Differences in Peak Impact Accelerations Among Foot Strike Patterns in Recreational Runners

Area of Science:

• Biomechanics
• Sports Medicine
• Wearable Technology

Background:

• Running-related injuries (RRIs) stem from training errors and abnormal biomechanics.
• Peak acceleration during impact loading is a key indicator of running biomechanics linked to RRIs.
• Foot strike patterns may influence impact load magnitude, but data from insole-embedded IMUs is limited.

Purpose of the Study:

• To compare peak acceleration signals across rearfoot (RFS), midfoot (MFS), and forefoot (FFS) strike patterns.
• To evaluate the efficacy of insole-embedded inertial measurement units (IMUs) in measuring these differences.
• To differentiate the biomechanical impact of various foot strike patterns using novel wearable technology.

Main Methods:

• Healthy runners (n=187) performed treadmill running at three speeds using their habitual foot strike pattern.
• Insole-embedded IMUs measured peak resultant, vertical, and anteroposterior accelerations.
• Foot strike patterns were identified via high-speed video and expert observation; data analyzed using mixed-effects models.

Main Results:

• 81% of participants were RFS. RFS showed higher peak resultant and vertical acceleration than FFS.
• MFS exhibited the highest resultant accelerations, significantly greater than FFS and RFS.
• FFS demonstrated the lowest peak accelerations in resultant and vertical directions; RFS had greater anteroposterior acceleration than FFS.

Conclusions:

• Runners should be analyzed based on distinct RFS, MFS, and FFS patterns, not grouped as RFS vs. non-RFS.
• Further research is needed to correlate insole-measured peak accelerations with RRI risk.
• Insole-embedded IMUs offer a viable method for assessing foot strike pattern-related impact loading differences.