Effect of Data and Gap Characteristics on the Nonlinear Calculation of Motion During Locomotor Activities.

This study investigated how data series length and gaps in human kinematic data impact the accuracy of Lyapunov exponents (LyE) calculations with and without cubic spline interpolation. Kinematic time series were manipulated to create various data series lengths (28% and 100% of original) and gap durations (0.05-0.20 s). Longer gaps generally resulted in significantly higher LyE% error values in each plane in noninterpolated data. During cubic spline interpolation, only the 0.20-second gap in frontal plane data resulted in a significantly higher LyE% error. Data series length did not significantly affect LyE% error in noninterpolated data. During cubic spline interpolation, sagittal plane LyE% errors were significantly higher at shorter versus longer data series lengths. These findings suggest that not interpolating gaps in data could lead to erroneously high LyE values and mischaracterization of movement variability. When applying cubic spline, a long gap length (0.20 s) in the frontal plane or a short sagittal plane data series length (1000 data points) could also lead to erroneously high LyE values and mischaracterization of movement variability. These insights emphasize the necessity of detailed reporting on gap durations, data series lengths, and interpolation techniques when characterizing human movement variability using LyE values.

Virtual reality augments effectiveness of treadmill walking training in patients with walking and balance impairments: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: To systematically summarize and examine current evidence regarding the combination of virtual reality and treadmill training in patients with walking and balance impairments. DATA SOURCES: English language randomized controlled trials, participants with walking and balance impairments, intervention group used virtual reality and treadmill, control group only used treadmill with the same training frequency and number of sessions. Six bioscience and engineering databases were searched. METHODS: Two independent reviewers conducted study selection, data extraction, and quality assessment. Methodological quality was assessed using the Physiotherapy Evidence Database (PEDro) scale. RESULTS: Sixteen randomized controlled trials including 829 participants were identified. Compared to treadmill-only training, virtual reality augmented treadmill training induced significantly faster walking (p < 0.001; standardized mean difference (SMD) = 0.55, 95%CI: 0.30 to 0.81), longer step length (p < 0.001; SMD = 0.74, 95%CI: 0.42 to 1.06), narrower step width (p = 0.03; SMD = -0.52, 95%CI: -0.97 to -0.06), longer single leg stance period (p = 0.003; SMD = 0.77, 95%CI: 0.27 to 1.27), better functional mobility (p = 0.003; SMD = -0.44, 95%CI: - 0.74 to -0.15), improved balance function (p = 0.04; SMD = 0.24, 95%CI: 0.01 to 0.47), and enhanced balance confidence (p = 0.03; SMD = 0.73, 95%CI: 0.08 to 1.37). Walking endurance did not differ significantly between groups (p = 0.21; SMD = 0.13, 95%CI: -0.07 to 0.34). CONCLUSIONS: Virtual reality augmented treadmill walking training enhances outcomes compared to treadmill-only training in patients with walking and balance impairments. The results of this review support the clinical significance of combining virtual reality with treadmill training with level 1A empirical evidence.

Walking and Fitness Improvements in a Child With Diplegic Cerebral Palsy Following Motor-Assisted Elliptical Intervention.

PURPOSE: To quantify effects of motor-assisted elliptical (Intelligently Controlled Assistive Rehabilitation Elliptical [ICARE]) training on walking and fitness of a child with cerebral palsy (CP). KEY POINTS: A 12-year-old boy with walking limitations due to spastic diplegic CP (Gross Motor Function Classification System II) participated in 24 sessions of primarily moderate- to vigorous-intensity ICARE exercise. Fitness improvements were evidenced clinically across sessions by the child's capacity to train for longer periods, at faster speeds, and while overriding motor's assistance. Postintervention, the child walked faster with greater stability and endurance and more rapidly completed the modified Time Up and Go test. CONCLUSION: The child's fitness and gait improved following engagement in a moderate- to vigorous-intensity gait-like exercise intervention. RECOMMENDATIONS FOR CLINICAL PRACTICE: Integration of moderate- to vigorous-intensity motor-assisted elliptical training can promote simultaneous gains in fitness and function for children with CP.

