Mediators of muscle inhibition in knee osteoarthritis (version 1)

• Research type

  Research Study

• Full title

  The factors mediating arthrogenic muscle inhibition in knee osteoarthritis

• IRAS ID

  321959

• Contact name

  Jakob Skarabot

• Contact email

  J.Skarabot@lboro.ac.uk

• Sponsor organisation

  Loughborough University

• Duration of Study in the UK

  1 years, 3 months, 29 days

• Research summary

  People with knee osteoarthritis typically have weaker muscles that extend the knee, which are important for mobility and thus independence and quality of life. This weakness is because of muscle inhibition, which is the reduced ability of the brain to activate all muscle fibres within the muscle. This muscle inhibition is known to cause muscle weakness and may be preventing effective muscle strengthening and rehabilitation. It has been suggested that joint pain, swelling, and inflammation reduce the signal from the brain to muscle, which leads to inhibition and muscle
  weakness.
  Patients with knee osteoarthritis that have clinically meaningful swelling are often treated with joint injections. In this process, swelling will first be removed, then a patient will receive an injection containing local anaesthetic (for pain) and a corticosteroid (to manage inflammation).

  In this study, we will monitor the changes in muscle function and the electrical signal produced by muscles after the removal of swelling, and then again after a joint injection. This will allow us to find out which factors are the most important in causing muscle inhibition in knee osteoarthritis.

  The level of inhibition will be measured by stimulating the nerve that activates the knee extensors during muscle contractions. During muscle contractions, we will also measure the electrical signal that control the muscle to investigate the detailed differences in muscle activation signal. This will be done by placing electrodes on the skin covering the muscle (surface electromyography) or inserting a very thin needle electrode (26 gauge, smaller than a blood sampling needle; intramuscular
  electromyography) into the muscle. Ultrasound will be used to measure swelling and questionnaires will be used to determine joint pain.

• REC name

  London - Hampstead Research Ethics Committee

• REC reference

  23/PR/0399

• Date of REC Opinion

  22 May 2023

• REC opinion

  Further Information Favourable Opinion