Point-Counterpoint: Do AFOs Have A Role In Fall Prevention?
A targeted low-tech approach can be helpful in assessing any patient’s sensorimotor abilities. I recommend ascertaining a simple fall history and a clinical test called the “Timed-Up-and-Go” test for screening.24 It involves timing a patient getting up from a chair, walking 3 meters, turning around to return to the chair and sitting back down. The validated tool is very useful in determining patients who are most at risk for falling.24 A Timed-Up-and-Go time greater than 14 seconds is abnormal for community seniors and warrants further assessment.24
I recommend a treatment program that educates the patient and family, eliminates home obstacles, addresses individual sensorimotor deficiencies (including lower extremity issues) and promotes regular exercise. Such multifactorial programs have demonstrated significant fall risk reduction.25,26 The prescribed use of AFOs for fall prevention is particularly well documented in elderly post-stroke patients. A recent meta-analysis of 20 clinical trials involving 314 post-stoke patients with AFOs showed improved lower extremity kinematics, kinetics and energy cost in walking.27
Patients who fall often are psychologically compromised. They may self-restrict their activities, which can lead to further deconditioning. Patients need to overcome this loss of confidence for long-term success. Ankle-foot orthoses can restore that confidence along with gait velocity and the functional improvement that results in a transition to a higher level of ambulation and quality of life.28,29 However, to improve adherence, the device needs to be easy to use, fit easily into standard shoes and be made of lightweight materials for patients to avoid fatigue.
What You Should Know About Prescribing AFOs In Older Patients
Like many current treatments in medicine, there is a need for continued research in lower extremity compromised elderly patients. While there is anecdotal clinical evidence of efficacy and benefit of dynamic AFOs, more formal investigations are warranted to show measurable benefit and permit refinement of brace designs.
There has been some recent confusion around the indication and prescription of custom AFO therapy in older adults. One should never prescribe custom braces in a prophylactic manner to prevent falls. For clarification, a list of common indications for prescribing custom AFOs includes: muscle weakness, ataxia, gait abnormality, joint instability, difficulty walking, peripheral neuropathy, limb pain, arthropathy and hemiplegia. Treating these conditions as outlined will have a benefit in reducing fall risk but not totally eliminate falls.
The question often arises: how do we justify bilateral use of these braces in patients with these lower extremity deficiencies? First, one needs to document bilateral involvement. Furthermore, one can chart subjective and objective clinical benefit, including retesting Timed Up and Go times if necessary. Additionally, there is literature to support this treatment application as dynamic bilateral AFO support has had successful testing in multiple sclerosis patients, who have similar balance disorder profiles to that of compromised elderly patients.30,31 It is important to note that static AFOs, which restrict ankle motion during the stance phase of gait, do not perform well functionally.31-33 Static AFOs can potentially cause increased limitations on soft surfaces and therefore one should avoid them when possible.31-33
Why can’t we use over-the-counter AFOs instead of custom devices? There is evidence that demonstrates a custom dynamic AFO that maximizes arch contour and leg surface area can show immediate clinical benefit.34 The flexible AFO brace design provides sagittal plane flexibility to preserve ankle motion while maintaining frontal plane support. The upper portion of the brace also provides important tactile stimulus to the leg that improves proprioceptive sense and postural stability.35
An individual’s fall risk depends on the frequency of imbalance episodes he or she encounters in daily activities, and his or her ability to recover from these balance-threatening situations.