Fig 1.
Experimental setup of elbow extension tasks and placement of electrodes on the medial, lateral, and long heads of the triceps brachii.
Amp, amplifier.
Fig 2.
Placement of surface electrodes on the medial, lateral, and long heads of the triceps brachii (TB).
Fig 3.
Representative B-mode ultrasound images.
A) The original image. B) An image with information regarding the medial head of the triceps brachii (TB-Med) of a male subject. The electrode is 1 cm long and 0.5 cm high, and the long axis length of the TB-Med muscle is 3.1 cm.
Fig 4.
Comparisons of normalized root mean square (RMS) of electromyographic signals and normalized isometric maximum voluntary contraction (MVC) force relationships with respect to the medial (TB-Med), lateral (TB-Lat), and long (TB-Long) heads of the triceps brachii at 60°, 90°, and 120° of extension.
††, P < 0.01 vs TB-Lat; a, P < 0.001 vs other muscles.
Table 1.
Exerted force and joint angle during elbow extension tasks.
Fig 5.
Comparisons of normalized root mean square (RMS) of electromyographic signal and normalized isometric maximum voluntary contraction (MVC) force relationships with respect to joint angles of 60°, 90°, and 120° of extension for the medial (TB-Med), lateral (TB-Lat), and long (TB-Long) heads of the triceps brachii.
†, P < 0.05, ††, P < 0.01 vs 60°; *, P < 0.05, **, P < 0.01, vs 90°.
Fig 6.
Sum of difference for the medial (TB-Med), lateral (TB-Lat), and long (TB-Long) heads of the triceps brachii between normalized root mean square (RMS) of electromyographic signal and normalized isometric maximum voluntary contraction force relationships at 60°, 90°, and 120° of extension.