Bill Carlton, CO
UT Southwestern Prosthetic-Orthotic Program
Dallas, Texas
A number of lower limb functional risk factors arise with the onset of a stroke, difficulty
walking or a risk to fall (1) being perhaps the most obvious and dangerous. As a
secondary and contributing risk for walking difficulties, spasticity and contractures stand
out as sequellae of stroke (2). Horn, et al report their findings that certain specific
treatment protocols following a stroke can lead to specific and desirable outcomes (3). A
number of years of following stroke patients past their initial recovery and rehabilitation
have led to this inquiry into AFO efficacy for contracture prevention, in the presence of
post-stroke spasticity. Common definitions for spasticity include velocity dependent tonic
responses of muscles to stretch with increased muscle activity that defies desired
volitional control (4,5). This spasticity, often demonstrated as clonus in stroke patients,
varies in its potential to put the patient at risk for contracture development. Cooper, et al
reports that the relationship between spasticity and contracture is difficult to analyze (6).
Scales have been developed to measure spasticity; the most commonly used is the
Ashworth or modified Ashworth scale. It is acknowledged that very few orthotists utilize
a spasticity measurement scale in the course of their care to assess the stroke patient’s
spasticity.
The efforts that will be discussed in this presentation include a clinical follow-up on
patients seen 3-6 months following their stroke who presented with contractures that were
not seen in the acute stage. What will become apparent is the difficulty in determining
what impact AFO use might have on the picture of contracture development. Patients
who present to clinic with evidence of regular AFO use, community level ambulation,
and a 90-degree plantar flexion contracture demonstrate some degree of success and
failure. Other methods of reducing spasticity exist (7,8), but AFO use has a tendency to
measure out a contracture’s development. The act of walking does an excellent job of
delivering a resistive stretch to the plantar flexors, and yet a large of number of spastic
patients develop contractures while walking (9). X-rays demonstrate that a patient placed
in a short leg cast can plantar flex to a position greater than the clinical observation of the
cast might predict.
Definitive outcomes measurement of AFO use for post-stroke walking difficulties has
been guardedly positive- the patient still has a right to ask, “do I really need this brace?”-
he will generally get an endorsement from the literature (10,11,12). For the specific task
of preventing a contracture, it is suggested that orthotists consider assessing the patient’s
risk for contracture, followed with a well designed and fitted orthosis. A number of
design variables exist to assist with post-stroke AFO design (13,14,15). Once design and
fitting have taken place, the question of patient compliance becomes paramount. Methods
of measuring patient compliance have been developed (16); perhaps the concept of
educating and following the stroke patient regularly is the most important mechanism of
assessing any compliance issues. At 6 months follow-up, we have noted a percentage of
stroke patients fitted with AFOs, where a plantar flexion contracture existed in the face of
moveable spasticity. The contractures were at 90 degrees, the angle that the AFO was
fabricated and fitted to- some AFOs were hinged, some solid. In some cases, the solid
AFO was converted to hinged, but the contracture persisted. All patient were at least
household ambulators. This is certainly not presented as journal ready science- only a
prompt for discussion and consideration. References were gathered using PubMed.
Stroke, 31 (2000), pp. 1223–1229. Disabil Rehabil, 2001 Sep 10;23(13):549-58. Arch Phys Med Rehabil., 2005 Dec;86(12 Suppl 1):101-14 Eur Jrnl Neurol, 2002 May;9 Suppl 1:10-6; dicussion 53-61. J Neurol Neurosurg, Psychiatry. 2005 Jan;76(1):47-54 Clinical Rehabilitation, Volume 19, Number 7, October 2005, pp. 760-766(7) Neurosurgery, 55(5):1130-1137, November 2004 J Rehab Medicine, 2005 Jul;37(4):252-7. Clinical observation, Bill Carlton, CO- 2005 Arch Phys Med Rehabil., 2003 Jun;84(6):924-7 Clin Rehabil. 2004 Aug;18(5):550-7 Arch Phys Med Rehabil. 2001 Aug;82(8):1047-9 Orthot Prosthet 39 (1985), pp. 26–29. J Prosthet Orthot 5 (1993), pp. 21–24. Orthot Prosthet 41 (1987), pp. 23–28. Personal communication- Don Katz, CO- 2004
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