Why do some people who had a stroke not receive the recommended 45 min of occupational therapy and physiotherapy? A Delphi study.

OBJECTIVES: To gain a consensus among therapists for reasons why a person who had a stroke may not receive the Royal College of Physicians' recommended minimum of 45 min of daily therapy. DESIGN: Three-round remote e-Delphi study. SETTING: National study, based in the UK. PARTICIPANTS: Occupational therapists and physiotherapists with experience of delivering therapy after stroke and awareness of the 45 min guideline. RESULTS: Forty-five therapists consented to participate in the study. Thirty-five (78%) completed round one, 29 of 35 (83%) completed round 2 and 26 of 29 (90%) completed round three. A consensus (75%) was reached for 32 statements. Reasons why a person may not receive 45 min were related to the suitability of the guideline for the individual (based on factors like therapy tolerance or medical status) or the capability of the service to provide the intervention. In addition to the statements for which there was a consensus, 32 concepts did not reach a consensus. Specifically, there was a lack of consensus concerning the suitability of the guideline for people receiving Early Supported Discharge (ESD) services and a lack of agreement about whether people who need more than 45 min of therapy actually receive it. CONCLUSION: Some people do not receive 45 min of therapy as they are considered unsuitable for it and some do not receive it due to services' inability to provide it. It is unclear which reasons for guideline non-achievement are most common. Future research should focus on why the guideline is not achieved in ESD, and why people who require more than 45 min may not receive it. This could contribute to practical guidance for therapists to optimise therapy delivery for people after stroke.

Why do some people with stroke not receive the recommended 45 min of occupational therapy and physiotherapy after stroke? A qualitative study using focus groups.

OBJECTIVES: To generate qualitative data on the views of Occupational Therapists and Physiotherapists about why people do not receive the Royal College of Physicians' recommended minimum of 45 minutes (min) of daily therapy after stroke, in order to inform a Delphi study. DESIGN: Focus group study. SETTING: Stroke services in the South of England. PARTICIPANTS: A total of nine participants, in two groups, including therapists covering inpatient and Early Supported Discharge (ESD) services with awareness of the 45 min guideline. RESULTS: Thematic analysis of focus group data identified five factors that influence the amount of therapy a person receives: The Person (with stroke), Individual Therapist, Stroke Multidisciplinary Team, the Organisation and the Guideline. Study findings suggest that the reasons why a person does not receive the therapy recommendation in inpatient and ESD services relate to either the suitability of the guideline for the person with stroke, or the ability of the service to deliver the guideline. CONCLUSION: This study provides evidence for possible reasons why some people do not receive a minimum of 45 minutes of therapy, 5 days per week, related to (1) the suitability of the guideline for people with stroke and (2) services' ability to deliver this amount of intervention. These two factors are related; therapists decide who should receive therapy and how much in the context of (a) resource availability and (b) people's need and the benefit they will experience. The study findings, combined with the findings from other studies, will be used to initiate a Delphi study, which will establish consensus among therapists regarding the reasons why some people do not receive the guideline amount of therapy.

Preparing allied health students for placement: a contrast of learning modalities for foundational skill development.

BACKGROUND: With increasing pressure on placement capacity for allied health students, a need for novel and creative means through which students can develop foundational skills and prepare for practice-based learning opportunities has arisen. This study aimed to explore the experiences of domestic and international first-year students completing pre-clinical preparation programs, contrasting between in-person simulation and online options to contribute to best practice evidence for program design and delivery. METHODS: First-year students from physiotherapy, podiatry and occupational therapy self-selected to either a one-weeklong in-person simulation program or an online preparation for placement program. An integrative mixed-methods approach was employed. Qualitative findings from student focus groups were analyzed by reflexive thematic analysis and complemented by quantitative pre-post questionnaires which were examined for patterns of findings. RESULTS: There were 53 student participants in the study (simulation n = 29; online n = 24). Self-selecting, international students disproportionately opted for the simulation program while older students disproportionately selected the online program. Students appeared to benefit more from the simulation program than the online program, with alignment of focus group findings to the quantitative questionnaire data. The in-person simulation allowed students to apply their learning and practice patient communication. All simulation students reported asubsequent increase in confidence, although this seemed particularly marked for the international students. By contrast, the online program was most effective at developing students' clinical reasoning and proficiency with documentation. Both programs faced minor challenges to student perceived relevance and skill development. CONCLUSION: Both online and in-person simulation preparation programs were perceived to enhance readiness and foundational skills development for novice allied health students, with the practical nature of simulation generating more advantageous findings. This study provides useful information on the benefits and challenges of both types of delivery for foundational skills development and/or clinical preparation of allied health students.

