Lower-limb muscle strength, static and dynamic postural stabilities, risk of falling and fear of falling in polio survivors and healthy subjects.

This study investigated the association between preserved lower-limb muscle strength, dynamic and static postural stability, risk of falling, and fear of falling in polio survivors. We also investigated whether these clinical features differ between polio survivors and healthy controls.

Methods

This quasi-experimental study enrolled 16 polio survivors (13 underwent a complete-case analysis) and 12 age- and sex-matched healthy controls. Participants were assessed by the manual muscle test, Berg Balance Scale, force platform posturography, and Falls Efficacy Scale. Between-group mean differences with confidence intervals (MD, CI 95%) and Spearman's ρ are reported.

Results

Compared to healthy controls, polio survivors presented reduced muscle strength (MD = -13, CI 95% -16 to -9 points), lower dynamic postural stability (MD = -14, CI 95% -19 to -8 points), and increased fear of falling (MD = 14, CI 95% 10-18 points) (all P < 0.001). In polio survivors, lower-limb muscle strength was correlated with dynamic (ρ = 0.760) and static postural stability (ρ = 0.738-0.351), risk of falling (ρ = -0.746), and fear of falling (ρ = -0.432). Dynamic postural stability was correlated with risk of falling (ρ = -0.841), fear of falling (ρ = -0.277), and static postural stability (ρ = -0.869 to -0.435; ρ = -0.361 to -0.200, respectively). Risk and fear of falling were also correlated (ρ = 0.464). Discussion: Polio survivors exhibited impaired dynamic postural stability but preserved static stability and increased risk of falling and fear of falling. Preserved lower-limb muscle strength, postural stability, fear of falling, and risk of falling are associated clinical features in this population.