Efficacy of hot-water immersion for targeting joint pain in patients with mild-moderate osteoarthritis

INTERVENTION: All participants will complete 2 water immersion sessions and a control session (in a randomised order): 1) 30‐min whole‐body hot‐water immersion (40°C; chest depth), 2) 30‐min lower‐limb hot‐water immersion (40°C; below knee depth). There will be a 4‐day washout between exposures. 1. 30‐min whole‐body hot‐water immersion (40°C) Location: School of Physical Education, Sport and Exercise Sciences Aquatic Facility (University of Otago, Dunedin). Supervision: This session will be supervised by an American College of Sports Medicine (ACSM) registered clinical exercise physiologist (CEP), and the primary investigator (PI) or a research assistant; all supervising researchers are first aid trained. Attendance and session particulars (e.g., physiological indices etc.) will be recorded at each session by the supervising researcher. Exposure: Participants will complete a single 30‐min hot water immersion session in 40 °C water. Participants will be seated upright with water approximately nipple level. Duration: 30 min. 2. 30‐min lower‐limb hot‐water immersion (40°C) Location: School of Physical Education, Sport and Exercise Sciences Aquatic Facility (University of Otago, Dunedin). Supervision: This session will be supervised by an American College of Sports Medicine (ACSM) registered clinical exercise physiologist (CEP), and the PI or a research assistant; all supervising researchers are first aid trained. Attendance and session particulars (e.g., physiological indices etc.) will be recorded at each session by the supervising researcher. Exposure: Participants will complete a single 30‐min hot water immersion session in 40 °C water. Participants will be seated upright with water approximately below knee level. Duration: 30 min. CONDITION: Musculoskeletal ‐ Osteoarthritis osteoarthritis; ; osteoarthritis PRIMARY OUTCOME: Joint pain[Assessed via 0‐10 Numeric pain scale Pre‐exposure, during exposure (every 10 mins), immediately post‐completion of exposure, 1 hr post‐completion of exposure, 2 hr post‐completion of exposure, 3 hr post‐completion of exposure, before bed, upon waking and 1 hr after waking.] SECONDARY OUTCOME: Blood pressure [Assessed via ausculatory method (using sphygmomanometer and stethoscope). Pre‐exposure, during exposure (every 10 mins) and immediately post‐completion of exposure.] Heart rate[Assessed via chest strap Pre‐exposure, during exposure (every 10 mins) and immediately post‐completion of exposure.] Physical activity[Assessed via accelerometry Across the 24‐h post‐completion of exposure.] INCLUSION CRITERIA: ‐ Has mild‐moderate osteoarthritis; ‐ Patient gives written consent; ‐ Patient is able to travel to the study centre to complete all sessions