Association between wrist-worn free-living accelerometry and hand grip strength in middle-aged and older adults.

INTRODUCTION: Wrist-worn activity monitors have seen widespread adoption in recent times, particularly in young and sport-oriented cohorts, while their usage among older adults has remained relatively low. The main limitations are in regards to the lack of medical insights that current mainstream activity trackers can provide to older subjects. One of the most important research areas under investigation currently is the possibility of extrapolating clinical information from these wearable devices. METHODS: The research question of this study is understanding whether accelerometry data collected for 7-days in free-living environments using a consumer-based wristband device, in conjunction with data-driven machine learning algorithms, is able to predict hand grip strength and possible conditions categorized by hand grip strength in a general population consisting of middle-aged and older adults. RESULTS: The results of the regression analysis reveal that the performance of the developed models is notably superior to a simple mean-predicting dummy regressor. While the improvement in absolute terms may appear modest, the mean absolute error (6.32 kg for males and 4.53 kg for females) falls within the range considered sufficiently accurate for grip strength estimation. The classification models, instead, excel in categorizing individuals as frail/pre-frail, or healthy, depending on the T-score levels applied for frailty/pre-frailty definition. While cut-off values for frailty vary, the results suggest that the models can moderately detect characteristics associated with frailty (AUC-ROC: 0.70 for males, and 0.76 for females) and viably detect characteristics associated with frailty/pre-frailty (AUC-ROC: 0.86 for males, and 0.87 for females). CONCLUSIONS: The results of this study can enable the adoption of wearable devices as an efficient tool for clinical assessment in older adults with multimorbidities, improving and advancing integrated care, diagnosis and early screening of a number of widespread diseases.

Automated region growing-based segmentation for trabecular bone structure in fresh-frozen human wrist specimens.

Bone strength depends on both mineral content and bone structure. Measurements of bone microstructure on specimens can be performed by micro-CT. In vivo measurements are reliably performed by high-resolution peripheral computed tomography (HR-pQCT) using dedicated software. In previous studies from our research group, trabecular bone properties on CT data of defatted specimens from many different CT devices have been analyzed using an Automated Region Growing (ARG) algorithm-based code, showing strong correlations to micro-CT.The aim of the study was to validate the possibility of segmenting and measuring trabecular bone structure from clinical CT data of fresh-frozen human wrist specimens. Data from micro-CT was used as reference. The hypothesis was that the ARG-based in-house built software could be used for such measurements.HR-pQCT image data at two resolutions (61 and 82 µm isotropic voxels) from 23 fresh-frozen human forearms were analyzed. Correlations to micro-CT were strong, varying from 0.72 to 0.99 for all parameters except trabecular termini and nodes. The bone volume fraction had correlations varying from 0.95 to 0.98 but was overestimated compared to micro-CT, especially at the lower resolution. Trabecular separation and spacing were the most stable parameters with correlations at 0.80-0.97 and mean values in the same range as micro-CT.Results from this in vitro study show that an ARG-based software could be used for segmenting and measuring 3D trabecular bone structure from clinical CT data of fresh-frozen human wrist specimens using micro-CT data as reference. Over-and underestimation of several of the bone structure parameters must however be taken into account.

Skeletal maturation evaluation: which is the reliability of dental calcification Demirjian method versus hand-wrist X-ray in growing subjects? A systematic review.

OBJECTIVES: This systematic review aimed at evaluating the reliability of dental maturation (DM) according to Demirjian method compared to hand and wrist maturation (HWM) to assess skeletal maturity (SM) in growing subjects, to identify the teeth and the corresponding mineralisation stages related to the pubertal growth spurt (PGS). MATERIALS AND METHODS: PubMed, Scopus, and Web of Science were systematically searched until January 5th, 2024, to identify observational cross-sectional studies that assessed the reliability of Demirjian method compared to the HWM methods (i.e., Grave and Brown and Fishman) in growing subjects. The quality assessment was evaluated using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist. RESULTS: Out of 136 papers suitable for title/abstract screening, 19 included studies. Of them, 17 papers showed the reliability of Demirjian DM method compared to HWM Fishman and Grave and Brown methods to assess SM in growing subjects. According to JBI Critical Appraisal Checklist, 12 papers were high-quality studies and 7 papers were medium-quality studies.  Conclusions: The mandibular second molar might be considered as the best indicator compared to other teeth and that the peak of growth occurs no earlier than stage F in females and stage G in males according to Demirjian method. Also, the mandibular canine might be analysed as indicator of SM in males, and results suggest that the peak of growth occurs no earlier than maturation stage F according to Demirjian method, only in male subjects. Further studies are needed to confirm these findings.

