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2.
Clin J Sport Med ; 31(3): 304-312, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31415020

RESUMO

OBJECTIVE: Fatigue due to game play is often cited as a factor in musculoskeletal injuries; however, it is unclear whether or not this view is supported by published research findings. Given the importance researchers and practitioners place on the potential effects of game play with respect to injury, it is important to understand what inferences can be drawn from the collective research in this realm. This meta-analysis will consider the time of season and segment of the game, as it relates anterior cruciate ligament (ACL), groin, and hamstring injury occurrence. DATA SOURCES: Database searches were run in PubMed, MEDLINE, SportDiscus, CINAHL, and Ausport, in addition to the inclusion of articles identified manually. STUDY SELECTION: Search terms were chosen to identify articles related to each of the 3 injuries of interest. There were no date limitations placed on the articles, as such, all published articles listed in the databases up to November 2017 were eligible for selection if they met the search criteria. DATA EXTRACTION: Initial searches yielded 1349 articles, and this was eventually reduced to 15 articles deemed suitable for inclusion in the meta-analysis, which provided 21 data sets. DATA SYNTHESIS: Comparing the first half with the second half of the season, there were no differences in ACL, groin, or hamstring injury occurrences [ACL: odds ratio (OR), 1.27; confidence interval (CI), 0.43-3.78, groin: OR, 1.79; CI, 0.63-5.06, and hamstring: OR, 1.16; CI, 0.88-1.53]. Similarly, there were no differences in injury occurrence between the first and second halves of the game for the ACL or hamstring injuries (ACL: OR, 0.43; CI, 0.47-7.92, hamstring: OR, 0.85; CI, 0.58-1.24). CONCLUSIONS: Findings from this meta-analysis determined that time in season or time in game does not influence risk of the ACL, groin, or hamstring injury. Commonly, many studies did not provide sufficient detail to be included in the meta-analysis. Consequently, it is recommended that future studies report data related to the timing of the injury within the season or game.


Assuntos
Lesões do Ligamento Cruzado Anterior , Traumatismos em Atletas/epidemiologia , Traumatismos da Perna , Estações do Ano , Lesões do Ligamento Cruzado Anterior/epidemiologia , Humanos , Traumatismos da Perna/epidemiologia
3.
PeerJ ; 8: e9366, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612890

RESUMO

Background: Quantifying lower-limb load and asymmetry during team sport match-play may be important for injury prevention and understanding performance. However, current analysis methods of lower-limb symmetry during match-play employ wearable microtechnology that may not be best suited to the task. A popular microtechnology is global positioning systems (GPS), which are torso worn. The torso location, and the summary workload measures calculated by GPS are not suited to the calculation of lower-limb load. Instead, research grade accelerometers placed directly on the lower-limb may provide better load information than GPS. This study proposes a new technique to quantify external mechanical load, and lower-limb asymmetry during on-field team sport play using inertial measurement units. Methods: Four professional rugby league players (Age: 23.4  ± 3.1 years; Height: 1.89  ± 0.05 m; Mass: 107.0  ± 12.9 kg) wore two accelerometers, one attached to each foot by the boot laces, during match simulations. Custom Matlab (R2017b, The Mathworks Inc, Natick, MA) code was used to calculate total time, area under the curve (AUC), and percentage of time (%Time) spent in seven acceleration categories (negative to very high, <0 g to >16 g), as well as minimum and maximum acceleration during match simulations. Lower-limb AUC and %Time asymmetry was calculated using the Symmetry Angle Equation, which does not require normalization to a reference leg. Results: The range of accelerations experienced across all participants on the left and right sides were 15.68-17.53 g, and 16.18-17.69 g, respectively. Clinically significant asymmetry in AUC and %Time was observed for all but one participant, and only in negative (<0 g) and very high accelerations (>16 g). Clinically significant AUC differences in very high accelerations ranged from 19.10%-26.71%. Clinically significant %Time differences in negative accelerations ranged from 12.65%-25.14%, and in very high accelerations from 18.59%-25.30%. All participants experienced the most AUC at very low accelerations (2-4 g), and the least AUC at very high accelerations (165.00-194.00 AU vs. 0.32-3.59 AU). The %Time results indicated that all participants spent the majority of match-play (73.82-92.06%) in extremely low (0-2 g) to low (4-6 g) acceleration intensities, and the least %Time in very high accelerations (0.01%-0.05%). Discussion: A wearable located on the footwear to measure lower-limb load and asymmetry is feasible to use during rugby league match-play. The location of the sensor on the boot is suited to minimize injury risk occurring from impact to the sensor. This technique is able to quantify external mechanical load and detect inter limb asymmetries during match-play at the source of impact and loading, and is therefore likely to be better than current torso based methods. The results of this study may assist in preparing athletes for match-play, and in preventing injury.

