Biomechanical comparison of three fixation techniques used for four-corner arthrodesis

2011 ◽  
Vol 36 (7) ◽  
pp. 560-567 ◽  
Author(s):  
J. Kraisarin ◽  
D. G. Dennison ◽  
L. J. Berglund ◽  
K. N. An ◽  
A. Y. Shin
Keyword(s):  
Circular Plate ◽  
Clinical Results ◽  
Circular Plates ◽  
Wrist Flexion ◽  
Kirschner Wires ◽  
Biomechanical Behavior ◽  
Plate Group ◽  
Fixation Techniques ◽  
Biomechanical Comparison ◽  
Flexion And Extension

Clinical results following four-corner arthrodesis vary and suggest that nonunion may be related to certain fixation techniques. The purpose of our study was to examine the displacement between the lunate and capitate following a simulated four-corner arthrodesis with the hypothesis that three types of fixation (Kirschner wires, dorsal circular plate, and a locked dorsal circular plate) would allow different amounts of displacement during simulated wrist flexion and extension. Cadaver wrists with simulated four-corner arthrodeses were loaded cyclically either to implant failure or until the lunocapitate displacement exceeded 1 mm. The locked dorsal circular plate group was significantly more stable than the dorsal circular plate and K-wire groups ( p = 0.018 and p = 0.006). While these locked dorsal circular plates appear to be very stable our results are limited only to the biomechanical behavior of these fixation techniques within a cadaver model.

scholarly journals Mandibular Angle Fractures: A Clinical and Biomechanical Comparison—the Works of Ellis and Haug

2008 ◽  
Vol 1 (1) ◽  
pp. 31-38 ◽  
Author(s):  
Richard H. Haug ◽  
Bethany L. Serafin
Keyword(s):  
Substance Abuse ◽  
Clinical Results ◽  
Biological Factors ◽  
Mandibular Angle ◽  
Biomechanical Behavior ◽  
Angle Fractures ◽  
Behavioral Issue ◽  
Biomechanical Comparison ◽  
Insight Into

In a series of articles spanning 8 years, Ed Ellis reviewed the clinical results of the treatment of 478 mandibular angle fractures managed by eight different techniques. During a series of benchtop investigations employing polyurethane synthetic mandible replicas, Rich Haug investigated the biomechanical behavior of approximately 15 different techniques designed to reconstruct mandibular angle fractures. This article reviews these two series of investigations in an attempt to gain insight into the biomechanical and biological factors that affect the successful reconstruction of mandibular angle fractures. It appears that the current techniques used to reconstruct mandibular angle fractures are sound from the standpoint of biomechanics within a range of forces encountered during clinical function. It also appears that an unsuccessful reconstruction is based on a biological result of a behavioral issue such as noncompliance, substance abuse, and/or nutritional or immune compromise.

scholarly journals Biomechanical Comparison of Four Mandibular Angle Fracture Fixation Techniques

2015 ◽  
Vol 8 (2) ◽  
pp. 123-128 ◽  
Author(s):  
JoseLuis Muñante-Cardenas ◽  
LuisAugusto Passeri
Keyword(s):  
Test Group ◽  
Load Resistance ◽  
Mandibular Angle ◽  
Biomechanical Behavior ◽  
Mandibular Angle Fracture ◽  
Angle Fracture ◽  
Fixation Techniques ◽  
Angle Fractures ◽  
Biomechanical Comparison ◽  
Testing Group

The aim of this study was to make a comparison of the biomechanical behavior of four different internal fixation systems for mandibular angle fractures. A total of 40 polyurethane mandible replicas were employed with different fixation methods: group 1SP, one 2.0-mm four-hole miniplate; group 2PPL, two 2.0-mm four-hole parallel miniplates; group 3DP, one 3D 2.0-mm four-hole miniplate; and group 3DPP, one 3D 2.0-mm eight-hole miniplate. Each group was subjected to incisal or homolateral molar region loading. The load resistance values were measured at load application causing tip displacement of 1, 3, and 5 mm, and at the time at which the system achieves its maximum strength (MS). Means and standard deviations were compared among groups using analysis of variance and the Tukey test. Group 2PPL showed higher strength for all the displacements. For incisal loading, no statistically significant differences were found between groups 1SP, 3DP, and 3DPP. For molar loading, group 1SP and 3DPP showed statistically significant differences. For MS testing, group 1SP and 2PPL showed statistically significant differences in incisal loading; group 1SP and 3DP showed no statistically significant differences; and group 3DPP showed lower values of strength. Two parallel miniplates provide the most favorable mechanical behavior under the conditions tested.

