Influence of water exercise and land stretching on salivary cortisol concentrations and anxiety in chronic low back pain patients.

Land stretching exercises are common exercise therapy for low back pain (LBP) patients. However, recently, water exercise became a popular rehabilitation for LBP patients, and many studies have reported the physical benefits of water exercise. This study compared the psychological and endocrinological effects of water exercise and land stretching by measuring salivary cortisol concentration and anxiety in chronic LBP patients. Seven volunteers (4 female and 3 male, mean age: 61.9 +/- 11.8 yrs) who suffered from chronic LBP (pain duration: 4.5 +/- 1.3 yrs) participated in the sessions of water exercise and land stretching programs (90 minutes) on different days. The land stretching program consisted mainly of stretching, and the water exercise program contained not only stretching, but also walking, jogging, muscle strengthening, swimming and relaxation. After both exercise programs, the subjective pain scores of the patients showed a significant decrease. Salivary cortisol concentrations were also significantly decreased during pre- to post-90 minute water exercise. (P < 0.05). With land stretching, salivary cortisol concentrations also decreased significantly (P < 0.05). State anxiety decreased significantly (P < 0.05) after both water exercise and land stretching compared with pre-exercise scores (P < 0.05), though no significant changes were found in the patients' trait anxiety scores. No significant correlation was found between salivary cortisol concentrations and state anxiety with water exercise and land stretching. The findings of the present study suggested both exercises showed similar tendencies, and had decreased salivary cortisol level and state anxiety.