Maximum one-handed pull force and its relation to shoulder geometry

2005 ◽  
Vol 4 (3) ◽  
pp. 143-155
Author(s):  
Krystyna Gielo-Perczak
Keyword(s):  
Maximum Voluntary Contraction ◽  
Frontal Plane ◽  
Voluntary Contraction ◽  
Resonance Imaging ◽  
Upper Arm ◽  
Shoulder Joints ◽  
Mri Scans ◽  
The Mean ◽  
Shoulder Geometry ◽  
Magnetic Resonance Imaging Mri

The current study proposes a method of geometrical description of the shoulder articulating surfaces in order to deduce an unrecognized relationship between shoulder geometry and strength during a one-handed pulling task. The paper reports the results of a study of the strength of 12 participants during one-handed pulling correlated with the geometries of their shoulder joints derived from magnetic resonance imaging (MRI) scans. The measurements of a mean force during pulling were recorded when an upper arm was adducted in the frontal plane from 5 to 30 degrees during maximum voluntary contraction (MVC). It was observed in the study that an area determined by the height and width of the glenoid fossa closely relates to the mean force during pulling.

scholarly journals Early MRI outcomes in participants with a first clinical demyelinating event at risk of multiple sclerosis in the ORACLE-MS study

2021 ◽  
Vol 7 (1) ◽  
pp. 205521732199085
Author(s):  
Mark S Freedman ◽  
Patricia K Coyle ◽  
Giancarlo Comi ◽  
Susan L Scarberry ◽  
Doris Damian ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Multiple Sclerosis ◽  
Resonance Imaging ◽  
Phase 3 ◽  
Post Hoc Analysis ◽  
T2 Lesions ◽  
Mri Scans ◽  
The Mean ◽  
Magnetic Resonance Imaging Mri ◽  
Post Hoc

Background In the Phase 3, 96-week ORACLE-MS study, cladribine tablets 10 mg (3.5 or 5.25 mg/kg cumulative dosage over two years) significantly reduced lesions associated with multiple sclerosis versus placebo in participants following a first clinical demyelinating event (FCDE). Objective To determine the timing of effects of cladribine tablets on lesion activity assessed by magnetic resonance imaging (MRI). Methods This post hoc analysis assessed the effect of cladribine tablets versus placebo in ORACLE-MS on secondary MRI endpoints including T1 gadolinium-enhancing (Gd+), new or enlarging T2 lesions, and combined unique active lesions assessed on MRI scans performed at screening and every 3 months thereafter. Results Compared to placebo, cladribine tablets 3.5 mg/kg treatment appeared to lead to a trend of reductions in the mean number of T1 Gd+ lesions by Week 13 (first post-baseline scan: 0.37 vs. 1.00), new or enlarging T2 (0.20 vs. 1.01) and combined unique active (0.29 vs. 1.91) lesions by Week 24. Low lesion counts were maintained with cladribine tablets throughout 96 weeks. Similar results were observed with the 5.25 mg/kg dosage. Conclusion In participants with an FCDE, cladribine tablets appeared to reduce lesion numbers within 13 weeks (time of first evaluation).

scholarly journals Switching from branded to generic glatiramer acetate: 15-month GATE trial extension results

2017 ◽  
Vol 23 (14) ◽  
pp. 1909-1917 ◽  
Author(s):  
Krzysztof Selmaj ◽  
Frederik Barkhof ◽  
Anna N Belova ◽  
Christian Wolf ◽  
Evelyn RW van den Tweel ◽  
...  
Keyword(s):  
Glatiramer Acetate ◽  
Efficacy And Safety ◽  
Resonance Imaging ◽  
Open Label ◽  
Double Blind ◽  
Disability Status ◽  
Mri Scans ◽  
The Mean ◽  
Magnetic Resonance Imaging Mri

