BACKGROUND: Instability of the knee joint during gait is frequently reported by patients with knee osteoarthritis or an anterior cruciate ligament rupture. The assessment of instability in clinical practice and clinical research studies mainly relies on self-reporting. Alternatively, parameters measured with gait analysis have been explored as suitable objective indicators of dynamic knee (in)stability.RESEARCH QUESTION: This literature review aimed to establish an inventory of objective parameters of knee stability during gait.METHODS: Five electronic databases (Pubmed, Embase, Cochrane, Cinahl and SPORTDiscuss) were systematically searched, with keywords concerning knee, stability and gait. Eligible studies used an objective parameter(s) to assess knee (in)stability during gait, being stated in the introduction or methods section. Out of 10717 studies, 89 studies were considered eligible.RESULTS: Fourteen different patient populations were investigated with kinematic, kinetic and/or electromyography measurements during (challenged) gait. Thirty-three possible objective parameters were identified for knee stability, of which the majority was based on kinematic (14 parameters) or electromyography (12 parameters) measurements. Thirty-nine studies used challenged gait (i.e. external perturbations, downhill walking) to provoke knee joint instability. Limited or conflicting results were reported on the validity of the 33 parameters.SIGNIFICANCE: In conclusion, a large number of different candidates for an objective knee stability gait parameter were found in literature, all without compelling evidence. A clear conceptual definition for dynamic knee joint stability is lacking, for which we suggest : "The capacity to respond to a challenge during gait within the natural boundaries of the knee". Furthermore biomechanical gait laboratory protocols should be harmonized, to enable future developments on clinically relevant measure(s) of knee stability during gait.
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Background/Aims: Analogy learning, a motor learning strategy that uses biomechanical metaphors to chunk together explicit rules of a to-be-learned motor skill. This proof-of-concept study aims to establish the feasibility and potential benefits of analogy learning in enhancing stride length regulation in people with Parkinson’s. Methods: Walking performance of thirteen individuals with Parkinson’s was analysed using a Codamotion analysis system. An analogy instruction; “following footprints in the sand” was practiced over 8 walking trials. Single- and dual- (motor and cognitive) task conditions were measured before training, immediately after training and 4-weeks post training. Finally, an evaluation form was completed to examine the interventions feasibility. Findings: Data from 12 individuals (6 females and 6 males, mean age 70, Hoehn and Yahr I-III) were analysed, one person withdrew due to back problems. In the single task condition, statistically and clinically relevant improvements were obtained. A positive trend towards reducing dual task costs after the intervention was demonstrated, supporting the relatively implicit nature of the analogy. Participants reported that the analogy was simple to use and became easier over time. Conclusions: Analogy learning is a feasible and potentially implicit (i.e. reduced working memory demands) intervention to facilitate walking performance in people with Parkinson’s.
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PURPOSE: Athletes require feedback in order to comply with prescribed training programs designed to optimize their performance. In rowing, current feedback parameters on intensity are inaccurate. Mechanical power output is a suitable objective measure for training intensity, but due to movement restrictions related to crew rowing, it is uncertain whether crew rowers are able to adjust their intensity based on power-output feedback. The authors examined whether rowers improve compliance with prescribed power-output targets when visual real-time feedback on power output is provided in addition to commonly used feedback.METHODS: A total of 16 crew rowers rowed in 3 training sessions. During the first 2 sessions, they received commonly used feedback, followed by a session with additional power-output feedback. Targets were set by their coaches before the experiment. Compliance was operationalized as accuracy (absolute difference between target and delivered power output) and consistency (high- and low-frequency variations in delivered power output).RESULTS: Multilevel analyses indicated that accuracy and low-frequency variations improved by, respectively, 65% (P > .001) and 32% (P = .024) when additional feedback was provided.CONCLUSION: Compliance with power-output targets improved when crew rowers received additional feedback on power output. Two additional observations were made during the study that highlighted the relevance of power-output feedback for practice: There was a marked discrepancy between the prescribed targets and the actually delivered power output by the rowers, and coaches had difficulties perceiving improvements in rowers' compliance with power-output targets.