4.
Med Sci Sports Exerc ; 52(8): 1763-1769, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32102055

RESUMO

PURPOSE: This study aimed to characterize and evaluate female-specific physiological and perceptual responses during a load carriage walking task before and after a 10-wk physical training program. METHODS: Eleven recreationally active women (age, 21.5 ± 2.2 yr; stature, 1.66 ± 0.8 m; body mass, 64.4 ± 6.8 kg) completed a load carriage task (5 km at 5.5 km·h, wearing a 23-kg torso-borne vest) before and after a 10-wk physical training program. Physiological (i.e., maximal oxygen uptake, carbon dioxide production, respiratory exchange ratio (RER), breathing frequency, and pulmonary ventilation) and perceptual (i.e., rating of perceived exertion [RPE]) responses were collected during the load carriage task. Additional physical performance measures (i.e., push-ups, sit-ups, beep test, and isometric midthigh pull) were collected in a separate session before and after the 10-wk of training. RESULTS: Compared with before training, maximal oxygen uptake requirements reduced during the load carriage task (P < 0.05), whereas heart rate and RPE remained similar. RER reductions over the 5-km march indicated a shift toward fat utilization, with other physiological responses demonstrating an increased ability to sustain the metabolic demands of the load carriage task. Increases in push-up and isometric midthigh pull performance demonstrated improvements in upper-body muscular endurance and lower-body strength after the 10-wk training program (P < 0.05). CONCLUSIONS: During a standardized load carriage task, physiological and perceptual responses indicated physical adaptations to specific training in women. Although positive physiological responses were elicited, additional strategies (i.e., cognitive resilience training, female-specific vest design to reduce pain burden) to build load carriage task-specific resilience (perceptual responses) may be required.


Assuntos
Adaptação Fisiológica , Militares , Condicionamento Físico Humano/métodos , Suporte de Carga , Teste de Esforço , Feminino , Frequência Cardíaca , Humanos , Militares/psicologia , Força Muscular , Consumo de Oxigênio , Percepção/fisiologia , Esforço Físico/fisiologia , Análise e Desempenho de Tarefas , Caminhada/fisiologia , Adulto Jovem
5.
J Sports Sci ; 38(3): 248-255, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31726955

RESUMO

Accelerometers are often placed on the tibia to measure segmental accelerations, and external mechanical load during running. However, in applied sport settings it is sometimes preferable to place accelerometers on the dorsal foot to avoid tibial impact injuries. This study aimed to quantify the differences in accelerations measured at the dorsal foot compared with the distal tibia during running. Sixteen recreationally active participants performed a sprint protocol on a non-motorised treadmill. Accelerometers were positioned bilaterally on the medial tibia (TIBLeft and TIBRight), and bilateral dorsal foot surfaces (DORLeft and DORRight). Continuous acceleration signal waveform analysis was performed using one-dimensional statistical parametric mapping (1DSPM). Resultant accelerations were greater for DORLeft than TIBLeft for 60% of the gait cycle (p < 0.001) and greater for DORRight than TIBRight for 50% of the gait cycle (p < 0.003). The larger accelerations at the dorsal foot than the tibia can be explained by movement at the ankle joint, and the placement location relative to the hip. The dorsal foot location can be used to effectively measure accelerations and external mechanical load when it is not feasible to place the accelerometer on the tibia, however results between the two locations should not be compared.


Assuntos
Acelerometria/instrumentação , Monitores de Aptidão Física , Pé/fisiologia , Corrida/fisiologia , Tíbia/fisiologia , Aceleração , Adulto , Articulação do Tornozelo/fisiologia , Fenômenos Biomecânicos , Estudos de Viabilidade , Feminino , Quadril/fisiologia , Humanos , Masculino , Movimento/fisiologia , Percepção/fisiologia , Esforço Físico/fisiologia , Adulto Jovem
6.
J Strength Cond Res ; 33(9): 2338-2343, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31269002

