scholarly journals Lumbar- and Cervicothoracic-Spine Loading During a Fast-Bowling Spell

2017 ◽  
Vol 26 (4) ◽  
pp. 257-262 ◽  
Author(s):  
Matt Greig ◽  
Philip Nagy
Keyword(s):  
Outcome Measures ◽  
Repeated Measures ◽  
Ecological Validity ◽  
Lumbar Vertebrae ◽  
Epidemiological Studies ◽  
Injury Incidence ◽  
Total Load ◽  
Governing Body ◽  
Main Effect ◽  
Body Load

Context:Epidemiological studies highlight a prevalence of lumbar vertebrae injuries in cricket fast bowlers, with governing bodies implementing rules to reduce exposure. Analysis typically requires complex and laboratory-based biomechanical analyses, lacking ecological validity. Developments in GPS microtechnologies facilitate on-field measures of mechanical intensity, facilitating screening toward prevention and rehabilitation.Objective:To examine the efficacy of using GPS-mounted triaxial accelerometers to quantify accumulated body load and to investigate the effect of GPS-unit placement in relation to epidemiological observations.Design:Repeated measures, field-based.Setting:Regulation cricket pitch.Participants:10 male injury-free participants recruited from a cricket academy (18.1 ± 0.6 y).Intervention:Each participant was fitted with 2 GPS units placed at the cervicothoracic and lumbar spines to measure triaxial acceleration (100 Hz). Participants were instructed to deliver a 7-over spell of fast bowling, as dictated by governing-body guidelines.Main Outcome Measures:Triaxial total accumulated body and the relative uniaxial contributions were calculated for each over.Results:There was no significant main effect for overs bowled, in either total load or the triaxial contributions to total load. This finding suggests no cumulative fatigue effect across the 10-over spell. However, there was a significant main effect for GPS-unit location, with the lumbar unit exposed to significantly greater load than the cervicothoracic unit in each of the triaxial planes.Conclusions:There was no evidence to suggest that accumulated load significantly increased as a result of spell duration. In this respect the governing-body guidelines for this age group can be considered safe, or potentially even conservative. However, the observation of higher body load at the lumbar spine than at the cervicothoracic spine supports epidemiological observations of injury incidence. GPS microtechnologies might therefore be considered in screening and monitoring of players toward injury prevention and/or during rehabilitation.

Assessment and Training of Visuomotor Reaction Time for Football Injury Prevention

2017 ◽  
Vol 26 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Gary B. Wilkerson ◽  
Kevin A. Simpson ◽  
Ryan A. Clark
Keyword(s):  
Reaction Time ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Injury Risk ◽  
Football Players ◽  
Injury Incidence ◽  
Training Methods ◽  
Characteristic Analysis ◽  
Cut Point ◽  
And Training

Context:Neurocognitive reaction time has been associated with musculoskeletal injury risk, but visuomotor reaction time (VMRT) derived from tests that present greater challenges to visual stimulus detection and motor response execution may have a stronger association.Objective:To assess VMRT as a predictor of injury and the extent to which improvement may result from VMRT training.Design:Cohort study.Setting:University athletic performance center.Participants:76 National Collegiate Athletic Association Division-I FCS football players (19.5 ± 1.4 y, 1.85 ± 0.06 m, 102.98 ± 19.06 kg).Interventions:Preparticipation and postseason assessments. A subset of players who exhibited slowest VMRT in relation to the cohort’s postseason median value participated in a 6-wk training program.Main Outcome Measures:Injury occurrence was related to preparticipation VMRT, which was represented by both number of target hits in 60 s and average elapsed time between hits (ms). Receiver operating characteristic analysis identified the optimum cut point for a binary injury risk classification. A nonparametric repeated-measures analysis of ranks procedure was used to compare posttraining VMRT values for slow players who completed at least half of the training sessions (n = 15) with those for untrained fast players (n = 27).Results:A preparticipation cut point of ≤85 hits (≥705 ms) discriminated injured from noninjured players with odds ratio = 2.30 (90% confidence interval, 1.05–5.06). Slow players who completed the training exhibited significant improvement in visuomotor performance compared with baseline (standardized response mean = 2.53), whereas untrained players exhibited a small performance decrement (group × trial interaction effect, L2 = 28.74; P < .001).Conclusions:Slow VMRT appears to be an important and modifiable injury risk factor for college football players. More research is needed to refine visuomotor reaction-time screening and training methods and to determine the extent to which improved performance values can reduce injury incidence.