Computerized dynamic posturography detects balance deficits in individuals with a history of chronic severe traumatic brain injury.

BACKGROUND: Mild balance deficits can be challenging to detect in individuals with long-standing traumatic brain injuries. This study compared Computerized Dynamic Posturography (CDP) scores from individuals with traumatic brain injuries (TBI) to controls to determine if CDP could differentiate between the two groups and determine if there was a learning effect associated with testing that could be used to guide evaluation of baseline balance. METHODS: Ten ambulatory individuals with a history of severe TBI and 10 individuals without participated in three CDP sessions (24-72 hours apart). During each session, participants performed the Berg Balance Test, Dynamic Gait Index and three trials of a standardized balance assessment and Dynamic Movement Analysis (DMA) scores were recorded for each test. RESULTS: Individuals with TBI scored 93% higher (i.e. reflecting poorer balance) than the control group. The group with TBI exhibited 6.6-times more variability compared to the control group, with estimated variances of 0.3407 and 0.0517, respectively. A learning effect was detected in the group with TBI on the first day of testing (ßTBI F = -0.1241, p-value < 0.01). DISCUSSION: The CDP system detected balance differences between individuals with TBI and controls. Given the documented learning effect, the best of three trials should be used to accurately assess baseline scores.

Lower extremity kinematics during walking and elliptical training in individuals with and without traumatic brain injury.

BACKGROUND AND PURPOSE: Elliptical training may be an option for practicing walking-like activity for individuals with traumatic brain injuries (TBI). Understanding similarities and differences between participants with TBI and neurologically healthy individuals during elliptical trainer use and walking may help guide clinical applications incorporating elliptical trainers. METHODS: Ten participants with TBI and a comparison group of 10 neurologically healthy participants underwent 2 familiarization sessions and 1 data collection session. Kinematic data were collected as participants walked on a treadmill or on an elliptical trainer. Gait-related measures, including coefficient of multiple correlations (a measure of similarity between ensemble joint movement profiles; coefficient of multiple correlations [CMCs]), critical event joint angles, variability of peak critical event joint angles (standard deviations [SDs]) of peak critical event joint angles, and maximum Lyapunov exponents (a measure of the organization of the variability [LyEs]) were compared between groups and conditions. RESULTS: Coefficient of multiple correlations values comparing the similarity in ensemble motion profiles between the TBI and comparison participants exceeded 0.85 for the hip, knee, and ankle joints. The only critical event joint angle that differed significantly between participants with TBI and comparison participants was the ankle during terminal stance. Variability was higher for the TBI group (6 of 11 comparisons significant) compared with comparison participants. Hip and knee joint movement patterns of both participants with TBI and comparison participants on the elliptical trainer were similar to walking (CMCs ≥ 0.87). Variability was higher during elliptical trainer usage compared with walking (5 of 11 comparisons significant). Hip LyEs were higher during treadmill walking. Ankle LyEs were greater during elliptical trainer usage. DISCUSSION AND CONCLUSIONS: Movement patterns of participants with TBI were similar to, but more variable than, those of comparison participants while using both the treadmill and the elliptical trainer. If incorporation of complex movements similar to walking is a goal of rehabilitation, elliptical training is a reasonable alternative to treadmill-based training.Video Abstract available (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A65) for more insights from the authors.

Muscle demand and kinematic similarities between pediatric-modified motor-assisted elliptical training at fast speed and fast overground walking: Real-world implications for pediatric gait rehabilitation.

