Electrical Muscle Stimulation (EMS) Versus Standard Physiotherapy for Quadriceps Recovery Following Total Knee Replacement

This study will investigate whether adding electrical muscle stimulation (EMS) to standard physiotherapy helps preserve thigh muscle and improve recovery after knee surgery.

Pain, swelling and reduced activity after surgery can make it difficult to activate the quadriceps muscles at the front of the thigh. These muscles straighten the knee and support everyday activities such as standing, walking and climbing stairs. Muscle weakness and loss of muscle volume can delay rehabilitation. EMS delivers small electrical pulses through pads placed on the skin to make these muscles contract. It may therefore support muscle activation during recovery, when voluntary exercise can be difficult.

This prospective, randomised, controlled clinical trial will be conducted at one centre. The planned sample is 60 adults aged 18 years or older undergoing elective surgery on one knee. Participants will provide written informed consent before joining the study. After surgery, they will be assigned by chance to one of two groups, with 30 participants in each group.

All participants will receive standard physiotherapy and routine post-operative care. The intervention group will also use a portable Regen EMS device at home. Participants will receive training in operating the device and positioning the pads on the thigh, approximately 20 cm above the surgical wound. They will be asked to complete five 10-minute sessions each day. The comparison group will receive standard physiotherapy alone.

The primary outcome is the percentage change in quadriceps muscle volume in the operated leg, measured using magnetic resonance imaging (MRI) before surgery and six weeks afterwards. Researchers will compare the average percentage change between the two groups to assess whether adding EMS helps preserve muscle volume.

The study will also assess knee function using the Oxford Knee Score and Knee Society Score, alongside pain and satisfaction with recovery. These assessments will help establish whether changes in muscle volume are accompanied by differences in symptoms and function.

The research team will monitor EMS use, complications and any unwanted effects, including skin irritation or discomfort. EMS treatment may be adjusted, paused or stopped if necessary, while participants continue to receive appropriate standard care.

The findings will provide preliminary evidence about the effects of EMS on muscle preservation and early recovery after knee surgery, and help inform the design and sample size of a larger clinical trial.