Functional performance tests and return-to-sport decision-making::Focusing on translational research with special interest in fatigue and the brain.

The overall purpose of this dissertation was to contribute to clinical decision-making and functional performance testing across the sport injury spectrum. The three specific objectives encompassed: (1) establishing return to sport criteria following lateral ankle sprains, (2) mapping the reliability characteristics of the reactive balance test, (3) exploring electrophysiological brain changes induced by various types of fatigue when participants performed the Y-balance test and reactive balance test. The systematic review (Chapter 2) showed that currently no scientifically sound return to sport criteria following lateral ankle sprain injury can be determined. This was because not one original research study was performed on this topic. Therefore, we provided an overview of the relevant retrieved questionnaires, clinical assessment measures, functional and sport-specific performance tests within ankle sprain populations. Based upon this empirical research, return to sport variables were proposed. This chapter also encompasses rationales and considerations for return to sport decision-making following lateral ankle sprain injury. In Chapter 3, the reliability study is the first study to assess test-retest, intra- and inter-rater reliability of the reactive balance test within a recreationally trained population. Excellent intra- and inter-rater reliability for both outcomes (i.e. visuomotor response time and accuracy) were found. However, test-retest reliability showed good reliability for visuomotor response time and moderate reliability for accuracy. These results indicate that the reactive balance test is suited for performing analyses over time at the group level. The third study (Chapter 4) was designed to evaluate the impact of mental fatigue on electrophysiological brain measurements during Y-balance test and reactive balance test performance. Even though mental fatigue was successfully induced, it did not affect Y-balance test performance. However, an increase in prefrontal cortex theta activity was observed when performing the Y-balance test in a mentally fatigued state. Which means mental fatigue was successfully induced, and might suggest a lower availability of attentional resources and poorer decision-making. Regarding reactive balance test performance, only accuracy was compromised due to mental fatigue. No changes in visuomotor reaction time and electrophysiological brain outcome measures were found following the mental fatigue intervention. In Chapter 5, the results showed that acute physical fatigue impairs the accuracy of the reactive balance test, while Y-balance test performance and visuomotor response time of the reactive balance test remained unaffected. Nevertheless, the underlying changes at the peripheral and central physiological level completely differed from the previous study. During the execution of both tests, acute physical fatigue induced alterations in electrophysiological brain outcome measures in line with previous Wingate literature. Higher α power in the prefrontal cortex, motor cortex and posterior parietal cortex as well as higher β power in the prefrontal and posterior parietal cortex were observed during the execution of the Y-balance test in a fatigued state. Following acute physical fatigue, α and β power increments were found in the posterior parietal cortex and the prefrontal cortex during the execution of the reactive balance test, respectively. In summary, the research findings of this dissertation show that: (1) no scientifically sound return to sport criteria following lateral ankle sprain injury are currently available; (2) the reactive balance test has acceptable reliability characteristics and therefore is suited for performing analyses over time at the group level. (3) mental and acute physical fatigue do not impact YBT performance, even when underlying physiological and psychological changes are present; (4) the reactive balance test is capable of detecting fatigue changes at the group level culminating in decreased accuracy. When mentally fatigued, no changes at the electrophysiological brain level were measured. In a physically fatigued state the electrophysiological findings were partially in line with previous Wingate literature

An Exploratory Meta-Analytic Review on the Empirical Evidence of Differential Learning as an Enhanced Motor Learning Method

Background: Differential learning (DL) is a motor learning method characterized by high amounts of variability during practice and is claimed to provide the learner with a higher learning rate than other methods. However, some controversy surrounds DL theory, and to date, no overview exists that compares the effects of DL to other motor learning methods. Objective: To evaluate the effectiveness of DL in comparison to other motor learning methods in the acquisition and retention phase. Design: Systematic review and exploratory meta-analysis. Methods: PubMed (MEDLINE), Web of Science, and Google Scholar were searched until February 3, 2020. To be included, (1) studies had to be experiments where the DL group was compared to a control group engaged in a different motor learning method (lack of practice was not eligible), (2) studies had to describe the effects on one or more measures of performance in a skill or movement task, and (3) the study report had to be published as a full paper in a journal or as a book chapter. Results: Twenty-seven studies encompassing 31 experiments were included. Overall heterogeneity for the acquisition phase (post-pre; I-2 = 77%) as well as for the retention phase (retention-pre; I-2 = 79%) was large, and risk of bias was high. The meta-analysis showed an overall small effect size of 0.26 [0.10, 0.42] in the acquisition phase for participants in the DL group compared to other motor learning methods. In the retention phase, an overall medium effect size of 0.61 [0.30, 0.91] was observed for participants in the DL group compared to other motor learning methods. Discussion/Conclusion: Given the large amount of heterogeneity, limited number of studies, low sample sizes, low statistical power, possible publication bias, and high risk of bias in general, inferences about the effectiveness of DL would be premature. Even though DL shows potential to result in greater average improvements between pre- and post/retention test compared to non-variability-based motor learning methods, more high-quality research is needed before issuing such a statement. For robust comparisons on the relative effectiveness of DL to different variability-based motor learning methods, scarce and inconclusive evidence was found

