This is a case report about a female fell down from a chair and suffered right lumbago and buttock pain for days. Besides soft tissue contusions, the patient described in this case report would diagnosed as having sacroiliac joint rotation dysfunction based on the absence of any abnormal radiological findings. It is important for clinicians that rather than relying on one test, classification of a iliac dysfunction should be based on information of the history taking examination and a 'cluster of tests' in combination with a reasoning process. Furthermore, the choice of treatments should based on the diagnosis and dysfunction classification assigned to the patient. We'd like to introduce the evaluation methods about iliac dysfunction similar to this case and discuss the inserting depth of each selected muscle.