During Ober's test, what does a greater drop with the knee flexed indicate?

During Ober's test, what does a greater drop with the knee flexed indicate?

• A. Rectus femoris contribution.
• B. ITB tightness only.
• C. Piriformis involvement.
• D. Gluteus maximus weakness.

Answer: (A)

The key idea is that changing the knee position during Ober’s test helps tell whether the limitation comes from the rectus femoris in addition to the IT band. When the knee is kept straight, the rectus femoris crosses both the hip and knee and is stretched across the hip, adding to the tension that can keep the leg from dropping. If you bend the knee, the rectus femoris becomes slack, so its influence on restriction decreases. If you observe a greater drop of the leg with the knee flexed, it shows that the rectus femoris was contributing to the restriction when the knee was extended. In other words, the test is identifying rectus femoris involvement rather than IT band tightness alone. The other options don’t fit because IT band tightness alone would not explain a bigger drop when the knee is flexed, and piriformis involvement orgluteus maximus weakness aren’t what Ober’s test differentiates.

The key idea is that changing the knee position during Ober’s test helps tell whether the limitation comes from the rectus femoris in addition to the IT band. When the knee is kept straight, the rectus femoris crosses both the hip and knee and is stretched across the hip, adding to the tension that can keep the leg from dropping. If you bend the knee, the rectus femoris becomes slack, so its influence on restriction decreases. If you observe a greater drop of the leg with the knee flexed, it shows that the rectus femoris was contributing to the restriction when the knee was extended. In other words, the test is identifying rectus femoris involvement rather than IT band tightness alone. The other options don’t fit because IT band tightness alone would not explain a bigger drop when the knee is flexed, and piriformis involvement orgluteus maximus weakness aren’t what Ober’s test differentiates.