A Dynamic Evaluation Mechanism of Human Upper Limb Muscle Forces

Finding enjoyable and effective long-term approaches to rehabilitation for improving the upper limb (UL) function of people with multiple sclerosis (MS) is challenging. Virtual reality (VR) with its engagement, interaction, and real time feedback could be a solution, with immersive VR systems having preliminary evidence in stroke to be more effective in improving UL outcomes in comparison to non-immersive VR. However, immersive VR research is limited within the realm of MS rehabilitation. Therefore, the main aim of the PhD was to explore immersive VR as an approach for UL rehabilitation for people with MS (pwMS). This was achieved in four stages: 1) a systematic review of the current evidence for VR in UL rehabilitation in MS; 2) predevelopment focus groups to determine requirements for the development of bespoke immersive VR games; 3) software development of bespoke VR games to potentially improve UL function for pwMS; and 4) a feasibility study of the games and immersive VR for pwMS’ UL rehabilitation. The systematic review initially yielded ten articles with varying study design, VR intervention and UL outcome measures used. There were some statistically significant improvements after VR interventions in outcomes such as in nine-hole peg test (NHPT), hand grip strength and active range of motion. There were however conflicting results regarding if VR was more effective than conventional approaches. Whilst the review demonstrated there were positive results for VR improving UL function, most of the studies had small sample sizes and were inadequately powered, and the level of immersion on effectiveness in MS remains unknown. The predevelopment focus groups recruited ten pwMS and eight specialist clinicians to explore their views on immersive VR as an approach to UL rehabilitation and determine requirements to develop VR games for this purpose. PwMS commonly reported that their UL problems interfered with activities of daily living and resulted in the loss of meaningful hobbies such as writing. Many pwMS neglected UL exercise and found strategies for adapting to their UL impairments. Similarly, clinicians stated UL rehabilitation was neglected within their service and that it was challenging to find interesting treatment strategies. VR was suggested by both participant groups as a potential solution, as it was convenient for pwMS to access and could provide a more engaging and disguised approach to exercise. Although, there were shared concerns about cybersickness and disengagement while using VR approaches. Finally, both groups agreed games should be meaningful and adaptable for users but suggested different VR activities, with clinicians suggesting games directly reflecting activities of daily living and pwMS suggesting more abstract activities. Recommendations were made for the development of VR rehabilitation games which could be personalised and customisable for the varying abilities of pwMS. Using theme-based content analysis and requirement analysis, requirements for the software development of immersive VR games were created and developed using Unity game engine. Three games, “Piano”; “Catch-a-falling-star” and “VR Whack-a-mole” which targeted dexterity and strength for pwMS were developed, with different difficulty levels implemented to adapt to varying ability of pwMS. The final stage of this PhD was a randomised, controlled feasibility study to investigate an intervention of immersive VR involving the three co-produced games for pwMS’ UL rehabilitation. Participants were randomised to either an intervention group consisting of 30 minutes of VR co-produced games, twice/week, for eight weeks, or to a control group of usual care. Participants were recruited from the NHS and third sector organisations. Nineteen pwMS were recruited (intervention n=11, control n=8), with a recruitment rate of 3.2 participants/month. Only minor adverse events were reported (n=9), such as fatigue and UL pain. Adherence was good with 87% (±12%) session completed, and two dropouts were reported in the control group. There were positive trends for improving NHPT and hand grip strength, but there was an observed ceiling effect in the Action Research Arm Test. Participants reported high levels of satisfaction and good usability of the co-produced VR games, as measured by the USE questionnaire. Thematic analysis revealed participants enjoyed the distraction and atmospheres that immersive VR provided, and believed the games were fit for purpose with the majority of participants reporting improvements in their UL function. Participants suggested more variety and progression of exercises for future development. Overall, these studies show that immersive VR has the potential to be beneficial for UL rehabilitation and is feasible and safe for pwMS. Therefore, future work should refine VR games for long-term application and explore the clinical and cost effectiveness of this approach.

