The influence of oral contraceptives on the exercise pressor reflex in the upper and lower body.

Previous research has demonstrated that oral contraceptive (OC) users have enhanced cardiorespiratory responses to arm metaboreflex activation (i.e., postexercise circulatory occlusion, PECO) and attenuated pressor responses to leg passive movement (PM) compared to non-OC users (NOC). We investigated the cardiorespiratory responses to arm or leg metaboreflex and mechanoreflex activation in 32 women (OC, n = 16; NOC, n = 16) performing four trials: 40% handgrip or 80% plantarflexion followed by PECO and arm or leg PM. OC and NOC increased mean arterial pressure (MAP) similarly during handgrip, plantarflexion and arm/leg PECO compared to baseline. Despite increased ventilation (VE) during exercise, none of the women exhibited higher VE during arm or leg PECO. OC and NOC similarly increased MAP and VE during arm or leg PM compared to baseline. Therefore, OC and NOC were similar across pressor and ventilatory responses to arm or leg metaboreflex and mechanoreflex activation. However, some differences due to OC may have been masked by disparities in muscle strength. Since women increase VE during exercise, we suggest that while women do not display a ventilatory response to metaboreflex activation (perhaps due to not reaching a theoretical metabolite threshold to stimulate VE), the mechanoreflex may drive VE during exercise in women.

Mid-upper arm circumference predicts the risk of gestational diabetes in early pregnancy.

BACKGROUND: The present work aimed to assess the value of mid-upper arm circumference (MUAC) at 8 to 12 weeks in predicting the occurrence of gestational diabetes mellitus (GDM). METHODS: According to eligibility criteria, 328 women with singleton pregnancies who underwent routine antenatal check-ups at Qinhuangdao Maternal and Child Health Hospital from September 2017 to September 2020 were included. The patients were divided into the gestational diabetes mellitus (GDM) and non-GDM groups according to oral glucose tolerance test (OGTT) data from gestation weeks 24 to 28. Clinical data were compared between the two groups. Logistic regression analysis was performed to determine factors independently predicting GDM. Receiver operating characteristic (ROC) curve analysis was employed to analyze the value of MUAC in predicting the occurrence of GDM. The optimal cut-off points were calculated. RESULTS: In logistic regression analysis, pre-pregnancy weight, waist circumference, MUAC, UA, TG, and HDL-C independently predicted the occurrence of GDM (P < 0.05). MUAC retained statistical significance upon adjustment for various confounders (OR = 8.851, 95%CI: 3.907-20.048; P < 0.001). ROC curve analysis revealed good diagnostic potential for MUAC in GDM (AUC = 0.742, 95%CI: 0.684-0.800, P < 0.001), with a cut-off of 28.5 cm, sensitivity and specificity were 61% and 77%, respectively. CONCLUSION: Pregnant women with MUAC >28.5 cm are prone to develop GDM during pregnancy, indicating that MUAC as an important predictive factor of GDM in early pregnancy.

IMU Data-Driven and PCA-Based Approach to Establish Quantifiable and Practically Applicable Measures for V2 Technique Elements in Cross-Country Skiing.

Quantifying movement coordination in cross-country (XC) skiing, specifically the technique with its elemental forms, is challenging. Particularly, this applies when trying to establish a bidirectional transfer between scientific theory and practical experts' knowledge as expressed, for example, in ski instruction curricula. The objective of this study was to translate 14 curricula-informed distinct elements of the V2 ski-skating technique (horizontal and vertical posture, lateral tilt, head position, upper body rotation, arm swing, shoulder abduction, elbow flexion, hand and leg distance, plantar flexion, ski set-down, leg push-off, and gliding phase) into plausible, valid and applicable measures to make the technique training process more quantifiable and scientifically grounded. Inertial measurement unit (IMU) data of 10 highly experienced XC skiers who demonstrated the technique elements by two extreme forms each (e.g., anterior versus posterior positioning for the horizontal posture) were recorded. Element-specific principal component analyses (PCAs)-driven by the variance produced by the technique extremes-resulted in movement components that express quantifiable measures of the underlying technique elements. Ten measures were found to be sensitive in distinguishing between the inputted extreme variations using statistical parametric mapping (SPM), whereas for four elements the SPM did not detect differences (lateral tilt, plantar flexion, ski set-down, and leg push-off). Applicability of the established technique measures was determined based on quantifying individual techniques through them. The study introduces a novel approach to quantitatively assess V2 ski-skating technique, which might help to enhance technique feedback and bridge the communication gap that often exists between practitioners and scientists.

