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1.
J Appl Biomech ; 39(4): 230-236, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37328156

RESUMO

Standing pelvic tilt (PT) is related to biomechanics linked with increased risk of injury such as dynamic knee valgus. However, there is limited evidence on how standing PT relates to dynamic PT and whether the palpation meter (PALM), a tool to measure standing PT, is valid against 3-dimensional (3D) motion analysis. The purposes of this study were to (1) determine the criterion validity of the PALM for measuring standing PT and (2) identify the relationship between standing PT and dynamic PT during running. Participants (n = 25; 10 males and 15 females) had their standing PT measured by the PALM and 3D motion analysis. Dynamic PT variables were defined at initial contact and toe off. No relationship between the 2 tools was found. Significant large positive relationships between standing PT and PT at initial contact (r = .751, N = 25, P < .001) and PT at toe off (r = .761, N = 25, P < .001) were found. Since no relationship was found between standing PT measured by the PALM and 3D motion analysis, the PALM is not a valid alternative to 3D motion analysis. Clinicians may be able to measure standing PT and gain valuable information on dynamic PT, allowing clinicians to quickly assess whether further biomechanical testing is needed.


Assuntos
Captura de Movimento , Corrida , Masculino , Feminino , Humanos , Postura , Posição Ortostática , Movimento (Física)
2.
J Sport Rehabil ; 32(1): 85-90, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35940581

RESUMO

CONTEXT: Women's volleyball requires frequent and repetitive jumping that when performed with altered biomechanics, including kinematic or kinetic asymmetry, may place the athlete at high risk for injury. This study identified and analyzed lower-extremity biomechanical asymmetries in college women's volleyball players during standard and sport-specific double-leg landing tasks. DESIGN: Cross-sectional laboratory study. METHODS: Eighteen female college volleyball players were analyzed using standard 3D motion capture techniques during a drop vertical jump and an unanticipated lateral reactive jump task. Repeated-measures multivariate analysis of variance identified asymmetries in kinematic and kinetic variables of each task. RESULTS: Average symmetry indices ranged from 9.3% to 31.3% during the drop vertical jump and 11.9% to 25.6% during the reactive jump task. During the drop vertical jump, the dominant limb exhibited lower knee abduction moments (P = .03), ankle dorsiflexion moments (P = .02), ankle eversion moments (P = .003) and vertical ground reaction forces (P = .03), and greater ankle inversion moments (P = .001). Both kinematic (λ = 0.27, P = .03) and kinetic (λ = 0.12, P = .008) asymmetries were identified during the reactive jump task. The dominant limb exhibited greater peak knee flexion (P = .003) and ankle dorsiflexion (P = .02) angles, and greater ankle dorsiflexion (P = .005) and inversion (P = .03) moments than the nondominant limb. CONCLUSIONS: These asymmetries observed during double-leg landing tasks may predispose volleyball athletes to unilaterally higher ground reaction or muscle forces and ultimately a greater risk of injury during landing.


Assuntos
Lesões do Ligamento Cruzado Anterior , Voleibol , Humanos , Feminino , Perna (Membro)/fisiologia , Voleibol/lesões , Estudos Transversais , Extremidade Inferior , Articulação do Joelho/fisiologia , Fenômenos Biomecânicos
3.
J Strength Cond Res ; 36(2): 503-507, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32028463