Comparing the Effects of Peroneal Muscle Fatigue and Cyclic Loading on Ankle Neuromuscular Control During Lateral-Hop Landing

2015 ◽  
Vol 24 (3) ◽  
pp. 293-299 ◽  
Author(s):  
Kazem Malmir ◽  
Gholam Reza Olyaei ◽  
Saeed Talebian ◽  
Ali Ashraf Jamshidi
Keyword(s):  
Reaction Time ◽  
Muscle Fatigue ◽  
Energy Absorption ◽  
Outcome Measures ◽  
Repeated Measures ◽  
Neuromuscular Control ◽  
Median Frequency ◽  
Peroneus Longus ◽  
Significant Difference ◽  
Main Effect

Context:Cyclic movements and muscle fatigue may result in musculoskeletal injuries by inducing changes in neuromuscular control. Ankle frontal-plane neuromuscular control has rarely been studied in spite of its importance.Objective:To compare the effects of peroneal muscle fatigue and a cyclic passive-inversion (CPI) protocol on ankle neuromuscular control during a lateral hop.Design:Quasi-experimental, repeated measures.Setting:University laboratory.Participants:22 recreationally active, healthy men with no history of ankle sprain or giving way.Interventions:Participants performed a lateral hop before and after 2 interventions on a Biodex dynamometer. They were randomly assigned to intervention order and interventions were 1 wk apart. A passive intervention included 40 CPIs at 5°/s through 80% of maximum range of motion, and a fatigue intervention involved an isometric eversion at 40% of the maximal voluntary isometric contraction until the torque decreased to 50% of its initial value.Main Outcome Measures:Median frequency of the peroneus longus during the fatigue protocol, energy absorption by the viscoelastic tissues during the CPI protocol, and feedforward onset and reaction time of the peroneus longus during landing.Results:A significant fall in median frequency (P < .05) and a significant decrease in energy absorption (P < .05) confirmed fatigue and a change in viscoelastic behavior, respectively. There was a significant main effect of condition on feedforward onset and reaction time (P < .05). No significant main effect of intervention or intervention × condition interaction was noted (P > .05). There was a significant difference between pre- and postintervention measures (P < .0125), but no significant difference was found between postintervention measures (P > .0125).Conclusions:Both fatigue and the CPI may similarly impair ankle neuromuscular control. Thus, in prolonged sports competitions and exercises, the ankle may be injured due to either fatigue or changes in the biomechanical properties of the viscoelastic tissues.

Submaximal Cricket Fast Bowling Offers a Disproportionate Reduction in Loading Versus Performance: An Alternative Workload Intervention

2020 ◽  
Vol 29 (4) ◽  
pp. 483-487
Author(s):  
Matt Greig ◽  
Benjamin Child
Keyword(s):  
Repeated Measures ◽  
Ecological Validity ◽  
Field Evaluation ◽  
Performance Measure ◽  
Ball Speed ◽  
Main Effect ◽  
Global Positioning ◽  
And Performance ◽  
Analysis Of Technique ◽  
Male Cricket

