Knee osteoarthritis produces degeneration and joint wear that greatly affects the patient's proprioceptive system increasing instability. After total knee arthroplasty intervention, it is recommended that the patient performs a rehabilitation procedure to minimize deficits caused by surgery. In this job it is essential to insist on the importance of recovering balance after total knee arthroplasty intervention, and assess a specifically designed protocol to restore its function. An intervention which includes a dynamometric platform as a training method was proposed. The randomized clinical trial compared a control group that performed balance exercises on parallel bars, unstable plates, ramps and stairs against an experimental group that included dynamometric platforms training as a differentiator.

Inclusion Criteria:

• Age between 65 and 85.
• Subjects with knee osteoarthritis that have not been operated before.
• Patients operated with the same total replacement prosthesis.
• Patients operated with the same surgical procedure.
• Time before intervention over 4 weeks.
• Time to start rehabilitation after surgery must be less than 4 weeks.
• The Result in Berg scale must be greater than 21, indicating a medium-low risk of falling.
• the Result of the Mini-Mental State Examination must be equal or greater than 20, which means they do not have moderate or severe cognitive impairment.
• Once the informed consent is read and explained, patients must accept and agree to participate in the study.

Exclusion Criteria:

• Patient does no accept sign the informed consent.
• Patient with morphological alterations hip or ankle (also knee).
• Patient that presents knee flexion out of the range between 70 ° and -20 ° because of the risk posed to suffer a fall.
• Patient with suspected deep vein thrombosis.
• Patient with post-surgical infection of the operated knee.
• Patient with psychiatric disorders: depression, anxious syndrome, etc.
• Patient with pathology of central origin (i.e. cerebellar) that could interfere with the results of the test of balance or strength
• Patient with vestibular pathology that could interfere with the results of the test of balance