This randomized controlled trial was designed to investigate the effects of craniosacral therapy on pain, heart rate variability, joint stiffness, physical function, quality of life, body image, kinesiophobia, and dynamic balance in adult patients with gonarthrosis. The primary research question is whether craniosacral therapy, when added to a standard home exercise program administered by physical therapists, is more effective than a home exercise program alone.

Participants will be randomly allocated into two groups. Both groups will perform a standardized home exercise program for six weeks. In addition, the experimental group will receive craniosacral therapy once weekly for six weeks, whereas the control group will receive the home exercise program only. Outcome measures will be assessed at baseline and after the six-week intervention period to compare the effectiveness of the two treatment approaches.

Gonarthrosis is a prevalent degenerative joint disease characterized by pain, joint stiffness, impaired physical function, and reduced quality of life. In addition to biomechanical impairments, individuals with gonarthrosis often experience alterations in autonomic nervous system activity, psychosocial factors such as kinesiophobia and body image disturbances, and limitations in functional mobility. While therapeutic exercise is considered a cornerstone of conservative management, complementary manual therapy approaches may provide additional benefits by targeting pain modulation and neurophysiological regulation.

Craniosacral therapy is a gentle manual therapy approach that aims to influence the craniosacral system and may contribute to pain reduction and autonomic regulation. However, evidence regarding its effectiveness as an adjunct to exercise-based rehabilitation in patients with gonarthrosis remains limited.

This randomized controlled trial was designed to investigate the effects of craniosacral therapy added to a standard home exercise program on pain, heart rate variability, joint stiffness, physical function, quality of life, body image, kinesiophobia, and dynamic balance in adult patients diagnosed with gonarthrosis. The primary objective is to determine whether the addition of craniosacral therapy to a home exercise program administered by physical therapists results in superior clinical outcomes compared with a home exercise program alone.

Eligible participants will be randomly allocated into two parallel groups. Both groups will perform a standardized home exercise program for a duration of six weeks. Participants in the experimental group will additionally receive craniosacral therapy once weekly for six weeks, whereas participants in the control group will receive the home exercise program only. All outcome assessments will be conducted at baseline and after the six-week intervention period by a physiotherapist blinded to group allocation.

The home exercise program will be prescribed and monitored by physiotherapists and will include exercises targeting knee joint mobility, muscle strength, flexibility, and functional performance. Craniosacral therapy sessions will be delivered by a trained physiotherapist following standardized clinical principles. Adherence to the exercise program will be monitored throughout the intervention period.

Outcome measures will include pain intensity, heart rate variability parameters, joint stiffness, physical function, quality of life, self-efficacy, kinesiophobia, body image perception, and functional mobility. The findings of this study are expected to contribute to the understanding of the potential role of craniosacral therapy as an adjunct to exercise-based rehabilitation in the management of gonarthrosis.

Inclusion Criteria:

• Age between forty and eighty-five years
• Diagnosis of knee osteoarthritis
• Ability to understand the study procedures and provision of written informed consent

Exclusion Criteria:

• Consumption of caffeine within the last four hours or use of tobacco within the last forty-eight hours prior to assessment
• Use of alcohol or recreational drugs within the last week
• Eating within two hours before the assessment
• History of neuropathic disorders
• History of unexplained syncope episodes
• Inability to move independently
• Presence of uncontrolled medical conditions, such as cardiac (e.g., angina) or respiratory (e.g., asthma) diseases
• Presence of neurological disorders, including Parkinson's disease or multiple sclerosis
• History of vascular surgery or open knee surgery, or receipt of a knee injection within the last one month
• Presence of somatic dysfunction symptoms or musculoskeletal injuries that may interfere with assessments
• Diagnosis of pregnancy, sarcopenia, cognitive impairment, or osteoporosis
• Any medical condition affecting the autonomic nervous system or immune system, including autonomic neuropathy, pure autonomic failure, autoimmune diseases, or acquired immunodeficiency syndrome