RESUMO

Wills, JA, Saxby, DJ, Glassbrook, DJ, and Doyle, TLA. Load-carriage conditioning elicits task-specific physical and psychophysical improvements in males. J Strength Cond Res 33(9): 2338-2343, 2019-Load carriage is a requirement of many military roles and is commonly used as an assessment of soldier physical readiness. Loaded, compared with unloaded, walking tasks elicit increased physical demands, particularly around the hip joint, which can exceed the initial capacity of military personnel. This study aimed to identify and characterize physical performance responses to a lower-limb focused physical training program targeted toward load-carriage task demands. Fifteen healthy male civilians (22.6 ± 1.5 years, 1.82 ± 0.06 m, and 84.1 ± 6.9 kg) completed a 10-week physical training program consisting of resistance training and weighted walking. A load-carriage task representing the Australian Army All Corps minimum standard (5 km at 5.5 km·h, wearing a 23-kg torso-borne vest) was completed before and on completion of the 10-week training program. Heart rate and rating of perceived exertion measures were collected throughout the load-carriage task. The performance measures of countermovement and squat jumps, push-ups, sit-ups, and beep test were performed before, mid-way, and on completion (weeks 0, 6, and 11) of the 10-week training program. Psychophysical performance, as measured by rating of perceived exertion, significantly decreased (p < 0.05) during the load-carriage task after training, demonstrating improvements in psychophysical responses. The training program resulted in significant increases in squat jump maximal force, push-ups, sit-ups (p < 0.05), and estimated maximal oxygen uptake (p < 0.05). Physical performance improvements and positive physiological adaptations to a load-carriage task were elicited in males after completing a 10-week training program. Military organizations could use this evidence-based training program to efficiently train soldiers to improve their load-carriage capacity.


Assuntos
Militares , Condicionamento Físico Humano/fisiologia , Treinamento de Força , Caminhada/fisiologia , Suporte de Carga/fisiologia , Adaptação Fisiológica , Austrália , Teste de Esforço , Frequência Cardíaca , Humanos , Remoção , Extremidade Inferior/fisiologia , Masculino , Força Muscular , Consumo de Oxigênio , Esforço Físico , Adulto Jovem
7.
Sports Med Open ; 5(1): 24, 2019 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-31187357

RESUMO

BACKGROUND: Rugby league is a collision sport, where players are expected to be physically competent in a range of areas, including aerobic fitness, strength, speed and power. Several studies have attempted to characterise the physical demands of rugby league match-play, but these studies often have relatively small sample sizes based on one or two clubs, which makes generalisation of the findings difficult. Therefore, the aim of this review was to synthesise studies that investigated the physical demands of professional rugby league match-play. METHODS: SPORTDiscus, CINAHL, MEDLINE (EBSCO) and Embase (EBSCO) databases were systematically searched from inception until October 2018. Articles were included if they (1) recruited professional rugby league athletes aged ≥ 18 years and (2) provided at least one match-play relevant variable (including playing time, total and relative distance, repeat high-intensity efforts (RHIE), efforts per RHIE, accelerations and decelerations, total and relative collisions). Meta-analyses were used to provide pooled estimates ± 95% confidence intervals. RESULTS: A total of 30 studies were included. Pooled estimates indicated that, compared to adjustables and backs, forwards have less playing time (- 17.2 ± 5.6 and - 25.6 ± 5.8 min, respectively), cover less 'slow-speed' (- 2230 ± 735 and - 1348 ± 655 m, respectively) and 'high-speed' distance (- 139 ± 108 and - 229 ± 101 m, respectively), but complete more relative RHIEs (+ 0.05 ± 0.05 and + 0.08 ± 0.04 per minute, respectively), and total (+ 12.0 ± 8.1 and + 12.8 ± 7.2 collisions, respectively) and relative collisions (+ 0.32 ± 0.22 and + 0.41 ± 0.22 collisions per minute, respectively). Notably, when the distance was expressed relative to playing time, forwards were not different from adjustables and backs in slow-speed (P ≥ 0.295) and high-speed (P ≥ 0.889) relative distance. The adjustables and backs subgroups were similar in most variables, except playing time (shorter for adjustables, - 8.5 ± 6.2 min), slow-speed distance (greater for adjustables, + 882 ± 763 m) and total relative distance (greater for adjustables, + 11.3 ± 5.2 m·min-1). There were no significant differences between positional groups for efforts per RHIE, accelerations and decelerations (P ≥ 0.745). CONCLUSIONS: These results indicate the unique physical demands of each playing position and should be considered by strength and conditioning and tactical coaches when planning for professional rugby league performance. PROTOCOL REGISTRATION: https://osf.io/83tq2/.

