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1.
J Ind Microbiol Biotechnol ; 50(1)2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-37960978

RESUMO

Gas chromatography-tandem mass spectrometry with electron ionization (GC-EI-MS/MS) provides rich information on stable-isotope labeling for 13C-metabolic flux analysis (13C-MFA). To pave the way for the routine application of tandem MS data for metabolic flux quantification, we aimed to compile a comprehensive library of GC-EI-MS/MS fragments of tert-butyldimethylsilyl (TBDMS) derivatized proteinogenic amino acids. First, we established an analytical workflow that combines high-resolution gas chromatography-quadrupole time-of-flight mass spectrometry and fully 13C-labeled biomass to identify and structurally elucidate tandem MS amino acid fragments. Application of the high-mass accuracy MS procedure resulted into the identification of 129 validated precursor-product ion pairs of 13 amino acids with 30 fragments being accepted for 13C-MFA. The practical benefit of the novel tandem MS data was demonstrated by a proof-of-concept study, which confirmed the importance of the compiled library for high-resolution 13C-MFA. ONE SENTENCE SUMMARY: An analytical workflow that combines high-resolution mass spectrometry (MS) and fully 13C-labeled biomass to identify and structurally elucidate tandem MS amino acid fragments, which provide positional information and therefore offering significant advantages over traditional MS to improve 13C-metabolic flux analysis.


Assuntos
Escherichia coli , Espectrometria de Massas em Tandem , Espectrometria de Massas em Tandem/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Escherichia coli/metabolismo , Isótopos de Carbono/análise , Isótopos de Carbono/metabolismo , Análise do Fluxo Metabólico/métodos , Aminoácidos/metabolismo
2.
Scand J Med Sci Sports ; 32(5): 924-932, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35108419

RESUMO

OBJECTIVE: Hip and groin pain is highly prevalent in sub-elite Gaelic Athletic Association (GAA) athletes, but its prevalence at the elite level is unknown. The aims of this study were to report hip and groin pain prevalence in elite male athletes, to report changes in Copenhagen Hip and Groin Outcome Score (HAGOS) across two seasons and to assess if previous hip and groin pain or pre-season HAGOS could predict future hip and groin pain. METHODS: During the 2017 and 2018 pre-season male Gaelic Players Association (GPA) playing members were invited to complete two questionnaires. The first questionnaire collected demographic information including age, GAA code played (Gaelic football or Hurling) and prevalence of hip and groin pain in the previous season. The second questionnaire was the HAGOS. Step-wise logistic regression models were fitted to HAGOS subscales, to examine if pre-season HAGOS subscale scores could predict future hip and groin pain. RESULTS: The prevalence of hip and groin pain across the elite GAA cohort was 38%. Hip and groin pain in the previous season was the strongest predictor of future hip and groin pain (r2 =0.19, AUC=0.73, 95% CI 1.76-2.27) whereas pre-season HAGOS subscale scores had limited and no additional predictive ability (AUC 0.05-0.18). CONCLUSIONS: Hip and groin pain prevalence is high in elite male GAA, with one in three athletes reporting pain. Previous season hip and groin pain is the strongest predictor of future hip and groin pain, while pre-season HAGOS scores have limited ability to predict future hip and groin pain.


Assuntos
Virilha , Quadril , Humanos , Masculino , Dor/epidemiologia , Prevalência , Estações do Ano
3.
J Sports Sci ; 40(17): 1885-1900, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36093680

RESUMO

Injury assessment during sporting collisions requires estimation of the associated kinematics. While marker-based solutions are widely accepted as providing accurate and reliable measurements, setup times are lengthy and it is not always possible to outfit athletes with restrictive equipment in sporting situations. A new generation of markerless motion capture based on deep learning techniques holds promise for enabling measurement of movement in the wild. The aim of this work is to evaluate the performance of a popular deep learning model "out of the box" for human pose estimation, on a dataset of ten staged rugby tackle movements performed in a marker-based motion capture laboratory with a system of three high-speed video cameras. An analysis of the discrepancy between joint positions estimated by the marker-based and markerless systems shows that the deep learning approach performs acceptably well in most instances, although high errors exist during challenging intervals of heavy occlusion and self-occlusion. In total, 75.6% of joint position estimates are found to have a mean absolute error (MAE) of less than or equal to 25 mm, 17.8% with MAE between 25 and 50 mm and 6.7% with MAE greater than 50 mm. The mean per joint position error is 47 mm.


