How to measure hip range of motion

Clinical guide · Reviewed by Kevin Lan, OTR/L, ATP · Updated July 2026

To measure hip flexion with a goniometer, position the patient supine, center the fulcrum over the greater trochanter, align the stationary arm with the lateral midline of the trunk and the moving arm with the lateral midline of the femur toward the lateral epicondyle, then bring the thigh toward the chest and read the angle. Normal hip ROM is about 120° flexion, 45° abduction, and 45° external rotation (AAOS). The steps, landmarks, and reliability evidence are below.

Normal hip range of motion

See the full normal range of motion chart for every joint. The Goniometer app guides hip flexion, extension, abduction, adduction, and internal and external rotation with animated placement.

What you need

• A universal goniometer, digital goniometer, or a smartphone goniometer app.
• A firm surface where the patient can lie supine with the leg free to move.
• Reference to the landmarks: the greater trochanter, the lateral midline of the femur (toward the lateral epicondyle), and the lateral midline of the trunk.

How to measure hip flexion, step by step

1. Position the patient. Supine with the legs extended and relaxed — this is the 0° starting position.
2. Find the landmarks. Locate the greater trochanter, the lateral midline of the femur toward the lateral epicondyle, and the lateral midline of the trunk.
3. Center the fulcrum. Place the goniometer axis over the greater trochanter.
4. Align the arms. Line the stationary arm along the lateral trunk and the moving arm along the lateral midline of the femur.
5. Move to end range. Bring the thigh toward the chest until it stops, allowing the knee to bend, and keep the arms tracking the landmarks.
6. Read and record. Read the angle at end range and note the side (L/R) and patient position.

Hip extension

Position the patient prone with the legs flat, then lift the thigh backward off the table, keeping the knee straight and stabilizing the pelvis to avoid lumbar compensation. Normal extension is about 30°. In the app the phone lies along the femur and reads 0° automatically with the leg flat; a side-lying start is also supported.

Hip abduction

Keep the patient supine with the legs straight and slide the leg out to the side, away from the midline, with the kneecap pointing up. Normal abduction is about 45°. Set the phone to zero with the legs together, then read at end range.

Hip adduction

From the same supine start, bring the leg across the midline, over or under the opposite leg. Normal adduction is about 30°. Zero the phone with the legs together and read at end range.

Hip external rotation

Flex the hip and knee to 90° and rotate the hip so the foot swings toward the midline; normal is about 45°. In the app this uses the phone’s attitude reference with the shin as the pointer.

Hip internal rotation

From the same 90°/90° position, swing the shin the opposite way so the foot moves outward, away from the midline. Normal internal rotation is about 45°. As with external rotation, the app reads true rotation with the shin as the pointer.

Getting a reliable measurement

Manual hip goniometry is most reliable when the same examiner measures the same way each time. Nussbaumer and colleagues found manual goniometers valid and reliable for passive hip range of motion on a test-retest (intra-rater) basis when compared against an electromagnetic tracking system. Four habits keep readings repeatable:

• Standardize the position. Measure supine, and stabilize the pelvis so it does not tilt or rotate to add apparent motion.
• Palpate the landmarks each time rather than eyeballing them — landmarking is the biggest source of variation.
• Read at a stable end range, not mid-motion, and to the whole degree.
• Use one examiner for progress tracking. Compare a patient’s hip to their own earlier measurement, taken the same way.

Measuring hip ROM with an iPhone

A smartphone goniometer app replaces the two-armed goniometer with the phone’s gravity-referenced motion sensor: lay the phone along the thigh, set zero, and the change in tilt as the hip flexes is the joint angle. Peer-reviewed research finds smartphone measurement valid and reliable for hip ROM, comparable to a universal goniometer — see the accuracy evidence. A 2022 study reported high intra-rater reliability (ICC above 0.72) for smartphone hip goniometry, again strongest with a single examiner (Takeda & Furukawa).

Frequently asked questions

References

• Norkin CC, White DJ. Measurement of Joint Motion: A Guide to Goniometry. 5th ed. Philadelphia: F.A. Davis; 2016.
• American Academy of Orthopaedic Surgeons. Joint Motion: Method of Measuring and Recording. Chicago: AAOS. Normative range-of-motion reference values, as used throughout the Goniometer app.
• Nussbaumer S, Leunig M, Glatthorn JF, et al. Validity and test-retest reliability of manual goniometers for measuring passive hip range of motion in femoroacetabular impingement patients. BMC Musculoskeletal Disorders. 2010;11:194. doi:10.1186/1471-2474-11-194
• Takeda Y, Furukawa K. Clinical reliability and usability of smartphone goniometers for hip range of motion measurement. Journal of Physical Therapy Science. 2022;34(6):433–439. doi:10.1589/jpts.34.433
• Keogh JWL, Cox A, Anderson S, et al. Reliability and validity of clinically accessible smartphone applications to measure joint range of motion: A systematic review. PLOS ONE. 2019;14(5):e0215806. doi:10.1371/journal.pone.0215806

Related guides

Goniometer is an educational and reference tool. It is not a medical device and is not intended for diagnosis or treatment decisions.