In the 90-90 straight leg raise test, what does a reduced knee extension indicate?

In the 90-90 straight leg raise test, what does a reduced knee extension indicate?

• A. Quadriceps tightness
• B. Hamstring tightness
• C. IT band tightness
• D. Patellar tendon pathology

Answer: (B)

The test is focused on hamstring flexibility when the hip is flexed to 90 degrees. In this position, the hamstrings are lengthened over the knee. If they are tight, they resist lengthening, so the knee cannot fully straighten. That’s why a reduced knee extension in the 90-90 straight leg raise points to hamstring tightness—the hamstrings cross both the hip and knee and limit knee extension when the hip is flexed. The other options don’t explain this specific mechanical limitation. Quadriceps tightness wouldn’t primarily block extending the knee in this hip-flexed position, and IT band tightness or patellar tendon pathology would show different pain patterns or functional signs rather than a pure limitation of knee extension due to hamstring length.

The test is focused on hamstring flexibility when the hip is flexed to 90 degrees. In this position, the hamstrings are lengthened over the knee. If they are tight, they resist lengthening, so the knee cannot fully straighten. That’s why a reduced knee extension in the 90-90 straight leg raise points to hamstring tightness—the hamstrings cross both the hip and knee and limit knee extension when the hip is flexed.

The other options don’t explain this specific mechanical limitation. Quadriceps tightness wouldn’t primarily block extending the knee in this hip-flexed position, and IT band tightness or patellar tendon pathology would show different pain patterns or functional signs rather than a pure limitation of knee extension due to hamstring length.