bluuebunny/crossref_metadata_2025 huggingface dataset:
Roll and Pitch Motion Analysis of a Biologically Inspired Quadruped Water Runner Robot
Authors: Hyun Soo Park  , Floyd Steven , Sitti Metin
Published: December 2009

In this paper, the roll and pitch dynamics of a biologically inspired quadruped water runner robot are analyzed, and a stable robot design is proposed and tested. The robot’s foot—water interaction force is derived using drag equations. Roll direction instability is attributed to a small roll moment of inertia and large instantaneous roll moments generated by the foot—water interaction forces. Roll dynamics are modeled by approximating the water as a linear spring. Using this model, estimates on the roll moment of inertia that can endure moments generated by water interactions are derived. Instability in the pitch direction is caused by the thrust force the four feet exert on the water. To correct this, a circular tail which can negate the pitch moment around the center of mass is proposed. Both passive and active tail designs which can cope with disturbances are introduced. Based on these analyses, a stable water runner is designed, and built. Experimental high-speed video footage demonstrates the stable roll and pitch motion of the robot. Simulations are used to estimate robustness against disturbances, waves, and leg running frequency variations. It is found that roll motion is more sensitive to disturbances when compared with the pitch direction.
Multi-modal Semantic Place Classification
Authors: Pronobis A. , Martínez Mozos O. , Caputo B. , Jensfelt P.
Published: December 2009

The ability to represent knowledge about space and its position therein is crucial for a mobile robot. To this end, topological and semantic descriptions are gaining popularity for augmenting purely metric space representations. In this paper we present a multi-modal place classification system that allows a mobile robot to identify places and recognize semantic categories in an indoor environment. The system effectively utilizes information from different robotic sensors by fusing multiple visual cues and laser range data. This is achieved using a high-level cue integration scheme based on a Support Vector Machine (SVM) that learns how to optimally combine and weight each cue. Our multi-modal place classification approach can be used to obtain a real-time semantic space labeling system which integrates information over time and space. We perform an extensive experimental evaluation of the method for two different platforms and environments, on a realistic off-line database and in a live experiment on an autonomous robot. The results clearly demonstrate the effectiveness of our cue integration scheme and its value for robust place classification under varying conditions.
Treatment of Magnetic Resonance Imaging-Documented Isolated Grade III Lateral Collateral Ligament Injuries in National Football League Athletes
Authors: Bushnell Brandon D. , Bitting Seth S. , Crain Jana M. , Boublik Martin , Schlegel Theodore F.
Published: December 2009

Background

Isolated high-grade tears of the lateral collateral ligament (LCL) of the knee are rare, as most injuries are part of a broader pattern of damage to the posterolateral corner. Limited data exist in the literature about the ideal management of isolated LCL injuries, especially in elite-level athletes.

Hypothesis

Operative and nonoperative treatment of MRI-documented isolated grade III LCL injury can produce equal results in terms of return to play in the National Football League (NFL).

Study Design

Cohort study; Level of evidence, 3.

Methods

The NFL Injury Surveillance System was used to identify all players with lateral ligament injuries of the knee from 1994 to 2004. In addition, the medical staffs of all NFL clubs were surveyed about injuries during the same period. Nine players with MRI-documented isolated grade III LCL injuries were identified through this process. The medical staff for each respective player then completed a data questionnaire. Statistics were analyzed using 1-way analysis of variance.

Results

Four players underwent direct surgical repair of their injuries; they missed an average of 14.5 weeks of play and did not return within the same season. Five players were managed nonoperatively and missed an average of 2.0 weeks (P = .0001). Four of the 5 players in the nonoperative group returned within the same season at an average of 10 days; 1 missed the rest of the season. All 9 players were able to return to play the following season, and played for an average total of 2.8 (operative) and 4.4 (nonoperative) additional seasons (P = .253).

Conclusion

Nonoperative management of MRI-documented isolated grade III lateral collateral ligament injuries in NFL athletes results in more rapid return to play without subjecting the player to the risks of surgery, while achieving an equal likelihood of return to play at the professional level.
Correction of Posterior Shoulder Tightness is Associated with Symptom Resolution in Patients with Internal Impingement
Authors: Tyler Timothy F. , Nicholas Stephen J. , Lee Steven J. , Mullaney Michael , McHugh Malachy P.
Published: December 2009

Background

Glenohumeral internal rotation deficit (GIRD) and posterior shoulder tightness have been linked to internal impingement.

Purpose

To determine if improvements in GIRD and/or decreased posterior shoulder tightness are associated with a resolution of symptoms.

Study Design

Cohort study; Level of evidence, 3.

Methods

Passive internal rotation and external rotation (ER) range of motion (ROM) at 90° of shoulder abduction and posterior shoulder tightness (cross-chest adduction in side lying) were assessed in 22 patients with internal impingement (11 men, 11 women; age 41 ± 13 years). Treatment involved stretching and mobilization of the posterior shoulder. The Simple Shoulder Test (SST) was administered on initial evaluation and discharge. Changes in GIRD, ER ROM, and posterior shoulder tightness were compared between patients with complete resolution of symptoms versus patients with residual symptoms using independent t tests.

