What type of orthotic device, specifically an ankle-foot orthosis (AFO), is used to manage foot drop?

Ankle-Foot Orthosis (AFO) for Foot Drop

An ankle-foot orthosis (AFO) is the primary orthotic device used for foot drop, with functional electrical stimulation (FES) as an equally effective alternative first-line option. 1, 2

Primary Device: Ankle-Foot Orthosis (AFO)

The American Heart Association/American Stroke Association provides a Class I, Level B recommendation that AFOs should be used for ankle instability or dorsiflexor weakness. 1 This represents the highest level of guideline support for managing foot drop.

Mechanism and Benefits

• AFOs maintain the foot in a neutral position during the swing phase of gait, preventing toe dragging on the ground 2, 3
• They improve walking speed, step/stride length, and balance (weight distribution in standing) 1
• AFOs positively affect ankle kinematics, knee kinematics during stance phase, kinetics, and reduce energy cost of walking 1, 2
• They provide foot clearance during swing phase and maintain stable posture by allowing heel contact during stance phase 3

Commonly Used AFO Types

The most frequently prescribed AFO designs in clinical practice include: 3

• Plastic AFO: Traditional molded plastic conforming around posterior calf and plantar foot
• Carbon fiber AFO: Lightweight alternative with improved energy return
• Walking boot: Prefabricated option for temporary use
• UD-Flex: Flexible design allowing some ankle motion
• Dynamic hinged AFO: Allows controlled ankle movement but may induce some dependence compared to standard rigid AFO 1

Important Clinical Consideration

One small RCT found that while dynamic hinged AFOs improved ambulatory function over standard AFOs, they induced some dependence; the standard AFO group performed better after 3 months when walking without any orthosis. 1 This suggests that rigid AFOs may be preferable for long-term functional independence.

Alternative First-Line Option: Functional Electrical Stimulation (FES)

FES is recommended as a reasonable alternative to AFOs for foot drop management (Class IIa, Level A recommendation). 1, 2

FES Mechanism

• Electrically stimulates the peroneal nerve to activate ankle dorsiflexors during swing phase 2
• Can be delivered through surface electrodes placed over the common peroneal nerve 2
• Implantable nerve stimulators available for more severe or chronic cases 2

FES vs AFO Comparison

• Both are equally effective in improving gait speed 2, 4
• FES may provide better gait symmetry after 12 weeks of use (swing duration and step length symmetry) 4
• FES users perceive significant improvement in gait after 4 weeks, while AFO users report improvement only after 12 weeks 4
• FES provides active muscle contraction which may help maintain muscle mass compared to passive orthoses 2

Compliance and Fitting Considerations

Verification that the AFO fits correctly and comfortably is essential to improve compliance with regular use. 1 Poor fit is a common pitfall leading to device abandonment.

Additional Prevention Benefit

AFOs may also be beneficial in preventing ankle plantarflexion contractures, which can affect gait quality and safety. 1 Resting ankle splints used at night and during assisted standing may be considered for prevention of ankle contracture in the hemiplegic limb (Class IIb, Level B). 1

Integration with Rehabilitation

• AFO use should be combined with intensive, repetitive mobility-task training (Class I, Level A recommendation) 1, 2
• Circuit training in group therapy settings is reasonable to improve walking function 1, 2
• Cardiovascular exercise and strengthening interventions should be incorporated to improve gait capacity 1, 2