Impact-Related Ground Reaction Forces Are More Strongly Associated With Some Running Injuries Than Others

Area of Science:

• Biomechanics
• Sports Medicine
• Running Injury Research

Background:

• Inconsistent associations between impact-related ground reaction force (GRF) variables and running injuries exist when injuries are grouped.
• Previous research indicates more consistent associations when focusing on specific running injuries.

Purpose of the Study:

• To compare GRF variables between healthy and injured runners.
• To analyze GRF variables within specific common running injuries.

Main Methods:

• 125 injured runners (patellofemoral pain, tibial bone stress injury, plantar fasciitis, Achilles tendinopathy, iliotibial band syndrome) and 65 healthy controls underwent instrumented treadmill testing.
• Key impact-related GRF variables measured: vertical average load rate (VALR), vertical instantaneous load rate (VILR), and vertical stiffness at initial loading (VSIL).
• Statistical comparisons (α = .05) and diagnostic cutoff thresholds were evaluated for grouped and specific injury cohorts.

Main Results:

• Overall injured runners showed significantly higher VALR, VILR, and VSIL compared to controls.
• Specific injuries like patellofemoral pain and plantar fasciitis exhibited significantly elevated VALR, VILR, and VSIL.
• VSIL was also significantly higher for Achilles tendinopathy.
• Individual injury analysis provided better diagnostic criteria than grouped analysis.

Conclusions:

• While impact variables are elevated in the overall injured group, these findings are driven by specific injuries.
• An injury-specific approach is crucial for identifying biomechanical risk factors in running injuries.
• Practitioners should consider addressing impact loading, particularly for patellofemoral pain and plantar fasciitis.