Context: Cricket fast bowlers are particularly susceptible to lumbar spine loading and injury. Quantitative analysis of technique typically involves laboratory-based biomechanical systems with limited ecological validity, whereas contemporary developments in global positioning satellite microtechnologies facilitate an on-field evaluation of loading. Objective: To quantify the influence of submaximal bowling from reduced approach lengths on performance and loading. Design: Repeated-measures, field-based design. Setting: Regulation cricket pitch. Participants: A total of 12 male cricket academy fast bowlers (18.7 [0.7] y), injury free with ≥3 years of competitive experience. Interventions: Each bowler wore 2 global positioning satellite units placed at C7 and L4 to measure triaxial acceleration (100 Hz). Bowlers completed an over (6 deliveries) from a randomized 3-, 6-, 9-, and 12-stride approach. Main Outcome Measures: Ball speed was recorded as the performance measure, with PlayerLoad in the anteroposterior, mediolateral, and vertical planes also calculated for each delivery length. Results: In ball speed, there was a significant main effect for delivery length (P = .02), with a 3-stride approach eliciting significantly less ball speed than a 9-stride (P = .03) or 12-stride (P = .002) approach. In loading, there was a significant main effect for delivery length (P < .001) in the anteroposterior, mediolateral, and vertical planes, with loading increasing linearly as a function of delivery strides. The 6-stride approach elicited a 44% reduction in loading, with a disproportionately small 3.5% decrease in performance. There was a significant main effect for global positioning satellite location (P ≤ .023) in all planes, with L4 eliciting greater loading than C7. Conclusions: A submaximal 6-stride approach yielded the optimum balance between reduced loading and performance inhibition. Reduced delivery length, therefore, offers an alternative to reduced overs in reducing loading in young bowlers and might also have practicable value in the rehabilitation of bowlers postinjury.

scholarly journals Gluteus Medius Muscle Activation During Isometric Muscle Contractions

2011 ◽  
Vol 20 (2) ◽  
pp. 174-186 ◽  
Author(s):  
Catriona O’Dwyer ◽  
David Sainsbury ◽  
Kieran O’Sullivan
Keyword(s):  
Internal Rotation ◽  
Outcome Measures ◽  
Lower Limb ◽  
Repeated Measures ◽  
Muscle Activation ◽  
External Rotation ◽  
Gluteus Medius ◽  
Isometric Contractions ◽  
Main Effect

Context:Functional subdivisions are proposed to exist in the gluteus medius (GM) muscle. Dysfunction of the GM, in particular its functional subdivisions, is commonly implicated in lower limb pathologies. However, there is a lack of empirical evidence examining the role of the subdivisions of the GM.Objectives:To compare the activation of the functional subdivisions of the GM (anterior, middle, and posterior) during isometric hip contractions.Design:Single-session, repeated-measures observational study.Setting:University research laboratory.Participants:Convenience sample of 15 healthy, pain-free subjects.Intervention:Subjects performed 3 maximal voluntary isometric contractions for hip abduction and internal and external rotation on an isokinetic dynamometer with simultaneous recording of surface electromyography (sEMG) activity of the GM subdivisions.Main Outcome Measures:sEMG muscle activity for each functional subdivision of the GM during each hip movement was analyzed using a 1-way repeated-measures ANOVA (post hoc Bonferroni).Results:The response of GM subdivisions during the 3 different isometric contractions was significantly different (interaction effect; P = .003). The anterior GM displayed significantly higher activation across all 3 isometric contractions than the middle and posterior subdivisions (main effect; both P < .001). The middle GM also demonstrated significantly higher activation than the posterior GM across all 3 isometric contractions (main effect; P = .027). There was also significantly higher activation of all 3 subdivisions during both abduction and internal rotation than during external rotation (main effect; both P < .001).Conclusions:The existence of functional subdivisions in the GM appears to be supported by the findings. Muscle activation was not homogeneous throughout the entire muscle. The highest GM activation was found in the anterior GM subdivision and during abduction and internal rotation. Future studies should examine the role of GM functional subdivisions in subjects with lower limb pathologies.

