Kinesiological / Dietary Supplement Intervention in Knee Osteoarthritis

WOMAC is a self-assessment questionnaire consisting of 24 questions, addressing pain, stiffness, and physical function in individuals with knee or hip osteoarthritis. A higher achieved value or sum of points (0-96) indicates a worse condition.

SF-36 is a self-assessment questionnaire on quality of life consisting of 36 items, which are grouped into domains measuring eight health components: physical functioning, role limitations due to physical health, role limitations due to emotional health, vitality, mental health, social functioning, bodily pain, and general health. Each item is scored, and each health component provides a score ranging from 0 to 100, where a score of 0 indicates very poor health, while a score of 100 indicates excellent health.

Numeric rating scale (NRS) measures pain intensity. It is subjectively assess the current level of knee pain on a scale from 0 (no pain) to 10 (worst possible pain). Change = week 12 score - baseline score

A timed walk of 4 x 10 metres for a total of 40 metres

A piezoelectric force plate (Kistler, Winterthur, Switzerland, model 9260AA) for a measure forces on the surface, allowing us to record the movement of the center of pressure on the surface over time. The position is a single-leg stance, with the test conducted with eyes open, and parallel stance with the test conducted with eyes open and eyes closed, with three 30-second repetitions in each position. In evaluating the quality of static balance performance, investigators will calculate time of single-leg stance and parallel stance.

The position is a single-leg stance and parallel stance on piezoelectric force plate (Kistler, Winterthur, Switzerland, model 9260AA) for a measure forces on the surface, with the test conducted with eyes open and eyes closed, with three 30-second repetitions in each position. In evaluating the quality of static balance performance, investigators will calculate overall and direction-specific amplitude from the center of pressure on the surface.

The position is a single-leg stance and parallel stance on piezoelectric force plate (Kistler, Winterthur, Switzerland, model 9260AA) for a measure forces on the surface, with the test conducted with eyes open and eyes closed, with three 30-second repetitions in each position. In evaluating the quality of static balance performance, investigators will calculate overall and direction-specific velocity from the center of pressure on the surface.

The position is a single-leg stance and parallel stance on piezoelectric force plate (Kistler, Winterthur, Switzerland, model 9260AA) for a measure forces on the surface, with the test conducted with eyes open and eyes closed, with three 30-second repetitions in each position. In evaluating the quality of static balance performance, investigators will calculate overall and direction-specific frequency from the center of pressure on the surface.

Chair Stand Test is measure lower body strength, in which participants stand up repeatedly from a chair for 30 seconds with their arms across their chest. Investigators will measure the number of repetitions in one set.

The Five Times Sit to Stand Test scoring is based on the amount of time (to the nearest decimal in seconds) a participant is able to transfer from a seated to a standing position and back to sitting five times with their arms across their chest. Test is used to asses functional lower limbs strength, balance, and fall risk.

The participant sits on the edge of a chair. One foot must remain flat on the floor, while the other leg is extended forward with the knee straight, heel on the floor, and ankle bent at a 90° angle. One hand is placed on top of the other, with the middle fingers aligned. The participant reaches forward towards the toes by bending at the hips. The back remains straight. The final position is held for 2 seconds. Investigators measure the distance between the fingertips and the toes. Two trials are performed, and the better result is considered.

Timed up-and-go test measures functional mobility and balance. Participants will start seated in a chair with armrests. Upon the investigator's signal, participants will rise from the chair, walk 3 meters forward, turn around, walk back to the chair, and sit down. The time taken to complete the task will be recorded to the nearest tenth of a second. The test will be performed three times, and the best time will be recorded for analysis.

After the practice trial, participants will perform one test trial, during which they will be instructed to ascend and descend a flight of 10 stairs as quickly as possible while maintaining safety. The time taken to complete the task will be recorded to the nearest tenth of a second.

6-Minute Walk Test is a sub-maximal exercise test used to assess aerobic capacity and endurance. The distance covered over a time of 6 minutes is used as the outcome.

Maximal isometric voluntary contraction of knee flexion and extension will be performed using a knee dynamometer (S2P, Science in Practice, Ltd., Ljubljana, Slovenia), which will allow knee flexion and extension under static conditions with a knee joint angle of 60° and hip flexion in a seated position at 90°. A support will be placed over the ankle (2-3 cm above the lateral malleolus), through which the participant will press against the measuring part of the device. Before the measurement, the participant will perform two repetitions of flexion and extension with submaximal force, aimed at warming up the participant and familiarizing them with the test requirements. This will be followed by 3 muscle contractions with a 3-second hold at the maximum force produced, during which the participant will be verbally encouraged to achieve maximum strength.

Blood sample analysis for the presence of inflammatory markers (CRP, TNF-α, IL-6, IL-1β)

Assess 24-hour time use with activPAL sensors (sleep, wakefulness, sedentary behavior, physical activity).

DAB-Q questionnaire for recalling a seven-day period of time use. It assesses the time spent sleeping, awake/sedentary, and engaging in physical activity within the context of 24-hour time use.

Handgrip strength will be measured using a hand hydraulic dynamometer. Participants will sit with their elbow flexed at 90° and squeeze the device handle as hard as possible for three seconds. Three repeated measurements will be taken from the dominant hand, and the maximum value (in kilograms) will be recorded.

An arm curl test assess upper body strength. The test involves sitting in a chair holding a weight with the palm facing the body. The arm should be against the trunk to avoid using other muscle groups. As the arm is brought through the range of motion, the wrist should rotate ending up facing the participant (supination). The number of repetitions (as many curls) in 30 seconds is used as the outcome.

The Back Scratch Test measures how close the hands can be brought together behind the back. This test is done in the standing position. Investigators measure the distance between the tips of the middle fingers. Two trials are performed, and the better result is considered.