8.
J Sci Med Sport ; 22(2): 158-163, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30595163

RESUMO

OBJECTIVES: To determine the effects of different body armour types, carried loads, and walking speeds on trunk and lower-limb joint biomechanics. DESIGN: Within-subjects repeated measures to determine the effects of different body armour types, carried loads, and walking speeds on trunk and lower-limb joint biomechanics. METHODS: Twenty soldiers (29.5±7.1yrs) completed a treadmill walking protocol in an unloaded (baseline) condition and wearing a control, Tiered Body Armour System (TBAS) and five different armour types (cARM1-2, pARM1) with two load configurations (15 and 30kg) for a total of eight armour×load ensembles. In each ensemble, participants walked for 10min at 1.53ms-1 and 1.81ms-1 speeds. Whole-body marker kinematics and ground reaction forces were used, along with a scaled anatomic model, to determine peak lower-limb joint angles, net joint moments, and negative knee work. Peak parameters were compared between armour types, walking speeds, and carried loads using repeated measures ANOVAs. RESULTS: Peak plantarflexion and hip abduction moments were reduced when wearing cARM1 (p=0.040, p=0.045) and cARM2 (p=0.045, p=0.003) compared to TBAS, while carrying 30kg and/or walking fast. This suggests positive benefits of load distribution at higher task demands. Joint moments increased when participants carried greater load and/or walked faster, and the combined effects of carried load and walking speed were mostly additive. CONCLUSIONS: Primarily hip-borne load carriage does not negatively alter joint kinetics, and some positive adaptations occurred during tasks with higher demands. These results can inform equipment design and physical training programs for load carriage.


Assuntos
Transtornos Traumáticos Cumulativos/etiologia , Extremidade Inferior/lesões , Militares , Suporte de Carga , Adulto , Fenômenos Biomecânicos , Quadril , Humanos , Masculino , Roupa de Proteção , Fatores de Risco , Tronco , Caminhada , Adulto Jovem
9.
J Biomech ; 83: 174-180, 2019 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-30527387

RESUMO

Soldiers regularly transport loads weighing >20 kg at slow speeds for long durations. These tasks elicit high energetic costs through increased positive work generated by knee and ankle muscles, which may increase risk of muscular fatigue and decrease combat readiness. This study aimed to determine how modifying where load is borne changes lower-limb joint mechanical work production, and if load magnitude and/or walking speed also affect work production. Twenty Australian soldiers participated, donning a total of 12 body armor variations: six different body armor systems (one standard-issue, two commercially available [cARM1-2], and three prototypes [pARM1-3]), each worn with two different load magnitudes (15 and 30 kg). For each armor variation, participants completed treadmill walking at two speeds (1.51 and 1.83 m/s). Three-dimensional motion capture and force plate data were acquired and used to estimate joint angles and moments from inverse kinematics and dynamics, respectively. Subsequently, hip, knee, and ankle joint work and power were computed and compared between armor types and walking speeds. Positive joint work over the stance phase significantly increased with walking speed and carried load, accompanied by 2.3-2.6% shifts in total positive work production from the ankle to the hip (p < 0.05). Compared to using cARM1 with 15 kg carried load, carrying 30 kg resulted in significantly greater hip contribution to total lower-limb positive work, while knee and ankle work decreased. Substantial increases in hip joint contributions to total lower-limb positive work that occur with increases in walking speed and load magnitude highlight the importance of hip musculature to load carriage walking.


Assuntos
Articulações/fisiologia , Extremidade Inferior/fisiologia , Velocidade de Caminhada/fisiologia , Adulto , Fenômenos Biomecânicos , Teste de Esforço , Humanos , Masculino , Fadiga Muscular , Suporte de Carga
10.
PLoS One ; 13(11): e0206859, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30395591

RESUMO

Musculoskeletal injuries (MSI) in the military reduce soldier capability and impose substantial costs. Characterizing biomechanical surrogates of MSI during commonly performed military tasks (e.g., load carriage) is necessary for evaluating the effectiveness of possible interventions to reduce MSI risk. This study determined the effects of body-borne load distribution, load magnitude, and walking speed on tibiofemoral contact forces. Twenty-one Australian Army Reserve soldiers completed a treadmill walking protocol in an unloaded condition and wearing four armor types (standard-issue and three prototypes) with two load configurations (15 and 30 kg) for a total of 8 armor x load ensembles. In each ensemble, participants completed a 5-minute warm-up, and then walked for 10 minutes at both moderate (1.53 m⋅s-1) and fast (1.81 m⋅s-1) speeds. During treadmill walking, three-dimensional kinematics, ground reaction forces, and muscle activity from nine lower-limb muscles were collected in the final minute of each speed. These data were used as inputs into a neuromusculoskeletal model, which estimated medial, lateral and total tibiofemoral contact forces. Repeated measures analyses of variance revealed no differences for any variables between armor types, but peak medial compartment contact forces increased when progressing from moderate to fast walking and with increased load (p<0.001). Acute exposure to load carriage increased estimated tibiofemoral contact forces 10.1 and 19.9% with 15 and 30kg of carried load, respectively, compared to unloaded walking. These results suggest that soldiers carrying loads in excess of 15 kg for prolonged periods could be at greater risk of knee MSI than those with less exposure.