Results

Patients had significant GIRD (35°), loss of ER ROM (23°), and posterior shoulder tightness (35°) on initial evaluation (all P < .01). Physical therapy (7 ± 2 weeks; range, 3-12 weeks) improved GIRD (26° ± 14°; P < .01), ER ROM loss (14° ± 20°), and posterior shoulder tightness (27° ±19°). The SST improved from 5 ± 3 to 11 ± 1 (P < .01). A greater improvement in posterior shoulder tightness was seen in patients with complete resolution of symptoms (n = 12) compared with patients with residual symptoms (35° vs 18°; P < .05). Improvements in GIRD and ER ROM loss were not different between groups (GIRD, 25° vs 28°, P = .57; ER ROM, 14° vs 15°, P = .84).

Conclusion

Resolution of symptoms after physical therapy treatment for internal impingement was related to correction of posterior shoulder tightness but not correction of GIRD.
Return to Training and Playing after Posterior Ankle Arthroscopy for Posterior Impingement in Elite Professional Soccer
Authors: Calder James D. , Sexton Shaun A. , Pearce Christopher J.
Published: December 2009

Background

Posterior ankle impingement syndrome (PAIS) was first described in ballet dancers but is increasingly being diagnosed in other sports. Operative treatment may be indicated when nonoperative measures have failed. Traditionally, operative treatment has involved an open approach; more recently, posterior ankle arthroscopy has been employed.

Purpose

This study was conducted to describe the factors that influence return to play in professional athletes after posterior ankle arthroscopy for posterior ankle impingement syndrome.

Study Design

Case series; Level of evidence 4.

Methods

A consecutive series of 28 elite professional soccer players who had clinically and radiologically diagnosed posterior ankle impingement syndrome that failed to respond to nonoperative treatment underwent posterior ankle arthroscopy for bony or soft tissue posterior ankle impingement syndrome over 5 years.

Results

Of the 28 players, 27 were available for follow-up. Five had a diagnosis of soft tissue impingement and underwent debridement with flexor hallucis longus release, 13 had a symptomatic os trigonum that was excised arthroscopically, and 9 had removal of a bony avulsion fragment from the posterior ankle ligament complex. The mean length of time to return to training postoperatively was 34 days and return to playing was 41 days (range, 29-72 days). The duration of symptoms before surgery and excision of bony impingement were significantly correlated with the time to return to training and playing. There were no major complications and no reoperations at an average of 23 months of follow-up (range, 15-49 months).

Conclusion

Posterior ankle arthroscopy is safe and effective in the treatment of posterior ankle impingement syndrome in the elite soccer player, with return to training expected at an average of 5 weeks.
Arthroscopic Labral Repair and Treatment of Femoroacetabular Impingement in Professional Hockey Players
Authors: Philippon Marc J. , Weiss Douglass R. , Kuppersmith David A. , Briggs Karen K. , Hay Connor J.
Published: December 2009

Background

Hip injuries are common among professional hockey players in the National Hockey League (NHL).

Hypothesis

Professional hockey players will return to a high level of function and ice hockey after arthroscopic labral repair and treatment of femoroacetabular impingement.

Study Design

Case series; Level of evidence, 4.

Methods

Twenty-eight professional hockey players (NHL) were unable to perform at the professional level due to unremitting and debilitating hip pain. Players underwent arthroscopic labral repair and were treated for femoroacetabular impingement from March 2005 to December 2007. Players who had bilateral hip symptoms were excluded. Athletes completed the Modified Harris Hip Score preoperatively and postoperatively and also completed a patient satisfaction questionnaire postoperatively. Return to sport was defined as the player resuming skating for training or participation in the sport of ice hockey.

Results

The average age at the time of surgery was 27 years (range, 18-37). There were 11 left hips and 17 right hips. Player positions included 9 defensemen, 12 offensive players, and 7 goaltenders. All players had labral lesions that required repair. In addition, all patients had evidence of femoroacetabular impingement at the time of surgery. The average time to return to skating/hockey drills was 3.4 months. The average time to follow-up was 24 months (range, 12-42). The Modified Harris Hip Score improved from 70 (range, 57-100) preoperatively to an average of 95 (range, 74-100) at follow-up. The median patient satisfaction was 10 (range, 5-10). Two players had reinjury and required additional hip arthroscopy.

Conclusion

Treatment of femoroacetabular impingement and labral lesions in professional hockey players resulted in successful outcomes, with high patient satisfaction and prompt return to sport.
Cell Carriers as the Next Generation of Cell Therapy for Cartilage Repair
Authors: Brittberg Mats
Published: December 2009

Background: Since the first patient was implanted with autologous cultured chondrocytes more than 20 years ago, new variations of cell therapies for cartilage repair have appeared. Autologous chondrocyte implantation, a first-generation cell therapy, uses suspended autologous cultured chondrocytes in combination with a periosteal patch. Collagen-covered autologous cultured chondrocyte implantation, a second-generation cell therapy, uses suspended cultured chondrocytes with a collagen type I/III membrane. Today’s demand for transarthroscopic procedures has resulted in the development of third-generation cell therapies that deliver autologous cultured chondrocytes using cell carriers or cell-seeded scaffolds.

