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1.
Appl Bionics Biomech ; 2023: 8022635, 2023.
Article in English | MEDLINE | ID: mdl-36816755

ABSTRACT

Backpacks are commonly worn by many people for multiple purposes. This study investigated the effects of habitual wearing of backpacks on lower limb kinematics and kinetics. Fourteen participants were recruited for analysis. All participants performed four randomly assigned scenarios, including running and walking at speeds of 3.5 and 1.5 m/s, respectively, with and without load carriage. The motion analysis system and force plate were used to investigate the lower limb kinematics and kinetics. A paired sample t-test was performed for statistical measurement with a significance level of α = .05. The results indicated that active force, breaking force, impact peak, loading rate, active peak, maximum braking, hip flexion, and hip range of motion were substantially higher under load carriage conditions than under walking condition, however, time to peak was lower. Conversely, during load carriage running, active force, braking impulse, time to peak, ankle plantarflexion, and ankle range of motion were all higher than those during running. Carrying a backpack weighing 10% of the body weight induced different foot strike patterns at both speeds; during load carriage walking, the hip tended to flex more; whereas, during load carriage running, the ankle tended to flex more. In conclusion, human body seems to adopt different gait strategies during load carriage walking and running. That is, the hip strategy is used during walking, while the ankle strategy is used during running.

2.
Sensors (Basel) ; 22(12)2022 Jun 14.
Article in English | MEDLINE | ID: mdl-35746290

ABSTRACT

The plank is a common core-stability exercise. Developing a wearable inertial sensor system for distinguishing between acceptable and aberrant plank techniques and detecting specific deviations from acceptable plank techniques can enhance performance and prevent injury. The purpose of this study was to develop an inertial measurement unit (IMU)-based plank technique quantification system. Nineteen healthy volunteers (age: 20.5 ± 0.8 years, BMI: 22.9 ± 1.4 kg/m2) performed the standard plank technique and six deviations with five IMUs positioned on the occiput, cervical spine, thoracic spine, sacrum, and right radius to record movements. The random forest method was employed to perform the classification. The proposed binary tree classification model achieved an accuracy of more than 86%. The average sensitivities were higher than 90%, and the specificities were higher than 91%, except for one deviation (83%). These results suggest that the five IMU-based systems can classify the plank technique as acceptable or aberrant with good accuracy, high sensitivity, and acceptable specificity, which has significant implications in monitoring plank biomechanics and enabling coaching practice.


Subject(s)
Movement , Wearable Electronic Devices , Adult , Biomechanical Phenomena , Exercise , Humans , Young Adult
3.
Article in English | MEDLINE | ID: mdl-33801720

ABSTRACT

The purpose of this study was to examine the acute effect of foam rolling and vibration foam rolling on drop jump performance. The optimal time interval between warm-up using foam rolling or vibration foam rolling and drop jump performance was identified. This study included 16 male NCAA Division I college volleyball athletes. Three interventions were performed in a randomized order: the foam rolling exercise (FRE), vibration foam rolling exercise (VFRE), and static rest (control). The drop jump was performed before interventions, as well as 2 and 5 min after interventions. The FRE exhibited higher values for drop jump height (DJH) (p = 0.001; η2 = 0.382; statistical power = 0.964) and mean power generation at the hip joint (p = 0.006; η2 = 0.277; statistical power = 0.857) at 2 min compared with before intervention but not at 5 min (p > 0.05). However, the VFRE showed no significant changes in DJH (p > 0.05), and found that hippower was decreased at 5 min (p = 0.027; η2 = 0.214; statistical power = 0.680). The FRE completed in 2 min before rapid single action competition (sprint, long jump, triple jump, etc.) could increase sports performance.


Subject(s)
Athletic Performance , Warm-Up Exercise , Humans , Male , Muscle, Skeletal , Range of Motion, Articular , Vibration
4.
J Electromyogr Kinesiol ; 43: 21-27, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30179730

ABSTRACT

Clinicians frequently incorporate unstable sitting devices into training plans for improving proximal postural muscle control; however, the effect of unstable sitting conditions on postural adjustments during dynamic activities has not been fully explored. The aim of this study was to characterize early postural adjustments (EPAs) and anticipatory postural adjustments (APAs) under stable and unstable sitting conditions. Using a cross-sectional laboratory study design, 13 healthy college student volunteers used their dominant hand to reach forward and push a target under stable and unstable sitting conditions; subjects sat on an air-filled rubber cushion for the unstable condition. EPAs and APAs were quantified by recording muscle activation of the trunk and lower extremity muscles using electromyography (EMG). The center of pressure (COP) was measured using a force plate. The resulting EMG integral of the ipsilateral gastrocnemius muscle was larger during the EPA phase and smaller during the APA phase under unstable conditions (p = 0.014 and p = 0.041, respectively). COP amplitude in the anterior-posterior direction, path length, and velocity, was larger during the APA phase (p = 0.035, p = 0.023, and 0.023, respectively). This suggests greater distal muscle activation during EPAs in unstable sitting conditions, specifically in the ipsilateral gastrocnemius muscle. In addition, APAs adjusted by reducing the activity of the ipsilateral gastrocnemius muscle and increasing the anterior-posterior shift in the COP to compensate for the expected additional perturbation due to an unstable surface.


