To stay strong, patients should do some strength training at least twice a week. However arthritic pain can limit walking and activity. The wait for knee surgery can be long, which can lead to loss of muscle strength. Patients who need a new knee joint tend to be older. If older people do not exercise and become weak, they tire easily, and may take longer to recover after surgery. Patients recover faster after having a new knee joint if their leg muscles are strong. This is why exercise before surgery can help people to make the most of their new joint. Patients come to a joint school where the investigators show them exercises and advise how to get ready for surgery. Patients are given a sheet of pictures and prompts for each exercise but the investigators know that some people don't do the exercises that they are given. Exercises are more likely to be done if they are fun, if people can see they make a difference, if they know what to do, and if their physiotherapist can check what they are doing.

To stay strong, patients should do some strength training at least twice a week. However arthritic pain can limit walking and activity. The wait for knee surgery can be long, which can lead to loss of muscle strength. Patients who need a new knee joint tend to be older. If older people do not exercise and become weak, they tire easily, and may take longer to recover after surgery. Patients recover faster after having a new knee joint if their leg muscles are strong. This is why exercise before surgery can help people to make the most of their new joint. Patients come to a joint school where the investigators show them exercises and advise how to get ready for surgery.

Patients are given a sheet of pictures and prompts for each exercise but the investigators know that some people don't do the exercises that they are given. Exercises are more likely to be done if they are fun, if people can see they make a difference, if they know what to do, and if their physiotherapist can check what they are doing.

Patients come to a joint school where the investigators show them exercises and advise how to get ready for surgery. Patients are given a sheet of pictures and prompts for each exercise but the investigators know that some people don't do the exercises that they are given. Exercises are more likely to be done if they are fun, if people can see they make a difference, if they know what to do, and if their physiotherapist can check what they are doing.

Kemtai is an online exercise program which shows how to do the exercises and tells the patient how to move in the right way if they are not doing it correctly. The patient gets a score to show how well they are doing the exercise. This makes the task fun. Their physio can see when they have exercised and if they are making progress.

The investigators will perform a small study called a pilot randomised controlled trial to find out how many people are eligible to take part, how many agree to take part, and the reasons for not being able to do so.

This study will tell us how many patients can use online programmes and have access to computers, tablets or smartphones that can run the Kemtai programme. The investigators can provide data if someone is able to take part but are unable to provide a smartphone or tablet. This study will tell us how many patients would need data or devices to take part in a bigger study.

The investigators also want to know if there are any differences in amount of exercise done before surgery, and in length of stay in hospital, amount of physiotherapy, pain, movement and quality of life after surgery between those who used a paper exercise prompt sheet and those who used an online exercise programme (Kemtai).

Joint school physios will identify who is eligible for the study. If interested, the patients will be given a leaflet and invited to watch a presentation about the study. Those patients who wish to take part will be asked to give informed consent and asked to fill in three questionnaires (Oxford knee score, EQ-5D-5L and the visual analogue scale). Patients will also be asked for some information (name, address, gender, ethnic group, e-mail, and year of birth) to help the investigators compare the two groups. A computer programme will inform the investigators if the patient should have Kemtai access or a sheet of exercises. No more physiotherapy is given until after the patients have their new joint. The investigators offer help to access the Kemtai programme and will note what help is needed.

After surgery, the number of physio contacts and the number of hours in hospital will be counted. The number of times that the patients exercised before surgery will be collected either from the exercise diary that contains the paper exercise list, or from the Kemtai programme. At six weeks after surgery patients will be contacted by phone and asked to give their scores for the three questionnaires again. A patient's time in the study stops at this point.

A team, which includes patients who have had new knee joints, will look at the results and decide how a larger study should be run.

Inclusion Criteria:

1. Adults aged ≥18 years.
2. Referred to Hull University Teaching Hospitals NHS Trust t for Knee Arthroplasty at either Castle Hill Hospital or Goole District Hospital and has access to pre operative resources offered by the joint school physiotherapists.
3. Has access to a device which is compatible with the operational requirements of the Kemtai programme.
4. Able to give informed consent.

Exclusion Criteria:

• Significant comorbid physical or mental illness considered by the investigator to either: prevent engagement in modified exercise; impair the participants ability to follow instructions place the participant at undue risk during exercise training adversely affect the recovery or rehabilitation trajectory

• Patients already involved in an exercise or rehabilitation study will be excluded from this study.
• Unwilling or unable to consent or complete study measures.
• Has insufficient understanding of English or the languages that are supported by the Kemtai programme and does not have someone who can translate.
• Is a prisoner
• Has had a total hip replacement within the previous 6 months.
• Is attending for revision of a previous knee replacement
• Is having a knee replacement due to a tumour
• Lacks visual acuity sufficient to follow stimuli on monitor or has someone who can give necessary verbal prompts
• Severe genu varum or genu valgum deformity which precludes the ability to exercise using the Kemtai programme.

We will share anonymised data with other researchers. Any request for data should be made to Dr Angela Green at Angela.Green28@nhs.net or Dr James P Hobkirk at James.Hobkirk3@nhs.net