The global incidence of spinal cord injury (SCI) is between 10 and 80 new cases per million people each year. This equates to between 250,000 and 500,000 injuries worldwide per year. In the United Kingdom, approximately 4400 people per year sustain an SCI. People with tetraplegia report upper limb function as their highest priority for improvement after SCI. Using immersive virtual reality (VR) headsets, physical rehabilitation exercises can be completed in engaging digital environments. Immersive VR therefore has the potential to increase the amount of therapy undertaken, leading to improvements in arm and hand function. There is little evidence supporting immersive VR as exercise in SCI, especially while patients with SCI are undergoing acute rehabilitation. In SCI research, co-design of new interventions is not a widely adopted approach, yet people with tetraplegia want to contribute with their expert knowledge on their experiences of SCI. This study aims to explore the lived experiences of people with tetraplegia and specialist SCI therapists related to acute upper limb rehabilitation and identify design considerations for VR-based interventions targeting the upper limb. We conducted 7 online focus groups using Microsoft Teams: 4 with people with tetraplegia (n=15; age range, 36-65 years) and 3 with occupational therapists and physiotherapists specializing in SCI rehabilitation (n=11). Participants were asked to discuss their experiences and expertise about acute SCI upper limb rehabilitation and their opinions and ideas on the use of VR for upper limb rehabilitation. The transcripts were analyzed using content analysis, enabling the proposition of design characteristics of a VR-based intervention for upper limb exercise. The study identified 5 major themes describing the clinical features, treatment, and recovery of people with SCI during the acute stage of SCI, their motivations for participating in therapy, and suggestions for the design of a VR intervention in treating the upper limbs following SCI. The themes identified in this study allow the elicitation of software requirements for a bespoke immersive VR platform for upper limb rehabilitation following SCI. They can also contribute to a better understanding of the advantages of using VR as an adjunct to upper limb rehabilitation. Additionally, participants used their expertise to suggest factors that would enable the development of a usable and effective intervention, as well as identifying potential pitfalls and software features to avoid during intervention development. These findings can be used to design accessible VR applications for use by people with tetraplegia and their therapists.

Stroke patients in rehabilitation period often encounter problems such as high training cost and weak self supervision. We proposed a rehabilitation evaluation method of upper limb function based on wearable inertial sensor data acquisition auxiliary equipmen, which aims to realize the self-monitoring and evaluation of rehabilitation of patients in the middle and late stage of upper limb function rehabilitation. We have used three inertial sensing units MPU6050 to make wearable upper limb rehabilitation training auxiliary equipment, which can collect the motion data of stroke patients in rehabilitation period during daily rehabilitation training. Combined with lindmark upper limb rehabilitation scale, we collected eight hand gesture data for upper limb rehabilitation exercise evaluation. For the original data, quaternion data and Euler angle data, we established upper limb rehabilitation training action evaluation models based on libsvm, multi-layer LSTM and cnn-lstm neural network respectively to evaluate the rehabilitation status of patients. The results show that CNN LSTM model has the best performance, with the recognition accuracy of 99.67%, followed by multi-layer LSTM, and the model recognition accuracy of 97.00%. The work of this paper will provide a reference for patients in the middle and later rehabilitation stage of upper limb after stroke to realize their own supervised rehabilitation training and recovery state evaluation.KeywordsInertial sensorsWearable devicesUpper limb rehabilitation training and assessment

