Protocol for the Rucking-Related Assessment of Muscular, Psychological, and Biomechanical Contributors to Hip Pain and Cartilage Integrity in Female Military Personnel With Chronic Hip Pain (RAMP) Study

OBJECTIVE: The purpose of this protocol paper is to outline the aims and methods for the RAMP Study. The RAMP Study aims to 1) assess the impact of hip joint mechanics (hip joint contact forces), muscle function (hip abductor rate of torque development), and psychological health (pain self-efficacy) on changes in hip joint pain after a prolonged, loaded ruck and 2) evaluate the impact of hip joint mechanics, muscle function, and psychological health on changes in hip joint cartilage composition/integrity after a prolonged, loaded ruck in female military personnel with chronic hip joint-related pain. DESIGN: Single-group observational design METHODS: Females aged 18-35 years with chronic hip joint-related pain (≥ 3 months) without radiographic signs of hip osteoarthritis will be recruited. Participants will complete surveys (International Physical Activity Questionnaire, modified Harris Hip Survey, Pain Self-Efficacy Questionnaire), undergo a baseline hip MRI, and then complete a 30-minute loaded rucking (5km/hr; 33% of body weight) task in a 3-dimensional (3D) gait biomechanics lab. Following the rucking task, participants will undergo a post-intervention hip MRI and subsequent isometric hip flexor, extensor, abductor, and adductor muscle strength testing. RESULTS: A generalized linear mixed-effects model will be used. Anticipated results from the RAMP Study will be disseminated through peer-reviewed publications and conference proceedings. CONCLUSION: This study will guide a future evidence-based rehabilitation intervention to reduce hip joint pain and improve hip joint cartilage health.