The purpose of this research was to compare children's lower extremity muscle activity and kinematics while walking at fast pace and training at fast speeds with and without motor-assistance on a pediatric-modified motor-assisted elliptical. Twenty-one children without disabilities were recruited and fifteen completed all three training conditions at self-selected fast pace. Repeated-measures ANOVAs identified muscle demand (peak, mean, duration) differences across device conditions and fast walking. Root mean square error compared overall kinematic profiles and statistical parametric mapping identified kinematic differences between conditions. Motor-assisted training reduced lower extremity muscle demands compared to training without the motor's assistance (16 of 21 comparisons) and to fast walking (all but one comparison). Training without the motor's assistance required less muscle effort than fast walking (16 of 21 comparisons). Kinematic differences between device conditions and fast walking were greater distally (thigh, knee, ankle) than proximally (trunk, pelvis, hip). In summary, transitioning from training with to without the motor's assistance promoted progressively greater activity across the lower extremity muscles studied, with sagittal plane kinematic changes most apparent at the distal joints. Our findings highlight how motor-assistance can be manipulated to customize physiologic challenges to lower extremity muscles prior to fast overground walking.

Effect of gap-filling technique and gap location on linear and nonlinear calculations of motion during locomotor activities.

BACKGROUND: Marker occlusion during camera-based movement analysis is common. Different interpolation techniques are available for estimating location of missing marker trajectories. RESEARCH QUESTION: What is the effect of gap location and interpolation technique on linear and nonlinear measures for a given kinematic time series? METHODS: Kinematic data were recorded during motor-assisted elliptical training and treadmill walking. Gap-filling techniques (i.e., Cubic, Makima, Autoregressive, Nearest Neighbor, and No Interpolation) and gap locations experimentally applied to each cycle across initially complete time series (Gap 1: local minimum and maximum peaks; Gap 2: maximum peaks; Gap 3: maximum peaks at negative slope; Gap 4: random locations) were examined during linear (Maxima and Minima joint angles) and nonlinear [maximum Lyapunov exponent (LyE)] measures. RESULTS: Gap-filling technique and gap location influenced values calculated for linear and nonlinear measures of joint motions. When referenced to the gold standard (original data series without gaps), across all joints studied the average % error of Maxima and Minima joint angles and LyE % error were lower when applying Cubic, Makima, Autoregressive, and Nearest Neighbor techniques compared to No Interpolation (p < 0.0001). The % error of Maxima joint angles was lower for Gaps 1, 3, and 4 compared to Gap 2 (p = 0.0003), while % error of Minima joint angles was lower for Gaps 2 and 3, compared to Gaps 1 and 4 (p < 0.0001). An interaction between gap-filling technique and gap location was identified for LyE % error, in which Gap 4 % error was significantly greater during No Interpolation compared to other gap-filling techniques (p < 0.0001). SIGNIFICANCE: Findings can guide selection of appropriate techniques to manage missing kinematic data points in camera-based motion analysis time series. Gap-filling techniques significantly reduced error in calculating select linear and nonlinear measures of variability, with Cubic most consistently resulting in the greatest reduction in error.

Test-retest reliability and minimal detectable change of the computerized dynamic posturography PROPRIO for adults with chronic traumatic brain injury.

PURPOSE: Balance deficits after brain injury, including reactive recovery from unexpected perturbations, can persist well after rehabilitation is concluded. While traditional clinical assessments are practical, the anticipatory nature of the tasks may mask perceptible balance control. Computerized dynamic posturography can directly quantify capacity to respond to unexpected, external perturbations. This study examined the reliability of the computerized dynamic posturography assessment with the device PROPRIO® 4000 in adults with traumatic brain injury and created the minimal detectable change for its standardized test. METHODS: Ten adults (ages 21-55 years) with chronic (average 10 ± 6 years post-injury) severe (loss of consciousness 2-75 days) brain injury performed three trials of the Propriotest® on two separate days. The average of three trials and the best scores were used separately for analysis. Test-retest reliability was verified using Intraclass Correlation Coefficients with 95% confidence interval and standard error of measurement in relation to the Intraclass Correlation Coefficients at 95%. The minimal detectable change was calculated at 95% confidence level (minimal detectable change95) and Bland-Altman plots were created to express agreement between measurement days. RESULTS: The results exhibited excellent reliability for both average (Intraclass Correlation Coefficient of 0.969, standard error of measurement 50.9 points) and best (Intraclass Correlation Coefficient of 0.985, standard error of measurement 31.3 points) scores, with average and best minimal detectable change95 of 141.0 and 86.7 points, respectively. CONCLUSIONS: Clinicians and rehabilitation researchers can use these findings to determine if a Propriotest® change score represents a true post-treatment effect with adults with chronic brain injury.IMPLICATIONS FOR REHABILITATIONAfter brain injury, balance deficits are common and can persist well after completion of rehabilitation programs.Computerized dynamic posturography allows for objective quantification of one's capacity to respond to external perturbations.The device PROPRIO® 4000 provides reliable quantification of balance deficits of community dwelling individuals who have experienced a severe traumatic brain injury.The minimal detectable change scores created can assist clinicians and rehabilitation researchers detect whether a change in balance score represents a true effect of an intervention at post-treatment.

