Sonja De Groot

Dr. Sonja De Groot

orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
10 April 2012 in Journal of Sports Sciences
Verified
Journal Article
Closed access
SGSonja De Groot
Sonja De Groot
IBInge J.M. Balvers
Inge J.M. Balvers
SKSanne M. Kouwenhoven
Sanne M. Kouwenhoven
TJThomas W.J. Janssen
Thomas W.J. Janssen
The purpose of this study was to investigate the reliability and validity of wheelchair basketball field tests. Nineteen wheelchair basketball players performed 10 test items twice to determine the reliability. The validity of the tests was assessed by relating the scores to the players' classification and competition standard, and rating of coach and player. Six field tests' test-retest showed good reliability (Intraclass correlation coefficient (ICC) = 0.80–0.97), while the pass-for-accuracy, free throws, lay-up and spot shot showed weak to moderate reliability (ICC = 0.26–0.67). Most tests showed moderate to good validity (r > 0.60). The results suggest that wheelchair basketball field tests are reliable and valid with the exception of the shooting and passing items, which should be interpreted carefully.

1 May 2013 in Medical Engineering & Physics
Verified
Journal Article
Closed access
SGSonja De Groot
Sonja De Groot
Riemer JK VegterRiemer JK Vegter
Riemer JK Vegter
LWLucas H.V. van der Woude
Lucas H.V. van der Woude
The purpose of this study was to evaluate the effect of wheelchair mass, solid vs. pneumatic tires and tire pressure on physical strain and wheelchair propulsion technique. 11 Able-bodied participants performed 14 submaximal exercise blocks on a treadmill with a fixed speed (1.11 m/s) within 3 weeks to determine the effect of tire pressure (100%, 75%, 50%, 25% of the recommended value), wheelchair mass (0 kg, 5 kg, or 10 kg extra) and tire type (pneumatic vs. solid). All test conditions (except pneumatic vs. solid) were performed with and without instrumented measurement wheels. Outcome measures were power output (PO), physical strain (heart rate (HR), oxygen uptake (VO2), gross mechanical efficiency (ME)) and propulsion technique (timing, force application). At 25% tire pressure PO and subsequently VO2 were higher compared to 100% tire pressure. Furthermore, a higher tire pressure led to a longer cycle time and contact angle and subsequently lower push frequency. Extra mass did not lead to an increase in PO, physical strain or propulsion technique. Solid tires led to a higher PO and physical strain. The solid tire effect was amplified by increased mass (tire × mass interaction). In contrast to extra mass, tire pressure and tire type have an effect on PO, physical strain or propulsion technique of steady-state wheelchair propulsion. As expected, it is important to optimize tire pressure and tire type.

6 June 2019 in PLOS ONE
Verified
Journal Article
Open access
PDF file
TRThomas Rietveld
Thomas Rietveld
Riemer JK VegterRiemer JK Vegter
Riemer JK Vegter
Rienk van der SlikkeRienk van der Slikke
Rienk van der Slikke
AHAldo E. Hoekstra
Aldo E. Hoekstra
LWLucas H. V. van der Woude
Lucas H. V. van der Woude
SGSonja De Groot
Sonja De Groot
The purpose of the current study was to assess the inter-trial reliability and construct validity (talented juniors vs. international adult players) of four wheelchair tennis field tests using inertial measurement units (IMUs). Twenty-one elite wheelchair tennis players completed four tests, which evaluate the sprinting and manoeuvrability abilities in wheelchair tennis. During all tests 3 IMUs were attached to both wheels and the frame of the athlete’s wheelchair. The IMUs enabled analysis of individual test dynamic characteristics, i.e. the linear/rotational velocity and acceleration data, as well as detected pushes. All tests showed high ICCs (0.95–0.99) for the inter-trial reliability for the IMU-based end times and also the construct validity was good, i.e. talented juniors could be discriminated from international adults. Also, velocities and accelerations during the tests could be consistently visualized, meaning that differences in test performance among participants could be designated. Within the experimental context, the field tests could be regarded as reliable and valid. With the use of IMUs it is possible to verify more detailed performance characteristics, visualize the test execution, as well as differentiate between a talented junior and international adult group and within individuals over time.

