Analysis of a kinetic multi-segment foot model part II: Kinetics and clinical implications

Abstract

Kinematic multi-segment foot models have seen increased use in clinical and research settings, but the addition of kinetics has been limited and hampered by measurement limitations and modeling assumptions. In this second of two companion papers, we complete the presentation and analysis of a three segment kinetic foot model by incorporating kinetic parameters and calculating joint moments and powers. The model was tested on 17 pediatric subjects (ages 7-18 years) during normal gait. Ground reaction forces were measured using two adjacent force platforms, requiring targeted walking and the creation of two sub-models to analyze ankle, midtarsal, and 1st metatarsophalangeal joints. Targeted walking resulted in only minimal kinematic and kinetic differences compared with walking at self selected speeds. Joint moments and powers were calculated and ensemble averages are presented as a normative database for comparison purposes. Ankle joint powers are shown to be overestimated when using a traditional single-segment foot model, as substantial angular velocities are attributed to the mid-tarsal joint. Power transfer is apparent between the 1st metatarsophalangeal and mid-tarsal joints in terminal stance/pre-swing. While the measurement approach presented here is limited to clinical populations with only minimal impairments, some elements of the model can also be incorporated into routine clinical gait analysis.

Extended foot-ankle musculoskeletal models for application in movement analysis

“…Nevertheless, the presented results are consistent with the available literature for the joint moments at the ankle, subtalar, midtarsal, and metatarsophalangeal joints (Scott & Winter 1993;Bruening et al 2012;Malaquias et al 2015).…”

“…Nevertheless, musculoskeletal models commonly describe it by simplified kinematic and dynamic models with three or fewer segments (Anderson & Pandy 2001;Bruening et al 2012). Being an intricate structure, a small number of segments is generally insufficient to capture the detail of human foot motion and joint loading (Neptune et al 2000).…”

Six degree-of-freedom analysis of hip, knee, ankle and foot provides updated understanding of biomechanical work during human walking

“…Siegel et al, 1996;Takahashi and Stanhope, 2013), which may undermine the energy-saving benefits of the Achilles tendon elastic recoil (Ishikawa et al, 2005;Sawicki and Ferris, 2008;Zelik et al, 2014). One possibility is that the foot absorbs substantial energy in rotation of the metatarsophalangeal joints (Bruening et al, 2012;MacWilliams et al, 2003), and that this dissipation is not beneficial to walking economy (Song and Geyer, 2011;Song et al, 2013). Perhaps this foot behavior is useful for other reasons (e.g.…”

Effects of foot modelling on the human ankle kinematics and dynamics

“…6(a)). Although considering multiple segments in the foot models can better capture the foot inter-segment movements and moments [4,11,17,18,27,29], our study shows that this modelling assumption does not have considerable effects on the ankle joint torque calculations in an inverse dynamics approach. Based on the dynamic formulations in Eqs.…”