Pilot Study-Estimated VO2max via Modified Harvard Step Test (MHST) in Anterior Cruciate Ligament Injury Patients Undergoing Pre-Op Rehabilitation

Introduction: Anterior Cruciate Ligament (ACL) injury ranging from partial to full thickness tear causes much dysfunction physically and psychologically. It affects both daily & sporting activities with potential of creating long term complications such as post-traumatic osteoarthritis of knee, functional limitations, increase in body mass index (BMI) and loss of cardiorespiratory fitness. Cardiorespiratory fitness is an important indicator for functional and fitness capacity and VO2max is used to measure cardiorespiratory fitness. VO2max is the maximum rate of oxygen consumption during a vigorous exercise. Cardiopulmonary exercise testing is usually done on a treadmill with gaseous exchange system, a process that is time consuming, expensive and difficult to assess and not available in our public health setting. Modified Harvard step test is easy to do, cost friendly and allows mass testing to measure cardiorespiratory fitness (VO2max) however there are inadequate data on ACL injury and its influence on cardiorespiratory fitness using modified Harvard step test. Method: A prospective study was done using patients attending Sports Medicine Gym Hospital Tuanku Ja’afar 2023 and data from 20 patients who were undergoing pre-ACL reconstruction rehabilitation were evaluated. Patients were divided into two groups according to post trauma duration; (<6 months of injury and rehabilitation and >6 months injury and rehabilitation). Patients were required to do modified Harvard step test and translated into VO2max scores. Anthropometric data were also taken from patients. Results: The mean age for our study is 21.9±4.3 years. The mean VO2max for the entire participant was 43.2ml/kg/min. Mean VO2max for groups <6 months injury rehabilitation and >6 months injury rehabilitation was at 35.4±1.8 ml/kg/min and 49.0± 5.8ml/kg/min respectively. We report difference in both groups VO2max Conclusion: Cardiorespiratory fitness is often reduced during earlier phase of injury due to inability to perform aerobic exercises. Progressive rehabilitation can improve cardiorespiratory fitness, aid in patients return to sports and reduces morbidity post operatively. Modified Harvard step test is a reliable and cost-effective method to test VO2max. It is also important to increase cardiorespiratory fitness to maintain healthy BMI.