Dynamic Hand Orthosis Research Articles

A Lightweight Dynamic Hand Orthosis With Sequential Joint Flexion Movement for Postoperative Rehabilitation of Flexor Tendon Repair Surgery.

During the postoperative hand rehabilitation period, it is recommended that the repaired flexor tendons be continuously glided with sufficient tendon excursion and carefully managed protection to prevent adhesion with adjacent tissues. Thus, finger joints should be passively mobilized through a wide range of motion (ROM) with physiotherapy. During passive mobilization, sequential flexion of the metacarpophalangeal (MCP) joint followed by the proximal interphalangeal (PIP) joint is recommended for maximizing tendon excursion. This paper presents a lightweight device for postoperative flexor tendon rehabilitation that uses a single motor to achieve sequential joint flexion movement. The device consists of an orthosis, a cable, and a single motor. The degree of spatial stiffness and cable path of the orthosis were designed to apply a flexion moment to the MCP joint prior to the PIP joint. The device was tested on both healthy individuals and a patient who had undergone flexor tendon repair surgery, and both flexion and extension movement could be achieved with a wide ROM and sequential joint flexion movement using a single motor.

Upper limb practice with a dynamic hand orthosis to improve arm and hand function in people after stroke: a feasibility study

BackgroundDynamic hand orthosis may help upper limb recovery by keeping the wrist and hand in an optimal position while executing a grasp. Our aim was to investigate the feasibility of combining a dynamic hand orthosis with task-oriented upper limb practice after stroke.MethodFifteen adult stroke survivors were recruited in a single-group, pre-post intervention study. They received 12 weeks of task-oriented upper limb training with a dynamic hand orthosis with 3 weeks supervised at a community rehabilitation unit followed by 9 weeks unsupervised at home. Feasibility was determined by recruitment (proportion of eligible/enrolled and enrolled/retained participants), intervention (adherence, acceptability, and safety) and measurement (time taken to collect outcomes and proportion of participants where all measures were collected). Clinical outcomes were measured at baseline (Week 0), end of Week 3 and Week 12.ResultsFifteen (46%) of eligible volunteers were enrolled in the study. Eight (53%) of those enrolled completed the 12-week intervention. Eighty eight percent were satisfied or very satisfied with the dynamic hand orthosis. Clinical measures were collected for all participants at baseline and in all those who completed the intervention but often took over one hour to complete. At 12 weeks, participants had improved by 7 points out of 57 (95% CI 2 to 13) on the ARAT and by 8 points out of 66 (95% CI 0 to 15) on the FMA-UE.ConclusionThe intervention appears to be feasible in terms of acceptability and safety, while recruitment and measurement need further consideration. The magnitude of the clinical outcomes suggests that the intervention has a potential to improve both upper limb activity and impairment, and this study provides useful information for the design of a pilot randomized trial.Trial registrationClinicalTrials.gov Identifier: NCT03396939.

Novel Procedure for Determining the Finger Force in Flexion Depending on the Finger Position

Abstract Introduction: The design and development of a novel dynamic hand orthosis that allows individual and progressive adaptation to the patient’s condition require knowledge about the maximum voluntary contraction forces of the fingers. The following work presents a test setup and procedure for determination of isometric finger contraction forces during flexion depending on various finger positions and finger tasks. Methods: The test setup places hand and fingers in certain positions (position 0: grasping of a plate; position 1-3: circular grasping of cylinders of three different diameters). The force measurement is carried out using pressure sensing: A capacitive force sensor is placed on each fingertip. To perform various finger tasks, the subjects are asked for isometric contraction of defined finger groups and single fingers against the boundary system. For proof of the concept, measurements are performed with six subjects and compared with reference values from the literature. Results: The separated finger force of each finger can be captured during the finger tasks in varying positions. Furthermore, the total finger force of all active fingers can be determined. It is shown that the total finger force during contraction of all fingers (IMRLtask; 78.4N ± 25.8N, d2) is higher than during contraction of the index finger (25.8N ± 3.4N, d2). Furthermore, the single finger force of the index finger is higher than the index finger activity in IMRL-task. The results also show a tendency for the finger contraction force to increase with increasing flexion. Further investigations may require improvements to the method. In this proof of concept, this potential is revealed and discussed. However, the functionality of the test setup and procedure can be demonstrated.

A study of dynamic hand orthosis combined with unilateral task-oriented training in subacute stroke: A functional near-infrared spectroscopy case series.

