Posts Tagged Wrist
[Abstract] Requirements for a home-based rehabilitation device for hand and wrist therapy after stroke
Recovering hand function to perform activities of
daily living (ADL), is a signiﬁcant step for stroke survivors
experiencing paresis in their upper limb. A home-based, robot
mediated training approach for the hand allows the patient to
continue their training independently after discharge to maximise
recovery at the patient’s pace. Developing such a hand/wrist
training device that is comfortable to wear and easy to use is the
objective of this work. Using a user-centred design approach, the
ﬁrst iteration of the design is based on the requirements derived
from the users and therapists, leading to a ﬁrst prototype. The
prototype is then compared and evaluated against the required
features. This paper highlights the methodology used in the
process of validating the design against our initial brief.
[Abstract] Combined action observation- and motor imagery-based brain computer interface (BCI) for stroke rehabilitation: a case report – Full text PDF
Upper extremity impairment is a problem usually found in poststroke patients, and it is seldom completely improved even following conventional physical therapy. Motor imagery (MI) and action observation (AO) therapy are mental practices that may regain motor function in poststroke patients, especially when integrating them with brain-computer interface (BCI) technology. However, previous studies have always investigated the effects of an MI- or AO-based BCI for stroke rehabilitation separately. Therefore, in this study, we aimed to propose the effectiveness of a combined AO and MI (AOMI)-based BCI with functional electrical stimulation (FES) feedback to improve upper limb functions and alter brain activity patterns in chronic stroke patients. Case presentation: A 53-year-old male who was 12 years post stroke was left hemiparesis and unable to produce any wrist and finger extension. Intervention: The participant was given an AOMI-based BCI with FES feedback 3 sessions per week for 4 consecutive weeks, and he did not receive any conventional physical therapy during the intervention. The Fugl-Meyer Assessment of Upper Extremity (FMA-UE) and active range of motion (AROM) of wrist extension were used as clinical assessments, and the laterality coefficient (LC) value was applied to explore the altered brain activity patterns affected by the intervention. Outcomes: The FMA-UE score improved from 34 to 46 points, and the AROM of wrist extension was increased from 0 degrees to 20 degrees. LC values in the alpha band tended to be positive whereas LC values in the beta band seemed to be slightly negative after the intervention.
An AOMI-based BCI with FES feedback training may be a promising strategy that could improve motor function in poststroke patients; however, its efficacy should be studied in a larger population and compared to that of other therapeutic methods.
[Abstract + References] Performance Evaluation of the BioBall Device for Wrist Rehabilitation in Adults and Young Adults – Conference paper
The BioBall device, developed for wrist function rehabilitation, allows the execution of movements with a greater level of control. A component was added to make it possible to read the range of motion of the patient’s wrist. Thus, this project came up intending to evaluate the performance and suitability of the BioBall device for wrist function rehabilitation. To this end, a technical evaluation was performed in order to verify the consistency and accuracy of BioBall. Technical tests consisted of amplitude readings taken by the device, either in automatic or manual mode, “Passive Exercise” and “Physical Exercise” respectively. From the results obtained in this analysis it was concluded that the BioBall device, besides functioning correctly, can collect the angular data with consistency and it is suitable to follow the evolution of a patient’s rehabilitation. In order to evaluate whether the BioBall device performs reproducible and repeatable range of motion measurements, a test-retest was performed on healthy subjects (with the space of one week). The maximum amplitude of each wrist movement of the participants was measured. The results of the statistical analysis showed that, although there is some variation in the amplitudes obtained between the test and the retest, the device has good reliability in measuring the range of motion of the wrist.
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[ARTICLE] Effects of a robot‐aided somatosensory training on proprioception and motor function in stroke survivors – Full Text
Proprioceptive deficits after stroke are associated with poor upper limb function, slower motor recovery, and decreased self-care ability. Improving proprioception should enhance motor control in stroke survivors, but current evidence is inconclusive. Thus, this study examined whether a robot-aided somatosensory-based training requiring increasingly accurate active wrist movements improves proprioceptive acuity as well as motor performance in chronic stroke.
