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Surface-electromyography (sEMG) allows investigators to detect differences in muscle activation due to hand pathologies. However, its use as a functional indicator and the challenges related to the required normalization have not been fully addressed. This study aimed to use forearm muscle sEMG signals to distinguish between healthy individuals and patients with hand osteoarthritis (HOA). sEMG data were collected from seven sensors on the forearms of twenty-one healthy women and twenty women with HOA during the Sollerman test. Amplitude-based parameters (median and range) were normalized using three methods: maximum signals during Sollerman tasks (MAX), during maximum voluntary contraction tasks (MVC), and during maximum effort grasping (GRASP). Waveform parameters (new-zero-crossing and enhanced-wavelength) were also considered. MVC and GRASP resulted in higher values in patients. Discriminant analysis showed the worst success rates in predicting HOA for amplitude-based parameters, requiring extra tasks for normalization (MVC or GRASP), while when using both amplitude (MAX) and waveform parameters and only Sollerman tasks, the success rate reached 90.2% Results show the importance of normalization methods, highlight the potential of waveform parameters as reliable pathology indicators, and suggest sEMG as a diagnostic tool. Additionally, the comparison of sEMG parameters allows the functional impact of suffering from HOA to be inferred.

The aim of this cross-sectional field study was to establish the condition of hand and forearm skin barrier among dentists and physicians and how it may be associated with personal and work-related factors. The study consisted of an occupational questionnaire, clinical examination of skin on hands, and transepidermal water loss (TEWL) and pH measurements on hands and forearms. The participants were divided in the following groups (N=37 each, N=148 in total): physicians, medical surgeons, dentists, and dental surgeons. We calculated the difference between hand and forearm TEWL and pH (ΔTEWL and ΔpH, respectively) and divided it by the forearm values (ΔTEWL% and ΔpH%, respectively). There was a clear trend of increasing median ΔTEWL%, starting from physicians with non-surgical specialisation (56 %) to medical surgeons (65 %), dentists (104 %), and dental surgeons (108 %), with the latter two groups showing particularly worrisome signs of work-related skin barrier impairment, since they had double the TEWL on hands than on forearms. Although less prominent, the same worsening trend was noted for skin pH, with dental surgeons having on average a 0.3 points higher skin pH on hands than on forearms. These findings were mainly associated with prolonged glove use and male sex. Our findings also suggest that comparing TEWL and pH between hands and forearms can better establish occupational skin barrier impairment on hands., (© 2024 Željka Babić et al., published by Sciendo.)

Objectives: This study explores the feasibility and effects of low-intensity blood flow restriction exercise on forearm muscle strength and function in individuals with spinal cord injury., Study Design: Pilot randomized clinical trial., Patients and Methods: Ten male and female adult participants with chronic cervical and thoracic spinal cord injury underwent an 8-week low-intensity blood flow restriction exercise programme that targeted forearm muscles. Each participant's contralateral forearm served as the control. Grip strength was the primary outcome measure, and participants also provided qualitative feedback on their experiences., Results: The study revealed a significant increase in participants' forearm muscle strength on the experimental side engaged in low-intensity blood flow restriction training, with an average strength gain of 7.5 ± 0.36 kg after 16 exercise sessions (Cohen's d = -6.32, 95% CI -8.34, -6.68). In comparison, the control side, following a conventional high- intensity exercise regimen without BFR, showed a more modest strength increase of 4.4 ± 0.67 kg. A mean Patient's Global Impression of Change score of 2.2 reflected overall improvements in participants' daily activities and health status., Conclusion: This study highlights the feasibility and effectiveness of low-intensity blood flow restriction exercise as a safe and promising approach to enhancing forearm muscle strength in individuals with spinal cord injury. The observed positive outcomes, coupled with a high level of participant satisfaction, underscore the potential of this innovative method to significantly improve limb muscle strength, thereby contributing to greater functional independence in this population.

This study aimed to investigate deformity patterns that cause clinical impairments and determine the acceptable range of deformity in the treatment of forearm diaphyseal fractures. A three-dimensional (3D) deformity analysis based on computed bone models was performed on 39 patients with malunited diaphyseal both-bone forearm fractures to investigate the 3D deformity patterns of the radius and ulna at the fracture location and the relationship between 3D deformity and clinical impairments. Clinical impairments were evaluated using forearm motion deficit. Cutoff values of forearm deformities were calculated by performing receiver operating characteristic analysis using the deformity angle and the limited forearm rotation range of motion (less than 50° of pronation or supination) resulting in activities of daily living (ADL) impairment as variables. The extension, varus, and pronation deformities most commonly occurred in the radius, whereas the extension deformity was commonly observed in the ulna. A positive correlation was observed between pronation deficit and extension deformity of the radius (R = 0.41) and between supination deficit and pronation deformity of the ulna (R = 0.44). In contrast, a negative correlation was observed between pronation deficit and pronation deformity of the radius (R = -0.44) and between pronation deficit and pronation deformity of the ulna (R = -0.51). To minimize ADL impairment, radial extension deformity should be <18.4°, radial rotation deformity <12.8°, and ulnar rotation deformity <16.6°. The deformities in the sagittal and axial planes of the radius and in the axial plane of the ulna were responsible for the limited forearm rotation., (© 2024 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals LLC on behalf of Orthopaedic Research Society.)

