In Kendall test protocol, which elements determine whether hip or knee extension occurs first?

In Kendall test protocol, which elements determine whether hip or knee extension occurs first?

• A. The pelvis is stabilized, while the knee is extended passively and the thigh position is observed.
• B. Pelvic tilt is controlled, thigh position relative to the table is observed, and knee angle is assessed to determine whether hip or knee extension occurs first.
• C. The patient performs trunk flexion to gauge hip extension.
• D. Ankle dorsiflexion is measured to determine hip extension.

Answer: (B)

The test is designed to determine the order of movement between the hip and the knee when extending the leg, so you need to control for any compensations and directly observe which joint initiates the motion. First, pelvis stability is crucial. If the pelvis moves or tilts, it can masquerade as hip movement or hide the true knee contribution. By keeping the pelvis fixed, you ensure that any observed motion comes from the hip or knee joints themselves, not from surrounding structures. Second, watching the thigh’s position relative to the table shows how the leg moves as extension occurs. If the thigh rises and the knee remains relatively still, hip extension is occurring first. If the knee extends while the thigh remains in a similar position, knee extension is happening first. This visual cue helps identify the sequence of joint involvement. Third, measuring the knee angle provides objective confirmation of that sequence. By noting whether the knee extends before the hip moves or after, you can determine which joint initiates the extension. The other approaches don’t align with this purpose: trunk flexion doesn’t reliably indicate hip versus knee initiation, and assessing ankle dorsiflexion or omitting pelvis control misses the key factors that reveal the true order of joint extension.

The test is designed to determine the order of movement between the hip and the knee when extending the leg, so you need to control for any compensations and directly observe which joint initiates the motion.

First, pelvis stability is crucial. If the pelvis moves or tilts, it can masquerade as hip movement or hide the true knee contribution. By keeping the pelvis fixed, you ensure that any observed motion comes from the hip or knee joints themselves, not from surrounding structures.

Second, watching the thigh’s position relative to the table shows how the leg moves as extension occurs. If the thigh rises and the knee remains relatively still, hip extension is occurring first. If the knee extends while the thigh remains in a similar position, knee extension is happening first. This visual cue helps identify the sequence of joint involvement.

Third, measuring the knee angle provides objective confirmation of that sequence. By noting whether the knee extends before the hip moves or after, you can determine which joint initiates the extension.

The other approaches don’t align with this purpose: trunk flexion doesn’t reliably indicate hip versus knee initiation, and assessing ankle dorsiflexion or omitting pelvis control misses the key factors that reveal the true order of joint extension.