Validation of a novel professional automated auscultatory upper-arm cuff blood pressure monitor in a general population according to the AAMI/ESH/ISO Universal Standard: KOROT V2 Doctor (InBody BPBIO280KV).

OBJECTIVE: A novel automated auscultatory upper arm cuff blood pressure (BP) monitor KOROT V2 Doctor (InBody BPBIO280KV) was developed for professional use. An electronic stethoscope embedded in the device cuff records the Korotkoff sounds, which are graphically displayed during deflation allowing visual evaluation by the healthcare professional. The device provides automated measurements of BP and this study evaluated its accuracy. METHODS: The requirements of the Association for the Advancement of Medical Instrumentation/European Society of Hypertension/International Organization for Standardization (AAMI/ESH/ISO) Universal Standard (ISO 81060-2:2018) and its Amendment 1.2020-01 were applied. Participants were recruited to fulfill the age, sex, BP, arm circumference, and cuff distribution criteria of the Universal Standard and its Amendment in a general population using the same arm sequential measurement method. Three cuffs of the test device were tested for arm circumference 23-28, 28-35, and 33-42 cm. RESULTS: Data from 85 individuals were analyzed [mean age: 56.4 ±â€…16.0 (SD) years, 50 men, arm circumference 23-42 cm]. For validation Criterion 1, the mean difference ±SD between the test device and reference BP readings (N = 255) was -1.3 ± 6.0/1.5 ± 5.0 mmHg (systolic/diastolic; threshold ≤5 ±â€…8 mmHg). For Criterion 2, the SD of the averaged BP differences per individual (N = 85) was 4.61/3.48 mmHg (systolic/diastolic; threshold ≤6.82/6.78 mmHg). CONCLUSION: The KOROT V2 Doctor (InBody BPBIO280KV) device for professional use, which provides automated auscultatory measurements with visual display of the Korotkoff sounds, comfortably fulfills all the requirements of the AAMI/ESH/ISO Universal Standard (ISO 81060-2:2018) in a general population and can be recommended for clinical use.

Incidental Breast Cancer Diagnosis From Lymphoscintography Using 99mTc-Labeled Nanocolloid for Cutaneous Melanoma of the Upper Arm.

ABSTRACT: A 51-year-old woman with a 2-mm-Breslow-thickness melanoma on her arm had 99mTc-nanocolloid lymphoscintigraphy to localize the associated sentinel lymph node. A single axillary node was identified, and histology confirmed a micrometastasis of breast tissue origin. Imaging of the patient's breasts and subsequent biopsy confirmed ipsilateral stage III breast cancer, which was treated with lumpectomy and axillary node clearance. This is the first reported case of an incidental solid cancer diagnosis from a sentinel lymph node biopsy undertaken for a different tumor origin. This illustrates the importance of recognizing overlapping lymphatic distribution of sentinel lymph nodes, which can drain multiple organs.

Inter-observer reliability and anatomical landmarks for arm circumference to determine cuff size for blood pressure measurement.

Accurate arm circumference (AC) measurement is required for accurate blood pressure (BP) readings. Standards stipulate measuring arm circumference at the midpoint between the acromion process (AP) and the olecranon process. However, which part of the AP to use is not stipulated. Furthermore, BP is measured sitting but arm circumference is measured standing. We sought to understand how landmarking during AC measurement and body position affect cuff size selection. Two variations in measurement procedure were studied. First, AC was measured at the top of the acromion (TOA) and compared to the spine of the acromion (SOA). Second, standing versus seated measurements using each landmark were compared. AC was measured to the nearest 0.1 cm at the mid-point of the upper arm by two independent observers, blinded from each other's measurements. In 51 participants, the mean (±SD) mid-AC measurement using the anchoring landmarks TOA and SOA in the standing position were 32.4 cm (±6.18) and 32.1 cm (±6.07), respectively (mean difference of 0.3 cm). In the seated position, mean arm circumference was 32.2 (±6.10) using TOA and 31.1 (±6.03) using SOA (mean difference 1.1 cm). Kappa agreement for cuff selection in the standing position between TOA and SOA was 0.94 (p < 0.001). The landmark on the acromion process can change the cuff selection in a small percentage of cases. The overall impact of this landmark selection is small. However, standardizing landmark selection and body position for AC measurement could further reduce variability in cuff size selection during BP measurement and validation studies.

