Thesis Format
Monograph
Degree
Master of Engineering Science
Program
Biomedical Engineering
Supervisor
Jenkyn, Thomas
Abstract
This study focuses on testing a clinically practical multi-segment foot model, in an optical motion capture laboratory, to analyse foot kinetics and the medial longitudinal arch (MLA) of the foot. The foot kinetics are analysed for differences between a control group with a normal/neutral arch foot anatomy, and two patient groups, one with a low arch in the foot (pes planus) and one with a high arch in the foot (pes cavus). The multi-segment foot model assesses four segments of the foot: hindfoot, midfoot, forefoot, and hallux. The joint moments for all segments in the x-axis (plantarflexion/dorsiflexion in the sagittal plane), y-axis (internal/external rotation in the transverse plane), z-axis (inversion/eversion in the frontal plane), and joint power in the sagittal plane were analysed for a full gait cycle, as well as the MLA height-to-length ratio. This study analysed ten adults with normal/neutral arch anatomy, five adults with pes planus, and three adults with pes cavus. Participants had auto-reflective markers placed on anatomical locations of the body, which were tracked by the optical motion capture cameras as the participants walked across a force plate at their typical walking speed. This multi-segment foot model precisely determined differences in the kinetics of the normal/neutral arch anatomy group and the two patient groups. The normal/neutral arch anatomy group showed agreement with other published multi-segment kinetic foot models, as well as strong test-retest relatability (r > 0.7), and all groups showed strong within-participant reliability. The model determined that the pes cavus group experiences a higher MLA height-to-length ratio throughout the gait cycle than the normal/neutral arch anatomy group and larger power in the forefoot and hindfoot during the push-off phase of gait. In contrast, the pes planus group experiences a lower MLA height-to-length ratio than the normal/neutral arch anatomy group, and lower power in the midfoot and hindfoot during the push-off phase of gait. The model is determined to be clinically practical and relevant for testing foot kinetics and evaluating differences between control and patient populations.
Summary for Lay Audience
Functional human motion in the clinical setting is tracked through optical motion tracking systems, which enables cameras to track the three-dimensional (3D) movement of body segments. The walking movement is tracked, which cycles in the pattern of the feet moving forward on the ground to move the whole body forward. The walking, gait, cycle begins with one foot striking the ground and ends when the same foot strikes the ground again. During human gait research, the foot has typically been regarded as a single rigid segment in modelling and analysis. The single segment is simplistic, yet irrelevant in gait analysis as it does not allow all important aspects of the foot motion during gait to be analysed. As a result, multi‑segment foot models, which divide the foot into multiple segments, are used for analysis. These models have largely only analysed how the segments move, and not the forces that cause the movements. The study of the forces that cause the movements is lacking for both normal anatomy populations, and populations with anatomy considered outside of the normal, such as a low arch or high arch in the foot. This study focuses on using a clinically friendly multi-segment foot model to determine the motions, forces, and powers in the foot and ankle during the gait cycle for the normal/neutral arch population and patient populations with low arches and high arches. It also determines the differences in the arch’s height‑to-length ratio during the gait cycle. The model divides the foot into four segments for analysis, including the hindfoot, midfoot, forefoot, and hallux. Participants had sticky markers placed on various locations of the body, which were tracked by the optical motion capture cameras as the participants walked at their normal speed across a walkway that collected the force of their foot hitting the group while they walked. Due to the low arch and high arch populations having anatomy outside of the normal, it is predicted that the motions, forces, and powers of these populations will be outside of the normal as well. Specifically, it is expected that the low arch population will have less support and thus less force and power, while the high arch population is expected to have more pressure, with higher force and power. The model did provide results that showed the differences between the normal arch, low arch, and high arch anatomy groups, with the predictions being validated. This model has provided previously unknown information on the motions, forces, and powers in the foot for different anatomy populations, and is clinically practical and relevant for gait analysis and evaluating differences between varying foot anatomy populations.
Recommended Citation
Smart, Emma, "A Multi-Segment Foot Model Analysis on Normal, Pes Planus and Pes Cavus Feet and Ankle Kinetics" (2024). Electronic Thesis and Dissertation Repository. 10576.
https://ir.lib.uwo.ca/etd/10576