Purpose: To review the current evidence of the matrix-induced autologous chondrocyte implantation procedure, the most widely used carrier system to date. Also discussed are the characteristics of type I/III collagen membranes, behavior of cells associated with the membrane, surgical technique, rehabilitation, clinical outcomes, and quality of repair tissue.

Study Design: Systematic review.

Methods: Relevant publications were identified by searching Medline from its inception (1949) to December 2007; peer-reviewed publications of preclinical and clinical cell behavior, manufacturing process, surgical technique, and rehabilitation protocols were identified. Preclinical and clinical studies were included if they contained primary data and used a type I/III collagen membrane.

Results: Data from these studies demonstrate that patients treated with matrix-induced autologous chondrocyte implantation have an overall improvement in clinical outcomes. Reduced visual analog scale pain levels (range, 1.7-5.32 points) and improvements in the modified Cincinnati (range, 3.8-34.2 points), Lysholm-Gillquist (range, 23.09-47.6 points), Tegner-Lysholm (range, 1.39-3.9 points), and International Knee Documentation Classification scale ( P <.05) were observed. Patients had good-quality (hyaline-like) repair tissue as assessed by arthroscopic evaluation (including International Cartilage Repair Society score), magnetic resonance imaging, and histology, as well as a low incidence of postoperative complications.

Conclusion: The findings suggest that matrix-induced autologous chondrocyte implantation is a promising third-generation cell therapy for the repair of symptomatic, full-thickness articular cartilage defects.
Midterm Outcomes after Meniscal Allograft Transplantation
Authors: Lee Dae-Hee , Kim Sang-Beom , Kim Tae-Ho , Cha Eun-Jong , Bin Seong-Il
Published: December 2009

Background

Although graft extrusion is of concern after meniscal allograft transplantation (MAT), the correlation between extrusion and clinicoradiological outcomes remains unclear.

Hypothesis

Patients with graft extrusion after MAT have worse clinical outcomes and greater arthritic change than those without graft extrusion.

Study Design

Cohort study; Level of evidence, 3.

Methods

Forty-three patients underwent MAT between 1999 and 2004. Grafts were classified as either nonextruded (<3 mm) or extruded (≥3 mm) according to 1-year postoperative magnetic resonance imaging (MRI) findings. The mean patient age at the time of surgery was 33.5 years (range, 17-43 years), and the mean follow-up period was 5.1 years (range, 3.5-8.3 years). The Lysholm score was used to evaluate knee function. In addition, preoperative and postoperative (final follow-up) measurements were taken to determine the absolute and relative (affected side/normal side) joint space width (JSW) on a standing 45° flexion posteroanterior view.

Results

Magnetic resonance imaging at 1 year showed the mean graft subluxation was 3.03 ± 0.872 mm across all patients. Twenty-six knees (60%) were classified as nonextruded and 17 (40%) as extruded. No statistical difference was found between these 2 groups regarding Lysholm score improvement after MAT. Overall, absolute and relative JSWs were slightly narrower postoperatively compared with preoperatively across all patients (mean absolute difference, 0.283 mm; mean relative difference; 4.79%; P < .001). However, extruded and nonextruded knees were similar in terms of absolute (P = .764) and relative (P = .482) JSW after MAT. The amount of extrusion did not correlate with Lysholm score or the relative difference between preoperative and postoperative JSW across all patients or in either group.

Conclusion

Joint space width was slightly narrower after MAT. Extrusion had no effect on 5-year clinical or radiological outcomes.
The Effect of Rotator Cuff Tears on Surgical Outcomes after Type II Superior Labrum Anterior Posterior Tears in Patients Younger than 50 Years
Authors: Levy Howard J. , Schachter Aaron K. , Hurd Jason L. , Lassen Brett , Panagopoulos Georgia
Published: December 2009

Background

Rotator cuff injury in the setting of type II superior labrum anterior posterior lesions is a common finding. Although predictable surgical outcomes can be expected after type II superior labrum anterior posterior repair, the effect of rotator cuff tears on surgical outcome is unknown.

Hypothesis

Rotator cuff tears will not negatively affect surgical outcome of type II superior labrum anterior posterior repairs.

Study Design

Cohort study; Level of evidence, 3.

Methods

The study group included 93 patients younger than 50 years who underwent arthroscopic type II superior labrum anterior posterior repair and were available for review at a minimum of 2 years after surgery. Group 1 patients were identified as having normal rotator cuffs at the time of repair. Group 2 patients were identified as having rotator cuff injury at the time of repair (either partial-thickness or full-thickness tears). Statistical analysis was performed comparing the postoperative University of California, Los Angeles shoulder scores and overall improvement in University of California, Los Angeles score using the Student t test for significance.

Results

Mean follow-up was 2.54 years; 52.7% of patients had evidence of rotator cuff tears at the time of surgery. The mean postoperative University of California, Los Angeles score for group 1 was 32.9 (improvement of 11.0), and the mean postoperative University of California, Los Angeles score for group 2 was 33.3 (improvement of 12.2). There was not a significant difference in any of the outcome measures between groups.

