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1.
Nature ; 579(7797): 31-32, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32123361
2.
Acta Chir Orthop Traumatol Cech ; 87(1): 17-23, 2020.
Artículo en Checo | MEDLINE | ID: mdl-32131966

RESUMEN

INTRODUCTION The anterior cruciate ligament (ACL) reconstruction is a tried and tested method in treating knee joint instability which brings valuable results in an acceptable time frame. In the long-term follow-up, however, a higher risk of knee osteoarthritis development is described. One of the possible reasons is considered to be the abnormal kinematics of the operated knee. The purpose of our study was to determine the degree to which the ACL reconstruction helps restore the correct gait cycle compared to the healthy limb. MATERIAL AND METHODS The study included patients after the ACL reconstruction performed in the period from 1 January 2016 to 31 March 2018. With the use of strict criteria, 11 patients were selected for kinematic analysis, who underwent examinations in a gait laboratory and were also evaluated using the Tegner and Lysholm rating systems and the IKDC (International Knee Documentation Committee) knee score, namely preoperatively and at 6 and 12 months postoperatively. The kinematic assessment of gait was carried out using the Vicon MX system with the placement of reflexive markers in line with the Plug-In Gait model. RESULTS The clinical outcomes (namely the score according to Tegner, Lysholm as well as the IKDC) during the first year postoperatively showed a major improvement in knee function and the achievement of the pre-injury activity level. The kinematic analysis revealed lower knee extension at the stance phase and lower overall range of motion of the limb with the injured ACL compared to the healthy limb. The follow-up evaluation at 6 and 12 months postoperatively showed a persisting between-limbs difference in knee extension, whereas the range of motion gradually improved during the year. CONCLUSIONS Although our study confirmed that the ACL reconstruction is an efficient method to treat knee joint instability, it also indicated that even at one year after the ACL reconstruction, the kinematics of the operated knee was not fully restored to the level of the heathy knee. The persisting limb-difference in gait kinematics could contribute to the gradual development of degenerative changes in the operated knee joint. Key words: anterior cruciate ligament deficiency, anterior cruciate ligament reconstruction, knee kinematics during gait, knee osteoarthritis.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior , Reconstrucción del Ligamento Cruzado Anterior , Articulación de la Rodilla , Fenómenos Biomecánicos , Estudios de Seguimiento , Marcha , Humanos , Articulación de la Rodilla/fisiología , Resultado del Tratamiento
3.
Sud Med Ekspert ; 63(1): 56-60, 2020.
Artículo en Ruso | MEDLINE | ID: mdl-32040090

RESUMEN

Two current approaches to the ergometric evaluation of the impact strength that lead to skull fracture are described. Within each of them, the features of particular techniques, typical expert errors, ways and means of preventing them are analyzed. Quantitative data on the contribution of various initial parameters (fracture type, age, bone thickness, skull radius of curvature, body weight, height, etc.) to the result of computational diagnostics are presented.


Asunto(s)
Fracturas Craneales/diagnóstico , Fenómenos Biomecánicos , Medicina Legal , Humanos , Cráneo , Fracturas Craneales/patología
4.
Medicine (Baltimore) ; 99(7): e19046, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32049803

RESUMEN

INTRODUCTION: It is well known that the main segments of spinal fracture is thoracolumbar (T11-L11). Therefore, in addition to the lumbar, the lower thoracic vertebra (T9-T12) often has the clinical needs of implantation of cortical bone trajectory (CBT) screws. However, the anatomic parameters of the lower thoracic vertebrae are quite different from those of the lumbar vertebrae, which means that if CBT screws are to be implanted in the lower thoracic vertebrae, the selection of the screw entry point, the length, diameter, angle and path of the screws in each segment need to be redefined. Methods In this part, 3-dimensional finite element model was established to analyze the stress and fixation efficiency of CBT screws in thoracic vertebrae after 5000 times of fatigue loading of normal model and osteoporosis model. Discussion If the outcomes indicate the trial is feasible and there is evidence to provide some basic anatomical parameters for CBT screw implantation in the lower thoracic spine, so that the ideal insertion point, length, diameter, and angle of CBT screw in different segments of the lower thoracic spine were determined.Trial Registration Chinese Clinical Trial Registry, ChiCTR1900026915.Registered on September 26, 2019.


