What is the MDC for the single limb crossover hop for distance?

What is the MDC for the single limb crossover hop for distance?

• A. 40.00 cm
• B. 44.00 cm
• C. 48.75 cm
• D. 49.17 cm

Answer: (D)

Minimal detectable change is the smallest amount of change that exceeds the expected measurement error for a test, with a chosen level of confidence (often 95%). It’s derived from the test’s reliability and variability: MDC at 95% confidence is calculated from the standard error of measurement (SEM), which themselves come from the test’s standard deviation and reliability (ICC). In practice, MDC tells you how much a patient’s score must change before you can be confident that the change reflects a real difference rather than noise or measurement error. For the single limb crossover hop for distance, the MDC95 value reported in the relevant data is 49.17 cm. This means that, for an individual, an improvement or decline of about 49 cm or more is required before you can say with 95% confidence that there is a true change in performance. Changes smaller than this could simply reflect measurement variability due to factors like technique, fatigue, or scoring error. This is why the 49.17 cm figure is the best choice here. In interpretation, if a patient improves by, say, 10–20 cm on this test, you wouldn’t yet regard that as a definitive real change; you’d need a larger difference closer to or exceeding the MDC to be confident it’s beyond measurement error. The MDC is test-specific and population-specific, which is why this particular distance threshold is tied to this exact test setup.

Minimal detectable change is the smallest amount of change that exceeds the expected measurement error for a test, with a chosen level of confidence (often 95%). It’s derived from the test’s reliability and variability: MDC at 95% confidence is calculated from the standard error of measurement (SEM), which themselves come from the test’s standard deviation and reliability (ICC). In practice, MDC tells you how much a patient’s score must change before you can be confident that the change reflects a real difference rather than noise or measurement error.

For the single limb crossover hop for distance, the MDC95 value reported in the relevant data is 49.17 cm. This means that, for an individual, an improvement or decline of about 49 cm or more is required before you can say with 95% confidence that there is a true change in performance. Changes smaller than this could simply reflect measurement variability due to factors like technique, fatigue, or scoring error. This is why the 49.17 cm figure is the best choice here.

In interpretation, if a patient improves by, say, 10–20 cm on this test, you wouldn’t yet regard that as a definitive real change; you’d need a larger difference closer to or exceeding the MDC to be confident it’s beyond measurement error. The MDC is test-specific and population-specific, which is why this particular distance threshold is tied to this exact test setup.