Feasibility of motor-assisted elliptical to improve walking, fitness and balance following pediatric acquired brain injury: A case series.

PURPOSE: Walking, fitness, and balance deficits are common following acquired brain injury (ABI). This study assessed feasibility, acceptability, and usefulness of a modified motor-assisted elliptical (ICARE) in addressing walking, fitness, and balance deficits in children with chronic ABIs. METHODS: Three children (> 5 years post-ABI) completed 24 ICARE exercise sessions (exercise time, speed, and time overriding motor-assistance gradually increased) to promote mass repetition of gait-like movements and challenge cardiorespiratory fitness. Parents' and children's perceptions of ICARE's safety, comfort, workout, and usability were assessed. Cardiovascular response, gait and balance outcomes were assessed. RESULTS: No adverse events occurred. Parent's Visual Analogue Scale (VAS) scores of perceived device safety (range 80-99), workout (range 99-100), and usability (range 75-100) were high, while comfort were 76-80 given commercial harness fit and arm support. Children's VAS scores all exceeded 89. Comfortable walking velocity, 2-Minute Walk Test, fitness, and Pediatric Balance Scale scores improved post-training, with many outcomes surpassing established minimal clinically important differences. CONCLUSION: Following engagement in moderate- to vigorous-intensity exercise promoting repetitive step-like movements on a specially adapted motor-assisted elliptical, three children with chronic ABI demonstrated improvements in walking, fitness and balance. Future research in community-based environments with a larger cohort of children with ABI is needed.

Variations in plantar pressure variables across elliptical trainers in older adults.

BACKGROUND: Ellipticals are used to address walking and cardiorespiratory training goals of older adults, some of whom are at risk for foot injuries. Variations in joint kinematics and muscle demands when using different ellipticals could lead to plantar pressure differences. This study explored plantar pressure variables during gait and use of four ellipticals. METHODS: Plantar pressures were recorded while 10 adults [68.1 (4.5) years] walked and used the True, Octane, Life Fitness, and SportsArt ellipticals. Repeated-measures ANOVAs (5 × 1) identified forefoot and heel differences across conditions. FINDINGS: Maximum forefoot forces and peak pressures were significantly lower than walking for each elliptical condition with one exception (Life Fitness peak pressure). However, sustained elliptical pedal contact time contributed to forefoot pressure-time integrals and dosages (i.e., cumulative pressure during one minute of activity) not varying significantly amongst elliptical and walking conditions. Heel maximum forces and peak pressures were significantly lower than walking during all elliptical conditions except SportsArt. Heel contact time on SportsArt and Octane exceeded walking, and SportsArt heel contact time exceeded Life Fitness. Heel pressure-time integral was greater on SportsArt compared to walking, Life Fitness, and True. Sports Art heel dosage exceeded Life Fitness and True. INTERPRETATION: While elliptical training's sustained double limb support diminished maximal forces and peak pressures under the forefoot and heel compared to walking, each ellipticals' pressure-time integral and dosage were not significantly lower than walking. These findings point to the importance of carefully initiating elliptical training programs to minimize tissue injury, particularly if sensory neuropathy is present.

Comparison of plantar pressure profile of young adults during training on elliptical devices and overground walking: A pilot study.

