Sensors to measure wrist bending
It sounds like you have not allowed the flex sensor to slide through a sheath attached to the back of the hand.  Consider attaching a sheath to the back of the glove the width of the flex sensor.  It's length should be equal to or greater than the flex sensor when the glove is worn and the hand is fully dorsiflexed.  Anchor only the wired end of the flex sensor to the glove.  If there is still not enough room for the sensor when the hand is fully dorsiflexed, revers the sensor position and anchor the wired end to the back of he hand.  Allow the sensor to travel beyond the cuff of the glove if necessary.