Asunto(s)
Procedimientos Ortopédicos/instrumentación , Fracturas de la Columna Vertebral/cirugía , Vértebras Torácicas/cirugía , Adulto , Fenómenos Biomecánicos , Tornillos Óseos , Hueso Cortical/anatomía & histología , Hueso Cortical/cirugía , Estudios de Factibilidad , Femenino , Análisis de Elementos Finitos , Humanos , Masculino , Persona de Mediana Edad , Modelos Anatómicos , Vértebras Torácicas/anatomía & histología , Adulto Joven
5.
Nature ; 579(7797): 97-100, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32103182

RESUMEN

The stiff human foot enables an efficient push-off when walking or running, and was critical for the evolution of bipedalism1-6. The uniquely arched morphology of the human midfoot is thought to stiffen it5-9, whereas other primates have flat feet that bend severely in the midfoot7,10,11. However, the relationship between midfoot geometry and stiffness remains debated in foot biomechanics12,13, podiatry14,15 and palaeontology4-6. These debates centre on the medial longitudinal arch5,6 and have not considered whether stiffness is affected by the second, transverse tarsal arch of the human foot16. Here we show that the transverse tarsal arch, acting through the inter-metatarsal tissues, is responsible for more than 40% of the longitudinal stiffness of the foot. The underlying principle resembles a floppy currency note that stiffens considerably when it curls transversally. We derive a dimensionless curvature parameter that governs the stiffness contribution of the transverse tarsal arch, demonstrate its predictive power using mechanical models of the foot and find its skeletal correlate in hominin feet. In the foot, the material properties of the inter-metatarsal tissues and the mobility of the metatarsals may additionally influence the longitudinal stiffness of the foot and thus the curvature-stiffness relationship of the transverse tarsal arch. By analysing fossils, we track the evolution of the curvature parameter among extinct hominins and show that a human-like transverse arch was a key step in the evolution of human bipedalism that predates the genus Homo by at least 1.5 million years. This renewed understanding of the foot may improve the clinical treatment of flatfoot disorders, the design of robotic feet and the study of foot function in locomotion.


Asunto(s)
Evolución Biológica , Fenómenos Biomecánicos , Pie/anatomía & histología , Pie/fisiología , Pruebas de Dureza , Animales , Cadáver , Extinción Biológica , Femenino , Pie/fisiopatología , Hominidae/anatomía & histología , Hominidae/fisiología , Humanos , Persona de Mediana Edad , Pan troglodytes/anatomía & histología , Pan troglodytes/fisiología , Docilidad , Pie Cavo/fisiopatología
6.
J Sports Sci ; 38(6): 597-606, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32005085

RESUMEN

When new protocols are developed, there is a requirement to investigate test-retest reliability of measures for valid use and interpretation of data in research and practice. Therefore, the aim of this investigation was to determine the inter-day reliability of the cable put and seated rotation assessment protocols. On three occasions, nine resistance-trained men performed cable puts and cable rotations at different loads between 6 and 42 kg on a commercially available cable cross over machine. Load stack movement was recorded using a PT5A linear position transducer from which all kinematic and kinetic variables were calculated. Reliability was excellent for peak velocity and displacement based on intraclass correlation coefficient (ICC) and coefficient of variation (CV) across the majority of loads and movements (cable put: ICC = 0.92 to 0.99, CV = 3.1% to 8.6%; cable seated rotation: ICC = 0.76 to 0.99, CV = -1.7% to 16.1%). However, kinetic variables demonstrated inadequate reliability across the majority of days, loads and movements (ICC = 0.70, CV >10%). It was concluded that peak velocity is a reliable kinematic measure to assess muscular capability from cable put and seated rotation protocols; however, kinetic measures are too variable to provide reliable outputs across testing occasions.


