Evaluation of Elbow Stretch Reflex Using a Portable Hand-driven Isokinetic System in Normal Adults

OBJECTIVE: To evaluate normal healthy persons without spasticity to observe normal findings of the elbow stretch reflex using a newly developed, portable, hand-driven spasticity-measuring system. METHOD: Thirty normal persons without any disease involving the central or peripheral nervous system were enrolled in this study. The portable hand-driven isokinetic system is able to measure the joint angle, angular velocity, electromyographic (EMG) signals, and torque during elbow passive extension-flexion. One set of 10 passive elbow extension and flexion movements was performed for data acquisition at each angular velocity, including 60, 90, 120, 150 and 180 degrees per second (degrees/sec). Electromyographic data were collected from the biceps brachii and the triceps brachii. Torque data were collected from sensors around the wrist. RESULTS: We were able to detect EMG activity and torque in all subjects by using the new portable hand-driven isokinetic system. EMG activity and torque increased with incremental increase of angular velocities. The joint angle of maximal EMG activity according to different angular velocities did not show any significant difference (116degrees-127degrees in elbow extension and 37degrees-66degrees in elbow flexion). The joint angles of maximal torque according to different angular velocities were not significantly different either. CONCLUSION: Using the portable hand-driven isokinetic system on the elbows of normal subjects, we were able to obtain expected results. By considering our normal findings of the elbow stretch reflex using this system, we propose that the various aspects of spasticity-related data can be measured successfully.

Availability of a Newly Devised Ambulatory Urodynamic System in Spinal Cord Injury

OBJECTIVE: To introduce and evaluate the availability of a newly devised ambulatory urodynamic system using the abdominal EMG (electromyography) method instead of the rectal catheter in measuring the abdominal pressure, and to compare with conventional urodynamic system in patients with spinal cord injury. METHOD: We examined 15 hospitalized subjects with spinal cord injury. Patients were investigated by conventional urodynamics in an examination room, and followed by ambulatory urodynamics in a ward. We used the abdominal EMG and the rectal catheter for the abdominal pressure in the study. We measured urodynamic parameters : volumes of sensations in bladder filling, peak P(det)(detrusor pressure) during filling, maximal P(det) during voiding, bladder capacity, compliance and duration of filling. RESULTS: There was no significant statistic difference in the parameters between the conventional and the ambulatory urodynamics. There were strong correlations between the parameters measured by the rectal catheter and the abdominal EMG in the ambulatory system and between the parameters in the conventional system and in the ambulatory system. CONCLUSION: There were strong correlation and no significant statistic differences in the parameters between the ambulatory system using abdominal EMG method and the conventional system. Therefore, we suggest that the newly devised ambulatory urodynamic system using abdominal EMG method can be used instead of the conventional non-ambulatory system and the conventional ambulatory system.

Errors of Rectal Pressure Measurement in Urodynamic Study of Spinal Cord Injured Patients

OBJECTIVE: The intrarectal pressure can make error during urodynamic study and can decrease the accuracy of detrusor pressures. The purpose of this study was to investigate the incidence and cause of the error in measurement of recral pressure. METHOD: Forty-eight patients with spinal cord injury were enrolled. With the patients in the lithotomy position, catheter was placed into the bladder and the rectum, then urodynamic testing began by infusion of normal saline (20~30degrees C) via urethral catheter. The errors by measurement of rectal pressure during urodynamic study were recorded. According to the position of patients and spasticity of hip flexors, difference of rectal pressure was investigated. RESULTS: The error rate of intrarectal pressure during urodynamic study was 41%. Intrarectal pressure was higher in lithotomy position than in lateral lying position. According to modified Ashworth scale of hip flexors, intrarectal pressure in grade 0 was significantly lower than grade 1, 1.5 and 2 (p<0.05). CONCLUSION: There was significant errors in measuring of the intravesical pressure during urodynamic study. These factors might be posture, spasticity of hip flexors, and expelling of the catheter in urodynamic study.

Change of Intra-abdominal Pressure on Daily Activities in Patients with Spinal Cord Injury

PURPOSE: To evaluate the change of intra-abdominal pressure related with intravesical and intrarectal pressure in patients with spinal cord injury according to daily activities and postural changes which make the abdominal pressure elevated. MATERIALS AND METHODS: Ten subjects with lower thoracic and lumbar spinal cord injury were enrolled. Their mean age was 38 years. The urodynamic study was performed and the intravesical and the intrarectal pressures were measured with a double lumen catheter and a intrarectal probe. The intravesical and the intrarectal pressure were obtained during patient's speech, sneeze, cough, valsalva and various postural changes with supine to decuitus, decubitus to supine, supine to sit, and sit to supine according to empty and full bladders, respectively. RESULTS: The order of higher intravesical and intrarectal pressure rise during various maneuvers were valsalva, sneeze, supine to sit and cough, respectively. Higher correlation coefficient between the intravesical and intrarectal pressures were noted during cough, sneeze, valsalva and supine to sit in empty bladder than full one. CONCLUSION: These results demonstrated that the intravesical and intrarectal pressures were influenced by daily activities and postural changes of increasing the intra-abdominal pressure. The intrarectal pressures according to daily activities such as cough, sneeze, valsalva and postural change were significantly related with intravesical pressures.