BACKGROUND: Elliptical training may offer advantages over other cardiorespiratory exercises for those requiring podiatric care, since its constant double-limb support diminishes recurring high-impact plantar forces while allowing exercise in a functional, upright posture. Unknown is the impact of distinct elliptical models, that can alter user's body mechanics, on potential variations in plantar pressure patterns. PURPOSE: To compare plantar pressure variables while exercising on four ellipticals and walking. METHODS: For this cross-sectional pilot study, plantar pressure data were recorded from ten young adults while exercising on four ellipticals (True, Octane, Life Fitness, SportsArt) and walking overground. One-way repeated measures ANOVA identified differences in heel, arch, and forefoot maximum force (MF), peak pressure (PP), and pressure-time integral (PTI). RESULTS: MF was lower under the heel when exercising on all ellipticals compared with walking, with further differences detected between models. PP was lower on all three foot regions when exercising on all ellipticals compared with walking, except Octane under the arch, with differences detected between ellipticals under the heel. PTI was lower under the heel and arch when exercising on some of the ellipticals compared with walking, with differences again detected under the heel between models. CONCLUSION: Plantar pressures were lower when exercising on the ellipticals compared with walking for most variables. Caution is recommended to which elliptical could be incorporated into therapeutic programs given that differences among models were detected under the heel.

Effect of motor-assisted elliptical training speed and body weight support on center of pressure movement variability.

BACKGROUND: A motor-assisted elliptical trainer is being used clinically to help individuals with physical disabilities regain and/or retain walking ability and cardiorespiratory fitness. Unknown is how the device's training parameters can be used to optimize movement variability and regularity. This study examined the effect of motor-assisted elliptical training speed as well as body weight support (BWS) on center of pressure (CoP) movement variability and regularity during training. METHODS: CoP was recorded using in-shoe pressure insoles as participants motor-assisted elliptical trained at three speeds (20, 40 and 60 cycles per minute) each performed at four BWS levels (0 %, 20 %, 40 %, and 60 %). Separate two-way repeated measures ANOVAs (3 × 4) evaluated impact of training speed and BWS on linear variability (standard deviation) and non-linear regularity (sample entropy) of CoP excursion (anterior-posterior, medial-lateral) for 10 dominant limb strides. FINDINGS: Training speed and BWS did not significantly affect the linear variability of CoP in the anterior-posterior or medial-lateral directions. However, sample entropy in both directions revealed the main effect of training speed (p < 0.0001), and a main effect of BWS was observed in the medial-lateral direction (p = 0.004). Faster training speeds and greater levels of BWS resulted in more irregular CoP patterns. INTERPRETATION: The finding that speed and BWS can be used to manipulate CoP movement variability when using a motor-assisted elliptical has significant clinical implications for promoting/restoring walking capacity. Further research is required to determine the impact of motor-assisted elliptical speed and BWS manipulations on functional recovery of walking in individuals who have experienced a neurologic injury or illness.

Therapeutic massage to enhance family caregivers' well-being in a rehabilitation hospital.

BACKGROUND AND PURPOSE: A massage therapy program was implemented to address the psychological well-being of family caregivers to patients in a rehabilitation hospital. The impact of massage "dosage" on caregiver stress and psychological well-being was examined in this study. Participants' perspectives on the program were also explored. MATERIALS AND METHODS: Thirty-eight family caregivers were randomized to receive either one massage per week or three massages per week for two weeks. Caregivers reported psychological symptoms and stress pre- and post-program. Program acceptability was assessed via responses on an exit survey. RESULTS: Overall, 79% of massages were received (89% among program completers). Post-program symptom scores were lower than baseline scores for both groups (F (1, 31) = 8.74 - 24.50, P < 0.01). Exit surveys indicated high program acceptability and perceived benefits. CONCLUSION: Findings suggest that massage services would be welcomed, utilized, and beneficial for improving the psychological well-being of family caregivers in a rehabilitation hospital.

Kinematic and muscle demand similarities between motor-assisted elliptical training and walking: Implications for pediatric gait rehabilitation.

