Radial Shaft Research Articles

Dietary Saturated Fat and Bone Health in Young Adults: The Young Finns Cohort

Previous studies suggest that saturated fat (SFA) intake may negatively impact on bone. However, few human studies on the topic exist. Women and men aged 31–46 years from the Cardiovascular Risk in Young Finns study attended the peripheral quantitative computed tomography and ultrasound bone measurements in 2008 (n = 1884–1953, ~ 56% women). In addition, fracture diagnoses in 1980–2018 were searched for the national health care registers and 431 participants had at least one fracture. Food consumption was gathered with the 48-h dietary recall interviews and food frequency questionnaire in 1980–2007. In the present study, radial, tibial, and calcaneal bone traits, and fractures were examined relative to the long-term intake of SFA. No consistent associations were seen between bone outcomes and SFA intake that would have replicated in both women and men. The only evidence for differential distributions was seen in cortical density and cortical-to-total area ratio at the radial shaft, and speed of sound at the calcaneus, which were 0.1–0.4% higher in women in the lowest tertile of SFA intake compared with the highest tertile. In addition, among men, the odds ratio (OR) of fractures was greater in the second (OR 1.86, 95% confidence interval (CI) 1.03–3.33) and third tertile of SFA intake (OR 2.45, 95% CI 1.38–4.36) compared with the lowest tertile, independently of many risk factors of osteoporosis. In this observational study, we found no robust evidence of the associations of dietary long-term SFA intake with bone outcomes. Therefore, additional studies are needed to confirm the association of dietary SFA with bone health in humans.

Quantitative Analysis of the Volar Ulnar Corner of the Distal Radius: A Reference for Intraoperative Distal Radius Fracture Reduction

The reduction of distal radius fractures using volar locking plate fixation can be performed by securing the plate to the distal fragments and then levering the plate to the radial shaft. Oblique placement of the plate on the radial shaft may lead to malreduction. The aim of this study was to evaluate parameters that can be used for the assessment of intraoperative distal radius fracture reduction using "distal-first" volar plate fixation, especially the geometry of the ulnar corner. The prevalence of Tolat distal radioulnar joint (DRUJ) types was determined, and the angles of the volar corner were quantitatively described. Three hundred seventy-five adult patients with a conventional wrist radiograph in their medical chart were identified. From this cohort, 50 radiographs of each Tolat DRUJ type were quantitatively analyzed using 4 angles. The probability density of each angle was described using Kernel density estimation graphs. A multivariable analysis was used to study the association between the 4 angles and Tolat DRUJ types and other patient factors. One hundred fifty-one patients (40%) had a wrist with type 1 DRUJ, 147 (39%) had a wrist with type 2 DRUJ, and 77 (21%) had a wrist with type 3 DRUJ. The measurements of the distal ulnar corner, volar ulnar corner, and DRUJ angulation were significantly different among each Tolat DRUJ type. The median lunate facet inclination, relative to the axis of the radial shaft, measured 14° (interquartile range, 12°-16°) across all the Tolat DRUJ types. The prevalence of Tolat type 1, 2, and 3 DRUJ was 40%, 39%, and 21%, respectively. The angles of the volar ulnar corner varied with each DRUJ type. Because the lunate facet inclination was relatively consistent among all the Tolat DRUJ types, this angle may be useful as a reference for "distal-first" distal radius volar plating.

Outcomes associated with proton pump inhibitors and distal radius fractures: A post-hoc comparative analysis

Long-term, high-dose, daily proton pump inhibitors (PPI) may impact outcomes associated with distal radius fractures (DRF). The hypothesis was that differences existed in patient demographics, but there existed no differences in injury patterns, interventions, post-operative complications, and patient-reported outcomes between patients not on a PPI and patients on a PPI with a DRF. MethodsAn IRB-approved, post-hoc analysis of patients with DRF from 2012 through 2018 was performed. Patients included were age ≥18 years, sustained a DRF, had completed medical and medication records, Quick Disabilities of the Arm, Shoulder and Hand (DASH) scores, Global Assessment of Functioning (GAF) scores, visual analogue scale (VAS) pain scores, and a minimum of 1-year follow-up. Patients were stratified into two cohorts. Cohort one patients had no prescription or over-the-counter PPI use (no PPI cohort). Cohort two patients had adherence to a long-term, high-dose, daily PPI (PPI cohort). ResultsTwo hundred and eighty-one DRF patients were included. Of these 281 patients, 240 were in the no PPI cohort and 41 were in the PPI cohort. Patients in the PPI cohort had more median nerve injuries (12% versus 3%, p = 0.025) and radial shaft fractures (5% versus 0%, p = 0.020), less contralateral upper extremity injuries (0% versus 4%, p = 0.001), and more post-operative nonunions (7% versus 1%, p = 0.029) compared to patients in the no PPI cohort. ConclusionsLong-term, high-dose, daily PPI's may be associated with more median nerve injuries and radial shaft fractures, less contralateral upper extremity injuries, and more post-operative nonunions compared to DRF patients not on a PPI.

