Inter-segmental foot motion during gait in end-stage lesser tarsometatarsal joint osteoarthritis: A comparative study using multi-segment foot model.

Objectives: The purpose of this study was to evaluate inter-segmental foot and ankle kinematics in patients with end-stage lesser tarsometatarsal (TMT) joint arthritis and to identify characteristic gait adaptations using a validated multi-segment foot model.

Methods: Twenty-five patients with radiographically confirmed end-stage lesser TMT arthritis and fifty age- and sex-matched healthy controls underwent three-dimensional gait analysis. A 15-marker DuPont Foot Model was used to capture segmental kinematics of the hallux, forefoot, and hindfoot. Temporal-spatial parameters and inter-segmental motions were compared between groups. Statistical parametric mapping (SPM) was used to assess phase-specific differences across the gait cycle.

Results: The TMT group demonstrated slower walking speeds, shorter stride lengths, and increased step width compared to controls. Significant alterations in inter-segmental kinematics included increased forefoot dorsiflexion and hallux extension during terminal stance, along with reduced sagittal and transverse range of motion (ROM) in the hindfoot and hallux segments. Coronal plane motion was relatively preserved. These findings suggest that sagittal and transverse plane impairments, rather than coronal changes, are predominant in this patient population. Increased forefoot-to-hindfoot motion may reflect medial column laxity, including potential first ray hypermobility, and compensatory adjustments for reduced midfoot stability.

Conclusion: End-stage lesser TMT joint arthritis significantly alters inter-segmental foot motion and spatiotemporal gait parameters. These biomechanical adaptations may reflect compensation for midfoot dysfunction and highlight the importance of addressing sagittal and transverse plane abnormalities in clinical management.