Assuntos
Aprendizado Profundo , Esportes , Humanos , Movimento (Física) , Fenômenos Biomecânicos , Movimento
4.
J Strength Cond Res ; 36(3): 772-780, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-32058359

RESUMO

ABSTRACT: Ó Catháin, CP, Richter, C, and Moran, K. Can directed compliant running reduce the magnitude of variables associated with the development of running injuries? J Strength Cond Res 36(3): 772-780, 2022-Running is one of the most popular modes of activity worldwide and provides numerous health benefits. However, impact forces associated with the foot contacting the ground have been implicated in the development of running related injuries. As such, previous studies have used various methods to alter running to reduce the magnitude of these impact forces. However, it is unclear what kinematic changes facilitate this reduced loading or how loading further up the body changes. In this study, verbal direction was used to teach subjects to run with a more compliant running technique. Kinetic and kinematics characteristics of each subjects "normal" running technique and new "compliant technique" were measured in a fatigued and unfatigued state. Energy expenditure of each running style was also measured. Verbally directed compliant running significantly decreased (17%) vertical ground reaction force impact peaks, sacral (41%) and head (28%) impact accelerations, and increased energy expenditure (21%), in comparison with normal running. Findings suggest that verbally directed compliant running may reduce the magnitude of variables associated with the development of running injuries.


Assuntos
Corrida , Aceleração , Fenômenos Biomecânicos , , Humanos , Extremidade Inferior , Corrida/lesões
5.
Scand J Med Sci Sports ; 31(4): 839-847, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33098142

RESUMO

Athletic groin pain (AGP) is a chronic, painful condition which is prevalent in players of field sports that require rapid changes of direction. Following successful rehabilitation, systematic changes have been observed in the kinetics and kinematics of pre-planned change of direction maneuvers, providing insight into potential foci for rehabilitation monitoring and for the assessment of interventions. However, changing direction in field sports is often reactive rather than pre-planned, and it is not known whether such post-rehabilitation changes are seen in reactive maneuvers. We analyzed the stance phase kinetics and kinematics of a 90° reactive cutting maneuver in 35 AGP patients before and after a successful exercise intervention program. Following the intervention, transverse plane rotation of the pelvis toward the intended direction of travel increased, and the body center of mass was positioned more anteriorly relative to the center of pressure. Ankle dorsiflexion also increased, and participants demonstrated greater ankle plantar flexor internal moment and power during the second half of stance. These findings provide insight into mechanical variables of potential importance in AGP, as identified during a maneuver based on a common sporting task.


Assuntos
Traumatismos em Atletas/reabilitação , Virilha/lesões , Movimento/fisiologia , Corrida/fisiologia , Adulto , Fenômenos Biomecânicos , Humanos , Cinética , Masculino , Adulto Jovem
6.
J Strength Cond Res ; 35(6): 1715-1723, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30664108

RESUMO

ABSTRACT: Welch, N, Richter, C, Franklyn-Miller, A, and Moran, K. Principal component analysis of the biomechanical factors associated with performance during cutting. J Strength Cond Res 35(6): 1715-1723, 2021-The main aim of the current study was to investigate the relationship between kinematic variables in cutting and performance outcome across different angled cuts through the use of principal component analysis and permutation testing. Twenty-five male intercounty Gaelic football players (23.5 ± 4.2 years, 183 ± 6 cm, and 83 ± 6.9 kg) participated in the study. Three-dimensional motion capture was used to perform a biomechanical analysis of 110 and 45° cutting tasks. Principal component analysis and permutation testing revealed one principal component within the 45° cut (r = 0.26) and 2 principal components within the 110° (r = 0.66 and 0.27) cut that consistently correlated with performance outcome. Within the 45° cut, the identified principal component was interpreted as relating to performance cues of maintaining a low center of mass during the concentric phase, using a shorter ground contact time, resisting a reduction in lateral center of mass to ankle and knee distance in the eccentric phase, and using faster and larger extensions of the hip and knee. Within the 110° cut, the first identified principal component was interpreted as relating to performance cues of maintaining a low center of mass during the concentric phase, using a shorter ground contact time, resisting a reduction in lateral center of mass to ankle and knee distance in the eccentric phase, and resisting hip flexion then using hip extension. The second principal component was interpreted as relating to a performance cue of leaning in the direction of the cut.