Introduction: Pain sensitivity is the main finding of central sensitization (CS) and can occur in patients with chronic shoulder pain. However, there is limited evidence concerning the distribution of pain sensitivity in shoulders, forearms, and legs in patients with CS associated with chronic shoulder pain. The present study aimed to determine the distribution of pain sensitivity in patients with CS associated with chronic subacromial pain syndrome (SPS)., Method: This cross-sectional study included 58 patients with chronic SPS and CS (patient group) and 58 healthy participants (control group). The presence of CS was determined using the Central Sensitization Inventory (CSI). To determine the distribution of pain sensitivity, pressure pain threshold (PPT) measurements were performed from the shoulders, forearms, and legs., Results: There was no significant difference between the two groups in terms of sociodemographic data (p > 0.05). The patient group had a significantly higher CSI score (p < 0.001) and lower PPTs in all regions (p < 0.05) than the control group. Unlike the control group, the patient group had lower PPTs on the affected side for the shoulder [mean difference (MD) 95% confidence interval (CI): 1.2 (-1.7 to -0.6)], forearm [MD 95% CI: 1.1 (-1.7 to -0.6)], and leg [MD 95% CI: 0.9 (-1.4 to -0.3)] compared with the contralateral side (p < 0.001)., Conclusion: Pain sensitivity is more pronounced in the affected shoulder and the forearm and leg located on this side than in those on the contralateral side in patients with CS associated with chronic SPS., Competing Interests: Declaration of Competing interest The authors have no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Lumbrical muscles originate on the flexor digitorum profundus (FDP) tendons and, during fist making, they move in the same direction when FDP muscle produces maximal proximal tendon gliding. Injuries of the bipennate lumbricals have been described when a shear force acts between the origins on adjacent tendons of the FDP, as they glide in opposite directions in asymmetric hand postures. Other structures of the deep flexors complex can be affected during this injury mechanism, due to the so-called quadriga effect, which can commonly occur during sport climbing practise. Biomechanical studies are needed to better understand the pathomechanism. A cadaveric study was designed to analyse the effects of load during the fourth lumbrical muscle injury mechanism. The amount of FDP tendon gliding and metacarpophalangeal (MCP) joint flexion of the 5th finger were calculated. Ten fresh-frozen cadaveric specimens (ten non-paired forearms and hands) were used. The specimens were placed on a custom-made loading apparatus. The FDP of the 5th finger was loaded, inducing isolated flexion of the 5th finger, until rupture. The rupture occurred in all specimens, under a load of 11 kg (SD 4.94), at 9.23 mm of proximal tendon gliding (SD 3.55) and at 21.4° (SD 28.91) of MCP joint flexion. Lumbrical muscle detachment from the 4th FDP was observed, from distal to proximal, and changes in FDP tendons at the distal forearm level too. The quadriga effect can lead to injury of the bipennate lumbrical muscles and the deep flexors complex in the hand and forearm., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Bone mineral density measured at the ultra-distal forearm site was associated with any fracture, as well as distal radius fracture in women from a longitudinal cohort study., Purpose: Femoral neck (BMD hip ) and lumbar spine (BMD spine ) bone mineral density (BMD) are routinely used to assess fracture risk. More data are needed to understand how ultra-distal forearm BMD (BMD UDforearm ) may assist fracture prediction., Methods: Using a Lunar DPX-L, Geelong Osteoporosis Study women (n = 1026), aged 40-90 years, had BMD measured. Incident low-trauma fractures were radiologically verified. Using Cox proportional hazard models, hazard ratios (HR) were calculated for BMD UDforearm as a continuous variable (expressed as a one-unit decrease in T-score) and a categorical variable (normal/osteopenia/osteoporosis). Areas under receiver operating characteristics (AUROC) curves were calculated. Analyses were conducted for any fracture and distal radius fractures., Results: During 14,270 person-years of follow-up, there were 318 fractures (85 distal radius). In adjusted models, continuous BMD UDforearm was associated with any (HR 1.26;95%CI 1.15-1.39) and distal radius fractures (HR 1.59;95%CI 1.38-1.83). AUROCs for continuous BMD UDforearm , 33% forearm(BMD 33%forearm ), BMD hip , BMD spine , and FRAX without BMD were similar for any fracture (p > 0.05). For distal radius fracture, the AUROC for BMD UDforearm was higher than other sites and FRAX (p < 0.05). In adjusted models, those with osteoporosis had a higher likelihood of any fracture (HR 2.12; 95%CI 1.50-2.98). For distal radius fractures, both osteopenia and osteoporosis had a higher risk (HR 4.31; 95%CI 2.59-7.15 and 4.81; 95%CI 2.70-8.58). AUROCs for any fracture were similar for categorical BMD at all sites but lower for FRAX (p < 0.05). For distal radius fractures, the AUROC for BMD UDforearm , was higher than other sites and FRAX (p < 0.05)., Conclusion: Ultra-distal forearm BMD may aid risk assessments for any distal radius fractures., (© 2024. The Author(s).)

Background: The shortened version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) and Patient Rated Wrist/Hand Evaluation (PRWHE) are commonly used questionnaires to assess patient-reported hand function. Information about the measurement properties of the Dutch versions is scarce., Objective: To gain insight into the measurement properties of the Dutch language versions of the QuickDASH and the PRWHE in patients with (non)specific complaints of the hand, wrist, forearm and elbow., Methods: Internal consistency, construct validity, test-retest reliability, responsiveness, and floor and ceiling effects were assessed according to COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) recommendations., Results: Questionnaires were filled out by 132 patients. Internal consistency of QuickDASH (Cronbach's α= 0.92) and PRWHE (Cronbach's α= 0.97) was high. Predefined hypotheses for construct validity were not confirmed for 75% for both QuickDASH and PRWHE (accordance with 62% of predefined hypotheses for both questionnaires). Test-retest reliability of QuickDASH (ICC = 0.90) and PRWHE (ICC = 0.87) was good. Both QuickDASH (AUC = 0.84) and PRWHE (AUC = 0.80) showed good responsiveness. No floor or ceiling effects were present., Conclusions: Measurement properties of the Dutch language versions of the QuickDASH and the PRWHE, applied to patients with (non)specific complaints of the hand, wrist, forearm and elbow, were very similar. Test-retest reliability and responsiveness were good for both QuickDASH and PRWHE. Construct validity could not be demonstrated sufficiently.

Each year 65% of young athletes and 25% of physically active adults suffer from at least one musculoskeletal injury that prevents them from continuing with physical activity, negatively influencing their physical and mental well-being. The treatment of musculoskeletal injuries with the adhesive elastic kinesiology tape (KT) decreases the recovery time. Patients can thus recommence physical exercise earlier. Here, a novel KT based on auxetic structures is proposed to simplify the application procedure and allow personalization. This novel KT exploits the form-fitting property of auxetics as well as their ability to simultaneously expand in two perpendicular directions when stretched. The auxetic contribution is tuned by optimizing the structure design using analytical equations and experimental measurements. A reentrant honeycomb topology is selected to demonstrate the validity of the proposed approach. Prototypes of auxetic KT to treat general elbow pains and muscle tenseness in the forearm are developed., (© 2022. The Author(s).)

This study aimed to compare the contact area, mean pressure, and peak pressure of the radiocapitellar joint (RCJ) in the upper limb after transradial amputation with those of the normal upper limb during elbow flexion and forearm rotation. Testing was performed using ten fresh-frozen upper limbs, and the transradial amputation was performed 5 cm proximal to the radial styloid process. The specimens were connected to a custom-designed apparatus for testing. A pressure sensor was inserted into the RCJ. The biomechanical indices of the RCJ were measured during elbow flexion and forearm rotation in all specimens. There was no significant difference in the contact area between the normal and transradial amputated upper limbs. However, in the upper limbs after transradial amputation, the mean pressure was higher than that in the normal upper limbs at all positions of elbow flexion and forearm rotation. The peak pressure was significantly higher in the upper limbs after transradial amputation than in the normal upper limbs, and was especially increased during pronation at 45° of elbow flexion. In conclusion, these results could cause cartilage erosion in the RCJ of transradial amputees. Thus, methods to reduce the pressure of the RCJ should be considered when a myoelectric prosthesis is developed.

The Comparison: A Elbow and forearm with erythematous, well-demarcated, pink plaques with mild micaceous scale in a 42-year-old White woman. B Elbow and forearm with violaceous, well-demarcated plaques with micaceous scale and hyperpigmented patches around the active plaques in a 58-year-old Black man.

