Foot plantar distribution and kinematic analysis of low dive in soccer goalkeepers: a case study

Purpose: Goalkeepers require fast, precise movements combining explosive force and neuromuscular control. While previous studies [1] analyzed diving using force platforms and optical motion capture, they lack detailed insight into how forces are distributed across different regions of the foot during a dive. To address this gap, we investigated plantar pressure distribution and lower-limb kinematics in an elite female goalkeeper performing low-corner dives, using wearable inertial sensors and sensorized pressure insoles. Methods: An 18-year-old goalkeeper from an elite youth team performed four randomized low dives (two per side) intercepting balls launched at approximately 30 cm height and 70 cm from the goal post. Kinematic data were recorded at 60 Hz with the Xsens MVN Biomech Link system (17 IMUs) and plantar pressures at 100 Hz using XSENSOR® smart insoles. A distinctive foot-strike acceleration peak was used as a synchronization marker across all devices. Time series were normalized from peak hip flexion to ipsilateral foot take-off, and analysis focused on stance width (normalized to leg length), joint angles (hip, knee, ankle), vertical ground reaction forces, and regional plantar pressures at four key instants: preparatory phase, ipsilateral foot initial contact (IFIC), contralateral peak force (CPF), and ipsilateral peak force (IPF). Given the exploratory nature and small sample size, data are presented descriptively without inferential statistics. Results: In the preparatory phase (0%), vertical ground reaction force was ~640 N, evenly distributed. Peak pressure occurred under metatarsals (136 N) and toes (126 N); stance width was 44%, with 105° hip flexion, 59° knee flexion, and 17° ankle dorsiflexion. At IFIC (~48%), contralateral force rose to 341 N, with pressure shifting to midfoot/metatarsals. Stance width increased to 56%, hip flexion reduced to 93°, and ankle dorsiflexion to 11°. At CPF (~76%), forefoot force peaked at 470 N, stance width reached 84%, and ankle dorsiflexion peaked at 27°. At IPF (~84%), ipsilateral load peaked at 403 N under metatarsals; hip and knee reached maximum extension (118°, 114°), and ankle dorsiflexion was 28°. Conclusions: Sequential loading confirms differentiated roles of contralateral (propulsion) and ipsilateral (control) limbs. These findings highlight the potential of portable sensor technologies to inform targeted coaching, neuromuscular training, and injury prevention programs, particularly by optimizing forefoot loading strategies and ankle stability. Acknowledgments: The authors would like to thank Alessandro Colombo and Daniele Airoldi for their participation in the study. References: [1] Ibrahim, R., et al. (2020). Angular Velocity, Moment, and Power Analysis of the Ankle, Knee, and Hip Joints in the Goalkeeper’s Diving Save in Football. Frontiers in Sports and Active Living, 2, 13.