Asunto(s)
Prueba de Esfuerzo/métodos , Atletismo/fisiología , Adulto , Fenómenos Biomecánicos , Humanos , Cinética , Masculino , Fuerza Muscular/fisiología , Reproducibilidad de los Resultados , Entrenamiento de Resistencia , Rotación , Adulto Joven
7.
J Sports Sci ; 38(6): 652-657, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32009512

RESUMEN

The purpose of this study was to investigate subject- and joint-specific strategies used by male basketball players as they increase their countermovement jump (CMJ) height from sub-maximal to maximal efforts. Lower extremity joint kinematics and kinetics were recorded as 11 male, NCAA Division I basketball players performed 8-10 CMJ across effort levels of approximately 25%, 50%, 75% and 100%. Simple correlation models were used to investigate the associations between effort levels (i.e., CMJ height) and joint mechanics (i.e., negative (eccentric) and positive (concentric) mechanical work performed at the hip, knee, and ankle joints) for each individual player and the entire group. Group-analyses showed that increases in all joint mechanical variables were associated with increases in CMJ height. In contrast, single-subject analyses revealed that players used individualised strategies, and selectively scaled the magnitude of mechanical work at none (n = 2), one (n = 2), two (n = 5), or all three (n = 2) joints as they increased CMJ efforts. In addition, individual players also appeared to selectively scale different combinations of eccentric or concentric joint work as they increased CMJ height. These results highlight that male basketball players use joint-specific strategies to increase CMJ height when progressively increasing CMJ effort.


Asunto(s)
Articulación del Tobillo/fisiología , Baloncesto/fisiología , Articulación de la Cadera/fisiología , Articulación de la Rodilla/fisiología , Ejercicio Pliométrico , Fenómenos Biomecánicos , Humanos , Cinética , Masculino , Análisis y Desempeño de Tareas , Adulto Joven
8.
Medicine (Baltimore) ; 99(5): e18941, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32000413

RESUMEN

The abnormal inter-segmental coordination of the spine during lifting could be used to monitor disease progression and rehabilitation efficacy in patients with ankylosing spondylitis (AS). This study aimed to compare the inter-segmental coordination patterns and variability of the spine during lifting between patients with AS (n = 9) and control (n = 15) groups.Continuous relative (CRP) and deviation (DP) phases between each segment of the spine (two lumbar and three thorax segments) and lumbosacral joint were calculated. The CRP and DP curves among participants were decomposed into few functional principal components (FPC) via functional principal component analysis (FPCA). The FPC score of CRP or DP of the two groups were compared, and its relationship with the indexes of spinal mobility was investigated.Compared with the control group, the AS patients showed more anti-phase coordination patterns in each relative upper spine segment and lumbosacral joint. In addition, either less or more variation was found in the coordination of each relative lower spine segment and lumbosacral joint during different time periods of lifting for these patients. Some cases were considerably related to spinal mobility.the inter-segmental coordination of the spine was altered during lifting in AS patients to enable movement, albeit inefficient and might cause spinal mobility impairment.


Asunto(s)
Elevación , Movimiento/fisiología , Columna Vertebral/fisiopatología , Espondilitis Anquilosante/fisiopatología , Fenómenos Biomecánicos , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pelvis/fisiopatología , Rango del Movimiento Articular
9.
J Sports Sci ; 38(6): 710-716, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32079484

RESUMEN

The purpose of this study was to investigate the validity of a smartphone app to measure biomechanical barbell parameters during the snatch. Ten collegiate NCAA division I athletes performed two repetitions each at 40, 50, 60, 70, and 80% of their 1-repetition maximum snatch. Barbell motions were simultaneously recorded with a motion capture system and the smartphone app. The motion capture system recorded the 3-D position of a reflective marker attached to the end of the barbell while the smartphone app was used to record sagittal plane video and track the shape of the weight plate from which the barbell center was derived. Peak forward (PFD) and backward (PBD) displacements and peak vertical displacement (PVD) and velocity (PVV) were calculated from both sets of data. Significant, strong to very strong Pearson's product-moment correlation coefficients between both systems were noted for all parameters (r = 0.729-0.902, all p < 0.001). Small significant biases between systems were observed for PVD (ES = 0.284, p < 0.001) and PFD (ES=0.340, p < 0.01), while trivial to small, non-significant biases were observed for PBD (ES = 0.143) and PVV (ES = -0.100). Collectively, the results suggest that the app can provide biomechanical data of barbell motions similar to a 3-D motion capture system.