Background: Open-label 15-month follow-up of the double-blind, placebo-controlled Glatiramer Acetate clinical Trial to assess Equivalence with Copaxone® (GATE) trial. Objective: To evaluate efficacy, safety, and tolerability of prolonged generic glatiramer acetate (GTR) treatment and to evaluate efficacy, safety, and tolerability of switching from brand glatiramer acetate (GA) to GTR treatment. Methods: A total of 729 patients received GTR 20 mg/mL daily. Safety was assessed at months 12, 15, 18, 21, and 24 and Expanded Disability Status Scale and magnetic resonance imaging (MRI) scans at months 12, 18, and 24. The presence of glatiramer anti-drug antibodies (ADAs) was tested at baseline and months 1, 3, 6, 9, 12, 18, and 24. Results: The mean number of gadolinium-enhancing lesions in the GTR/GTR and GA/GTR groups was similar at months 12, 18, and 24. The change in other MRI parameters was also similar in the GTR/GTR and GA/GTR groups. The annualized relapse rate (ARR) did not differ between the GTR/GTR and GA/GTR groups, 0.21 and 0.24, respectively. The incidence, spectrum, and severity of reported adverse events did not differ between the GTR/GTR and GA/GTR groups. Glatiramer ADA titers were similar in the GTR/GTR and GA/GTR groups. Conclusion: Efficacy and safety of GTR is maintained over 2 years. Additionally, switching from GA to GTR is safe and well tolerated.

Bioabsorbable Unsintered Hydroxyapatite/Poly-l-Lactic Acid Pin Fixation of Osteochondritis Dissecans in Adolescents: Initial Experiences

2020 ◽  
Author(s):  
Martin Georg Zeilinger ◽  
Christian Autenrieth ◽  
Kerstin Remmel ◽  
Alexander Schuh ◽  
Matthias Hammon ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Osteochondritis Dissecans ◽  
Clinical Results ◽  
Resonance Imaging ◽  
Pin Fixation ◽  
Mri Scans ◽  
Harris Score ◽  
The Mean ◽  
Magnetic Resonance Imaging Mri

Abstract Background This study sought to retrospectively evaluate the clinical and magnetic resonance imaging (MRI) outcomes of u-HA/PLLA pin (u-HA/PLLA: hydroxyapatite/poly-L-lactic acid) pin fixation of unstable osteochondritis dissecans (OCD) lesions of the knee. Methods Seven adolescent patients (four females and three males) with arthroscopically unstable OCD lesions of the knee were included. The mean age at diagnosis was 13.1 years. Clinical results were evaluated preoperatively and during follow-up using the Ogilvie-Harris score (0 – 15 points). MRI scans were performed preoperatively and during follow-up, with results evaluated using the Dipaola classification (grades 1 – 4). Mean follow-up time was 29 months. Results The median Ogilvie-Harris score improved from 13 points (range: 10 – 14 points) to 15 points (range: 13 – 15 points). Separately, the median Dipaola score improved from 3 points (range: 2 – 4 points) to 1 point (range: 1 – 4 points). No complications such as infection, synovitis, or intra-articular adhesion were observed. Conclusions Initial experiences using bioabsorbable u-HA/PLLA pins for the refixation of unstable OCD lesions in adolescents in the knee are promising, and MRI provides excellent monitoring of healing.

Distance of the Posterior Interosseous Nerve From the Bicipital (Radial) Tuberosity at Varying Positions of Forearm Rotation: A Magnetic Resonance Imaging Study With Clinical Implications

2021 ◽  
Vol 49 (5) ◽  
pp. 1152-1159
Author(s):  
Tyler A. Luthringer ◽  
David A. Bloom ◽  
David S. Klein ◽  
Samuel L. Baron ◽  
Erin F. Alaia ◽  
...  
Keyword(s):  
Anterior Approach ◽  
Single Incision ◽  
Biceps Tendon ◽  
Tendon Repair ◽  
Resonance Imaging ◽  
Forearm Rotation ◽  
Mri Scans ◽  
Biceps Tendon Repair ◽  
The Mean ◽  
Bicipital Tuberosity