RESUMO

ABSTRACT: Devine, NF, Hegedus, EJ, Nguyen, A-D, Ford, KR, and Taylor, JB. External match load in women's collegiate lacrosse. J Strength Cond Res 36(2): 503-507, 2022-Quantifying external loads during athletic activities, particularly game-level competition, can provide objective data for the management of athlete performance, late-stage rehabilitation, and return-to-play decisions after lower extremity injury; yet, no studies have quantified these data in collegiate women's lacrosse athletes. The purpose of this study was to report external load values for collegiate women's lacrosse players and identify positional differences in activity demands during game competition. Load data were collected on 18 collegiate women's lacrosse players using a wearable global positioning system unit during a 19-game season. Descriptive statistics of distance, speed, and frequency (sprints, high-intensity sprints, high-intensity accelerations, high-intensity decelerations) measures were computed. Linear mixed models were used to identify differences between positions and phases of the season (α = 0.05). On average, players travelled 4,733 ± 2,294 m per game (range, 1,259-7,811 m), of which 656 ± 446 m (range 60-1,633 m) occurred at high-intensity speeds and reached a maximum speed of 24.1 ± 2.6 km·h-1 (range, 19.2-27.7 km·h-1). In each game, subjects averaged 124 ± 68 sprints, 6.1 ± 4.1 high-intensity sprints, 51 ± 34 high-intensity accelerations, and 38 ± 25 high-intensity decelerations. Positional differences were identified for total (p = 0.04) and relative (p = 0.01) distance travelled at high-intensity speeds, and frequency of sprints (p = 0.01) and high-intensity decelerations (p = 0.03). During game competition, collegiate women's lacrosse demands significant external load, much of which occurs at high intensities. These data provide sport- and position-specific values for reference during late-stage rehabilitation and return-to-play testing, allowing clinicians to quantitatively progress load tolerance throughout rehabilitation and guide safe return to play.


Assuntos
Desempenho Atlético , Esportes com Raquete , Aceleração , Atletas , Feminino , Humanos , Universidades
4.
Clin J Sport Med ; 31(1): 49-56, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30689611

RESUMO

OBJECTIVE: To determine the association between selected biomechanical variables and risk of patellofemoral pain (PFP) in males and females. DESIGN: Prospective cohort. SETTING: US Service Academies. PARTICIPANTS: Four thousand five hundred forty-three cadets (1727 females and 2816 males). ASSESSMENT OF RISK FACTORS: Three-dimensional biomechanics during a jump-landing task, lower-extremity strength, Q-angle, and navicular drop. MAIN OUTCOME MEASURES: Cadets were monitored for diagnosis of PFP during their enrollment in a service academy. Three-dimensional hip and knee kinematic data were determined at initial contact (IC) and at 50% of the stance phase of the jump-landing task. Logistic regression analyses were performed for each risk factor variable in males and females (P < 0.05). RESULTS: Less than 10 degrees of hip abduction at IC [odds ratio (OR) = 1.86, P = 0.03] and greater than 10 degrees of knee internal rotation at 50% of the stance phase (OR = 1.71, P = 0.02) increased the risk of PFP in females. Greater than 20 degrees of knee flexion at IC (OR = 0.47, P < 0.01) and between 0 and 5 degrees of hip external rotation at 50% of the stance phase (OR = 0.52, P = 0.04) decreased the risk of PFP in males. No other variables were associated with risk of developing PFP (P > 0.05). CONCLUSIONS: The results suggest males and females have differing kinematic risk factor profiles for the development of PFP. CLINICAL RELEVANCE: To most effectively reduce the risk of developing PFP, the risk factor variables specific to males (decreased knee flexion and increased hip external rotation) and females (decreased hip abduction and increased knee internal rotation) should be addressed in injury prevention programs.


Assuntos
Síndrome da Dor Patelofemoral/epidemiologia , Fatores Sexuais , Adolescente , Fenômenos Biomecânicos , Feminino , Humanos , Joelho , Extremidade Inferior , Masculino , Militares , Estudos Prospectivos , Amplitude de Movimento Articular , Fatores de Risco , Rotação , Adulto Jovem
5.
J Sport Rehabil ; 30(6): 942-951, 2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33662925

