Which statement describes the typical hop-test finding after ACL injury?

• A. Increased performance on hop tests
• B. No change in hop performance
• C. Painful ambulation only
• D. Decreased performance on hop tests (6m single limb timed hop test <80%)

Answer: (D)

After ACL injury, functional knee performance typically drops because of weakness, especially quadriceps inhibition, plus altered neuromuscular control and fear of giving way. When you test function with hops, the injured leg usually cannot match the uninjured leg. In a 6-meter single-leg timed hop, this shows up as a longer time (slower performance) on the injured side, often with a limb symmetry index under about 80%. So the common finding is decreased hop performance on the injured knee, reflecting the deficit in strength, power, and control needed for explosive single-leg movements. The other options don’t fit the usual pattern: performance isn’t typically better, and while pain can be present, the hallmark is reduced, asymmetric performance.