Task selection for a sensor-based, wearable, upper limb training device for stroke survivors: a multi-stage approach.

PURPOSE: Post-stroke survivors report that feedback helps to increase training motivation. A wearable system (M-MARK), comprising movement and muscle sensors and providing feedback when performing everyday tasks was developed. The objective reported here was to create an evidence-based set of upper-limb tasks for use with the system. MATERIALS AND METHODS: Data from two focus groups with rehabilitation professionals, ten interviews with stroke survivors and a review of assessment tests were synthesized. In a two-stage process, suggested tasks were screened to exclude non-tasks and complex activities. Remaining tasks were screened for suitability and entered into a categorization matrix. RESULTS: Of 83 suggestions, eight non-tasks, and 42 complex activities were rejected. Of the remaining 33 tasks, 15 were rejected: five required fine motor control; eight were too complex to standardize; one because the role of hemiplegic hand was not defined and one involved water. The review of clinical assessment tests found no additional tasks. Eleven were ultimately selected for testing with M-Mark. CONCLUSIONS: Using a task categorization matrix, a set of training tasks was systematically identified. There was strong agreement between data from the professionals, survivors and literature. The matrix populated by tasks has potential for wider use in upper-limb stroke rehabilitation. IMPLICATIONS FOR REHABILITATIONRehabilitation technologies that provide feedback on quantity and quality of movements can support independent home-based upper limb rehabilitation.Rehabilitation technology systems require a library of upper limb tasks at different levels for people with stroke and therapists to choose from.A user-defined and evidence-based set of upper limb tasks for use within a wearable sensor device system have been developed.

Validity and reliability of sensor system to measure trunk range of motion during Streamlined Wolf Motor Function Test in chronic stroke and aged-matched healthy participants.

OBJECTIVE: To investigate the validity and reliability of using the Valedo® system to measure trunk Range of Motion (ROM) during performance of the streamlined Wolf Motor Function Test (SWMFT). METHODS: Twenty chronic strokes and 20 age-matched healthy participants performed SWMFT while wearing Valedo® sensors on their trunks to capture trunk movements. A paired sample T-test was used to examine the validity of the system in distinguishing between the healthy and stroke group, and between the affected and unaffected sides in the stroke group. Interclass correlation coefficients were used to assess the inter-rater and intra-rater reliability (between-days) with 95% CI. RESULTS: The Valedo® system was able to distinguish between stroke and healthy participants; stroke participants employed greater trunk range of movements than the healthy controls in all tasks (p < .01). Furthermore, the Valedo® system enabled differentiation between affected and unaffected hands of people within the stroke group. The reliability for the stroke group was good to excellent with intrarater reliability (ICC = 0.71-0.92) and interrater reliability (ICC = 0.63-0.95). CONCLUSIONS: The Valedo system demonstrates an acceptable level of validity and reliability for measuring trunk ROM during the Streamlined Wolf Motor Function Test (SWMFT). Future studies with a larger sample size, different levels of upper limb impairment are warranted.

Instrumented trunk impairment scale (iTIS): A reliable measure of trunk impairment in the stroke population.

BACKGROUND: The Trunk Impairment Scale (TIS) is recommended for use in clinical research to assess trunk impairment post-stroke. However, it is observer dependent and does not consider the quality of trunk movement. To address these challenges, this study proposes an instrumented TIS (iTIS). OBJECTIVE: This study aims to investigate the intra-rater and inter-rater reliability of the iTIS in chronic stroke patients. METHOD: Trunk impairment was assessed in 20 patients with stroke using the iTIS Valedo system; three sensors were fixed to the skin on the sternum, L1 and S1 levels. Interclass correlation coefficients were used to assess the inter-rater and intra-rater reliability (between days) with 95% CI. RESULTS: Reliability for the dynamic subscale parameters was good to excellent (intra-rater ICC = 0.60-0.95; inter-rater ICC = 0.59-0.93); however, reliability for the coordination parameters was poor to good (intra-rater ICC = 0.05-0.72) and poor to excellent (inter-rater ICC = 0.04-0.78). CONCLUSION: The iTIS demonstrates an acceptable level of reliability for dynamic subscale measurement in research and clinical practice. Further studies could use larger sample sizes and improve the iTIS methodology by employing additional sensors on the limbs to detect compensatory movements.