Subject(s)
Adaptation, Physiological/physiology , Anticipation, Psychological/physiology , Postural Balance/physiology , Psychomotor Performance/physiology , Sitting Position , Adolescent , Adult , Cross-Sectional Studies , Electromyography/methods , Female , Healthy Volunteers , Humans , Male , Muscle, Skeletal/physiology , Posture/physiology , Pressure , Torso/physiology , Young Adult
5.
PLoS One ; 12(7): e0181562, 2017.
Article in English | MEDLINE | ID: mdl-28727754

ABSTRACT

Functional impairment of endothelial colony-forming cells (ECFCs), a specific cell lineage of endothelial progenitor cells (EPCs) is highly associated with the severity of coronary artery disease (CAD), the most common type of cardiovascular disease (CVD). Emerging evidence show that circulating microRNAs (miRNAs) in CAD patients' body fluid hold a great potential as biomarkers. However, our knowledge of the role of circulating miRNA in regulating the function of ECFCs and the progression of CAD is still in its infancy. We showed that when ECFCs from healthy volunteers were incubated with conditioned medium or purified exosomes of cultured CAD ECFCs, the secretory factors from CAD ECFCs dysregulated migration and tube formation ability of healthy ECFCs. It is known that exosomes influence the physiology of recipient cells by introducing RNAs including miRNAs. By using small RNA sequencing (smRNA-seq), we deciphered the circulating miRNome in the plasma of healthy individual and CAD patients, and found that the plasma miRNA spectrum from CAD patients was significantly different from that of healthy control. Interestingly, smRNA-seq of both healthy and CAD ECFCs showed that twelve miRNAs that had a higher expression in the plasma of CAD patients also showed higher expression in CAD ECFCs when compared with healthy control. This result suggests that these miRNAs may be involved in the regulation of ECFC functions. For identification of potential mRNA targets of the differentially expressed miRNA in CAD patients, cDNA microarray analysis was performed to identify the angiogenesis-related genes that were down-regulated in CAD ECFCs and Pearson's correlation were used to identify miRNAs that were negatively correlated with the identified angiogenesis-related genes. RT-qPCR analysis of the five miRNAs that negatively correlated with the down-regulated angiogenesis-related genes in plasma and ECFC of CAD patients showed miR-146a-5p and miR-146b-5p up-regulation compared to healthy control. Knockdown of miR-146a-5p or miR-146b-5p in CAD ECFCs enhanced migration and tube formation activity in diseased ECFCs. Contrarily, overexpression of miR-146a-5p or miR-146b-5p in healthy ECFC repressed migration and tube formation in ECFCs. TargetScan analysis showed that miR-146a-5p and miR-146b-5p target many of the angiogenesis-related genes that were down-regulated in CAD ECFCs. Knockdown of miR-146a-5p or miR-146b-5p restores CAV1 and RHOJ levels in CAD ECFCs. Reporter assays confirmed the direct binding and repression of miR-146a-5p and miR-146b-5p to the 3'-UTR of mRNA of RHOJ, a positive regulator of angiogenic potential in endothelial cells. Consistently, RHOJ knockdown inhibited the migration and tube formation ability in ECFCs. Collectively, we discovered the dysregulation of miR-146a-5p/RHOJ and miR-146b-5p/RHOJ axis in the plasma and ECFCs of CAD patients that could be used as biomarkers or therapeutic targets for CAD and other angiogenesis-related diseases.


Subject(s)
Coronary Artery Disease/metabolism , Endothelial Cells/metabolism , Feedback, Physiological/physiology , MicroRNAs/metabolism , Biomarkers/blood , Caveolin 1/metabolism , Cell Lineage , Cell Movement/physiology , Cells, Cultured , Culture Media, Conditioned/metabolism , Endothelial Progenitor Cells/metabolism , Exosomes/metabolism , Gene Knockdown Techniques , Humans , MicroRNAs/genetics , RNA, Messenger/metabolism , rho GTP-Binding Proteins/genetics , rho GTP-Binding Proteins/metabolism
9.
Am J Emerg Med ; 32(7): 816.e1-3, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24589023

ABSTRACT

Ogilvie syndrome, also known as acute colonic pseudo-obstruction, is characterized by the clinical presentation and imaging evidence of acute colonic obstruction in the absence of a mechanical cause. Several comorbidities and serious associated medical or surgical conditions have been described to be relevant to this syndrome. In general, a preferred initial management with favorable treatment outcomes is virtually to correct underlying disorders. Although disrupted electrolyte homeostasis may induce impaired colonic motility, hypercalcemia secondary to immobilization as a major culprit in this syndrome has rarely been studied. In this report, we profiled radiographic features, therapeutic strategies, and pathogenetic hypothesis of this clinical entity and highlighted the need for clinicians to maintain awareness of this distinct manifestation.