BackgroundMotor dysfunction in the upper extremities after stroke prohibits people with stroke from being independent in daily living. The application of fNIRS to explore brain activity under rehabilitation intervention is a research focus on neurorehabilitation.ObjectiveThe purpose of this study was to explore, using a grip-release ring motor task, the activated changes of regions of interest and changes in motor function utilizing fNIRS technology and test scales on persons with stroke who received unilateral task-oriented therapy with a hand orthosis in the early subacute stroke period before and after intervention. The study aimed to find a sensitive motor task and region of interest first, then to evaluate the feasibility and mechanism of this rehabilitation method by utilizing fNIRS technology in the next randomized controlled trial.MethodsIn this case series, eight right-handed, right hemiplegia subacute stroke persons (6 males,2 females from age 47 to 72) were enrolled. They received 30 min of unilateral task-oriented therapy without orthosis and 30 min of unilateral task-oriented therapy with orthosis (5 days/week) for 4 weeks. Activated channel numbers and beta values based on oxygenated hemoglobin concentration change using a grip-release ring motor task were estimated with fNIRS. Clinical outcome measures, including grip strength evaluation, action research arm test, and Fugl-Meyer assessment of the arm, were evaluated at the same time.ResultsIndividual activation analysis showed that, after intervention, Subjects 1, 2, 6, 7, and 8 had the maximum mean beta value located in the left premotor cortex, while Subjects 4 and 5 had the maximum mean beta value located in the left sensorimotor cortex. The activation analysis of Subject 3 showed the maximum mean beta value located in the right premotor cortex. Deactivations of left sensorimotor cortex, left premotor cortex, and bilateral prefrontal cortex were observed after intervention which were different from other cases. Group activation analysis showed that bilateral cerebral hemispheres were activated in all eight participants, with right hemisphere and right supplementary motor cortex activated dominantly. After the intervention, the activation of bilateral hemispheres decreased but in different brain regions; there was a trend that the activation intensity of left sensorimotor cortex, right premotor cortex, and right prefrontal cortex decreased while activation intensity of left premotor cortex and left prefrontal cortex increased. Each participant demonstrated improvements in all the clinical test scales after intervention.ConclusionsLeft premotor cortex, left sensorimotor cortex, and right supplementary motor cortex may be the primary regions of interest. Grasp-release ring task was not appropriate to achieve our fNIRS research objective and a more sensitive motor task or more sensitive evaluating indicator should be used in further studies.

Upper Limb Training with a Dynamic Hand Orthosis in Early Subacute Stroke: A Pilot Randomized Trial.

To investigate the effect of the addition of a dynamic hand orthosis to unilateral task-oriented training in early subacute stroke. Pilot randomized trial with concealed allocation, measurer blinding, and intention-to-treat analysis. Rehabilitation hospital. Thirty subacute stroke patients with moderate-to-severe upper limb disability. All participants received 4 weeks (60 min per day, 5 days a week) of unilateral task-oriented training. The experimental group (n = 15) wore a dynamic hand orthosis during half of the training time (i.e. 30 min per day). Primary outcome was the upper limb activity measured using the Action Research Arm Test (ARAT) measured at baseline and 4 weeks. Secondary outcomes were the Nine-hole Peg Test, Fugl-Meyer Assessment for upper extremity, grip strength, modified Ashworth Scale, Barthel Index and EuroQol-5D. No difference between groups was found for the primary outcome ARAT (mean difference 4/57, 95% confidence interval (95% CI) -5 to 13) nor for any secondary outcome. No additional benefit was found of wearing a dynamic hand orthosis during unilateral taskoriented training in the early subacute period.

Conceptualization of Hand-TaPS to measure the subjective experience of dynamic hand orthoses in promoting functional recovery at home after stroke.

Dynamic exoskeleton orthoses provide assistance needed to complete movements that would otherwise be impossible after stroke. Beyond the demonstration of their effectiveness, the subjective experience of dynamic orthoses also needs to be considered. To support functional recovery after stroke through the development of Hand-TaPS (Task Practice after Stroke), an instrument to evaluate dynamic hand orthoses in home therapy. Dynamic hand orthosis subject matter experts (N = 14), professionals and consumers, considered the items of PYTHEIA, a valid and reliable instrument merging well-tested, assistive technology (AT) assessment items with those tuned to the greater complexity of emerging technologies. Experts reflected on how each item aligned with their personal experience of dynamic orthosis use. Interpretative Phenomenological Analysis guided identification of themes. Four themes (5/20 items) appraised highly relevant for Hand-TaPS. The remaining eight themes (15/20 items) were deemed in need of modification. Dynamic hand orthoses constitute a special case of AT; the assistance they provide targets therapy, not ADLs. Our work to develop Hand-TaPS provides a clear example of the theoretical difference between rehabilitative and assistive technology and underscores the importance of consideration of how a device is used in its assessment.