Assuntos
Desempenho Atlético , Movimento , Humanos , Masculino , Fenômenos Biomecânicos , Articulação do Joelho , Análise de Componente Principal , Esportes de Equipe , Desempenho Atlético/fisiologia
7.
J Strength Cond Res ; 35(7): 1848-1855, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30741857

RESUMO

ABSTRACT: Welch, N, Richter, C, Moran, K, and Franklyn-Miller, A. Principal component analysis of the associations between kinetic variables in cutting and jumping, and cutting performance outcome. J Strength Cond Res 35(7): 1848-1855, 2021-The primary aim of this study was to determine which features within the ground reaction force (GRF) trace during cutting are related to performance outcome in different angled cuts. The secondary aim was to understand the relationship between GRF features in a series of maximum strength, explosive strength, and reactive strength tests, and cutting performance outcome. Twenty-five male intercounty Gaelic football players (23.5 ± 4.2 years, 183 ± 6 cm, and 83 ± 6.9 kg) participated in the study. Subjects completed 110 and 45° cutting tasks, single leg squat jumps, drop landings, drop jumps, and isometric midthigh pulls. A principal component (PC) analysis and simulation approach were applied to the data and correlations between PCs and cutting performance outcome measured. Lower vertical to horizontal impulse ratios (r = -0.70 to -0.46) in both cuts and greater forces over the first 50 ms of ground contact (r = -0.44) in the 110° cut correlated with enhanced cutting performance outcomes. Greater reactive strength index and height in the drop jump (r = -0.51 and -0.54) and greater impulses over the first 25 ms of ground contact in the drop landing (r = 0.49 and 0.70) correlated with enhanced cutting performance outcomes. These results highlight the importance of greater horizontal and rapid force production in cutting and greater reactive strength qualities to enhance cutting performance.


Assuntos
Desempenho Atlético , Esportes de Equipe , Humanos , Masculino , Cinética , Postura , Análise de Componente Principal , Desempenho Atlético/fisiologia
8.
Sensors (Basel) ; 20(3)2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32033123

RESUMO

The validity of an inertial sensor-based motion capture system (IMC) has not been examined within the demands of a sports-specific field movement test. This study examined the validity of an IMC during a field test (VU®) by comparing it to an optical marker-based motion capture system (MMC). Expected accuracy and precision benchmarks were computed by comparing the outcomes of a linear and functional joint fitting model within the MMC. The kinematics from the IMC in sagittal plane demonstrated correlations (r2) between 0.76 and 0.98 with root mean square differences (RMSD) < 5, only the knee bias was within the benchmark. In the frontal plane, r2 ranged between 0.13 and 0.80 with RMSD < 10, while the knee and hip bias was within the benchmark. For the transversal plane, r2 ranged 0.11 to 0.93 with RMSD < 7, while the ankle, knee and hip bias remained within the benchmark. The findings indicate that ankle kinematics are not interchangeable with MMC, that hip flexion and pelvis tilt higher in IMC than MMC, while other measures are comparable to MMC. Higher pelvis tilt/hip flexion in the IMC can be explained by a one sensor tilt estimation, while ankle kinematics demonstrated a considerable level of disagreement, which is likely due to four reasons: A one sensor estimation, sensor/marker attachment, movement artefacts of shoe sole and the ankle model used.


