Study design: This study will be randomizaed controlled trail.1. Participants:forty-two patients with chronic mechanical low back pain. age:20-45. Th sample size population: was calculated using the G*power program 3.1.9 (G power program version 3.1, Heinrich-Heine-University, Düsseldorf, Germany) for one tailed test. Sample size calculation based on F tests (ANOVA: Special effects and interactions), Type I error (a) = 0.05, power (1-ß error probability) = 0.80, Pillai V = 0.3300000 and effect size f (V) = 0.8 with 2 independent groups comparison for 3 major variable outcomes. The appropriate minimum sample size for this study was 42 patients (21 patients in each group). Procedure:First, the purpose of the study will be explained to the patients and the procedures are fully explained. Then, patients will be asked to participate in the study. If they accepted, an informed consent form will be signed and randomly assigned in one of two groups (by closed envelope method). All subjects will be evaluated for their pain intensity,lumbar spine mobility and functional disability level. All patients will be tested before and after the treatment program (12 treatment sessions, 3 sessions per week for 4 weeks). Each patient will receive exercises (stretching and strengthening exercises) for the control group (A), the stretching exercises include (Hamstring stretching- Lower back stretching) and the strengthening exercises- include (Abdominal curl up- Supine bridging-Trunk extension). For the experimental group (B), they will receive exercises (stretching and strengthening exercises) then the thoracic lymphatic pump technique.
The purpose of the study is to compare between the combined effect of thoracic lymphatic pump technique with exercises and exercises alone on pain intensity using Visual Analogue Scale (VAS), lumbar spine mobility using Modified-Modified Schober test (MMST) and functional disability level using Oswestary Disability Index (ODI) on patients with CMLBP.