Asunto(s)
Rendimiento Atlético/fisiología , Teléfono Inteligente , Validación de Programas de Computación , Levantamiento de Peso/fisiología , Fenómenos Biomecánicos , Humanos , Reproducibilidad de los Resultados , Estudios de Tiempo y Movimiento , Adulto Joven
10.
Zhonghua Yan Ke Za Zhi ; 56(2): 103-109, 2020 Feb 11.
Artículo en Chino | MEDLINE | ID: mdl-32074820

RESUMEN

Objective: To investigate the application value of Pentacam combined with Corvis ST in evaluation of the changes of corneal biomechanics after femtosecond laser small incision lenticule extraction (SMILE) in Chinese myopia with an irregular cornea. Methods: The clinical records for 104 eyes of 57 patients who received SMILE in the Refractive Center of Beijing Tongren Hospital during January 2018 and May 2018 were collected. According to the keratoconus severity index (KSI), they were divided into two groups: regular corneal group (KSI<15%) and irregular corneal group (KSI: 15% to 25%). In both groups, the anterior corneal surface radius curvature was>7.25 mm (K<46.50 diopters), the posterior corneal surface radius curvature was>5.90 mm, the thinnest pachymetry was>490 µm, and best corrected visual acuity was ≥1.0. The vision, refraction, and corneal biomechanics before and after SMILE were assessed. The Topographic and Biomechanics Index (TBI) was analyzed by Pentacam combined with Corvis ST. Results: Before SMILE, the Corvis Biomechanical Index (CBI), TBI, and Belin/Ambrósio Deviation Normalized Index (BADD) of the irregular corneal group were significantly higher (t=-2.17, -6.78, -4.37, P<0.05) than the regular corneal group, while the stiffness parameter (SPA1) was significantly lower (t=2.58, P=0.011) compared to the regular corneal group (P<0.05). In the irregular group, the TBI was (0.28±0.2); the maximum value was 0.03, and the minimum value was 0.43. The CBI was (0.09±0.21); the maximum value was 0.00, and the minimum value was 0.54. The BADD was (1.33±0.47); the maximum value was 0.42, and the minimum value was 2.26. In the regular group, the TBI was (0.05±0.08); the maximum value was 0.00, and the minimum value was 0.20. The CBI was (0.01±0.03); the maximum value was 0.00, and the minimum value was 0.17. The BADD was (0.92±0.46); the maximum value was 0.00, and the minimum value was 1.64. There was no significant difference between two groups in age (t=0.20, P=0.508), central corneal thickness (t=1.64, P=0.104), biomechanical corrected IOP (t=0.73, P=0.468), max inverse radius (t=-0.24, P=0.815), spherical equivalent (t=-0.97, P=0.335), and best corrected visual acuity (t=0.21, P=0.833). After SMILE, the deformation amplitude in the irregular group was significantly higher at 1 month and 3 months (t=-3.13, -3.09, P<0.05). The irregular group had a significantly higher deformation amplitude ratio at 1 week, 1 month, and 1 year (t=-2.72, -3.39, -2.51, P<0.05). The SPA1 in the irregular group was significantly lower than the regular group at 1 week, 1 month, and 3 months (t=2.11, 2.73, 3.70, P=0.335, 0.010,<0.001). The changes of deformation amplitude (t=0.50, -1.10, -0.73, 2.12, P>0.05), max inverse radius (t=-1.52, -1.41, 0.01, -0.79, P>0.05), and SPA1(t=0.89, 0.90, 1.12, 0.90, P>0.05) after SMILE were similar between the irregular and regular groups, except that at 1 month after SIMILE, the deformation amplitude ratio changed more significantly in the irregular group (t=-3.01, P=0.003). Conclusions: The changes of corneal biomechanics in the groups of regular cornea and irregular cornea were stable with no significant difference during 1 year of post-SMILE. The diagnosis based on the corneal topography and corneal biomechanics is of certain significance for the screening of early keratoconus before keratorefractive surgery. (Chin J Ophthalmol, 2020, 56:103-109).


Asunto(s)
Córnea , Queratocono , Miopía , Fenómenos Biomecánicos , Córnea/fisiología , Córnea/cirugía , Sustancia Propia , Topografía de la Córnea , Humanos , Agudeza Visual
11.
Zhonghua Yan Ke Za Zhi ; 56(2): 110-117, 2020 Feb 11.
Artículo en Chino | MEDLINE | ID: mdl-32074821

