Northwestern University Feinberg School of Medicine

Northwestern University Prosthetics-Orthotics Center

Pilot Study: Junior Shape & Roll Prosthetic Foot for Children

Principal Investigators: Dudley S. Childress, PhD, and Steven A. Gard, PhD 

Project Director: Andrew H. Hansen, PhD 

Co-Investigators: Margrit R. Meier, PhD; Steven A. Steer, MS; Edward C. Grahn, BSME; Rebecca L. Stine, MS; and Dilip Thaker

Collaborators: Children's Memorial Hospital, Chicago, Illinois
Shrine Hospital for Children, Chicago, Illinois
Texas Scottish Rite Hospital for Children, Dallas, Texas

Funded by: National Institute on Disability and Rehabilitation Research (NIDRR)

Status: Completed

Purpose

At present, most children's prosthesis components are scaled-down versions of the devices that were engineered with adult requirements in mind. However, the little data that are available suggest that children have distinctive features, different from adults that should be taken into account when designing prosthetic components [1-2]. The number of prosthetic feet designed specifically for the need of children is small in industrialized countries and almost non-existent in low-income countries. Thus, there is a need for highly functional and inexpensive prosthetic feet that can be easily customized for the specific biomechanical requirements of children. In this study, we are examining the roll-over shapes of the ankle-foot systems of non-disabled children and will use the results to design a prosthetic foot that takes the specific biomechanical requirements of children into account.

Methodology

Walking data (stripped of identifiers) will be gathered from existing databases at other centers including Children's Memorial Hospital in Chicago and the Shrine Hospital for Children in Chicago. These data will be processed as described previously [3] to obtain ankle-foot roll-over shapes of able-bodied children. The roll-over shapes will be fitted with circular arcs to determine their best-fit radii. These radii will then be used to design prosthetic feet that are appropriate for children depending on their height, weight, and age, using similar design principles as for the adult Shape&Roll prosthetic foot. The design methodology assumes that the ideal roll-over shape for a prosthetic foot is that of an able-bodied ankle-foot system.

Results

Children's Memorial Hospital in Chicago has shared walking data on sixteen children ranging in age from four to seventeen years. More data will be collected and processed before results are reported.

References

[1] Schneider et al. (1993) J Biomech 26(10): 1191-1204.[2] Sutherland et al. (1988) The development of mature walking. Mac Keith Press, Oxford Blackwell Scientific Publications Ltd. Philadelphia, USA.[3] Hansen et al. (2004) Clin Biomech 19(4): 407-414.

Related Publications

Hansen AH, Meier MR. Roll-over shapes of the ankle-foot and knee-ankle-foot systems of able-bodied children. Clin Biomech (Bristol, Avon). Dec 14 2010; 25:248-255.

Hansen A, Meier M, Childress D. Roll-over Shape Radii of Able-bodied Children. Paper presented at: 12th World Congress of the International Society for Prosthetics and Orthotics; July 29-August 3, 2007; Vancouver, Canada.