Background: Stroke contributes to disability and mortality worldwide, with upper limb impairments significantly reducing arm and hand function, leading to profound disability. Traditional rehabilitation often lacks effectiveness in fully restoring upper limb function post-stroke. Powered exoskeletal systems offer adaptive support customized to stroke survivors’ needs. This review explores their development, advancements, and clinical applications, emphasizing their potential to improve motor recovery and independence in stroke survivors. Aim: To review evidence of the Soft Robotics for upper limb function in individuals with stroke. Relevance: This study explores the evidence of Soft Robotics as an intervention in Upper limb rehabilitation in Stroke, providing valuable insights for advancing evidence – based practices in physiotherapy. Methods: Data Identification- Search was done on the Pubmed databases, and search engines google scholar, research gate, Sci-Hub, Directory of Open Access Journals. Study Selection-Articles were identified. 10 studies published between 2018 to 2024 were reviewed. Results: A total of 10 studies of Soft Robotics f as an intervention in Upper limb rehabilitation in Stroke, most studies reflect significant improvement in hand function, more accurate & more portable, reducing cost of rehabilitation, friendly use- user interface thus enhance independence among stroke survivors. Conclusion: Development of Soft Robotics as an intervention in Upper limb rehabilitation in Stroke, shows promising results in field of rehabilitation. Future research should focus on exploring more data, improved customization and clinical trials, affordability, and home-based designs to broaden accessibility& effectiveness in rehabilitation.

Our previous studies showed that venous occlusion or passive stretch of the lower limb, assuming a mechanical stimulus, attenuates the vasoconstriction in the non-exercised forearm during postexercise muscle ischaemia (PEMI) of the upper limb. In this study, we investigated whether a metabolic stimulus to the lower limb induces a similar response. Eight subjects performed a 2 min static handgrip exercise at 30% maximal voluntary contraction (MVC) followed by 3 min PEMI of the upper limb, concomitant with or without 2 min static ankle dorsiflexion at 30% MVC followed by 2 min PEMI of the lower limb. During PEMI of the upper limb alone, forearm blood flow (FBF) and forearm vascular conductance (FVC) in the non-exercised arm decreased significantly, whereas during combined PEMI of the upper and lower limbs, the decreases in FBF and FVC produced by PEMI of the upper limb was attenuated. Forearm blood flow and FVC were significantly greater during combined PEMI of the upper and lower limbs than during PEMI of the upper limb alone. When PEMI of the lower limb was released after combined PEMI of the upper and lower limbs (only PEMI of the upper limb was maintained continuously), the attenuated decreases in FBF and FVC observed during combined PEMI of the upper and lower limbs was not observed. Thus, forearm vascular responses differ when muscle metaboreceptors are activated in the upper limb and when there is combined activation of muscle metaboreceptors in both the upper and lower limbs.

Determination of muscle forces in individual muscles is often essential to assess optimal performance of human motion. Inverse dynamic methods based on the kinematics of the given motion and on the use of optimisation approach are the most widely used for muscle force estimation. The aim of this study was to estimate how the choice of muscle model influences predicted muscle forces. Huxley's (1957, Prog Biophys Biop Chem. 7: 255–318) and Hill's (1938, Proc R Soc B. 126: 136–195) muscle models were used for determination of muscle forces of two antagonistic muscles of the lower extremity during cycling. Huxley's model is a complex model that couples biochemical and physical processes with the microstructure of the muscle whereas the Hill's model is a phenomenological model. Muscle forces predicted by both models are within the same range. Huxley's model predicts more realistic patterns of muscle activation but it is computationally more demanding. Therefore, if the overall muscle forces are to be assessed, it is reasonable to use a simpler implementation based on Hill's model.

IntroductionEmerging evidence suggests that robotic devices for upper limb rehabilitation after a stroke may improve upper limb function. For robotic upper limb rehabilitation in stroke to be successful, patients’ experiences...