The use of accelerometer bracelets to evaluate arm motor function over a stroke rehabilitation period - an explorative observational study.

BACKGROUND: Assessments of arm motor function are usually based on clinical examinations or self-reported rating scales. Wrist-worn accelerometers can be a good complement to measure movement patterns after stroke. Currently there is limited knowledge of how accelerometry correlate to clinically used scales. The purpose of this study was therefore to evaluate the relationship between intermittent measurements of wrist-worn accelerometers and the patient's progression of arm motor function assessed by routine clinical outcome measures during a rehabilitation period. METHODS: Patients enrolled in in-hospital rehabilitation following a stroke were invited. Included patients were asked to wear wrist accelerometers for 24 h at the start (T1) and end (T2) of their rehabilitation period. On both occasions arm motor function was assessed by the modified Motor Assessment Scale (M_MAS) and the Motor Activity Log (MAL). The recorded accelerometry was compared to M_MAS and MAL. RESULTS: 20 patients were included, of which 18 completed all measurements and were therefore included in the final analysis. The resulting Spearman's rank correlation coefficient showed a strong positive correlation between measured wrist acceleration in the affected arm and M-MAS and MAL values at T1, 0.94 (p < 0.05) for M_MAS and 0.74 (p < 0.05) for the MAL values, and a slightly weaker positive correlation at T2, 0.57 (p < 0.05) for M_MAS and 0.46 - 0.45 (p = 0.06) for the MAL values. However, no correlation was seen for the difference between the two sessions. CONCLUSIONS: The results confirm that the wrist acceleration can differentiate between the affected and non-affected arm, and that there is a positive correlation between accelerometry and clinical measures. Many of the patients did not change their M-MAS or MAL scores during the rehabilitation period, which may explain why no correlation was seen for the difference between measurements during the rehabilitation period. Further studies should include continuous accelerometry throughout the rehabilitation period to reduce the impact of day-to-day variability.

Comparison of early clinical outcome in carpal tunnel release - mini-open technique with palmar incision vs. endoscopic technique with wrist crease incision.

BACKGROUND: The purpose of this study was to examine two techniques for Carpal Tunnel Syndrome, mini-Open Carpal Tunnel Release (mini-OCTR) and Endoscopic Carpal Tunnel Release (ECTR), to compare their therapeutic efficacy. METHODS: Sixteen patients who underwent mini-OCTR in palmar incision and 17 patients who underwent ECTR in the wrist crease incision were included in the study. All patients presented preoperatively and at 1, 3, and 6 months postoperatively and were assessed with the Visual Analogue Scale (VAS) and the Disabilities of Arm, Shoulder and Hand Score (DASH). We also assessed the pain and cosmetic VAS of the entire affected hand or surgical wound, and the patient's satisfaction with the surgery. RESULTS: In the objective evaluation, both surgical techniques showed improvement at 6 months postoperatively. The DASH score was significantly lower in the ECTR group (average = 3 months: 13.6, 6 months: 11.9) than in the mini-OCTR group (average = 3 months: 27.3, 6 months: 20.6) at 3 and 6 months postoperatively. Also, the pain VAS score was significantly lower in the ECTR group (average = 17.1) than in the mini-OCTR group (average = 36.6) at 3 months postoperatively. The cosmetic VAS was significantly lower in the ECTR group (average = 1 month: 15.3, 3 months: 12.2, 6 months: 5.41) than in the mini-OCTR group (average = 1 month: 33.3, 3 months: 31.2, 6 months: 24.8) at all time points postoperatively. Patient satisfaction scores tended to be higher in the ECTR group (average = 3.3) compared to the mini-OCTR group (average = 2.7). CONCLUSIONS: ECTR in wrist increase incision resulted in better pain and cosmetic recovery in an early postoperative phase compared with mini-OCTR in palmar incision. Our findings suggest that ECTR is an effective technique for patient satisfaction.

