Pain free passive knee extension test (PKET)

This test belongs to the ASPETAR hamstring test battery (Aspetar Hamstring Protocol). It is used to assess the passive knee extension range of motion (ROM) and the degree of shortening of the hamstring muscle group.

• Required material: A physiotherapy couch. If the test is performed on the floor, a mat is required. It is advisable to measure the ROM angle with an inclinometer.

• Procedure: The subject lies supine (face up) with the hip and knee in 90° flexion (Illustration A). The assessor should fix the limb being assessed and gradually extend the knee to the point where there is a restriction due to shortening of the muscle group. The test should end if pain is manifested or pelvic retroversion is initiated.

• Assessment: Bearing in mind that maximum knee extension indicates the 0 degree of joint reference (Illustration B). Values between 0°-15° are considered normal ranges, moderate ranges between 16°-34° and values greater than or equal to 35° as ranges of limitation, which could indicate injury risk.