Assuntos
Articulação do Tornozelo/fisiologia , Atletas , Articulação do Quadril/fisiologia , Articulação do Joelho/fisiologia , Volta ao Esporte , Sapatos , Adulto , Fenômenos Biomecânicos , Humanos , Masculino , Movimento , Pelve/fisiologia , Amplitude de Movimento Articular , Reprodutibilidade dos Testes
9.
Scand J Med Sci Sports ; 28(12): 2567-2578, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29972874

RESUMO

INTRODUCTION: Previous studies examining jump tasks after anterior cruciate ligament reconstruction (ACLR) have focused on performance measures without examining joint kinematic and kinetic variables. The aim of this study was to identify differences in biomechanical and performance measures between limbs across tests 9 months after surgery. METHODS: Four jump tests (double-leg drop jump (DLDJ), single-leg drop jump (SLDJ), single-leg hop for distance (SLHD) and hurdle hop (HH)) were carried out on 156 male subjects in a 3D motion capture laboratory 9 months after surgery. Statistical parametric mapping was used to identify differences in jump performance and biomechanical variables between limbs. RESULTS: Biomechanical measures were lower on the ACLR side across all four tests for internal knee valgus moment (effect size 0.78-0.96, knee internal rotation angle 0.59-0.73, and 0.60-0.83), respectively. [corrected].The timing of the largest difference between limbs was not at the same % stance between variables within a test or for any variable across tests. Large ES differences were observed in performance in the SLDJ (ES 0.73-0.81; LSI 78%) and small differences in the SLHD (ES 0.36; LSI 94%) between the limbs. CONCLUSION: Findings highlighted biomechanical differences between limbs which are consistent across jump tasks suggesting insufficient rehabilitation at 9 months post surgery. Results indicate that the SLDJ may identify greater performance deficits between limbs than SLHD, which may over-estimate rehabilitation status.


Assuntos
Tornozelo , Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior/reabilitação , Joelho , Amplitude de Movimento Articular , Adulto , Fenômenos Biomecânicos , Teste de Esforço , Quadril , Humanos , Masculino , Rotação , Adulto Jovem
10.
Br J Sports Med ; 52(16): 1054-1062, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29550754

RESUMO

BACKGROUND: Clinical assessments and rehabilitation in athletic groin pain (AGP) have focused on specific anatomical structures and uniplanar impairments rather than whole body movement. OBJECTIVE: To examine the effectiveness of rehabilitation that targeted intersegmental control in patients with AGP and to investigate post rehabilitation changes in cutting biomechanics. METHODS: Two hundred and five patients with AGP were rehabilitated focusing on clinical assessment of intersegmental control, linear running and change of direction mechanics in this prospective case series. Hip and Groin Outcome Score (HAGOS) was the primary outcome measure. Secondary measures included pain-free return to play rates and times, pain provocation on squeeze tests and three-dimensional (3D) biomechanical analysis during a 110° cutting manoeuvre. RESULTS: Following rehabilitation, patients demonstrated clinically relevant improvements in HAGOS scores (effect size (ES): 0.6-1.7). 73% of patients returned to play pain-free at a mean of 9.9 weeks (±3.5). Squeeze test values also improved (ES: 0.49-0.68). Repeat 3D analysis of the cutting movement demonstrated reductions in ipsilateral trunk side flexion (ES: 0.79) and increased pelvic rotation in the direction of travel (ES: 0.76). Changes to variables associated with improved cutting performance: greater centre of mass translation in the direction of travel relative to centre of pressure (ES: 0.4), reduced knee flexion angle (ES: 0.3) and increased ankle plantar flexor moment (ES: 0.48) were also noted. CONCLUSIONS: Rehabilitation focused on intersegmental control was associated with improved HAGOS scores, high rates of pain-free return to sporting participation and biomechanical changes associated with improved cutting performance across a range of anatomical diagnoses seen in AGP.