Subject(s)
Colonic Pseudo-Obstruction/diagnosis , Hypercalcemia/diagnosis , Immobilization/adverse effects , Colonic Pseudo-Obstruction/etiology , Humans , Hypercalcemia/etiology , Infarction, Middle Cerebral Artery/complications , Male , Middle Aged , Phenotype
12.
J Psychol ; 146(5): 485-509, 2012.
Article in English | MEDLINE | ID: mdl-22931006

ABSTRACT

Few studies have provided the validity evidence of a measure of objective person-organization fit (P-O fit) as a selection tool. The present study used a concurrent validation design to examine the criterion-related validity and the incremental validity of a P-O fit measure beyond the validity of the Big Five personality test for predicting job performance (task performance and organizational citizenship behavior) and employee commitment (organizational commitment and supervisory commitment) for a group of high-tech professional employees in Taiwan. Results showed that P-O fit predicted the contextual component of overall job performance and was significantly related to two types of employee commitment. Moreover, P-O fit had an incremental validity beyond that of the personality measures for predicting some of our outcome variables.


Subject(s)
Employee Performance Appraisal , Employment/psychology , Organizational Culture , Personality Tests/standards , Personnel Selection/standards , Psychometrics/methods , Adult , Humans , Organizational Objectives , Psychology, Industrial , Psychometrics/standards , Reproducibility of Results
14.
Am J Emerg Med ; 27(2): 251.e1-2, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19371548

ABSTRACT

Immune reconstitution inflammatory syndrome is recognized as a paradoxical worsening of preexisting or smoldering opportunistic infections in patients with human immunodeficiency virus on highly active antiretroviral therapy because of the recuperating of immune system. We report a 42-year-old man on antiretroviral therapy with silent mycobacterium tuberculosis pyomyositis presenting with characteristic clinical and imaging features of immune reconstitution inflammatory syndrome. Because tuberculosis pyomyositis is less recognized and may be easily overlooked in terms of protean manifestations in extrapulmonary tuberculosis spreading, such mycobacterial infection can bring about substantial morbidity and even mortality during the immune recovery phase. The worldwide incidence of human immunodeficiency virus combined with tuberculosis infection is skyrocketing; therefore, emergency physicians must keep a heightened awareness and proficiency of this emerging culprit to obviate unnecessary intervention, preserve organ function, and achieve better outcomes.


Subject(s)
AIDS-Related Opportunistic Infections/immunology , AIDS-Related Opportunistic Infections/microbiology , HIV-1 , Immune Reconstitution Inflammatory Syndrome/immunology , Pyomyositis/immunology , Pyomyositis/microbiology , Tuberculosis/immunology , AIDS-Related Opportunistic Infections/therapy , Adult , Diagnosis, Differential , Humans , Male , Pyomyositis/therapy , Tuberculosis/therapy
15.
Am J Emerg Med ; 27(2): 253.e1-2, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19371552

ABSTRACT

Central retinal artery occlusion is one of the most challenging practices and is not an infrequent presentation at the emergency department. We describe a 46-year-old man presenting with abrupt onset of amaurosis fugax secondary to sentinel central retinal artery occlusion followed by acute idiopathic renal infarction. This patient highlights that the preceding visual events could portend a devastating thromboembolic insult in the clinical setting. Early recognition with prompt treatment may preserve organ function, avoid unnecessary management, and prevent debilitating complication.


Subject(s)
Infarction/diagnosis , Kidney Diseases/diagnosis , Retinal Artery Occlusion/diagnosis , Angiography , Diagnosis, Differential , Humans , Infarction/complications , Kidney Diseases/complications , Male , Middle Aged , Retinal Artery Occlusion/etiology
17.
J Sex Med ; 6(4): 1181-1184, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19207269