A Cadaveric Study of Deep Branch of Radial Nerve at Arcade of Frohse

Background: The arcade of Frohse (AF) is the most common site for compression of the deep branch of the radial nerve (DBRN). During the surgical fixation of proximal radial shaft fracture, there is a chance of accidental injury to DBRN near the arcade. The objective of the study was to describe the nature of AF, to provide the superficial surgical landmark for DBRN at AF, and to indicate the appropriate position of the forearm for the surgical approach in fracture proximal radial shaft surgery. Methodology: The present study was done on 50 upper extremities preserved in 10% formalin. The studied parameters were morphology of AF, forearm length, the distance between the lateral epicondyle and the DBRN at AF, arcade ratio and the distance of DBRN at AF to the biceps tendon in pronated and supinated forearm. Results: In 50 upper extremities, the AF was tendinous in 27 limbs (54%), musculotendinous in 19 limbs (38%), and membranous in 4 limbs (8%). The mean forearm length was 234.43 mm. The mean distance from the DBRN to the lateral epicondyle was 48.98 mm. The mean arcade ratio was 0.208 mm. At AF, the mean distance from DBRN to the biceps tendon in pronation and supination was 12.72 mm and 18.98 mm, respectively. Conclusion: The most common type of AF is tendinous type. The mean arcade ratio derived from our study was 0.208. It is suggested that the terminal supination of the forearm is the appropriate position for surgical reduction and fixation of proximal radial shaft fracture through the ventral (Henry's) approach.

Investigation of Radial Shaft Seal Swelling Using a Special Tribometer and Magnetic Resonance Imaging.

Compatibility between the rubber material of radial shaft seals and the lubricants to be sealed is an important requirement that customers demand of their lubricant suppliers. Among other effects that may result from incompatibility, the penetration of lubricant components into the rubber (swelling) can impair the seal’s functionality due to changes in its geometry and mechanical behavior. Typically, the penetration of a lubricant into an elastomer is evaluated after an immersion test using volumetric, gravimetric, and extraction measurements. Due to the small changes that need to be detected, such methods may not be sufficient to obtain meaningful results. In this contribution, we use magnetic resonance imaging (MRI) to investigate swelling on special tribometer samples as well as a radial shaft seal that were previously used in component tests. Several combinations of rubbers and lubricants that have proven to be compatible were tested in addition to combinations with expected incompatibilities in real applications. The results indicate that MRI measurements can be used to quantify the penetration depth and potentially also the velocity with which the lubricant diffuses into the rubber, thereby yielding detailed insights into the swelling process of the seal.

Effects of PMMA spacer loaded with varying vancomycin concentrations on bone regeneration in the Masquelet technique

Whether antibiotics should be included remains greatly debated in Masquelet technique. This study intended to determine the effect of polymethyl methacrylate (PMMA) spacer loaded with different vancomycin concentrations on bone defect repair. Hollow cylindrical spacers consisting of PMMA and varying vancomycin concentrations (0, 1, 2, 4, 6, 8, and 10 g) were prepared. Critical bone defects of rabbits were created at the radial shaft, and spacers were implanted and subsequently intramedullary fixed with retrograde Kirschner’s wires (n = 4 for each vancomycin concentration). After 4 weeks, the induced membranes were opened and cancellous allografts were implanted into the defects. Eight weeks post-operatively, the results of X-ray, histology, and micro-CT revealed that some cortical bone was formed to bridge the gap and the bone marrow cavity was formed over time. Quantitatively, there was more new bone formation in the groups with a relatively lower vancomycin concentration (1–4 g) compared with that in the groups with a higher vancomycin concentration (6–10 g). Our findings suggested that PMMA spacers loaded with relatively lower vancomycin concentrations (1–4 g) did not interfere with new bone formation, whereas spacers loaded with relatively higher vancomycin concentrations (6–10 g) had negative effects on bone formation.