Perineural 5% dextrose versus corticosteroid injection in non-surgical carpal tunnel syndrom treatment.

Background and purpose:

We aimed to investigate the difference of clinical and electrophysiological improvement between perineural corticosteroid injection therapy (PCIT) and perineural 5% dextrose injection therapy (5%PDIT) in carpal tunnel syndrome (CTS).

Total of 92 wrists that were diagnosed as mild-to-moderate idiopathic CTS and completed their follow-up were included in our study. The severity of pain, symptom severity and functional status were asses­sed by visual analog scale (VAS) and the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) scores for treatment effectiveness. Randomized wrists were administered PCIT or 5%PDIT accompanied by ultrasound guidance. VAS, BCTQ scores and the electro­physiological study repeated before and after treatment at the 1st and 6th months after perineural injection therapies (PITs) were recorded.

Compared with baseline data, within groups there was significant improvement in VAS, BCTQ severity and function scores at 1st and 6th months follow-up (all p < 0.001). Considerable advance were detected in the median sensory nerve conduction velocity (SNCV) when pretreatment values were compared with posttreatment first month in both groups (p = 0.01; p < 0.001, respectively). No significant change occurred in median distal motor latency (DML) values between the 1st and 6th months in the groups (p = 0.095; p = 0.113, respectively). No significant difference was observed bet­ween 5%PDIT and PCIT groups.

Clinical and electrophysiologic improvement in CTS began from 1st month after PCIT and 5%PDIT. At the 6th month follow-up of the patients, 5%PDIT and PCIT had similar therapeutic effects. As a result, we can consider the replacement of PCIT with 5%PDIT in mild-to-moderate CTS patients especially in those who are hesitant because of the corticosteroid’s adverse effects.

Biomechanical Assessment Methods Used in Chronic Stroke: A Scoping Review of Non-Linear Approaches.

Non-linear and dynamic systems analysis of human movement has recently become increasingly widespread with the intention of better reflecting how complexity affects the adaptability of motor systems, especially after a stroke. The main objective of this scoping review was to summarize the non-linear measures used in the analysis of kinetic, kinematic, and EMG data of human movement after stroke. PRISMA-ScR guidelines were followed, establishing the eligibility criteria, the population, the concept, and the contextual framework. The examined studies were published between 1 January 2013 and 12 April 2023, in English or Portuguese, and were indexed in the databases selected for this research: PubMed®, Web of Science®, Institute of Electrical and Electronics Engineers®, Science Direct® and Google Scholar®. In total, 14 of the 763 articles met the inclusion criteria. The non-linear measures identified included entropy (n = 11), fractal analysis (n = 1), the short-term local divergence exponent (n = 1), the maximum Floquet multiplier (n = 1), and the Lyapunov exponent (n = 1). These studies focused on different motor tasks: reaching to grasp (n = 2), reaching to point (n = 1), arm tracking (n = 2), elbow flexion (n = 5), elbow extension (n = 1), wrist and finger extension upward (lifting) (n = 1), knee extension (n = 1), and walking (n = 4). When studying the complexity of human movement in chronic post-stroke adults, entropy measures, particularly sample entropy, were preferred. Kinematic assessment was mainly performed using motion capture systems, with a focus on joint angles of the upper limbs.

Injury Risk Functions for the Midsized Male Wrist and Elbow as a Result of Behind Shield Blunt Trauma.

Ballistic shields protect users from a variety of threats, including projectiles. Shield back-face deformation (BFD) is the result of the shield deflecting or absorbing a projectile and deforming toward the user. Back-face deformation can result in localized blunt loading to the upper extremity, where the shield is supported by the user. Two vulnerable locations along the upper extremity were investigated-the wrist and elbow-on eight postmortem human subjects (PMHS) using a pneumatic impacting apparatus for investigating the fracture threshold as a result of behind shield blunt trauma (BSBT). Impacting parameters were established by subjecting an augmented WorldSID anthropomorphic test device (ATD) positioned behind a ballistic shield to ballistic impacts. These data were used to form the impact parameters applied to PMHS, where the wrist most frequently fractured at the distal radius and the elbow most frequently fractured at the radial head. The fracture threshold for the wrist was 5663±1386 N (mean±standard deviation), higher than the elbow at 4765±894 N (though not significantly, p = 0.15). The failure impact velocity for wrist impacts was 17.7±2.1 m/s, while for the elbow, the failure impact velocity was 19.5±0.9 m/s. An approximate 10% risk of fracture threshold was identified on the modified WorldSID ATD (no flesh analogue included) to inform future protective standards.