Detection of effort maximality in adults performing isokinetic wrist flexion and extension

2021 ◽  
pp. 1-7
Author(s):  
Mercè Torra ◽  
Eduard Pujol ◽  
Anna Maiques ◽  
Salvador Quintana ◽  
Roser Garreta ◽  
...  
Keyword(s):  
High Velocity ◽  
Healthy Male ◽  
Wrist Flexion ◽  
Low Velocity ◽  
Wrist Extensor ◽  
Submaximal Effort ◽  
The Difference ◽  
Muscle Groups ◽  
Maximal Effort ◽  
Flexion And Extension

BACKGROUND: The difference between isokinetic eccentric to concentric strength ratios at high and low velocities (DEC) is a powerful tool for identifying submaximal effort in other muscle groups but its efficiency in terms of the wrist extensors (WE) and flexors (WF) isokinetic effort has hitherto not been studied. OBJECTIVE: The objective of the present study is to examine the usefulness of the DEC for identifying suboptimal wrist extensor and flexor isokinetic efforts. METHODS: Twenty healthy male volunteers aged 20–40 years (28.5 ± 3.2) were recruited. Participants were instructed to exert maximal and feigned efforts, using a range of motion of 20∘ in concentric (C) and eccentric (E) WE and WF modes at two velocities: 10 and 40∘/s. E/C ratios (E/CR) where then calculated and finally DEC by subtracting low velocity E/CR from high velocity ones. RESULTS: Feigned maximal effort DEC values were significantly higher than their maximal effort counterparts, both for WF and WE. For both actions, a DEC cutoff level to detect submaximal effort could be defined. The sensitivity of the DEC was 71.43% and 62.5% for WE ad WF respectively. The specificity was 100% in both cases. CONCLUSION: The DEC may be a valuable parameter for detecting feigned maximal WF and WE isokinetic effort in healthy adults.

Traumatic Brachial Plexus Palsy in Children: Long-Term Outcome and Strategy of Reconstruction

2021 ◽  
Author(s):  
Tarek A. El-Gammal ◽  
Amr El-Sayed ◽  
Mohamed M. Kotb ◽  
Waleed Riad Saleh ◽  
Yasser Farouk Ragheb ◽  
...  
Keyword(s):  
Brachial Plexus ◽  
External Rotation ◽  
Hand Function ◽  
Functional Restoration ◽  
Shoulder Abduction ◽  
Wrist Flexion ◽  
Term Outcome ◽  
Long Term Outcome ◽  
Age At Surgery ◽  
Flexion And Extension

Abstract Background Traumatic brachial plexus injuries in children represent a definite spectrum of injuries between adult and neonatal brachial plexus injuries. Their characteristics have been scarcely reported in the literature. The priority of functional restoration is not clear. Materials and Methods In total, 52 children with surgically treated traumatic brachial plexus injuries, excluding Erb's palsy, were reviewed after a minimum follow-up of 2 years. All children except nine were males, with an average age at surgery of 8 years. Forty-five children had exclusive supraclavicular plexus injuries. Twenty-one of them (46%) had two or more root avulsions. Seven children (13.5%) had infraclavicular plexus injuries. Time from trauma to surgery varied from 1 to 15 months (mean = 4.7 months). Extraplexal neurotization was the most common surgical technique used. Results Shoulder abduction and external rotation were restored to an average of 83 and 26 degrees, respectively. Elbow flexion and extension were restored to grade ≥3 in 96 and 91.5% of cases, respectively. Finger flexion and extension were restored to grade ≥4 in 29 and 32% of cases, respectively. Wrist flexion and extension were restored to grade ≥4 in 21 and 27% of cases, respectively. Results of neurotization were superior to those of neurolysis and nerve grafting. Among the 24 children with insensate hands, 20 (83.3%) recovered S3 sensation, 3 recovered S2, and 1 recovered S1. No case complained of neuropathic pain. Functional recovery correlated negatively but insignificantly with the age at surgery and time from injury to surgery. Conclusion Brachial plexus injuries in children are associated with a high incidence root avulsions and no pain. Neurotization is frequently required and the outcome is not significantly affected by the delay in surgery. In total plexus injuries, some useful hand function can be restored, and management should follow that of obstetric palsy and be focused on innervating the medial cord.

scholarly journals Joint-Specific Play Controller for Upper Extremity Therapy: Feasibility Study in Children With Wrist Impairment