Machine Learning for Opportunistic Screening for Osteoporosis from CT Scans of the Wrist and Forearm.

Background: We investigated whether opportunistic screening for osteoporosis can be done from computed tomography (CT) scans of the wrist/forearm using machine learning. Methods: A retrospective study of 196 patients aged 50 years or greater who underwent CT scans of the wrist/forearm and dual-energy X-ray absorptiometry (DEXA) scans within 12 months of each other was performed. Volumetric segmentation of the forearm, carpal, and metacarpal bones was performed to obtain the mean CT attenuation of each bone. The correlations of the CT attenuations of each of the wrist/forearm bones and their correlations to the DEXA measurements were calculated. The study was divided into training/validation (n = 96) and test (n = 100) datasets. The performance of multivariable support vector machines (SVMs) was evaluated in the test dataset and compared to the CT attenuation of the distal third of the radial shaft (radius 33%). Results: There were positive correlations between each of the CT attenuations of the wrist/forearm bones, and with DEXA measurements. A threshold hamate CT attenuation of 170.2 Hounsfield units had a sensitivity of 69.2% and a specificity of 77.1% for identifying patients with osteoporosis. The radial-basis-function (RBF) kernel SVM (AUC = 0.818) was the best for predicting osteoporosis with a higher AUC than other models and better than the radius 33% (AUC = 0.576) (p = 0.020). Conclusions: Opportunistic screening for osteoporosis could be performed using CT scans of the wrist/forearm. Multivariable machine learning techniques, such as SVM with RBF kernels, that use data from multiple bones were more accurate than using the CT attenuation of a single bone.

Delayed radial head dislocation after radial shaft fracture fixation: a case report and review of the literature

BackgroundIpsilateral fracture of the radial shaft with dislocation of the radial head was a rare injury, but a delayed radial head dislocation after radial shaft fracture fixation was more extremely rare.Case presentationA 39-year-old man fell from the height on his outstretched hand and injured his left, non-dominant forearm. Preoperative radiographs demonstrated a comminuted fracture of the proximal third of the radius but with no apparent dislocation of the distal or proximal radioulnar joints or the elbow. Seven days after the injury, the radius was fixed with a reconstruction locking plate, and the immediate postoperative radiograph revealed a satisfactory reduction. However, a radiograph done at the 4th week postoperatively showed that the radial head dislocated. Manual reduction under anesthesia was tried but failed and the patient refused to take another open surgery. The patient had an acceptable range of motion 12 months after the surgery: elbow flexion 120°, full elbow extension, forearm pronation 80°, forearm supination 80°, but he complained the pain around the elbow.ConclusionIn the case of radial shaft fracture especially the when occurs at the proximal third of the radial shaft, even if the radiograph does not show the injury of the proximal radioulnar joint, we should also make a thorough examination of the proximal radioulnar joint. If the radial head dislocation is not initially diagnosed or treated late, a delayed dislocation would be very difficult to manage with a poor expected outcome.

Forearm Plate Fixation: Should Plates Be Removed?

Refracture after both bone forearm fracture fixation may vary with or without plate removal. We tested the null hypothesis that there is no difference in the rate of refracture in patients who have undergone open reduction and internal fixation of a diaphyseal forearm bone who have retained implants versus removed implants. We also studied factors associated with plate removal. We retrospectively identified 645 adult patients with a total of 925 primary fractures that underwent primary plate fixation of an ulnar or radial shaft fracture between 2002 and 2015 at a single institutional system. Patients with nonunion, pathological fracture or infection were excluded. Independent factors associated with refracture and plate removal were identified using multivariable analysis. Refractures occurred in 6.3% of the fractures that had forearm implant removal, compared to 2.1% of the fractures with retained plates. Refractures were independently associated with plate removal (OR: 3.7, 95% CI: 1.2-11.7, P=0.023) and was more frequent in the radius (OR: 2.4, 95% CI: 1.0-5.8, P=0.06). A refracture after implant removal occurred within 3 months after removal. Ulnar plates were removed more often compared to radial plates (OR: 2.6, 95% CI: 1.4-4.7, P=0.002) as were plates used for type A fractures compared to type C fractures (OR: 3.2, 95% CI: 1.1-9.2, P=0.032). The rate of refracture is higher after plate removal compared to patients who did not have plates removed. Although uncommon, refractures of the radius tend to be more common than a refracture of the ulna. If the implant is symptomatic on the ulnar side, it may be preferable to remove the ulnar implant and retain the radius implant rather than remove both plates when possible. Furthermore, limiting strenuous activity for three months after implant removal is a consideration.