Chemical uptake into silicone wristbands over a five day period.

Silicone wristbands are a noninvasive personal exposure assessment tool. However, despite their utility, questions remain about the rate at which chemicals accumulate on wristbands when worn, as validation studies utilizing wristbands worn by human participants are limited. This study evaluated the chemical uptake rates of 113 organic pollutants from several chemical classes (i.e., polychlorinated biphenyls (PCB), organophosphate esters (OPEs), alkyl OPEs, polybrominated diphenyl ethers (PBDEs), brominated flame retardants (BFR), phthalates, pesticides, and polycyclic aromatic hydrocarbons (PAHs) over a five-day period. Adult participants (n = 10) were asked to wear five silicone wristbands and then remove one wristband each day. Several compounds were detected in all participants' wristbands after only one day. The number of chemicals detected frequently (i.e. in at least seven participants wristbands) increased from 20% of target compounds to 26% after three days and more substantially increased to 34% of target compounds after four days of wear. Chemicals detected in at least seven participants' day five wristbands (n = 24 chemicals) underwent further statistical analysis, including estimating the chemical uptake rates over time. Some chemicals, including pesticides and phthalates, had postive and significant correlations between concentrations on wristbands worn five days and concentrations of wristbands worn fewer days suggesting chronic exposure. For 23 of the 24 compounds evaluated there was a statistically significant and positive linear association between the length of time wristbands were worn and chemical concentrations in wristbands. Despite the differences that exist between laboratory studies using polydimethylsiloxane (PDMS) environmental samplers and worn wristbands, these results indicate that worn wristbands are primarily acting as first-order kinetic samplers. These results suggest that studies using different deployment lengths should be comparable when results are normalized to the length of the deployment period. In addition, a shorter deployment period could be utilized for compounds that were commonly detected in as little as one day.

Is Ultrasonography a Reliable Approach for the Evaluation of Carpal Tunnel Syndrome in Patients With Mucopolysaccharidosis?

BACKGROUND: One of the most common causes of carpal tunnel syndrome (CTS) in childhood is mucopolysaccharidosis (MPS). While ultrasonography (US) can aid in the diagnosis of CTS in adult patients, there is limited experience of this in the pediatric group. We aimed to investigate the results of wrist ultrasonography, which may be a candidate alternative to electrophysiological examination. METHODS: The participants were evaluated for symptoms, physical examination findings, electrophysiological tests and grayscale US. CTS was diagnosed in accordance with the American Academy of Orthopedic Surgeons Management of Carpal Tunnel Syndrome: Evidence-Based Clinical Practice Guideline. RESULTS: Included in the study were 27 MPS patients aged 4.5-32 years and 30 healthy control subjects aged 4.3-26 years. Of the 54 wrists in the MPS group, 30 were diagnosed with CTS. The median cross-sectional area (CSA) at the proximal carpal tunnel, the CSA at the forearm, and the wrist-forearm ratio (WFR) were higher in the wrists of the MPS with CTS group than in those without CTS and the healthy control subjects. The WFR cutoff of ≥1.35, 56.6% (95% CI: 437.4-74.5) sensitivity, and 89.8% (95% CI: 81.0-95.5) specificity were consistent with a diagnosis of CTS (receiver operating characteristics analysis, area under the curve = 0.775, 95% CI: 0.673-0.877). CONCLUSION: Although the US provides results with unsatisfactory specificity and sensitivity, it is a candidate for further investigation for the diagnosis of CTS because it is an innovative, noninvasive, and more accessible method. WFR value may produce more meaningful results than wrist or forearm nerve area measurements.

Illusory Directional Sensation Induced by Asymmetric Vibrations Influences Sense of Agency and Velocity in Wrist Motions.

