Correlations between knee extensor strength measured by a hand-held dynamometer and functional performance in patients with chronic stroke

The aim of this study was to investigate the correlations between knee extensor strength of the affected lower limb in patients with chronic stroke and other functional performance tests. Ten subjects with post-stroke hemiparesis (10 males; 54.3 +/- 8.4 years old), who suffered from stroke for more than three years (duration of 8.7 +/- 4.5 years) participated in this study. Knee extensor strength was measured using a hand-held dynamometer. Gait velocity was assessed when performing a 5-metre walk (5MWV), and additional parameters [the 5-minute walking distance (5MWD), the functional reach test (FRT), a timed up-and-go test (TUG) and Berg balance scale (BBS)] were also assessed as parameters of functional performance in each subject. It was demonstrated that knee extensor strength had significant Pearson's r correlation with 5MV (r = 0.459, p < 0.05), FRT (r = 0.781, p < 0.01), TUG (r = -0.538, p < 0.01) and BBS (r = 0.758, p < 0.05). Therefore, knee extensor strength may be a moderate to good predictor of functional performance in patients with chronic stroke hemiparesis.