Jc. Agre et al., A COMPARISON OF SYMPTOMS BETWEEN SWEDISH AND AMERICAN POSTPOLIO INDIVIDUALS AND ASSESSMENT OF LOWER-LIMB STRENGTH - A 4-YEAR COHORT STUDY, Scandinavian journal of rehabilitation medicine, 27(3), 1995, pp. 183-192
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.