Phelps Test

Discover the Phelps Test for assessing gracilis muscle contractures. Use our template for accurate diagnosis and effective treatment planning.

By Nate Lacson on Aug 2, 2025.

Fact Checked by Ericka Pingol.

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What is the gracilis muscle?

The gracilis muscle is a long, slender muscle located in the thigh's medial (inner) part. It is part of the adductor group and is unique because it is biarticular, which crosses both the hip and knee joints.

The gracilis muscle supports several key functions: hip flexion, knee flexion, internal rotation, and adduction of the leg. These movements are critical for smooth lower limb mobility. Specifically, it assists with flexing the hip and knee during walking or climbing stairs, standing on one leg, rotating the thigh inward, and pulling the legs toward the body’s midline for balance and stability.

Below are common problems associated with a tight gracilis muscle:

Limited hip flexion and knee extension
Restricted internal and external rotation of the hip
Pelvic obliquity, leading to postural misalignment
Altered muscle function contributing to abnormal lumbar lordosis
Impact on hip, knee, and ankle movements, affecting gait and daily activities

Phelps Test Template

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What is the Phelps Test?

The Phelps Test is a diagnostic procedure used to assess the length of the gracilis muscle and identify contractures or shortening of this muscle. It helps detect abnormalities related to hip flexion and gracilis contractures. Here's how to perform the Phelps Test:

The patient is positioned in a prone position with extended knees on an examination table.
The examiner passively abducts the patient's legs as far as possible while keeping the knees extended.
The patient is then asked to flex their knees to 90°.
The examiner attempts to passively abduct the hips with flexed knees.

The angle formed between the horizontal axis of the thigh and a horizontal line parallel to the floor is measured to assess hip flexion contracture. This test can also be done in a supine position to assess other aspects of the gracilis muscle and determine overall impairment.

Interpreting the results of the Phelps Test

The outcomes of this test provide insights into the functionality and limitations of the gracilis muscle, which guides assessment and subsequent medical interventions. Here's how to interpret the results of the Phelps Test:

Positive test: If the hip abduction range increases after the knees are flexed to 90°, this indicates potential contractures in the gracilis muscle. Knee flexion shortens the gracilis muscle, allowing more hip abduction if the gracilis is the limiting factor.
Negative test: If there is no significant increase in hip abduction when it is repeated with the knee flexed, this suggests that the gracilis muscle is not the limiting factor.

After interpreting the results, the next steps typically include developing a targeted treatment plan to address any limitations found. This may involve physical therapy, stretching routines, or other interventions to improve hip mobility. Follow-up assessments help track progress and ensure the treatment plan is achieving the desired outcomes.

How to use our Phelp's Test template

Our Phelps Test template is a helpful tool for assessing and testing the length of the gracilis muscle and identifying potential contractures. Here's how you can integrate it into your practice.

Step 1: Access the template

Click the "Use template" button to open the Phelps Test template directly in our app. Here, you can fill out the details, customize fields, and save them to your records. Alternatively, click the "Download" button to get a fillable PDF that you can print or use on your device

Step 2: Position the patient and conduct the test

Follow the provided steps to position the patient correctly according to the template instructions. Proper positioning is crucial for the accuracy and outcome of the test. The greater trochanter of the femur is used as a reference point during the test to measure specific pathologies. Perform the Phelps Test based on the indicated procedure.

Step 3: Record and interpret the test results

Document the results by ticking the appropriate checkbox to indicate whether the test is positive or negative for gracilis contracture. Use the provided guide to interpret the results: an increase in the hip abduction angle after knee flexion indicates a positive result for gracilis contracture, while no significant change indicates a negative result.

By following these steps and documenting the results correctly, you can effectively diagnose and plan interventions for issues related to the gracilis muscle using the Phelps Test template.

Benefits of conducting this test

This test is a valuable diagnostic tool, as it can help assess and manage gracilis muscle contractures. Incorporating the test into routine examinations can enhance patient care and effectively address musculoskeletal challenges.

The Phelps Test allows for precise measurement of hip abduction angles when the knee is flexed to 90 degrees, which helps to detect muscle contractures and deformities accurately.
It is beneficial for children and school health programs, aiding in the early detection of developmental challenges and trauma-related issues and ensuring timely interventions.
Identifying affected areas and understanding the severity of contractures can help develop targeted treatment plans and improve outcomes for patients facing musculoskeletal problems.
The test supports broader public health initiatives by providing critical data for community health programs and enhances overall community interest in musculoskeletal health.
Regular use of the test in examinations ensures every aspect of the patient's condition is measured and managed effectively, leading to greater patient care and functional mobility achievement.

Commonly asked questions

To test for adductor tightness, use the Thomas test or Phelps Test. The patient lies supine on an examination table, and the practitioner moves the legs outward to assess hip abduction. Tightness in the adductor muscles restricts this range of motion, indicating limited flexibility or muscle contracture.

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The Phelps Test is a reliable way to assess the gracilis muscle. It involves positioning the patient prone and abducting the legs with extended and flexed knees. An increased abduction range after knee flexion indicates gracilis contracture. This muscle’s involvement in hip adduction and knee flexion makes this test particularly useful.

The Phelps Test assesses hip abduction contractures by measuring the change in hip abduction with the knee flexed to 90 degrees. If hip abduction improves with knee flexion, it suggests the gracilis muscle causes the contracture. This test helps identify muscle imbalances and informs the development of treatment plans.