Assuntos
Traumatismos em Atletas/reabilitação , Virilha/lesões , Dor Pélvica/reabilitação , Adulto , Tornozelo , Fenômenos Biomecânicos , Humanos , Joelho , Masculino , Movimento , Estudos Prospectivos , Amplitude de Movimento Articular , Volta ao Esporte , Corrida , Adulto Jovem
11.
J Sports Sci ; 36(8): 889-900, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28650739

RESUMO

We investigated the effects of high intensity, intermittent exercise (HIIP) and anticipation on trunk, pelvic and lower limb biomechanics during a crossover cutting manoeuvre. Twenty-eight male, varsity athletes performed crossover cutting manoeuvres in anticipated and unanticipated conditions pre- and post-HIIP. Kinematic and kinetic variables were captured using a motion analysis system. Statistical parametric mapping (repeated-measures ANOVA) was used to identify differences in biomechanical patterns. Results demonstrated that both unanticipation and fatigue (HIIP) altered the biomechanics of the crossover cutting manoeuvre, whereas no interactions effects were observed. Unanticipation resulted in less trunk and pelvic side flexion in the direction of cut (d = 0.70 - 0.79). This led to increased hip abductor and external rotator moments and increased knee extensor and valgus moments with small effects (d = 0.24-0.42), potentially increasing ACL strain. The HIIP resulted in trivial to small effects only with a decrease in internal knee rotator and extensor moment and decreased knee power absorption (d = 0.35), reducing potential ACL strain. The effect of trunk and hip control exercises in unanticipated conditions on the crossover cutting manoeuvre should be investigated with a view to refining ACL injury prevention programmes.


Assuntos
Antecipação Psicológica/fisiologia , Treinamento Intervalado de Alta Intensidade , Extremidade Inferior/fisiologia , Destreza Motora/fisiologia , Tronco/fisiologia , Tornozelo/fisiologia , Ligamento Cruzado Anterior/fisiologia , Fenômenos Biomecânicos , Quadril/fisiologia , Humanos , Cinética , Joelho/fisiologia , Masculino , Pelve/fisiologia , Fatores de Risco , Estudos de Tempo e Movimento , Adulto Jovem
12.
J Strength Cond Res ; 32(6): 1583-1593, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29543702

RESUMO

Whyte, EF, Richter, C, O'Connor, S, and Moran, KA. Investigation of the effects of high-intensity, intermittent exercise and unanticipation on trunk and lower limb biomechanics during a side-cutting maneuver using statistical parametric mapping. J Strength Cond Res 32(6): 1583-1593, 2018-Anterior cruciate ligament (ACL) injuries frequently occur during side-cutting maneuvers when fatigued or reacting to the sporting environment. Trunk and hip biomechanics are proposed to influence ACL loading during these activities. However, the effects of fatigue and unanticipation on the biomechanics of the kinetic chain may be limited by traditional discrete point analysis. We recruited 28 male, varsity, Gaelic footballers (21.7 ± 2.2 years; 178.7 ± 14.6 m; 81.8 ± 11.4 kg) to perform anticipated and unanticipated side-cutting maneuvers before and after a high-intensity, intermittent exercise protocol (HIIP). Statistical parametric mapping (repeated-measures analysis of varience) identified differences in phases of trunk and stance leg biomechanics during weight acceptance. Unanticipation resulted in less trunk flexion (p < 0.001) and greater side flexion away from the direction of cut (p < 0.001). This led to smaller (internal) knee flexor and greater (internal) knee extensor (p = 0.002-0.007), hip adductor (p = 0.005), and hip external rotator (p = 0.007) moments. The HIIP resulted in increased trunk flexion (p < 0.001) and side flexion away from the direction of cut (p = 0.038), resulting in smaller (internal) knee extensor moments (p = 0.006). One interaction effect was noted demonstrating greater hip extensor moments in the unanticipated condition post-HIIP (p = 0.025). Results demonstrate that unanticipation resulted in trunk kinematics considered an ACL injury risk factor. A subsequent increase in frontal and transverse plane hip loading and sagittal plane knee loading was observed, which may increase ACL strain. Conversely, HIIP-induced trunk kinematic alterations resulted in reduced sagittal plane knee and subsequent ACL loading. Therefore, adequate hip and knee control is important during unanticipated side-cutting maneuvers.


