A COMPARISON OF SYMPTOMS BETWEEN SWEDISH AND AMERICAN POSTPOLIO INDIVIDUALS AND ASSESSMENT OF LOWER-LIMB STRENGTH - A 4-YEAR COHORT STUDY

A cohort study with initial and 4-year follow-up evaluations was perfo rmed in 78 post-polio volunteers aged 31-65 Sears at the time of enrol ment in the study, which was made to compare post-polio individuals Li ving in Sweden and the United States, to determine whether lower limb musculature becomes weaker over time, and to determine whether individ uals with complaints of post-polio syndrome, new weakness, fatigue, wa lking or stair climbing difficulty were weaker or lost more strength o ver a 4-year interval than those individuals without such complaints, Dynametrically-measured knee extensor and flexor strength and question naire data were obtained initially and 4 years later. The tao cohorts were fairly similar, though they differed in weight gain, The American s gained significantly (p < 0.05) more weight than the Swedish subject s, Both groups lost significant (p < 0.05) knee extensor strength (app roximately 8%), but the loss was not significantly (p > 0.05) differen t between the groups, Knee flexor strength did not change significantl y (p > 0.05) over time. Subjects acknowledging new strength loss were not significantly (p > 0.05) weaker than those denying strength loss; however, they lost significantly (p < 0.05) more isometric knee extens or strength than the other individuals, Subjects acknowledging new fat igue, walking or stair climbing difficulty were significantly (p < 0.0 5) weaker in both muscle groups than those without such complaints. Su bjects acknowledging post-polio syndrome were significantly (p < 0.05) weaker than those denying this symptom, but the amount of loss of str ength over time was not significantly (p > 0.05) different, We conclud e that the two cohorts were quite similar, Knee extensor strength decr eased during the study interval, Individuals acknowledging post-polio syndrome had weaker knee extensor musculature, Subjects with new fatig ue, walking difficulty, or stair climbing difficulty were weaker in bo th the knee extensors and the knee flexors than the other subjects, Su bjects reporting new muscle weakness also had a greater decline in iso metric knee extensor strength during the study interval than those wit hout such complaint.