Enhanced Muscle Activation Using Robotic Assistance Within the Electromechanical Delay: Implications for Rehabilitation?

Robotic rehabilitation has been shown to match the effects of conventional physical therapy on motor function for patients with neurological diseases. Rehabilitation robots have the potential to reduce therapists' workload in time-intensive training programs as well as perform actions that are not replicable by human therapists. We investigated the effects of one such modality that cannot be achieved by a human therapist: assistance and resistance within the electromechanical delay between muscle activation and muscle contraction during arm extension. We found increased muscle activation when providing robotic assistance within this electromechanical delay. Assistance provided within this delay moves the participant's arm quicker than their own muscle and increases the subsequent peak voluntary muscle activation compared to normal arm extension by 68.97 ± 80.05 % (SE = 0.021; p = 0.007 ). This is surprising since all previous literature shows that muscle activation either decreases or does not change when participants receive robotic assistance. As a consequence, traditional robotic rehabilitation incrementally reduces assistance as the patient improves to maintain levels of muscle activation which is suggested to be important for neuronal repair. The present result may enable therapists to no longer have to choose between providing assistance or increasing muscle activation. Instead, therapists may be able to provide assistance while also increasing muscle activation.

Association between the arm circumference and non-alcoholic fatty liver disease in American children and adolescence: a population-based analysis.

Background: The arm circumference (AC) has been used as an important tool to access the risk of non-alcoholic fatty liver disease (NAFLD) in adults. However, the association between AC and NAFLD in children and adolescence remains unclear. This study aims to explore the relationship between AC and NAFLD in American children and adolescence. Methods: 2017-2020 National Health and Nutrition Examination Survey (NHANES) was used to carry out the cross-sectional study. The association between AC and the risk of NAFLD, and liver steatosis was analyzed using weighted multivariable logistic regression and multivariate linear regression. Additionally, a two-part linear regression model was used to identify threshold effects in this study. Subgroup analysis, interaction tests and receiver operating characteristic (ROC) curve analysis were also carried out. Results: A total of 1,559 children and adolescence aged 12-18 years old were included, and the prevalence of NAFLD was 27.3%. AC was positively correlated with the risk of NAFLD (OR = 1.25, 95% CI: 1.19, 1.32) and liver steatosis (ß = 4.41, 95% CI: 3.72, 5.09). Subgroup analysis stratified by age and race showed a consistent positive correlation. A non-linear relationship and saturation effect between AC and NAFLD risk were identified, with an S shaped curve and an inflection point at 34.5 cm. Area under the ROC of AC to NAFLD was 0.812, with the sensitivity of 67.6%, the specificity of 83.8% and the cutoff value of 31.7 cm. Conclusion: Our study shows that AC is independently correlated with an increased risk of NAFLD and the severity of liver steatosis in American children and adolescence.

[Expert consensus on the whole-course management of implantable venous access port in the upper arm of cancer patients (2024 edition)].

As one of a major public health issue in China, the number of new cases and deaths of malignant tumors has been climbing year by year. Implantable venous access port (IVAP) is used as a safe infusion route in the treatment of malignant tumor patients such as infusion of antitumor drugs and intravenous nutrition. With the widespread application of ultrasound-guided Sedinger puncture techniques and intracardiac electrocardiogram positioning technology, IVAP in the upper arm has been recognized by the majority of medical personnel and cancer patients due to its advantages of hiding scars and completely avoiding the risk of hemothorax and pneumothorax. In order to standardize the clinical application of IVAP via the upper arm approach in cancer patients, improve the success rate of implantation, reduce complications and improve patient satisfaction, the Breast Cancer Expert Committee of the National Cancer Quality Control Center consulted guidelines and the latest evidence-based evidences and established the expert consensus on the whole-course management of implantable venous access port in the upper arm of cancer patients through literature research and expert discussions, in order to provide reference for the standard application of IVAP in the upper arm. The consensus mainly introduces the indications, contraindications, preoperative evaluation, implantation site, operation procedure, utilization and maintenance, complications and management, medical staff training and patient education of IVAP in the upper arm, in order to provide reference for clinical staff.