Background: The proximity of the posterior interosseous nerve (PIN) to the bicipital tuberosity is clinically important in the increasingly popular anterior single-incision technique for distal biceps tendon repair. Maximal forearm supination is recommended during tendon reinsertion from the anterior approach to ensure the maximum protective distance of the PIN from the bicipital tuberosity. Purpose: To compare the location of the PIN on magnetic resonance imaging (MRI) relative to bicortical drill pin instrumentation for suspensory button fixation via the anterior single-incision approach in varying positions of forearm rotation. Study Design: Descriptive laboratory study. Methods: Axial, non–fat suppressed, T1-weighted MRI scans of the elbow were obtained in positions of maximal supination, neutral, and maximal pronation in 13 skeletally mature individuals. Distances were measured from the PIN to (1) the simulated path of an entering guidewire (GWE-PIN) and (2) the cortical starting point of the guidewire on the bicipital tuberosity (CSP-PIN) achievable from the single-incision approach. To radiographically define the location of the nerve relative to constant landmarks, measurements were also made from the PIN to (3) the prominent-most point on the bicipital tuberosity (BTP-PIN) and (4) a perpendicular plane trajectory from the bicipital tuberosity exiting the opposing radial cortex (PPT-PIN). All measurements were subsequently compared between positions of pronation, neutral, and supination. In supination only, BTP-PIN and PPT-PIN measurements were made and compared at 3 sequential axial levels to evaluate the longitudinal course of the nerve relative to the bicipital tuberosity. Results: Of the 13 study participants, mean age was 38.77 years, and mean body mass index was 25.58. Five participants were female, and 5 left and 8 right elbow MRI scans were reviewed. The GWE-PIN was significantly greater in supination (mean ± SD, 16.01 ± 2.9 mm) compared with pronation (13.66 ± 2.5 mm) ( P < .005). The mean CSP-PIN was significantly greater in supination (16.20 ± 2.8 mm) compared with pronation (14.18 ± 2.4 mm) ( P < .013).The mean PPT-PIN was significantly greater in supination (9.00 ± 3.0 mm) compared with both pronation (1.96 ± 1.2 mm; P < .001) and neutral (4.73 ± 2.6 mm; P < .001). The mean BTP-PIN was 20.54 ± 3.0, 20.81 ± 2.7, and 20.35 ± 2.9 mm in pronation, neutral, and supination, respectively, which did not significantly differ between positions. In supination, the proximal, midportion, and distal measurements of BTP-PIN did not significantly differ. The proximal PPT-PIN distance (9.08 ± 2.9 mm) was significantly greater than midportion PPT-PIN (5.85 ± 2.4 mm; P < .001) and distal BTP-PIN (2.27 ± 1.8 mm; P < .001). Conclusion: This MRI study supports existing evidence that supination protects the PIN from the entering guidewire instrumentation during anterior, single-incision biceps tendon repair using cortical button fixation. The distances between the entering guidewire trajectory and PIN show that guidewire-inflicted injury to the nerve is unlikely during the anterior single-incision approach. Clinical Relevance: When a safe technique is used, PIN injuries during anterior repair are likely the result of aberrant retractor placement, and we recommend against the use of retractors deep to the radial neck. Guidewire placement as close as possible to the anatomic footprint of the biceps tendon is safe from the anterior approach. MRI evaluation confirms that ulnar and proximal guidewire trajectory is the safest technique when using single-incision bicortical suspensory button fixation.

scholarly journals Magnetic resonance imaging (MRI) scans in patients with dorsal root ganglion stimulation

Pain Practice ◽  
2021 ◽  
Author(s):  
Marco Reining ◽  
Dirk Winkler ◽  
Joachim Boettcher ◽  
Juergen Meixensberger ◽  
Michael Kretzschmar
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Dorsal Root Ganglion ◽  
Dorsal Root ◽  
Resonance Imaging ◽  
Mri Scans ◽  
Magnetic Resonance Imaging Mri

Progress of leukoaraiosis is inhibited by correction of platelet hyper-aggregability