RESUMO

CONTEXT: A bias toward femoral internal rotation is a potential precursor to functional valgus collapse. The gluteal muscles may play a critical role in mitigating these effects. OBJECTIVE: Determine the extent to which gluteal strength and activation mediate associations between femoral alignment measures and functional valgus collapse. DESIGN: Cross-sectional. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: Forty-five females (age = 20.1 [1.7] y; height = 165.2 [7.6] cm; weight = 68.6 [13.1] kg) and 45 males (age = 20.8 [2.0] y; height = 177.5 [8.7] cm; weight = 82.7 [16.5] kg), healthy for 6 months prior. INTERVENTION(S): Femoral alignment was measured prone. Hip-extension and abduction strength were obtained using a handheld dynamometer. Three-dimensional biomechanics and surface electromyography were obtained during single-leg forward landings. MAIN OUTCOME MEASURES: Forward stepwise multiple linear regressions determined the influence of femoral alignment on functional valgus collapse and the mediating effects of gluteus maximus and medius strength and activation. RESULTS: In females, less hip abduction strength predicted greater peak hip adduction angle (R2 change = .10; P = .02), and greater hip-extensor activation predicted greater peak knee internal rotation angle (R2 change = .14; P = .01). In males, lesser hip abduction strength predicted smaller peak knee abduction moment (R2 change = .11; P = .03), and the combination of lesser hip abduction peak torque and lesser gluteus medius activation predicted greater hip internal rotation angle (R2 change = .15; P = .04). No meaningful mediation effects were observed (υadj < .01). CONCLUSIONS: In females, after accounting for femoral alignment, less gluteal strength and higher muscle activation were marginally associated with valgus movement. In males, less gluteal strength was associated with a more varus posture. Gluteal strength did not mediate femoral alignment. Future research should determine the capability of females to use their strength efficiently.


Assuntos
Articulação do Quadril , Perna (Membro) , Força Muscular , Músculo Esquelético/fisiologia , Fenômenos Biomecânicos , Nádegas , Estudos Transversais , Feminino , Fêmur , Humanos , Articulação do Joelho , Masculino , Adulto Jovem
6.
Clin J Sport Med ; 30(3): 279-281, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32341293

RESUMO

OBJECTIVE: To identify relationships between self-reported limb preferences and performance measures for determining limb dominance in adolescent female basketball players. DESIGN: Cross-sectional cohort study. PARTICIPANTS: Forty adolescent female basketball players. INDEPENDENT VARIABLES AND MAIN OUTCOME MEASURES: Participants provided self-reported preferred kicking and jumping limbs, then completed 3 trials of a single-limb countermovement hop (HOPVER) and unilateral triple hop for distance (HOPHOR) on each limb. Each test was used to independently define limb dominance by the limb that produced the largest maximum vertical height and horizontal distance, respectively. RESULTS: Chi-square tests for independence identified a significant relationship between self-reported preferred kicking and jumping legs (χ = 7.41, P = 0.006). However, no significant relationships were found when comparing self-reported preference to measures of performance during the HOPHOR (χ = 0.33, P = 0.57) or HOPVER (χ = 0.06, P = 0.80). In addition, the 2 performance measures did not consistently produce the same definition of limb dominance among individuals (χ = 1.52, P = 0.22). CONCLUSIONS: Self-selection of the dominant limb is unrelated to performance. Furthermore, limb dominance, as defined by vertical jump height, is unrelated to limb dominance defined by horizontal jump distance. The results of this study call into question the validity of consistently defining limb dominance by self-reported measures in adolescent female basketball players.


Assuntos
Basquetebol/fisiologia , Lateralidade Funcional/fisiologia , Extremidade Inferior/fisiologia , Adolescente , Fenômenos Biomecânicos , Estudos Transversais , Teste de Esforço , Feminino , Humanos , Autorrelato
7.
Knee Surg Sports Traumatol Arthrosc ; 28(4): 1236-1245, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30259145

RESUMO

PURPOSE: To investigate the differences in demographic, anthropometric, biomechanical, and/or performance variables between those that do (responders) and do not (non-responders) exhibit reductions in knee abduction moments after an anterior cruciate ligament injury prevention program (ACL-IPP). METHODS: Forty-three adolescent female athletes completed biomechanical (3D motion analysis of a drop vertical jump) and performance testing before and after randomization into a 6-week ACL-IPP. Participants were classified into responders and non-responders based on their level of reduction of knee abduction moment from pre- to post-test. RESULTS: Compared to non-responders, responders exhibited increased hip adduction excursion at baseline (p = 0.02) and trended towards attending more training sessions (p = 0.07) and participating in soccer and not basketball (p = 0.07). Responders also showed greater improvements in hip flexion angles (p = 0.02) and moments (p < 0.001), and knee abduction angles (p < 0.001) and excursions (p = 0.001). There were no significant differences in age or experience with prior injury prevention programs (n.s.). CONCLUSIONS: After an ACL-IPP, athletes that exhibit the greatest reduction in knee abduction moments exhibit greater hip adduction excursion at baseline and show corresponding improvements in hip flexion and knee abduction kinematics and hip flexion moments. These results can help clinicians prospectively identify individuals that may not respond to an ACL-IPP and target individualized training for those at risk of injury. LEVEL OF EVIDENCE: I. CLINICAL TRIAL REGISTRATION NUMBER: Clinicaltrials.gov NCT02530333.