Visuomotor coordination with gaze, head and arm movements during table tennis forehand rallies.

The purpose of this study was to clarify the temporal coordination between gaze, head, and arm movements during forehand rallies in table tennis. Collegiate male table tennis players (n = 7) conducted forehand rallies at a constant tempo (100, 120, and 150 bpm) using a metronome. In each tempo condition, participants performed 30 strokes (a total of 90 strokes). Gaze, head, and dominant arm (shoulder, elbow, and wrist) movements were recorded with an eye-tracking device equipped with a Gyro sensor and a 3-D motion capture system. The results showed that the effect of head movements relative to gaze movements was significantly higher than that of eye movements in the three tempo conditions. Our results indicate that head movements are closely associated with gaze movements during rallies. Furthermore, cross-correlation coefficients (CCs) between head and arm movements were more than 0.96 (maximum coefficient: 0.99). In addition, head and arm movements were synchronized during rallies. Finally, CCs between gaze and arm movements were more than 0.74 (maximum coefficient: 0.99), indicating that gaze movements are temporally coordinated with arm movements. Taken together, head movements could play important roles not only in gaze tracking but also in the temporal coordination with arm movements during table tennis forehand rallies.

Mitigating Trunk Compensatory Movements in Post-Stroke Survivors through Visual Feedback during Robotic-Assisted Arm Reaching Exercises.

Trunk compensatory movements frequently manifest during robotic-assisted arm reaching exercises for upper limb rehabilitation following a stroke, potentially impeding functional recovery. These aberrant movements are prevalent among stroke survivors and can hinder their progress in rehabilitation, making it crucial to address this issue. This study evaluated the efficacy of visual feedback, facilitated by an RGB-D camera, in reducing trunk compensation. In total, 17 able-bodied individuals and 18 stroke survivors performed reaching tasks under unrestricted trunk conditions and visual feedback conditions. In the visual feedback modalities, the target position was synchronized with trunk movement at ratios where the target moved at the same speed, double, and triple the trunk's motion speed, providing real-time feedback to the participants. Notably, trunk compensatory movements were significantly diminished when the target moved at the same speed and double the trunk's motion speed. Furthermore, these conditions exhibited an increase in the task completion time and perceived exertion among stroke survivors. This outcome suggests that visual feedback effectively heightened the task difficulty, thereby discouraging unnecessary trunk motion. The findings underscore the pivotal role of customized visual feedback in correcting aberrant upper limb movements among stroke survivors, potentially contributing to the advancement of robotic-assisted rehabilitation strategies. These insights advocate for the integration of visual feedback into rehabilitation exercises, highlighting its potential to foster more effective recovery pathways for post-stroke individuals by minimizing undesired compensatory motions.

Gait Variability as a Potential Motor Marker of Cerebellar Disease-Relationship between Variability of Stride, Arm Swing and Trunk Movements, and Walking Speed.

Excessive stride variability is a characteristic feature of cerebellar ataxias, even in pre-ataxic or prodromal disease stages. This study explores the relation of variability of arm swing and trunk deflection in relationship to stride length and gait speed in previously described cohorts of cerebellar disease and healthy elderly: we examined 10 patients with spinocerebellar ataxia type 14 (SCA), 12 patients with essential tremor (ET), and 67 healthy elderly (HE). Using inertial sensors, recordings of gait performance were conducted at different subjective walking speeds to delineate gait parameters and respective coefficients of variability (CoV). Comparisons across cohorts and walking speed categories revealed slower stride velocities in SCA and ET patients compared to HE, which was paralleled by reduced arm swing range of motion (RoM), peak velocity, and increased CoV of stride length, while no group differences were found for trunk deflections and their variability. Larger arm swing RoM, peak velocity, and stride length were predicted by higher gait velocity in all cohorts. Lower gait velocity predicted higher CoV values of trunk sagittal and horizontal deflections, as well as arm swing and stride length in ET and SCA patients, but not in HE. These findings highlight the role of arm movements in ataxic gait and the impact of gait velocity on variability, which are essential for defining disease manifestation and disease-related changes in longitudinal observations.

Comparison of supraclavicular block with infraclavicular block for distal arm surgeries: A meta-analysis of randomized controlled studies.

