The reliability and minimal detectable change of the cardiovascular response and self-selected exercise intensity during forward and backward treadmill exercise in individuals with Parkinson disease.

OBJECTIVE: This study examined test-retest relative (intraclass correlation coefficient) and absolute (minimum detectable change) reliabilities for heart rate, blood pressure, rate of perceived exertion, and the cerebral oxygen response during both forward and backward treadmill walking in clients with Parkinson disease. In addition, the intensity of exercise based on the individual's heart rate response during forward and backward walking treadmill work was assessed. DESIGN: Test-retest reliability study. SUBJECTS: A total of 22 clients with Parkinson disease (Hoehn and Yahr stages 1-3). MAIN MEASURES: Outcome measures of heart rate, blood pressure, and cerebral oxygen response were assessed during forward and backward walking on a treadmill for a total of 20 minutes up to an intensity based on the clients' prior treadmill work and their rate of perceived exertion. RESULTS: Good to excellent 6-8 day test-retest findings for both forward (intraclass correlation coefficient(2,1), 0.89-0.99) and backward (intraclass correlation coefficient(2,1), 0.82-0.99) treadmill walking were found for heart rate, blood pressure, cerebral oxygen response, and the participants' rate of perceived exertion. Low minimum detectable change (MDC)95 values were found for heart rate (4.9 and 4.8), rate of perceived exertion (1.0 and 1.6), and cerebral oxygen response (1.2 and 0.92), during forward and backward walking, respectively. All treadmill exercise heart rates attained by participants were within an intensity of 54%-87% of the client's predicted maximal heart rate. CONCLUSION: Treadmill exercise training can be included in Parkinson disease exercise programs with relative confidence in test-retest reliability of cardiovascular response. It was also demonstrated that individuals with Parkinson disease previously involved with exercise consistently self-select walking speeds which induce heart rates within recommended guidelines for positive cardiovascular adaptation.

Reliability and Minimal Detectable Change for Sit-to-Stand Tests and the Functional Gait Assessment for Individuals With Parkinson Disease.

BACKGROUND AND PURPOSE: This study examined test-retest relative (intraclass correlation coefficient [ICC]) and absolute (minimum detectable change [MDC]) reliabilities for the 5 times sit-to-stand (5×STS), 30-second sit-to-stand (30sSTS), and the functional gait assessment (FGA) tests in people with Parkinson disease (PD). In addition, correlation of these functional tests with a history of falls was examined over a 6-month period, and the internal consistency of the FGA was established. METHODS: Twenty-two patients with PD (Hoehn and Yahr stages 1-3) completed 3 functional tests over 2 test-retest periods of 6 to 8 days. Falls were self-reported for the prior 6 months. RESULTS AND DISCUSSION: Moderate-to-excellent test-retest ICC(2,2) and MDC95 values were found for the 30sSTS (0.94, 3 times) and ICC(2,1) and MDC95 values were found for the FGA (0.86, 4 points). The 5×STS demonstrated a lower ICC(2,2) and a high MDC95 value (0.74, 10 seconds). A significant correlation was only found between past falls and the FGA test (r =-0.48, P < .05) during session 1. Cronbach α values for the 10-item FGA during session 1 and session 2 were 0.75 and 0.85, respectively. CONCLUSIONS: To assess for change over time, we found the 30sSTS and the FGA tests can be used reliably in patients with PD. A lower FGA score was associated with a higher chance of falls, and good internal consistency of the FGA was found.

Development of a Low-Cost Arduino-Based Sonde for Coastal Applications.

This project addresses the need for an expansion in the monitoring of marine environments by providing a detailed description of a low cost, robust, user friendly sonde, built on Arduino Mega 2560 (Mega) and Arduino Uno (Uno) platforms. The sonde can be made without specialized tools or training and can be easily modified to meet individual application requirements. The platform allows for internal logging of multiple parameters of which conductivity, temperature, and GPS position are demonstrated. Two design configurations for different coastal hydrographic applications are highlighted to show the robust and versatile nature of this sensor platform. The initial sonde design was intended for use on a Lagrangian style surface drifter that recorded measurements of temperature; salinity; and position for a deployment duration of less than 24 h. Functional testing of the sensor consisted of a 55 h comparison with a regularly maintained water quality sensor (i.e., YSI 6600 sonde) in Mobile Bay, AL. The temperature and salinity data were highly correlated and had acceptable RMS errors of 0.154 °C and 1.35 psu for the environmental conditions. A second application using the sonde platform was designed for longer duration (~3-4 weeks); subsurface (1.5-4.0 m depths) deployment, moored to permanent structures. Design alterations reflected an emphasis on minimizing power consumption, which included the elimination of the GPS capabilities, increased battery capacity, and power-saving software modifications. The sonde designs presented serve as templates that will expand the hydrographic measurement capabilities of ocean scientists, students, and teachers.