RESUMEN

Objective: To investigate the influence factors and differences of abnormal posterior corneal elevation by Pentacam system and Corvis ST. Methods: This retrospective case series study included 227 eyes of 144 patients (90 males, 139 eyes; 54 females, 88 eyes) from December 2017 to October 2018 who were going to receive corneal refractive surgery at the Corneal Refraction Department of Qingdao Eye Hospital. The general data of the patients including gender, age, refractive parameters, optimal correction of spherical and cylindrical diopters were collected. All patients underwent Pentacam system and Corvis ST measurement. According to the back difference (BD) of Pentacam parameters, BD<12 µm was set as the control group (59 patients, 118 eyes) and BD≥12 µm as the high BD group (85 patients, 109 eyes). In the high BD group, BD≤16 µm was set as the suspicious group (44 patients, 53 eyes), while BD>16 µm was set as the abnormal group (41 patients, 56 eyes). Seven parameters of Pentacam and 15 parameters of Corvis ST were selected. The Pentacam parameters included BD, anterior surface keratometry (ASK), posterior surface keratometry (PSK), anterior surface astigmatism (AAstig), posterior surface astigmatism (PAstig), central corneal thickness (CCT), and corneal diameter (W-W). The parameters of Corvis ST included the first applanation time (AT(1)), the first applanation length (AL(1)), the first applanation velocity (AV(1)), the second applanation time (AT(2)), the second applanation length (AL(2)), the second applanation velocity (AV(2)), highest concavity time (HCT), highest concavity peak distance (HC-PD), highest concavity deformation amplitude (HC-DA), highest concavity radius (HC-R), the ratio of deformation amplitude (DA ratio), Integr. Radius, corneal thickness thinnest/pachymetric progression (ARTh), SPA1 (resultant pressure divided by deflection amplitude at the first applanation), and the Corvis Biomechanical Index (CBI). The comparison between the groups was analyzed with Independent sample t test, Kruskal-Wallis H test, and Bonferroni test. Spearman rank correlation analysis was used to explore the correlation factors of BD, and the main factors affecting BD were found through multiple linear regression. Results: There were no statistically significant differences between the control group and the high BD group in age, spherical diopters, and cylindrical diopters (t=-3.311, -1.808, -2.359; P=0.071, 0.072, 0.121, respectively). In Pentacam parameters, ASK, PSK, PAstig, and W-W showed significant differences among groups (Z=18.492, 31.547, 10.773, 70.167; P<0.05). AAstig and CCT showed no statistical difference between groups (P>0.05). Compared with the control group [42.80 (41.98, 44.00)], ASK increased in the abnormal group [43.40 (42.20, 44.40)] significantly (t=-4.292; P<0.05). PSK of the suspicious group [-6.50 (-6.60, -6.35)] and the abnormal group [-6.50 (-6.70, -6.33)] increased significantly compared with the control group [-6.30 (-6.50, -6.20)] (t=4.492, 4.618; P<0.05). Compared with the control group [0.40 (0.30, 0.50)], PAstig of the suspicious group [0.40 (0.30, 0.40)] and the abnormal group [0.40 (0.30, 0.40)] increased significantly (t=2.796, 2.515; P=0.016, 0.036). Compared with the control group [11.50 (11.40, 11.80)], W-W of the suspicious group [11.40 (11.00, 11.60)] and the abnormal group [11.10 (10.90, 11.30)] decreased, and W-W of the abnormal group also decreased significantly compared with the suspicious group (t=3.235, 8.353, 4.282; P<0.05). The correlation analysis between BD and Pentacam parameters of patients in each group showed that BD was negatively correlated with W-W (r=-0.614, -0.304, -0.396, -0.661, P<0.05) in the control group, the suspicious group, the abnormal group, and all patients, while BD had a low correlation with other parameters or no significant correlation. The correlation analysis of BD and Corvis ST parameters in patients showed that only in the suspicious group, BD was positively correlated with AV(1), HCT, and HC-DA (r=0.332, 0.361, 0.382, P<0.05), while no significant correlation was found between BD and other Corvis ST parameters in each group. In order to further explore the main factors affecting BD, Pentacam parameters and Corvis ST parameters were selected as independent variables with BD as the dependent variable to establish a multivariate linear regression analysis model. There was no collinearity between variables W-W, ASK, PSK, HC-PD, SPA1, and CCT (tolerance<0.100). The equation test result was F=37.221, P<0.001, adjusted r(2)=0.504, and the fitting was good. Conclusions: Among the Pentacam parameters, W-W, ASK, and PSK are the main factors affecting the change of BD. HC-PD and SPA1 in the Corvis ST parameters may also have some influence on BD. The Pentacam system combined with Corvis ST is a very useful differential diagnosis system for patients with abnormal BD. (Chin J Ophthalmol, 2020, 56:110-117).