En bloc resection and vascularized ulnar pedicle graft reconstruction with plate fixation for giant cell tumour of the distal radius.

We retrospectively reviewed the medical records of ten patients (five men and five women) who were treated in our unit for Campanacci Grade III giant cell tumour of the distal radius between July 2017 and December 2019. Following en bloc resection of a giant cell tumour of the distal radius, the wrist was reconstructed by transposing a vascularized pedicle graft from the ipsilateral ulnar shaft. The graft was fixed to the radial shaft and proximal carpal row with plates. At a mean follow-up of 23.5 months (range 18 to 31), bony union was achieved in all cases and there were no tumour recurrences. All patients had a good range of pronation and supination, but flexion and extension of the wrist was limited. DASH scores ranged from 5 to 11. This reconstruction method is a safe and effective procedure that provides good aesthetic outcomes, removes the need for microvascular techniques and reduces donor site morbidity.Level of evidence: IV.

The sealing mechanism of radial lip seals: A numerical study of the tangential distortion of the sealing edge

The sealing behaviour of elastomeric radial lip seals is essentially affected by the sealing mechanism in the contact area between the sealing edge and the shaft surface. The relative motion between radial lip seal and shaft deforms the sealing edge tangentially in the circumferential direction. This mechanical deformation is considered essential for the sealing mechanism. In this study, a numerical approach is employed to simulate this deformation. A three-dimensional multiscale model serves this purpose. The radial lip seal geometry is described on the macro-scale. On the micro-scale, an artificial rough surface with a stochastic roughness distribution is applied to an ideal sealing edge surface. A new meshing algorithm is used to discretise different sealing edge surfaces and automatically generates structured hexahedral meshes of the sealing edges. Mesh transitions connect the resulting finely meshed sealing edge to the coarsely meshed global macro-scale mesh of the radial lip seal. The paper introduces the modelling method used to simulate the deformation of radial lip seals. Results are presented and discussed with reference to the sealing behaviour. This contributes to a better understanding of the sealing mechanism of radial lip seals. Keywords: radial lip seal, finite element analysis, surface roughness, elastic deformation, elastomers.

Level of Sagittal Plane Fit of Plates on the Radial Shaft: A Cadaveric Study Comparing Precontoured and Straight Titanium Plates.

During radial shaft fracture fixation, it is important to contour the plate appropriately to restore the radial bow in order to maintain normal forearm mechanics and motion. The aim of this study was to investigate the fit of precontoured radial shaft plates versus surgeon-contoured plates. Six 10-hole Acumed® precontoured volar and dorsolateral radius plates and twelve 10-hole Synthes straight titanium 3.5 mm LC-DCP plates were drilled with arrays of 1.5 mm diameter holes to permit measurement of the plate distance off bone. Plates were applied to 6 cadaver radii and secured with a screw on each end. Three plate conditions were tested: precontoured plates, precontoured plates with further surgeon contouring, and straight plates with surgeon contouring. Surgeon contouring time for each plate was recorded. Each plate was divided into 3 equal regions, and the average distance gaps for each region and the entire plate were calculated. For the volar side, precontoured plates had a larger total gap compared to that plate with additional surgeon contouring (1.4 mm difference) and the straight surgeon-contoured plates (1.2 mm difference). On the dorsal side, there was no difference in fit between the 3 plate conditions at any location. No differences were found in plate contouring times. The precontoured dorsal plate fit was as good as the surgeon-contoured plates indicating this plate could potentially be used in fracture surgery without further bending. The precontoured volar plate was under-contoured, on average, and would likely require further bending to restore the radial bow.

Optimal screw length in volar locking plate osteosynthesis for distal radius fractures: a systematic review.