Many children with physical disabilities and special health care needs experience barriers to accessing effective therapeutic technologies to improve walking and fitness in healthcare and community environments. The expense of many robotic and exoskeleton technologies hinders widespread use in most clinics, school settings, and fitness facilities. A motor-assisted elliptical trainer that is being used to address walking and fitness deficits in adults was modified to enable children as young as three years of age to access the technology (Pedi-ICARE). We compared children's kinematic and muscle activation patterns during walking and training on the Pedi-ICARE. Eighteen children walked (self-selected comfortable speed), Pedi-ICARE trained with motor-assistance at self-selected comfortable speed (AAC), and trained while over-riding motor-assistance (AAC+). Coefficient of multiple correlations (CMCs) compared lower extremity kinematic profiles during AAC and AAC+ to gait. Repeated measures ANOVAs identified muscle demand differences across conditions. CMCs revealed strong similarities at the hip and knee between each motor-assisted elliptical condition and gait. Ankle CMCs were only moderate. Muscle demands were generally lowest during AAC. Over-riding the motor increased hip and knee muscle demands. The similarity of motion patterns between Pedi-ICARE conditions and walking suggest the device could be used to promote task-specific training to improve walking. The capacity to manipulate muscle demands using different motor-assistance conditions highlights Pedi-ICARE's versatility in addressing a wide range of children's abilities.

Partial body weight support treadmill training speed influences paretic and non-paretic leg muscle activation, stride characteristics, and ratings of perceived exertion during acute stroke rehabilitation.

BACKGROUND: Intensive task-specific training is promoted as one approach for facilitating neural plastic brain changes and associated motor behavior gains following neurologic injury. Partial body weight support treadmill training (PBWSTT), is one task-specific approach frequently used to improve walking during the acute period of stroke recovery (<1month post infarct). However, only limited data have been published regarding the relationship between training parameters and physiologic demands during this early recovery phase. OBJECTIVE: To examine the impact of four walking speeds on stride characteristics, lower extremity muscle demands (both paretic and non-paretic), Borg ratings of perceived exertion (RPE), and blood pressure. DESIGN: A prospective, repeated measures design was used. METHODS: Ten inpatients post unilateral stroke participated. Following three familiarization sessions, participants engaged in PBWSTT at four predetermined speeds (0.5, 1.0, 1.5 and 2.0mph) while bilateral electromyographic and stride characteristic data were recorded. RPE was evaluated immediately following each trial. RESULTS: Stride length, cadence, and paretic single limb support increased with faster walking speeds (p⩽0.001), while non-paretic single limb support remained nearly constant. Faster walking resulted in greater peak and mean muscle activation in the paretic medial hamstrings, vastus lateralis and medial gastrocnemius, and non-paretic medial gastrocnemius (p⩽0.001). RPE also was greatest at the fastest compared to two slowest speeds (p<0.05). CONCLUSIONS: During the acute phase of stroke recovery, PBWSTT at the fastest speed (2.0mph) promoted practice of a more optimal gait pattern with greater intensity of effort as evidenced by the longer stride length, increased between-limb symmetry, greater muscle activation, and higher RPE compared to training at the slowest speeds.

Comparative analysis of speed's impact on muscle demands during partial body weight support motor-assisted elliptical training.