Asunto(s)
Córnea , Presión Intraocular , Tonometría Ocular , Fenómenos Biomecánicos , Córnea/anomalías , Femenino , Humanos , Masculino , Estudios Retrospectivos
12.
Unfallchirurg ; 123(2): 89-96, 2020 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-31970427

RESUMEN

The treatment of flexor tendon injuries is still challenging, especially in the region of the narrow annular ligaments and tendon sheaths of the 3­segment fingers and the thumb (zone 2). In the course of time, the primary suture of the flexor tendons has prevailed over traditional recommendations for a secondary tendon replacement after healing of the wound. Improvements regarding suture techniques and materials and, above all the follow-up treatment, have been crucial for better results and remarkable changes in flexor tendon surgery. The suture techniques are determined by the location of the injury but the experience and preferences of the surgeon are also important. Although no technique was found to be optimal, published research and clinical experiences provide important indications for the presumption of successful treatment. To achieve this an early functionally active protocol should be implemented. The tendon suture should enable this by having a high primary strength and therefore at least a 4-strand core suture technique with a ring suture should be given preference. Further important prerequisites for success are the undisturbed gliding of the repaired tendon in its "bed" paying special attention to the annular ligaments and preservation of the blood supply to the tendons.


Asunto(s)
Traumatismos de los Tendones , Fenómenos Biomecánicos , Dedos , Humanos , Técnicas de Sutura , Suturas , Traumatismos de los Tendones/terapia , Tendones
13.
J Oral Sci ; 62(1): 18-22, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31996517

RESUMEN

This study used 320-row area detector computed tomography (320-ADCT) to determine whether kinematic swallowing events and bolus movement through the oropharynx are affected by bolus consistency and angle of recline. Fourteen healthy adults (4 men, 10 women; age, 22-90 years) underwent 320-ADCT assessment during three 10-mL barium swallow tests, with honey-thick liquid at 60° recline (60°thick), thin liquid at 60° recline (60°thin), and thin liquid at 45° recline (45°thin). The times of swallowing events were measured and compared among the different tests. Bolus propulsion, onset time of true vocal cord (TVC) closure, and upper esophageal sphincter opening were significantly earlier for 60°thin than for 60°thick. Onset time did not significantly differ between 60°thin and 45°thin; however, greater variability was noted for onset of TVC closure with 45°thin, as the TVC started to close before onset of swallowing in 30% of participants. Modulation of TVC closure depends on bolus transport in different reclining positions. The 45° reclining position elicited pre-swallow TVC closure in some participants, which suggests that excessive recline can increase perceived risk of airway invasion during swallowing.


Asunto(s)
Deglución , Tomografía Computarizada por Rayos X , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Movimiento
14.
Bone Joint J ; 102-B(1): 117-124, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31888372

RESUMEN

AIMS: It is unknown whether kinematic alignment (KA) objectively improves knee balance in total knee arthroplasty (TKA), despite this being the biomechanical rationale for its use. This study aimed to determine whether restoring the constitutional alignment using a restrictive KA protocol resulted in better quantitative knee balance than mechanical alignment (MA). METHODS: We conducted a randomized superiority trial comparing patients undergoing TKA assigned to KA within a restrictive safe zone or MA. Optimal knee balance was defined as an intercompartmental pressure difference (ICPD) of 15 psi or less using a pressure sensor. The primary endpoint was the mean intraoperative ICPD at 10° of flexion prior to knee balancing. Secondary outcomes included balance at 45° and 90°, requirements for balancing procedures, and presence of tibiofemoral lift-off. RESULTS: A total of 63 patients (70 knees) were randomized to KA and 62 patients (68 knees) to MA. Mean ICPD at 10° flexion in the KA group was 11.7 psi (SD 13.1) compared with 32.0 psi in the MA group (SD 28.9), with a mean difference in ICPD between KA and MA of 20.3 psi (p < 0.001). Mean ICPD in the KA group was significantly lower than in the MA group at 45° and 90°, respectively (25.2 psi MA vs 14.8 psi KA, p = 0.004; 19.1 psi MA vs 11.7 psi KA, p < 0.002, respectively). Overall, participants in the KA group were more likely to achieve optimal knee balance (80% vs 35%; p < 0.001). Bone recuts to achieve knee balance were more likely to be required in the MA group (49% vs 9%; p < 0.001). More participants in the MA group had tibiofemoral lift-off (43% vs 13%; p < 0.001). CONCLUSION: This study provides persuasive evidence that restoring the constitutional alignment with KA in TKA results in a statistically significant improvement in quantitative knee balance, and further supports this technique as a viable alternative to MA. Cite this article: Bone Joint J. 2020;102-B(1):117-124.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/métodos , Prótesis de la Rodilla , Osteoartritis de la Rodilla/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Fenómenos Biomecánicos , Femenino , Humanos , Curva de Aprendizaje , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Osteoartritis de la Rodilla/fisiopatología , Planificación de Atención al Paciente , Cuidados Preoperatorios , Implantación de Prótesis/métodos , Rango del Movimiento Articular/fisiología , Resultado del Tratamiento
15.
Medicine (Baltimore) ; 99(2): e18609, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31914039

