Muscle strength was assessed by the handgrip strength, which was measured using a digital dynamometer (TKK 5101 Grip-D; Takei, Tokyo, Japan) with the patients in the sitting position. Maximal isometric voluntary contractions of both hands were measured for 3 s each, with the elbow joint flexed at 90°. Handgrip strength was measured twice on each side, and the highest value (expressed as the absolute value in kilograms) was used in the analyses.