Reach and Palmar Grasp in Tetraplegics With Neuromuscular Electrical Stimulation: Assessment and Training.

Prior to the kinematic captures, all patients selected in the study received 20 sessions of NMES therapy, twice a week, with 10 weeks of duration. The strengthening sessions plus training prior to the kinematic study of movement strategies has the objective to condition the paretic muscles to the functional activity.

Twenty sessions was divided in 10 sessions of strengthening and 10 sessions of the functional training of reaching and grasping assisted with electrical stimulation.

The strengthening sessions consisted of 20 minutes of electrical stimulation on triceps, extensor carpi radialis longus, extensor digitorum communis, lumbricalis, flexor digitorum superficialis and opponens pollicis muscles.

The functional training sessions was performed through movements the reach and palmar grasp with NMES of the several cylindrical and conical objects of different weights (30 minutes sessions). The NMES was used to facilitate movements of reach (triceps muscle), opening (extensor carpi radialis longus and extensor digitorum communis muscle), positioning (extensor carpi radialis longus, flexor digitorum superficialis and lumbricalis muscle), palmar grasp (extensor carpi radialis longus, flexor digitorum superficialis, opponens pollicis muscle) and releasing (extensor carpi radialis longus and extensor digitorum communis muscle). Since the temporal organization varied among tetraplegics, some of them required more time to some stages of the sequence.

For NMES, the eight-channel stimulator, controlled by a microcomputer was used with pulse frequency, 25 Hz; pulse duration, 300 milliseconds; on/off duration 2/2sec; maximum pulse width fixed at 250 microampere, and the amplitude individually adjusted to achieve the excitability threshold for each muscle. The amplitude was adjusted throughout the training, in order to produce the desired muscle contraction. This parameters was used in all of therapies and in the kinematic assessment. The stimulation was applied with self-adhesive surface electrodes taped to the skin.