Intramuscular Oxygenation and Muscle Activity of Extensor Carpi Radialis Brevis During Piano Performance: An Observational Study

BACKGROUND: Repetitive piano movements have been associated with playing-related musculoskeletal disorders (PRMDs) such as forearm myalgia and symptoms of lateral epicondylopathy. Despite the high prevalence of PRMDs among pianists, there is poor understanding regarding the underlying physiological mechanisms. Intramuscular oxygenation may play a role in the development of PRMDs. Therefore, this observational study aimed to explore the effect variability of playing piano repertoire on the oxygenation of the extensor carpi radialis brevis (ECRB). METHODS: Surface electromyography (EMG) activity and intramuscular oxygenation data (using near-infrared spectroscopy, NIRS) of the left and right ECRB were recorded in 13 conservatory piano students (8 female, 5 male, mean age 23.54 ± 3.24 years) while playing piano repertoire (virtuoso piece or études) for 20 minutes. From the oxygenation data, relative changes (in the percentage of the baseline measurements at rest) were calculated. RESULTS: For all participants, the oxygenated hemoglobin of the left ECRB over the piano play presented an averaged decline to the baseline resting value, with a sample mean for left ECRB of –7.48% and –11.88% for the right ECRB, ranging from –15.53% to –2.00% and –19.12% to –3.93%, respectively. The deoxygenated hemoglobin ranged in the left ECRB from –5.39% to 39.14% and from –9.37% to 54.01% in the right ECRB. The change in total hemoglobin ranged from –5.35% to 16.80% for the left ECRB and –12.10% to 10.37% for the right ECRB. EMG activity (in % maximal voluntary contraction) presented a mean of 16.85% (range 11.86 to 24.43) for the left ECRB and 23.65% (range 14.46 to 37.91) for the right ECRB. This pilot study presented a Pearson’s r between the averaged oxygenated hemoglobin and EMG of –0.60 for the right ECRB and –0.48 for the left ECRB. CONCLUSION: Piano performance induced an average decline in oxygenated hemoglobin in the left and right ECRB, which differed largely between the specific pieces played. The EMG activity can partially explain these differences. Further research is needed to explore the impact of a ‘dynamic index’ reflecting the piece’s dynamic characteristics and the individual oxygenation characteristics. Med Probl Perform Art 2023;38(4):214–223

Prevalence and incidence of work-related musculoskeletal disorders in secondary industries of 21st century Europe: a systematic review and meta-analysis

Abstract Objective Over the course of the twenty-first century, work-related musculoskeletal disorders are still persisting among blue collar workers. At present, no epidemiological overview exists. Therefore, a systematic review and meta-analysis was performed on the epidemiology of work-related musculoskeletal disorders (WMSD) within Europe’s secondary industries. Methods Five databases were screened, yielding 34 studies for the qualitative analysis and 17 for the quantitative analysis. Twelve subgroups of WMSDs were obtained for the meta-analysis by means of predefined inclusion criteria: back (overall), upper back, lower back, neck, shoulder, neck/shoulder, elbow, wrist/hand, leg (overall), hip, knee, and ankle/feet. Results The most prevalent WMSDs were located at the back (overall), shoulder/neck, neck, shoulder, lower back and wrist WMSDs with mean 12-month prevalence values of 60, 54, 51, 50, 47, and 42%, respectively. The food industry was in the majority of subgroups the most prominent researched sector and was frequently associated with high prevalence values of WMSDs. Incidence ratios of upper limb WMSDs ranged between 0.04 and 0.26. Incidence ratios could not be calculated for other anatomical regions due to the lack of sufficient articles. Conclusion WMSDs are still highly present among blue collar workers. Relatively high prevalence values and low incidence ratios indicate a limited onset of WMSDs with however long-term complaints

Test-retest, intra- and inter-rater reliability of the reactive balance test in patients with chronic ankle instability

