Muscle inhibition and motor unit behaviour after knee arthroplasty
Research type
Research Study
Full title
Short-term changes in arthrogenic muscle inhibition and the underlying motor unit activity following knee arthroplasty
IRAS ID
306712
Contact name
Jakob Skarabot
Contact email
Sponsor organisation
Loughborough University
Duration of Study in the UK
1 years, 5 months, 25 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, damage, swelling, and inflammation reduce the signal from the brain to muscle, which leads to inhibition and muscle weakness. Many patients with end-stage osteoarthritis undergo a knee replacement surgery. The replacement of the knee often results in increased inhibition and decreased strength, followed by better mobility and strength after some months of rehabilitation. It is suspected that this may be due to changes in joint pain, swelling and inflammation that occur after the knee replacement. Investigating changes in inhibition and muscle strength after knee replacement therefore provides a way to study causes of muscle inhibition that is often seen in knee osteoarthritis.
In this study, we will monitor changes in muscle inhibition, joint pain and swelling after knee replacement surgery. We will measure changes before the surgery, and then at 1, 3 and 6 months after. 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
East Midlands - Leicester South Research Ethics Committee
REC reference
23/EM/0055
Date of REC Opinion
23 Feb 2023
REC opinion
Further Information Favourable Opinion