2016 ◽  
Vol 96 (11) ◽  
pp. 1773-1781
Author(s):  
Bethany J. Wilcox ◽  
Megan M. Wilkins ◽  
Benjamin Basseches ◽  
Joel B. Schwartz ◽  
Karen Kerman ◽  
...  
Keyword(s):  
Upper Extremity ◽  
Computer Games ◽  
Average Frequency ◽  
Cross Sectional Study ◽  
Wrist Flexion ◽  
Motor Impairments ◽  
Cross Sectional ◽  
Play Activity ◽  
Play Session ◽  
Flexion And Extension

Abstract Background Challenges with any therapeutic program for children include the level of the child's engagement or adherence. Capitalizing on one of the primary learning avenues of children, play, the approach described in this article is to develop therapeutic toy and game controllers that require specific and repetitive joint movements to trigger toy/game activation. Objective The goal of this study was to evaluate a specially designed wrist flexion and extension play controller in a cohort of children with upper extremity motor impairments (UEMIs). The aim was to understand the relationship among controller play activity, measures of wrist and forearm range of motion (ROM) and spasticity, and ratings of fun and difficulty. Design This was a cross-sectional study of 21 children (12 male, 9 female; 4–12 years of age) with UEMIs. Methods All children participated in a structured in-clinic play session during which measurements of spasticity and ROM were collected. The children were fitted with the controller and played with 2 toys and 2 computer games for 5 minutes each. Wrist flexion and extension motion during play was recorded and analyzed. In addition, children rated the fun and difficulty of play. Results Flexion and extension goal movements were repeatedly achieved by children during the play session at an average frequency of 0.27 Hz. At this frequency, 15 minutes of play per day would result in approximately 1,700 targeted joint motions per week. Play activity was associated with ROM measures, specifically supination, but toy perception ratings of enjoyment and difficulty were not correlated with clinical measures. Limitations The reported results may not be representative of children with more severe UEMIs. Conclusions These outcomes indicate that the therapeutic controllers elicited repetitive goal movements and were adaptable, enjoyable, and challenging for children of varying ages and UEMIs.

Biomechanical Comparison of Five Different Atlantoaxial Posterior Fixation Techniques

Spine ◽  
2000 ◽  
Vol 25 (22) ◽  
pp. 2877-2883 ◽  
Author(s):  
Thomas Henriques ◽  
Bryan W. Cunningham ◽  
Claes Olerud ◽  
Norimichi Shimamoto ◽  
Guy A. Lee ◽  
...  
Keyword(s):  
Posterior Fixation ◽  
Fixation Techniques ◽  
Biomechanical Comparison

Assessment of Muscle Activity and Joint Angles in Small-Handed Pianists: A Pilot Study on the 7/8-Sized Keyboard versus the Full-Sized Keyboard

2006 ◽  
Vol 21 (1) ◽  
pp. 3-9
Author(s):  
B G Wristen ◽  
M C Jung ◽  
A K G Wismer ◽  
M S Hallbeck
Keyword(s):  
Pilot Study ◽  
Research Question ◽  
Wrist Flexion ◽  
Joint Angles ◽  
Ulnar Deviation ◽  
Surface Electrodes ◽  
Musical Excerpt ◽  
Muscle Loading ◽  
Maximal Angle ◽  
Flexion And Extension

This pilot study examined whether the use of a 7/8 keyboard contributed to the physical ease of small-handed pianists as compared with the conventional piano keyboard. A secondary research question focused on the progression of physical ease in pianists making the transition from one keyboard to the other. For the purposes of this study, a hand span of 8 inches or less was used to define a “small-handed” pianist. The goal was to measure muscle loading and hand span during performance of a specified musical excerpt. For data collection, each of the two participants was connected to an 8-channel electromyography system via surface electrodes, which were attached to the upper back/shoulder, parts of the hand and arm, and masseter muscle of the jaw. Subjects also were fitted with electrogoniometers to capture how the span from the first metacarpophalangeal (MCP) joint to the fifth MCP joint moves according to performance demands, as well as wrist flexion and extension and radial and ulnar deviation. We found that small-handed pianists preferred the smaller keyboard and were able to transition between it and the conventional keyboard. The maximal angle of hand span while playing a difficult piece was about 5º smaller radially and 10º smaller ulnarly for the 7/8 keyboard, leading to perceived ease and better performance as rated by the pianists.

scholarly journals The surface electromyography analysis of the non-plegic upper limb of hemiplegic subjects