New advances in mechanomyography sensor technology and signal processing: Validity and intrarater reliability of recordings from muscle.

INTRODUCTION: The Mechanical Muscle Activity with Real-time Kinematics project aims to develop a device incorporating wearable sensors for arm rehabilitation following stroke. These will record kinematic activity using inertial measurement units and mechanical muscle activity. The gold standard for measuring muscle activity is electromyography; however, mechanomyography offers an appropriate alterative for our home-based rehabilitation device. We have patent filed a new laboratory-tested device that combines an inertial measurement unit with mechanomyography. We report on the validity and reliability of the mechanomyography against electromyography sensors. METHODS: In 18 healthy adults (27-82 years), mechanomyography and electromyography recordings were taken from the forearm flexor and extensor muscles during voluntary contractions. Isometric contractions were performed at different percentages of maximal force to examine the validity of mechanomyography. Root-mean-square of mechanomyography and electromyography was measured during 1 s epocs of isometric flexion and extension. Dynamic contractions were recorded during a tracking task on two days, one week apart, to examine reliability of muscle onset timing. RESULTS: Reliability of mechanomyography onset was high (intraclass correlation coefficient = 0.78) and was comparable with electromyography (intraclass correlation coefficient = 0.79). The correlation between force and mechanomyography was high (R2 = 0.94). CONCLUSION: The mechanomyography device records valid and reliable signals of mechanical muscle activity on different days.

Concurrent Validity of a Novel Wireless Inertial Measurement System for Assessing Trunk Impairment in People with Stroke.

Background: The Trunk Impairment Scale (TIS) is recommended for clinical research use to assess trunk impairment post-stroke. However, it is observer-dependent and neglects the quality of trunk movements. This study proposes an instrumented TIS (iTIS) using the Valedo system, comprising portable inertial sensors, as an objective measure of trunk impairment post-stroke. Objective: This study investigates the concurrent and discriminant ability of the iTIS in chronic stroke participants. Method: Forty participants (20 with chronic stroke, 20 healthy, age-matched) were assessed using the TIS and iTIS simultaneously. A Spearman rank correlation coefficient was used to examine concurrent validity. A ROC curve was used to determine whether the iTIS could distinguish between stroke participants with and without trunk impairment. Results: A moderate relationship was found between the observed iTIS parameters and the clinical scores, supporting the concurrent validity of the iTIS. The small sample size meant definitive conclusions could not be drawn about the parameter differences between stroke groups (participants scoring zero and one on the clinical TIS) and the parameter cut-off points. Conclusion: The iTIS can detect small changes in trunk ROM that cannot be observed clinically. The iTIS has important implications for objective assessments of trunk impairment in clinical practice.

Rehab-Net: Deep Learning Framework for Arm Movement Classification Using Wearable Sensors for Stroke Rehabilitation.

In this paper, we present a deep learning framework "Rehab-Net" for effectively classifying three upper limb movements of the human arm, involving extension, flexion, and rotation of the forearm, which, over the time, could provide a measure of rehabilitation progress. The proposed framework, Rehab-Net is formulated with a personalized, light weight and low-complex, customized convolutional neural network (CNN) model, using two-layers of CNN, interleaved with pooling layers, followed by a fully connected layer that classifies the three movements from tri-axial acceleration input data collected from the wrist. The proposed Rehab-Net framework was validated on sensor data collected in two situations: 1) semi-naturalistic environment involving an archetypal activity of "making-tea" with four stroke survivors and 2) natural environment, where ten stroke survivors were free to perform any desired arm movement for the duration of 120 min. We achieved an overall accuracy of 97.89% on semi-naturalistic data and 88.87% on naturalistic data which exceeded state-of-the-art learning algorithms namely, linear discriminant analysis, support vector machines, and k-means clustering with an average accuracy of 48.89%, 44.14%, and 27.64%. Subsequently, a computational complexity analysis of the proposed model has been discussed with an eye toward hardware implementation. The clinical significance of this study is to accurately monitor the clinical progress of the rehabilitated subjects under the ambulatory settings.

Do trunk exercises improve trunk and upper extremity performance, post stroke? A systematic review and meta-analysis.