The More, the Merrier? Roles of Device-Student Ratio in Collaborative Inquiries and Its Interactions With External Scripts and Task Complexity

2021 ◽  
pp. 073563312110107
Author(s):  
Cixiao Wang ◽  
Huixiao Le
Keyword(s):  
Conceptual Understanding ◽  
Repeated Measures ◽  
Task Complexity ◽  
Mainland China ◽  
Fifth Grade ◽  
Learning Context ◽  
Simple Task ◽  
Fifth Grade Students ◽  
Main Effect ◽  
The Relationship

In collaborative learning, the intuition “the more device, the merrier” is somehow widely acknowledged, but little research has investigated the relationship between device-student ratio and the learning outcome. This study aims to investigate not only the main effect of different device-student ratio, also to identify the moderators in the learning context including task complexity, external script availability and students’ familiarity to the collaboration settings. A three-round quasi-experiment was conducted in a primary school in mainland China, 130 fifth-grade students from four classes participated. Group worksheet including conceptual understanding and problem-solving tasks were used to collect participants’ inquiry performance. Repeated measures ANOVA was employed in data analysis. Findings indicate that 1:m device-student ratio could be beneficial, and external scripts, and prior collaboration experience could moderate such effect. The different effect of 1:m device-student ratio to 1:1 is only significant in the situation when students are faced with relatively simple task, and the effect size is larger when external script is present. When the task is more complicated, such effect of device-student ratio would only emerge after a period of collaboration. This finding challenged the intuition that one-to-one device-student ratio could be better. Related discussions and recommendations to teaching were made.

scholarly journals Statistical analysis of two arm randomized pre-post designs with one post-treatment measurement

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Fei Wan
Keyword(s):  
Treatment Effect ◽  
Repeated Measures ◽  
Informed Choice ◽  
Clinical Effectiveness ◽  
Change Score ◽  
Post Treatment ◽  
Analysis Of Covariance ◽  
Alternative Methods ◽  
Main Effect ◽  
Comparable Performance

Abstract Background Randomized pre-post designs, with outcomes measured at baseline and after treatment, have been commonly used to compare the clinical effectiveness of two competing treatments. There are vast, but often conflicting, amount of information in current literature about the best analytic methods for pre-post designs. It is challenging for applied researchers to make an informed choice. Methods We discuss six methods commonly used in literature: one way analysis of variance (“ANOVA”), analysis of covariance main effect and interaction models on the post-treatment score (“ANCOVAI” and “ANCOVAII”), ANOVA on the change score between the baseline and post-treatment scores (“ANOVA-Change”), repeated measures (“RM”) and constrained repeated measures (“cRM”) models on the baseline and post-treatment scores as joint outcomes. We review a number of study endpoints in randomized pre-post designs and identify the mean difference in the post-treatment score as the common treatment effect that all six methods target. We delineate the underlying differences and connections between these competing methods in homogeneous and heterogeneous study populations. Results ANCOVA and cRM outperform other alternative methods because their treatment effect estimators have the smallest variances. cRM has comparable performance to ANCOVAI in the homogeneous scenario and to ANCOVAII in the heterogeneous scenario. In spite of that, ANCOVA has several advantages over cRM: i) the baseline score is adjusted as covariate because it is not an outcome by definition; ii) it is very convenient to incorporate other baseline variables and easy to handle complex heteroscedasticity patterns in a linear regression framework. Conclusions ANCOVA is a simple and the most efficient approach for analyzing pre-post randomized designs.

scholarly journals No Self Without Salience: Affective and Self-relevance Ratings of 552 Emotionally Valenced and Neutral Dutch Words

2021 ◽  
Author(s):  
Lora I. Dimitrova ◽  
Eline M. Vissia ◽  
Hanneke Geugies ◽  
Hedwig Hofstetter ◽  
Sima Chalavi ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Emotional Valence ◽  
Age And Gender ◽  
Gender And Age ◽  
Main Effect ◽  
Emotional Salience ◽  
And Gender ◽  
The Relationship