Conclusion

Predictable short-term surgical results and return to activity can be expected after repair of type II superior labrum anterior posterior lesions in patients younger than 50 years who have coexistent rotator cuff tear. Although cuff lesions did not have a negative effect on the short-term outcome in patients with type II superior labrum anterior posterior lesions, longer-term follow-up is needed to determine natural history of this pathologic condition.
Predictors of Running-Related Injuries in Novice Runners Enrolled in a Systematic Training Program
Authors: Buist Ida , Bredeweg Steef W. , Lemmink Koen A. P. M. , van Mechelen Willem , Diercks Ron L.
Published: December 2009

Background

The popularity of running is still growing. As participation increases, running-related injuries also increase. Until now, little is known about the predictors for injuries in novice runners.

Hypothesis

Predictors for running-related injuries (RRIs) will differ between male and female novice runners.

Study Design

Cohort study; Level of evidence, 2.

Methods

Participants were 532 novice runners (226 men, 306 women) preparing for a recreational 4-mile (6.7-km) running event. After completing a baseline questionnaire and undergoing an orthopaedic examination, they were followed during the training period of 13 weeks. An RRI was defined as any self-reported running-related musculoskeletal pain of the lower extremity or back causing a restriction of running for at least 1 week.

Results

Twenty-one percent of the novice runners had at least one RRI during follow-up. The multivariate adjusted Cox regression model for male participants showed that body mass index (BMI) (hazard ratio [HR], 1.15; 95% confidence interval [CI], 1.05-1.26), previous injury in the past year (HR, 2.7; 95% CI, 1.36-5.55), and previous participation in sports without axial load (HR, 2.05; 95% CI, 1.03-4.11) were associated with RRI. In female participants, only navicular drop (HR, 0.85; 95% CI, 0.75-0.97) remained a significant predictor for RRI in the multivariate Cox regression modeling. Type A behavior and range of motion (ROM) of the hip and ankle did not affect risk.

Conclusion

Male and female novice runners have different risk profiles. Higher BMI, previous injury, and previous sports participation without axial loading are important predictors for RRI in male participants. Further research is needed to detect more predictors for female novice runners.
An in Vitro Analysis of an Anatomical Medial Knee Reconstruction
Authors: Coobs Benjamin R. , Wijdicks Coen A. , Armitage Bryan M. , Spiridonov Stanislav I. , Westerhaus Benjamin D. , Johansen Steinar , Engebretsen Lars , LaPrade Robert F.
Published: December 2009

Background

An anatomical medial knee reconstruction has not been described in the literature.

Hypothesis

Knee stability and ligamentous load distribution would be restored to the native state with an anatomical medial knee reconstruction.

Study Design

Controlled laboratory study.

Methods

Ten nonpaired cadaveric knees were tested in the intact, superficial medial collateral ligament and posterior oblique ligament—sectioned, and anatomically reconstructed states. Each knee was tested at 0°, 20°, 30°, 60°, and 90° of knee flexion with a 10-N·m valgus load, 5-N·m external and internal rotation torques, and 88-N anterior and posterior drawer loads. A 6 degrees of freedom electromagnetic motion tracking system measured angulation and displacement changes of the tibia with respect to the femur. Buckle transducers measured the loads on the intact and reconstructed proximal and distal divisions of the superficial medial collateral ligament and the posterior oblique ligament.

Results

A significant increase was found in valgus angulation and external rotation after sectioning the medial knee structures at all tested knee flexion angles. This was restored after an anatomical medial knee reconstruction. The authors also found a significant increase in internal rotation at 0°, 20°, 30°, and 60° of knee flexion after sectioning the medial knee structures, which was restored after the reconstruction. A significant increase in anterior translation was observed after sectioning the medial knee structures at 20°, 30°, 60°, and 90° of knee flexion. This increase in anterior translation was restored following the reconstruction at 20° and 30° of knee flexion, but was not restored at 60° and 90°. A small, but significant, increase in posterior translation was found after sectioning the medial knee structures at 0° and 30° of knee flexion, but this was not restored after the reconstruction. Overall, there were no clinically important differences in observed load on the ligaments when comparing the intact with the reconstructed states for valgus, external and internal rotation, and anterior and posterior drawer loads.

Conclusion

An anatomical medial knee reconstruction restores near-normal stability to a knee with a complete superficial medial collateral ligament and posterior oblique ligament injury, while avoiding overconstraint of the reconstructed ligament grafts.

Clinical Significance

This anatomical medial knee reconstruction technique provides native stability and ligament load distribution in patients with chronic or severe acute medial knee injuries.
Comparative Kinematic Evaluation of All-Inside Single-Bundle and Double-Bundle Anterior Cruciate Ligament Reconstruction
Authors: Tsai Andrew G. , Wijdicks Coen A. , Walsh Michael P. , LaPrade Robert F.
Published: December 2009

Background

The efficacy of single-bundle versus double-bundle ACL reconstruction in improving knee stability has been widely discussed. The biomechanics of all-inside double-bundle ACL reconstructions have not been evaluated.

Hypothesis

An anatomic all-inside double-bundle ACL reconstruction will more effectively restore native knee kinematics in vitro, especially rotational stability, when compared with an all-inside single-bundle ACL reconstruction.

Study Design

Controlled laboratory study.