Assuntos
Traumatismos do Joelho/fisiopatologia , Músculo Esquelético/fisiopatologia , Velocidade de Caminhada/fisiologia , Caminhada/fisiologia , Adulto , Fenômenos Biomecânicos , Eletromiografia , Humanos , Traumatismos do Joelho/diagnóstico por imagem , Articulação do Joelho/fisiopatologia , Masculino , Militares , Músculo Esquelético/lesões
11.
J Sci Med Sport ; 21(5): 508-512, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28754606

RESUMO

OBJECTIVES: To investigate how knee kinematics, kinetics and loading changes during sidestepping tasks following a prolonged running protocol performed in a laboratory setting. DESIGN: All participants performed sidestepping, and crossover cutting tasks in a randomised order before and after a 60min running protocol on a non-motorised treadmill that simulated an AF game. METHODS: Eight healthy male participants who partook in semi-professional and amateur Australian Football undertook a series of straight line runs, sidestepping (SS), and crossover cutting (XO) tasks before and after a simulated game of Australian football. Kinematic data were analysed at initial foot contact of the SS and XO manoeuvres and kinetic data were analysed during the weight acceptance phase of the stance. RESULTS: The knee was significantly more flexed at foot contact following fatigue compared to pre-fatigue states. Fatigue was also a factor contributing to significant increases in internal knee extension moments. Significant differences were also observed between SS and XO trials with flexion/extension moments, with notable differences in varus/valgus and internal/external rotation moments. CONCLUSIONS: Acute angles of knee flexion at foot strike in a fatigued state may place the joint at an increased risk of injury. Increases in knee extension moments in the fatigued state suggests the knee joint must withstand significantly high stresses once fatigued.


Assuntos
Articulação do Joelho/fisiologia , Movimento/fisiologia , Rotação , Corrida/fisiologia , Suporte de Carga/fisiologia , Adolescente , Adulto , Lesões do Ligamento Cruzado Anterior/etiologia , Austrália , Fenômenos Biomecânicos , Teste de Esforço/métodos , Fadiga/etiologia , Futebol Americano/fisiologia , Humanos , Masculino , Amplitude de Movimento Articular/fisiologia , Fatores de Tempo , Adulto Jovem
12.
Ergonomics ; 61(4): 566-575, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28918698

RESUMO

Soldiers carry heavy loads that may cause general discomfort, shoulder pain and injury. This study assessed if new body armour designs that incorporated a hip belt reduced shoulder pressures and improved comfort. Twenty-one Australian soldiers completed treadmill walking trials wearing six different body armours with two different loads (15 and 30 kg). Contact pressures applied to the shoulders were measured using pressure pads, and qualitative assessment of comfort and usability were acquired from questionnaires administered after walking trials. Walking with hip belt compared to no hip belt armour resulted in decreased mean and maximum shoulder pressures (p < 0.005), and 30% fewer participants experiencing shoulder discomfort (p < 0.005) in best designs, although hip discomfort did increase. Laterally concentrated shoulder pressures were associated with 1.34-times greater likelihood of discomfort (p = 0.026). Results indicate body armour and backpack designs should integrate a hip belt and distribute load closer to shoulder midline to reduce load carriage discomfort and, potentially, injury risk. Practitioner Summary: Soldiers carry heavy loads that increase their risk of discomfort and injury. New body armour designs are thought to ease this burden by transferring the load to the hips. This study demonstrated that designs incorporating a hip belt reduced shoulder pressure and shoulder discomfort compared to the current armour design.


