Age-induced modifications in postural control and lower limb strength

Abstract

(192/250) The postural sway during tasks of increasing difficulty and the isokinetic and isometric strength of knee extensors-flexors and ankle plantar flexors-dorsiflexors muscles were evaluated through ages. Sixty participants (27 women) were divided in 5 age groups (group 1: 21-30 years, group 2: 31-40 years, group 3: 41-50 years, group 4: 51-60 years and group 5: 61-75 years). They performed 3 static balance tasks with the eyes open and closed on a force plate: Normal Quiet Stance (30 s), Tandem Stance (20 s), and One Leg Stance (10 s). Posture was quantified using several Center of Pressure (CoP) variables in Anterior/Posterior and Medio/Lateral direction). They also performed maximal isokinetic and isometric knee extensions-flexions and plantar flexionsdorsiflexions. The CoP velocity increased gradually from group 1 to group 5. When narrowing the base of support, the CoP excursion increased for all age groups (P<0.05). Knee and ankle muscles strength decreased gradually from group 1 to group 5. During all postural tasks, moderate (-0.39 to -0.61) correlations between CoP velocity and isometric strength of knee and ankle muscles were observed. Knee and ankle strength can be considered as predictors of static balance control, especially when postural requirements relate to narrower stance.