The direct effects of variations in AFO stiffness on the kinematics and kinetics of gait

Weakness of the lower limb on one side of the body is common after stroke and affects the everyday lives of stroke survivors. Various therapies may be prescribed for the management of various lower extremity impairments and disabilities. One of the possibilities that can be of great value is an orthotic treatment, when used in combination with physical therapy. Briefly, orthoses, and in particular ankle-foot orthoses (AFOs), are externally applied devices designed to maintain the foot in a desirable position with respect to the shank. Currently, the prescription and design of orthoses is still based on the expertise of orthotists instead of based on evidence from scientific research. This is partly due to the lack of studies on: 1. Mechanical AFO characteristics. 2. The effects of different types of AFOs on gait. Performing gait analysis and quantifying the stiffness of different orthoses could lead to more knowledge about the stiffness of AFOs and a better understanding of their effects on gait. In turn, this could lead, with the aid of further study, to better matching up between AFO properties and gait deficits of stroke patients. In this study the following four custom-made orthoses were tested using three different instruments: 1. A solid AFO made of copolymer polypropylene & reinforced with carbon fibre inserts. 2. Posterior leaf spring (PLS) made of copolymer polypropylene. 3. SWIFT Cast with a six-layer Scotch back slab. 4. SWIFT Cast with an eight-layer Scotch back slab. The Instron test machine and a custom-made apparatus were used to quantify the stiffness of each type of orthosis in the sagittal plane. The Vicon motion capture system and four Kistler force plates were used to determine the immediate effects of the AFOs on kinematic and kinetic gait characteristics in the sagittal plane. To carry out the gait analysis, one able-bodied subject was recruited and asked to walk six meters in a straight line with conventional shoes and without orthosis and with shoes and each of the AFOs on the left leg.

Name dc:type.qualificationname

msc

Level dc:type.qualificationlevel

masters-pg

Grantor dc:publisher.institution

University of Strathclyde

Year dc:date.issued

2013

Author dc:creator

• Hagenbeek, Judith

DOI

10.48730/mvsh-8v98

Identifier

T13664

OAI identifier oai:identifier

oai:strathclyde:v405s9361