Assuntos
Militares , Equipamento de Proteção Individual/efeitos adversos , Pressão/efeitos adversos , Dor de Ombro/prevenção & controle , Suporte de Carga , Adulto , Austrália , Desenho de Equipamento , Quadril , Humanos , Dor de Ombro/etiologia , Adulto Jovem
13.
Gait Posture ; 54: 318-324, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28411551

RESUMO

Body armor covers anatomical landmarks that would otherwise be used to track trunk and pelvis movement in motion analysis. This study developed and evaluated a new marker set, and compared it to placing markers on the skin and over-top of body armor. In our method, pelvis and trunk motions were measured using a custom-built sacral and upper-back marker cluster, respectively. Joint angles and ranges of motion were determined while participants walked without and with body armor. Angles were obtained from the new marker set and compared against conventional marker sets placed on the skin or over-top the body armor. Bland-Altman analyses compared the agreement of kinematic parameters between marker sets, while joint angle waveforms were compared using inter-protocol coefficient of multiple correlations (CMCs). The intra- and inter-session similarities of joint angle waveforms from each marker set were also assessed using CMCs. There was a strong agreement between joint angles from the new marker set and markers placed directly on the skin at key anatomical landmarks. The agreement worsened with markers placed on top of body armor. Inter-protocol CMCs comparing markers on body armor to the new marker set were poor compared to CMCs between skin-mounted markers and the new marker set. Intra- and inter-session repeatability were higher for the new marker set compared to placing markers over-top of body armor. The new marker set provides a viable alternative for researchers to reliably measure trunk and pelvis motion when equipment, such as body armor, obscures marker placement.


Assuntos
Marcha/fisiologia , Pelve/fisiologia , Caminhada/fisiologia , Adulto , Fenômenos Biomecânicos , Voluntários Saudáveis , Humanos , Masculino , Reprodutibilidade dos Testes
14.
Inj Prev ; 22(2): 123-8, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26399611

RESUMO

BACKGROUND: Exercise-based training programmes are commonly used to prevent sports injuries but programme effectiveness within community men's team sport is largely unknown. OBJECTIVE: To present the intention-to-treat analysis of injury outcomes from a clustered randomised controlled trial in community Australian football. METHODS: Players from 18 male, non-elite, community Australian football clubs across two states were randomly allocated to either a neuromuscular control (NMC) (intervention n=679 players) or standard-practice (control n=885 players) exercise training programme delivered as part of regular team training sessions (2× weekly for 8-week preseason and 18-week regular-season). All game-related injuries and hours of game participation were recorded. Generalised estimating equations, adjusted for clustering (club unit), were used to compute injury incidence rates (IIRs) for all injuries, lower limb injuries (LLIs) and knee injuries sustained during games. The IIRs were compared across groups with cluster-adjusted Injury Rate Ratios (IRRs). RESULTS: Overall, 773 game injuries were recorded. The lower limb was the most frequent body region injured, accounting for 50% of injuries overall, 96 (12%) of which were knee injuries. The NMC players had a reduced LLI rate compared with control players (IRR: 0.78 (95% CI 0.56 to 1.08), p=0.14.) The knee IIR was also reduced for NMC compared with control players (IRR: 0.50 (95% CI 0.24 to 1.05), p=0.07). CONCLUSIONS: These intention-to-treat results indicate that positive outcomes can be achieved from targeted training programmes for reducing knee and LLI injury rates in men's community sport. While not statistically significant, reducing the knee injury rate by 50% and the LLI rate by 22% is still a clinically important outcome. Further injury reductions could be achieved with improved training attendance and participation in the programme.


Assuntos
Traumatismos em Atletas/prevenção & controle , Exercício Físico , Futebol Americano , Traumatismos do Joelho/prevenção & controle , Articulação do Joelho/fisiologia , Adulto , Traumatismos em Atletas/epidemiologia , Austrália/epidemiologia , Fenômenos Biomecânicos , Análise por Conglomerados , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Traumatismos do Joelho/epidemiologia , Masculino , Educação Física e Treinamento/métodos , Avaliação de Programas e Projetos de Saúde
15.
Ergonomics ; 59(6): 813-20, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26526182

RESUMO

Carrying a casualty on a stretcher is a critical task conducted in a range of occupations. To ensure that personnel have the requisite physical capacity to conduct this task, two bilateral jerry can carries were used to predict individual performance in a four-person stretcher carry. Results demonstrated a bilateral 22-kg jerry can carry (R(2) = 0.59) had superior predictive ability of stretcher carry performance than a bilateral 15-kg jerry can carry (R(2) = 0.46). Pre- to post-carry changes in grip endurance (p > 0.05), back-leg isometric strength (p > 0.05) and leg power (p > 0.05) were not significantly different between carry tasks. There was no significant difference in heart rate (p > 0.05) and oxygen consumption (p > 0.05) between the stretcher carry and either jerry can carry. Thus, on the basis of performance correlations and physiological measures, the 22-kg jerry can carry is an appropriate predictive assessment of four-person stretcher carriage. Practitioner Summary: This study investigated the ability of a jerry can carry to predict individual performance on a four-person stretcher carry. Performance correlations were substantiated with physiological measures to demonstrate similar physical requirements between task and test. These results can be used to set physical employment standards to assess stretcher carriage.