2005 ◽  
Vol 17 (4) ◽  
pp. 689-698 ◽  
Author(s):  
Shigekiyo Fujita ◽  
Tetsuro Kawaguchi ◽  
Toshiyuki Uehara ◽  
Kazuhito Fukushima
Keyword(s):  
Group Versus ◽  
Adenosine Diphosphate ◽  
White Matter Hyperintensity ◽  
Number Of Patients ◽  
Mri Scans ◽  
The Mean ◽  
The Difference ◽  
Magnetic Resonance Imaging Mri ◽  
Observation Period

Background: Platelet hyper-aggregability is an important risk factor for leukoaraiosis. In this study we investigated whether aggravation of leukoaraiosis can be controlled by means of long-term correction of platelet hyper-aggregability.Methods:Twenty-one patients with leukoaraiosis and uncorrected platelet hyper-aggregability were compared with 21 controls matched for age, grade of leukoaraiosis and observation period whose platelet hyper-aggregability was corrected. Platelet aggregability was estimated by an optical analytical method with a nine-stage display using two different concentrations each of adenosine diphosphate (ADP) and collagen (the double ADP method).Results:The mean observation period between two magnetic resonance imaging (MRI) scans for both groups was 4.1 years. In the non-corrected group, moderate to severe aggravation of leukoaraiosis was observed in a large number of patients. In the corrected group, only a small number of patients showed generally mild aggravation of leukoaraiosis. The number of patients showing aggravation of periventricular hyperintensity (PVH) was 7 in 21 in the non-corrected group versus 1 in 21 (p=0.022) in the corrected group, and for aggravation of deep white-matter hyperintensity, these values were 9 in 21 versus 4 in 21, respectively. Thus, the difference was more significant if the degree of aggravation was taken into account.Conclusion:The progress of leukoaraiosis is greatly inhibited by long-term correction of platelet hyper-aggregability.

A Mechanical Model Representation of the In Vivo Behaviour of Bulk Tissue

Volume 2 ◽  
2004 ◽  
Author(s):  
Serdar Aritan ◽  
S. Olutunde Oyadiji ◽  
Roger M. Bartlett
Keyword(s):  
Soft Tissues ◽  
Creep Behaviour ◽  
Maximum Voluntary Contraction ◽  
Testing Machine ◽  
Voluntary Contraction ◽  
Upper Arm ◽  
Creep Response ◽  
In Series ◽  
Bulk Tissue

The aim of this study was to characterise the bulk modulus properties of the upper arm under relaxed and controlled contraction which is defined as 25% of the maximum voluntary contraction. A new testing machine was designed to generate constant load on the upper arm and measure the deformation over time. The machine consists of a device which is effectively a cuff that applies controllable pressure on a 47 mm wide band of the upper arm. Six different loads (10, 20, 30, 40, 50 and 60 kgf) were applied over a period of time of up to a maximum of 120 seconds. The deflection-time curves obtained show strongly non-linear response of the bulk tissue. The non-linearity manifested by these deflection-time curves is in terms of both time- and load-dependency. For each load, the creep behaviour follows an exponential law typical of viscoelastic materials. At low loads (below 30kgf), the creep response increases fairly linearly as the load is increased from 10 kgf to 30 kgf. But at high loads (above 30 kgf), the creep response increases only slightly as the load is increased from 30 kgf to 60 kgf. Beyond a load of 60 kgf, the deflection or creep becomes negligible. This implies that the upper arm has reached the state of incompressibility. The creep behaviour of the upper arm was simulated using four Voigt viscoelastic models in series. The three obvious soft tissues of the upper arm, namely skin, fat and muscle, were modelled in series. The effects of blood vessels and connective tissue were also modelled in series with the other tissues.