Fractures of the distal radius represent the most common fracture of the upper limb, and can be managed surgically with volar locking plate osteosynthesis (VLPO). Uncertainty remains regarding the optimal length of the distal locking screws. The aim of this study was to determine the optimal VLPO screw length which provided adequate stability while minimizing complications. A systematic review of relevant literature published within Cochrane, PubMed, MEDLINE and Embase, including studies up to April 2020, was performed using the Preferred Reporting Items for Systemic Reviews and Meta-analysis (PRISMA) guidelines. Studies were included if they investigated distal radius fracture fixation with VLPO, screw lengths, complications, and associated imaging. Search results identified 664 relevant studies, of which 14 studies examining 926 radii were included for review. Synthesis revealed that unicortical locking fixation with screws ~75% the depth of the radius, or 2 mm short of the dorsal cortex, provided equivalent stability to bicortical fixation. The lunate may be used as a proxy to determine radial depth at each quartile column. Inadvertent screw protrusion can be assessed by taking four images intra-operatively; anteroposterior (AP), lateral, 45° supinated and dorsal tangential views (DTVs). Radial shaft screws can have up to 2 mm prominence with no clinical significance. Unicortical locking fixation at least 75% the depth of the distal radius provides equivalent stability to bicortical fixation in extra-articular fractures with lower complication rates. Imaging should be used to confirm that penetration of the dorsal cortex has not occurred.

Einfluss von Gruppe I Grundölen auf die Elastomerverträglichkeit von Radialwellendichtringen

Gear oils on the basis of Group I base oils are the most widely used lubricant in industrial drive systems. With dynamic friction torque tests, the influence of Group I base oils from different regions/refineries on elastomer compatibility of radial shaft seals is investigated by dynamic friction torque tests. The results show a significant influence of base oil on the development of frictional torque in the sealing gap and the elastomer compatibility.

Traitement de la pseudarthrose diaphysaire de l’avant-bras : greffe osseuse autologue iliaque corticospongieuse et fixation par plaque verrouillée

IntroductionStudies conducted on forearm bone diaphysis nonunion are limited due to the rarity of this condition. The present study aimed to evaluate the outcome of our technique using autologous iliac corticocancellous bone graft fixed by locking plate system for the forearm bone diaphyseal nonunion without infection. Patients and methodsWe treated eight patients with nonunion of radial or ulnar shaft fracture (four men, four women) aged 38 years (range: 18–52 years) on average. The average follow-up period was 18 months (range: 12–24 months). In our technique, we applied the locking plate to the diaphyseal bone fragment, before grafting the bone block to the nonunion site. After excision of sclerotic ununited bone, the autologous iliac corticocancellous bone was grafted to the defect and fixed with single locking screw. Pain, grip strength, and disabilities of the arm, shoulder, and hand (DASH) score were measured and compared before and 12 months after the surgery. Radiographs were taken at each follow-up, and the time of bony union was determined. ResultsThe mean time to radiological union was 4.2 months (range: 3–6 months), and bony union was achieved in all cases within 6 months. All measured values, visual analog scale, DASH score, and grip strength, were significantly improved at 12 months after surgery (p<0.05). No minor/major complications including infection, nonunion, or malunion were reported. ConclusionsLocking compression plate fixation and autologous iliac corticocancellous bone grafting with a holding locking screw appears to be a reliable primary procedure for nonunion of the forearm diaphyseal fracture without infection. Level of evidenceIV; Therapeutic study.

Estimation of radial shaft seal, oil drag and windage loss in twin screw oil injected compressor

The objective of this paper is to study the mechanical power loss arising from radial shaft seal, oil drag, and windage within the twin-screw oil-injected screw compressor. The previous papers in the series presented the evaluation of power loss due to the gears and bearings where it was found that the calculated total power loss was underestimated when compared to the experimental results for different sizes of compressors and different operating conditions. This indicates that few additional contributing elements were missing and needed due consideration to enhance the prediction. Literature review of the basic fluid dynamics and transmission gears confirms that oil drag loss and windage loss can also contribute to the power loss considerably.This paper presents a review of a few methods for the prediction of the radial shaft seal, oil drag, and windage loss. Predictions with the use of these methods and their comparison with the experimental results are analysed in this paper. Experimental results of three different sizes of the compressors tested in laboratory conditions were taken as reference for the comparison at different operating speeds and pressure ratios. The analysis helps to understand the contribution of each element of the power loss which can help a designer to optimally design a screw compressor.

Effect of different forearm positions on fragment rotation in extra-articular distal radius fractures: A cadaveric study.

