Multimodal Treatment of Knee Osteoarthritis: Therapeutic Exercise and Noninvasive Neuromodulation (NESA) Versus Therapeutic Exercise and Transcutaneous Electrical Nerve Stimulation (TENS) in People Over 60 Years of Age.

Multimodal Treatment of Knee Osteoarthritis: Comparison of the Combination of Therapeutic Exercise and Noninvasive Neuromodulation (NESA) Versus Therapeutic Exercise and Transcutaneous Electrical Nerve Stimulation (TENS) on Pain, Function, and Mental Health in People Over 60 Years of Age.

To analyze the effects of therapeutic exercise combined with noninvasive neuromodulation (NESA) or transcutaneous electrical nerve stimulation (TENS) on improving clinical symptoms such as joint pain and stiffness, as well as its impact on the functionality, mental health, and quality of life of people over 60 years of age with knee osteoarthritis.

A single-blind, randomized clinical trial with two intervention groups will be conducted. A pretest-posttest design will be used to evaluate individuals over 60 years of age. Participants will be divided into two groups: one group will receive an 8-week therapeutic exercise program combined with noninvasive neuromodulation (NESA); and the other group will receive the same therapeutic exercise program combined with transcutaneous electrical nerve stimulation (TENS) for 8 weeks. Variables will be measured for both groups using the same validated tools and by the same researchers to avoid information bias and differential misclassification. Assessments will be conducted at the beginning of the intervention and immediately after its completion. The results will be recorded in a database for analysis.

For the independent variables, sociodemographic characteristics will be taken into account. The outcome variables will be divided by domain; pain will be assessed using the Numerical Pain Rating Scale (NPRS), which measures pain intensity. To assess the symptoms and functional capacity associated with knee osteoarthritis, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) will be used.

For the physical and functional assessment, the Timed Up and Go Test (TUG) will be used to assess functional mobility, balance, and agility. The Short Physical Performance Battery (SPPB) will be used to evaluate balance, gait, and strength/endurance. Balance and gait will also be assessed using the Tinetti Scale. Knee mobility will be measured with a mobile goniometry/inclinometer in flexion and extension. For strength, a dynamometer will be used to measure isometric strength of major knee movements.

Among the psychosocial factors, catastrophizing will be measured with the PCS (Pain Catastrophizing) and kinesiophobia with the abbreviated version of the TSK-11 (Tampa Scale for Kinesiophobia). Fear of falling will be assessed using the Falls Efficacy Scale-International (FES-I).

Quality of life will be measured using the Knee and Hip Osteoarthritis Quality of Life (OAKHQOL) questionnaire. Sleep quality will be measured using the Pittsburgh Index. The Hospital Anxiety and Depression Scale (HADS) will be used for anxiety and depression. Autonomic regulation will be assessed using heart rate variability.

All variables will be measured pre- and post-intervention. As a result, a multimodal treatment is expected to significantly improve clinical symptoms associated with knee osteoarthritis, especially joint pain and stiffness. Additionally, the effectiveness of noninvasive neuromodulation (NESA) will be compared with transcutaneous electrical nerve stimulation (TENS), both in combination with therapeutic exercise. It is also expected to improve functionality, mental health, quality of life, and associated psychosocial factors in people over 60 years of age with knee osteoarthritis. Once the intervention is completed, a final evaluation will be conducted, and the comparative process will determine whether there are significant differences compared to the initial results.

Inclusion Criteria:

• Individuals over 60 years of age.
• Diagnosis of knee osteoarthritis in at least one knee according to the clinical criteria of the American College of Rheumatology.
• Ability to walk independently without the need for assistive devices.
• No medical contraindications to physical exercise or the application of noninvasive neuromodulation (NESA).
• Ability to understand and sign the informed consent form to participate in the study.

Exclusion Criteria:

• Present medical contraindications to physical exercise or the application of noninvasive neuromodulation (NSA) (pacemaker, epilepsy, internal bleeding, acute febrile processes, acute thrombophlebitis, and/or phobia of electricity).
• Present active oncological diseases or systemic autoimmune diseases.
• Present severe psychiatric or neurological disorders that limit understanding and collaboration in treatment.
• History of any surgery or fracture of the affected lower limb in the last 3 months.
• Presence of severe gait or balance difficulties that impede the performance of the proposed exercises.
• Simultaneous participation in other clinical trials.