ABSTRACT

INTRODUCTION: Priapism is defined as an abnormal prolonged penile erection without sexual interest and failure to subside despite orgasm. The disorder is enigmatic yet devastating because of its elusive etiology, irreversible erectile tissue damage, and resultant erectile dysfunction. A wide variety of provocative factors have been implicated in different types of priapism; however, myelopathy-related ischemic priapism induced by the Valsalva maneuver in the context of spinal extradural arachnoid cyst has never been described. AIM: To report a case with spinal extradural arachnoid cyst heralded by Valsalva maneuver-induced priapism and review the mechanistic basis for acute myelopathy-related priapism. METHODS: The case report profiled a 42-year-old Chinese man presenting with ischemic priapism following in-flight Valsalva maneuver for unblocking the ears during descent. Magnetic resonance imaging unveiled the hidden culprit behind myelopathy-related priapism, as demonstrated by acute spinal cord compression from a giant extradural arachnoid cyst. RESULTS: The symptoms subsided rapidly after treatment with ice packing, analgesics, and corporal irrigation with diluted epinephrine. However, surgical removal of the extradural arachnoid cyst failed to achieve a complete recovery of neurological deficits. After 1 year of follow-ups, he still experienced a mild weakness and hypesthesia of the right leg but no further episodes of priapism or sexual dysfunction. CONCLUSIONS: Myelopathy-related priapism potentiated by the Valsalva maneuver can be easily overlooked without heightened vigilance, leading to poor therapeutic response and prognosis. The indolent nature of spinal extradural arachnoid cyst should be reinforced and better outcomes can only be achieved through expeditious diagnosis and management.


Subject(s)
Asian People , Ischemia/physiopathology , Penis/blood supply , Penis/physiopathology , Priapism/etiology , Priapism/physiopathology , Valsalva Maneuver , Adult , Humans , Male , Spinal Cord Compression/complications , Spinal Cord Diseases/complications
18.
J Natl Med Assoc ; 100(8): 957-9, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18717148

ABSTRACT

Differential diagnosis of a focal splenic lesion in the context of acute leukemia is quite challenging. A 58-year-old woman presented with a 3-day history of fever and abdominal pain. The results of hematological work-up were consistent with acute myeloblastic leukemia (M2, French-American-British classification). Being susceptible to infection in this leukemic patient with severe neutropenia, a diagnosis of splenic abscess was straightforward, plausibly supported by the radiographic findings. Despite empiric broad-spectrum antibiotic treatment, hyperleukocytosis with resultant pulmonary leukostasis supervened. Histological sections from ultrasound-guided percutaneous core-needle biopsy of the spleen confirmed the diagnosis of myeloid sarcoma. However, delayed leukemia-targeted therapy, unfortunately, resulted in catastrophic mortality. It should be addressed that, even with the advent of modern imaging modalities, there can be a diagnostic pitfall when managing solitary splenic lesion in acute leukemic patients without histological examination. Early recognition with prompt chemotherapeutic intervention can be life saving.


Subject(s)
Fever/etiology , Leukemia, Myeloid, Acute/diagnosis , Neutropenia/etiology , Sarcoma, Myeloid/diagnosis , Splenic Neoplasms/diagnosis , Biopsy, Needle , Diagnosis, Differential , Diagnostic Errors , Fatal Outcome , Female , Humans , Leukemia, Myeloid, Acute/complications , Middle Aged , Sarcoma, Myeloid/complications , Spleen/pathology , Splenic Neoplasms/complications , Tomography, X-Ray Computed
20.
Am J Emerg Med ; 26(4): 513.e1-2, 2008 May.
Article in English | MEDLINE | ID: mdl-18410825

ABSTRACT

One-and-a-half syndrome is a clinical disorder featuring extraocular movements characterized by horizontal conjugate gaze palsy with internuclear ophthalmoplegia. It usually results from a unilateral lesion of the midbrain, and the most common cause of this syndrome in young women is multiple sclerosis. We report the case of a 38-year-old woman diagnosed as having acute myeloblastic leukemia presenting with characteristic neurologic and imaging features of one-and-a-half syndrome. Hyperleukocytosis, cancer procoagulants, tissue factor expression, and the increased proteolysis of coagulation factors by leukemic cells may all contribute to the propensity for thrombotic vascular occlusion. The optimal treatment of acute brain infarction in acute leukemia patients with hyperleukocytosis remains unclear. However, this patient illustrates that leukapheresis alone can provide rapid and effective relief of visual symptoms without neurologic sequela. To achieve better outcomes and survival, clinicians must maintain a heightened awareness of this distinctly unusual manifestation.


Subject(s)
Leukemia, Myeloid, Acute/diagnosis , Adult , Antineoplastic Agents/therapeutic use , Brain Stem Infarctions/diagnosis , Brain Stem Infarctions/etiology , Cytarabine/therapeutic use , Diagnosis, Differential , Female , Humans , Leukapheresis , Leukemia, Myeloid, Acute/complications , Leukemia, Myeloid, Acute/therapy , Ocular Motility Disorders/etiology , Syndrome
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