Upper limb exercise effect on tilt tolerance during orthostatic training of patients with spinal cord injury

Twelve male patients with traumatic spinal cord injury were randomly divided into a group of six experimental and six control subjects. All subjects were tilted from 0 degree to 70 degrees by 10 degrees increments at five-minute intervals until blood pressure dropped below 70/40, hypotensive symptoms appeared, or 70 degrees of tilt was achieved. The experimental subjects performed 60 active bilateral full-range forearm flexion and extension movements per minute during the first and third minute of each tilt angle. The control patients did not perform upper limb exercises during the same orthostatic training procedure. Blood pressure and pulse rate of all subjects were recorded prior to orthostatic training, during the training at specified intervals and posttraining on each day of testing and training. Total group response was quantitated by indicating the tilting protocol step at which subjects experienced orthostatic hypotension requiring termination of the test. All subjects significantly increased their tolerance of higher tilt angles by using this protocol, but there was no significant difference between the exercise group and nonexercise group with reference to tolerance to progressive vertical tilt (Mann-Whitney U test).