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  • Author: Dirkjan H.E.J. Veeger x
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Luc H.V. van der Woude, Dirk-Jan E.J. Veeger and Rients H. Rozendal

A review of wheelchair research within the scope of the wheelchair as a means of daily ambulation is presented. The relevance of a combined biomechanical and physiological research approach is advocated for enhancing the body of knowledge of wheelchair ergonomics, that is, the wheelchair/user interaction in relation to aspects of vehicle mechanics and the user’s physical condition. Results of experiments regarding variations in the wheelchair/user interface stress the possibilities of optimization in terms of wheelchair dimensions and user characteristics. Analysis of propulsion technique is aimed at the within-cycle characteristics and the time-dependent organization of technique.

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Fenna Walhain, Marloes van Gorp, Kenneth S. Lamur, Dirkjan H.E.J. Veeger and Annick Ledebt

Background:

Health-related fitness (HRF) and motor coordination (MC) can be influenced by children’s environment and lifestyle behavior. This study evaluates the association between living environment and HRF, MC, and physical and sedentary activities of children in Suriname.

Methods:

Tests were performed for HRF (morphological, muscular, and cardiorespiratory component), gross MC (Körperkoordinations Test für Kinder), fine MC (Movement Assessment Battery for Children), and self-reported activities in 79 urban and 77 rural 7-year-old Maroon children. Urban-rural differences were calculated by an independent sample t test (Mann-Whitney U test if not normally distributed) and χ2 test.

Results:

No difference was found in body mass index, muscle strength, and the overall score of gross and fine MC. However, urban children scored lower in HRF on the cardiorespiratory component (P ≤ .001), in gross MC on walking backward (P = .014), and jumping sideways (P = 0.011). They scored higher in the gross MC component moving sideways (P ≤ .001) and lower in fine MC on the trail test (P = .036) and reported significantly more sedentary and fewer physical activities than rural children.

Conclusions:

Living environment was associated with certain components of HRF, MC, and physical and sedentary activities of 7-year-old children in Suriname. Further research is needed to evaluate the development of urban children to provide information for possible intervention and prevention strategies.

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Thom T.J. Veeger, Annemarie M.H. de Witte, Monique A.M. Berger, Rienk M.A. van der Slikke, Dirkjan (H.E.J.) Veeger and Marco J.M. Hoozemans

Objective: This study aimed to investigate which characteristics of athlete, wheelchair and athlete-wheelchair interface are the best predictors of wheelchair basketball mobility performance. Design: A total of 60 experienced wheelchair basketball players performed a wheelchair mobility performance test to assess their mobility performance. To determine which variables were the best predictors of mobility performance, forward stepwise linear regression analyses were performed on a set of 33 characteristics, including 10 athlete, 19 wheelchair, and 4 athlete-wheelchair interface characteristics. Results: A total of 8 of the characteristics turned out to be significant predictors of wheelchair basketball mobility performance. Classification, experience, maximal isometric force, wheel axis height, and hand rim diameter—which both are interchangeable with each other and wheel diameter—camber angle, and the vertical distance between shoulder and rear wheel axis—which was interchangeable with seat height—were positively associated with mobility performance. The vertical distance between the front seat and the footrest was negatively associated with mobility performance. Conclusion: With this insight, coaches and biomechanical specialists are provided with statistical findings to determine which characteristics they could focus on best to improve mobility performance. Six out of 8 predictors are modifiable and can be optimized to improve mobility performance. These adjustments could be carried out both in training (maximal isometric force) and in wheelchair configurations (eg, camber angle).

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Annemarie M.H. de Witte, Monique A.M. Berger, Marco J.M. Hoozemans, Dirkjan H.E.J. Veeger and Lucas H.V. van der Woude

The aim of this study was to determine to what extent mobility performance is influenced by offensive or defensive situations and ball possession and to what extent these actions are different for the field positions. From video analysis, the relative duration of the various wheelchair movements during team offense/defense and individual ball possession was compared in 56 elite wheelchair basketball players. A two-way analysis of variance indicated that during offense, the guards and forwards performed longer driving forward than during defense. Overall, centers stood still longer during offense than during defense. Without ball, centers performed driving forward longer than with ball possession. It is concluded that offense, defense, and ball possession influenced mobility performance for the different field positions. These differences can be used to design specific training protocols. Furthermore, field positions require potentially different specific wheelchair configurations to improve performance.

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Rienk M.A. van der Slikke, Daan J.J. Bregman, Monique A.M. Berger, Annemarie M.H. de Witte and Dirk-Jan (H.) E.J. Veeger

Purpose: Classification is a defining factor for competition in wheelchair sports, but it is a delicate and time-consuming process with often questionable validity. New inertial sensor-based measurement methods applied in match play and field tests allow for more precise and objective estimates of the impairment effect on wheelchair-mobility performance. The aim of the present research was to evaluate whether these measures could offer an alternative point of view for classification. Methods: Six standard wheelchair-mobility performance outcomes of different classification groups were measured in match play (n = 29), as well as best possible performance in a field test (n = 47). Results: In match results, a clear relationship between classification and performance level is shown, with increased performance outcomes in each adjacent higher-classification group. Three outcomes differed significantly between the low- and mid-classified groups, and 1, between the mid- and high-classified groups. In best performance (field test), there was a split between the low- and mid-classified groups (5 out of 6 outcomes differed significantly) but hardly any difference between the mid- and high-classified groups. This observed split was confirmed by cluster analysis, revealing the existence of only 2 performance-based clusters. Conclusions: The use of inertial sensor technology to obtain objective measures of wheelchair-mobility performance, combined with a standardized field test, produced alternative views for evidence-based classification. The results of this approach provide arguments for a reduced number of classes in wheelchair basketball. Future use of inertial sensors in match play and field testing could enhance evaluation of classification guidelines, as well as individual athlete performance.

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Tom G. Welter, Maarten F. Bobbert, Bauke M. van Bolhuis, Stan C.A.M. Gielen, Leonard A. Rozendaal and Dirkjan H.E.J. Veeger

We have investigated whether differences in EMG activity in mono- and bi-articuiar muscles for concentric and eccentric contractions (van Bolhuis, Gielen, & van Ingen Schenau, 1998) have to be attributed to a specific muscle coordination strategy or whether they are merely a demonstration of adaptations necessary to adjust for muscle contractile properties. Slow, multi-joint arm movements were studied in a horizontal plane with an external force applied at the wrist. Kinematics and electromyography data from 10 subjects were combined with data from a 3-D model of the arm and a Hill-type muscle model Data for both mono- and bi-articular muscles revealed a higher activation in concentric than in eccentric contractions. The model calculations indicated that the measured difference in activation (20%) was much larger than expected based on the force-velocity relationship (predicting changes of ~5%). Although these findings eliminate the force-velocity relationship as the main explanation for changes in EMG, it cannot be ruled out that other muscle contractile properties, such as history dependence of muscle force, determine muscle activation levels in the task that was studied.