BACKGROUND: Supraclavicular and infraclavicular nerve block are commonly used for the analgesia of distal arm surgeries, and this meta-analysis aims to compare their analgesic efficacy for distal arm surgeries. METHODS: We searched several databases including PubMed, Embase, Web of Science, EBSCO, and Cochrane library databases, and selected the randomized controlled trials exploring the analgesic efficacy of supraclavicular block versus infraclavicular block for distal arm surgeries. This meta-analysis was conducted using the random-effect or fixed-effect model based on the heterogeneity. RESULTS: Six randomized controlled trials were included in this meta-analysis. Compared with infraclavicular nerve block for distal arm surgeries, supraclavicular nerve block was associated with substantially reduced complete sensory block (odds ratio [OR] = 0.41; 95% confidence interval [CI] = 0.19-0.88; P = .02) and block performance time (standard mean difference [SMD] = -3.06; 95% CI = -5.82--0.31; P = .03), but had no effect on duration of analgesia (SMD = -0.15; 95% CI = -0.49-0.18; P = .36), time to sensory block (SMD = -0.41; 95% CI = -2.28-1.47; P = .67), vascular puncture (OR = 1.03; 95% CI = 0.11-10.05; P = .98) or adverse events (OR = 0.70; 95% CI = 0.12-4.04; P = .69). CONCLUSIONS: Infraclavicular nerve block may be superior to supraclavicular nerve block for the analgesia of distal arm surgeries but needs increased block performance time.

A Multimodal Assistive-Robotic-Arm Control System to Increase Independence After Tetraplegia.

Following tetraplegia, independence for completing essential daily tasks, such as opening doors and eating, significantly declines. Assistive robotic manipulators (ARMs) could restore independence, but typically input devices for these manipulators require functional use of the hands. We created and validated a hands-free multimodal input system for controlling an ARM in virtual reality using combinations of a gyroscope, eye-tracking, and heterologous surface electromyography (sEMG). These input modalities are mapped to ARM functions based on the user's preferences and to maximize the utility of their residual volitional capabilities following tetraplegia. The two participants in this study with tetraplegia preferred to use the control mapping with sEMG button functions and disliked winking commands. Non-disabled participants were more varied in their preferences and performance, further suggesting that customizability is an advantageous component of the control system. Replacing buttons from a traditional handheld controller with sEMG did not substantively reduce performance. The system provided adequate control to all participants to complete functional tasks in virtual reality such as opening door handles, turning stove dials, eating, and drinking, all of which enable independence and improved quality of life for these individuals.

Defining breast cancer-related lymphedema (BCRL) prevalence and risk factors: A pragmatic approach to lymphedema surveillance.

Introduction: We presented the key findings from Singapore's Changi General Hospital Breast Centre's lymphedema surveillance strategy that used patients' reported symptoms, standard arm circumference measurements and clinical assessment in the diagnosis of breast cancer-related lymphedema (BCRL). Our secondary aim was to highlight and discuss important elements of a surveillance strategy that can be implemented to track this outcome measure of breast cancer treatment for future research. Method: We conducted a cross-sectional study of 511 breast cancer patients to assess the prevalence of BCRL and its associated risk factors. We defined BCRL prevalence rates based on patients' self-reporting, objective arm circumference measure-ments and clinical diagnosis based on International Society of Lymphology (ISL) staging. Results: The median follow-up of patients was 88.8 months. The cumulative prevalence rate in the cohort was 30.9%. The cohort of BCRL patients were older (58.4 versus [vs] 54.9 years), had higher mean Body Mass Index (27.7 vs 25.2), higher proportion of mastectomy (77% vs 64.3%), axillary clearance, less likely breast reconstruction, higher-grade tumour, more lymph nodes excised, more advanced nodal disease, and had undergone adjuvant chemotherapy. However, clinically apparent BCRL was only 6.5% (33 out of 511 patients). The proportion of clinically significant BCRL in patients undergoing sentinel lymph node biopsy (SLNB) or axillary sampling was 1.7% compared to 9.9% in patients who had undergone axillary clearance. Majority of the BCRL were subclinical or mild in severity. Conclusion: Our study showed that our rates of BCRL were comparable to international rates and highlighted similar patient profiles who were at risk of developing the disease. Having a comprehensive lymphedema surveillance strategy is paramount in paving the way for future studies.

The role of breast cancer-related arm lymphedema in physical functioning and physical activity participation among long-term African American breast cancer survivors.