Assuntos
Músculos do Dorso , Força da Mão , Frequência Cardíaca , Militares , Força Muscular , Consumo de Oxigênio , Macas (Leitos) , Análise e Desempenho de Tarefas , Adulto , Feminino , Humanos , Contração Isométrica , Perna (Membro) , Remoção , Masculino , Músculo Esquelético , Resistência Física , Adulto Jovem
16.
Br J Sports Med ; 48(8): 718-23, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23482922

RESUMO

OBJECTIVE: To determine the reach and adoption of a coach-led exercise training programme for lower limb injury prevention. DESIGN: Secondary analysis of data from a group-clustered randomised controlled trial. SETTING: A periodised exercise training warm-up programme was delivered to players during training sessions over an 8-week preseason (weeks 1-8) and 18-week playing season. PARTICIPANTS: 1564 community Australian football players. MAIN OUTCOME MEASUREMENTS: Reach, measured weekly, was the number of players who attended training sessions. Adoption was the number of attending players who completed the programme in full, partially or not at all. Reasons for partial or non-participation were recorded. RESULTS: In week 1, 599 players entered the programme; 55% attended 1 training session and 45% attended > 1 session. By week 12, 1540 players were recruited but training attendance (reach) decreased to <50%. When players attended training, the majority adopted the full programme-ranging from 96% (week 1) to above 80% until week 20. The most common reasons for low adoption were players being injured, too sore, being late for training or choosing their own warm-up. CONCLUSIONS: The training programme's reach was highest preseason and halved at the playing season's end. However, when players attended training sessions, their adoption was high and remained close to 70% by season end. For sports injury prevention programmes to be fully effective across a season, attention also needs to be given to (1) encouraging players to attend formal training sessions and (2) considering the possibility of some form of programme delivery outside of formal training.


Assuntos
Terapia por Exercício/métodos , Futebol Americano/lesões , Traumatismos em Atletas/prevenção & controle , Atitude Frente a Saúde , Análise por Conglomerados , Humanos , Prática Profissional , Vitória , Austrália Ocidental
17.
J Strength Cond Res ; 28(3): 767-73, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23897024

RESUMO

Military manual handling requirements range from discrete lifts to continuous and repetitive lifting tasks. For the military to introduce a discrete lifting assessment, the assessment must be predictive of the various submaximum lifting tasks personnel are required to perform. This study investigated the relationship between discrete and repetitive military lifting to assess the validity of implementing a discrete lifting test. Twenty-one soldiers from the Australian Army completed a whole-body box-lifting assessment as a one repetition maximum (1RM) and a series of submaximal lifting repetitions (% 1RM). Performance was measured between the number of lifting repetitions that could be performed at different intensities between 58 and 95% 1RM. A strong curvilinear relationship existed across the entire submaximal lifting range (r = 0.72, p ≤ 0.05). The model developed demonstrated a low predictive error (standard error of the estimate = 7.2% 1RM) with no differences detected in the relationship when comparing individuals of high and low strength. Findings support the use of a discrete functional lifting assessment in providing coverage of a broad range of military lifting tasks. Parallels can be drawn between the trend reported in the current study and weight-training exercises reported in the literature.


Assuntos
Teste de Esforço , Remoção , Militares , Força Muscular/fisiologia , Resistência Física/fisiologia , Análise e Desempenho de Tarefas , Adolescente , Adulto , Austrália , Humanos , Masculino , Músculo Esquelético/fisiologia , Valor Preditivo dos Testes , Levantamento de Peso/fisiologia , Avaliação da Capacidade de Trabalho , Adulto Jovem
18.
Br J Sports Med ; 48(8): 702-7, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24047571

RESUMO

BACKGROUND: Players are the targeted end-users and beneficiaries of exercise-training programmes implemented during coach-led training sessions, and the success of programmes depends upon their active participation. Two variants of an exercise-training programme were incorporated into the regular training schedules of 40 community Australian Football teams, over two seasons. One variant replicated common training practices, while the second was an evidence-based programme to alter biomechanical and neuromuscular factors related to risk of knee injuries. This paper describes the structure of the implemented programmes and compares players' end-of-season views about the programme variants. METHODS: This study was nested within a larger group-clustered randomised controlled trial of the effectiveness of two exercise-training programmes (control and neuromuscular control (NMC)) for preventing knee injuries. A post-season self-report survey, derived from Health Belief Model constructs, included questions to obtain players' views about the benefits and physical challenges of the programme in which they participated. RESULTS: Compared with control players, those who participated in the NMC programme found it to be less physically challenging but more enjoyable and potentially of more benefit. Suggestions from players about potential improvements to the training programme and its future implementation included reducing duration, increasing range of drills/exercises and promoting its injury prevention and other benefits to players. CONCLUSIONS: Players provide valuable feedback about the content and focus of implemented exercise-training programmes, that will directly inform the delivery of similar, or more successful, programmes in the future.


