What is an AFO?
An AFO, or Ankle Foot Orthosis, is a splint that helps keep the foot and ankle in a good position for walking and standing. AFOs can be worn on one or both feet and may have a joint or hinge at the ankle (this would make it a dynamic ankle foot orthosis, a DAFO) or be fixed in one position (AFO).
Why are AFOs used?
An AFO is used to:
- Support weakened joints or muscles e.g. footdrop or weakness controlling the knee
- Control abnormal muscle tone e.g. low or high muscle tone (spasticity)
- Prevent abnormal motion
- Reduce pain
- Increase stability and control of the foot, ankle and knee
Q/ Why does an AFO need a heel post?
A heel post maybe added to an ankle-foot-orthosis or DAFO to alter the angle of the lower leg and improve the way the user walks.
This is often referred to as ‘tuning’ the splint.
Another reason for adding a heel post to an AFO is to accommodate tightness or contractures at the foot and ankle which can cause the foot to point downward, sometimes causing the person to walk on the ball of their foot.
Toe-Walking
An ankle-foot orthosis (AFO) can help children and adults with toe walking by correcting their alignment and improving their walking patterns.
AFOs can be used during the day or night to:
- Help stretch the calf muscles and achilles tendon
- Maintain range of motion in the calf
- Prevent the foot and ankle from being pushed down, which can help prevent the development of a toe-walking gait
- Improve walking patterns and encourage a flat foot position
Adding a heel post ‘fills’ the gap between the heel and the floor allowing weight to be more evenly distributed through the foot. This will reduce pressure at the ball of the foot whilst maintaining the best angle of the lower leg and knee above.
Q/ What does shank vertical angle (SVA) mean?
A Shank vertical angle is a term often used by Orthotists and Physiotherapists when assessing gait and posture. It describes the angle of the lower leg in relation to the foot on the floor during standing and walking. The SVA is very important as it contributes to stability in stance by placing the knee joint centre over the centre of the foot, creating a triangular base of support.
Generally, the optimal SVA is 10-12 degrees inclined (leaning forwards). This can be achieved by posting the AFO, altering the pitch of the shoe or a combination of both.
Conclusion
The SVA achieved by adding a heel post and/ or in conjunction with the correct footwear is critical in gaining the best possible clinical outcome from any orthosis e.g. AFO,DAFO of KAFO.
Our clinicians will use both physical and digital measuring techniques to attain the best functional results, whilst always keeping our clients informed of our clinical rationale.
All the AFOs we provide are created and fitted to the individual’s specific needs and can even be customised with a unique colour and pattern using the most up to date technology.
If you need help with an AFO for your or your child please get in touch with our friendly team.
You can visit our Orthotics Clinic at our clinics in Northlight, Nelson for a full assessment and fitting