Effect of step width manipulation on tibial stress during running

Area of Science:

• Biomechanics
• Orthopedics
• Sports Medicine

Background:

• Narrow step width is associated with tibial stress fractures.
• Understanding the biomechanical factors influencing tibial loading is crucial for injury prevention.

Purpose of the Study:

• To investigate the impact of varying step width on bone stresses within the tibia.
• To determine if modifying step width affects tibial loading patterns during running.

Main Methods:

• A standardized tibial model was used in 15 runners at preferred 5k running velocity.
• Three step width conditions were tested: preferred step width (PSW) and PSW ±5% of leg length.
• Inverse dynamics, musculoskeletal modeling, and beam theory estimated tibial stresses from force and 3-D motion data.

Main Results:

• Tibial stresses in the distal third significantly differed with step width manipulation (p=0.002).
• Increased step width linearly reduced posterior/medial compression (p=0.036, 0.003), anterior tension (p=0.029), and shear stress (p<0.001).

Conclusions:

• Running step width significantly influences tibial bone stresses.
• Wider step widths are associated with reduced tibial loading, potentially mitigating stress injury risk.
• Adjusting step width may be beneficial for runners experiencing or at risk of tibial stress injuries, particularly those with a crossover running style.