Methods

Seven pairs of fresh-frozen cadaveric human knees were used. Knees were tested using 88 N of force for anterior and posterior drawers, 5 N·m internal and external rotation moments, 10 N·m valgus and varus moments, and coupled 5 N·m internal rotation and 10 N·m valgus moments to simulate a pivot shift at 0°, 20°, 30°, 60°, and 90° of knee flexion. Motion of the knee in response to external loading was measured with a Polhemus electromagnetic tracking system. Knees were first tested in the intact state, with either the anteromedial or posterolateral bundle cut, and then with both bundles cut. Subsequently, 7 single-bundle and 7 double-bundle all-inside ACL reconstructions were performed.

Results

Both single- and double-bundle all-inside ACL reconstructions restored knee kinematics for posterior drawer, varus/valgus rotation, and internal/external rotation motions. After single-bundle all-inside ACL reconstruction, anterior translation during the simulated pivot-shift test was significantly higher compared with the intact state at 20°, 30°, and 60° of flexion. There was no significant difference between the double-bundle all-inside ACL reconstruction and the intact knee during a simulated pivot shift.

Conclusion

We found that an all-inside double-bundle ACL reconstruction demonstrated significant improvement in restoring normal rotational knee motion during simulated pivot-shift testing compared with single-bundle ACL reconstructions in vitro, with no significant differences in other knee loading conditions.

Clinical Relevance

All-inside double-bundle ACL reconstruction may provide advantages over single-bundle ACL reconstruction for rotational knee stability.
Correlation of Valgus Stress Radiographs with Medial Knee Ligament Injuries
Authors: LaPrade Robert F. , Bernhardson Andrew S. , Griffith Chad J. , Macalena Jeffrey A. , Wijdicks Coen A.
Published: December 2009

Background

The amount of medial compartment opening for medial knee injuries determined by valgus stress radiography has not been well documented. The purpose of this study was to develop clinical guidelines for diagnosing medial knee injuries using valgus stress radiography.

Hypothesis

Measurements of medial compartment gapping can accurately differentiate between normal and injured medial structure knees on valgus stress radiographs.

Study Design

Controlled laboratory study.

Methods

Valgus stress radiographs were obtained on 18 adult lower extremities using 10-N·m and clinician-applied valgus loads at 0° and 20° of flexion to intact knees and after sequential sectioning of the superficial medial collateral ligament proximally and distally, the meniscofemoral and meniscotibial portions of the deep medial collateral ligament, the posterior oblique ligament, and the cruciate ligaments. Three independent observers of different experience levels measured all of the radiographs during 2 separate occasions to determine intraobserver repeatability and interobserver reproducibility.

Results

Compared with the intact knee, significant medial joint gapping increases of 1.7 mm and 3.2 mm were produced at 0° and 20° of flexion, respectively, by a clinician-applied load on an isolated grade III superficial medial collateral ligament simulated injury. A complete medial knee injury yielded gapping increases of 6.5 mm and 9.8 mm at 0° and 20°, respectively, for a clinician-applied load. Intraobserver repeatability and interobserver reproducibility intraclass correlation coefficients were .99 and .98, respectively.

Conclusion

Valgus stress radiographs accurately and reliably measure medial compartment gapping but cannot definitively differentiate between meniscofemoral- and meniscotibial-based injuries. A grade III medial collateral ligament injury should be suspected with greater than 3.2 mm of medial compartment gapping compared to the contralateral knee at 20° of flexion, and this injury will also result in gapping in full extension.

Clinical Significance

Valgus stress radiographs provide objective and reproducible measurements of medial compartment gapping, which should prove useful for definitive diagnosis, management, and postoperative follow-up of patients with medial knee injuries.
Effect of Posteroinferior Capsule Tightness on Contact Pressure and Area beneath the Coracoacromial Arch during Pitching Motion
Authors: Muraki Takayuki , Yamamoto Nobuyuki , Zhao Kristin D. , Sperling John W. , Steinmann Scott P. , Cofield Robert H. , An Kai-Nan
Published: December 2009

Background

Tightness of the posteroinferior capsule is assumed to be the cause of internal rotation loss in baseball pitchers. Although the relationship between posterior capsule and subacromial impingement has been recognized, this relationship during the baseball-pitching motion is unclear.

Hypothesis

Contact pressure during baseball-pitching motion increases with posterior capsule tightness.

Study Design

Controlled laboratory study.

Methods

Eight fresh-frozen shoulders were used. The peak contact pressure and area on the coracoacromial arch were measured on a custom-designed shoulder experimental device capable of 6 degrees of freedom motion. Simultaneously, the sites of peak pressure on the coracoacromial arch and humerus were observed from various angles. The posteroinferior capsule tightness was simulated by plicating the capsule in the region from 6 to 8 o'clock. The static testing positions correlated to the early cocking, late cocking, acceleration, deceleration, and follow-through phases of the pitching motion.

Results

The peak contact pressure during the follow-through phase (0.63 ± 0.50 MPa) significantly increased with posteroinferior capsule tightness (1.00 ± 0.65 MPa) (P = .014). Additionally, the contact area on the coracoacromial ligament during the follow-through phase (0.98 ± 0.67 cm2) significantly increased with posteroinferior capsule tightness (1.47 ± 0.91 cm 2) (P < .001). The site of the peak contact pressure did not change between the 2 conditions.