Introduction: The transition from pediatric to adolescent fractures can lead to uncertainty on what level of surgical correction is warranted as remodeling is limited in these older patients., Discussion: Adolescent diaphyseal radial shaft fractures present several unique challenges; the radial bow must be restored to preserve forearm rotation and there are several clinical scenarios where plating, even in the skeletally immature child, is strongly recommended and will have more reliable results over flexible intramedullary nails. In addition, judging how much angulation, rotation, and displacement will remodel in the older child can be a challenging decision, even for experienced pediatric orthopaedists., Conclusion: This overview discusses parameters for acceptable alignment in these fractures, when surgical fixation should be considered, and circumstances where plating should be considered over flexible nails., Competing Interests: The author declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: While management recommendations for distal radius fractures in both young and skeletally mature patients have been generally well-established, controversy still exists regarding optimal management in adolescent patients approaching skeletal maturity. Thus, the goal of this review is to analyze relevant literature and provide expert recommendations regarding the management of distal radius fractures in this patient population., Methods: A PubMed search was performed to identify literature pertaining to distal radius fractures in adolescent patients, defined as 11 to 14 years in girls and 13 to 15 years in boys. Relevant articles were selected and summarized., Results: Distal radius fractures demonstrate significant potential for remodeling of angular deformity and bayonet apposition, even in patients older than 12 years of age. Rotational forearm range of motion and functional outcomes are acceptable with up to 15 degrees of residual angulation. Closed reduction and percutaneous pinning reduces fracture redisplacement but has a high associated complication rate. There is no literature comparing plate versus pin fixation of distal radius fractures in the pediatric population, but in adults plate fixation is associated with higher cost with no improvement in long-term functional outcomes., Conclusions: Remodeling can still be expected to occur in adolescent patients, and even with residual deformity functional outcomes after distal radius fractures are excellent. Up to 15 degrees of residual angulation can be accepted before considering operative management. Smooth pins should be considered over plates as first-line operative management for unstable fractures that fail nonoperative treatment., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose : To investigate the impact of shoulder subluxation (SS) on peripheral nerve conduction and function of the hemiplegic upper extremity (HUE) in poststroke patients. Methods : Thirty post-stroke patients were selected (SS group: 15 patients, non-SS group: 15 patients, respectively). Evaluation of nerve conduction in upper limbs: the compound muscle action potential (CMAP) amplitude and latency of suprascapular, axillary, musculocutaneous, radial, median, and ulnar nerves; the motor and sensory conduction velocity and the sensory nerve action potential (SNAP) amplitude of median, ulnar, and radial nerves. The Brunnstrom stage scale was used to evaluate the HUE motor function. Results : Compared with the healthy side, the CMAP and SNAP amplitudes of tested nerves on the HUE in both groups were lower, and the CMAP latency of the suprascapular, axillary and musculocutaneous nerves on the HUE in the SS group was longer (P < 0.05). Compared with the HUE in non-SS group, the CMAP amplitude of tested nerves (except ulnar) was decreased more (P < 0.05), the motor conduction velocity of the median nerve was lower (P < 0.05), and the Brunnstrom stage of the HUE was lower in SS group (P < 0.05). Conclusions : Stroke may lead to extensive abnormal nerve conduction on the HUE, and SS may aggravate the abnormality, which may disturb the recovery of upper limb function.

Competing Interests: Declaration of interests I declare no competing interests.

Background: An increase in blood flow in the forearm arteries has been reported after brachial plexus block (BPB). However, few studies have quantitatively analysed the blood flow of the forearm arteries after BPB or have studied only partial haemodynamic parameters. The purpose of the present study was to comprehensively assess blood flow changes in the distal radial artery (RA) and ulnar artery (UA) after BPB performed via a new costoclavicular space (CCS) approach using colour Doppler ultrasound., Methods: Thirty patients who underwent amputated finger replantation and received ultrasound-guided costoclavicular BPB were included in the study. The haemodynamic parameters of the RA and UA were recorded before the block and 10 min, 20 min, and 30 min after the block using colour Doppler ultrasound to determine the peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (V mean ), pulsatility index (PI), resistance index (RI) and area. The volumetric flow rate (VFR) was calculated using the formula Q = area×V mean . The aforementioned parameters were compared not only before and after the BPB but also between the RA and UA., Results: Compared with those of the respective baselines, there was a significant increase in the PSV, EDV, V mean , area, and VFR and a significant decrease in the PI and RI of the RA and UA 10 min, 20 min, and 30 min post-block. The increase 30 min post-block in EDV (258.68 % in the RA, 279.63 % in the UA) was the most notable, followed by that in the V mean (183.36 % in the RA, 235.24 % in the UA), and the PSV (139.11 % in the RA, 153.15 % in the UA) changed minimally. The V mean and VFR of the RA were significantly greater than those of the UA before the BPB; however, there was no significant difference in the VFR between the RA and UA after the BPB., Conclusions: A costoclavicular BPB can increase blood flow in the forearm arteries. The RA had a higher volumetric flow rate than the UA before the BPB; however, the potential blood supply capacity of the UA was similar to that of the RA after a BPB., Trial Registration: This study was registered at the Chinese Clinical Trial Registry (http://www.chictr.org.cn/searchproj.aspx, clinical trial number: ChiCTR 1900023796, date of registration: June 12, 2019).

Background: Bone parameters derived from HR-pQCT have been investigated on a parameter-by-parameter basis for different clinical conditions. However, little is known regarding the interrelationships of bone parameters and the spatial distribution of these interrelationships. In this work: 1) we investigate compartmental interrelationships of bone parameters; 2) assess the spatial distribution of interrelationships of bone parameters; and 3) compare interrelationships of bone parameters between postmenopausal women with and without a recent Colles' fracture., Methods: Images from the unaffected radius in fracture cases (n=84), and from the non-dominant radius of controls (n=98) were obtained using HR-pQCT. Trabecular voxel-based maps of local bone volume fraction (L.Tb.BV/TV), homogenized volumetric bone mineral density (H.Tb.BMD), homogenized μFEA-derived strain energy density (H.Tb.SED), and homogenized inter-trabecular distances (H.Tb.1/N) were generated; as well as surface-based maps of apparent cortical bone thickness (Surf.app.Ct.Th), porosity-weighted cortical bone thickness (Surf.Ct.SIT), mean cortical BMD (Surf.Ct.BMD), and mean cortical SED (Surf.Ct.SED). Anatomical correspondences across the parametric maps in the study were established via spatial normalization to a common template. Mean values of the parametric maps before spatial normalization were used to assess compartmental Spearman's rank partial correlations of bone parameters (e.g., between H.Tb.BMD and L.Tb.BV/TV or between Surf.Ct.BMD and Surf.app.Ct.Th). Spearman's rank partial correlations were also assessed for each voxel and vertex of the spatially normalized parametric maps, thus generating maps of Spearman's rank partial correlation coefficients. Correlations were performed independently within each group, and compared between groups using the Fisher's Z transformation., Results: All within-group global trabecular and cortical Spearman's rank partial correlations were significant; and the correlations of H.Tb.BMD-L.Tb.BV/TV, H.Tb.BMD-H.Tb.1/N, L.Tb.BV/TV-H.Tb.1/N, Surf.Ct.BMD-Surf.Ct.SED and Surf.Ct.SIT-Surf.Ct.SED were significantly different between controls and fracture cases. The spatial analyses revealed significant heterogeneous voxel- and surface-based correlation coefficient maps across the distal radius for both groups; and the correlation maps of H.Tb.BMD-L.Tb.BV/TV, H.Tb.BMD-H.Tb.1/N, L.Tb.BV/TV-H.Tb.1/N, H.Tb.1/N-H.Tb.SED and Surf.app.Ct.Th - Surf.Ct.SIT yielded small clusters of significant correlation differences between groups., Discussion: The heterogeneous spatial distribution of interrelationships of bone parameters assessing density, microstructure, geometry and biomechanics, along with their global and local differences between controls and fracture cases, may help us further understand different bone mechanisms of bone fracture., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Shiraishi, Burghardt, Osaki, Khosla and Carballido-Gamio.)

[Aim] Because painful skin tears frequently occur in older patients, the prevention of skin tears is fundamental to improve their quality of life. However, a risk assessment tool for skin tears has not been established yet in Japan. Therefore, we aimed to propose a risk scoring tool for skin tears in Japanese older adult. [Methods] We conducted a prospective cohort study with 6-month follow-up in two long-term care hospitals in Japan. A total of 257 inpatients were recruited. Patient and skin characteristics were collected at baseline, and the occurrence of forearm skin tears were examined during follow-up. To develop a risk scoring tool, we identified risk factors, and converted their coefficients estimated in the multiple logistic regression analysis into simplified scores. The predictive accuracy of the total score was evaluated. [Results] Of 244 participants, 29 developed forearm skin tears during the follow-up period, a cumulative incidence of 13.5%. Senile purpura, pseudoscar, contracture, and dry skin were identified as risk factors for skin tears. Their weighted scores were 6, 4, 5, and 6, respectively. The area under the receiver operating characteristic curve of the total score was 0.806. At a cut-off score of 12, the sensitivity was 0.86, and the specificity was 0.67. [Conclusion] Our forearm skin tear risk scoring tool showed high accuracy, whereas specificity was low. This tool can contribute to prevent forearm skin tears in Japanese older adults., (Copyright © 2021 Tissue Viability Society. Published by Elsevier Ltd. All rights reserved.)