RESUMEN

BACKGROUND: Cerebral palsy (CP) is a common disability in children featured with pathological gait and limb function limitation due to muscle weakness. Improving limb function and quality of life is currently considered to be highlighted. Physiotherapy is a chief component of rehabilitation for children with CP, correcting gait and improve walking capacity through muscle strength training. Standard rehabilitation programs for CP have not been determined. Core stability training (CST), which coordinates limb balance via trunk control, is widely used in sports competition. And it is gradually introduced into the rehabilitation of children with cerebral palsy with a positive impact on the patients' gait performance. By screening published literatures, this study aims to conduct a meta-analysis to systematically evaluate the effectiveness and safety of CST in gait of children with CP. METHODS: Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) on CST in the treatment of children with CP were searched from 6 databases. Moreover, the reference lists of conference papers and included literatures will be manually searched to avoid omissions. Literature screening and data extraction were performed independently by 2 researchers. RCTs carry out the risk of bias analysis evaluation from seven aspects through the Cochrane Collaboration's risk of bias tool. Fixed or random effect model will be performed to analyze the outcomes. When higher heterogeneity occurs (I > 50%), the sensitivity or subgroup analysis will also be conducted to find potential factors. And the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach is used for assessing the quality of evidence. RESULTS: The study will evaluate the effect of CST on gait of children with CP from multiple outcomes, including walking speed, endurance, stride length, and safety. CONCLUSION: Based on evidence-based medicine, the conclusion of this study can demonstrate the effectiveness and safety of CST in gait correction for children with CP. PROSPERO REGISTRATION NUMBER: PROSPERO CRD 42019134094.


Asunto(s)
Parálisis Cerebral/rehabilitación , Terapia por Ejercicio/métodos , Fenómenos Biomecánicos , Niño , Ensayos Clínicos como Asunto , Femenino , Humanos , Masculino , Metiltiouracilo , Fuerza Muscular , Proyectos de Investigación
16.
J Zoo Wildl Med ; 50(4): 910-916, 2020 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-31926523

RESUMEN

Assessment of pododermatitis, osteoarthritis, and other causes of lameness in penguins can be challenging. Subjective gait analysis using visual observation and response to analgesic therapy can be affected by observer variation and caregiver placebo bias. A pressure-sensitive walkway (PSW), however, allows for objective gait analysis and assessment of analgesic therapeutic response. In this study, a 3-m-long PSW was used to analyze gait in 21 adult Humboldt penguins (Spheniscus humboldti). Medical record reviews and comprehensive examinations were performed on all penguins; five penguins were considered abnormal, with either right-sided (n = 3) or bilateral historical lameness-causing disease (n = 2) and were analyzed separately from the normal data set. All penguins walked across the PSW four times and gait parameters (step and stride distances and velocities, maximum force, impulse, and peak pressure) were calculated for each foot in each penguin. Statistical comparisons were made between right and left feet, sexes, and normal and abnormal penguins for each gait parameter. Among normal penguins, there were no significant differences between feet or sex. Left step width was shorter in abnormal penguins than that of normal penguins. Study results established baseline values for Humboldt penguins. This will allow objective monitoring of progression and response to therapy in penguin lameness cases, both current and future. The data also provide a foundation to compare gait parameters with other penguin populations and species.


