Multiple Sessions of One-Legged Recumbent Cycle Ergometer Exercise Improved Pedaling Rate and Knee Range of Motion in a Middle-Aged Man after Hip Disarticulation: A Clinical Case

Background: This case evaluates the short-term training effects with alterations in pedaling rate (PR) and its relationship to knee range of motion (KROM) after multiple sessions of one-legged recumbent cycle ergometer exercise (1LREx) in a patient after hip disarticulation (HD). Case: A 44-year-old male patient had left HD due to osteosarcoma. He performed unilateral right 1LREx at 10 W with a self-controlled freely chosen PR until exhaustion. Multiple 1LREx sessions (maximum 4-5 sessions/day) were performed over 6 consecutive days from day 15 post-HD. PR and right KROM in the downstroke (pushing) and upstroke (pulling) pedal phases were determined continuously using a goniometer placed between the thigh and lower leg. The PR time-course during 1LREx indicated differences among multiple daily sessions but tended to be higher and more stable at steady-state over the study period (average ± SD PR and its coefficients of variability, 33.2 ± 5.3 revolution per minute (rpm) and 28.0% on Day 1 versus 43.0 ± 3.0 rpm and 12.5% on Day 6). The time-course of KROM was similar among multiple sessions during each day; however, the average KROM over all sessions in a day tended to increase over the study period (51.0 ± 1.2° on Day 1 vs. 78.0 ± 2.3° on Day 6). Mean KROM in the downstroke or upstroke pedal phases during each session showed a significant positive linear correlation (total of 27 sessions, p < 0.05) with mean PR. Conclusion: After HD, short-term one-legged trainability with multiple 1LREx resulted in increased KROM and PR with uniformly faster PR with whole leg exercising in the sagittal plane