Abstract

The aim of the 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 3-yr period, the isometric and isokinetic strength of the quadriceps femoris was studied in 7 symptomatic patients with previous poliomyelitis (mean = 38.3 yrs from infection) to determine if quadriceps strength decreased during the 3 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 at 6-month intervals. Isometric force increased significantly, by 29 per year in the AQ and by 14 per year in the NQ. Paired analysis to determine the change in strength between the affected and nonaffected msucles for the isometric data showed a mean nonsignificant increase in the AQ of 14 per year. The change in peak isokinetic force demonstrated a significant increase in the AQ of 35 per year; whereas, the NQ peak isokinetic force increased 15 per year (nonsignificant). 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. It was concluded that both the isometric and isokinetic strength of the AQ muscle did not progressively decrease over a 3-yr period in this population of patients. Verf.-Referat