The upper-limb rehabilitation robots can be developed as an efficient tool for motor function assessments. Circle-drawing has been used as a specific task for robot-based motor function measurement. The upper-limb movement-related kinematic and kinetic parameters measured by motion and force sensors embedded in the rehabilitation robots have been widely studied. However, the muscle synergies characterized by multiple surface electromyographic (sEMG) signals in upper limbs during human-robot interaction (HRI) with circle-drawing movements are rarely investigated. In this research, the robot-assisted and constrained circle-drawing movements for upper limb were used to increase the consistency of muscle synergy features. Both clockwise and counterclockwise circle-drawing tasks were implemented by all healthy subjects using right hands. The sEMG signals were recorded from six muscles in upper limb, and nonnegative matrix factorization (NMF) analysis was utilized to obtain muscle synergy information. Both synergy pattern and activation coefficient were calculated to represent the spatial and temporal features of muscle synergies, respectively. The results obtained from the experimental study confirmed that high structural similarity of muscle synergies was found among the subjects during HRI with circle-drawing movement by healthy subjects, which indicates healthy people may share a common underlying muscle control mechanism during constrained upper-limb circle-drawing movement. This study indicates the muscle synergy analysis during the HRI with constrained circle-drawing movement could be considered as a task for upper-limb motor function assessment.

Design of an Upper Limb Rehabilitation Robot Based on Medical Theory

The use of upper limb rehabilitation robots to assist the affected limbs for active rehabilitation training is an inevitable trend in the field of rehabilitation medicine. In particular, the active motion intention-based control of the upper limb rehabilitation robots to assist subjects in rehabilitation training is a hot research topic in human-computer interaction control. Therefore, improving the accuracy of active motion intention recognition is the premise of the human-machine interaction controller design. Furthermore, there are external disturbances (bounded/unbounded disturbances) during rehabilitation training, which seriously threaten the safety of subjects. Thereby, eliminating external disturbances (especially unbounded disturbances) is the difficulty and key to the human-machine interaction control of the upper limb rehabilitation robots. In response to these problems, based on the surface electromyogram signal of the human upper limb, this paper proposes a fuzzy neural network active motion intention recognition method to explore the internal connection between the surface electromyogram signal of the human upper limb and active motion intention, and improve the real-time and accuracy of recognition. Based on this, two types of human-machine interaction controllers, which can be called as zeroing neural network controller and noise-suppressing zeroing neural network controller are designed to establish a safe and comfortable training environment to avoid secondary damage to the affected limb. Numerical experiments verify the feasibility and effectiveness of the proposed theories and methods.

Combination of Exoskeletal Upper Limb Robot and Occupational Therapy Improve Activities of Daily Living Function in Acute Stroke Patients

Upper limb exoskeletons have drawn significant attention in neurorehabilitation because of the anthropomorphic mechanical structure analogous to human anatomy. Whereas, the training movements are typically unorganized because most exoskeletons ignore the natural movement characteristic of human upper limbs, particularly inter-joint postural synergy. This paper introduces a newly developed exoskeleton (Armule) for upper limb rehabilitation with a postural synergy design concept, which can reproduce activities of daily living (ADL) motion with the characteristics of human natural movements. The semitransparent active control strategy with the interactive force guidance and visual feedback ensured the active participation of users. Eight participants with hemiplegia due to a first-ever, unilateral stroke were recruited and included. They participated in exoskeleton therapy sessions for 4 weeks, with passive/active training under trajectories and postures with the characteristics of human natural movements. The primary outcome was the Fugl-Meyer Assessment for Upper Extremities (FMA-UE). The secondary outcomes were the Action Research Arm Test(ARAT), modified Barthel Index (mBI), and metric measured with the exoskeleton After the 4-weeks intervention, all subjects showed significant improvements in the following clinical measures: the FMA-UE (difference, 11.50 points, p = 0.002), the ARAT (difference, 7.75 points ), and the mBI (difference, 17.50 points, p = 0.003 ) score. Besides, all subjects showed significant improvements in kinematic and interaction force metrics measured with the exoskeleton. These preliminary results demonstrate that the Armule exoskeleton could improve individuals' motor control and ADL function after stroke, which might be associated with kinematic and interaction force optimization and postural synergy modification during functional tasks.

The purposes of the study were to establish isometric torque reference values for healthy 6- to 8-year-old children for 6 lower extremity muscles and determine the effects of gender, age, height, weight, and physical activity upon strength. A hand-held dynamometer was used to obtain force/torque values for 154 children. Age-referenced force/torque and cutoff values are provided for each muscle group. Torque increased with age and height for all muscles and with weight for all muscles except knee extensors. No gender differences were found. Children who participated in 3 or more hours per week in organized sports were stronger in 4 of 6 muscles; the number of hours spent in active play did not affect torque. This study provides hand-held dynamometer strength reference values to enable clinicians to determine if clients of the same age, height, and weight have muscle weakness.

