Background: There is no proven relationship between back pain and trunk muscle strength, researches in this field yielded conflicting results: some found significant weakness of trunk muscles in back pain patients compared with healthy subjects, however many researches did not show any relation- ship.
Objectives: The focus of this study is to assess the trunk muscles strength using isokinetic dynamometer then tries to find a relation between back pain and trunk muscles strength.
Materials and Methods: Fifty patients with back pain (BP) and 50 healthy subjects were recruited in this study. The flexors and extensors of the trunk muscles were evaluated by Isokinetic dy- namometer and compared with control groups.
Results: Patients with acute back pain show a significant reduction of the trunk muscles strengths at 120 ̊/s velocities (p value < 0.05) with reversed flexor/extensor ration in comparison with sound subjects. Such a relationship does not show in subacute or chronic back pain patients.
Conclusions: Acute back pain associ- ated with decreased the strength of the trunk flexors and extensors at 120 ̊/s. The trunk muscle reinforcement programs must be considered in-patients with acute back pain.