Assuntos
Atitude Frente a Saúde , Terapia por Exercício/psicologia , Futebol Americano/lesões , Extremidade Inferior/lesões , Adolescente , Adulto , Traumatismos em Atletas/prevenção & controle , Traumatismos em Atletas/psicologia , Austrália , Terapia por Exercício/métodos , Humanos , Adulto Jovem
19.
J Strength Cond Res ; 27(10): 2836-41, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23302748

RESUMO

Australian football (AF) is a sport which requires a vast array of physiological qualities, including high levels of strength and power. However, the power characteristics of AF players, particularly at the subelite level have not been extensively studied with further investigation warranted to understand the power capabilities and training requirements of elite and subelite AF groups. Therefore, the aim of this investigation was to develop a lower-body power profile of elite and subelite AF players. Eighteen elite and 12 subelite AF players completed a 1 repetition maximum (1RM) squat test to determine maximal lower-body strength, and countermovement jump (CMJ) and squat jump (SJ) testing to assess lower-body muscular power performance. Maximal lower-body strength was not statistically different between groups (p > 0.05). Elite players produced greater levels of peak power for CMJ at loads of 0, 30 (p < 0.05), and 40% (p < 0.01) of 1RM in comparison to subelite players. Squat jump peak power was statistically different between groups at 0, 20, 30, and 40% (p < 0.01) of 1RM; with elite players producing greater power than their subelite counterparts at all measured loads for SJ. Findings from this investigation demonstrate that elite AF players are able to generate greater levels of lower-body power than subelite AF players, despite no significant differences existing in maximal lower-body strength or body mass. As lower-body power levels clearly differentiate elite and subelite AF players, emphasis may be placed on improving the power levels of subelite players, particularly those aspiring to reach the elite level.


Assuntos
Desempenho Atlético/fisiologia , Extremidade Inferior/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Futebol/fisiologia , Estudos Transversais , Teste de Esforço , Humanos , Masculino , Vitória , Adulto Jovem
20.
Br J Sports Med ; 46(13): 917-22, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22547562

RESUMO

PURPOSE: Determine if balance and technique training (BTT) implemented adjunct to normal Australian football (AF) training reduces external knee loading during sidestepping. Additionally, the authors determined if an athlete's knee joint kinematics and kinetics change over a season of AF. METHODOLOGY: Eight amateur-level AF clubs (n=1,001 males) volunteered to participate in either 28 weeks of BTT or a 'sham' training (ST) adjunct to their normal preseason and regular training. A subset of 34 athletes (BTT, n=20; ST, n=14) were recruited for biomechanical testing in weeks 1-7 and 18-25 of the 28-week training intervention. During biomechanical testing, participants completed a series running, preplanned (PpSS) and unplanned sidestepping (UnSS) tasks. A linear mixed model (α=0.05) was used to determine if knee kinematics and peak moments during PpSS and UnSS were influenced by BTT and/or a season of AF. RESULTS: Both training groups significantly (p=0.025) decreased their peak internal-rotation knee moments during PpSS, and significantly (p=0.022) increased their peak valgus knee moments during UnSS following their respective training interventions. CONCLUSIONS: BTT was not effective in changing an athlete's knee joint biomechanics during sidestepping when conducted in 'real-world' training environments. Following normal AF training, the players had different changes to their knee joint biomechanics during both preplanned and unplanned sidestepping. When performing an unplanned sidestepping task in the latter half of a playing season, athletes are at an increased risk of ACL injury. The authors therefore recommend both sidestepping tasks are performed during biomechanical testing when assessing the effectiveness of prophylactic training protocols.


Assuntos
Futebol Americano/fisiologia , Articulação do Joelho/fisiologia , Análise de Variância , Fenômenos Biomecânicos/fisiologia , Humanos , Masculino , Equilíbrio Postural/fisiologia , Amplitude de Movimento Articular/fisiologia , Rotação , Corrida/fisiologia , Austrália Ocidental , Adulto Jovem
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