Forces acting in the forefoot during normal gait--an estimate

Area of Science:

• Biomechanics
• Orthopedics
• Human Anatomy

Background:

• Understanding forefoot forces is crucial for surgical planning and diagnosing foot pathomechanics.
• Existing data on internal forefoot forces during gait is limited.
• This study addresses the need for quantitative force estimations in the first and second rays.

Purpose of the Study:

• To estimate the forces acting on tendons and joints of the first and second rays of the forefoot during gait.
• To provide essential data for understanding foot physiology and pathology.

Main Methods:

• Calculated internal forces using published ground force distribution data and anthropometrical measurements.
• Determined equilibrium conditions in the sagittal plane for first and second ray joints.
• Utilized data from the second force peak of the stance phase.

Main Results:

• Flexor hallucis longus and brevis tendons exert significant forces (52% and 36% body weight).
• Peroneus longus muscle force exceeds 58% body weight.
• First metatarsal head experiences ~119% body weight; second metatarsal head experiences ~45% body weight with high bending moment.

Conclusions:

• High forces in first ray flexor tendons support the longitudinal arch.
• The second metatarsal bone is heavily loaded in bending, and its failure may occur if the first ray is compromised.
• These findings are vital for understanding foot function, pathology development, and surgical interventions.