A normal Craig's test means that a person has normal femoral anteversion, which is often measured between 8 degrees and 15 degrees of internal rotation in adults.
During the Craig's test, the person being tested, lays prone with their knee flexed to 90 degrees and the greater trochanter is found at it's most lateral position, which is parallel to the table, within this specific rotational range.
The key aspects of a normal Craig's test result includes.
The angle, which is 8 to 15 degrees of inward rotation.
Alignment, which is when the femoral head is centered properly within the hip socket also known as the acetabulum when the greater trochanter is at it's most prominent lateral point.
A result in this range is what indicates that the angle of the femoral neck is not causing any excessive twisting of the thigh bone, which also reduces the likelihood of gait issues such as significant in-toeing or squinting patellae which are when kneecaps point towards each other.
Abnormal findings on the Craig's test are increased Anteversion, which is when there's an angle of > 15 degrees, which suggests excessive internal rotation, which is often associated with in-toeing.
And retroversion, which is when there's an angle of < 8 degrees that suggests that the femur is rotated backwards.
The Craig's test is often used to identify structural factors in people that are experiencing hip pain or knee pain.
The Craig's test also has moderate to high inter-examiner reliability like (ICC 0.72–0.77), although it may not always correlate perfectly with CT scans.
The procedure of the Craig's test involves.
The patient, lies prone on their stomach, with their knee flexed to 90 degrees.
The doctor or clinician then palpates the greater trochanter on the side that is being tested.
The hip is then passively rotated internally and externally until the greater trochanter is at it's most lateral/prominent position.
And a goniometer is also used to measure the angle of the lower leg in relation to the vertical table line.
The Craig's test is useful for assessing for structural, instead of just functional issues with inward or outward turning of your legs.