Assuntos
Exercício Físico/fisiologia , Futebol Americano/fisiologia , Extremidade Inferior/fisiologia , Esforço Físico/fisiologia , Tronco/fisiologia , Suporte de Carga/fisiologia , Adulto , Lesões do Ligamento Cruzado Anterior/etiologia , Fenômenos Biomecânicos , Teste de Esforço , Articulação do Quadril/fisiologia , Humanos , Cinética , Articulação do Joelho/fisiologia , Masculino , Movimento , Músculo Esquelético/fisiologia , Rotação , Adulto Jovem
13.
J Sports Sci ; 35(15): 1538-1546, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27571390

RESUMO

An evaluation of a six-week Combined minimal footwear transition and gait-retraining combination vs. gait retraining only on impact characteristics and leg stiffness. Twenty-four trained male runners were randomly assigned to either (1) Minimalist footwear transition Combined with gait-retraining over a six-week period ("Combined" group; n = 12) examined in both footwear, or (2) a gait-retraining group only with no minimalist footwear exposure ("Control"; n = 12). Participants were assessed for loading rate, impact peak, vertical, knee and ankle stiffness, and foot-strike using 3D and kinetic analysis. Loading rate was significantly higher in the Combined group in minimal shoes in pre-tests compared to a Control (P ≤ 0.001), reduced significantly in the Combined group over time (P ≤ 0.001), and was not different to the Control group in post-tests (P = 0.16). The impact peak (P = 0.056) and ankle stiffness reduced in both groups (P = 0.006). Loading rate and vertical stiffness was higher in minimalist footwear than conventional running shoes both pre (P ≤ 0.001) and post (P = 0.046) the intervention. There has a higher tendency to non-rearfoot strike in both interventions, but more acute changes in the minimalist footwear. A Combined intervention can potentially reduce impact variables. However, higher loading rate initially in minimalist footwear may increase the risk of injury in this condition.


Assuntos
Marcha/fisiologia , Corrida/fisiologia , Sapatos , Adulto , Tornozelo/fisiologia , Fenômenos Biomecânicos , Desenho de Equipamento , Pé/fisiologia , Humanos , Joelho/fisiologia , Masculino , Fatores de Risco , Corrida/lesões , Suporte de Carga/fisiologia
14.
J Appl Biomech ; 30(2): 316-21, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24042053

RESUMO

The aim of this study is to propose a novel data analysis approach, an analysis of characterizing phases (ACP), that detects and examines phases of variance within a sample of curves utilizing the time, magnitude, and magnitude-time domains; and to compare the findings of ACP to discrete point analysis in identifying performance-related factors in vertical jumps. Twenty-five vertical jumps were analyzed. Discrete point analysis identified the initial-to-maximum rate of force development (P=.006) and the time from initial-to-maximum force (P=.047) as performance-related factors. However, due to intersubject variability in the shape of the force curves (ie, non-, uni- and bimodal nature), these variables were judged to be functionally erroneous. In contrast, ACP identified the ability to apply forces for longer (P<.038), generate higher forces (P<.027), and produce a greater rate of force development (P<.003) as performance-related factors. Analysis of characterizing phases showed advantages over discrete point analysis in identifying performance-related factors because it (i) analyses only related phases, (ii) analyses the whole data set, (iii) can identify performance-related factors that occur solely as a phase, (iv) identifies the specific phase over which differences occur, and (v) analyses the time, magnitude and combined magnitude-time domains.


Assuntos
Perna (Membro)/fisiologia , Movimento/fisiologia , Desempenho Atlético , Fenômenos Biomecânicos , Humanos , Masculino , Esforço Físico/fisiologia , Processamento de Sinais Assistido por Computador , Análise e Desempenho de Tarefas , Adulto Jovem
15.
J Appl Biomech ; 30(6): 732-6, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25010220

RESUMO

In functional principal component analysis (fPCA) a threshold is chosen to define the number of retained principal components, which corresponds to the amount of preserved information. A variety of thresholds have been used in previous studies and the chosen threshold is often not evaluated. The aim of this study is to identify the optimal threshold that preserves the information needed to describe a jump height accurately utilizing vertical ground reaction force (vGRF) curves. To find an optimal threshold, a neural network was used to predict jump height from vGRF curve measures generated using different fPCA thresholds. The findings indicate that a threshold from 99% to 99.9% (6-11 principal components) is optimal for describing jump height, as these thresholds generated significantly lower jump height prediction errors than other thresholds.


