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Journal of Sports Sciences 2016The purpose of this study was to investigate the effect of the racket mass and the rate of strokes on the kinematics and kinetics of the trunk and the racket arm in the...
The purpose of this study was to investigate the effect of the racket mass and the rate of strokes on the kinematics and kinetics of the trunk and the racket arm in the table tennis topspin backhand. Eight male Division I collegiate table tennis players hit topspin backhands against topspin balls projected at 75 balls · min(-1) and 35 balls · min(-1) using three rackets varying in mass of 153.5, 176 and 201.5 g. A motion capture system was used to obtain trunk and racket arm motion data. The joint torques of the racket arm were determined using inverse dynamics. The racket mass did not significantly affect all the trunk and racket arm kinematics and kinetics examined except for the wrist dorsiflexion torque, which was significantly larger for the large mass racket than for the small mass racket. The racket speed at impact was significantly lower for the high ball frequency than for the low ball frequency. This was probably because pelvis and upper trunk axial rotations tended to be more restricted for the high ball frequency. The result highlights one of the advantages of playing close to the table and making the rally speed fast.
Topics: Arm; Biomechanical Phenomena; Elbow; Equipment Design; Humans; Kinetics; Male; Pelvis; Shoulder; Sports Equipment; Tennis; Time and Motion Studies; Torso; Upper Extremity; Wrist; Young Adult
PubMed: 26208598
DOI: 10.1080/02640414.2015.1069377 -
Radiography (London, England : 1995) May 2023Pelvic radiography is one of the most frequent general radiography imaging procedures. Pelvic radiography is usually performed in the supine position, but in some cases... (Randomized Controlled Trial)
Randomized Controlled Trial
INTRODUCTION
Pelvic radiography is one of the most frequent general radiography imaging procedures. Pelvic radiography is usually performed in the supine position, but in some cases erect imaging is performed. The aim of this study was to determine whether radiation dose and image quality differ between two different erect pelvic radiographic procedures in overweight and obese patients, with and without displacement of anterior adipose tissue.
METHODS
This research was a two-part study. The first part of the study was to determine a suitable fat displacement band that would not produce artifacts on the resulting radiograph when fat tissue was displaced. The second part of the study was performed in a clinical setting on 60 overweight or obese patients (BMI ≥25) referred for erect pelvic imaging. Patients were randomly divided into two equal groups, half of which displaced adipose tissue from the region of interest and the other group did not. Waist and hip circumference, height, weight, dose-area- product (DAP), primary field size, source-to-skin distance, mAs, and kV were measured. Body Mass Index (BMI), entrance surface dose (ESD), and effective dose (ED) were then calculated. The resulting images were evaluated by three radiologists.
RESULTS
It was found that a thin cotton triangular bandage produced no visible radiographic artefacts. In the group of patients using the fat displacement protocol, a statistically significant reduction in waist circumference (4.7%), DAP (38.5%), ESD (44%) and ED (38.7%) were observed (p < 0.05). In addition, a significant (p < 0.05) increase was found for all the observed image quality criteria and overall total image score with exception of sacroiliac joint, iliac crest and pubic/ischial rami.
CONCLUSION
Based on the results, the use of the adipose tissue displacement protocol for radiography of the pelvis and hip in the erect position in overweight and obese patients is recommended.
IMPLICATIONS FOR PRACTICE
The use of cotton bands to remove adipose tissue during pelvic imaging in obese and overweight patients results in a reduction of radiation dose received by the patient and improves image quality. This technique is quick, easy, and inexpensive.
Topics: Humans; Overweight; Radiation Dosage; Radiography; Obesity; Pelvis
PubMed: 36934682
DOI: 10.1016/j.radi.2023.03.004 -
Loading rate effect on tradeoff of fractures from pelvis to lumbar spine under axial impact loading.Traffic Injury Prevention 2022The transmission of impact loading from the seat-to-pelvis-to-lumbar spine in a seated occupant in automotive and military events is a mechanism for fractures to these...
