ABSTRACT
The objective of this study was to evaluate the presence of progressive postpoliomyelitis muscle weakness (PPMW) in affected individuals 20 to 40 years after the initial polio infection. Over a three-year period, the isometric and isokinetic strength of the quadriceps femoris muscle was studied in seven symptomatic patients with previous poliomyelitis (mean = 38.3 years from infection) to determine if quadriceps strength decreased during the three years. Each patient had a quadriceps affected by polio on one side and a clinically nonaffected quadriceps on the contralateral limb. The maximal isometric force and the peak isokinetic force of the affected quadriceps (AQ) and nonaffected quadriceps (NQ) muscles were tested on a computerized isokinetic dynamometer machine at six-month intervals. Isometric force increased significantly, by 29% per year (p less than .02) in the AQ and by 14% per year (p less than .05) in the NQ. Paired analysis to determine the change in strength between the affected and nonaffected muscles for the isometric data showed a mean nonsignificant increase in the AQ of 14% per year (p = .01). The change in peak isokinetic force demonstrated a significant increase in the AQ of 35% per year (p less than .05); whereas, the NQ peak isokinetic force increased 15% per year which was not statistically significant. Paired analysis to determine the change in strength between the affected and nonaffected muscles for the isokinetic data showed a nonsignificant relative increase in the AQ of 20% per year (p less than .06).(ABSTRACT TRUNCATED AT 250 WORDS)