AbstractIt is unknown how self-relevance is dependent on emotional salience. Emotional salience encompasses an individual's degree of attraction or aversion to emotionally-valenced information. The current study investigated the interconnection between self and salience through the evaluation of emotional valence and self-relevance. 56 native Dutch participants completed a questionnaire assessing valence, intensity, and self-relevance of 552 Dutch nouns and verbs. One-way repeated-measures ANCOVA investigated the relationship between valence and self, age and gender. Repeated-measures ANCOVA also tested the relationship between valence and self with intensity ratings and effects of gender and age. Results showed a significant main effect of valence for self-relevant words. Intensity analyses showed a main effect of valence but not of self-relevance. There were no significant effects of gender and age. The most important finding presents that self-relevance is dependent on valence. These findings concerning the relationship between self and salience opens avenues to study an individual's self-definition.

Effects of Calisthenics and Pilates Exercises on Coordination and Proprioception in Adult Women: A Randomized Controlled Trial

2012 ◽  
Vol 21 (3) ◽  
pp. 235-243 ◽  
Author(s):  
Derya Ozer Kaya ◽  
Irem Duzgun ◽  
Gul Baltaci ◽  
Selma Karacan ◽  
Filiz Colakoglu
Keyword(s):  
Outcome Measures ◽  
Repeated Measures ◽  
Controlled Trial ◽  
Exercise Group ◽  
Lower Limbs ◽  
Control Group ◽  
Adult Women ◽  
Kinetic Chain ◽  
Randomized Controlled ◽  
Closed Kinetic Chain

Objective:To assess and compare the effects of 6 mo of Pilates and calisthenics on multijoint coordination and proprioception of the lower limbs at the 3rd and 6th mo of training.Design:Randomized, controlled, assessor-blinded, repeated-measures.Setting:University research laboratory.Participants and Intervention:Healthy, sedentary, female participants age 25–50 y were recruited and randomly divided into 3 groups: a calisthenic exercise group (n = 34, mean age ± SD 40 ± 8 y, body-mass index [BMI] 31.04 ± 4.83 kg/m2), a Pilates exercise group (n = 32, mean age ± SD 37 ± 8 y, BMI 31.04 ± 4.83 kg/m2), and a control group (n = 41, mean age ± SD 41 ± 7 y, BMI 27.09 ± 4.77 kg/m2). The calisthenics and Pilates groups underwent related training programs for 6 mo, while the controls had no specific training.Main Outcome Measures:Coordination and proprioception of the lower extremities with concentric and eccentric performances in the closed kinetic chain assessed with the monitored rehab functional squat system at baseline and at the 3rd and 6th mo of training.Results:For the within-group comparison, coordinative concentric and eccentric deviation values were significantly decreased for both dominant and nondominant lower limbs at pretraining and at the 3rd and 6th mo posttraining in the calisthenics group (P < .05). In contrast, there was no improvement in the Pilates group throughout the training. However, for comparisons between groups, the baseline values of coordinative concentric and eccentric deviations were different in the calisthenics group than in Pilates and the controls (P < .05). There were no differences in the proprioception values of either visible or nonvisible movement in any group throughout the training (P > .05).Conclusions:It seems that calisthenic exercises are more likely to improve coordination of the lower extremity after 3 and 6 mo of training than Pilates exercises. Calisthenic exercises may be useful for individuals who require improved coordination.

scholarly journals Sex Differences, Hormone Fluctuations, Ankle Stability, and Dynamic Postural Control

2012 ◽  
Vol 47 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Hayley Ericksen ◽  
Phillip A. Gribble
Keyword(s):  
Menstrual Cycle ◽  
Postural Control ◽  
Repeated Measures ◽  
Balance Test ◽  
Healthy Women ◽  
Ankle Stability ◽  
Ankle Arthrometer ◽  
Main Effect ◽  
Star Excursion Balance Test ◽  
Anterior Posterior

