Below knee cast stresses and intra-cast pressures during normal walking
D J Pratt1, D I Rowley, P D Marshall
1Orthotics and Disability Research Centre, Derbyshire Royal Infirmary, UK.
Clinical Biomechanics (Bristol, Avon)
|August 7, 2013
Summary
This study quantified stresses in below-knee casts during walking. Findings reveal stress concentrations in unexpected areas, guiding improved cast design for better patient outcomes.
Area of Science:
- Orthopedics
- Biomechanics
- Materials Science
Background:
- Below-knee casts are crucial for fracture immobilization.
- Understanding cast stresses and pressures during ambulation is vital for optimizing design and patient care.
Purpose of the Study:
- To quantify cast stresses and intra-cast pressures in below-knee casts during normal walking.
- To evaluate the influence of various cast configurations on stress distribution.
- To provide data-driven recommendations for below-knee cast design and material selection.
Main Methods:
- Utilized a microcomputer and force plate system to analyze gait in 13 volunteers undergoing 21 tests.
- Investigated various below-knee cast configurations.
- Measured cast stresses and intra-cast pressures during normal walking.
Main Results:
- Identified high stresses in expected locations and also in anterior and posterior aspects of the upper cast.
- Demonstrated that well-fitting cast designs sufficiently control rotation.
- Indicated that modern casting materials necessitate greater attention to splint construction details compared to traditional plaster of Paris.
Conclusions:
- Cast design should prioritize rotational control, with articulating ankle components being suitable in most cases.
- For fixed-ankle casts, concentrate material at the foot-shank junction for rigidity.
- Emphasize splint construction details when using advanced casting materials for optimal performance.
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