Twelve adults with chronic stroke completed a 2-day training (age range: 42–74 years; median time-after-stroke: 12 months; median Fugl–Meyer UE: 65). Retention was assessed at Day 5. Grasping the handle of a wrist-robotic exoskeleton, participants trained to roll a virtual ball to a target through continuous wrist adduction/abduction movements. During training vision was occluded, but participants received real-time, vibro-tactile feedback on their forearm about ball position and speed. Primary outcome was the just-noticeable-difference (JND) wrist position sense threshold as a measure of proprioceptive acuity. Secondary outcomes were spatial error in an untrained wrist tracing task and somatosensory-evoked potentials (SEP) as a neural correlate of proprioceptive function. Ten neurologically-intact adults were recruited to serve as non-stroke controls for matched age, gender and hand dominance (age range: 44 to 79 years; 6 women, 4 men).
Participants significantly reduced JND thresholds at posttest and retention (Stroke group: pretest: mean: 1.77° [SD: 0.54°] to posttest mean: 1.38° [0.34°]; Control group: 1.50° [0.46°] to posttest mean: 1.45° [SD: 0.54°]; F[2,37] = 4.54, p = 0.017, ηp2 = 0.20) in both groups. A higher pretest JND threshold was associated with a higher threshold reduction at posttest and retention (r = − 0.86, − 0.90, p ≤ 0.001) among the stroke participants. Error in the untrained tracing task was reduced by 22 % at posttest, yielding an effect size of w = 0.13. Stroke participants exhibited significantly reduced P27-N30 peak-to-peak SEP amplitude at pretest (U = 11, p = 0.03) compared to the non-stroke group. SEP measures did not change systematically with training.
This study provides proof-of-concept that non-visual, proprioceptive training can induce fast, measurable improvements in proprioceptive function in chronic stroke survivors. There is encouraging but inconclusive evidence that such somatosensory learning transfers to untrained motor tasks.
Trial registration Clinicaltrials.gov; Registration ID: NCT02565407; Date of registration: 01/10/2015; URL: https://clinicaltrials.gov/ct2/show/NCT02565407.
Nearly two-thirds of stroke survivors exhibit forms of somatosensory or proprioceptive dysfunction [1, 2]. Proprioceptive deficits are related to longer length-of-stay in hospitals , poor quality of movement, poorer activities of daily (ADL) function and reduced participation in physical activity [4,5,6]. Proprioceptive deficits predict treatment responses to robot-assisted motor retraining with augmented proprioceptive feedback  These may be explained by the crucial role of proprioception in motor control and learning [8, 9]. Proprioceptive training is a form of somatosensory intervention that aims to enhance proprioceptive function. Several forms of somatosensory intervention such as passive, repetitive cutaneous stimulation [10, 11], passive limb movement training , repeated somatosensory discrimination practice and active sensorimotor training with augmented somatosensory feedback [7, 13, 14, 15] have been proposed to aid recovery of proprioceptive function and motor function after stroke. Proprioceptive improvements observed after proprioceptive training interventions correlated with improvement of untrained motor performance in healthy young adults [16, 17]. This further supports the rationale to implement proprioceptive-motor training for people with stroke. Among all types of proprioceptive intervention, active sensorimotor training with augmented somatosensory feedback [7, 13,14,15] seem to produce consistent results across studies [1, 18]. These interventions often employ somatosensory signals either to replace visual feedback on motor performance or to augment existing visual and somatosensory feedback for online motor control. One well studied mode of somatosensory feedback is vibro-tactile feedback (VTF) applied to the skin surface. Incorporating VTF with movement training has been shown to improve the learning of simple motor tasks in healthy adults and clinical populations [19,20,21]. There is evidence that it can effectively enhance proprioceptive function .
Somatosensory evoked potentials (SEPs) recorded via electroencephalography (EEG) are an objective neurophysiological marker of somatosensory processing with established procedures and normative values that has been used among clinical populations. Adults after stroke typically present with a lower peak amplitude or longer peak latency of SEPs (e.g. [23, 24]). Moreover, the restoration of typical SEPs has been reported following somatosensory interventions [25, 26]. Thus, we here recorded SEP to verify changes in the neural processing of somatosensory signals in sensorimotor cortex as a function of the somatosensory-motor intervention employed in this project […]
Posted by Debbie Overman
The U.S. Food and Drug Administration has authorized the marketing of the IpsiHand, a new device indicated for use in patients 18 and older undergoing stroke rehabilitation to facilitate muscle re-education and for maintaining or increasing range of motion.
The IpsiHand Upper Extremity Rehabilitation System (IpsiHand System), from Neurolutions Inc, is a Brain-Computer-Interface (BCI) device that assists in rehabilitation for stroke patients with upper extremity—or hand, wrist and arm—disability.