The transmission of impact loading from the seat-to-pelvis-to-lumbar spine in a seated occupant in automotive and military events is a mechanism for fractures to these body regions. While postmortem human subject (PMHS) studies have replicated fractures to the pelvis or lumbar spine using isolated/component models, the role of the time factor that manifests as a loading rate issue on injuries has not been fully investigated in literature. The objective of this study was to explore the hypothesis that short duration pulses fracture the pelvis while longer pulses fracture the spine, and intermediate pulses involve both components. Unembalmed PMHS thoracolumbar spine-pelvis specimens were fixed at the superior end, and a six-axis load cell was attached. The specimens were mounted on a vertical accelerator, and noninjury and injury tests were conducted by applying short, medium, or long pulses with 5, 15, or 35 ms durations, respectively. Peak axial, shear and resultant forces were obtained. Injuries were documented using posttest x-ray and computed tomography images and scaled using the AIS (2015). The mean age, stature, weight, body mass index, and BMD of twelve specimens were 64.8 ± 11.4 years, 1.8 ± 0.01 m, 83 ± 13 kg, 26.7 ± 5.0 kg/m, and 114.5 ± 21.3 mg/cc, respectively. For the short, long, and medium duration pulses, the mean resultant forces were 5.6 ± 0.9 kN, 5.9 ± 0.94 kN, and 5.4 ± 1.8 kN, and time durations were 4.8 ± 0.5 ms, 16.3 ± 7.3 ms, and 34.5 ± 7.5 ms, respectively. For the short pulse, pelvis injuries were more severe in 3 out 4 specimens, for the medium pulse, they were distributed between the pelvis and spine, and for the long pulse, spine injuries were more severe in 3 out of 4 specimens. While acknowledging the limitations of the sample size, the results of this study support the hypothesis of the time variable in the tradeoff between pelvis and spine injuries with pulse duration. The tradeoff pattern is attributed to mass recruitment: short pulse biases injuries to pelvis while limiting spinal injuries, and the opposite is true for the longer pulse, thus supporting the hypothesis. It is important to account for the time variable in injury analysis.
Topics: Humans; Middle Aged; Aged; Accidents, Traffic; Cadaver; Lumbar Vertebrae; Spinal Injuries; Pelvis; Fractures, Bone; Biomechanical Phenomena
PubMed: 36095155
DOI: 10.1080/15389588.2022.2110589 -
Medicine Aug 2022Extrauterine leiomyoma occasionally occurs in rare locations with unusual growth patterns, especially pelvic retroperitoneal leiomyoma, which brings great challenges for...
RATIONALE
Extrauterine leiomyoma occasionally occurs in rare locations with unusual growth patterns, especially pelvic retroperitoneal leiomyoma, which brings great challenges for surgeons to make a diagnosis. It is essential to distinguish benign from malignant retroperitoneal neoplasms according to the imaging manifestations. Laparotomy and laparoscopy are the common options for pelvic retroperitoneal neoplasms, while they may cause side effects during operation such as secondary damage. Appropriate surgical techniques should be adopted to ensure the complete excision of neoplasms meanwhile preserve the urination, defecation, and sexual function.
PATIENT CONCERNS
A 30-year-old woman was referred to our hospital because of dull pain in the perianal region for 1 month. Laboratory results including tumor markers were all within normal limits. The digital rectal examination revealed a huge and tough mass with smooth mucosa protruding into the rectal cavity from the rear area of rectum.
DIAGNOSIS
Imaging examinations were performed. Contrasted computed tomography (CT) of pelvis showed an enhanced retroperitoneal solid mass in the space between sacrum and rectum, and very close to the levator ani muscle. The mass was about 11.0*8.0 cm in size. Computerized tomography angiography (CTA) showed the distal branches of bilateral internal iliac artery went into the mass. Endoscopic ultrasonography (US) showed the mass compressed the rectum, as well as a clear boundary to the rectal wall. A histopathologic examination confirmed the mass was a pelvic retroperitoneal leiomyoma.
INTERVENTIONS
The patient underwent an operative resection with da Vinci Si surgical system after routine preoperative preparation. Anorectal motility was weekly monitored postoperation. No additional adjuvant therapy was performed.
OUTCOMES
The patient could walk after 1 day and defecate normally on the third day after operation. She was discharged on the seventh postoperative day. No adverse events including pelvic floor hernia or defecation dysfunction occurred in the follow-up period. At 4 weeks follow-up, the patient was pain-free and recovered well.
