Standardized rescue training as part of an exercise program for knee osteoarthritis: proof of concept

Abstract

Purpose: Exercise is recommended as one of the primary treatments for patients with knee Osteoarthritis (OA) with known effects on knee pain, mobility, and function. Knee OA pain fluctuates and therefore previously published exercise programs suggest avoiding exercises if excessive knee pain is present. However, applying an exercise program that includes a standardized rescue program would allow the patients to attend an exercise session despite excess pain, and such approach could reduce the current pain intensity because general pain reduction is a known effect of exercise. Although there is a wealth of studies investigating the effectiveness of exercise in patients with knee OA, no such standardised rescue program has been described previously. The aim of this study was to asses if participants referred to a rescue program due to excessive pre-session pain would experience a decrease in pain after rescue exercise. Methods: We used data from a randomized trial of exercise therapy versus no attention (clinicaltrials.gov: NCT01545258). 31 participants were allocated to the exercise program in the underlying study. These participants exercised for approximately 1 hour 3 times per week for 12 weeks (i.e. 36 possible sessions) supervised by a trained physical therapist. Pre and post exercise pain was recorded using a numeric rating scale (NRS, from 0=no pain to 10=excruciating pain). The standardized exercise program consisted of 6 focus areas; core strength and control, hip stability, hip abductor strength, knee stability, quadriceps strengthening, and functional training applying the basic exercises into functional tasks. A rescue program was applied if the participant scored a pre-session knee pain of 5 NRS or higher. The rescue program was similar to the full program but excluded weight bearing activities and consisted of 15 minutes warm-up on an ergometer bike followed by 3 exercises: core stability, hip stability and hip strengthening. The 3 exercises were repeated after 5 minutes of cycling. Results: Of the 31 participants, 5 (16%) was referred to the rescue program between 2 and 8 times during the 12 week period; 2 were referred twice, 2 were referred four times, and 1 was referred eight times. The maximum number of consecutive rescue sessions was 3 times for one participant. In 15 rescue sessions (75%) the participants experienced a decrease in pain. On 4 occasions (20%) the participants experienced no change in pain intensity, and at 1 occasion (5%) a participant experienced an increase in pain intensity (from 6 NRS to 7 NRS). The mean pre-rescue pain intensity was 6.7 (min: 6; max: 9), and the mean post-rescue pain intensity was 3.9 (min: 0; max: 7). The average decrease in pain following a rescue session was 2.9 (min: -1; max: 9). Individual pre- and post rescue session pain ratings are shown in figure 1. Conclusion: Implementing a standardized rescue program is effective in terms of reducing pain intensity in case of excessive pre-session pain. We believe that the rescue program gives the participants a positive exercise experience despite having knee pain that would make conventional exercise unsafe. It is our belief that a rescue program helps increase adherence to an exercise program and hopefully translates into better self-administered exercise routines and habits.