UC San Diego

This thesis consists of a literature review describing the current standard of care and challenges in Total Knee Arthroplasty (TKA) and Total Hip Arthroplasty (THA), the potential application of lower body positive pressure (LBPP) in post-knee and hip surgery rehabilitation, and a feasibility study evaluating the ability of LBPP to ease the transition from seated to standing postures. LBPP is a method of simulating microgravity, causing a decrease in bodyweight by using positive chamber pressures to lessen body weight and load bearing. A study using the Five Times Sit to Stand (FTSTS) test to measure ease of movement and the Borg scale to determine physical exertion was conducted among 8 healthy participants (22.63 ± 1.06 years of age, 50% women). Subjects were placed within a LBPP machine, asked to perform the FTSTS test at baseline, report their exertion levels, then repeat the test at 6 chamber pressures (-25 mmHg, -20mmHg, -10mmHg, 10mmHg, 20mmHg, 25mmHg) in an alternating negative-positive pattern, beginning with a negative chamber pressure. Blood pressure, heart rate, and body weight were measured at all chamber pressures. Borg values were significantly lower at positive chamber pressures compared to negative chamber pressures. FTSTS times were faster at positive chamber pressures than at negative chamber pressures. Heart rate and blood pressure did not differ at positive chamber pressures from baseline measurements. LBPP could be a potential supplement to rehabilitative therapy for post-knee and hip surgery patients by lessening load bearing and exertion while not increasing heart rate and blood pressure, markers of cardiovascular stress.