Assuntos
Interpretação Estatística de Dados , Pé/fisiologia , Movimento/fisiologia , Redes Neurais de Computação , Reconhecimento Automatizado de Padrão/métodos , Análise de Componente Principal , Análise e Desempenho de Tarefas , Adulto , Análise de Variância , Humanos , Masculino , Esforço Físico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estresse Mecânico
16.
J Appl Biomech ; 29(6): 763-8, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23549387

RESUMO

Although an authoritative panel recommended the use of ergometer rowing as a non-weight-bearing form of exercise for obese adults, the biomechanical characterization of ergometer rowing is strikingly absent. We examined the interaction between body mass index (BMI) relative to the lower extremity biomechanics during rowing in 10 normal weight (BMI 18-25), 10 overweight (BMI 25-30 kg·m⁻²), and 10 obese (BMI > 30 kg·m⁻²) participants. The results showed that BMI affects joint kinematics and primarily knee joint kinetics. The data revealed that high BMI leads to unfavorable knee joint torques, implying increased loads of the medial compartment in the knee joint that could be avoided by allowing more variable foot positioning on future designs of rowing ergometers.


Assuntos
Aceleração , Índice de Massa Corporal , Ergometria/métodos , Articulação do Joelho/fisiopatologia , Obesidade/fisiopatologia , Esforço Físico , Amplitude de Movimento Articular , Simulação por Computador , Terapia por Exercício/métodos , Feminino , Humanos , Masculino , Modelos Biológicos , Obesidade/reabilitação , Navios , Torque
17.
Sports Biomech ; 22(1): 91-101, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34323653

RESUMO

Classification algorithms determine the similarity of an observation to defined classes, e.g., injured or healthy athletes, and can highlight treatment targets or assess progress of a treatment. The primary aim was to cross-validate a previously developed classification algorithm using a different sample, while a secondary aim was to examine its ability to predict future ACL injuries. The examined outcome measure was 'healthy-limb' class membership probability, which was compared between a cohort of athletes without previous or future (No Injury) previous (PACL) and future ACL injury (FACL). The No Injury group had significantly higher probabilities than the PACL (p < 0.001; medium effect) and FACL group (p ≤ 0.045; small effect). The ability to predict group membership was poor for the PACL (area under curve [AUC]; 0.61

Assuntos
Lesões do Ligamento Cruzado Anterior , Traumatismos em Atletas , Humanos , Ligamento Cruzado Anterior , Traumatismos em Atletas/diagnóstico , Fenômenos Biomecânicos , Aprendizado de Máquina , Algoritmos
18.
Sci Med Footb ; 7(4): 374-383, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-35896059

RESUMO

PURPOSE: The purpose of this study was to assess the agreement between match-derived running load outputs; total distance (TD), high-speed running (HSR) and sprint distance (SPR) obtained by two optical tracking systems. METHODS: Data were collected from 31 elite footballers from the first team and under-21 squads of an English Premier League (EPL) football club across three competitive matches. One EPL game (game 2) and one under-21 Premier League game (game 3) were played at the team's home stadium and one EPL game (game 1) at an away venue. All matches were tracked concomitantly using eight colour cameras sampling at 10 Hz (PROZONE®) and six high-definition motion cameras sampling at 25 Hz (TRACAB®). RESULTS: TD displayed a perfect (r = 0.99) correlation while HSR and SPR displayed very large (r = 0.81 and r = 0.73) correlations between TRACAB® and PROZONE®. Mean biases were 5% for TD, -3% for HSR and 61% for SPR. Between games, mean biases for TD were 6% for game 1, and 5% for game 2 and game 3. For HSR, 9% for game 1, -5% for game 2 and 6% for game 3 and for SPR, 31% for game 1, 71% for game 2 and 84% for game 3. CONCLUSION: TD and HSR can be interchanged between PROZONE® and TRACAB®, to allow accurate interpretation between the two optical systems. PROZONE® overestimated SPR compared to the TRACAB®, with the magnitude of difference considered meaningful, altering interpretation of historical match outputs, sprint volume trends in the EPL and forecasts of the modern game.


