The study included patients who underwent TKA surgery in the Hospital de Clínicas de Porto Alegre (HCPA) and met the study eligibility criteria. The sample was randomly divided into experimental group, which received conventional physical therapy associated with the application of TENS, and control group, which held only conventional physical therapy, both on the first day after the surgery. The pain level, the range of motion of the operated knee and the Administration of morphine.
The experimental group received TENS application held by two self-adhesive electrodes size 5x9cm positioned parallel to the lumbar spine, on the nerve roots L3, L4 and L5. TENS was applied in conventional mode, emitting a pulsed biphasic, symmetrical rectangular wave with frequency of 100 Hz and pulse duration of 100 µs, for 30 minutes. The intensity was set according to the tolerance of the patient and was gradually increased during the application. The device used was the Neurodyn II model, by Ibramed.
Subsequently, the conventional physical therapy was performed, with the use of the CPM device and performing exercises. The CPM device was used for 30 minutes, and realized continuous passive flexion and extension of the operated knee. The amplitudes of these movements were gradually increased in accordance with the tolerance of the patient. The device used was Spectra model, by Kinetec.
Then, the patients realized active exercises of plantar flexion and dorsal flexion of the ankles and adduction and abduction of the hips, isometric exercises of flexion and extension of the operated knee and active exercises of flexion and extension of the non-operated knee. All exercises were performed in 10 repetitions, with the patient positioned in the supine position in the bed.
The control group received only conventional therapy consisting of the use of the CPM device in the operated leg and the exercises in both lower limbs, identical to those performed in the experimental group.