From the Guidelines
To elicit psoas and obturator signs, specific physical examination maneuvers must be performed, prioritizing patient comfort and accurate diagnosis, as supported by general medical knowledge and not directly addressed in the provided evidence 1.
Eliciting Psoas Sign
The psoas sign can be elicited by having the patient lie on their left side and passively extending their right hip by moving the right thigh backward while keeping the knee extended. Alternatively, the patient can lie supine and actively raise their right thigh against resistance provided by the examiner's hand. Pain with either maneuver indicates a positive psoas sign, suggesting irritation of the iliopsoas muscle, which can be further evaluated using imaging techniques such as MRI, as discussed in the context of hip pain evaluation 1.
Eliciting Obturator Sign
For the obturator sign, the patient should be positioned supine with their right hip flexed to 90 degrees and the knee bent. The hip is then rotated internally and externally. Pain with this movement, particularly on internal rotation, constitutes a positive obturator sign, indicating irritation of the obturator internus muscle. While the provided evidence focuses on chronic hip pain and the use of imaging modalities like MRI and US for diagnosis 1, these physical examination signs are crucial for diagnosing conditions that may cause similar symptoms.
Importance of Clinical Context
It's essential to interpret these signs alongside other clinical findings, laboratory results, and imaging studies for an accurate diagnosis, considering the complexities of hip and abdominal pathology. The use of MRI, as highlighted in the evidence 1, can be critical in evaluating soft tissue abnormalities and osseous structures, aiding in the diagnosis of conditions that may present with similar symptoms to those indicated by positive psoas and obturator signs.
From the Research
Eliciting Psoas and Obturator Signs
To elicit psoas and obturator signs, the following methods can be considered:
- The psoas muscle is innervated by the ipsilateral lumbar spinal nerve roots (L2-L4) 2, which can be stimulated to relieve pain.
- Disorders of the iliopsoas can cause groin pain, and treatment options include activity modification, physical therapy, nonsteroidal anti-inflammatory drugs, and corticosteroid injections 3.
- The obturator nerve descends posterior to the psoas major muscle, and understanding this anatomy is important for avoiding iatrogenic injuries during surgical approaches 4.
- Nonsteroidal anti-inflammatory drugs can be used to treat musculoskeletal pain, including osteoarthritis, trauma, overuse syndromes, and compression fractures 5.
- NSAID injections may be an alternative to steroid injections for musculoskeletal pain, with some studies showing equivalent or better pain relief and a lower recurrence rate of symptoms 6.
Clinical Applications
The relationship between the obturator nerve and psoas major muscle is important for clinicians to understand, particularly when interpreting radiology or treating patients with presumed obturator compression syndromes 4. The use of nonsteroidal anti-inflammatory drugs and corticosteroid injections should be carefully considered, taking into account the potential side effects and benefits of each treatment option 3, 5, 6. Peripheral nerve stimulation of the psoas muscle may be a viable treatment option for patients with psoas muscle pain, as shown in a case study where a patient experienced over 50% improvement in pain scores after undergoing temporary peripheral nerve stimulation 2.