Bone strain in the equine tibia: an in vivo strain gauge analysis

Area of Science:

• Biomechanics
• Equine Orthopedics
• Veterinary Surgery

Background:

• Understanding tibial loading is crucial for equine limb health and injury prevention.
• Previous studies have focused on overall limb impact, with less detail on specific tibial surface strains.
• The role of the cranial tibial muscle in modulating tibial biomechanics remains unclear.

Purpose of the Study:

• To quantify surface strains on the equine tibia during walking.
• To investigate the combined effects of bending and torsion on the tibia.
• To assess the contribution of the cranial tibial muscle to tibial strain reduction.

Main Methods:

• Rosette strain gauges were affixed to the cranial, caudal, and medial surfaces of the tibia in adult ponies.
• Strain patterns were analyzed during walking.
• Measurements were repeated after surgical transection of the cranial tibial muscle.

Main Results:

• The caudal tibia experienced 1.5 times greater compressive strain than tensile strain on the cranial tibia.
• Principal strains deviated from the long axis, suggesting superimposed torsion on craniocaudal bending.
• Transection of the cranial tibial muscle did not significantly alter the measured strain patterns.

Conclusions:

• Equine tibial loading during walking involves complex interactions of bending and torsion.
• The cranial tibial muscle plays a minimal role in reducing tibial cortical strain.
• These findings enhance our understanding of equine limb biomechanics and potential injury mechanisms.