Introduction: Even after reconstructive surgery, it is still difficult for patients with severe burns to achieve independent eating activity. In this project, we customized the forearm pronation's assistant tableware to assist in improvement with eating activities., Methods: From January 2017 to December 2018, 28 patients with severe burns including the hands were recruited. For the patient's independent eating activities, we customized forearm pronation's tableware (forks and spoons). We compared modified Barthel index (MBI) and Visual analogue scale (VAS) of satisfaction under three conditions: no auxiliary tableware, ADL universal cuff, or forearm pronation tableware; to compare the duration and the weight of food spilled during lunch when the patients wore the ADL universal cuff or the forearm pronation's tableware. Differences in MBI (rank data) were tested by the Friedman test, differences in VAS (normal distribution) were tested with One-way ANOVA (Bonferroni), differences in the duration and the weight (normal distribution data) were tested by paired sample t test., Results: After wearing the forearm pronation's assistant tableware, MBI VAS both increased more than when the patients did not wear the auxiliary tableware (all p＜0.05). When the subjects wore forearm pronation tableware, the duration of lunch significantly decreased and the quality of eating activity significantly improved compared to the ADL universal cuff in eating activity (all p＜0.05)., Conclusion: After wearing the forearm pronation's assistant tableware, the patients with severe burns completely or almost completely accomplished independent eating, the duration was decreased, and during eating activity the quality and the satisfaction were improved., Clinical Trial Registration: Chinese Clinical trial registry, ChiCTR1800019963., (Copyright © 2020 Elsevier Ltd and ISBI. All rights reserved.)

Purpose: The flexor carpi radialis brevis (FCRB) is a supernumerary musculotendinous structure of the wrist that has been the focus of some interest in the last decade. While its anatomy is well known, its in vivo function remains unknown as it has never been studied., Methods: Eleven cases of FCRB underwent a multimodal ultrasound consisting of B-mode, color Doppler and shear wave elastography., Results: A pennate shape was observed in all cases and the mean value of the cross-sectional area was 0.8 cm 2 (SD 0.3 cm 2 ). Young's modulus was significantly (p < 0.01) different between the resting position and active flexion or passive extension., Conclusion: Our study demonstrates that the FCRB shows biomechanics of a typical skeletal muscle and is voluntarily controlled by flexing the wrist. Absent in other vertebrate taxa, the FCRB probably plays a role in active stability of the wrist in Human.

Current literature suggests that greater than 50% of survivors of a stroke cannot accurately perceive where their upper extremity is positioned. Our recent work demonstrates that the extent to which this perception is affected can depend on how the task is performed. For example, individuals with stroke who have a deficit in mirroring the position of their passively-placed paretic forearm during a between-arms task may accurately reproduce the position of their actively-controlled paretic forearm during a single-arm task. Moreover, the ability of individuals with various types of unilateral lesions to locate their thumb can depend on whether they reach for their paretic thumb or non-paretic thumb. Consequently, we investigated to what extent the accuracy of individuals post-hemiparetic stroke in mirroring forearm positions on a between-arms task is influenced by various conditions. Eighteen participants with hemiparetic stroke rotated their reference forearm to a target position, and then rotated their opposite forearm to concurrently mirror the position of their reference forearm. This task was performed when participants referenced each forearm (paretic, non-paretic) at two target positions (extension, flexion) for two modes of limb control (passive, active). We quantified for every testing scenario of each participant their position-mirroring error. The number of times for which participants were classified as having a deficit was least when mirroring forearm positions at the flexed position when referencing their non-paretic forearm. Additionally, the difference in the magnitude of errors when participants referenced each arm was greater during active than passive movements. Findings from this study provide further evidence that the accuracy with which individuals post stroke perceive the position of their limbs can depend on how a task is performed. Factors to consider include whether movements are active versus passive, which limb is referenced, and where the limb is positioned., Competing Interests: The authors have declared that no competing interests exist.

The posterior interosseous nerve (PIN) is the terminal branch of the radial nerve. The symptoms of PIN palsy vary markedly according to its types. In this report, we present the case of a 61-years-old male patient with an unusual manifestation of non-traumatic novel type of PIN palsy. A complicated course was involved in the diagnosis of this disease. The operation was performed after verification of PIN palsy. Recovery of symptoms was observed in a follow-up conducted three years later. Additionally, the electromyography examination returned to normal.

Background: McArdle sign is a phenomenon of impaired gait and muscle weakness that occurs with neck flexion, immediately reversible with neck extension. A recent report measured the specificity of this sign for multiple sclerosis by measuring differences in peak torque of the extensor digitorum between neck extension and flexion., Methods: This substudy included 73 participants (29 multiple sclerosis, 20 non-multiple sclerosis myelopathies, 5 peripheral nerve disorders, and 19 healthy controls). The effect of neck position was assessed on muscle stiffness and neuromechanical error of the extensor digitorum., Findings: Patients with multiple sclerosis had greater neuromechanical error (sum of squared error of prediction) compared to controls (P = 0.023) and non-multiple sclerosis myelopathies (P = 0.003). Neuromechanical error also provided improved sensitivity/specificity of McArdle sign. Peak torque, muscle stiffness, and neuromechanical error could distinguish multiple sclerosis from other myelopathies with 80% specificity and 97% sensitivity (AUC = 0.95)., Interpretation: A decrease in muscle stiffness and neuromechanical error in neck flexion compared to extension are additional indicators for a diagnosis of multiple sclerosis. Analysis of muscle stiffness may provide insights into the pathophysiology of this specific clinical sign for multiple sclerosis. Furthermore, muscle stiffness may provide an additional accurate, simple assessment to evaluate multiple sclerosis therapeutic interventions and disease progression., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The mechanical muscular oscillations are rarely the objective of investigations regarding the identification of a biomarker for Parkinson's disease (PD). Therefore, the aim of this study was to investigate whether or not this specific motor output differs between PD patients and controls. The novelty is that patients without tremor are investigated performing a unilateral isometric motor task. The force of armflexors and the forearm acceleration (ACC) were recorded as well as the mechanomyography of the biceps brachii (MMGbi), brachioradialis (MMGbra) and pectoralis major (MMGpect) muscles using a piezoelectric-sensor-based system during a unilateral motor task at 70% of the MVIC. The frequency, a power-frequency-ratio, the amplitude variation, the slope of amplitudes and their interlimb asymmetries were analysed. The results indicate that the oscillatory behavior of muscular output in PD without tremor deviates from controls in some parameters: Significant differences appeared for the power-frequency-ratio (p = 0.001, r = 0.43) and for the amplitude variation (p = 0.003, r = 0.34) of MMGpect. The interlimb asymmetries differed significantly concerning the power-frequency-ratio of MMGbi (p = 0.013, r = 0.42) and MMGbra (p = 0.048, r = 0.39) as well as regarding the mean frequency (p = 0.004, r = 0.48) and amplitude variation of MMGpect (p = 0.033, r = 0.37). The mean (M) and variation coefficient (CV) of slope of ACC differed significantly (M: p = 0.022, r = 0.33; CV: p = 0.004, r = 0.43). All other parameters showed no significant differences between PD and controls. It remains open, if this altered mechanical muscular output is reproducible and specific for PD.