PURPOSE: Breast cancer-related arm lymphedema (BCRL) is a common chronic and debilitating condition that involves accumulation of lymphatic fluid in the arm or hand. Limited data are available on BCRL in African American women. Lack of physical activity (PA) and poor physical functioning (PF) are both associated with increased morbidity and mortality among breast cancer survivors. We examined the association of BCRL with PA and PF among African American breast cancer survivors. METHODS: 323 African American women who previously participated in a case-only study in three states (TN, GA, SC) completed a survivorship-focused questionnaire (mean: 4.2 years post-diagnosis) in 2015-2016. Validated measures were used to determine BCRL, PF, and PA. Adjusted binary logistic regression models estimated ORs and 95% CIs for the association of BCRL and meeting PA guidelines (≥ 150 min/week), while multinomial logistic regression was used for PF and PA (minutes/week) categorized based on tertiles. RESULTS: Approximately 32% reported BCRL since diagnosis; 25.4% reported BCRL in the last 12-months. About 26% and 50% reported that BCRL interfered with exercise and ability to do daily activities, respectively. The mean PF among those with BCRL was 51.0(SD:29.0) vs. 68.5(SD:30.1) among those without BCRL. BCRL was associated with lower PF (adjusted-OR for tertile 2: 2.12(95% CI:1.03-4.36) and adjusted-OR for tertile 1: 2.93(95% CI:1.44-5.96)). CONCLUSIONS: BCRL was associated with lower PF among long-term African American breast cancer survivors. Continued monitoring by health care professionals and increased education and behavioral interventions to support PA and improved PF among survivors living with BCRL are warranted.

Trajectory of mid-arm subcutaneous fat, muscle mass predicts mortality in hemodialysis patients independent of body mass index.

Although decreasing body mass index (BMI) is associated with higher mortality risk in patients undergoing hemodialysis (HD), BMI neither differentiates muscle and fat mass nor provides information about the variations of fat distribution. It remains unclear whether changes over time in fat and muscle mass are associated with mortality. We examined the prognostic significance of trajectory in the triceps skinfold (TSF) thickness and mid-upper arm circumference (MUAC). In this multicenter prospective cohort study, 972 outpatients (mean age, 54.5 years; 55.3% men) undergoing maintenance HD at 22 treatment centers were included. We calculated the relative change in TSF and MUAC over a 1-year period. The outcome was all-cause mortality. Kaplan-Meier, Cox proportional hazard analyses, restricted cubic splines, and Fine and Gray sub-distribution hazards models were performed to examine whether TSF and MUAC trajectories were associated with all-cause mortality. During follow-up (median, 48.0 months), 206 (21.2%) HD patients died. Compared with the lowest trajectory group, the highest trajectories of TSF and MUAC were independently associated with lower risk for all-cause mortality (HR = 0.405, 95% CI 0.257-0.640; HR = 0.537; 95% CI 0.345-0.837; respectively), even adjusting for BMI trajectory. Increasing TSF and MUAC over time, measured as continuous variables and expressed per 1-standard deviation decrease, were associated with a 55.7% (HR = 0.443, 95% CI 0.302-0.649), and 97.8% (HR = 0.022, 95% CI 0.005-0.102) decreased risk of all-cause mortality. Reduction of TSF and MUAC are independently associated with lower all-cause mortality, independent of change in BMI. Our study revealed that the trajectory of TSF thickness and MUAC provides additional prognostic information to the BMI trajectory in HD patients.

Bimanual coordination and spinal cord neuromodulation: how neural substrates of bimanual movements are altered by transcutaneous spinal cord stimulation.