The aim of the study was to investigate the effect of different arm positions (hand pronation/supination and elbow flexion/extension) on fragment rotation in extra-articular distal radius fractures in a cadaveric model. In this study, ten fresh-frozen cadaveric upper extremities from five donors with a mean age of 69 ± 12 years were used. Two cortical pins were inserted in the radius and the ulna. In a custom-made device, different forearm (30°, 60°, and 90° of pronation and supination) and elbow positions (full extension) were tested, using a fluoroscopic analysis. The degree of malrotation between the two pins was measured in these positions. At the last test sequence, the tendon of the brachioradialis muscle was released. A significant difference was found in concerns of the rotational angle between the distal fragment and the radial shaft at different degrees of pronation and supination if the elbow joint was in an extended and flexed position. The release of the brachioradialis tendon did not show any effect. The results of this study supported that rotational malpositions in distal radius fractures can be decreased if the forearm is in a neutral position. Accordingly, the forearm should be in a neutral position while initially immobilization in a plaster splint is performed.

Unusual Combination of Postero-Lateral Elbow Dislocation and Ipsilateral Diaphyseal Radial Fracture: A Case Report and Review of Literature

The combination of a radial diaphysis fracture and ipsilateral elbow dislocation is a rare lesion. Only a few similar cases have been reported in the literature. Such injuries need a concentric reduction of the dislocation and an anatomical fixation of the radius for optimal functional outcomes. The radial fracture and ipsilateral dislocation of the elbow were probably caused by forearm hypersupination with extension of the elbow. Closed reduction of the elbow and operative stabilization of radial fracture were done with good clinical, radiological and functional outcomes in 8 months follow-up period. We discuss through a clinical case of a radial shaft fracture unusually associated with postero-lateral elbow dislocation and through a review of the literature the clinical aspects, the mechanism, treatment and the evolving profile of this particular lesion.

Dorsal Thompson: Approach to the Proximal Radial Shaft.

Treatment principles in the management of radial shaft fractures, congruent with all fracture care, are to restore anatomy and function of the limb. Radial shaft fractures are unique in that preserving the anatomic bow of the radius, which allows for its rotation around the ulna during pronation and supination, is essential for proper function. The 2 main approaches for exposure of the proximal or middle third radial diaphyseal fractures are the volar "Henry" and the dorsal "Thompson." This article highlights the benefits of the dorsal Thompson approach, describes the key points of the operative technique, which allow for protection of the posterior interosseous nerve, and provides an overview of the measurable outcomes when using this approach. In the accompanying video, the steps of operative exposure to the proximal radial shaft with careful avoidance of the posterior interosseous nerve are demonstrated.

A new quantitative evaluation system for distal radioulnar joint instability using a three-dimensional electromagnetic sensor

BackgroundThe accurate assessment of distal radioulnar joint (DRUJ) instability is still challenging as there is no established objective evaluation method. This study aimed to develop a noninvasive measurement method using a three-dimensional electromagnetic sensor system (EMS) to quantitatively assess and characterize the normal DRUJ movement in healthy volunteers.MethodsThe DRUJ movement was mimicked using both a block model and saw bone. Movement of the models was measured by EMS, and the accuracy and reproducibility of the measurements were assessed. In vivo measurement was performed in a sitting position with the elbow flexed and the forearm pronated. One sensor each was attached to the distal radial shaft and the ulnar head. The examiners fixed the distal radius and the carpal bones, moved the ulnar head from the dorsal to the volar side and measured the dorsovolar translation. The volar translation was measured by EMS and ultrasonography, and the correlation coefficient was calculated. The dorsovolar translation was evaluated in 14 healthy volunteers (7 men and 7 women) by three hand surgeons. The intraclass and inter-rater correlation coefficients (ICCs), the differences between the dominant and non-dominant sides and between men and women were assessed.ResultsThe accuracy and reproducibility assessment results of the EMS showed high accuracy and reproducibility. In the comparison between EMS and ultrasonography, the correlation coefficient was 0.920 (p = 0.16 × 10-3). The ICC (1,5) for the intra-rater reliability was 0.856, and the ICC (2,5) for inter-rater reliability was 0.868. The mean ulnar head translation and difference between dominant and non-dominant sides were 6.00 ± 1.16 mm (mean ± SD) and − 0.12 ± 0.40 mm, respectively. There were no significant differences between any of the parameters.ConclusionsA new measurement method using EMS could evaluate DRUJ movement with high accuracy, reproducibility, and intra- and inter-rater reliability. In healthy volunteers, the dorsovolar ulnar head translation was 6.00 mm. The difference between the dominant and non-dominant sides was < 1.0 mm with no significant difference. EMS provided an objective, non-invasive, real-time assessment of dynamic changes in the DRUJ. These findings could be useful in the treatment of patients with DRUJ instability.