Study Design : Cross-sectional comparison. Introduction : Forearm supination range of motion is often limited by short or stiff pronators. Many studies have examined maximal isometric forearm supination torque (MIFST). However, there is little research comparing MIFST in two elbow positions between subjects with and without limited forearm supination range of motion (LSR). Purpose of the Study : The purpose of this study was to compare MIFST in two elbow positions (90º flexed elbow, extended elbow) between subjects with and without LSR. Methods : Thirteen right-handed subjects (seven men, six women) with LSR and 13 age- and gender-matched healthy controls participated in this study. The forearm supination range of motion and MIFST were measured using a Smart KEMA system. Two-way repeated-measures analysis of variance was used to compare MIFST in two elbow positions between subjects with and without LSR. Results : No significant difference between groups (p > .05) was found. However, there was an interaction effect between elbow position and group on MIFST (p < .05). Independent t-tests were used to confirm the simple effects. In the LSR group, the value of MIFST was significantly lower in the elbow-extended position than in the group without LSR (p < .05). Conclusions : These findings indicate that elbow position should be considered when assessing the strength or increasing the strength of the supinator muscle, especially in patients with LSR.

Objective: The research is aimed to investigate interactions between cardiovascular signals and to assess contributions of central and local mechanisms to skin blood flow regulation in upper and lower extremities at rest and under orthostasis., Methods: Heart rate variability, respiration, forearm, and foot skin blood flow were assessed at rest and during postural test in 25 healthy volunteers. Spectral analysis was performed. Phase synchronization degree of analyzed signals was determined by group phase wavelet coherence function., Results: Skin blood flow was lower on foot at rest and during postural test than on forearm. High-frequency component of heart rate variability was higher at ~0.3 Hz during postural test versus rest. Blood flow oscillation amplitudes on the foot were lower in frequency range including respiratory interval at rest than on forearm. Postural exposure increased amplitude of foot blood flow oscillations in respiratory interval and decreased amplitudes in cardiac interval versus rest. Orthostasis increased group wavelet phase coherence between foot blood flow and heart rate variability or respiration, as well as between forearm and foot blood flow at 0.3 Hz corresponding to respiration., Conclusions: The contribution of central mechanisms associated with respiration to blood flow regulation increased in lower extremities during orthostasis., (© 2020 John Wiley & Sons Ltd.)

Background: Gradual ulnar lengthening is the most commonly used procedure in the treatment of Masada type I/II deformity in patients with hereditary multiple osteochondromas. However, the treatment remains controversial for the recurrence of deformity in growing children. This study aims to evaluate the clinical and radiological outcomes of ulnar gradual lengthening in our clinic., Methods: We retrospectively reviewed patients who underwent ulnar lengthening by distraction osteogenesis from June 2008 to October 2017. The carrying angle (CA) and range of motion (ROM) of the forearm and elbow were clinically assessed, and the radial articular angle (RAA) and ulnar shortening (US) were radiologically assessed before lengthening, 2 months after external frame removal, and at the last follow-up., Results: The current study included 15 patients (17 forearms) with a mean age of 9.4 ± 2.3 years at the index surgery. The mean follow-up period was 4.2 ± 2.4 years. There were 9 patients (10 forearms) with Masada type I deformity and 6 patients (7 forearms) with Masada type IIb deformity. The mean amount of ulnar lengthening was 4.2 ± 1.2 cm. The mean RAA improved from 37 ± 8 to 30 ± 7° initially (p = 0.005) and relapsed to 34 ± 8° at the last follow-up (p = 0.255). There was a minimal deterioration of US yet significant improvement at the last follow-up compared to pre-op (p < 0.001). At the last follow-up, the mean forearm pronation and elbow flexion increased significantly (p < 0.001 and p = 0.013, respectively), and the mean carrying angle also improved significantly (p < 0.001). No patient with type IIb deformity achieved a concentric radial head reduction., Conclusions: Gradual ulnar lengthening significantly reduces cosmetic deformity and improves function in patients with Masada type I/IIb deformity. Our results supported early ulnar lengthening for patients with a tendency of dislocation of the radial head.

Background: The objective of this study was to predict the function of the forearm rotation on the basis of the articular surface of the sigmoid notch from three-dimensional reconstruction images., Methods: We retrospectively reviewed patients who underwent volar plate fixation for intra-articular distal radius fractures (DRFs) in our institution between January 2017 and July 2019. The 3D image of the sigmoid notch on the fractured distal radius was reconstructed and looked up from the ulnar view to determine the existence of gaps or steps. Patients with or without gaps/steps on the sigmoid notch were included in the case group or control group, respectively. The patients' basic data and postoperative data were collected and compared., Results: A total of 81 patients were included. There were 33 patients in the case group, and 48 patients in the control group. There was no significant difference between the two groups at baseline. The total range of motion (ROM) of rotation in the case group and control group was 130.3 ± 6.2° and 145.3 ± 6.7°, respectively (P < 0.001). The percentage of rotation ROM of contralateral limb in the case group and control group was 72.3 ± 3.1% and 80.7 ± 3.6%, respectively (P < 0.001). VAS during forearm rotation was 2.1 ± 0.7 in the case group, which is significantly higher than that in the control group (1.5 ± 0.5, P < 0.001)., Conclusion: This study proposed a new method to assess the articular surface of the sigmoid notch which is based on 3D reconstruction images. With the assistance of this method, we found that gaps or steps on the sigmoid notch not only limit forearm pronation rotation and supination rotation, but also cause apparent wrist pain during forearm rotation movement and poor wrist ability.

The one bone forearm is a salvage procedure for treatment of painful, instability of the forearm that results from trauma, congenital deformity, tumor, infection, and failed reconstructive efforts. By creating a stable osseous bridge between the ulnohumeral and radiocarpal joints, one bone forearm addresses defects in the bony architecture of the radius and ulna, their articulations, and their associated ligamentous complexes. Global instability of the forearm is a complex clinical pathology with few other answers. Choice of technique should be dictated by adjacent bone loss. This article presents experience with creating a one bone forearm in patients using synostosis procedures., Competing Interests: Disclosure The authors have nothing to disclose., (Copyright © 2020 Elsevier Inc. All rights reserved.)

New Findings: What is the central question of this study? β-Adrenergic receptor activation modulates cutaneous vasodilatation and sweating in young adults. In this study, we assessed whether age-related differences in β-adrenergic regulation of these responses exist and whether they differ between men and women. What is the main finding and its importance? We showed that ageing augmented β-adrenergic cutaneous vasodilatation, although the pattern of response differed between men and women. Ageing had no effect on β-adrenergic sweating in men or women. Our findings advance our understanding of age-related changes in the regulation of cutaneous vasodilatation and sweating and provide new directions for research on the significance of enhanced β-adrenergic cutaneous vasodilatation in older adults., Abstract: β-Adrenergic receptor agonists, such as isoprenaline, can induce cutaneous vasodilatation and sweating in young adults. Given that cutaneous vasodilatation and sweating responses to whole-body heating and to pharmacological agonists, such as acetylcholine, ATP and nicotine, can differ in older adults, we assessed whether ageing also modulates β-adrenergic cutaneous vasodilatation and sweating and whether responses differ between men and women. In the context of the latter, prior reports showed that the effects of ageing on cutaneous vasodilatation (evoked with ATP and nicotine) and sweating (stimulated by acetylcholine) were sex dependent. Thus, in the present study, we assessed the role of β-adrenergic receptor activation on forearm cutaneous vasodilatation and sweating in 11 young men (24 ± 4 years of age), 11 young women (23 ± 5 years of age), 11 older men (61 ± 8 years of age) and 11 older women (60 ± 8 years of age). Initially, a high dose (100 µm) of isoprenaline was administered via intradermal microdialysis for 5 min to induce maximal β-adrenergic sweating. Approximately 60 min after the washout period, three incremental doses of isoprenaline were administered (1, 10 and 100 µm, each for 25 min) to assess dose-dependent cutaneous vasodilatation. Isoprenaline-mediated cutaneous vasodilatation was greater in both older men and older women relative to their young counterparts. Augmented cutaneous vasodilatory responses were observed at 1 and 10 µm in women and at 100 µm in men. Isoprenaline-mediated sweating was unaffected by ageing, regardless of sex. We show that ageing augments β-adrenergic cutaneous vasodilatation differently in men and women, without influencing β-adrenergic sweating., (© 2020 The Authors. Experimental Physiology © 2020 The Physiological Society.)