Individuals with walking limitations often experience challenges engaging in functionally relevant exercise. An adapted elliptical trainer (motor to assist pedal movement, integrated body weight harness, ramps/stairs, and grab rails) has been developed to help individuals with physical disabilities and chronic conditions regain/retain walking capacity and fitness. However, limited published studies are available to guide therapeutic interventions. This repeated measures study examined the influence of motor-assisted elliptical training speed on lower extremity muscle demands at four body weight support (BWS) levels commonly used therapeutically for walking. Electromyography (EMG) and pedal trajectory data were recorded as ten individuals without known disability used the motor-assisted elliptical trainer at three speeds [20,40, 60 revolutions per minute (RPM)] during each BWS level (0%, 20%, 40%, 60%). Overall, the EMG activity (peak, mean, duration) in key stabilizer muscles (i.e., gluteus medius, gluteus maximus, vastus lateralis, medial gastrocnemius and soleus) recorded at 60 RPM exceeded those at 40 RPM, which were higher than values at 20 RPM in all but three situations (gluteus medius mean at 0% BWS, vastus lateralis mean at 20% BWS, soleus duration at 40% BWS); however, these differences did not always achieve statistical significance. Slower motor-assisted speeds can be used to accommodate weakness of gluteus medius, gluteus maximus, vastus lateralis, medial gastrocnemius and soleus. As strength improves, training at faster motor-assisted speeds may provide a means to progressively challenge key lower extremity stabilizers.

Comparative kinematic and electromyographic assessment of clinician- and device-assisted sit-to-stand transfers in patients with stroke.

BACKGROUND: Workplace injuries from patient handling are prevalent. With the adoption of no-lift policies, sit-to-stand transfer devices have emerged as one tool to combat injuries. However, the therapeutic value associated with sit-to-stand transfers with the use of an assistive apparatus cannot be determined due to a lack of evidence-based data. OBJECTIVE: The aim of this study was to compare clinician-assisted, device-assisted, and the combination of clinician- and device-assisted sit-to-stand transfers in individuals who recently had a stroke. DESIGN: This cross-sectional, controlled laboratory study used a repeated-measures design. METHODS: The duration, joint kinematics, and muscle activity of 4 sit-to-stand transfer conditions were compared for 10 patients with stroke. Each patient performed 4 randomized sit-to-stand transfer conditions: clinician-assisted, device-assisted with no patient effort, device-assisted with the patient's best effort, and device- and clinician-assisted. RESULTS: Device-assisted transfers took nearly twice as long as clinician-assisted transfers. Hip and knee joint movement patterns were similar across all conditions. Forward trunk flexion was lacking and ankle motion was restrained during device-assisted transfers. Encouragement and guidance from the clinician during device-assisted transfers led to increased lower extremity muscle activation levels. LIMITATIONS: One lifting device and one clinician were evaluated. Clinician effort could not be controlled. CONCLUSIONS: Lack of forward trunk flexion and restrained ankle movement during device-assisted transfers may dissuade clinicians from selecting this device for use as a dedicated rehabilitation tool. However, with clinician encouragement, muscle activation increased, which suggests that it is possible to safely practice transfers while challenging key leg muscles essential for standing. Future sit-to-stand devices should promote safety for the patient and clinician and encourage a movement pattern that more closely mimics normal sit-to-stand biomechanics.

Monitoring cerebral hemodynamics with transcranial Doppler ultrasound during cognitive and exercise testing in adults following unilateral stroke.

An observational study was performed as a preliminary investigation into the use of transcranial Doppler ultrasound (TCD) for recording cerebral hemodynamic changes during multiple tasks. TCD is a method of measuring cerebral blood flow (CBF) using ultrasound transducers in contact with the surface of the head. Using the maximum flow envelope of the Doppler spectrum returning from the middle cerebral artery (MCA), standard clinical flow indices can be calculated and displayed in real time providing information concerning perturbations in CBF and their potential cause. These indices as well as flow velocity measurements have been recognized as useful in measuring changes in responses to various stimulus that can be used to indicate cardiovascular health. For this study, the pulsatility index (PI) and resistivity index (RI) were chosen since they indicate composite changes indicative of vasoconstriction and vasodilatation which are normal hemodynamic responses under appropriate conditions. A total of eleven participants were recruited to take part in this study. Nine of these individuals had no known disability (Controls); two had experienced unilateral cerebrovascular accidents (Strokes) in the ipsilateral MCA distribution. Maximum velocity envelopes of the spectral Doppler data were recorded using a fixation device designed to stabilize two ultrasound probes (2 MHz) to sample the bilateral MCAs CBF. These measures were performed separately while the subject performed four activities: 1) rest, 2) cognitive challenge, 3) cardiovascular exercise, and 4) simultaneous exercise and cognitive challenge. Cardiovascular parameters were calculated from the data by extracting maximum (Vs) and minimum flow velocities (Vd), PI, RI, and time signatures for each cardiac cycle. The data for all participants shows significant changes in cardiovascular parameters between states of rest and exercise, as well as slight trends across time. Although the data are preliminary, they show the capability of using Doppler spectral examination of the bilateral MCAs in individuals with physical limitation performing cardiovascular exercise. The novelty of examining a population using dynamic exercise who before could not perform such exercise offers the opportunity to study the impact of exercise on global cerebral recovery in unilateral stroke with significant physical impairment.

