Clinical Research Directory

The hip range of motion (ROM) will be fixed at 45 degrees due to the limitation imposed by the femoral insertion of the intra-aortic balloon pump in both lower limbs to allow for a 45-degree knee extension ROM. Four sets of 10 knee extension repetitions will be performed with a 90-second rest interval between sets. The intensity (resistive load) will be set at 60% of the baseline load, calculated using the one-repetition maximum (1RM) test and increased by 10% after every 5 interventions.

For NMES, two electrodes (area of 5 x 9 cm) will be positioned perpendicular to the muscles of the femoral quadriceps. The parameters of NMES will remain fixed throughout the study: pulsed, biphasic current, with a frequency of 35Hz, pulse width of 1000µs, on-time of 7 seconds (with 3 seconds of rise, 1 second of sustainment, and 3 seconds of descent), and off-time switched off. These settings allow the onset of NMES to be synchronous with the start and end of hip extension for simultaneous execution with resistance exercises and a total of 40 stimulations. The intensity will be gradually adjusted until evoked contractions of grade 4 to 5 (partial muscle recruitment and total muscle recruitment) or the maximum intensity tolerated by the patient is achieved.