Objective: The aim of this study was to assess the effect of central sensitization, induced by high frequency electrical stimulation of the skin (HFS), on pinprick-evoked brain potentials (PEPs) using robot-controlled mechanical pinprick stimulation and a stimulus evaluation task., Methods: In 16 healthy volunteers HFS was applied to the right volar forearm. Robot- controlled pinprick stimuli (64 mN) were applied before and 20 minutes after HFS to the skin surrounding the area onto which HFS was applied. During pinprick stimulation, the EEG was recorded and the quality of perception and perceived intensity of the pinprick stimuli was collected., Results: After HFS, the skin surrounding the site at which HFS was delivered showed increased mechanical pinprick sensitivity. Both the early-latency negative peak of PEPs and the later-latency peak were significantly increased after HFS., Conclusions: This study shows increased PEPs after HFS when they are elicited by a robot-controlled mechanical pinprick stimulator and participants are engaged in a stimulus evaluation task during pinprick stimulation., Significance: This is the first study that shows a significant increase of both PEP peaks, and therefore, it provides a preferred setup for assessing the function of mechanical nociceptive pathways in the context of central sensitization., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Context: The link between obesity and bone health is controversial. Most studies classify obesity based on body mass index. However, differences in metabolic status may affect bone health. Purpose: To explore the potential relationship of metabolic obesity with forearm bone mineral density (BMD) in a northern Chinese population. Methods: This is a retrospective study involving a total of 2122 subjects divided into four groups: a metabolically healthy normal-weight (MHNW) group, a metabolically healthy obesity (MHO) group, a metabolically unhealthy, but normal-weight (MUNW) group, and a metabolically unhealthy obesity (MUO) group. Analysis of covariance was performed to compare forearm BMD among the groups. The covariates included age, weight, and height, along with menopause status in women. Partial correlation analysis and multiple linear regression models were used to explore the associations of forearm BMD with clinical parameters. Results: Young middle-aged men with MHO had significantly higher forearm BMD than those in the MUO group. In addition, forearm BMD of young middle-aged women was higher in the MHNW group than in the MUNW group. Partial correlation analysis and multiple linear regression analysis suggested that homeostasis model assessment of insulin resistance (HOMA-IR) was negatively correlated with forearm BMD in young middle-aged male subjects with MUO, and waist circumference (WC) and low-density lipoprotein cholesterol (LDL-C) showed a significant negative relationship with forearm BMD in young middle-aged female MUNW subjects. Conclusions: Men in the MUO group and women in the MUNW group were more likely to have lower forearm BMD if they were of young middle age. Metabolic obesity could be a better method for defining obesity when exploring the relationship between obesity and bone health in Chinese individuals. WC, LDL-C, and insulin resistance might be negative predictors of bone health.

Background: Lateral elbow tendinopathy is associated with pain during gripping, with forearm/wrist orthoses prescribed for treatment., Objectives: To investigate the immediate effects of forearm and/or wrist orthoses on outcome measures of pain and function in individuals with lateral elbow tendinopathy., Design: Systematic review METHODS: Four electronic databases were searched to identify randomised controlled trials reporting the immediate effects of forearm and/or wrist orthoses on pain and function in individuals with lateral elbow tendinopathy. The quality of evidence was rated from high to very low, using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) for the primary outcomes. Where possible, standardised mean difference (SMD) and 95% confidence intervals were calculated to compare post measures between forearm and/or wrist orthoses and control/placebo conditions., Results: The search revealed 1965 studies, of which, seven randomised crossover trials were included. Using the GRADE approach there was low quality evidence revealing a significant decrease in pain during contraction (SMD range -0.65 to -0.83) with forearm orthoses compared to a control/placebo condition. Low quality evidence revealed improvements in pain-free grip strength with the use of a forearm orthosis (SMD range 0.24-0.38), but not maximal grip strength (SMD range 0.14-0.15). Low quality evidence revealed a static wrist orthosis did not improve pain-free grip strength (SMD -0.08) or maximal grip strength (SMD -0.22)., Conclusion: There is low quality evidence that forearm orthoses can immediately reduce pain during contraction and improve pain-free grip strength but not maximal grip strength in individuals with lateral elbow tendinopathy., Competing Interests: Declaration of competing interest The authors affirm that we have no conflict of interest or financial affiliation with any commercial organization that has a direct financial interest in any matter included in this manuscript., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: We hypothesized that a selective neural electrical stimulation of radial and median nerves enables the activation of functional movements in the paralyzed hand of individuals with tetraplegia. Compared to previous approaches for which up to 12 muscles were targeted through individual muscular stimulations, we focused on minimizing the number of implanted electrodes however providing almost all the needed and useful hand movements for subjects with complete tetraplegia., Methods: We performed acute experiments during scheduled surgeries of the upper limb with eligible subjects. We scanned a set of multicontact neural stimulation cuff electrode configurations, pre-computed through modeling simulations. We reported the obtained isolated and functional movements that were considered useful for the subject (different grasping movements)., Results: In eight subjects, we demonstrated that selective stimulation based on multicontact cuff electrodes and optimized current spreading over the active contacts provided isolated, compound, functional and strong movements; most importantly 3 out of 4 had isolated fingers or thumb flexion, one patient performed a Key Grip, another one the Power and Hook Grips, and the 2 last all the 3 Grips. Several configurations were needed to target different areas within the nerve to obtain all the envisioned movements. We further confirmed that the upper limb nerves have muscle specific fascicles, which makes it possible to activate isolated movements., Conclusions: The future goal is to provide patients with functional restoration of object grasping and releasing with a minimally invasive solution: only two cuff electrodes above the elbow. Ethics Committee / ANSM clearance prior to the beginning of the study (inclusion period 2016-2018): CPP Sud Méditerranée, #ID-RCB:2014-A01752-45, first acceptance 10th of February 2015, amended 12th of January 2016., Trial Registration: (www.clinicaltrials.gov): #NCT03721861, Retrospectively registered on 26th of October 2018.

Dynamic compression of the lateral antebrachial cutaneous nerve (LABCN) occurs with forearm pronation when the LABCN becomes compressed by the lateral margin of the biceps tendon. LABCN compression is a rare occurrence and is often overlooked as an etiology for forearm pain. While this entity has been described in several case reports in the orthopedic literature, it has not yet been described in radiology literature. We present a case of LABCN compression by the biceps tendon which was suggested by high-resolution magnetic resonance neurography in combination with the clinical findings and was subsequently confirmed and corrected surgically.

