Survey-based identification of design requirements and constraints for a wearable tremor suppression device.

Introduction: Parkinsonian tremor has severely impacted the lives of 65% of individuals with Parkinson's disease, and nearly 25% do not respond to traditional treatments. Although wearable tremor suppression devices (WTSDs) have become a promising alternative approach, this technology is still in the early stages of development, and no studies have reported the stakeholders' opinions on this technology and their desired design requirements. Methods: An online survey was distributed to affected Canadians and Canadian movement disorder specialists (MDS) to acquire information on demographics, the current state of treatments, opinions on the WTSDs, and the desired design requirements of future WTSDs. Results: A total of 101 affected individuals and 24 MDS completed the survey. It was found that both groups are generally open to using WTSDs to manage tremor. The most important design requirement to end users is the adaptability to lifestyle, followed by weight and size, accurate motion, comfort, safety, quick response, and cost. Lastly, most of the participants (65%) think that the device should cost under $500. Conclusions: The findings from this study can be used as guidelines for the development of future WTSDs, such that the future generations could be evaluated and accepted by the end users.

Scalene and sternocleidomastoid activation during normoxic and hypoxic incremental inspiratory loading.

The purpose of this study was to examine scalene (SA) and sternocleidomastoid (SM) activation during normoxic (norm-ITL; FIO2  = 21%) and hypoxic (hyp-ITL; FIO2  = 15%) incremental inspiratory threshold loading (ITL). Thirteen healthy participants (33 ± 4 years, 9 female) performed two ITL tests breathing randomly assigned gas mixtures through an inspiratory loading device where the load was increased every two minutes until task failure. SA and SM root mean square (RMS) electromyography (EMG) were calculated and expressed as a percentage of maximum (RMS%max ) to reflect muscle activation intensity. Myoelectric manifestations of fatigue were characterized as decreased SA or SM EMG median frequency during maximum inspiratory pressure maneuvers before and after ITL. Dyspnea was recorded at baseline and task failure. Ventilatory parameters and mouth pressure (Pm) were recorded throughout the ITL. SA,RMS%max and SM,RMS%max increased in association with ITL load (p ≤ .01 for both). SA,RMS%max was similar between norm-ITL and hyp-ITL (p = .17), whereas SM,RMS%max was greater during the latter (p = .001). Neither SA nor SM had a decrease in EMG median frequency after ITL (p = .75 and 0.69 respectively). Pm increased in association with ITL load (p < .001) and tended to be higher during hyp-ITL compared to norm-ITL (p = .05). Dyspnea was similar during both conditions (p > .05). There was a trend for higher tidal volumes during hyp-ITL compared to norm-ITL (p = .10). Minute ventilation was similar between both conditions (p = .23). RMS,%max of the SA and SM increased linearly with increasing ITL. The presence of hypoxia only increased SM activation. Neither SA nor SM presented myoelectric manifestations of fatigue during both conditions.

Modeling health-related quality of life in people recovering from stroke.

BACKGROUND: The Wilson-Cleary (W-C) model of health-related quality of life (HRQL) has not been tested in stroke, and a better understanding of the components of HRQL during recovery would lead to a more integrated and person-centered approach to health management and outcome optimization for this vulnerable population. OBJECTIVE: To enhance our understanding for how QOL emerges from the sequelae of stroke during the recovery period, the aim was to empirically test a biopsychosocial conceptual model of HRQL for people recovering from stroke. METHODS: We present a multi-site longitudinal study of an inception cohort of 678 persons recruited at stroke onset and studied at key intervals over the first post-stroke year. As the most pronounced recovery after stroke occurs in the first 3 months, this time frame was chosen as the focus of this analysis. The measures for this study were chosen for their relevance to key constructs of stroke impact and for their optimal psychometric properties. Multiple measures for each of the W-C rubrics were available from instruments such as the Stroke Impact Scale, RAND-36, HUI, and EQ-5D, among others. A structural equation model (SEM) was fit using MPlus. To minimize potential bias arising from the missing data, multiple imputation was performed on the longitudinal data using SAS proc MI. RESULTS: Of the 678 subjects who entered the cohort, 618 were interviewed at 1 month post-stroke and 533 at 3 months (486 and 454 had data at 6 and 12 months, respectively). A 3-month model with paths from biological factors to symptoms and symptoms to function fits well (CFI:0.966, RMSEA:0.044), though one model with paths from function to health perception did not (CFI:0.934, RMSEA:0.058). Allowing additional paths across non-adjacent rubrics improved fit considerably (CFI:0.962, RMSEA:0.044). A final model included emotional well-being under the symptom rubric (CFI:0.955, RMSEA:0.047). Including social support as an environmental factor had little impact on the model. Total variance in health perception explained was 76.3 %. CONCLUSION: These results emphasize that to optimize overall HRQL during the crucial first 3 months of recovery, interventions need to continue to focus on comorbid health conditions and on reducing stroke impairments. A function-only focus too soon in the recovery process may not produce the desired impact to optimize HRQL.