1 January 2013 in Journal of NeuroEngineering and Rehabilitation
Verified
Journal Article
Open access
PDF file
Riemer JK VegterRiemer JK Vegter
Riemer JK Vegter
Claudine LamothClaudine Lamoth
Claudine Lamoth
SGSonja De Groot
Sonja De Groot
H.E.J. (DirkJan) VeegerH.E.J. (DirkJan) Veeger
H.E.J. (DirkJan) Veeger
LWLucas Hv van der Woude
Lucas Hv van der Woude
Handrim wheelchair propulsion is a complex bimanual motor task. The bimanually applied forces on the rims determine the speed and direction of locomotion. Measurements of forces and torques on the handrim are important to study status and change of propulsion technique (and consequently mechanical strain) due to processes of learning, training or the wheelchair configuration. The purpose of this study was to compare the simultaneous outcomes of two different measurement-wheels attached to the different sides of the wheelchair, to determine measurement consistency within and between these wheels given the expected inter- and intra-limb variability as a consequence of motor control.

16 May 2013 in Medical Engineering & Physics
Verified
Journal Article
Closed access
SGSonja De Groot
Sonja De Groot
MNMieke G. Nieuwenhuizen
Mieke G. Nieuwenhuizen
The purpose of this study was to evaluate the validity and reliability of assessing activities, movement intensity (MI) and energy expenditure (EE) measured by accelerometry. 28 Able-bodied participants performed standardized tasks while an accelerometer was worn and oxygen uptake was measured. After uploading the accelerometer data to the manufacturer's website, a report was received that gave minute-by-minute MI and EE of the performed activities. Validity was assessed by comparing reported activities and EE with the actual performed activities and calculated EE from the oxygen uptake, and by testing whether MI differed between walking velocities and cycling resistances. Reliability was assessed by performing the protocol twice. Except for standing (classified predominantly (82%) as sitting), most activities were categorized mainly correctly (93-100%). A difference in MI was detected between walking speeds but not between cycling resistances. EE was overestimated for walking (ICC=0.54) and underestimated for cycling (ICC=0.03). Reliability of MI was high (ICC=0.91) but reliability for the relative time spent in activities or the step count was weak to moderate. In conclusion, most activities were categorized correctly, MI seemed to be valid and reliable but reliability is low for relative time spent in activities and EE cannot be estimated well.

27 January 2015 in Spinal Cord
Verified
Journal Article
Open access
PDF file
ALAllrisc
Allrisc
ABA J T Bakkum
A J T Bakkum
SGSonja De Groot
Sonja De Groot
JSJ M Stolwijk-Swüste
J M Stolwijk-Swüste
DKD J van Kuppevelt
D J van Kuppevelt
TJT W J Janssen
T W J Janssen
Study design: This is an open randomized controlled trial. Objective: The objective of this study was to investigate the effects of a 16-week hybrid cycle versus handcycle exercise program on fitness and physical activity in inactive people with long-term spinal cord injury (SCI). Setting: The study was conducted in two rehabilitation centers with a specialized SCI unit. Methods: Twenty individuals (SCI⩾8 years) were randomly assigned to a hybrid cycle (voluntary arm exercise combined with functional electrical stimulation (FES)-induced leg exercise) or a handcycle group. During 16 weeks, both groups trained twice a week for 30 min at 65–75% heart rate reserve. Outcome measures obtained before, during and after the program were fitness (peak power output, peak oxygen consumption), submaximal VO2 and heart rate (HR), resting HR, wheelchair skill performance time score) and physical activity (distance travelled in wheelchair and Physical Activity Scale for Individuals with Physical Disabilities (PASIPD) score). Changes were examined using a two-factor mixed-measures analysis of variance. Results: For all fitness parameters, except for submaximal VO2, no interaction effects were found. The hybrid cycle group showed a decrease in VO2 over time in contrast to the handcycle group (P=0.045). An overall reduction in HRrest (5±2 b.p.m.; P=0.03) and overall increase in PASIPD score (6.5±2.1; P=0.002) were found after 16 weeks of training. No overall training effects were found for the other fitness and activity outcome measures. Conclusion: In the current study, hybrid cycling and handcycling showed similar effects on fitness and physical activity, indicating that there seem to be no additional benefits of the FES-induced leg exercise over handcycle training alone.