Background: The forearm is a common donor site, providing thin, pliable workhorse flaps for head and neck reconstruction. There are no prospective studies comparing the donor-site morbidity of the radial forearm flap to the ulnar artery perforator flap., Methods: All patients undergoing forearm free flaps were included for analysis and followed for a minimum of 1 year. Grip strength, sensation to light touch, temperature sensation, and wound healing were assessed., Results: A total of 98 patients were enrolled (radial forearm flap, n = 50; ulnar artery perforator flap, n = 48). There were three osteocutaneous radial forearm flaps performed. The donor site was closed primarily in one radial forearm flap patient and four ulnar artery perforator flap patients. The majority of donor sites were resurfaced with full-thickness skin grafts (radial forearm flap, n = 40; ulnar artery perforator flap, n = 44), and the remaining were closed with split-thickness skin grafts. Average grip strength compared to baseline measured at 1, 3, 6, and 12 months after surgery demonstrated no significant differences. All patients returned to baseline sensation to light touch with no long-term sensory deficits at 1 year. No patients suffered significant changes in temperature sensation or cold intolerance. Seven patients suffered partial skin graft loss (radial forearm flap, n = 5; ulnar artery perforator flap, n = 2); all of them healed secondarily with local wound care. There were no flap losses in the study., Conclusions: The radial forearm and ulnar artery perforator flaps are equivalent in terms of success and donor-site morbidity. Selection of flap should be based on need for pedicle length, flap bulk, concerns with radial or ulnar dominance, and surgeon comfort., Clinical Question/level of Evidence: Therapeutic, II.

Introduction: Prolonged limb blood flow occlusion (ie, tourniquet application during limb surgery) causes transient microvascular dysfunction. We examined the ability of a local nitric oxide donor (transdermal nitroglycerin) administered during prolonged cuff forearm occlusion to protect against microvascular dysfunction and to alter brachial artery dilation., Methods: Ten healthy men (28 ± 8 years) participated in the study. During the control visit, they completed three vascular occlusion tests in the right arm termed, PRE (5-min occlusion), POST immediate (20-min occlusion), and POST 30min (5-min occlusion). During the nitroglycerin visit, subjects completed the same vascular occlusion tests, but with a nitroglycerin patch placed over the contralateral forearm during the 20-min occlusion test. Micro- and macrovascular function were assessed using the near-infrared spectroscopy-derived reperfusion upslope (reperfusion slope, %.s -1 ) and flow-mediated dilation (%FMD), respectively., Results: The reperfusion slope (1.44 ± 0.72%.s -1 ) and the %FMD (15.0 ± 2.8%) of the POST immediate test of the nitroglycerin condition were significantly (P < .05) higher than the reperfusion slope (1.01 ± 0.37%.s -1 ) and %FMD (6.77 ± 1.8%) during the POST immediate test of the control visit., Conclusion: Transdermal nitroglycerin protects against ischemia-induced microvascular dysfunction and causes marked dilation of the brachial artery %FMD., (© 2019 John Wiley & Sons Ltd.)

Background: Measurement of skin involvement is essential for the diagnosis and assessment of prognosis and disease progression in systemic sclerosis (SSc). The modified Rodnan skin score (mRSS) is the gold standard measure of skin thickness, but it has been criticised for the lack of objectivity, poor inter-observer reproducibility and lack of sensitivity to change. Recently, shear-wave elastography (SWE) emerged as a promising tool for the objective and quantitative assessment of the skin in SSc patients. However, no studies have evaluated its sensitivity to change over time., Objective: To assess changes in skin stiffness in SSc patients using SWE during a 5-year follow-up., Methods: Skin stiffness [i.e. shear-wave velocity values (SWV) in metres per second] was assessed by SWE ultrasound (using virtual touch image quantification) at the 17 sites of the mRSS, in each participant, at baseline and follow-up. mRSS was performed at both time points. Differences between groups were analysed using the related-samples Wilcoxon signed-rank test and the Mann-Whitney U test., Results: We included 21 patients [85.7% females; mean age 56.3 (10.4) years at baseline, 57.1% with limited SSc] and 15 healthy controls [73.3% females; mean age 53.6 (14.1) years)]. The median follow-up was 4.9 (0.4) years. Skin stiffness decreased significantly at all Rodnan sites (p ≤ 0.001) (except in the fingers), in SSc patients, over time. The same phenomenon occurred in controls, but to a lesser degree, in terms of percentage change. The percentage reduction in skin stiffness varied in the different Rodnan sites and in different phases of the disease. In addition, SWV values also decreased significantly in 15/16 skin sites with local normal Rodnan at baseline, whereas local Rodnan skin score only changed significantly in the upper arm (p = 0.046) and forearm (p = 0.026)., Conclusion: This study provides first-time evidence suggesting that skin SWV values are more sensitive to change over time than mRSS and reduce significantly over time in SSc and normal controls.

Association between strength of nonadjacent muscles and bone mineral density is unclear. We used data from the National Health and Nutrition Examination Survey to convince the effect of grip strength on femoral neck and lumbar spine mineral density in the general US population. This research can broaden the area of muscle-bone interaction., Introduction: Grip test measures the maximum isotonic strength of hand and forearm and is often used as an indicator of general muscle strength. Muscle has been shown to exert positive effects on bone health, and studies are needed to test whether grip strength can be associated with bone mineral density of nonadjacent bones. The aim of this study is to assess whether grip strength is an independent predictor for bone mineral density (BMD) of femoral neck and total lumbar spine in the general US population., Methods: We used the data from the National Health and Nutrition Examination Survey (NHANES) 2013-2014, and 1850 participants aged from 40 to 80 years old were included in the analysis. Grip strength was recorded as the largest reading of three efforts of one's dominant hand using a handgrip dynamometer. Femoral neck and lumbar spine BMDs were measured through Dual-energy X-ray absorptiometry (DXA) scan. Univariate and multivariate linear regression analyses were done to examine the association between grip strength and BMDs., Results: After adjusting for age, ethnicity, body mass index (BMI), use of female hormones, smoking habit, drinking habit, family history of osteoporosis, use of calcium and vitamin D supplements, physical activity, serum calcium, and phosphorus levels, grip strength is associated with increased femoral neck and total lumbar spine BMDs in men (P < 0.001, P = 0.005), premenopausal women (P = 0.040, P = 0.014), and postmenopausal women (P = 0.016, P = 0.012)., Conclusions: Our results suggest that (1) grip strength can be associated with BMD of nonadjacent bones, and (2) grip strength of dominant hand can be an indicator of BMD in the general US population across genders and menopausal status.

The aim of the study was to assess the associations of bone mineral density and bone mass with physical activity levels, vitamin D, phosphorus, magnesium, total cholesterol and triglyceride concentration and body composition in young women and men. Physical activity has the most significant effect on bone status especially in men., Purpose: The aim of the study was to assess the associations of bone mineral density and bone mass with physical activity levels, vitamin D, phosphorus, magnesium, total cholesterol and triglyceride concentration and body composition in young women and men., Methods: One hundred subjects aged 19-24 years were included. Bone mineral density (BMD) in distal and proximal parts was evaluated by forearm densitometry. Body composition was analysed with the use of JAWON-Medical-x-scan. The following biochemical indicators were analysed: 25(OH) D and 1,25(OH)2D, magnesium, phosphorus, total cholesterol and triglycerides. Physical activity levels were assessed by interview., Results: Significant correlations between BMD and physical activity, skeletal muscle mass and body fat percentage were revealed in men. Among women, considerably weaker correlations of BMD with body composition and physical activity were noted than in men. BMD in the distal part correlated only with lean body mass, soft lean mass and body fat percentage. The strongest relationship between physical activity and bone mineral status parameters was noted for BMD in men. In women, physical activity did not affect BMD., Conclusions: Physical activity has the most significant effect on bone status especially in men.