Moments and muscle activity after high tibial osteotomy and anterior cruciate ligament reconstruction.

PURPOSES: To evaluate the effects of simultaneous high tibial osteotomy (HTO) and anterior cruciate ligament (ACL) reconstruction on 1) the external knee adduction moment, 2) the external knee flexion and extension moments, and 3) the quadriceps, hamstrings, and gastrocnemius muscle activity during walking. METHODS: Twenty-one patients with varus malalignment of the lower limb, medial compartment knee osteoarthritis, and concomitant anterior cruciate ligament (ACL) deficiency were tested before and 1 yr after undergoing simultaneous medial opening wedge high tibial osteotomy (HTO) and ACL reconstruction during a single operation. Three-dimensional kinetic and kinematic data were used to calculate external coronal and sagittal moments about the knee. EMG data from the quadriceps, hamstrings, and gastrocnemius were used to determine coactivation ratio and activation patterns. RESULTS: Neutral alignment and knee stability were achieved in all patients after surgery. The peak knee adduction moment decreased from 2.88 +/- 0.57 to 1.71 +/- 0.56%BW x Ht (P < 0.001). The early stance knee flexion moment decreased from 1.95 +/- 1.89 to 0.88 +/- 1.17%BW x Ht (P < 0.01). The late stance knee extension moment increased from 1.83 +/- 1.53 to 2.76 +/- 1.22%BW x Ht (P < 0.001). There were no significant differences in muscle coactivation or muscle activation patterns (P > 0.05). CONCLUSIONS: Improving lower limb alignment and knee stability significantly alters the coronal and the sagittal moments about the knee during walking, without apparent changes in muscle activation patterns.

Mobility assistive device utilization in a prospective study of patients with first-ever stroke.

OBJECTIVE: To estimate the extent to which clinical and functional features of stroke were related to the use of mobility assistive technology devices. DESIGN: Longitudinal study of quality of life after stroke. SETTING: Hospitals, rehabilitation centers, and universities in Ontario and Quebec. PARTICIPANTS: Subjects (N=316) with confirmed initial stroke were included in this analysis. Fifty-eight percent of the overall sample were men (n=184). The mean age of this sample at the time of the stroke +/- standard deviation was 65.3+/-15.3 years (range, 19-96y). One hundred thirty-five patients received a mobility assistive device poststroke, and 181 did not. INTERVENTION: Assistive devices for mobility (canes, walkers, wheelchairs). MAIN OUTCOME MEASURES: Assistive device use and mobility capacity. RESULTS: Mobility device nonusers were less physically disabled than device users on a variety of measures. Poor physical functioning but good cognition were reliably associated with mobility device use. Use of multiple mobility assistive devices was more often associated with poorer physical functioning than was single device use. For single device users, wheelchair use was predicted by cognition, functional independence, and stroke recovery. Cane users, compared with walker users, had better mobility and were less physically impaired by stroke. CONCLUSIONS: Patients were well matched to device type based on their mobility capacity. The findings of this study suggest that assistive device prescription-outcome relationships in stroke can be effectively and meaningfully modeled.