Illusory directional sensations are generated through asymmetric vibrations applied to the fingertips and have been utilized to induce upper-limb motions in the rehabilitation and training of patients with visual impairment. However, its effects on motor control remain unclear. This study aimed to verify the effects of illusory directional sensations on wrist motion. We conducted objective and subjective evaluations of wrist motion during a motor task, while inducing an illusory directional sensation that was congruent or incongruent with wrist motion. We found that, when motion and illusory directional sensations were congruent, the sense of agency for motion decreased. This indicates an induction sensation of the hand being moved by the illusion. Interestingly, although no physical force was applied to the hand, the angular velocity of the wrist was higher in the congruent condition than that in the no-stimulation condition. The angular velocity of the wrist and electromyography signals of the agonist muscles were weakly positively correlated, suggesting that the participants may have increased their wrist velocity. In other words, the congruence between the direction of motion and illusory directional sensation induced the sensation of the hand being moved, even though the participants' wrist-motion velocity increased. This phenomenon can be explained by the discrepancy between the sensation of active motion predicted by the efferent copy, and that of actual motion caused by the addition of the illusion. The findings of this study can guide the design of novel rehabilitation methods.

Research hotspots and trend of wrist arthroscopy: A bibliometrics analysis from 2013 to 2023.

BACKGROUND: Wrist arthroscopy technology is a surgical technology invented in recent years and widely used in clinical treatment of various wrist diseases. This study uses the methods of bibliometrics and visual analysis to understand the global research status, research hotspots, and future development trends of wrist arthroscopy. METHODS: The relevant literature of global publications on wrist arthroscopy from 2013 to 2023 was extracted from the Web of Science Core Collection database, and the annual output, cooperation, hot spots, research status, and development trend of this field were analyzed by using the bibliometric software (VOSviewers, CiteSpace, and the R package "Bibliometrix"). RESULTS: A total of 635 articles were included, from 2013 to 2023, the number of publications related to wrist arthroscopy showed an overall upward trend, the USA, France, and China are the top 3 countries in terms of the number of publications, whereas Mayo Clinic is the institution with the highest number of publications, Ho PC holds a core position in this field, keyword analysis indicates that the research hotspots are the applications of wrist arthroscopy in triangular fibrocartilage complex injuries, scaphoid nonunion, and avascular necrosis of the lunate. CONCLUSION SUBSECTIONS: Wrist arthroscopy has shown tremendous potential in treating various wrist diseases. However, there are still some challenges in its research domain. With continuous deep research, strengthened international collaboration, and ongoing technological advancements, wrist arthroscopy has the potential to become the standard treatment in hand surgery, offering more efficient and safer treatment options for patients worldwide.

Development of sensor system and data analytic framework for non-invasive blood glucose prediction.

Periodic quantification of blood glucose levels is performed using painful, invasive methods. The proposed work presents the development of a noninvasive glucose-monitoring device with two sensors, i.e., finger and wrist bands. The sensor system was designed with a near-infrared (NIR) wavelength of 940 nm emitter and a 900-1700 nm detector. This study included 101 diabetic and non-diabetic volunteers. The obtained dataset was subjected to pre-processing, exploratory data analysis (EDA), data visualization, and integration methods. Ambiguities such as the effects of skin color, ambient light, and finger pressure on the sensor were overcome in the proposed 'niGLUC-2.0v'. niGLUC-2.0v was validated with performance metrics where accuracy of 99.02%, mean absolute error (MAE) of 0.15, mean square error (MSE) of 0.22 for finger, and accuracy of 99.96%, MAE of 0.06, MSE of 0.006 for wrist prototype with ridge regression (RR) were achieved. Bland-Altman analysis was performed, where 98% of the data points were within ± 1.96 standard deviation (SD), 100% were under zone A of the Clarke Error Grid (CEG), and statistical analysis showed p < 0.05 on evaluated accuracy. Thus, niGLUC-2.0v is suitable in the medical and personal care fields for continuous real-time blood glucose monitoring.

Development and Evaluation of a Hybrid Measurement System to Determine the Kinematics of the Wrist.