Kinematic and electromyographic analyses of normal and device-assisted sit-to-stand transfers.

Mechanical sit-to-stand devices assist patient transfers and help protect against work-related injuries in rehabilitation environments. However, observational differences between patient's movements within devices compared to normal sit-to-stand transfers deter clinician use. This study compared kinematics and muscle demands during sit-to-stand transfers with no device (ND), and device-assisted during which participants exerted no effort (DA-NE) and best effort (DA-BE). Coefficient of multiple correlations (CMCs) compared kinematic profiles during each device-assisted condition to ND. Compared to DA-NE, CMCs were higher during DA-BE at the hip, knee, and ankle. However, DA-BE values were lower than DA-NE at the trunk and pelvis due to the device's mechanical constraints. In general, all joints' final DA-NE postures were more flexed than other conditions. Electromyographic was significantly lower during DA-NE compared to ND for all muscles except lateral hamstring, and during DA-BE compared to ND for gluteus maximus, gastrocnemius, and soleus. Verbal encouragement (DA-BE) significantly increased medial hamstring, vastus lateralis, gastrocnemius, soleus and tibialis anterior activation compared to DA-NE. In conclusion, device-assisted sit-to-stand movements differed from normal sit-to-stand patterns. Verbally encouraging best effort during device-assisted transfers elevated select lower extremity muscle activation and led to greater similarity in hip, knee and ankle movement profiles. However, trunk and pelvis profiles declined.

Impact of elliptical trainer ergonomic modifications on perceptions of safety, comfort, workout, and usability for people with physical disabilities and chronic conditions.

BACKGROUND: The popularity of elliptical training has grown in rehabilitation, fitness, and home settings as a means for improving fitness and walking, yet many people with physical disabilities and chronic conditions experience difficulties when trying to use elliptical trainers. OBJECTIVE: The purpose of this study was to compare, for people with disabilities and chronic conditions, perceptions of safety, comfort, workout, and usability of 4 elliptical trainers before and after the development of a set of low-cost adaptations. DESIGN: This study was a quasi-experimental repeated-measures investigation. METHODS: Twenty adults with diverse medical conditions and functional abilities evaluated 4 elliptical trainers for safety, comfort, workout, and usability. Barriers to the use of the elliptical trainers and solutions to improve the use of the trainers were identified. Prototype modifications were designed, and participants reassessed the same features after the modifications were made. RESULTS: An integrated system (steps, bench, side rails, center rail or handle, deeper foot wells, and 1-handed heart rate monitor) was developed. Although at least 25% of participants required physical assistance to get on or off the elliptical trainers before modification, only one required this after modification. Before modification, only 1 participant was able to mount each device independently; after modification, 6 to 8 participants were able to do so. Up to 25% of participants continued to require assistance to initiate or sustain pedal movement. Compared with participants' ratings of the elliptical trainers before modification, those after modification were higher for safety (55% increase in visual analog scale ratings), comfort (43% higher), ability to achieve a good workout (23% greater), and usability (24% increase). LIMITATIONS: To date, only 4 elliptical trainers have been studied with a small sample of convenience. CONCLUSIONS: Elliptical trainers posed access challenges to people with disabilities, chronic conditions, or both. Implementation of low-cost modifications successfully reduced barriers and the need for assistance, enabling greater access for people who could benefit from using the devices for functional training and fitness.