Athletes sprint maximally over 10 meters, decelerate, complete a 180° turn at the 15-meter marker (5m decel zone), then re-accelerate back through the 10m timing gates. Two left-foot and two right-foot turns performed (4 trials total).
Athletes sprint maximally over 10 meters, then perform a maximal deceleration to a full stop (no predetermined stopping point), followed by a backpedal to the 10m marker. Three trials performed. Timing gates at 10m signal deceleration start.
Schematic of the two assessments. Circles = cones, triangles = timing gates. Both tests use a 10m sprint approach. The 505 (top) has a fixed 15m cone for turning; the ADA (bottom) has no fixed stopping point — athletes decelerate to a self-selected stop before backpedalling.
Gardner-Altman plots for the 6 significantly different deceleration metrics (N=19 per test). Each line represents one participant. The right panel of each plot shows the bootstrapped paired mean difference (ADA minus 505) with 95% CI. Values below zero = 505 produced higher values; values above zero = ADA produced higher values.
• Heel strike upon ground contact to maximise braking effect
• Posteriorly oriented torso and slightly flexed knee/hip
• Longer brake step GCT (0.20 s) — more time per contact to apply braking force
• Foot 41 cm ahead of COM — greater forward reach to increase braking impulse
• No rotation, no lateral lean, no foot re-orientation required
• Shorter brake step GCT (0.18 s) — faster stepping to reach the known turn point
• Foot only 36 cm ahead of COM — closer foot placement driven by turn prep
• Additional lateral trunk flexion, internal foot progression angle
• Greater braking force (313.6 N) to arrest momentum before the fixed turn point
• Predetermined location acts like an external cue, improving motor planning and braking efficiency
Despite very different overall braking demands, hip flexion (33.3° vs. 32.3°, ES = 0.09) and knee flexion (34.2° vs. 33.1°, ES = 0.17) at ground contact were nearly identical between tests — suggesting sagittal plane joint kinematics may be relatively preserved regardless of test type.
COM drop (12.6 vs. 13.0 cm, ES = 0.08) and ground contact deceleration (11.2 vs. 11.0 g, ES = 0.13) also showed trivial between-test differences, indicating the overall lowering strategy was similar despite the different braking contexts.
Xsens MVN Awinda IMU System — 100 Hz sampling, “lower body with sternum” configuration. Units at foot, tibia, lateral thigh, posterior pelvis, and sternum.
This is the first study to compare these two deceleration tests using full-body IMU kinematic data, going beyond radar/laser-derived velocity metrics alone. Athlete Analytics software used for proprietary metric calculation.
① The 505 is a higher braking demand test than the ADA (at matched 10m approach). If the goal is to assess maximum braking capacity — including the neuromuscular and technical skill required to decelerate rapidly to a fixed turning point — the 505 presents a larger, different challenge. ES = 1.61–2.46 for force and deceleration metrics.
② The ADA isolates “pure” deceleration without turn complexity. If the aim is to assess horizontal braking ability without the confound of COD skill (rotation, foot re-orientation, trunk lean), the ADA is the more appropriate choice. Particularly valuable in rehabilitation progressions before re-introducing COD demands.
③ Do not use stopping distance or stopping time as primary outcome metrics. Both showed poor-to-moderate ICC (0.13–0.56) and very large MD thresholds. These metrics may reflect true biological variability in braking strategy, but the current evidence does not support their reliable use as standalone performance indicators with this technology.
④ Analyse individual brake steps, not just phase averages. This study averaged across all braking steps, but prior research shows large differences between early (antepenultimate), mid (penultimate), and final foot contacts in terms of force and GCT. Step-specific analysis could reveal more targeted insights about braking strategy deficiencies.
⑤ Use both tests together when the full picture is needed. As prior work showed that the ADA and 505 present different demands even at the same approach speed, combining both gives more complete insight — particularly for athletes whose sport involves both planned (505-like) and unplanned (ADA-like) decelerations.