“Thousands of stroke survivors require rehabilitation each year. Today’s authorization offers certain chronic stroke patients undergoing stroke rehabilitation an additional treatment option to help them move their hands and arms again and fills an unmet need for patients who may not have access to home-based stroke rehabilitation technologies.”
— Christopher M. Loftus, MD, acting director of the Office of Neurological and Physical Medicine Devices in the FDA’s Center for Devices and Radiological Health
Designed for Post-Stroke Rehab
Although stroke is a brain disease, it can affect the entire body and sometimes causes long-term disability such as complete paralysis of one side of the body (hemiplegia) or one-sided weakness (hemiparesis) of the body. Stroke survivors may have problems with the simplest of daily activities, including speaking, walking, dressing, eating and using the bathroom.
Post-stroke rehabilitation helps individuals overcome disabilities that result from stroke damage. The IpsiHand System uses non-invasive electroencephalography (EEG) electrodes instead of an implanted electrode or other invasive feature to record brain activity. The EEG data is then wirelessly conveyed to a tablet for analysis of the intended muscle movement (intended motor function) and a signal is sent to a wireless electronic hand brace, which in turn moves the patient’s hand. The device aims to help stroke patients improve grasping. The device is prescription-only and may be used as part of rehabilitation therapy.
The FDA assessed the safety and effectiveness of the IpsiHand System device through clinical data submitted by the company, including an unblinded study of 40 patients over a 12-week trial. All participants demonstrated motor function improvement with the device over the trial. Adverse events reported included minor fatigue and discomfort and temporary skin redness.
The IpsiHand System device should not be used by patients with severe spasticity or rigid contractures in the wrist and/or fingers that would prevent the electronic hand brace from being properly fit or positioned for use or those with skull defects due to craniotomy or craniectomy.
The IpsiHand System device was granted Breakthrough Device designation, which is a process designed to expedite the development and review of devices that may provide for more effective treatment or diagnosis of life-threatening or irreversibly debilitating diseases or conditions.
The FDA reviewed the IpsiHand System device through the De Novo premarket review pathway, a regulatory pathway for low- to moderate-risk devices of a new type. Along with this authorization, the FDA is establishing special controls for devices of this type, including requirements related to labeling and performance testing. When met, the special controls, along with general controls, provide reasonable assurance of safety and effectiveness for devices of this type.
This action creates a new regulatory classification, which means that subsequent devices of the same type with the same intended use may go through the FDA’s 510(k) premarket process, whereby devices can obtain clearance by demonstrating substantial equivalence to a predicate device.
The FDA granted marketing authorization of the Neurolutions IpsiHand Upper Extremity Rehabilitation System to Neurolutions Inc.
[Source(s): US Food and Drug Administration, PR Newswire]
Background: In this study, an active orthosis has been designed to rehabilitate patients with weak wrist flexor and extensor muscles.
Methods: First, the mechanical design of the actuating mechanism with a linear servo motor to provide the desired wrist rotation, is performed in SolidWorks software. Also, to determine the force created by the actuator during flexion and extension of the wrist, the movement of the mechanism is simulated in Visual Nastran software. After molding the patient’s wrist, the main body of the orthosis is made by forming the thermoplastic sheets on the mold, and the components of the mechanical part of the mechanism are installed on it. Then, the hardware part of the electronic circuits to drive the motor and to communicate between the control modules and the actuator is designed. For the programming of microcontrollers and synchronizing of deriver to the joystick, Bascom AVR software is used. The simulation of electrical circuit is performed in Proteus software and the printed board circuit is made in Altium Designer software.
Results: The results of applying this orthosis on the wrist of a healthy subject indicate its proper performance in creating an acceptable angle range for the wrist extension and flexion.
Conclusion: The use of the designed active wrist orthosis can improve the rehabilitation process of the patients with weakness in their wrist muscles.