BACKGROUND: Post-stroke trunk control is reported to be associated with trunk performance and recovery of the upper limb, but the evidence for the influence of trunk exercise on both of these is unclear. OBJECTIVE: To evaluate the effect of trunk exercises on trunk performance post-stroke, and to determine if these exercises result in improved upper limb function. METHODS: A comprehensive search of the literature published between January 1990 and February 2017 was conducted using the following electronic databases; AMED, CINAHL, Cochrane Library, EMBASE, MEDLINE, PsychInfo and SPORTDiscus. Only randomized, controlled trials, published in English, evaluating the effect of trunk exercises on trunk performance and/or upper limb function post-stroke, were included. RESULTS: A total of 17 studies involving 599 participants were analysed. Meta-analysis showed that trunk exercises had a large significant effect on trunk performance post-stroke. This effect varied from very large for acute stroke to medium for subacute and chronic stroke. None of the included studies had measured the effect of trunk exercise on upper limb impairment or functional activity. CONCLUSIONS: Trunk exercises improve trunk performance for people with acute, subacute and chronic strokes. As yet there is no evidence to support the effect of trunk exercise on upper limb function.

Telehealth, Wearable Sensors, and the Internet: Will They Improve Stroke Outcomes Through Increased Intensity of Therapy, Motivation, and Adherence to Rehabilitation Programs?

BACKGROUND AND PURPOSE: Stroke, predominantly a condition of older age, is a major cause of acquired disability in the global population and puts an increasing burden on health care resources. Clear evidence for the importance of intensity of therapy in optimizing functional outcomes is found in animal models, supported by neuroimaging and behavioral research, and strengthened by recent meta-analyses from multiple clinical trials. However, providing intensive therapy using conventional treatment paradigms is expensive and sometimes not feasible because of social and environmental factors. This article addresses the need for cost-effective increased intensity of practice and suggests potential benefits of telehealth (TH) as an innovative model of care in physical therapy. SUMMARY OF KEY POINTS: We provide an overview of TH and present evidence that a web-supported program, used in conjunction with constraint-induced therapy (CIT), can increase intensity and adherence to a rehabilitation regimen. The design and feasibility testing of this web-based program, "LifeCIT," is presented. We describe how wearable sensors can monitor activity and provide feedback to patients and therapists. The methodology for the development of a wearable device with embedded inertial and mechanomyographic sensors, algorithms to classify functional movement, and a graphical user interface to present meaningful data to patients to support a home exercise program is explained. RECOMMENDATIONS FOR CLINICAL PRACTICE: We propose that wearable sensor technologies and TH programs have the potential to provide most-effective, intensive, home-based stroke rehabilitation.

Translation of evidence-based Assistive Technologies into stroke rehabilitation: users' perceptions of the barriers and opportunities.

BACKGROUND: Assistive Technologies (ATs), defined as "electrical or mechanical devices designed to help people recover movement", demonstrate clinical benefits in upper limb stroke rehabilitation; however translation into clinical practice is poor. Uptake is dependent on a complex relationship between all stakeholders. Our aim was to understand patients', carers' (P&Cs) and healthcare professionals' (HCPs) experience and views of upper limb rehabilitation and ATs, to identify barriers and opportunities critical to the effective translation of ATs into clinical practice. This work was conducted in the UK, which has a state funded healthcare system, but the findings have relevance to all healthcare systems. METHODS: Two structurally comparable questionnaires, one for P&Cs and one for HCPs, were designed, piloted and completed anonymously. Wide distribution of the questionnaires provided data from HCPs with experience of stroke rehabilitation and P&Cs who had experience of stroke. Questionnaires were designed based on themes identified from four focus groups held with HCPs and P&Cs and piloted with a sample of HCPs (N = 24) and P&Cs (N = 8). Eight of whom (four HCPs and four P&Cs) had been involved in the development. RESULTS: 292 HCPs and 123 P&Cs questionnaires were analysed. 120 (41%) of HCP and 79 (64%) of P&C respondents had never used ATs. Most views were common to both groups, citing lack of information and access to ATs as the main reasons for not using them. Both HCPs (N = 53 [34%]) and P&C (N = 21 [47%]) cited Functional Electrical Stimulation (FES) as the most frequently used AT. Research evidence was rated by HCPs as the most important factor in the design of an ideal technology, yet ATs they used or prescribed were not supported by research evidence. P&Cs rated ease of set-up and comfort more highly. CONCLUSION: Key barriers to translation of ATs into clinical practice are lack of knowledge, education, awareness and access. Perceptions about arm rehabilitation post-stroke are similar between HCPs and P&Cs. Based on our findings, improvements in AT design, pragmatic clinical evaluation, better knowledge and awareness and improvement in provision of services will contribute to better and cost-effective upper limb stroke rehabilitation.

