Isolated Resistance Training and Neuromuscular Electrical Stimulation in Patients With Femoral Intra Aortic Balloon Pump.

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.