Asunto(s)
Análisis de la Marcha/veterinaria , Marcha , Spheniscidae/fisiología , Animales , Animales de Zoológico , Fenómenos Biomecánicos , Femenino , Análisis de la Marcha/instrumentación , Análisis de la Marcha/métodos , Masculino
18.
Niger J Clin Pract ; 23(1): 79-83, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31929211

RESUMEN

Objectives: The aim of this study was to evaluate the quantity of apically extruded debris after canal shaping with three single-file systems. Materials and Methods: Sixty mesiobuccal canals of mandibular molars were divided into three experimental groups according to the used file systems-WaveOne Gold, RECIPROC Blue, and HyFlex EDM One file. Debris extruded during canal shaping were collected in preweighed vials. Each canal was irrigated with 5 mL of distilled water via a 30 G side-vented needle. The amount of the debris extruded from each canal was calculated by subtracting the preinstrumentation from postinstrumentation measurement. The preparation times were recorded. Data were analyzed using analysis of variance (ANOVA) and posthoc Tukey tests with α = 0.05. Results: WaveOne Gold extruded the least amount of debris. Results between WaveOne Gold and HyFlex EDM were significantly different. No significant differences in canal shaping time were detected among the three groups (P > 0.05). Conclusion: WaveOne Gold showed the best results regarding apical debris extrusion. Difference between WaveOne Gold and HyFlex EDM suggests that file design and motion kinematics affect the quantity of debris extrusion.


Asunto(s)
Cavidad Pulpar/cirugía , Preparación del Conducto Radicular/instrumentación , Ápice del Diente/cirugía , Fenómenos Biomecánicos , Cavidad Pulpar/anatomía & histología , Diseño de Equipo , Humanos , Diente Molar/anatomía & histología , Diente Molar/cirugía , Preparación del Conducto Radicular/métodos
19.
J Sports Sci ; 38(5): 542-551, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31924128

RESUMEN

Males and females demonstrate unique running mechanics that may contribute to sex-related differences in common running related injuries. Understanding differences in muscle forces during running may inform intervention approaches, such as gait retraining addressing muscle force distribution. The purpose of this study was to compare muscle force characteristics and inter-trial variability between males and females during running. Twenty female and 14 male collegiate cross-country runners were examined. Three-dimensional kinetic and kinematic data were collected during overground running and used to estimate muscle forces via musculoskeletal modelling. Principle components analysis was used to capture the primary sources of variance from the muscle force waveforms. The magnitude of the forces for the hamstrings, gastrocnemius, and soleus muscles were higher across the majority of stance in male runners regardless of footstrike pattern. Males also demonstrated greater inter-trial variability in the timing of the peak gluteus maximus force and the magnitude of local peaks in the gastrocnemius force waveform. Male and female collegiate cross-country runners appear to employ unique lower extremity muscle force characteristics during overground running.


Asunto(s)
Músculo Esquelético/fisiología , Carrera/fisiología , Adolescente , Fenómenos Biomecánicos/fisiología , Femenino , Marcha/fisiología , Músculos Isquiotibiales/fisiología , Humanos , Extremidad Inferior/fisiología , Masculino , Análisis Multivariante , Músculo Cuádriceps/fisiología , Factores Sexuales , Adulto Joven
20.
Phys Chem Chem Phys ; 22(3): 1092-1096, 2020 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-31894209

RESUMEN

Mechanical force plays a critical role in the relationship between protein structure and function. Force manipulation by Atomic Force Microscope can be significant and trigger chemical and biological activities of proteins. Previously we have reported that Apo-CaM undergoes through a spontaneous tertiary structural rupture under a piconewton compressive force. Here we have observed that the ruptured Apo-CaM molecules can be available to bind with C28W peptide, a typical protein signalling activity that only a Ca2+-activated CaM has. This behaviour is both unexpected and profound, as CaM in its Ca2+-non-activated form has a closed structure which does not presumably allow the molecule to bind to target peptides. In this experiment, we demonstrate that both chemical activation and force activation can play a vital role in biology, such as the cell-signalling protein dynamics and function.


Asunto(s)
Calmodulina/química , Proteínas/química , Transducción de Señal , Fenómenos Biomecánicos , Unión Proteica , Estructura Terciaria de Proteína
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