Conclusion

Our findings demonstrate that posteroinferior capsule tightness leads to higher contact pressure under the subacromial arch and increased contact area, particularly on the coracoacromial ligament during the follow-through phase.

Clinical Relevance

This tightness may affect risk of injury of the rotator cuff and its surrounding tissues by increasing subacromial contact during pitching.
Reconstruction of the Medial Patellofemoral Ligament for Treatment of Patellofemoral Instability: A Systematic Review
Authors: Buckens Constantinus F. M. , Saris Daniël B. F.
Published: December 2009

Background

Growing awareness of the biomechanical contribution of the medial patellofemoral ligament has led to an upsurge in the publication of techniques and trials dealing with reconstructive techniques, warranting a review that includes the most recent evidence.

Study Design

Systematic review.

Methods

The authors undertook a systematic electronic search and rigorous screening process to find and identify published evidence describing the outcomes of medial patellofemoral ligament reconstruction.

Results

Fourteen trials were included for analysis. Although they showed generally excellent outcomes for medial patellofemoral ligament reconstruction modalities, there were several recurring weaknesses. Most were small case series, many had limited follow-up, and a majority employed other adjunctive techniques besides medial patellofemoral ligament reconstruction, making it difficult to distinguish the determining factors in their outcomes.

Conclusion

There is limited but growing evidence that a medial patellofemoral ligament—based surgical approach to patellofemoral instability leads to excellent functional outcomes.
Physical Scale Modeling of Smoke Contamination in Upper Balconies by a Channeled Balcony Spill Plume in an Atrium
Authors: Tan F. , Harrison R. , Spearpoint M.J.
Published: December 2009

Whether the balcony spill plume will rise unhindered as a free plume or curl inward and interact with the atrium structure is dependent upon a number of factors. Not all the factors are well investigated and wholly understood, resulting in limited guidance for fire engineers. This article systematically investigates the effects of varying balcony breadths, plume widths, and fire sizes on smoke contamination in upper balconies through a series of smoke flow experiments conducted using a one-tenth physical scale model representing a six-story atrium building. The scale model simulated a fire in an adjacent compartment connecting to a fully open atrium. Visual observations and temperature measurements of the smoke flows were carried out. From the results, it was established that the extent of smoke contamination in upper balconies increased with decreasing balcony breadths, increasing plume widths, and decreasing fire sizes. Analysis showed that the aspect ratio of plume width to balcony breadth can be used to determine whether smoke contamination of upper balconies will occur. Where contamination is likely, an empirical correlation was developed to determine the minimum height of contamination above the lowest balcony of smoke contamination.
Effect of Different Fuels on Confined Compartment Fire
Authors: Songyang Li  , Ruowen Zong  , Lvyi Chen  , Tao Wei  , Guangxuan Liao
Published: December 2009

Experimental simulations of confined compartment fires are conducted in a reduced-scale compartment. Different areas of fire source and different types of fuel are considered in order to investigate the fire growth process and critical condition for flashover according to the changeable fire source characteristics. For these experimental cases, profiles of mean upper layer temperatures and temperature fluctuations are measured. The mass flow rate out from two vents is extensively discussed. A dimensionless model of this compartment fire growth is developed based on the nonlinear dynamics model. The critical criterion for flashover to occur is revised later, which shows that the energy gain rate and loss rate intersect at the turning point of fuel controlled fire and ventilation controlled fire. Finally, the simulation results of the model are compared with experimental data and the critical boundary between flashover and nonflashover is illustrated to show that the theoretical prediction reasonably agreed with experimental results except for polyethylene, where a higher value of fuel property number, δ, existed.
Special Education
Authors: Fish Wade W. , Stephens Tammy L.
Published: December 2009

This study identified factors that contributed toward the decision of 57 special educators from one metropolitan region of a southwestern state to initially pursue special education careers in addition to influences that contributed toward their decision to remain on the special education career path. Participants surveyed also provided recommendations that school districts could take to effectively recruit and retain special educators. Although participants surveyed responded positively that school districts took deliberate efforts to effectively recruit special educators, perceptions regarding special educator retention efforts were less favorable. Measures to be taken by school districts to retain special educators, as recommended by those surveyed, included providing more administrative support, increasing financial incentives, and increasing training opportunities to effectively serve students receiving special education services.
Intimate Partner Violence and the Association With HIV Risk Behaviors Among Young Men in Dar es Salaam, Tanzania
Authors: Maman Suzanne , Yamanis Thespina , Kouyoumdjian Fiona , Watt Melissa , Mbwambo Jessie
Published: December 2009

There is growing evidence of the association between gender-based violence and HIV from the perspective and experiences of women. The purpose of this study is to examine these associations from the perspective of young men living in Dar es Salaam, Tanzania. A community-based sample of 951 men were interviewed, of whom 360 had sex in the past 6 months and were included in these analyses. Almost a third of the men (29.2%) reported that they had been physically violent at least once with an intimate partner. Men who reported more lifetime sexual partners (OR = 8.75; 95% CI = 2.65, 28.92), experienced physical violence as a child at home (OR = 1.73; 95% CI = 1.09, 2.76), and were more educated (OR = 1.91; 95% CI = 1.18, 3.11) were significantly more likely to report perpetrating violence. These associations persisted after adjusting for other variables. These data from the perspective of young men reinforce earlier findings from women that HIV risk and violence are occurring together in relationships of young adults. Interventions are needed to identify men at high risk for HIV and engage them in interventions that are designed to change norms and behaviors related to power and control with their sexual partners.
Commission Versus Receipt of Violence During Pregnancy: Associations With Substance Abuse Variables
Authors: Tzilos Golfo K. , Grekin Emily R. , Beatty Jessica R. , Chase Sara K. , Ondersma Steven J.
Published: December 2009