Background: Multiple hereditary exostosis is a benign condition that can lead to significant forearm deformity secondary to physeal disturbances. As the child grows, the deformity can worsen as relative shortening of the ulna causes tethering, which may lead to increased radial articular angle, carpal slippage, and radial bowing, over time this tethering can also result in radial head subluxation or frank dislocation. Worsening of forearm deformities often require corrective reconstructive osteotomies to improve anatomic alignment and function. The purpose of this study is to evaluate the effectiveness of osteochondroma excision and distal ulnar tether release on clinical function, radiographic anatomic forearm alignment, and need for future corrective osteotomies., Methods: The authors reviewed a retrospective cohort of preadolescent patients who underwent distal ulna osteochondroma resection and ulnar tethering release (triangular fibrocartilage complex). Patients were invited back and prospectively evaluated for postoperative range of motion, pain scores, self-reported and parent-reported Disabilities of the Arm, Shoulder, and Hand (DASH) and Pediatric Outcomes Data Collection Instrument (PODCI) scores. In addition, preoperative and final postsurgical follow-up forearm x-rays were reviewed., Results: A total of 6 patients and 7 forearms were included in our study with an average age of 7.9 years at time of surgery. The average final follow-up was 7.4 years. With respect to range of motion, only passive radial deviation demonstrated improvement -20 to 14 degrees (P=0.01). Although there was not statistically significant change in radial articular angle, this study did find an improvement in carpal slip 75.7% to 53.8% (P=0.03). At final follow-up DASH score was 5.71 (σ=5.35), PODCI Global Function score was 95.2 (σ=5.81), and PODCI-Happiness score 98 (σ=2.74). Visual analogue scale appearance and visual analogue scale pain assessment were 1.67 (σ=1.21) and 1.00 (σ=1.26), respectively, at final follow-up. No patient in the cohort developed a radial head dislocation. Only one of 7 forearms required a corrective osteotomy within the study's follow-up time period., Conclusions: Surgical excision of forearm osteochondromas with ulnar tether release in the preadolescent patients improves carpal slip, may help to prevent subsequent surgical reconstruction and provides satisfactory clinical results at an average 7-year follow-up., Level of Evidence: Level III-therapeutic study.

Aims: There is a lack of an objective measurement tool for evaluating the quality of bowing performance in string players. The present study aimed to assess kinematic features of bow strokes performed by violinists and violists affected by bow arm dystonia, compared to healthy controls., Methods: Seven musicians with musician's dystonia and 20 healthy controls participated in the study. A 3D motion capture system was used to record repetitive bowing on a single string at fixed velocities. Temporal variability, an indirect indicator for motor disturbances, was computed in order to evaluate the musicians' performance during the repetitive movements. Simultaneously, muscular activity of essential flexors and extensors of the right arm was recorded using surface electromyography. Antagonistic muscular coactivation and temporal variability were analyzed in a multilevel linear model framework., Results: The results revealed generally higher forearm coactivation during upstrokes as compared to downstrokes in both groups. Whereas coactivation levels of the upper arm did not significantly differ between groups, we found increased forearm coactivation in patients during the more demanding playing conditions. Increased coactivation may represent an adaptive motor control strategy that is applied in order to reduce noise entering the motor system. Furthermore, affected musicians executed bow strokes with higher temporal variability than healthy controls, especially during fast playing., Conclusions: Building on these results we introduce a novel approach using simple kinematic measures to quantifying dystonic symptoms in string players. Even though dystonia patients showed higher temporal variability and elevated forearm coactivation, both variables were not correlated. This finding is discussed with respect to the heterogeneity of musicians' dystonia and its individual-specific manifestations in dystonic symptoms.

Background: Elbow stiffness commonly causes functional impairment and upper-limb disability. This study aimed to develop a new pathologic classification to further understand and standardize elbow arthrolysis from a new perspective, as well as to determine clinical outcomes., Methods: Extension-flexion dysfunction was classified into 4 types: EF I , tethers alone; EF II , tethers with blocks; EF III , articular malformation; and EF IV , bony ankylosis. Forearm rotation dysfunction was classified into 3 types: FR I , contracture alone; FR II , radial head malunion or nonunion; and FR III , proximal radioulnar bony ankylosis. A total of 216 patients with elbow stiffness were prospectively included and categorized preoperatively. All surgical procedures were performed by the same chief surgeon; different types underwent specific procedures. Patient data, elbow motion, and functional scores were analyzed., Results: Mean range of motion (ROM) increased from 40° preoperatively to 118° at final follow-up; 88% of patients regained ROM of 100° or greater. The forearm rotation arc (FRA) with forearm rotation dysfunction increased from a preoperative mean of 76° to 128°; 82% of patients regained an FRA of 100° or greater. The mean Mayo Elbow Performance Index (MEPI) increased from 63 to 91 points; the proportion of patients with good or excellent results was 95%. EF I patients had the best ROM (129°) and MEPI (93 points) and EF IV patients achieved the most-changed ROM (116°), whereas EF III patients had the worst ROM (104°) and MEPI (84 points) and the least-changed ROM (64°). The FRA was best in FR I patients (142°), followed by FR II patients (118°), and worst in FR III patients (82°); in contrast, the changed FRA was greatest in FR III patients (82°), followed by FR II patients (64°), and least in FR I patients (37°)., Conclusion: This study suggests that the proposed pathologic classification provides a new perspective on the understanding and standardization of elbow arthrolysis, providing satisfactory clinical outcomes., (Copyright © 2019 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: Previous work evaluating the pronator quadratus (PQ) muscle following volar plate fixation (VPF) of distal radius fractures (DRF) suggests that PQ repair often fails in the postoperative period. The purpose of this investigation was to assess PQ repair integrity following VPF of DRF using dynamic musculoskeletal ultrasonography. Methods: Twenty adult patients who underwent VPF of DRF with repair of the PQ with a minimum follow-up of 3 months underwent bilateral dynamic wrist ultrasonography. The integrity of the PQ repair, wrist range of motion (ROM) and strength, and functional outcome scores were assessed. Results: Mean patient age at the time of surgery was 59 ± 14 years, and 50% underwent VPF of their dominant wrist. Patients were evaluated at a mean 9 ± 4 months after VPF. All patients had an intact PQ repair. The volar plate was completely covered by the PQ in 55% of patients and was associated with a larger PQ when compared to patients with an incompletely covered volar plate ( P = .026). The flexor pollicis longus tendon was in contact with the volar plate in 20% of patients, with those patients demonstrating a trend toward significantly increased wrist flexion ( P = .053). No difference in ROM, strength, or outcome scores was noted among wrists with completely or incompletely covered volar plates. Conclusions: The PQ demonstrates substantial durability after repair following VPF. Wrist ROM, strength, and functional outcomes are similar in wrists in which the volar plate is completely or incompletely covered by the repaired PQ.

Renal hypouricemia sometimes leads to exercise-induced acute kidney injury (EIAKI) of unknown pathogenesis. In order to elucidate the various pathological conditions associated with hypouricemia, we analyzed the effects of low uric acid level on energy metabolism. We have modified semi-ischemic forearm exercise test and performed this test in one Japanese healthy volunteer, three patients with hereditary renal hypouricemia and one patient with hereditary xanthinuria of Czech origin. Forearm exercise was performed by squeezing a hand dynamometer with the sphygmomanometer cuff pressure kept at the mean arterial pressure. Venous blood was drawn five times (before exercise, 3, 10, 30, 45 minutes after the start of exercise) in each tests. The mean plasma lactate concentration increased from a baseline of 1.3 (range 0.7-1.8 mmol/L) to 4.0 (range 2.0-5.5 mmol/L) at 3 minutes after the start of exercise. The plasma hypoxanthine concentrations were quite low before exercise (0-2.9 μmol/L), but increased markedly to a range of 13.6-28.8 μmol/L after 10 minute forearm ischemia. Our protocol allowed us to conclude that the load was sufficient for observing metabolic changes in temporally hypoxia and in following recovery phase. The test was well tolerated and safe, we did not observe any adverse reactions including EIAKI.