and the spasm in the muscle arterioles. It exerts analgesic and anti-in ammatory e ects by promoting regeneration and increasing the release of beta-endorphins through the induction of protein synthesis in the rheumatoid synovial uid. Laser is also suggested to stimulate hematopoiesis in the bone marrow and exert antibacterial e ects by stimulating the immune system [4]. Lasers do not cause a signi cant change in the tissue temperature. is nding indicates that the potential physiological e ects of laser are independent from heat. Recent studies implicated laser in the regenerative process of the tissue, bone formation, synthesis of new carti- lage tissue, and synthesis of the cartilage matrix [5, 6]. It was found that Nd: YAG lasers contribute to the healing process in the tendons and ligaments and prevent the formation of brosis [7]. Some studies showed that low level laser therapy combined with exercise had more bene cial than exercise alone in chronic low-back pain for the long term [8–10].
Super cial and deep heaters used in the treatment of lumbar disc herniations have an important place in physical therapy applications. Super cial and deep heaters have mul- tiple e ects such as vasodilation, increased pain threshold, and increased collagen production in connective tissues. It was found that ultrasound (US) exerts many e ects mediated by its thermal e ects such as increase in nerve transmission speed and enzymatic activity, increase in the contractility of skeletal muscles, increase in the elongation of collagen tissue, increase in blood ow rate, decline in pain threshold, and relief of muscle spasms [11]. US is important physical therapy agent used in the treatment of musculoskeletal disorders [12].
e aim of the present study is to evaluate the e ciency of high intensity laser and ultrasound therapy in patients who are diagnosed with lumbar disc herniation and who are capable of performing physical exercises.