The tendency for women to report both commission and receipt of violence is an understudied phenomenon. In particular, little is known about individual differences as a function of commission vs. receipt of partner violence among pregnant women. Using a sample of 78 cohabiting low-SES pregnant women, the current study examines three violence subtypes based on self-report (primarily commission of violence, primarily receipt of violence, and no report of violence) and investigated differences in a range of other risk factors among these subtypes. In this sample, 47% reported higher levels of intimate partner violence (IPV) perpetration than victimization; 14% reported more IPV victimization than perpetration; and 39% reported no IPV. Results demonstrate clear differences between women reporting IPV and those not reporting IPV and clear differences between IPV subtypes in terms of partner substance use, with women reporting primarily receipt of violence also reporting more drug and alcohol abuse by their partners. Although preliminary, these findings suggest that the commission of violence may be more common during pregnancy than the receipt of violence, but that risks for these two subgroups are similar.
Intimate Partner Violence in Interracial Couples: A Comparison to White and Ethnic Minority Monoracial Couples
Authors: Fusco Rachel A.
Published: December 2009

The number of interracial couples in the U.S. is growing, but they often receive little support. Although previous studies have explored the relationship between low social support and decreased relationship satisfaction in interracial couples, there are few studies on intimate partner violence (IPV) in these couples. To better understand IPV in interracial couples compared to monoracial couples, all police-reported IPV events across a municipality were examined. Odds ratios showed differences between interracial and ethnic minority monoracial couples. Interracial couples were more likely to have a history of prior IPV (OR = 2.60), engage in mutual assault (OR = 2.36), and result in perpetrator arrest (OR = 1.71) than ethnic minority monoracial couples. Victims of IPV in interracial couples were also more likely to be injured (OR = 1.37). There were no significant differences between the couples in terms of substance use or children present during the IPV event. Differences between IPV in interracial and White couples also emerged. Interracial couples were more likely to have children present (OR = 1.84), to have a prior report (OR = 1.98), to result in victim injury (OR = 1.73), and to result in perpetrator arrest than White couples (OR = 2.18). Interracial couples were more likely to engage in mutual assault than White couples (OR = 2.94). However, interracial couples were about 50% less likely than White couples to use drugs or alcohol before or during the IPV event. Research is needed to better understand the unique challenges and needs faced by interracial couples to help them sustain healthy partnerships.
Endothelial nitric oxide synthase and nicotinamide adenosine dinucleotide phosphate oxidase p22phox gene (C242T) polymorphisms and systemic lupus erythematosus in a Chinese Population
Authors: Tang F-Y. , Xie X-W. , Ling G-H. , Liu F-Y.
Published: December 2009

Genetic polymorphisms in the endothelial nitric oxide synthase (eNOS) and nicotinamide adenosine dinucleotide phosphate (NADPH) oxidase p22phox are linked with the expression and/or progression of vascular disease. We hypothesized that these polymorphisms may influence the development and/or progression of systemic lupus erythematosus (SLE), given their linkage with vascular disease. DNA from patients with SLE (n = 90) and their age- and sex-matched controls (n = 86) from The Second Xiangya Hospital of Central South University was assessed for eNOS and NADPH oxidase p22phox polymorphisms. These polymorphisms were examined by restriction fragment length polymorphism—polymerase chain reaction. The allele frequency of the NADPH oxidase p22phox gene C242T polymorphisms significantly varied between the SLE patients and the controls. We found no association of the eNOS polymorphism with the development of renal disease. These results indicated that the etiology of patients with SLE is associated with NADPH oxidase p22phox gene C242T polymorphisms. There was no significant increased risk of SLE associated with eNOS polymorphisms in the Chinese population. Lupus (2010) 19, 192—196.
Leptin and ghrelin in Korean systemic lupus erythematosus
Authors: Kim H-A. , Choi G-S. , Jeon J-Y. , Yoon J-M. , Sung J-M. , Suh C-H.
Published: December 2009

Elevated serum leptin levels have been described in patients with systemic lupus erythematosus (SLE), however these studies have provided no information regarding the ghrelin levels. We investigated the clinical significance of serum leptin and ghrelin levels in SLE. The leptin levels of SLE patients were higher than those of normal healthy controls, while the ghrelin levels of the SLE were lower. In addition, the ghrelin levels were significantly lower in SLE patients with arthritis and hematologic disorder. Taken together, these findings suggest that leptin and ghrelin play a role in clinical manifestations observed in SLE. Lupus (2010) 19, 170—174.
Anti-CD20 therapy in patients with refractory systemic lupus erythematosus: a longitudinal analysis of 52 Hispanic patients
Authors: Garcia-Carrasco M. , Mendoza-Pinto C. , Sandoval-Cruz M. , Soto-Vega E. , Beltran-Castillo A. , Jimenez-Hernandez M. , Graillet D. , Gonzalez L. , Rojas-Rodriguez J. , Pineda-Almazana A. , Zamudio-Huerta L. , Lopez-Colombo A.
Published: December 2009