A personalized sensor-controlled microstimulator system for arm rehabilitation poststroke. Part 1: System architecture.

OBJECTIVES: For rehabilitation of the poststroke upper limb in seven subjects, an external sensor-based system controls the timing of five to seven microstimulators implanted near radial nerve branches or their motor points to sequentially extend the elbow, wrist, and fingers with thumb extension and abduction, enabled at the subject's own pace. We hypothesize this system will support sequential activation of affected upper limb muscles intended to improve functional recovery. MATERIALS AND METHODS: Presented here is a personalized sensor-controlled stimulation system, including its architecture, sensor design, and testing of equipment specific to this study, including coils and sensors. RESULTS: All electrical and magnetic tests, and safety tests per International Electrotechnical Commission 60601-1 passed. One sensor type displayed a vulnerability to drop. CONCLUSIONS: The new control system tested safe, met requirements, and allowed each subject to activate the system at their own pace, making the rehabilitation process more acceptable and efficient.

A personalized sensor-controlled microstimulator system for arm rehabilitation poststroke. Part 2: Objective outcomes and patients' perspectives.

OBJECTIVE: To examine the effect of home-based electrical stimulation using closed-loop control of implanted microstimulators on upper limb function and impairment, and subjects' perception of the system. MATERIALS AND METHODS: Six subjects with poststroke hemiparesis, and reduced upper limb function, who had taken part in Phase 1 of the study, were fitted with a personalized closed-loop control system (Phase 2) and used it at home during performance of functional tasks for 12 weeks (Phase 3). Main outcome measures were: Action Research Arm Test (ARAT), Fugl-Meyer upper limb assessment (FMA), and motor control (Tracking Index). Subjects' perception of the system was assessed in a structured interview. RESULTS: Improvement in ARAT (p=0.05), FMA (p=0.02), and Tracking Index (p=0.03) during Phase 3. Five subjects said using the system had changed their lives and improved their function, all performed functional tasks with the system, but external components were inconvenient. CONCLUSIONS: Closed-loop control improved in function. Subjective assessment identified that the external sensors were effective.

The relationship between upper limb activity and impairment in post-stroke hemiplegia.

PURPOSE: To investigate the relationship between upper limb impairments and activity limitation. METHOD: A cross sectional, single assessment observational study in which people with hemiplegia as a result of a stroke underwent a testing procedure in an instrumented wrist rig in which the following measures of impairment were recorded: Spasticity; motor control (ability to track a moving target); muscle activation patterns during tracking; stiffness; range of active movement and isometric muscle strength. Participants also performed clinical tests of upper limb activity (Action Research Arm Test) and hyper-tonicity (Modified Ashworth Scale). RESULTS: Seventeen people with hemiplegia whose mean age was 57 (SD 13.4) took part. Their mean upper limb activity, measured by the Action Research Arm Test, was 19.3 (SD 11.2). Statistically significant positive relationships between level of activity and the negative features of the upper motor neuron syndrome such as motor control r = 0.710 (p = 0.003), active range of movement r = 0.540 (p = 0.025) and strength into flexion r = 0.515 (p = 0.034) and extension r = 0.575 (p = 0.016) were identified, but not with the positive features, such as spasticity or the secondary features such as stiffness. CONCLUSIONS: The negative features of the upper motor neuron syndrome appear more likely to affect upper limb activity than the positive or secondary features, but findings need confirming in different study populations, preferably with larger samples.

Therapeutic effectiveness of electric stimulation of the upper-limb poststroke using implanted microstimulators.

