The conventional physical therapy group will receive Transcutaneous Electrical Nerve Stimulation (TENS) and hot pack application.

The stabilization group will receive lumbar stabilization exercises and the conventional physical therapy program. That program includes lumbar stabilization exercises including activation of the transverses abdominals (TA) and multifidi muscles.

The breathing exercise group will receive breathing exercises including sleep hygiene, and the stabilization group program. Breathing exercises include diaphragmatic breathing and pursed-lip.

Hot packs or hot water bags are superficial warming agents that will be used to heat muscle tissue, reduce muscle spasms and pain sensation. TENS is a pain reliever application.

Visual Analogue Scale will be used where patients will be asked to rate their pain on a scale from 0 to 10 with 0 indicating no pain and 10 the maximum worst pain, at the baseline and the end of 3 weeks intervention and at the end 8 weeks from baseline.

Form of Pain will be assessed with the Mcgill Melzack Pain Questionnaire. The questionnaire consists of four parts. In the first part, the individual marks the place where they feel pain on a representative body picture and indicates with the letters "D" if the pain is deep, "S" if it is on the body surface, and "D-S" if it is both deep and superficial. In the second part, there are 20 statements that examine pain from various aspects. The individual is asked to choose the word group that fits their pain and to marks only one word in the selected group that fits their pain. In the third part, there are questions about the relationship between time and pain. In the fourth part, five word-groups ranging from "mild to unbearable" pain are defined to determine the severity of pain.

Sleep quality will be assessed with the Pittsburgh Sleep Quality Index (PSQI). PSQI is a 19-item self-report questionnaire that measures subjective sleep quality over the previous month. The individual 19 items in the PSQI are aggregated into seven components that assess various aspects of sleep, and the sum of these seven components yields a score that distinguishes between "good" and "bad" sleepers.

Anxiety will be assessed with the Spielberger State-Trait Anxiety Inventory. It consists of two separate scales, each with 20 questions, assessing the levels of state anxiety and trait anxiety. The score that can be obtained from both scales is a minimum of 20 and a maximum of 80. If the score from the scale is high, the person's anxiety is high.

Stop-Bang Survey, used as a screening tool for obstructive sleep apnea (OSAS), is a questionnaire consisting of 8-item yes/no responses with a score for each positive answer.

Moderate risk of OSAS: yes to 3-4 questions, and high risk of OSAS: yes to 5-8 questions.