Optical Motion Capture Systems (OMCSs) are considered the gold standard for kinematic measurement of human movements. However, in situations such as measuring wrist kinematics during a hairdressing activity, markers can be obscured, resulting in a loss of data. Other measurement methods based on non-optical data can be considered, such as magneto-inertial measurement units (MIMUs). Their accuracy is generally lower than that of an OMCS. In this context, it may be worth considering a hybrid system [MIMU + OMCS] to take advantage of OMCS accuracy while limiting occultation problems. The aim of this work was (1) to propose a methodology for coupling a low-cost MIMU (BNO055) to an OMCS in order to evaluate wrist kinematics, and then (2) to evaluate the accuracy of this hybrid system [MIMU + OMCS] during a simple hairdressing gesture. During hair cutting gestures, the root mean square error compared with the OMCS was 4.53° (1.45°) for flexion/extension, 5.07° (1.30°) for adduction/abduction, and 3.65° (1.19°) for pronation/supination. During combing gestures, they were significantly higher, but remained below 10°. In conclusion, this system allows for maintaining wrist kinematics in case of the loss of hand markers while preserving an acceptable level of precision (<10°) for ergonomic measurement or entertainment purposes.

A machine-learning method isolating changes in wrist kinematics that identify age-related changes in arm movement.

Normal aging often results in an increase in physiological tremors and slowing of the movement of the hands, which can impair daily activities and quality of life. This study, using lightweight wearable non-invasive sensors, aimed to detect and identify age-related changes in wrist kinematics and response latency. Eighteen young (ages 18-20) and nine older (ages 49-57) adults performed two standard tasks with wearable inertial measurement units on their wrists. Frequency analysis revealed 5 kinematic variables distinguishing older from younger adults in a postural task, with best discrimination occurring in the 9-13 Hz range, agreeing with previously identified frequency range of age-related tremors, and achieving excellent classifier performance (0.86 AUROC score and 89% accuracy). In a second pronation-supination task, analysis of angular velocity in the roll axis identified a 71 ms delay in initiating arm movement in the older adults. This study demonstrates that an analysis of simple kinematic variables sampled at 100 Hz frequency with commercially available sensors is reliable, sensitive, and accurate at detecting age-related increases in physiological tremor and motor slowing. It remains to be seen if such sensitive methods may be accurate in distinguishing physiological tremors from tremors that occur in neurological diseases, such as Parkinson's Disease.

A Low-Cost Wearable Device to Estimate Body Temperature Based on Wrist Temperature.

The remote monitoring of vital signs and healthcare provision has become an urgent necessity due to the impact of the COVID-19 pandemic on the world. Blood oxygen level, heart rate, and body temperature data are crucial for managing the disease and ensuring timely medical care. This study proposes a low-cost wearable device employing non-contact sensors to monitor, process, and visualize critical variables, focusing on body temperature measurement as a key health indicator. The wearable device developed offers a non-invasive and continuous method to gather wrist and forehead temperature data. However, since there is a discrepancy between wrist and actual forehead temperature, this study incorporates statistical methods and machine learning to estimate the core forehead temperature from the wrist. This research collects 2130 samples from 30 volunteers, and both the statistical least squares method and machine learning via linear regression are applied to analyze these data. It is observed that all models achieve a significant fit, but the third-degree polynomial model stands out in both approaches. It achieves an R2 value of 0.9769 in the statistical analysis and 0.9791 in machine learning.

A New Wrist-Worn Tool Supporting the Diagnosis of Parkinsonian Motor Syndromes.

To date, clinical expert opinion is the gold standard diagnostic technique for Parkinson's disease (PD), and continuous monitoring is a promising candidate marker. This study assesses the feasibility and performance of a new wearable tool for supporting the diagnosis of Parkinsonian motor syndromes. The proposed method is based on the use of a wrist-worn measuring system, the execution of a passive, continuous recording session, and a computation of two digital biomarkers (i.e., motor activity and rest tremor index). Based on the execution of some motor tests, a second step is provided for the confirmation of the results of passive recording. In this study, fifty-nine early PD patients and forty-one healthy controls were recruited. The results of this study show that: (a) motor activity was higher in controls than in PD with slight tremors at rest and did not significantly differ between controls and PD with mild-to-moderate tremor rest; (b) the tremor index was smaller in controls than in PD with mild-to-moderate tremor rest and did not significantly differ between controls and PD patients with slight tremor rest; (c) the combination of the said two motor parameters improved the performances in differentiating controls from PD. These preliminary findings demonstrate that the combination of said two digital biomarkers allowed us to differentiate controls from early PD.