IntroductionThe Reactive Balance Test (RBT) could be a valuable addition to research on chronic ankle instability (CAI) and clinical practice, but before it can be used in clinical practice it needs to be reliable. It has already been proven reliable in healthy recreational athletes, but not yet in patients with CAI who have shown persistent deficits in dynamic balance. The study aimed to determine the test-retest, intra-, and inter-rater reliability of the RBT in patients with CAI, and the test-retest and inter-rater reliability of the newly developed RBT score sheet.MethodsWe used a repeated-measures, single-group design to administer the RBT to CAI patients on three occasions, scored by multiple raters. We included 27 participants with CAI. The study used multiple reliability measures, including Pearson r, intra-class correlations (ICC), standard error of measurement (SEM), standard error of prediction (SEP), minimal detectable change (MDC), and Bland–Altman plots, to evaluate the reliability of the RBT’s outcome measures (visuomotor response time and accuracy). It also assessed the test-retest and inter-rater reliability of the RBT score sheet using the same measures.ResultsThe ICC measures for test-retest reliability were similar for accuracy (0.609) and VMRT (0.594). Intra-rater reliability had high correlations and ICCs for accuracy (r = 0.816, ICC = 0.815) and VMRT (r = 0.802, ICC = 0.800). Inter-rater reliability had a higher ICC for VMRT (0.868) than for accuracy (0.690).ConclusionTest-retest reliability was moderate, intra-rater reliability was good, and inter-rater reliability showed moderate reliability for accuracy and good reliability for VMRT. Additionally, the RBT shows robust SEM and mean difference measures. The score sheet method also demonstrated moderate test-retest reliability, while inter-rater reliability was good to excellent. This suggests that the RBT can be a valuable tool in assessing and monitoring balance in patients with CAI

The interaction of acute physical fatigue with three traditional functional performance tests and the reactive balance test

Objectives: To assess the impact of acute physical fatigue on traditional and neurocognitive functional performance tests in recreational athletes. Design: randomized counterbalanced cross-over study, pre-post design Setting: laboratory Participants: Twenty recreational athletes (age = 24 ± 3 years) Main outcome measures: We evaluated fatigue impairments following a 30 s all-out effort in three traditional and one neurocognitive functional performance test. The traditional functional performance tests encompassed the single leg hop for distance (SLH), countermovement jump (CMJ) and Y-balance test (YBT). The neurocognitive functional performance test encompassed the reactive balance test (RBT). A 30 s modified Wingate was used to induce acute physical fatigue. Results: Acute physical fatigue was successfully induced as indicated by a significant increase in heart rate, systolic blood pressure, blood lactate levels and rating of perceived exertion (p < 0.001). Acute physical fatigue induced significant decreases in RBT accuracy (p = 0.004) and SLH performance (p < 0.001). YBT, CMJ and RBT visuomotor reaction time remained unaffected by acute physical fatigue. Conclusions: Acute physical fatigue impairs SLH performance and decreases accuracy in the RBT. YBT and CMJ performance remained unaffected by acute physical fatigue. Clinicians should be aware of this divergent neurocognitive functional impairments caused by one all-out effort to allow well-informed selection of functional performance tests

An exploratory meta-analytic review on the empirical evidence of differential learning as an enhanced motor learning strategy.

Background: Differential learning (DL) is a motor learning method characterized by high amounts of variability during practice and is claimed to provide the learner with a higher learning rate than other methods. However, some controversy surrounds DL theory and to date, no overview exists that compares the effects of DL to other motor learning methods. Objective: To evaluate the effectiveness of DL in comparison to other motor learning methods in both the acquisition and retention phase. Design: Systematic review and exploratory meta-analysis. Methods: PubMed (MEDLINE), Web of Science and Google Scholar were searched until 24 June 2020. To be included, (1) studies had to be experiments where the DL group was compared to a control group engaged in a different motor learning method (lack of practice was not eligible), (2) studies had to describe the effects on one or more measures of performance in a skill or movement task, and (3) the study report had to be published as a full paper in a journal or as a book chapter. Results: Twenty-six studies, encompassing thirty experiments were included. Overall heterogeneity for the acquisition phase (77%) as well as for the retention phase (79%) was large, and general risk of bias was high. The exploratory meta-analysis showed an overall small effect size of 0.26 [0.10, 0.42] in the acquisition phase for participants in the DL group compared to other motor learning methods. In the retention phase, an overall medium effect size of 0.61 [0.30, 0.91] was observed for participants in the DL group compared to other motor learning methods. Discussion/conclusion: Given the large amount of heterogeneity, limited number of studies, low sample sizes, low statistical power, possible publication bias and high risk of bias in general, inferences about the effectiveness of DL would be premature. Even though DL shows potential to be considered as more effective in comparison to non-variability based motor learning methods in both the acquisition and retention phase, more high quality research is needed before issuing such a statement. For a robust comparison of DL to different variability-based motor learning methods, scarce and inconclusive evidence was found on the relative effectiveness of DL