Assuntos
Lesões do Ligamento Cruzado Anterior/prevenção & controle , Atletas , Basquetebol/lesões , Articulação do Quadril/fisiopatologia , Articulação do Joelho/fisiopatologia , Movimento/fisiologia , Futebol/lesões , Adolescente , Lesões do Ligamento Cruzado Anterior/fisiopatologia , Fenômenos Biomecânicos , Feminino , Humanos , Fatores de Risco , Adulto Jovem
8.
J Appl Biomech ; 34(1): 65-75, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28952871

RESUMO

Vertical stiffness may contribute to lower-extremity injury risk; however, it is unknown whether athletes with different stiffness levels display differences in biomechanics. This study compared differences in biomechanics between female athletes (n = 99) with varying stiffness levels during a repetitive, single-leg, vertical hopping task. Vertical stiffness was calculated as the ratio of peak vertical ground-reaction force to maximum center-of-mass displacement. Tertiles were established using stiffness values, and separate 1-way ANOVAs were used to evaluate between-group differences. Stance times decreased, and flight times, ground-reaction force, and stiffness increased, from the low- to high-stiffness group (P < .050). The high-stiffness group displayed: (1) greater lateral trunk flexion (P = .009) and lesser hip adduction (P = .022) at initial ground contact compared to the low- and moderate-stiffness groups, respectively; (2) lesser peak hip adduction compared to the low-stiffness group (P = .040); (3) lesser lateral trunk-flexion (P = .046) and knee-flexion (P = .010) excursion compared to the moderate- and low-stiffness groups, respectively; and (4) greater peak hip-flexion (P = .001), ankle-dorsiflexion (P = .002), and ankle-eversion (P = .038) moments compared to the low-stiffness group. A wide range of variability in stiffness exists within a relatively homogenous population. Athletes with varying stiffness levels display biomechanical differences that may help identify the potential mechanism(s) by which stiffness contributes to injury risk.


Assuntos
Atletas , Fenômenos Biomecânicos/fisiologia , Extremidade Inferior/fisiologia , Movimento/fisiologia , Adolescente , Basquetebol/fisiologia , Feminino , Humanos , Amplitude de Movimento Articular/fisiologia , Futebol/fisiologia
9.
J Sport Rehabil ; 27(3): 213-217, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28338388

RESUMO

CONTEXT: Hip-focused interventions are aimed to decrease frontal plane knee loading related to anterior cruciate ligament injuries. Whether a preferred hip landing strategy decreases frontal plane knee loading is unknown. OBJECTIVE: To determine if a preferred hip landing strategy during a drop vertical jump (DVJ) is utilized during a single-leg landing (SLL) task and whether differences in frontal plane knee loading are consistent between a DVJ and an SLL task. DESIGN: Descriptive laboratory study. SETTING: Research laboratory. PARTICIPANTS: Twenty-three collegiate, female soccer players. MAIN OUTCOME MEASURES: Participants were dichotomized into a hip (HIP; n = 9) or knee/ankle (KA; n = 14) strategy group based on the percentage distribution of each lower extremity joint relative to the summated moment (% distribution) during the DVJ. Separate 1-way analysis of variances examined the differences in joint-specific % distribution and external knee abduction moment between the HIP and KA groups. RESULTS: The HIP group had significantly greater % distribution of hip moment and less % distribution of knee moment compared with the KA group during the DVJ and SLL. External knee abduction moment was also significantly less in the HIP group compared with the KA group during the DVJ. CONCLUSIONS: Female soccer athletes who land with a preferred hip strategy during a DVJ also land with a preferred hip strategy during an SLL. The preferred hip strategy also resulted in less external knee abduction moments during the DVJ. CLINICAL RELEVANCE: Targeting the neuromuscular control of the hip extensor may be useful in reducing risk of noncontact anterior cruciate ligament injuries.