Development of 3D-printed myoelectric hand orthosis for patients with spinal cord injury

BackgroundSpinal cord injury (SCI) is a severe medical condition affecting the hand and locomotor function. New medical technologies, including various wearable devices, as well as rehabilitation treatments are being developed to enhance hand function in patients with SCI. As three-dimensional (3D) printing has the advantage of being able to produce low-cost personalized devices, there is a growing appeal to apply this technology to rehabilitation equipment in conjunction with scientific advances. In this study, we proposed a novel 3D-printed hand orthosis that is controlled by electromyography (EMG) signals. The orthosis was designed to aid the grasping function for patients with cervical SCI. We applied this hand exoskeleton system to individuals with tetraplegia due to SCI and validated its effectiveness.MethodsThe 3D architecture of the device was designed using computer-aided design software and printed with a polylactic acid filament. The dynamic hand orthosis enhanced the tenodesis grip to provide sufficient grasping function. The root mean square of the EMG signal was used as the input for controlling the device. Ten subjects with hand weakness due to chronic cervical SCI were enrolled in this study, and their hand function was assessed before and after wearing the orthosis. The Toronto Rehabilitation Institute Hand Function Test (TRI-HFT) was used as the primary outcome measure. Furthermore, improvements in functional independence in daily living and device usability were evaluated.ResultsThe newly developed orthosis improved hand function of subjects, as determined using the TRI-HFT (p < 0.05). Furthermore, participants obtained immediate functionality on eating after wearing the orthosis. Moreover, most participants were satisfied with the device as determined by the usability test. There were no side effects associated with the experiment.ConclusionsThe 3D-printed myoelectric hand orthosis was intuitive, easy to use, and showed positive effects in its ability to handle objects encountered in daily life. This study proved that combining simple EMG-based control strategies and 3D printing techniques was feasible and promising in rehabilitation engineering.Trial registrationClinical Research Information Service (CRiS), Republic of Korea. KCT0003995. Registered 2 May 2019 - Retrospectively registered.

Diseño y manufactura de ortesis dinámica para mano mediante el modelado por deposición fundida (MDF)

Currently a large number of hand injuries occur in the Mexican population, mainly caused by accidents at work and in sports activities. To help the population have access to a brachiopalmar rehabilitation, In this work it was proposed to develop a rehabilitative prototype “dynamic hand orthosis” to address the main pathologies that affect our society (fractures, dislocations, sprains, tendonitis and sx of the carpal tunnel). The design was analyzed in a finite element for its validation, having a safety factor of 2.6 and a maximum tension of 12.84 MPa below the ABS elastic limit, Manufacturing was done using a 3D printer with the ABS filament. This orthosis has an extensor finger attachment composed of hammocks, one for each finger. Due to its universal design, it can be used for both hands only by exchanging the extension of the thumb.

Simplifying models and estimating grasp performance for comparing dynamic hand orthosis concepts.

While designing a dynamic hand orthosis to assist during activities of daily living, the designer has to know whether a concept will have sufficient grasp performance to support these activities. This is often estimated by measuring the interaction force at the contact interface. However, this requires a prototyping step and limits the practicality of comparing several concepts in an early design stage. Alternatively, this study presents and compares basic static and dynamic models to numerically estimate grasp performance. This was applied on an exemplary concept for a hydraulically operated hand orthosis grasping a circular object. The models were validated with an experimental set-up that does not require sensors at the contact interface. Static and dynamic model results were almost identical, where the static model could be around 10 times faster and is generally more robust to a high contact stiffness. Both models were unable to make accurate quantitative predictions, which is believed to be due to differences in used contact stiffness. However, the models were able to make correct qualitative comparisons, making it a valid method to compare and choose concepts in an early design stage.

Pilot Study Combining Electrical Stimulation and a Dynamic Hand Orthosis for Functional Recovery in Chronic Stroke.

We investigated the effect of a combined neuromuscular electrical stimulation (ES) and dynamic hand orthosis (DHO) regimen with a group of people with chronic stroke to improve performance on specific daily tasks. Four people with chronic stroke participated in an ES-DHO regimen using the affected upper extremity 5×/wk for 6 wk. Outcome measures included grip strength, range of motion (ROM), and analysis of muscle activation-deactivation during release of grasp through electromyography. Ability to perform specific daily living tasks was assessed using the Assessment of Motor and Process Skills (AMPS). Results suggested that improvements in strength, ROM, and grasp deactivation are possible with the combined ES-DHO regimen. All participants' AMPS motor scores improved. An ES-DHO regimen may improve motor skills needed for functional task performance in people with chronic stroke. Results should be interpreted cautiously because of the pilot nature of the study and the small sample size.