The objective of this study was to investigate the efficacy and safety of anti-CD20 treatment in Hispanic patients with refractory systemic lupus erythematosus and to determine whether baseline parameters predict disease flare. Fifty-two patients with systemic lupus erythematosus, 13 with active lupus nephritis, eight with thrombocytopenia, three with leukocytopenia, 25 with severe musculoskeletal involvement and three with skin involvement) refractory to conventional therapy were treated with anti-CD20 treatment (rituximab; MabThera®, Roche) plus ongoing immunosuppressive treatment. Disease activity was assessed monthly using the SLEDAI validated for the Mexican population with a follow-up period of 6 months. At 6 months of follow-up, significant clinical improvements were detected, with a reduction in the global SLEDAI validated for the Mexican population score. Five of the 13 patients with lupus nephritis (38.4%) had a complete renal response and five (38.4%) had a partial response. Rituximab was also effective in patients with autoimmune thrombocytopenia, inducing a significant increase in platelet counts (p = 0.012). Nineteen of 25 patients with severe musculoskeletal involvement had remission of arthritis. Only one of the three patients with skin involvement had no lesions at 6 months. Rituximab treatment also allowed a reduction of the oral prednisone dose in the majority of patients. No baseline predictors of flare were found. Treatment was discontinued after the first infusion in two patients due to serum sickness and in another due to pulmonary infection. In conclusion, the addition of rituximab to conventional immunosuppressive therapy may be an effective strategy for lupus nephritis, autoimmune thrombocytopenia and inflammatory polyarthritis in patients with refractory systemic lupus erythematosus. Lupus (2010) 19, 213—219.
The public understanding of nanotechnology in the food domain
Authors: Vandermoere Frederic , Blanchemanche Sandrine , Bieberstein Andrea , Marette Stephan , Roosen Jutta
Published: December 2009

In spite of great expectations about the potential of nanotechnology, this study shows that people are rather ambiguous and pessimistic about nanotechnology applications in the food domain. Our findings are drawn from a survey of public perceptions about nanotechnology food and nanotechnology food packaging ( N = 752). Multinomial logistic regression analyses further reveal that knowledge about food risks and nanotechnology significantly influences people’s views about nanotechnology food packaging. However, knowledge variables were unrelated to support for nanofood, suggesting that an increase in people’s knowledge might not be sufficient to bridge the gap between the excitement some business leaders in the food sector have and the restraint of the public. Additionally, opposition to nanofood was not related to the use of heuristics but to trust in governmental agencies. Furthermore, the results indicate that public perceptions of nanoscience in the food domain significantly relate to views on science, technology, and nature.
Ferrofluid-based Flow Manipulation and Locomotion Systems
Authors: Zimmermann Klaus , Zeidis Igor , Böhm Valter , Greiser Steffen , Popp Jana
Published: December 2009

The article demonstrates some examples of locomotion systems with bifluidic flow control using ferrofluid. By controlling the change of shape, position, and pressure of the ferrofluid in a secondary low viscous fluid by magnetic fields locomotion of objects or the ferrofluid itself can be realized. The locomotion of an object is caused, in the first example, by a ferrofluid generated flow of the secondary fluid and in the second and third case by the direct alteration of the ferrofluid position.
Development of a Multi-axial Mechanical Cell Stimulator
Authors: Stevenson Mathew , Waldman Stephen D. , Yongjun Lai
Published: December 2009

This article proposes a novel electro-mechanical device to facilitate the investigation of mechanical stimuli on cells. The system was designed to dynamically apply a generalized, multi-axial state of deformation to a cell-encapsulated in a hydrogel cube by applying independent combinations of normal and shear forces to the faces of the cube. The compact device was prototyped using ABS plastic and used shape memory alloy actuator wires to generate the required forces and deformations. The electro-thermal and thermo-mechanical behaviors of the actuation system were modeled analytically and the stimulator was tested to evaluate its performance. Strain amplitudes of up to 8% (tension/compression and shear) were achievable, while deforming a cube with 1 cm side length.
Analysis and Design of Hollow Helical Springs for Shape Memory Actuators
Authors: Spinella I. , Dragoni E.
Published: December 2009

Shape memory alloys (SMAs) can be exploited successfully to reduce the complexity and the weight of actuators, but the main drawbacks that limit the use of SMAs are the low bandwidth, poor energetic efficiency, and unsatisfactory stroke. This article contributes to enhancing the mechanical, thermal, and electric performances of SMA actuators by providing analysis and design equations for helical springs with hollow round section. By emptying the inefficient material from its center, the hollow section features a lower mass, lower cooling time, and lower heating energy than its solid counterpart for given strength, stiffness, and deflection. The advantages of the hollow construction over solid springs are presented and discussed by means of dimensionless functions. A step-by-step procedure leading to the optimal design of hollow springs with minimum energy consumption is finally proposed.