Background/Aims For people living with acquired brain injury from stroke or trauma, clinical practice guidelines recommend high-intensity physical rehabilitation to optimise motor outcomes. There is an acknowledged evidence–practice gap between routine clinical practice and the amount, intensity and type of active upper limb rehabilitation recommended in research-informed guidelines. The aims of this study were to identify methods used to facilitate high doses of upper limb practice in published trials, understand stakeholder perspectives of the barriers and enablers to these methods in hospital settings, and to synthesise findings to form an evidence-based action plan for rehabilitation professionals, service providers and adults living with an acquired brain injury. Methods A rapid systematic literature review and a series of qualitative interviews with service users and rehabilitation clinicians explored the evidence on intensity and the experience of high intensity rehabilitation following brain injury and stroke. Triangulating this mixed method evidence, recommendations were generated on how to increase upper limb rehabilitation intensity during inpatient therapy. Results There was consensus in the literature that high-dose motor training improves a person's ability to move their hand and arm after brain injury and stroke. Trials mostly delivered therapy programmes as a replacement to usual care; however, it was unclear how high-intensity therapy was integrated into usual rehabilitation. Methods employed to increase the intensity of upper limb rehabilitation included strategies to optimise engagement (eg encourage independent practice and more practice); clinician-related processes (eg self-auditing, use of groups); environmental factors (eg equipment, dedicated space); and organisational influences (eg professional development, dedicated research positions and mentoring). Qualitative data showed that barriers and facilitators stem from service user factors (eg cognitive ability, advanced age, cultural mores) as well as clinician factors (eg quality of the therapeutic relationship, type and quality of therapist instructions). Organisational factors such as a strong research culture and a commitment to evidence-based practice positively influenced outcomes. Conclusions There is capacity to increase the intensity of upper limb rehabilitation by optimising organisational support and systems, as well as greater service user engagement in therapy processes. Implications for practice Rehabilitation clinicians have long understood that dose is a critical component of motor training. Findings may assist with structuring upper limb rehabilitation programs and addressing clinician factors to increase the intensity of therapy.

BackgroundIt is common for people with persistent spasticity due to a stroke to receive an injection of botulinum toxin-A in the upper limb, however post-injection intervention varies.AimTo determine the long-term effect of additional upper limb rehabilitation following botulinum toxin-A in chronic stroke.MethodAn analysis of long-term outcomes from national, multicenter, Phase III randomised trial with concealed allocation, blinded measurement and intention-to-treat analysis was carried out. Participants were 140 stroke survivors who were scheduled to receive botulinum toxin-A in any muscle(s) that cross the wrist because of moderate to severe spasticity after a stroke greater than 3 months ago, who had completed formal rehabilitation and had no significant cognitive impairment. Experimental group received botulinum toxin-A plus 3 months of evidence-based movement training while the control group received botulinum toxin-A plus a handout of exercises. Primary outcomes were goal attainment (Goal Attainment Scale) and upper limb activity (Box and Block Test) at 12 months (ie, 9 months beyond the intervention). Secondary outcomes were spasticity, range of motion, strength, pain, burden of care, and health-related quality of life.ResultsBy 12 months, the experimental group scored the same as the control group on the Goal Attainment Scale (MD 0 T-score, 95% CI -5 to 5) and on the Box and Block Test (MD 0.01 blocks/s, 95% CI -0.01 to 0.03). There were no differences between groups on any secondary outcome.ConclusionAdditional intensive upper limb rehabilitation following botulinum toxin-A in chronic stroke survivors with a disabled upper limb is not more effective in the long-term.Trial RegistrationACTRN12615000616572 (12/06/2015).