Tibial Acceleration Reliability and Minimal Detectable Difference During Overground and Treadmill Running.

Area of Science:

• Biomechanics
• Sports Science
• Human Movement Analysis

Background:

• Accurate measurement of tibial acceleration is essential for valid running analysis.
• Understanding the reliability and minimal detectable difference (MDD) of these measurements is key to reducing experimental error.

Purpose of the Study:

• To assess the reliability and MDD of peak axial and peak resultant tibial acceleration during overground and treadmill running.
• To compare the impact of averaging 5 versus 10 trials on reliability and MDDs.
• To identify optimal measurement conditions for detecting small changes in tibial acceleration.

Main Methods:

• Nineteen participants underwent tibial acceleration measurement using accelerometers during overground and treadmill running.
• Peak axial and resultant tibial accelerations were calculated for each trial.
• Within-session reliability was determined using intraclass correlation coefficients, and MDDs were computed.

Main Results:

• Excellent within-session reliability (intraclass correlation coefficients = .95–.99) was observed across all conditions.
• MDDs ranged from 0.6–1.4 g for peak axial and 1.6–2.0 g for peak resultant tibial acceleration.
• Overground running yielded the lowest MDD for peak axial tibial acceleration.

Conclusions:

• High reliability supports the use of tibial acceleration measurements in running studies.
• Overground running appears more sensitive for detecting subtle changes in peak axial tibial acceleration.
• Averaging 10 trials offered minimal improvement in reliability but slightly reduced MDDs compared to averaging 5 trials.