Humans use their arms in complex ways that often demand two-handed coordination. Neurological conditions limit this impressive feature of the human motor system. Understanding how neuromodulatory techniques may alter neural mechanisms of bimanual coordination is a vital step towards designing efficient rehabilitation interventions. By non-invasively activating the spinal cord, transcutaneous spinal cord stimulation (tSCS) promotes recovery of motor function after spinal cord injury. A multitude of research studies have attempted to capture the underlying neural mechanisms of these effects using a variety of electrophysiological tools, but the influence of tSCS on cortical rhythms recorded via electroencephalography remains poorly understood, especially during bimanual actions. We recruited 12 neurologically intact participants to investigate the effect of cervical tSCS on sensorimotor cortical oscillations. We examined changes in the movement kinematics during the application of tSCS as well as the cortical activation level and interhemispheric connectivity during the execution of unimanual and bimanual arm reaching movements that represent activities of daily life. Behavioral assessment of the movements showed improvement of movement time and error during a bimanual common-goal movement when tSCS was delivered, but no difference was found in the performance of unimanual and bimanual dual-goal movements with the application of tSCS. In the alpha band, spectral power was modulated with tSCS in the direction of synchronization in the primary motor cortex during unimanual and bimanual dual-goal movements and in the somatosensory cortex during unimanual movements. In the beta band, tSCS significantly increased spectral power in the primary motor and somatosensory cortices during the performance of bimanual common-goal and unimanual movements. A significant increase in interhemispheric connectivity in the primary motor cortex in the alpha band was only observed during unimanual tasks in the presence of tSCS. Our observations provide, for the first time, information regarding the supra-spinal effects of tSCS as a neuromodulatory technique applied to the spinal cord during the execution of bi- and unimanual arm movements. They also corroborate the suppressive effect of tSCS at the cortical level reported in previous studies. These findings may guide the design of improved rehabilitation interventions using tSCS for the recovery of upper-limb function in the future.

Neuromechanical Differences between Pronated and Supinated Forearm Positions during Upper-Body Wingate Tests.

Arm-cycling is a versatile exercise modality with applications in both athletic enhancement and rehabilitation, yet the influence of forearm orientation remains understudied. Thus, this study aimed to investigate the impact of forearm position on upper-body arm-cycling Wingate tests. Fourteen adult males (27.3 ± 5.8 years) underwent bilateral assessments of handgrip strength in standing and seated positions, followed by pronated and supinated forward arm-cycling Wingate tests. Electromyography (EMG) was recorded from five upper-extremity muscles, including anterior deltoid, triceps brachii lateral head, biceps brachii, latissimus dorsi, and brachioradialis. Simultaneously, bilateral normal and propulsion forces were measured at the pedal-crank interface. Rate of perceived exertion (RPE), power output, and fatigue index were recorded post-test. The results showed that a pronated forearm position provided significantly (p < 0.05) higher normal and propulsion forces and triceps brachii muscle activation patterns during arm-cycling. No significant difference in RPE was observed between forearm positions (p = 0.17). A positive correlation was found between seated handgrip strength and peak power output during the Wingate test while pronated (dominant: p = 0.01, r = 0.55; non-dominant: p = 0.03, r = 0.49) and supinated (dominant: p = 0.03, r = 0.51; don-dominant: p = 0.04, r = 0.47). Fatigue changed the force and EMG profile during the Wingate test. In conclusion, this study enhances our understanding of forearm position's impact on upper-body Wingate tests. These findings have implications for optimizing training and performance strategies in individuals using arm-cycling for athletic enhancement and rehabilitation.

Evaluation of a passive arm-support exoskeleton for surgical team members: Results from live surgeries.

BACKGROUND: Musculoskeletal symptoms and injuries adversely impact the health of surgical team members and their performance in the operating room (OR). Though ergonomic risks in surgery are well-recognized, mitigating these risks is especially difficult. In this study, we aimed to assess the impacts of an exoskeleton when used by OR team members during live surgeries. METHODS: A commercial passive arm-support exoskeleton was used. One surgical nurse, one attending surgeon, and five surgical trainees participated. Twenty-seven surgeries were completed, 12 with and 15 without the exoskeleton. Upper-body postures and muscle activation levels were measured during the surgeries using inertial measurement units and electromyography sensors, respectively. Postures, muscle activation levels, and self-report metrics were compared between the baseline and exoskeleton conditions using non-parametric tests. RESULTS: Using the exoskeleton significantly decreased the percentage of time in demanding postures (>45° shoulder elevation) for the right shoulder by 7% and decreased peak muscle activation of the left trapezius, right deltoid, and right lumbar erector spinae muscles, by 7%, 8%, and 12%, respectively. No differences were found in perceived effort, and overall scores on usability ranged from "OK" to "excellent." CONCLUSIONS: Arm-support exoskeletons have the potential to assist OR team members in reducing musculoskeletal pain and fatigue indicators. To further increase usability in the OR, however, better methods are needed to identify the surgical tasks for which an exoskeleton is effective.