Assuntos
Articulação do Quadril/fisiologia , Articulação do Joelho/fisiologia , Futebol , Adolescente , Articulação do Tornozelo/fisiologia , Atletas , Fenômenos Biomecânicos , Feminino , Humanos , Amplitude de Movimento Articular , Adulto Jovem
10.
BMC Musculoskelet Disord ; 18(1): 71, 2017 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-28173788

RESUMO

BACKGROUND: Anterior cruciate ligament (ACL) injuries in female athletes lead to a variety of short- and long-term physical, financial, and psychosocial ramifications. While dedicated injury prevention training programs have shown promise, ACL injury rates remain high as implementation has not become widespread. Conventional prevention programs use a combination of resistance, plyometric, balance and agility training to improve high-risk biomechanics and reduce the risk of injury. While many of these programs focus on reducing knee abduction load and posture during dynamic activity, targeting hip extensor strength and utilization may be more efficacious, as it is theorized to be an underlying mechanism of injury in adolescent female athletes. Biofeedback training may complement traditional preventive training, but has not been widely studied in connection with ACL injuries. We hypothesize that biofeedback may be needed to maximize the effectiveness of neuromuscular prophylactic interventions, and that hip-focused biofeedback will improve lower extremity biomechanics to a larger extent than knee-focused biofeedback during dynamic sport-specific tasks and long-term movement strategies. METHODS: This is an assessor-blind, randomized control trial of 150 adolescent competitive female (9-19 years) soccer players. Each participant receives 3x/week neuromuscular preventive training and 1x/week biofeedback, the mode depending on their randomization to one of 3 biofeedback groups (hip-focused, knee-focused, sham). The primary aim is to assess the impact of biofeedback training on knee abduction moments (the primary biomechanical predictor of future ACL injury) during double-leg landings, single-leg landings, and unplanned cutting. Testing will occur immediately before the training intervention, immediately after the training intervention, and 6 months after the training intervention to assess the long-term retention of modified biomechanics. Secondary aims will assess performance changes, including hip and core strength, power, and agility, and the extent to which maturation effects biofeedback efficacy. DISCUSSION: The results of the Real-time Optimized Biofeedback Utilizing Sport Techniques (ROBUST) trial will help complement current preventive training and may lead to clinician-friendly methods of biofeedback to incorporate into widespread training practices. TRIAL REGISTRATION: Date of publication in ClinicalTrials.gov: 20/04/2016. ClinicalTrials.gov Identifier: NCT02754700 .


Assuntos
Lesões do Ligamento Cruzado Anterior/reabilitação , Biorretroalimentação Psicológica/métodos , Sistemas Computacionais , Terapia por Exercício/métodos , Futebol/lesões , Adolescente , Lesões do Ligamento Cruzado Anterior/diagnóstico , Lesões do Ligamento Cruzado Anterior/etiologia , Fenômenos Biomecânicos/fisiologia , Criança , Feminino , Humanos , Estudos Prospectivos , Método Simples-Cego , Futebol/fisiologia , Adulto Jovem
11.
J Appl Biomech ; 33(1): 76-79, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27705063

RESUMO

Athletic individuals may differ in body segment inertial parameter (BSIP) estimates due to differences in body composition, and this may influence calculation of joint kinetics. The purposes of this study were to (1) compare BSIPs predicted by the method introduced by de Leva1 with DXA-derived BSIPs in collegiate female soccer players, and (2) examine the effects of these BSIP estimation methods on joint moment and power calculations during a drop vertical jump (DVJ). Twenty female NCAA Division I soccer players were recruited. BSIPs of the shank and thigh (mass, COM location, and radius of gyration) were determined using de Leva's method and analysis of whole-body DXA scans. These estimates were used to determine peak knee joint moments and power during the DVJ. Compared with DXA, de Leva's method located the COM more distally in the shank (P = .008) and more proximally in the thigh (P < .001), and the radius of gyration of the thigh to be further from the thigh COM (P < .001). All knee joint moment and power measures were similar between methods. These findings suggest that BSIP estimation may vary between methods, but the impact on joint moment calculations during a dynamic task is negligible.