Evaluation of a functional hand orthosis combined with electrical stimulation adjunct to arm-hand rehabilitation in subacute stroke patients with a severely to moderately affected hand function

Purpose: To investigate the usability and effectiveness of a functional hand orthosis, combined with electrical stimulation adjunct to therapy-as-usual, on functional use of the moderately/severely impaired hand in sub-acute stroke patients.Materials and Methods: Single case experiment (A-B-A′-design) involving eight sub-acute stroke patients. The functional hand orthosis and electrical stimulation were used for six weeks, four days/week, 45′/day. Outcome measures: Action_Research_Arm_Test, Intrinsic_Motivation_Inventory.Results: At group level, patients improved 19.2 points (median value) (interquartile range: [8.8, 29.5] points) on the Action_Research_Arm_Test (p = 0.001). After correcting for spontaneous recovery and/or therapy-as-usual effects Action_Research_Arm_Test scores still improved significantly (median: 17.2 points; interquartile range: [5.1, 29.2] points) (p = 0.002). At individual level, six patients had improved as to arm-hand skill performance at follow-up (p < = 0.010). In one patient, arm-hand skill performance improvement did not attain statistical significance. In another patient, no arm-hand skill performance improvement was observed. Average Intrinsic_Motivation_Inventory sub-scores were between 4.6 and 6.3 (maximum: 7), except for ‘perceived pressure/tension’ (3.3).Conclusion: Sub-acute stroke patients who display only little/modest improvement on their capacity to perform daily activities, seem to benefit from training with a dynamic arm orthosis in combination with electrical stimulation. Patients’ perceived intrinsic motivation and sense of self-regulation was high.Implications for rehabilitationArm-hand training featuring the dynamic hand orthosis in combination with electrical stimulation shows a shift from no dexterity to dexterity.As to the users’ experience regarding the dynamic hand orthosis, patients perceive a high-intrinsic motivation and sense of self-regulation.Combining the orthosis with electrical stimulation creates opportunities for a nonfunctional hand towards task-oriented training.

Exploratory design of a compliant mechanism for a dynamic hand orthosis: Lessons learned.

This study does not describe a success-story. Instead, it describes an exploratory process and the lessons learned while designing a compliant mechanism for a dynamic hand orthosis. Tools from engineering optimization and rapid prototyping techniques were used, with the goal to design a mechanism to compensate for hypertonic or contracted finger muscles. Results show that the mechanism did not reach its design constraints, mostly because it could not provide for the necessary stiffness and compliance at the same time. Hence, the presented approach is more suited for design problems with either lower forces or less displacement. It was concluded that physiological stiffness models are an important part when modeling hand orthoses. Moreover, further research on compliant mechanisms in dynamic hand orthoses should focus on the feasibility of implementing more complex three-dimensional shapes, i.e., compliant shell mechanisms.

Effects of a dynamic hand orthosis for functional use of the impaired upper limb in sub-acute stroke patients: A multiple single case experimental design study

OBJECTIVE: To investigate the usability and the effects of a dynamic spring-loaded orthosis, adjunct to therapy-as-usual (TAU), on functional use of the impaired hand in moderately/severely impaired sub-acute stroke patients. DESIGN: Single case experiment (A-B-A’-design). SUBJECTS: Eight sub-acute stroke patients. METHODS: The orthosis was used for six weeks, five days/week, 45’/day, and adjunct to TAU. Outcome measures: Action Research Arm Test (ARAT), ABILHAND, Intrinsic Motivation Inventory (IMI). RESULTS: At group level, patients improved on ARAT (p = 0.001) and ABILHAND (p = 0.005). After detrending for baseline trends (caused by e.g. spontaneous recovery and/or TAU), such improvement was only found for ARAT (p = 0.009). At individual level, three patients whose baseline ARAT changed little (0–3 points), had improved at follow-up, and four remained constant regarding detrended ARAT results. In four patients mean detrended ABILHAND results were higher during follow-up relative to baseline (p 0.036). Average IMI sub-scores were between 5.4 and 6.6 (of 7), except for ‘pressure/tension’ (2.1). CONCLUSION: Patients, who, in the early sub-acute phase after stroke, display only little/modest improvement on their capacity to perform activities or their perceived level of daily performance, seem to benefit most from training with a dynamic arm orthosis. Patients perceived a high intrinsic motivation and sense of self-regulation.