The Effect of Parkinson Drug Timing on Cardiovascular Response during Treadmill Exercise in a Person with Parkinson Disease and Freezing of Gait.

PURPOSE: To examine the response of cerebral oxygenation during treadmill walking in a person with Parkinson disease (PD) who experiences freezing of gait (FOG) and to determine whether the oxygen response was related to the timing of his PD medication. Client Description: A 61-year-old man with PD performed two bouts of treadmill testing on the same day, during the on- and off-phases of his PD medication. Measures and Outcome: The client experienced two FOG episodes during the first testing session (on-phase with hypokinetic movement session). Cerebral oxygen response (measured by near-infrared spectroscopy) was stable until the FOG episodes occurred, at which point it decreased until the FOG episode was over. No electrocardiogram (ECG) changes or lightheadedness were noted; blood pressure (BP) remained stable. During the second exercise testing session (off-phase with dyskinetic movement session), the client did not experience any FOG episodes, and his cerebral oxygen response remained stable. Toward the end of the second testing session, he experienced lightheadedness and a drop in BP of approximately 30 mmHg, along with significant ST segment depression on his ECG. IMPLICATIONS: Haemodynamic and cerebral oxygen changes occurred that were specific to the timing of the client's PD medication and to his FOG episodes. This case study shows a person with PD demonstrating decreased cerebral oxygenation during FOG, which may be based on his variable response to levodopa medication or may be attributable to as yet unidentified physiologic mechanisms.

Objectif : Analyser la réaction de l'oxygénation cérébrale au cours de la marche sur tapis roulant chez une personne souffrant de la maladie de Parkinson (MP) aux prises avec un blocage de la marche (freezing of gait, FOG), puis déterminer si la réaction de l'oxygène cérébral est liée à l'horaire selon lequel ses médicaments pour la MP sont administrés. Description du client : Un homme de 61 ans souffrant de la MP. Il a accompli deux tests sur tapis roulant la même journée, lorsque ses médicaments pour la MP étaient en phase et lorsqu'ils étaient hors-phase. Mesures et résultat : Le client a vécu deux épisodes de FOG au cours de la première séance de tests (en phase, avec séance de mouvements hypocinétiques). La réaction de l'oxygène cérébral (mesurée par spectroscopie proche infrarouge) était stable jusqu'à ce que le trouble de la démarche se manifeste; elle a alors décru et est demeurée telle jusqu'à la fin de l'épisode de FOG. Aucun changement à l'électrocardiogramme (ECG) ni aucun étourdissement n'ont été observés et la tension artérielle (TA) est demeurée stable. Au cours de la deuxième séance de tests avec exercice (hors phase, avec séance de mouvements dyscinétiques), le client n'a pas subi d'épisodes de FOG et la réaction de l'oxygène cérébral est demeurée stable. À la fin de la deuxième séance, il a ressenti des étourdissements et sa tension artérielle a chuté d'environ 30 mmHg, et on a aussi constaté un fléchissement appréciable du segment ST de son ECG. Conséquences : Les changements survenus à l'oxygène hémodynamique et à l'oxygène cérébral étaient directement liés au moment de la prise des médicaments pour la MP par le patient et à ses épisodes de FOG. Cette étude de cas démontre que la baisse de l'oxygénation cérébrale au cours des épisodes de FOG chez une personne souffrant de MP peut s'expliquer par sa réaction variable à la lévodopa, ou peut être attribuable à des mécanismes physiologiques non encore identifiés.

Predictors of physical activity in older adults in an independent living retirement community.

This study was undertaken to examine potential predictors of physical activity in older adults in an independent living retirement community. Participants received a self-developed questionnaire that included questions regarding age, gender, educational attainment, physical activity habits, and physicians' physical activity counseling habits. One hundred nine of 150 questionnaires (72.7%) were completed and returned. Multivariate regression analyses revealed that younger age (p=0.013), higher educational attainment (p=0.003), positive attitude toward physical activity (p=0.030), and receiving advice from a physician to be physically active (p=0.001) were all positive predictors of increased physical activity. The results demonstrate that younger age, higher educational attainment, a positive attitude toward physical activity, and receiving advice from a physician to be physically active result in increased physical activity levels of older adults in an independent living retirement community.