Effects of Rugby Wheel Chair design on output

velocity and acceleration

Presented by:

A.M.Sheikh LdSM, UFRGS, 14/11/2012

ahmad.elsheikh@hotmail.com

What is the Rugby wheel chair? Vídeo

Design Considerations

• Ultra-light as well as extremely strong and durable

• “The chair is built to the person.” everything is customised

• The chair: from Al tubing and thickness varies with the weight of the user (in marathon)

• The chair: baked slowly at a low T after weld.

• Aiming to withstand heavy impacts and be easily maneuverable.

The wheels are covered by spoke protectors to prevent

damage during collisions, and all chairs include an anti-

tip device at the back.

Wings are positioned in front of the main wheels to

make the wheelchair more difficult to stop and hold

A bumper designed to help strike and hold opponents is

attached to the front of the chairs.

Objetivo

To quantify the effect of vertical and horizontal seat positions, and wheelchair camber angle on the wheelchair output velocity and acceleration moving on static ergometer.

Methods • Wheelchair frame: [seat height rear (SH),

camber angle (CA) & balance point (BP)]

• Experimental design: 5 trials of the 14m sprint test were performed for each chair dimension.

Methods: Cont´

• Test procedures:

(Torque Tr measured, the acceleration on the court, random order experiments, and ‘14 m sprint test on court’ for 6 s)

Acceleration mean (ax) during pushing phase

Mean velocity (v) during pushing phase

Cycles 2 and 3 of one of the 5 sprint trials for BP+30

Acc. data Velocity data

Conclusions

• The different recorded Ns shows according to configuration.

• Higher velocity was acheived with SH; B+30, and horizontal position of BP+30.

• The acceleration values for PB-30 lower than B

• CA has no significant effect according to Velocity and CA-/+2 for acceleration.

• For this athelete, recommended lower CA, higher SH and forward horizontal position.

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