Step length is a common measurement taken during gait analyses. It allows one to determine asymmetries between the two legs, compare differences between subjects, and even compare intra-subject differences for changing parameters. Yet there has been little investigation of step length specifically and how it is modulated during walking. This dissertation explores the methods by which different groups of people modulate their step length. It was hypothesized that step length is modulated by several different means: increasing hip flexion and extension, increasing ankle-foot roll over arc length; increasing stance foot heel rise to further extend the trailing limb, and increasing pelvic rotation. Gait analyses were performed for able-bodied persons, race walkers, persons with bilateral trans-tibial amputation and persons with partial foot amputation. Along with temporospatial and kinematic data, ankle-foot roll over shapes and Segment Contributions to Step Length (SCSL) were determined. The SCSL analysis was introduced as a method to examine how each of the lower limb segments contributes to the overall step length and how these contributions vary for different walking conditions (e.g. different speeds or prosthetic devices). The SCSL analysis was also used to compare the differences in segment contributions between subject groups. Results found that for a range of step lengths, percent contribution of the lower limb segments was fairly constant for able-bodied walking. Persons with normal effective foot lengths (e.g. intact feet) are able to utilize the ankle-foot segment to modulate step length, while those with shorter effective foot lengths displayed higher percent contributions from other lower limb segments. Largest contributions for all subjects were from the shank and thigh segments, though differences in contribution by the trailing and leading limbs were observed between subject groups. Although an increase in pelvic rotation contributed to an increased step, it appears to play a smaller role than previous studies seem to suggest. The SCSL analysis is a simple tool to analyze step length contributions. By knowing the differences in segment contributions of persons with gait pathology, we can better determine what treatments or training procedures can improve upon gait.

Last modified

• 10/08/2018

Creator

• Pinata Hungspreugs Sessoms

DOI

• https://doi.org/10.21985/N23162

Subject

• Biomedical Engineering

Keyword

• walking
• motion analysis
• prostheses
• amputation
• step length
• gait

Date created

• 2008-12-04

Resource type

• Dissertation

Rights statement

• In Copyright