LESSONS
Although imaging examinations were crucial for retroperitoneal neoplasms, histopathological examination remains the "gold standard" for making a definite diagnosis. This case highlights the possibility of retroperitoneal leiomyoma occurring in a woman of reproductive age and the advantages of robotic surgical system in pelvic retroperitoneal surgeries.
Topics: Adult; Female; Humans; Leiomyoma; Pelvic Neoplasms; Pelvis; Retroperitoneal Neoplasms; Retroperitoneal Space; Robotics
PubMed: 35945744
DOI: 10.1097/MD.0000000000029650 -
International Urology and Nephrology Jul 2022The aim of the study was to investigate whether a novel simple measurement of pelvic anatomy, the pelvic anatomical index (PAI), which is obtained from simple physical...
OBJECTIVES
The aim of the study was to investigate whether a novel simple measurement of pelvic anatomy, the pelvic anatomical index (PAI), which is obtained from simple physical examination, was predictive for potential difficulty and adverse outcome in radical prostatectomy.
MATERIALS AND METHODS
Available data from 73 consecutive radical prostatectomy patients were analyzed. The distances between umbilicus and cranial edge of the symphysis pubis (USPD) and between root of the penis and umbilicus (PUD) were measured. PAI was obtained using the formula (PUD/USPD) × body mass index (BMI). Indicators of surgical difficulty assessed were operation time (OT), dorsal vein bleeding (DVB), total blood loss (TBL), and surgical margin (SM) status. Patients with below-median values of the OT, DVB, TBL, and had negative SM were grouped as favorable surgery (n = 18).
RESULTS
Median OT, DVB, and TBL were 215 (IQR: 187.5-240) min, 380 (IQR: 200-500) cc, and 1000 (IQR: 700-1300) cc, respectively. Both PAI and BMI were significantly correlated with TBL, DVB, and OT (p < 0.05, for all). PAI and BMI significantly associated with favorable surgery (p = 0,006 and p = 0.048, respectively). However, only PAI was an independent predictor of favorable surgery in multivariable logistic regression analysis. A PAI 36 kg/m was determined as the threshold value for favorable surgery with 83.3% sensitivity and 60% specificity.
CONCLUSION
PAI significantly correlated with almost all surgical parameters and was a significant independent predictor of favorable surgery. PAI can enable the physician to select and discuss individualized treatment options for patients during preoperative planning.
Topics: Body Mass Index; Humans; Male; Operative Time; Pelvis; Prostate; Prostatectomy
PubMed: 35438411
DOI: 10.1007/s11255-022-03206-4 -
Journal of Biomechanical Engineering Feb 2024In recent conflicts, blast injury from landmines and improvised explosive devices (IEDs) has been the main mechanism of wounding and death. When a landmine or IED...
In recent conflicts, blast injury from landmines and improvised explosive devices (IEDs) has been the main mechanism of wounding and death. When a landmine or IED detonates under a vehicle (an under-body blast), the seat acceleration rapidly transmits a high load to the pelvis of the occupants, resulting in torso and pelvic injury. Pelvic fractures have high mortality rates, yet their injury mechanism has been poorly researched. Three (3) fresh-frozen male pelvic specimens were tested under axial impact loading. The pelvis was impacted mounted upside down by dropping a 12 kg mass at target impact velocities ranging from 1 to 8.6 m/s with time to peak velocity ranging from 3.8 to 5.8 ms. Resulting fractures were broadly categorized as involving a bilateral pubis rami fracture, a bilateral ischium fracture, and sacroiliac joint disruption. The study provides insights into the type and severity of pelvic injury that may occur over a range of under-body blast (UBB)-relevant loading profiles.
Topics: Male; Humans; Explosions; Pelvis; Blast Injuries; Sacroiliac Joint; Weight-Bearing; Fractures, Bone
PubMed: 38071487
DOI: 10.1115/1.4064214 -
Diseases of the Colon and Rectum Aug 2018A 63-year-old man presents to his primary care doctor with a one-month history of blood in his stools. He is referred for a colonoscopy and found to have a friable mass...