Assuntos
Aceleração , Algoritmos , Composição Corporal/fisiologia , Modelos Biológicos , Futebol/fisiologia , Torque , Absorciometria de Fóton , Adulto , Simulação por Computador , Feminino , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
J Appl Biomech ; 33(2): 153-159, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27918689

RESUMO

Virtual environments with real-time feedback can simulate extrinsic goals that mimic real life conditions. The purpose was to compare jump performance and biomechanics with a physical overhead goal (POG) and with a virtual overhead goal (VOG). Fourteen female subjects participated (age: 18.8 ± 1.1 years, height: 163.2 ± 8.1 cm, weight 63.0 ± 7.9 kg). Sagittal plane trunk, hip, and knee biomechanics were calculated during the landing and take-off phases of drop vertical jump with different goal conditions. Repeated-measures ANOVAs determined differences between goal conditions. Vertical jump height displacement was not different during VOG compared with POG. Greater hip extensor moment (P < .001*) and hip angular impulse (P < .004*) were found during VOG compared with POG. Subjects landed more erect with less magnitude of trunk flexion (P = .002*) during POG compared with VOG. A virtual target can optimize jump height and promote increased hip moments and trunk flexion. This may be a useful alternative to physical targets to improve performance during certain biomechanical testing, screening, and training conditions.


Assuntos
Desempenho Atlético/fisiologia , Basquetebol/fisiologia , Treinamento com Simulação de Alta Fidelidade/métodos , Perna (Membro)/fisiologia , Condicionamento Físico Humano/métodos , Condicionamento Físico Humano/fisiologia , Interface Usuário-Computador , Adolescente , Feminino , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
J Sport Rehabil ; 26(5): 396-405, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27632880

RESUMO

CONTEXT: Excessive knee valgus and tibial external rotation relative to the femur during weight bearing motions, such as jump-landing, reportedly increases the risk of developing chronic knee pain, such as patellofemoral pain. Excessive deviations from normal ranges of several static lower extremity alignment measures and dynamic hip motions may also increase the risks for patellofemoral pain. OBJECTIVE: To determine the relationship between lower extremity alignments and hip motions to frontal and transverse plane knee motions during double-leg landings. DESIGN: Correlational study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: 69 healthy, competitive athletes (27 men, 42 women; height, 166.5 ± 9.5 cm; weight, 61.3 ± 9.9 kg; age, 20.7 ± 1.0 y) participated in this study. INTERVENTIONS: Prone and supine hip version, quadriceps angle, and tibiofemoral angle were measured. Frontal and transverse knee and hip angles at peak knee extensor moment during landing were calculated. MAIN OUTCOME MEASURES: 2 separate stepwise multiple regression analyses were conducted to predict frontal and transverse plane knee motions using 4 static lower extremity alignment measures and hip motions. RESULTS: Greater hip adduction and prone hip anteversion, and lesser hip internal rotation and supine hip anteversion, were related to greater knee valgus motions (R2 = .475, P < .01). Greater hip adduction was related to greater knee external rotation (R2 = .205, P < .01). CONCLUSIONS: Some targeted static lower extremity alignments and hip motions are associated with frontal and transverse knee motions. However, stronger relationships of hip motions with knee motions than static lower extremity alignments provided evidence that improving hip movements may help improve patellofemoral pain in those with lower extremity malalignments.


Assuntos
Articulação do Quadril/fisiologia , Articulação do Joelho/fisiologia , Atletas , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Movimento , Rotação , Adulto Jovem
14.
J Sport Rehabil ; 26(5): 358-364, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27632866