OBJECTIVE: To investigate the therapeutic effect of functional exercise augmented by programmable implanted microstimulators on arm and hand function. DESIGN: Before and after study. SETTING: Implantation was performed in a neurosurgery unit, systems were programmed, and tests were conducted in a university laboratory and subjects exercised at home. PARTICIPANTS: Hemiparetic subjects (N=7) with reduced upper-limb function who were at least 12 months poststroke were recruited from the community. No subjects withdrew. INTERVENTION: Microstimulators were implanted into the arms and forearms to activate elbow, wrist, and finger extension, and thumb abduction. After training and programming of the system, subjects underwent 12 weeks of functional home-based exercise with stimulation. MAIN OUTCOME MEASURES: The primary functional measure was the Action Research Arm Test (ARAT). Impairment measures included upper-limb Fugl-Meyer Assessment (FMA) and tests of motor control (tracking index), spasticity (electromyography stretch index) strength, and active range of motion (AROM). The assessor was not blinded, but scores were validated by an independent blinded observer. RESULTS: All subjects were able to perform functional activities at home by using the system. Compliance was excellent, and there were no serious adverse events. Statistically significant improvements were measured (P<.05) in the tracking index (57.3 degrees(2)+/-48.65 degrees(2)), FMA score (6.3+/-3.59), wrist-extensor strength (5.5+/-4.37 N), and wrist AROM (19.3 degrees +/-18.96 degrees). The mean improvement in ARAT score +/- SD of 4.9+/-7.89 was not statistically significant. CONCLUSIONS: This study has shown the feasibility of a programmable implanted microstimulator system used at home to perform functional exercises and a reduction in impairment after 12 weeks.

Reliability and sensitivity of a wrist rig to measure motor control and spasticity in poststroke hemiplegia.

BACKGROUND: Objective assessment of impairments after stroke is vital for evidence-based therapy and progress monitoring. OBJECTIVE: This study determines the utility of outcome measures obtained from an instrumented wrist rig for future rehabilitation trials. The tests undertaken were evaluated in terms of sensitivity to detect differences between normal and impaired participants, test-retest repeatability (repeatability coefficient and intraclass correlation coefficient [ICC]), and interrater agreement (Bland and Altman limits of agreement). METHODS: Twelve participants with chronic poststroke hemiparesis (mean 5.6 years); and 12 unimpaired volunteers performed a series of tasks in the rig. The hemiparetic arm (impaired group) and dominant arm (unimpaired group) were tested in 3 sessions on the same day by 2 assessors. Signals were analyzed to derive a tracking index (motor control), stretch index (spasticity), flexor modulation index (FMI) (muscle activation), force angle index (FAI) (stiffness), range of movement, and isometric force. RESULTS AND CONCLUSIONS: The means of all tests differed between impaired and unimpaired participants except for range of movement into flexion, the FAI, and the FMI. Repeatability coefficients for each test are presented as benchmark values for use in future trials in which the wrist rig tests may be used to detect change. Test-retest reliability was excellent in the impaired group (ICC = 0.88-0.98) and poor to excellent in the unimpaired group (ICC = 0.06-0.89). The Bland-Altman ranges showed no bias between assessors, and that the interassessor variability was similar to that between repeats by the same assessor for most tests.

Poststroke upper-limb rehabilitation using 5 to 7 inserted microstimulators: implant procedure, safety, and efficacy for restoration of function.

OBJECTIVE: To investigate the feasibility of implanting microstimulators to deliver programmed nerve stimulation for sequenced muscle activation to recover arm-hand functions. DESIGN: By using a minimally invasive procedure and local anesthesia, 5 to 7 microstimulators can be safely and comfortably implanted adjacent to targeted radial nerve branches in the arm and forearm of 7 subjects with poststroke paresis. The microstimulators' position should remain stable with no tissue infection and can be programmed to produce effective personalized functional muscle activity with no discomfort for a preliminary 12-week study. Clinical testing, before and after the study, is reported in the accompanying study. SETTING: Microstimulator implantations in a sterile operating room. PARTICIPANTS: Seven adults, with poststroke hemiparesis of 12 months or more. INTERVENTION: Under local anesthesia, a stimulating probe was inserted to identify radial nerve branches. Microstimulators were inserted by using an introducer and were retrievable for 6 days by attached suture. Each device was powered via a radiofrequency link from 2 external cuff coils connected to a control unit. MAIN OUTCOME MEASURES: To achieve low threshold values at the target sites with minimal implant discomfort. Microstimulators and external equipment were monitored over 12 weeks of exercise. RESULTS: Seven subjects were implanted with 41 microstimulators, 5 to 7 per subject, taking 3.5 to 6 hours. Implantation pain levels were 20% more than anticipated. No infections or microstimulator failures occurred. Mean nerve thresholds ranged between 4.0 to 7.7 microcoulomb/cm(2)/phase over 90 days, indicating that cathodes were within 2 to 4 mm of target sites. In 1 subject, 2 additional microstimulators were inserted. CONCLUSIONS: Microstimulators were safely implanted with no infection or failure. The system was reliable and programmed effectively to perform exercises at home for functional restoration.