A 63-year-old man presents to his primary care doctor with a one-month history of blood in his stools. He is referred for a colonoscopy and found to have a friable mass along the anterior wall just proximal to the second rectal fold. A biopsy confirms moderately-differentiated adenocarcinoma. The patient then obtains pelvic magnetic resonance imaging and chest, abdomen, and pelvis computed tomography demonstrating local invasion of the primary tumor into the mesorectal fat (T3), no suspicious regional lymph nodes (N0), and no evidence of distant metastatic disease (M0).
Topics: Adenocarcinoma; Biopsy; Clinical Decision-Making; Colonoscopy; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Neoadjuvant Therapy; Neoplasm Invasiveness; Neoplasm Staging; Patient Care Management; Patient Selection; Pelvis; Rectal Neoplasms; Rectum; Tomography, X-Ray Computed
PubMed: 29994956
DOI: 10.1097/DCR.0000000000001139 -
Medical & Biological Engineering &... Aug 2023High-quality gynecologist and midwife training is particularly relevant to limit medical complications and reduce maternal and fetal morbimortalities. Physical and...
High-quality gynecologist and midwife training is particularly relevant to limit medical complications and reduce maternal and fetal morbimortalities. Physical and virtual training simulators have been developed. However, physical simulators offer a simplified model and limited visualization of the childbirth process, while virtual simulators still lack a realistic interactive system and are generally limited to imposed predefined gestures. Objective performance assessment based on the simulation numerical outcomes is still not at hand. In the present work, we developed a virtual childbirth simulator based on the Mixed-Reality (MR) technology coupled with HyperMSM (Hyperelastic Mass-Spring Model) formulation for real-time soft-tissue deformations, providing intuitive user interaction with the virtual physical model and a quantitative assessment to enhance the trainee's gestures. Microsoft HoloLens 2 was used and the MR simulator was developed including a complete holographic obstetric model. A maternal pelvis system model of a pregnant woman (including the pelvis bone, the pelvic floor muscles, the birth canal, the uterus, and the fetus) was generated, and HyperMSM formulation was applied to simulate the soft tissue deformations. To induce realistic reactions to free gestures, the virtual replicas of the user's detected hands were introduced into the physical simulation and were associated with a contact model between the hands and the HyperMSM models. The gesture of pulling any part of the virtual models with two hands was also implemented. Two labor scenarios were implemented within the MR childbirth simulator: physiological labor and forceps-assisted labor. A scoring system for the performance assessment was included based on real-time biofeedback. As results, our developed MR simulation application was developed in real-time with a refresh rate of 30-50 FPS on the HoloLens device. HyperMSM model was validated using FE outcomes: high correlation coefficients of [0.97-0.99] and weighted root mean square relative errors of 9.8% and 8.3% were obtained for the soft tissue displacement and energy density respectively. Experimental tests showed that the implemented free-user interaction system allows to apply the correct maneuvers (in particular the "Viennese" maneuvers) during the labor process, and is capable to induce a truthful reaction of the model. Obtained results confirm also the possibility of using our simulation's outcomes to objectively evaluate the trainee's performance with a reduction of 39% for the perineal strain energy density and 5.6 mm for the vertical vaginal diameter when the "Viennese" technique is applied. This present study provides, for the first time, an interactive childbirth simulator with an MR immersive experience with direct free-hand interaction, real-time soft-tissue deformation feedback, and an objective performance assessment based on numerical outcomes. This offers a new perspective for enhancing next-generation training-based obstetric teaching. The used models of the maternal pelvic system and the fetus will be enhanced, and more delivery scenarios (e.g. instrumental delivery, breech delivery, shoulder dystocia) will be designed and integrated. The third stage of labor will be also investigated to include the delivery of the placenta, and the clamping and cutting of the umbilical cord.
Topics: Humans; Pregnancy; Female; Augmented Reality; Computer Simulation; Uterus; Pelvis; User-Computer Interface
PubMed: 37382859
DOI: 10.1007/s11517-023-02864-5 -
Journal of Pediatric Orthopedics 2019Surgical indications for Scheuermann kyphosis are variable. We sought to evaluate the characteristics of patients undergoing operative versus nonoperative treatment of...
BACKGROUND
Surgical indications for Scheuermann kyphosis are variable. We sought to evaluate the characteristics of patients undergoing operative versus nonoperative treatment of Scheuermann kyphosis to better understand current practices and the factors which contribute to the decision for surgical management.