Assuntos
Desempenho Atlético , Futebol Americano , Corrida , Movimento (Física)
19.
Biology (Basel) ; 12(4)2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37106731

RESUMO

(1) Background: Aging is linked to an altered immune response and metabolism. Inflammatory conditions, such as sepsis, COVID-19, and steatohepatitis are more prevalent in the elderly and steatosis is linked both to severe COVID-19 and sepsis. We hypothesized that aging is linked to a loss of endotoxin tolerance, which normally protects the host from excessive inflammation, and that this is accompanied by elevated levels of hepatic lipids. (2) Methods: An in vivo lipopolysaccharide (LPS) tolerance model in young and old mice was used and the cytokine serum levels were measured by ELISA. Cytokine and toll-like receptor gene expression was determined by qPCR in the lungs and the liver; hepatic fatty acid composition was assessed by GC-MS. (3) Results: The old mice showed a distinct potential for endotoxin tolerance as suggested by the serum cytokine levels and gene expression in the lung tissue. Endotoxin tolerance was less pronounced in the livers of the aged mice. However, the fatty acid composition strongly differed in the liver tissues of the young and old mice with a distinct change in the ratio of C18 to C16 fatty acids. (4) Conclusions: Endotoxin tolerance is maintained in advanced age, but changes in the metabolic tissue homeostasis may lead to an altered immune response in old individuals.

20.
Orthop J Sports Med ; 10(10): 23259671221125159, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36338351

RESUMO

Background: Athletic groin pain (AGP) can lead to altered movement patterns during rapid deceleration and acceleration. However, the effect of AGP on movement variability and loading patterns during such actions remains less clear. Purpose: To investigate, using a continuous lateral hurdle hop task, how movement variability and magnitude measures of 3-dimensional (3D) kinematic, kinetic, and vertical ground-reaction force (vGRF) variables are (1) affected by AGP (AGP vs uninjured controls [CON]) and (2) changed after successful rehabilitation (AGP prerehabilitation vs AGP postrehabilitation vs CON). Study Design: Controlled laboratory study. Methods: A total of 36 athletes diagnosed with AGP and 36 uninjured CON athletes matched on age (18-35 years), level (subelite), and type of sports played (multidirectional field sport) performed a continuous lateral hurdle hop test that involved 10 side-to-side hops over a 15-cm hurdle. The 3D joint kinematic, kinetic, and vGRF variables (total, eccentric, and concentric; ground contact time, peak force, and impulse; and eccentric rate of force development) were examined. The AGP and CON groups were tested at baseline, and the AGP group was retested after participants successfully completed a standardized, exercise-based rehabilitation program targeting intersegmental control. Results: There were no differences in baseline characteristics between the AGP (mean ± SD: age, 27.5 ± 4.8 years; height, 179.8 ± 6.3 cm; mass, 80.3 ± 7.1 kg) and CON (mean ± SD: age, 24.1 ± 4.5 years; height, 181.0 ± 5.8 cm; mass, 80.4 ± 8.2 kg) groups. At baseline, athletes with AGP demonstrated altered loading patterns in the vGRF (longer ground contact times, reduced peak force, and reduced rate of force development) compared with CON athletes, while no significant difference in any movement variability variables was evident. After rehabilitation, the athletes with AGP demonstrated significant changes in transverse and coronal plane hip and trunk kinematics, with no significant differences in vGRF variables compared with the CON group. Conclusion: The differences in baseline vGRF measures between the AGP and CON groups were no longer evident after athletes with AGP underwent rehabilitation. No differences in movement variability were evident between the AGP and CON groups, either before or after rehabilitation. Clinical Relevance: Rehabilitation programs should consider targeting intersegmental hip and trunk movement patterns to positively influence loading patterns in athletes with AGP.

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