Effects of supine positioning and fracture post placement on the perineal countertraction force in awake volunteers.

ABSTRACT

An instrumented traction post was used to determine the magnitude and direction of the countertraction force applied to the perineum of 15 awake volunteers for a series of 12 positions used in fracture surgery and compared with their corresponding neutral position controls. The results demonstrated that adduction of the affected limb and abduction of the contralateral limb applied the greatest force to the perineum with ipsilateral and contralateral placement of the fracture post. These two maneuvers increased the perineal countertraction force 80% above their respective neutral readings. Abduction of the affected limb reduced the traction force by 50% with ipsilateral and contralateral placement of the fracture post. Flexion-abduction-external rotation of the contralateral leg reduced the forces applied to the perineum by 60% when the fracture post was placed contralateral to the affected limb. Contralateral placement of the post decreased the perineal countertraction force 46% below the value for ipsilateral post placement for this maneuver. Internal and external rotation of the affected limb had no effect on the perineal countertraction force for either placement of the post. There was a significant decrease in the perineal forces for the neutral positions after adduction of the affected limb and abduction of the contralateral limb with ipsilateral placement of the post, indicating that the volunteers shifted on the fracture table in response to pain. There was no significant difference in the direction of the countertraction force for the various positions.(ABSTRACT TRUNCATED AT 250 WORDS)