Kinematics variations after spring-assisted orthosis training in persons with stroke

Static wrist splinting after stroke was not effective in facilitating distal movement. However, the purpose of this study is to evaluate the efficacy of training using kinematic parameters after a SaeboFlex orthosis training on chronic stroke patients. Five stroke patients participated in 4 weeks of training using a SaeboFlex orthosis for 1 hour per day, five times per week. Fugl-Meyer Assessment, Box and Block Test, Action Research Arm Test, and Kinematics using a three-dimensional motion analysis system were used for evaluating of training effects. The upper extremity score of the Fugl-Meyer Assessment and the Box and Block Test score were increased significantly after the intervention. The jerkiness score of the shoulder and elbow joints at the sagittal plane decreased significantly during the reach-to-grasp task at acromion height, and the jerkiness scores of the wrist joint during the reach-to-grasp task decreased significantly at both elbow and acromion heights. The results of this study indicate that a SaeboFlex training is effective in recovering the movement of the hemiparetic upper extremity of patients after stroke. Using a spring-assisted dynamic hand orthosis is considered to be an effective treatment option for providing repetition, task-oriented training, and real-world activities for the hemiparetic upper extremity, which was impaired hand to perform functional training.

Effect of Intensive Training With a pring-Assisted Hand Orthosis on Movement Smoothness in Upper Extremity Following Stroke: A Pilot Clinical Trial

Background: A commercial splinting system is designed to permit quick training in opening and closing the affected hand in order to overcome the disadvantages of previous approaches. Objective: The purpose of this study was to assess the feasibility of intensive training using a spring-assisted hand orthosis on upper extremity in individuals with chronic hemiparetic stroke. Design: Five participants for the experimental group and 5 for the control group were recruited from a local rehabilitation hospital. Subjects in the experimental group participated in 4 weeks of training using a SaeboFlex orthosis for 1 hour per day, 5 times per week. Each subject in the control group wore the same orthosis for 1 hour per day without participating in upper extremity training. Outcome measures included the Fugl-Meyer Assessment, Box and Block Test, and Action Research Arm Test; kinematic parameters were collected using a 3-D motion analysis system. Results: The Fugl-Meyer assessment and the Box and Block Test score were increased significantly in the experimental group after the intervention. The resultant velocity of the wrist joint for the reach-to-grasp task decreased significantly, and the resultant velocity of the shoulder joint while performing a reach-to-grasp task at acromion height decreased significantly in the experimental group. Conclusion: A pilot clinical study of spring-assisted dynamic hand orthosis training is feasible in recovering the movement of the hemiparetic upper extremity.

Attempting to Improve Function and Quality of Life Using the FTM Protocol

The Functional Tone Management (FTM) arm training program uses repetitive task practice, stretching, and electrical stimulation as patients with moderate upper extremity hemiparesis wear a dynamic hand orthosis to retrain grasp and release of objects. The case study quantitatively evaluates the extent to which FTM training improved function and quality of life in a patient who met criteria for which the device was intended. The participant, a 44-year-old male in the chronic stage of stroke recovery with moderate right upper extremity motor impairment, was trained for 10 days over a 2-week period by a licensed clinician with extensive experience in FTM training methods. Measurements were taken over 3 baseline visits, then immediately preintervention, postintervention, and at a 3-month follow-up. The outcome measures, following the International Classification of Functioning, Disability, and Health (ICF) Model, included the: Fugl-Meyer assessment (FMA) (upper extremity portion), UE range of motion (ROM), Modified Ashworth scale, Wolf Motor Function Test (WMFT), and the Motor Activity Log (MAL). Health related quality of life was measured using the Stroke Impact Scale (SIS). The participant showed limited gains in upper extremity function immediately postintervention. Increases in AROM occurred in forearm supination and wrist flexion and extension, but no improvements were noted in finger ROM. A slight decrease in tone was found in forearm pronators (1 to 0) and wrist flexors (1+ to 1). WMFT values for the more affected upper extremity did not change immediately after training, but a 17% reduction in time occurred at follow-up, with improvements, most notably in the tasks of lifting a pencil and lifting a paper clip. No changes occurred in UE-FMA scores immediately following the intervention, however, a 17% improvement was measured at followup. A slight improvement in MAL scores was noted but not to a level of independent functional use of the impaired upper extremity. SIS scores improved in the domains of strength, communication, mobility, social participation, hand recovery, and overall physical component, while decreases were seen in the ADL/IADL, hand function, emotion, and cognitive domains. The case study indicates that for this patient with chronic, moderate upper extremity impairment following stroke, a 2-week FTM training regimen resulted in modest changes occurring as a decrease in impairment, with functional improvement and improved quality of life. Further investigation of the innovative training program should be undertaken before the efficacy of its use can be ascertained amongst patients with limitations comparable to the participant.