decrease in anteroposterior range of motion (20% decrease), and an increase in mediolateral range of motion (36% increase, though not significant) coupled with the reduction in the distance between the center of pressure and center of mass (mean of 21% decrease across toe-off and heel strike) and increase in margin of stability (31% increase at toe-off and 71% increase at heel strike) may suggest that deficits in muscle strength and balance may contribute to this impairment., Conclusions: Persons with PD alter their behavior to reduce the mechanical demands and increase dynamic stability during obstacle avoidance tasks., (Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Gait performance is widely evaluated to assess health status in older adult populations. While several investigators have presented normative values for spatiotemporal gait parameters drawn from older adult populations, the literature has been void of large-scale cohort studies, which are needed in order to provide quantitative, normative gait data in persons with Parkinson's disease. The aim of this investigation was to provide reference values for clinically important gait characteristics in a large sample of ambulatory persons with Parkinson's disease to aid both clinicians and researchers in their evaluations and treatments of gait impairment., Methodology/principal Findings: Gait performance was collected in 310 individuals with idiopathic Parkinson's disease as they walked across a pressure sensitive walkway. Fourteen quantitative gait parameters were measured and evaluated with respect to Hoehn and Yahr disease staging and gender. Disease duration and age were controlled for in all analyses. Individuals with the greatest Parkinson's disability walked significantly slower with shorter steps and stride lengths than the mild and moderately affected groups. Further, the most affected patients spent more time with both feet on the ground, and walked with a wider base of support than the moderately disabled patients. No differences were detected between the mild and moderate disability groups on any of the gait parameters evaluated., Conclusions/significance: Reference values for 14 gait parameters in a large cohort of ambulatory patients with Parkinson's disease are provided and these may be highly useful for assessing and interpreting an individual's gait dysfunction. It is important for clinicians and researchers to appreciate the lack of change in quantitative parameters as PD patients move from mild to moderate gait impairment.

Performance of repetitive finger movements is an important clinical measure of disease severity in patients with Parkinson's disease (PD) and is associated with a dramatic deterioration in performance at movement rates near 2 Hz and above. The mechanisms contributing to this rate-dependent movement impairment are poorly understood. Since clinical and experimental testing of these movements involve prolonged repetition of movement, a loss of force-generating capacity due to peripheral fatigue may contribute to performance deterioration. This study examined the contribution of peripheral fatigue to the performance of unconstrained index finger flexion movements by measuring maximum voluntary contractions (MVC) immediately before and after repetitive finger movements in patients with PD (both off- and on-medication) and matched control subjects. Movement performance was quantified using finger kinematics, maximum force production, and electromyography (EMG). The principal finding was that peak force and EMG activity during the MVC did not significantly change from the pre- to post-movement task in patients with PD despite the marked deterioration in movement performance of repetitive finger movements. These findings show that the rate-dependent deterioration of repetitive finger movements in PD cannot be explained by a loss of force-generating capacity due to peripheral fatigue, and further suggest that mechanisms contributing to impaired isometric force production in PD are different from those that mediate impaired performance of high-rate repetitive movements., (Copyright 2010 Elsevier Ireland Ltd. All rights reserved.)

Objective: Currently, electroencephalography (EEG) cannot be used to record cortical activity during clinically effective DBS due to the presence of large stimulation artifact with components that overlap the useful spectrum of the EEG. A filtering method is presented that removes these artifacts whilst preserving the spectral and temporal fidelity of the underlying EEG., Methods: The filter is based on the Hampel identifier that treats artifacts as outliers in the frequency domain and replaces them with interpolated values. Performance of the filter was tested with a synthesized DBS signal and actual data recorded during bilateral monopolar DBS., Results: Mean increases in signal-to-noise ratio of 7.8dB for single-frequency stimulation and 13.8dB for dual-frequency stimulation are reported. Correlation analysis between EEG with synthesized artifacts and artifact-free EEG reveals that distortion to the underlying EEG in the filtered signal is negligible (r(2)>0.99)., Conclusions: Frequency-domain Hampel filtering has been shown to remove monopolar DBS artifacts under a number of common stimulation conditions used for the treatment of Parkinson's disease., Significance: Application of frequency-domain Hampel filtering will allow the measurement of EEG in patients during clinically effective DBS and thus may increase our understanding of the mechanisms of action of this important therapeutic intervention., (Copyright 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

In young healthy adults, syncopated finger movements (movements between consecutive beats) are characterized by a frequency-dependent change in phase at movement rates near 2 Hz. A similar frequency-dependent phase transition is observed during bimanual anti-phase (asymmetric) tasks in healthy young adults, but this transition frequency is significantly lowered in both patients with Parkinson's disease (PD) and older adults. To date, no study has examined the transition frequency associated with unimanual syncopated movements in patients with PD or older adults. This study examined the effects of movement frequency on the performance of unconstrained syncopated index finger flexion movements in patients with PD, older adult subjects matched to patients with PD, and young adult subjects. Syncopated movements were paced by an acoustic tone that increased in frequency from 1 to 3 Hz in 0.25 Hz increments. Movement phase was quantified and the movement frequency where subjects transitioned from syncopation to synchronization was compared between groups. The principal finding was a marked impairment in the ability of patients with PD to perform syncopated movements when off medication. Medication did not significantly improve performance. In addition, the transition frequency for older adult subjects was lower than young adult subjects. These findings demonstrate that, similar to bimanual tasks, the coordination dynamics associated with unimanual syncopated finger movements transition from a stable to an unstable pattern at significantly lower frequencies in patients with PD and older adults compared to young adults.

Performance of repetitive hand movements in patients with Parkinson's disease (PD) is characterized by slowness, reduced movement amplitude, and hesitation or arrests in ongoing movement. Currently, the factors and mechanisms contributing to impaired performance of these types of movement remain poorly understood. This study examined the effects of movement frequency and medication on the performance of unconstrained index finger flexion movements in patients with PD and matched control subjects. Movements were synchronized with an auditory tone as the frequency of the tone was increased from 1 to 3 Hz in 0.25 Hz increments. Movement performance was quantified based upon finger kinematics and electromyography (EMG) recorded from the index finger flexors and extensors. The principal finding was that patients with PD showed a dramatic reduction in movement amplitude, an increase in movement frequency, and a loss of phase when the movement frequency reached or exceeded 2 Hz. This deficit was not significantly improved with medications. In contrast, all control subjects could synchronize to 3 Hz. These findings show that movement frequency is a major determinant of hypokinesia during repetitive movements and may contribute to hesitations and movement arrest during clinical testing of bradykinesia in the upper limb of patients with PD., ((c) 2009 Movement Disorder Society.)