RESUMO

CONTEXT: Risk of anterior cruciate ligament (ACL) injuries in young female athletes increases with age, appearing to peak during maturation. Changes in hip muscle strength and range of motion (ROM) during this time may contribute to altered dynamic movement patterns that are known to increase risk of ACL injuries. Understanding the longitudinal changes in hip strength and ROM is needed to develop appropriate interventions to reduce the risk of ACL injuries. OBJECTIVE: To examine the longitudinal changes in hip strength and ROM in female youth soccer players. DESIGN: Longitudinal descriptive study. SETTING: Field setting. PARTICIPANTS: 14 female youth soccer athletes (14.1 ± 1.1 y, 165.8 ± 5.3 cm, 57.5 ± 9.9 kg) volunteered as part of a multiyear risk factor screening project. MAIN OUTCOME MEASURES: Clinical measures of hip strength and ROM were collected annually over 3 consecutive years. Passive hip internal rotation (IR), external rotation (ER), abduction (ABD), and adduction (ADD) ROM were measured with a digital inclinometer. Isometric hip ABD and extension (EXT) strength were evaluated using a hand-held dynamometer. Separate repeated-measures ANOVAs compared hip strength and ROM values across 3 consecutive years (P < .05). RESULTS: As youth female soccer players increased in age, there were no changes in normalized hip ABD (P = .830) or EXT strength (P = .062) across 3 consecutive years. Longitudinal changes in hip ROM were observed with increases in hip IR (P = .001) and ABD (P < .001), while hip ADD (P = .009) and ER (P < .001) decreased. CONCLUSIONS: Anatomical changes at the hip occur as youth female soccer players increase in age. While there are no changes in hip strength, there is an increase in hip IR and ABD ROM with a concomitant decrease in hip ER and ADD ROM. The resulting asymmetries in hip ROM may decrease the activation and force producing capabilities of the hip muscles during dynamic activities, contributing to altered lower extremity mechanics known to increase the risk of ACL injuries.


Assuntos
Lesões do Ligamento Cruzado Anterior/prevenção & controle , Quadril/fisiologia , Força Muscular , Amplitude de Movimento Articular , Futebol , Adolescente , Atletas , Fenômenos Biomecânicos , Feminino , Humanos , Músculo Esquelético/fisiologia , Projetos Piloto , Rotação
15.
Opt Express ; 23(17): 22667-75, 2015 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-26368235

RESUMO

We demonstrate a significant resolution enhancement beyond the conventional limit in multiphoton microscopy (MPM) using saturated excitation of fluorescence. Our technique achieves super-resolved imaging by temporally modulating the excitation laser-intensity and demodulating the higher harmonics from the saturated fluorescence signal. The improvement of the lateral and axial resolutions is measured on a sample of fluorescent microspheres. While the third harmonic already provides an enhanced resolution, we show that a further improvement can be obtained with an appropriate linear combination of the demodulated harmonics. Finally, we present in vitro imaging of fluorescent microspheres incorporated in HeLa cells to show that this technique performs well in biological samples.

16.
J Strength Cond Res ; 29(9): 2465-73, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26313573

RESUMO

Understanding how neuromuscular factors that are associated with lower extremity injury risk, such as landing kinematics, muscle strength, and flexibility, change as children mature may enhance age-specific recommendations for injury prevention programs. The purpose of this study was to compare these factors in prepubertal, pubertal, and postpubertal male and female athletes. Subjects were classified on maturation stage (prepubertal: 16 males, 15 females, age: 9 ± 1 years; pubertal: 13 males, 12 females, age: 12 ± 3 years; postpubertal: 30 males, 27 females, age: 16 ± 2 years). Researchers measured lower extremity isometric muscle strength and flexibility and evaluated kinematics and vertical ground reaction forces (VGRFs) during a jump-landing task. Three-dimensional kinematics at initial contact (IC), joint displacements, and peak VGRF were calculated. Separate multivariate analyses of variance were performed to evaluate sex and maturation differences (α ≤ 0.05). Postpubertal females landed with less knee flexion at IC (p = 0.006) and demonstrated lower knee extension strength (p = 0.01) than prepubertal and pubertal females. Postpubertal males landed with less hip adduction displacement (postpubertal males = 12.53 ± 6.15°, prepubertal males = 18.84 ± 7.47°; p = 0.04) and less peak VGRF (postpubertal males = 1.53 ± 0.27% body weight [BW], prepubertal males = 1.99 ± 0.32% BW; p = 0.03) compared with prepubertal males. These findings suggest encouraging sagittal plane absorption and decreasing frontal plane motion at the hip, whereas maintaining quadriceps strength may be important for reducing injury risk in postpubertal athletes.