2010 ◽  
Vol 68 (4) ◽  
pp. 562-566 ◽  
Author(s):  
Heloyse U Kuriki ◽  
Raquel N. de Azevedo ◽  
Augusto C. de Carvalho ◽  
Fábio Mícolis de Azevedo ◽  
Rúben F Negrão-Filho ◽  
...  
Keyword(s):  
Control Group ◽  
Electromyographic Activity ◽  
Healthy Individuals ◽  
Wrist Flexion ◽  
Functional Changes ◽  
Normal Individuals ◽  
Flexor Muscles ◽  
Stroke Group ◽  
Dominant Member ◽  
Flexion And Extension

Many authors have studied physical and functional changes in individuals post-stroke, but there are few studies that assess changes in the non-plegic side of hemiplegic subjects. This study aimed to compare the electromyographic activity in the forearm muscles of spastic patients and clinically healthy individuals, to determine if there is difference between the non-plegic side of hemiplegics and the dominant member of normal individuals. 22 hemiplegic subjects and 15 clinically healthy subjects were submitted to electromyography of the flexor and extensor carpi ulnaris muscles during wrist flexion and extension. The flexor muscles activation of stroke group (average 464.6 u.n) was significantly higher than the same muscles in control group (mean: 106.3 u.n.) during the wrist flexion, what shows that the non affected side does not present activation in the standart of normality found in the control group.

scholarly journals Thermoelastic coupling vibration and stability analysis of rotating circular plate in friction clutch

2018 ◽  
Vol 38 (2) ◽  
pp. 558-573 ◽  
Author(s):  
Yongqiang Yang ◽  
Zhongmin Wang ◽  
Yongqin Wang
Keyword(s):  
Differential Equation ◽  
Boundary Conditions ◽  
Circular Plate ◽  
Coupling Coefficient ◽  
Inertial Force ◽  
Angular Speed ◽  
Circular Plates ◽  
Thermoelastic Coupling ◽  
Coupling Vibration ◽  
Friction Clutch

Rotating friction circular plates are the main components of a friction clutch. The vibration and temperature field of these friction circular plates in high speed affect the clutch operation. This study investigates the thermoelastic coupling vibration and stability of rotating friction circular plates. Firstly, based on the middle internal forces resulting from the action of normal inertial force, the differential equation of transverse vibration with variable coefficients for an axisymmetric rotating circular plate is established by thin plate theory and thermal conduction equation considering deformation effect. Secondly, the differential equation of vibration and corresponding boundary conditions are discretized by the differential quadrature method. Meanwhile, the thermoelastic coupling transverse vibrations with three different boundary conditions are calculated. In this case, the change curve of the first two-order dimensionless complex frequencies of the rotating circular plate with the dimensionless angular speed and thermoelastic coupling coefficient are analyzed. The effects of the critical dimensionless thermoelastic coupling coefficient and the critical angular speed on the stability of the rotating circular plate with simply supported and clamped edges are discussed. Finally, the relation between the critical divergence speed and the dimensionless thermoelastic coupling coefficient is obtained. The results provide the theoretical basis for optimizing the structure and improving the dynamic stability of friction clutches.

The Method of Finite Differences in Solutions Concerning Circular Plate

2011 ◽  
Vol 490 ◽  
pp. 305-311
Author(s):  
Henryk G. Sabiniak
Keyword(s):  
Circular Plate ◽  
Finite Differences ◽  
Machine Building ◽  
Polar Coordinates ◽  
Circular Plates ◽  
Technical Problems ◽  
Theory Of Plates ◽  
Worm Gearing ◽  
Mixed Derivatives ◽  
Plate Deflection

Finite difference method in solving classic problems in theory of plates is considered a standard one [1], [2], [3], [4]. The above refers mainly to solutions in right-angle coordinates. For circular plates, for which the use of polar coordinates is the best option, the question of classic plate deflection gets complicated. In accordance with mathematical rules the passage from partial differentials to final differences seems firm. Still final formulas both for the equation (1), as well as for border conditions of circular plate obtained in this study and in the study [3] differ considerably. The paper describes in detail necessary mathematical calculations. The final results are presented in identical form as in the study [3]. Difference of results as well as the length of arm in passage from partial differentials to finite differences for mixed derivatives are discussed. Generalizations resulting from these discussions are presented. This preliminary proceeding has the purpose of searching for solutions to technical problems in machine building and construction, in particular finding a solution to the question of distribution of load along contact line in worm gearing.

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