METHODS
Multicenter prospective cohort study. We evaluated consecutive patients presenting with Scheuermann kyphosis. Patients underwent either surgical or nonoperative management according to surgeon and patient discretion. Preoperative patient-reported outcome measures (Scoliosis Research Society and Spinal Appearance Questionnaire scores), demographics, and radiographic characteristics were assessed.
RESULTS
Overall, 150 patients with Scheuermann kyphosis were enrolled, with 77 choosing nonoperative treatment and 73 treated operatively. Compared with the nonoperative cohort, patients treated operatively were older (16.3±2.0 vs. 15.1±2.2, P=0.0004), and had higher body mass index (26.3±7.2 vs. 22.7±6.5, P=0.003), had greater T2-T12 kyphosis (71±14 degrees vs. 61±12 degrees, P<0.001), increased pelvic incidence (46 vs. 41 degrees, P=0.03) and pelvic tilt (10 vs. 3 degrees, P=0.03). There was no detected difference in maximal sagittal Cobb angle in the operative versus nonoperative patients (73±11 vs. 70±12 degrees, P=0.11). Functionally, the operative patients had worse Scoliosis Research Society pain scores (3.7±0.9 vs. 4.1±0.7, P=0.0027) and appearance scores (2.9±0.7 vs. 3.4±0.8, P <0.0001).
CONCLUSIONS
Patients undergoing surgical management of Scheuermann disease were more likely to have large body mass index and worse pain scores. Other factors beyond radiographic measurement likely contribute to the decision for surgical management of Scheuermann kyphosis.
LEVEL OF EVIDENCE
Level II.
Topics: Adolescent; Age Factors; Body Mass Index; Female; Humans; Incidence; Kyphosis; Male; Pain; Pelvis; Retrospective Studies; Scheuermann Disease; Scoliosis; Spinal Fusion
PubMed: 30969249
DOI: 10.1097/BPO.0000000000000931 -
Gait & Posture Sep 2016Lateral hip pain during single leg loading, and hip abductor muscle weakness, are associated with gluteal tendinopathy, but it has not been shown how or whether...
BACKGROUND
Lateral hip pain during single leg loading, and hip abductor muscle weakness, are associated with gluteal tendinopathy, but it has not been shown how or whether kinematics in single leg stance differ in those with gluteal tendinopathy.
PURPOSE
To compare kinematics in preparation for, and during, single leg stance between individuals with and without gluteal tendinopathy, and the effect of hip abductor muscle strength on kinematics.
METHODS
Twenty individuals with gluteal tendinopathy and 20 age-matched pain-free controls underwent three-dimensional kinematic analysis of single leg stance and maximum isometric hip abductor strength testing. Maximum values of hip adduction, pelvic obliquity (contralateral pelvis rise/drop), lateral pelvic translation (ipsilateral/contralateral shift) and ipsilateral trunk lean during preparation for leg lift and average values in steady single leg stance, were compared between groups using an analysis of covariance, with and without anthropometric characteristics and strength as covariates.
RESULTS
Individuals with gluteal tendinopathy demonstrated greater hip adduction (standardized mean difference (SMD)=0.70, P=0.04) and ipsilateral pelvic shift (SMD=1.1, P=0.002) in preparation for leg lift, and greater hip adduction (SMD=1.2, P=0.002) and less contralateral pelvic rise (SMD=0.86, P=0.02) in steady single leg stance than controls. When including strength as a covariate, only between-group differences in lateral pelvic shift persisted (SMD=1.7, P=0.01).
CONCLUSION
Individuals with gluteal tendinopathy use different frontal plane kinematics of the hip and pelvis during single leg stance than pain-free controls. This finding is not influenced by pelvic dimension or the potentially modifiable factor of body mass index, but is by hip abductor muscle weakness.
Topics: Adult; Aged; Biomechanical Phenomena; Buttocks; Female; Humans; Male; Middle Aged; Muscle Strength; Muscle, Skeletal; Pain; Pelvic Pain; Pelvis; Tendinopathy; Walking
PubMed: 27395451
DOI: 10.1016/j.gaitpost.2016.06.020