[ARTICLE] Repetitive Peripheral Magnetic Stimulation of Wrist Extensors Enhances Cortical Excitability and Motor Performance in Healthy Individuals – Full Text
Repetitive peripheral magnetic stimulation (rPMS) may improve motor function following central nervous system lesions, but the optimal parameters of rPMS to induce neural plasticity and mechanisms underlying its action remain unclear. We examined the effects of rPMS over wrist extensor muscles on neural plasticity and motor performance in 26 healthy volunteers. In separate experiments, the effects of rPMS on motor evoked potentials (MEPs), short-interval intracortical inhibition (SICI), intracortical facilitation (ICF), direct motor response (M-wave), Hoffmann-reflex, and ballistic wrist extension movements were assessed before and after rPMS. First, to examine the effects of stimulus frequency, rPMS was applied at 50, 25, and 10 Hz by setting a fixed total number of stimuli. A significant increase in MEPs of wrist extensors was observed following 50 and 25 Hz rPMS, but not 10 Hz rPMS. Next, we examined the time required to induce plasticity by increasing the number of stimuli, and found that at least 15 min of 50 and 25 Hz rPMS was required. Based on these parameters, lasting effects were evaluated following 15 min of 50 or 25 Hz rPMS. A significant increase in MEP was observed up to 60 min following 50 and 25 Hz rPMS; similarly, an attenuation of SICI and enhancement of ICF were also observed. The maximal M-wave and Hoffmann-reflex did not change, suggesting that the increase in MEP was due to plastic changes at the motor cortex. This was accompanied by increasing force and electromyograms during wrist ballistic extension movements following 50 and 25 Hz rPMS. These findings suggest that 15 min of rPMS with 25 Hz or more induces an increase in cortical excitability of the relevant area rather than altering the excitability of spinal circuits, and has the potential to improve motor output.
Peripheral nerve electrical stimulation is known to augment synaptic plasticity in motor cortex and spinal circuits in healthy individuals and in patients following stroke (Ridding et al., 2000; Kaelin-Lang et al., 2002; Khaslavskaia et al., 2002; McKay et al., 2002; Knash et al., 2003; Everaert et al., 2010; Mang et al., 2010; Chipchase et al., 2011a, b; Schabrun et al., 2012; Yamaguchi et al., 2012, 2013; Gallasch et al., 2015; Sasaki et al., 2017; Takahashi et al., 2018). Since synaptic plasticity is observed following rehabilitation and motor skill training, these changes may play an important role in the recovery (Nudo et al., 1996) and improvement of motor performance (Lotze et al., 2003; Perez et al., 2004; Tatemoto et al., 2019).
Repetitive peripheral magnetic stimulation (rPMS), as well as peripheral nerve electrical stimulation, can induce muscle contraction. However, magnetic stimulation is less painful than electrical stimulation, since the eddy current induced by magnetic stimulation directly stimulates deep tissues without penetrating the skin (Polson et al., 1982). Therefore, rPMS is less likely to induce discomfort, which is useful for patients in clinical settings. Previous studies have shown that rPMS improves motor dysfunction following central nervous system (CNS) lesions (Struppler et al., 2003; Flamand et al., 2012; Beaulieu and Schneider, 2013; Flamand and Schneider, 2014); however, stimulus parameters such as frequency and intervention time in these reports are not constant, and plastic changes in cortical excitability have not been directly investigated.
Gallasch et al. (2015) investigated the effects of two different frequencies of rPMS on cortical excitability, demonstrating that the cortical excitability of wrist flexor muscles increased following 25 Hz rPMS for 20 min, but not for 10 Hz rPMS. To align the intervention time, however, the number of stimuli was different for each frequency condition; therefore, it is unclear whether the cortical excitability changes induced by rPMS were frequency-dependent (Pitcher et al., 2003; Mang et al., 2010; Gallasch et al., 2015), dose-dependent (McKay et al., 2002; Andrews et al., 2013) or both. In addition, they reported that a facilitatory effect was observed following a series of rPMS for 20 min, but no study has examined the intervention timeframe of rPMS required to induce the changes in cortical excitability. If changes in cortical excitability are induced following rPMS, the effects may improve motor performance; however, these questions still remain unclear. This investigation has clinical implications for the application of rPMS in the rehabilitation of individuals with CNS lesions. The aim of this study was to investigate the effects of different rPMS parameters in wrist muscles on the excitability of cortical and spinal networks, and motor performance, in healthy individuals.[…]
In order to regain the activities of daily living (ADL) for patients suffering from different conditions such as stroke and spinal cord injury, they must be treated with rehabilitation process through programmed exercises. The human motor system can learn through motor learning. This study concerned with the rehabilitation of wrist and forearm joints to restore the ADL through designing and constructing a robotic exoskeleton. The exoskeleton was designed to rehabilitate the patients by providing a 3 degree of freedom (DOF) include flexion/ extension, adduction/abduction, and pronation/ supination movements. It is specified as being portable, comfortable, lightweight, and compatible with the human anatomical structure, in addition to providing a speed and range of motion (ROM) as that of a normal subject. It was designed with SolidWorks software program and constructed with a 3D printer technique using polylactic acid (PLA) plastic material. The overall exoskeleton was controlled with electromyography and angle information extracted using EMG myoware and gyroscope sensors respectively. it was applied for evaluation with 5 normal subjects and 12 subjects of stroke and spinal cord injury (SCI). The results were found that the exoskeleton has a strong effect on regaining muscle activity and increasing the ROMs of wrist and forearm joints. These results give proof of this exoskeleton to be used for performing physiotherapy exercises.