A usability study on mobile EMG-guided wrist extension training in subacute stroke patients-MyoGuide.

BACKGROUND: Effective stroke rehabilitation requires high-dose, repetitive-task training, especially during the early recovery phase. However, the usability of upper-limb rehabilitation technology in acute and subacute stroke survivors remains relatively unexplored. In this study, we introduce subacute stroke survivors to MyoGuide, a mobile training platform that employs surface electromyography (sEMG)-guided neurofeedback training that specifically targets wrist extension. Notably, the study emphasizes evaluating the platform's usability within clinical contexts. METHODS: Seven subacute post-stroke patients (1 female, mean age 53.7 years, mean time post-stroke 58.9 days, mean duration per training session 48.9 min) and three therapists (one for eligibility screening, two for conducting training) participated in the study. Participants underwent ten days of supervised one-on-one wrist extension training with MyoGuide, which encompassed calibration, stability assessment, and dynamic tasks. All training records including the Level of Difficulty (LoD) and Stability Assessment Scores were recorded within the application. Usability was assessed through the System Usability Scale (SUS) and participants' willingness to continue home-based training was gauged through a self-developed survey post-training. Therapists also documented the daily performance of participants and the extent of support required. RESULTS: The usability analysis yielded positive results, with a median SUS score of 82.5. Compared to the first session, participants significantly improved their performance at the final session as indicated by both the Stability Assessment Scores (p = 0.010, mean = 229.43, CI = [25.74-433.11]) and the LoD (p < 0.001; mean: 45.43, CI: [25.56-65.29]). The rate of progression differed based on the initial impairment levels of the patient. After training, participants expressed a keen interest in continuing home-based training. However, they also acknowledged challenges related to independently using the Myo armband and software. CONCLUSIONS: This study introduces the MyoGuide training platform and demonstrates its usability in a clinical setting for stroke rehabilitation, with the assistance of a therapist. The findings support the potential of MyoGuide for wrist extension training in patients across a wide range of impairment levels. However, certain usability challenges, such as donning/doffing the armband and navigating the application, need to be addressed to enable independent MyoGuide training requiring only minimal supervision by a therapist.

Technical-tactical behavior analysis of general duty police officers during non-compliant suspect apprehensions: A novel approach to establish minimum force requirements.

BACKGROUND: While effective apprehensions of non-compliant suspects are central to public safety, the minimal force needed to transition a suspect from standing to the ground, vital for apprehension success, has not been established. OBJECTIVE: To examine the technical-tactical behaviors of general duty police officers during simulated apprehensions and quantify the minimum force required to destabilize non-compliant suspects. METHODS: Task simulations conducted with 91 officers were analyzed to identify common grappling movements, strikes, control tactics, and changes in body posture. A separate assessment of 55 male officers aimed to determine the minimum force required for destabilization in five body regions (wrist, forearm, shoulder, mid-chest, and mid-back). Data are presented as mean±standard deviation. RESULTS: On average, apprehensions took 7.3±3.2 seconds. While all officers used grappling movements (100%) and the majority employed control tactics (75%), strikes were seldom used (4%). Apprehensions typically began with a two-handed pull (97%; Contact Phase), 55% then attempted an arm bar takedown, followed by a two-handed cross-body pull (68%; Transition/Control Phase), and a two-handed push to the ground (19%; Ground Phase). All officers began in the upright posture, with most shifting to squat (75%), kneel (58%), or bent (45%) postures to complete the apprehension. The minimum force required to disrupt balance differed across body regions (wrist: 54±12 kg; forearm: 49±12 kg; shoulder: 42±10 kg; mid-chest: 44±11 kg; mid-back: 30±7 kg, all P < 0.05), except between the shoulder and chest (P = 0.19). CONCLUSION: These findings provide insights that can enhance the design and accuracy of future apprehension evaluations and inform the optimization of law enforcement physical employment standards.