Assuntos
Força Muscular/fisiologia , Desempenho Psicomotor/fisiologia , Caracteres Sexuais , Maturidade Sexual/fisiologia , Adolescente , Traumatismos em Atletas/etiologia , Traumatismos em Atletas/prevenção & controle , Fenômenos Biomecânicos , Criança , Estudos Transversais , Feminino , Humanos , Extremidade Inferior/fisiologia , Masculino , Análise Multivariada , Distribuição Aleatória , Fatores Sexuais
17.
18.
Int J Emerg Med ; 17(1): 90, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39014326

RESUMO

BACKGROUND: Dengue is the most common arboviral illness reported globally, endemic to most tropical and sub-tropical regions of the world. Dengue Shock Syndrome is a rare complication of severe Dengue infection resulting in haemorrhagic complications and refractory hypotension. We report on a case of severe dengue diagnosed in a patient with major trauma and illustrate some of the potential challenges and considerations in the clinical management of such cases. CASE PRESENTATION: A 49-year-old female presented following a road trauma incident with multiple abdominal injuries requiring urgent laparotomy. Her recovery in Intensive Care Unit was complicated by the development of Dengue Shock Syndrome characterised by a falling haemoglobin and platelet count, multiorgan dysfunction and prolonged hospital stay. CONCLUSIONS: Dengue Shock Syndrome may complicate fluid management and bleeding control in major trauma cases. Awareness of Dengue, particularly in endemic areas and returned travellers may help facilitate early diagnosis and management of complications.

19.
Front Med (Lausanne) ; 11: 1345698, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38695034

RESUMO

Background: Antimicrobial Stewardship Programs (ASP) have been applied widely in high-resource countries to prevent surgical site infections (SSI). Evidence favoring ASP interventions (ASPi) in gastrointestinal surgeries from low and middle-income countries has been limited, especially in antimicrobial prophylaxis. We aimed to investigate this gap at a Vietnamese tertiary hospital. Methods: We conducted a retrospective cohort study on patients undergoing clean-contaminated surgeries in 2015 who received standard of care (SoC) or SoC + ASPi. Primary outcome was 30-day SSI incidence. Secondary outcomes included length of stay (LoS) after surgery (days), cost of antibiotics, and cost of treatment (USD). Results were controlled for multiplicity and reported with treatment effect and 95% confidence interval (95%CI). A predictive model was built and cross-validated to detect patients at high risk of SSI. Results: We included 395 patients for analysis (48.1% being female, mean age 49.4 years). Compared to patients receiving SoC, those with SoC + ASPi had a lower incidence of 30-day SSI (-8.8, 95%CI: -16.0 to -1.6, p = 0.042), shorter LoS after surgery (-1.1 days, 95%CI: -1.8 to -0.4, p = 0.004), and lower cost of antibiotics (-37.3 USD, 95%CI: -59.8 to -14.8, p = 0.012) and treatment (-191.1 USD, 95%CI: -348.4 to -33.8, p = 0.042). We estimated that by detecting patients at high risk of SSI with the predictive model and providing prophylactic measures, we could save 398120.7 USD per 1,000 cases of SSI. Conclusion: We found that ASPi were associated with a reduction in risks of SSI, hospital stays, and cost of antibiotics/treatment in a Vietnamese tertiary hospital.

20.
RSC Adv ; 13(34): 24038-24052, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37577094

RESUMO

The development of photocatalysts that can utilize the entire solar spectrum is crucial to achieving efficient solar energy conversion. The utility of the benchmark photocatalyst, TiO2, is limited only to the UV region due to its large bandgap. Extending the light harvesting properties across the entire spectrum is paramount to enhancing solar photocatalytic performance. In this work, we developed low bandgap TiO2/conjugated polymer nanostructures which exhibit full spectrum activity for efficient H2 production. The highly mesoporous structure of the nanostructures together with the photosensitizing properties of the conjugated polymer enabled efficient solar light activity. The mesoporous TiO2 nanostructures calcined at 550 °C exhibited a defect-free anatase crystalline phase with traces of brookite and high surface area, resulting in the best performance in hydrogen production (5.34 mmol g-1 h-1) under sunlight simulation. This value is higher not only in comparison to other TiO2-based catalysts but also to other semiconductor materials reported in the literature. Thus, this work provides an effective strategy for the construction of full spectrum active nanostructured catalysts for enhanced solar photocatalytic hydrogen production.

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