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Force transmission across the wrist during a grasping maneuver of the hand was simulated for three children with juvenile idiopathic arthritis (JIA) and for one healthy age-matched child. Joint reaction forces were estimated using a series of springs between articulating bones. This method (i.e., rigid body spring modeling) has proven useful for examining loading profiles for normally aligned wrists. A novel method (i.e., sliding rigid body spring modeling) designed specifically for studying joint reaction forces of the malaligned JIA wrist is presented in this paper. Loading profiles across the wrist for the unimpaired child were similar using both spring modeling methods. However, the traditional fixed-end method failed to converge to a solution for one of the JIA subjects indicating the sliding model may be more suitable for investigating loading profiles of the malaligned wrist. The results of this study suggest that a larger proportion of force is transferred through the ulno-carpal joint of the JIA wrist than for healthy subjects, with a less than normal proportion of force transferred through the radio-carpal joint. In addition, the ulnar directed forces along the shear axis defined in this study were greater for all three JIA children compared to values for the healthy child. These observations are what were hypothesized for an individual with JIA of the wrist.
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OBJECTIVE: Change in psychophysical capacity, calculated as the ratio between physical capacity and perceived effort, may be a determinant of change in perceived disability. The aim of this study was to identify determinants for change in perceived disability, as measured with the Roland Morris Disability Questionnaire (RMDQ), in patients with non-specific chronic low back pain after rehabilitation.METHODS: Data were gathered for 84 outpatients. Psychophysical capacity (psychophysical static leg lift, psychophysical static trunk lift, and psychophysical dynamic lifting capacity), physical lifting capacity, perceived lifting effort, aerobic capacity and RMDQ were assessed. Associations between change in RMDQ and potential determinants were calculated. Variables associated with change in RMDQ were entered in a multivariate linear regression analysis (backward).RESULTS: Change in psychophysical static trunk lift (r = -0.51), psychophysical dynamic lifting capacity (r = -0.53) and psycho-physical static leg lift capacity (r = -0.23) were significantly associated with change in RMDQ. The RMDQ score at baseline (beta = -0.438), change in psychophysical dynamic lifting capacity (beta = -0.109), psychophysical static trunk lift capacity (beta = -0.038), psychophysical static leg lift capacity (beta = -0.012) and static leg lift capacity (beta = 0.007) all contributed significantly to the regression model (r2 = 52%).CONCLUSION: Improvements in psychophysical lifting capacity are determinants for a reduction in perceived disability.
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De natuurwetenschappelijke en technische vakken bedienen zich van hun eigen vaktaal, hetgeen uitdagingen voor leerlingen met zich meebrengt. Deze studie laat zien hoe vakdocenten daarop kunnen worden voorbereid in de lerarenopleiding. De gevolgde onderzoeksmethode is ‘ontwerpgericht onderzoek’, waarbij gedurende drie jaar een curriculair ontwerp werd geconstrueerd, beproefd en verfijnd. Acht lerarenopleiders scheikunde, natuurkunde en techniek en 23 studenten participeerden in het onderzoek. De opbrengsten werden geformuleerd in termen van een concreet ontwerp en als ontwerpprincipes. Deze ontwerpprincipes zijn gestoeld op empirische werk en verankerd in theorieën over het opleiden van leraren, didactiek van natuurwetenschappen en techniek en toegepaste taalwetenschappen. Voor de inhoud van het opleidingsontwerp werd een variant van taalgericht vakonderwijs (TVO) beschreven die is verrijkt met genredidactiek, met als leerobject het practicumverslag. De interventies zijn verdeeld over A) vakcursussen waarin lerarenopleiders de taalgerichte benadering modelleerden, B) cursussen vakdidactiek waarin dezelfde taalgerichte benadering werd bestudeerd, en C) een stageopdracht om te oefenen met deze aanpak in de eigen onderwijspraktijk. Het onderzoek laat zien dat TVO als vorm van vakdidactiek kan worden aangeleerd in een bèta-technische lerarenopleiding en dat daarbij specificering nodig is van de vaktaal en functionele taaltaken. Ook is ruime aandacht nodig voor de uiteenlopende onderwijscontexten waarbinnen studenten werken.
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