Context: Hormonal fluctuation as a risk factor in anterior cruciate ligament injury has been investigated with conflicting results. However, the influence of hormone fluctuations on ankle laxity and function has not been thoroughly examined. Objective: To examine the potential hormone contributions to ankle laxity and dynamic postural control during the preovulatory and postovulatory phases of the menstrual cycle using an ankle arthrometer and the Star Excursion Balance Test in healthy women. The cohort group consisted of male control participants. Design: Cohort study. Setting: Research laboratory. Patients or Other Participants: Twenty healthy women (age = 23.8 ± 6.50 years, height = 163.88 ± 8.28 cm, mass = 63.08 ± 12.38 kg) and 20 healthy men (age = 23.90 ± 4.15 years, height = 177.07 ± 7.60 cm, mass = 80.57 ± 12.20 kg). Intervention(s): Ankle stability was assessed with anterior-posterior and inversion-eversion loading. Dynamic postural control was assessed with the posteromedial reaching distance of the Star Excursion Balance Test. Main Outcome Measure(s): Female participants used ovulation kits for 3 months to determine the time of ovulation; during their preovulatory and postovulatory phases, they were tested in the laboratory with an ankle arthrometer and the Star Excursion Balance Test. Male participants were tested on similar dates as controls. For each dependent variable, a time by side by sex repeated-measures analysis of variance was performed. Statistical significance was set a priori at P &lt; .05. Results: For anterior-posterior laxity, a side main effect was noted (F1,38 = 10.93, P = .002). For inversion-eversion laxity, a sex main effect was seen (F1,38 = 10.75, P = .002). For the posteromedial reaching task, a sex main effect was demonstrated (F1,38 = 8.72, P = .005). No influences of time on the dependent variables were evident. Conclusions: Although women presented with more ankle inversion-eversion laxity and less dynamic postural control, hormonal fluctuations during the menstrual cycle (preovulatory compared with postovulatory) did not affect ankle laxity or dynamic postural control, 2 factors that are associated with ankle instability.

Reliability and Stability of Various Hearing-Aid Outcome Measures in a Group of Elderly Hearing-Aid Wearers

1996 ◽  
Vol 39 (5) ◽  
pp. 923-935 ◽  
Author(s):  
Larry E. Humes ◽  
Dan Halling ◽  
Maureen Coughlin
Keyword(s):  
Outcome Measures ◽  
Hearing Aids ◽  
Repeated Measures ◽  
Nonsense Syllable ◽  
Hearing Aid ◽  
Objective Measure ◽  
The Elderly ◽  
Elderly Persons ◽  
Hearing Aid Use ◽  
Hearing Handicap

Twenty elderly persons with hearing impairment were fit with binaural in-the-ear hearing aids and followed for a 6-month period post-fit. Several hearing-aid outcome measures were obtained at 0, 7, 15, 30, 60, 90, and 180 days post-fit. Outcome measures included (a) objective measures of benefit obtained with nonsense-syllable materials in quiet (CUNY Nonsense Syllable Test, NST) and sentences in multitalker babble (Hearing in Noise Test, HINT); (b) two subjective measures of benefit, one derived from pre-fit/post-fit comparisons on a general scale of hearing handicap (Hearing Handicap Inventory for the Elderly, HHIE) and the other based on a subjective scale of post-fit hearing-aid benefit (Hearing Aid Performance Inventory, HAPI); (c) a questionnaire on hearing-aid satisfaction; (d) an objective measure of hearing-aid use; and (e) a subjective measure of hearing-aid use. Reliability and stability of each measure were examined through repeated-measures analyses of variance, a series of test-retest correlations, and, where possible, scatterplots of the scores against their corresponding 95% critical differences. Many of the measures were found to be both reliable and stable indicators of hearing-aid outcome.

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