[ARTICLE] Mechanical Design of a Bioinspired Compliant Robotic Wrist Rehabilitation Equipment – Full Text
Early social reintegration of patients with disabilities of the wrist is possible with the help of dedicated rehabilitation equipment. Using such equipment reduces the duration of recovery and reduces significantly rehabilitation costs. Based on these considerations the paper puts forward a novel constructive solution of rehabilitation equipment that ensures the simultaneous passive mobilization of the radiocarpal, metacarpophalangeal, and interphalangeal joints. The novelty of this equipment consists in the bioinspired concept of the hand support based on the Fin-Ray effect and in driving it by means of a pneumatic muscle, an inherently compliant actuator. The paper places an emphasis on the compliant character of the rehabilitation equipment that is responsible for its adaptability to the concrete conditions of patient pain tolerability.
The hand, with its 27 bones of the palm skeleton and the fingers, qualifies as the most complicated osteoarticular segment of the human body. This most complex articulation includes the 8 carpal bones displayed in two transversal rows forming the wrist, the 5 metacarpal bones, followed by the 14 phalanxes of the fingers. Obviously a bone system of such complexity is more susceptible to trauma that would inhibit the functions of the hand. Gripping, discriminatory sensitivity, expressivity, and conducting professional tasks can be thus hindered or even cancelled.Any partial or total impairment of the hand is a professional and social emergency that calls for therapeutical methods able to accelerate the recovery of the affected joint. Adequate medical treatment of the effects of trauma sustained by joints of the hand is typically followed by immobilization in a gypsum cast. However, extended repose of the joints leads to muscle hypertrophy or even atrophy, to bone demineralization and dysfunctions of the circulatory apparatus. Consequently, in order to prevent the negative effects of immobilization passive kinesiotherapy or excitomotor therapy (the latter in cases of muscle atrophy by denervation) are used [1,2,3]. These techniques are part of the general approach to swift patient rehabilitation and thus favor a high functional recovery rate and early return to work life.Motion-based rehabilitation of the hand depends of the location of the trauma and the type of the already applied (surgical or nonsurgical) treatment. The rehabilitation protocols are aimed mainly at pain control and restoring the functionality of the affected area. Such protocols need to be adapted to patients’ motor state (muscle tone), sensitivity state (proprioception), and last but not least to their psycho–social and occupational state.The functional reeducation program needs to be initiated approximately 3 days after the trauma has been treated. In order to avoid excessive local straining, the use of customized orthoses is recommended, as well as light physical exercises that consist of compression/elevation active and passive mobilization of the fingers .Subsequently to this stage continuous passive motion (CPM) is applied. This entails the mechanical mobilization of the affected joint without straining the patient’s muscles. These motions are designed to impede the generation of fibrous tissue and to reduce joint rigidity. CPM is performed by means of specially conceived equipment that is capable of applying customized optimum rehabilitation motions to the joint.The passive mobilization of the hand joints by means of rehabilitation equipment requires controlling the various parameters of the motion, like the amplitude and speed of the motion and duration and frequency of the exercises. Not to be neglected is the magnitude of the applied forces such as to ensure pain-free rehabilitation exercising. CPM rehabilitation equipment need to allow the adjustment of the quantities mentioned above so that rehabilitation exercises can be adapted to the clinical state of the patient.At present the rehabilitation of the hand joints is performed with the help of equipment the majority of that is actuated electrically. Thus the 6000 Hand CPM OrthoAgility® is used for postfracture recovery, reconstructive surgery on bone, cartilage, tendons, and ligaments, and allows patients to achieve a full composite fist of 270° . Another often-deployed piece of equipment is the Kinetec—8091 Portable Hand CPM designed for rehabilitation after prosthetic replacement of the MCP (MetaCarpoPhalangeal), PIP (Proximal InterPhalangeal) and DIP (Distal InterPhalangeal) joints, and related to rheumatoid/neurological or afterburn stiffness .Designed for postoperative rehabilitation, the Kinetec Maestra™ CPM is yet another device that provides a rehabilitation solution for wrist pathology, allowing the achievement of a full composite fist de 255° . The WaveFlex Hand system developed by Remington Medical is a light construction deployable both in hospital and in patients’ homes. It supports the performing of rehabilitation exercises within the limits of hand joint biomechanics .Recovery of hand joints is also conducted by means of a system with 3 degree-of-freedom that can be attached on a MIT-MANUS robot. This piece of equipment limits motion to 60°/60° in flexion/extension, 30°/45° in abduction/adduction, and 70°/70° in pronation/supination .Besides CPM-based rehabilitation literature also discusses game therapy for poststroke recovery of upper limbs. Thus, motor-training software on tablets or smartphones offer a low-cost, widely-available solution to supplement arm physiotherapy after stroke. Studies involving 127 therapists revealed that the most commonly used device was Nintendo Wii. Gaming was reported to be enjoyable but therapists described barriers, which relate to time, space and cost [10,11,12].This category of game therapy includes also a smart mobile device for the assessment and training of hand functions called GripAble Device , which is connected to a tablet by means of a dedicated software application. Its deployment is not based on CPM, as the equipment is driven by the patients themselves, patients who have not suffered total mobility loss.Given the benefits of soft robotics several research teams have developed variants of wearable orthotic devices for the rehabilitation of the hand. Known are for example the Exo-Glove PM—a customizable modularized pneumatic assistive glove  or the Harvard Soft Robotic Glove for Neuromuscular Rehabilitation developed by researchers of the Wyss Institute at Harvard University . In both cases the soft actuators are mobilized by compressed air.During rehabilitation exercising motion can often exceed the limits of patient supportability with the consequence of onsetting pain. The system’s response time since the moment of pain onset needs to be as small as possible and thus is an essential characteristic of any rehabilitation equipment. While the electrically actuated systems described above do have such a self-adaptive behavior, this is made possible only be excessive sensorization and complicated control diagrams, all of this leading to cost-intensive rehabilitation equipment.Rethinking their construction makes it possible to reduce the cost of rehabilitation equipment. By eliminating many of the sensors, simplifying control diagrams and most importantly by using adjustable compliance actuators (ACAs) performant equipment can be developed at significantly lesser costs. An example of adjustable compliance actuator is the pneumatic muscle whose inherently compliant behavior is due to air compressibility. Characteristics of pneumatic muscles are safe interaction with human operators and their ability of storing and releasing energy into passive elastic elements .Conception of pneumatic muscle actuated rehabilitation equipment for hand joints is still in its incipient stage as to date merely few published patents are known and just a small number of prototypes or functional equipment. One such piece of equipment is the Hand Mentor Pro (manufactured by Motus Nova) actuated by a pneumatic muscle. The Hand Mentor is a stroke rehabilitation device that provides active assistance. It moves the patient like a skilled physical therapist, and is designed for recovering the gripping ability of the hand .Another example of rehabilitation equipment is the EXOWRIST, using four pneumatic muscle actuators to undertake the 2-degrees-of-freedom movements performed by the human wrist. It is characterized by adjustable performance to meet the needs of individualized configuration, assisted movement capabilities, high reliability in different treatment environments and conditions for safe human–robot interactions, low development and construction costs, and high portability for autonomous and independent use .Starting from the current state of available rehabilitation equipment for the joints of the hand and given the necessity of further developing such light, portable, affordable, and reliable systems benefitting from a compliant behavior this paper pots forward a novel constructive solution able to mobilize simultaneously both wrist and finger joints. The joints of the hand are set into motion by a pneumatic muscle, and the novel concept of the palm support is based on the Fin-Ray effect, bioinspired from the fins of fish.The structure of the paper includes a second section that describes the biomechanics of the hand joints and defines the limits of their motions. These are the input data used for the concept of the novel rehabilitation system. The third section of the paper presents the bioinspired elements that determine the concept of the equipment, as well as its functional principle and construction. The fourth section presents the experimental results and the last section is dedicated to the conclusions of the discussed study.
2. Biomechanics of the Hand Joints
The construction of this type of rehabilitation equipment is based on detailed knowledge of the anatomy of the hand and of the motions its joints are capable of conducting. Further necessary data are the limits to such motions and the generated forces and moments. Figure 1 details the main bones and joints of the hand skeleton :