Safety Issues in Magnetic Resonance Imaging Scan with Retention of Olympus Long Clips in the Gastrointestinal Tract

2021 ◽  
Vol 17 ◽  
Author(s):  
Cheng-Yi Wang ◽  
Wei-Chou Chang ◽  
Hsin-Hung Huang ◽  
Wei-Kuo Chang ◽  
Yu-Lueng Shih ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Magnetic Resonance Imaging Scan ◽  
Resonance Imaging ◽  
Endoscopic Clip ◽  
Serious Adverse Event ◽  
Safety Issues ◽  
Endoscopic Clips ◽  
Mri Scans ◽  
Magnetic Resonance Imaging Mri

Objective: Not all endoscopic clips are compatible with magnetic resonance imaging (MRI). The aim of this study is to investigate the safety of MRI-incompatible endoscopic clips in patients undergoing MRI scans. Methods: We retrospectively reviewed the medical records of patients who had received endoscopic clip placement of Olympus Long Clip MRI-incompatible clips and then had undergone MRI scans within two weeks in our hospital between 2014 and 2019. Results: A total of 44,292 patients had undergone an MRI examination at our hospital. Only 15 patients had MRI scans within two weeks after the endoscopic clip placement. Their median age was 65.5 years, and 12 of the 15 patients were men. At the time of the clip placement and MRI scan, four patients were taking anti-coagulation or anti-platelet agents. The indication for endoscopic clip placement of the 15 patients was mucosal/submucosal defect or hemorrhage and colonic perforation. Endoscopic clips were placed in the colon of 14 patients and in the stomach of only one patient for gastric hemorrhage. One patient experienced clip migration and three displayed artifacts in abdominal images. No patient complications of mortality, hemorrhage, or organ perforation occurred. Conclusion: No serious adverse event occurred during MRI scans of patients with MRI-incompatible clips in this study, suggesting that MRI-incompatible clips may be safe to use in MRI scans. However, this does not guarantee the safety of the Long Clip for MRI scans, as further tests are needed to verify that this clip is safe for use during MRI.

Magnetic Resonance Imaging to Investigate the Clinical Applicability of the Medial Femoral Trochlea Osteochondral Flap Within the Wrist

Hand ◽  
2022 ◽  
pp. 155894472110643
Author(s):  
Jimmy H. Daruwalla ◽  
Jan Skrok ◽  
Mitchell A. Pet ◽  
Aviram M. Giladi ◽  
James P. Higgins
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Sagittal Plane ◽  
Convex Surface ◽  
Radius Of Curvature ◽  
Resonance Imaging ◽  
Femoral Trochlea ◽  
Average Ratio ◽  
Mri Scans ◽  
Magnetic Resonance Imaging Mri

Background: The medial femoral trochlea (MFT) osteochondral flap is employed for reconstruction of unsalvageable scaphoid proximal pole nonunions. The convex surface of the cartilage-bearing proximal trochlea is used to replace the similarly contoured proximal scaphoid and articulate with the concave scaphoid fossa of the radius. A magnetic resonance imaging (MRI) comparison of the shape of the MFT as it relates to the native proximal scaphoid has not been previously performed. Our study aimed to quantifiably compare the shape of the MFT, proximal scaphoid, and scaphoid fossa. Methods: Using imaging processing software, we measured radius of curvature of the articular segments in MRI scans of 10 healthy subjects’ wrists and knees. Results: Compared with the scaphoid fossa, average ratio of the radius of circumference of the proximal scaphoid was 0.79 and 0.78 in the coronal and sagittal planes, respectively. Compared with the scaphoid fossa, average ratio of the radius of circumference of the MFT was 0.98 and 1.31 in the coronal and sagittal planes, respectively. The radius of curvature of the MFT was larger than the proximal scaphoid, in the coronal and sagittal planes. In the coronal plane, the MFT radius of curvature is nearly identical to the scaphoid fossa, a closer match than the scaphoid itself. In the sagittal plane, the radius of curvature of the MFT was larger than the radius of curvature of the scaphoid fossa. Conclusions: Our data suggest that the radius of curvature, in the sagittal and coronal planes, of the MFT and proximal scaphoid is disparate.

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