Need
AFOs are used to correct foot deformities and/or strengthen targeted muscle groups to promote proper ambulation. Incorrect fastening during donning results in a misaligned configuration of the foot in the orthotic. This allows for undesirable force distributions and movement. Incorrectly worn/secured AFOs will not only deviate from intended function but can cause further harm. In order to improve the reproducibility of proper use of the orthotic, the fastening mechanism involved in the donning (and doffing) of the device must be as user-friendly (simple and easy to use) as possible. The current fastening system consists of a Velcro® strap looped once through a D-ring to reduce the possibility of mechanical failure. The looping action adds difficultly to the donning and doffing process. The use of Velcro® can also get stuck to the user’s surroundings, such as carpet. Enhancing the mechanism in which an orthotic is fastened will reduce the possibility of user error during donning. This will increase the efficiency of the orthotic and ultimately improve the users’ ambulation.
Design Specifications
The new fastening device must comply with the following specifications:
1. Lightweight (with orthotic, mass < 35 ounces or 1kg)
2. Easy to both don and doff (process time (for average user) < 60 seconds)
3. Low maintenance (daily care duration < 60 seconds)
4. Acceptable aesthetics
5. Low cost (cost to user < $500 for the entire AFO)
6. Produces intended treatment
7. Durable
1. Figueiredo, Elyonara Mello. Efficacy of Ankle-Foot Orthoses on Gait of Children with Cerebral Palsy: Systematic Review. Pediatric Physical Therapy. 2008. Vol. 20, 3.
2. Davids, Jon R., Rowan, Ferris and Davis, Roy B. Indications for Orthoses to Improve Gait in Children With Cerebral Palsy . Journal of the American Academy of Orthopaedic Surgeons. 2007.
1. Lightweight (with orthotic, mass < 35 ounces or 1kg)
- The heavier the device the greater the (negative) impact on the user’s gait. Existing studies of AFO effectiveness use control groups of “normal” individuals walking barefoot because any additional weight, however small, causes gait alteration (1).
2. Easy to both don and doff (process time (for average user) < 60 seconds)
- Time spent donning/doffing an AFO is an inconvenience which encourages user avoidance.
- The ease of the process is critical for users with certain physical impairments, such as lack of dexterity (i.e. with the elderly) or lack of sensation.
- Some patients have difficulty controlling upper limbs, so the device should be able to fasten with only one arm.
3. Low maintenance (daily care duration < 60 seconds)
- Care of the AFO is the sole responsibility of the user. In order to encourage proper cleaning and care, UF-FD will be designed to minimize time and focus required of the user.
4. Acceptable aesthetics
- Psychosocial considerations dictate that in order to encourage the regular use of an AFO, an individual must not feel embarrassed or critically self-conscious as a result of wearing the device.
5. Low cost (cost to user < $500 for the entire AFO)
- Velcro® and a D-ring are common and affordable items. The chosen design must be financially competitive.
6. Produces intended treatment
- The UF-FD will not detract from intended treatment of prior AFOs.
7. Durable
- For children users, AFOs require replacement every 12-18 months as a result of natural development and growth (2). UF-FD must be able to last for this lifetime or longer.
1. Figueiredo, Elyonara Mello. Efficacy of Ankle-Foot Orthoses on Gait of Children with Cerebral Palsy: Systematic Review. Pediatric Physical Therapy. 2008. Vol. 20, 3.
2. Davids, Jon R., Rowan, Ferris and Davis, Roy B. Indications for Orthoses to Improve Gait in Children With Cerebral Palsy . Journal of the American Academy of Orthopaedic Surgeons. 2007.