The Effect of Proprioceptive Neuromuscular Facilitation and Tendon Vibration After Total Knee Arthroplasty

Knee osteoarthritis is a degenerative joint disease characterized by the destruction and progressive loss of articular cartilage. In an advanced stage of the disease, the patient undergoes a total knee joint replacement with an artificial joint (total arthroplasty). The aim of this clinical study is to investigate the effect of combining a therapeutic exercise program based on Proprioceptive Neuromuscular Facilitation (PNF) and tendon vibration in older adult patients after total knee arthroplasty (TKA). Ninety (90) adults over 65 years of age who will undergo TKA due to knee osteoarthritis will be divided into three groups of 30 people each (two intervention and one control). The participants in the first group will follow a therapeutic exercise protocol based on the PNF technique for six weeks. The participants in the second intervention group will follow the same therapeutic exercise program based on PNF, and at the same time, tendon vibration will be applied on the common insertion tendon of the rectus femoris and vastus medialis for the same period. Finally, the participants in the third group (control group) will receive instructions for performing exercises at home via a leaflet without receiving any additional treatment. The subjective perception of pain with the Numeric Pain Rating Scale (NPRS), active range of motion (AROM) of knee flexion with a goniometer, functional ability with the Knee Injury and Osteoarthritis Outcome Score (KOOS), quality of life with the Western Ontario and McMaster Universities Arthritis Index (WOMAC), balance using the Timed Up and Go (TUG) test and Berg Balance Scale (BBS), center of mass displacement with a force platform, and knee proprioception through the calculation of joint position sense using the joint repositioning test will be assessed at the beginning of the intervention (4 weeks post-surgery), at the 6th week, and six months post-intervention. For the statistical analysis of the results, a two-factor analysis of variance with repeated measurements will be applied, with the statistical significance level set at p \< .05.

Background: Knee osteoarthritis is a degenerative joint disease characterized by destruction and progressive loss of articular cartilage. It occurs more often in older adults and is accompanied by pain, stiffness and swelling of the knee joint, difficulty in walking, and a decrease in the functioning of the patient. In an advanced stage of the disease, the patient undergoes a total replacement of the knee joint with an artificial joint (total arthroplasty).

Aim: The aim of this clinical study is to investigate the effect of combining a therapeutic exercise program based on Proprioceptive Neuromuscular Facilitation (PNF) and tendon vibration in older adult patients after total knee arthroplasty (TKA).

Method: Ninety (90) adults over 65 years of age who will undergo TKA due to knee osteoarthritis will be divided into three groups of 30 people each (two intervention and one control). The participants in the first group will follow a therapeutic exercise protocol based on the PNF technique for six weeks. The participants in the second intervention group will follow the same therapeutic exercise program based on PNF, and at the same time, tendon vibration will be applied on the common insertion tendon of the rectus femoris and vastus medialis for the same period. Finally, the participants in the third group (control group) will receive instructions for performing exercises at home via a leaflet without receiving any additional treatment. The subjective perception of pain with the Numeric Pain Rating Scale (NPRS), active range of motion (AROM) of knee flexion with a goniometer, functional ability with the Knee Injury and Osteoarthritis Outcome Score (KOOS), quality of life with the Western Ontario and McMaster Universities Arthritis Index (WOMAC), balance using the Timed Up and Go (TUG) test and Berg Balance Scale (BBS), center of mass displacement with a force platform, and knee proprioception through the calculation of joint position sense using the joint repositioning test will be assessed at the beginning of the intervention (4 weeks post-surgery), at the 6th week, and six months post-intervention. For the statistical analysis of the results, a two-factor analysis of variance with repeated measurements will be applied, with the statistical significance level set at p \< .05.

Expected results: It is known that older adults with TKA present deficits in balance and knee proprioception due to the long-term functional limitations caused by the symptoms of the disease (difficulty and pain during standing and movement, impaired gait patterns). These deficits persist even after TKA, making older adults more vulnerable to falls and future injuries. Both PNF and tendon vibration are effective therapeutic approaches for proprioception training in older adults. The investigators believe that the inclusion of tendon vibration in the PNF-based therapeutic exercise program will further increase the balance and proprioceptive ability of older adults, while at the same time accelerating their recovery process. Additionally, the effectiveness of an exercise program based on PNF has not been sufficiently studied.

Eligibility Criteria:
Inclusion Criteria:

* Age over 65 years
* Unilateral primary total knee arthroplasty
* Body mass index less than 30
* Active knee flexion range of motion of at least 90° two weeks after surgery
* Written consent to participate in the research

Exclusion Criteria:

* Non-ambulatory patients with knee osteoarthritis
* Infections and other surgical complications following the procedure that result in prolonged hospitalization
* Neurodegenerative disease (e.g., Parkinson's)
* Cognitive deficits - dementia (Mini Mental State Exam Test score \< 23)