Background: In wheelchair basketball, trunk function is the key-indicator for classification. A higher trunk strength is related to higher propulsive force. Trunk strength and trunk
flexion seems to impact performance in wheelchair basketball but limited evidence was found in the literature about the impact of trunk impairment on wheelchair activities. Therefore, the aim of this
study is to describe the relationship between trunk flexion and 12 meter wheelchair sprint performance.
Methods: The relationship between trunk flexion and 12m sprint was investigated by measurement of 44 elite level wheelchair basketball players. Classifications were grouped;
classification 1 and 1.5 were group 1 (n=8), 2 and 2.5 were group 2 (n=8), 3 and 3.5 were 3 (n=10) and 4 and 4.5 were group 4 (n=18). Players performed a 12 meter sprint in their own sports wheelchair
ending in a full stop. The 12 meter sprint contained both acceleration and braking. All measurements were performed on the same synthetic soft-top basketball court. Sprint time and trunk flexion was
recorded based on video-analysis. Sprint time commenced when the wheelchair started to move and stopped when the wheelchair was stationary at 12 meter. Trunk flexion was analyzed for the first five
pushes from standstill and was defined as the difference in degrees between the trunk at the beginning and the end of a push.
Results: A one-way ANOVA showed the mean sprint time (s) for group 1 (5.11±0.53 s), group 2 (4.89±0.29 s), group 3 (4.72±0.38 s) and group 4 (4.72±0.34 s) but these small differences
were not significant (p=0.103). However, trunk flexion during the first pushes was significantly different for the different classification groups (p=0.03). Group 1 moved their trunk somewhat backward
(-7.25±19.70 degrees) during the first push while group 2 (8.50±8.45 degrees), group 3 (6.30±11.67 degrees) and group 4 (15.61±12.87 degrees) flexed their trunk. The trunk flexion in the subsequent
pushes was rather uniform for both pushes and classification groups.
Conclusion: The results of this study showed a difference in trunk flexion for the first push between the groups while there is no significant difference in the 12 meter sprint times.
There was no difference in performance between athletes with partial trunk function and athletes with full trunk function. Based on these data, it can be concluded that trunk flexion does not
influence sprint time. Further research is required to investigate the impact of trunk function on other performance variables and to investigate the impact on the current wheelchair basketball