Physiological and clinical effects of low-intensity blood-flow restricted resistance exercise compared to standard rehabilitation in adults with knee osteoarthritis-Protocol for a randomized controlled trial

PLoS One. 2023 Dec 14;18(12):e0295666. doi: 10.1371/journal.pone.0295666. eCollection 2023.

Abstract

Introduction: Osteoarthritis (OA) is a common disease with high socioeconomical costs. In Denmark, standard rehabilitation (SR) consists of a combination of patient education and supervised physical exercise involving a standardized neuromuscular training program. As an evidence-based alternative, high-load (>70% 1RM) resistance training (HIRT) has shown positive rehabilitation effects in knee-OA but may not be tolerated in all patients (~25%) due to knee joint pain. However, low-load resistance training (20-40% 1RM) with concurrent partial blood-flow restriction (BFR) appears to produce effects similar to HIRT yet involving reduced joint pain during and after exercise. The aim is to examine the effect of low-load BFR training compared to SR on pain, thigh muscle mass and muscle function in adults with knee-OA. We hypothesize that 12 weeks of BFR will lead to superior improvements in pain, muscle mass and mechanical muscle function compared to SR.

Methods and analysis: 90 participants diagnosed with radiographic knee-OA will be randomized to either BFR or SR twice a week for 12 weeks. BFR will consist of two selected lower limb strength exercises performed with an inflated pneumatic occlusion cuff. Intervention procedures in SR consist of a full 8 weeks GLA:D course followed by 4 weeks of team group training. Primary outcome variable is the change in KOOS-Pain subscale from baseline to 12 weeks. Secondary outcome variables are changes in pain sensitivity, functional performance, muscle mass and mechanical muscle function. Intention-to-treat and per-protocol analyses will be conducted. One-way analysis of variance will be performed to evaluate between-group changes. Pre-to-post intervention comparisons will be analyzed using a mixed linear model. Regression analysis will be performed to evaluate potential associations between selected outcome variables.

Publication types

  • Clinical Trial Protocol

MeSH terms

  • Adult
  • Arthralgia / complications
  • Exercise Therapy / methods
  • Humans
  • Muscle Strength / physiology
  • Osteoarthritis, Knee* / complications
  • Pain
  • Randomized Controlled Trials as Topic
  • Resistance Training* / methods

Grants and funding

This work was funded by: - The A.P. Moller Foundation (grant number 20-L-0186) (BS) (https://www.apmollerfonde.dk) - The Health Foundation (grant number 20-B-0214) (BS) (https://helsefonden.dk) - The Danish Rheumatism Association (grant number R181-A6356) (FEJ) (https://www.gigtforeningen.dk) - The Physiotherapy Practice Foundation (grant number R176-A4095) (BS) (https://www.fysio.dk/fafo/fonde/praksisfonden) - Foundation of the National Health Security System (Fonden for Faglig Udvikling af Speciallægepraksis) (Denmark) (grant number A2387) (FEJ) (https://rltn.dk/fonde/praksisfondene/fonden-for-faglig-udvikling-i-speciallaegepraksis) - The Aase and Ejnar Danielsen's Foundation (grant number 18-10-0559) (SKH) (https://danielsensfond.dk) The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.