Relationship of Serum Magnesium and Vitamin D Levels to Range of motion and 30-Second Sit To Stand Test of Knee Osteoarthritis Patients

Osteoarthritis (OA) of the knee is a common degenerative joint disease and a major cause of disability, where limited range of motion (ROM) is one of the symptoms that impact the ability to perform daily activities and decrease physical performance. Assessment of the severity of knee OA is currently generally done by radiography, so it is important to detect modifiable risk factors, including micronutrients and assessment of ROM and physical performance with easy-to-do methods. Several studies have show that magnesium (Mg) and vitamin D play an important role in the development of joints, bones and muscles. This study aims to determine the effect of serum Mg and vitamin D levels on range of motion (ROM) and the 30-second sit to stand (30STS) test. This study was an observational analytic study with a cross-sectional design involving 44 patients with primary knee OA. Magnesium and vitamin D levels were measured and then compared with ROM and 30STS assessments using the Mann-Whitney test. The average Mg level was found to be within normal limits (1.91 mmol/L), while vitamin D levels were in the insufficient category (17.56 ng/mL). The results of the analysis showed that Mg levels did not show significant differences to ROM (p> 0.05) and 30STS (p> 0.05) while vitamin D levels showed significant differences to ROM (p<0.05) and 30STS (p<0.05). There was a significant relationship between serum vitamin D levels to ROM and 30STS, however, no significant relationship was found between Mg levels and both parameters in knee OA patients.