| © Otto Bock

Literature review on the effects of ankle-foot orthoses after stroke

Dr. Andreas Kannenberg

| © Otto Bock

Stroke

2

destruction of brain tissue due to lack of local

perfusion

85% ischemic infarction

(blood clotting, thromboembolism)

15% hemorrhage

approx. 200,000 new stroke cases per year in

Germany (UK: 130,000 ; US: 750,000)

about 1 million stroke survivors in Germany with

disabilities and handicaps (US: 5 million)

most frequent cause of permanent disabilities

acquired in adult life

| © Otto Bock 3

Pareses after stroke

Depending on location and extend of the

infarction or hemorrhage the clinical symptoms

may vary from discreet pareses to hemiparesis or

hemiplegia.

Drop foot is a common sequela of stroke that

afftects about 40% of patients.

| © Otto Bock

Treatment of drop foot: Figure-8 elastic bandage

4

| © Otto Bock

Off-the-shelf ankle-foot orthoses (AFO)

5

plastic AFO (Ottobock 28U9) Carbon fiber AFO

Ottobock Walk On (28U11)

spring element

| © Otto Bock

Custom AFOs

6

| © Otto Bock

Evidence on effects of AFOs

7

Use of AFOs is controversial: Many professionals discourage the use

of orthoses as they believe them to prevent or delay recovery.

no consistent prescription or use in practice

only little evidence is available

| © Otto Bock

Review of the literature on AFO effects after stroke

8

Literature search in Pubmed

Search terms: ankle-foot orthosis + stroke

Ankle-foot orthosis: 587 citations

Ankle-foot orthosis + stroke: 98 citations

After title and abstract review 14 studies with 342 patients remained for

further analysis.

All trials studied immediate or short-term effects only. High variability in patient mobility.

All studies were cross-over trials with randomization of order of testing

(with or without orthosis, different types of orthoses [off-the-shelf,

custom, plastic, metal, hinged, non-hinged]).

Patient numbers 8 to 61 with no drop outs.

| © Otto Bock

Results: Walking speed (m/s) Average improvement: 20.1%

9

AFO No AFO

Study Mean SD Mean SD Difference p-value

Alvin et al. 1988 0.69 0.51 0.55 0.42 25.5% NR

Burdett et al. 1988 (1) 0.27 0.07 0.22 0.11 22.7% NR

Burdett et al. 1988 (2) 0.22 0.07 0.19 0.08 15.8% NR

Corcoran et al. 1970 (1) 0.84 0.19 0.74 0 13.5%

NR

Corcoran et al. 1970 (2) 0.83 0.2 0.74 0.21 12.2%

NR

de Wit et al. 2004 0.49 0.24 0.42 0.24 16.7% 0.02

Francheschini et al. 2003 0.36 0.12 0.26 0,12 38.5% <0.001

Gök et al. 2003 (1) 0.37 0.14 0.32 0.13 15.6% n.s.

Gök et al. 2003 (2) 0.41 0.16 0.32 0.13 28.1% <0.05

Hesse et al. 1996 0.43 0.21 0.33 0.17 30.3% 0.006

Hesse et al. 1999 0.33 0.15 0.32 0.17 3.1% n.s.

Simons et al. 2009 0.58 0.24 0.46 0.21 26.1% 0.05

Tyson et al. 2009 0.3 0.14 0.3 0.12 0.0% n.s.

Tyson et al. 2001 0.25 0.1 0.18 0.1 38.9% 0.000

Wang et al. 2005 (1) 0.71 0.34 0.61 0.27 16.4% 0.028

Wang et al. 2005 (2) 0.69 0.41 0.58 0.29 19.0% n.s.

| © Otto Bock

Results: Paretic side step or stride length (m) Average improvement: 10.3%

10

AFO No AFO

Study Mean SD Mean SD Difference p-value

Alvin et al. 1988 0.74 0.39 0.64 0.35 15.6% NR

Burdett et al. 1988 (1) 0.34 0.09 0.31 0.09 9.7% NR

Burdett et al. 1988 (2) 0.33 0.1 0.3 0.11 10.0% NR

Gök et al. 2003 (1) 0.37 0.08 0.33 0.08 12.1% <0.05

Gök et al. 2003 (2) 0.37 0.08 0.33 0.08 12.1% <0.05

Hesse et al. 1996 0.69 0.18 0.58 0.19 19.0% 0.006

Hesse et al. 1999 0.65 0.18 0.62 0.17 4.8% n.s.

Tyson et al. 2009 0.53 0.16 0.53 0.15 0.0% n.s.

Tyson et al. 2001 0.24 0.12 0.22 0.09 9.1% 0.005

| © Otto Bock

Results: Overall mobility (Functional Ambulation Categories)

Average improvement: 43.6%

11

AFO No AFO

Study Mean SD Mean SD Difference p-value

Simons et al. 2009 4.7 0.5 4 0.6 17.5%

<0.05

Tyson et al. 2009 1.56 0.59 1.1 0.31 41.8%

0.005

Tyson et al. 2001 3.84 0.7 2.24 1.01 71.4%

0.00

| © Otto Bock

Results: TUG and postural sway Average improvement: 16% / 11.8%

12

Timed up and Go AFO No AFO

Study Mean SD Mean SD Difference p-value

de Wit et al. 2004 25.6 11.7 29.2 12.9 -12.3% 0.0000

Simons et al. 2009 23.4 9.7 29.1 12.9 -19.6% <0.05

Postural sway AFO No AFO

Study Mean SD Mean SD Difference p-value

Alvin et al. 1988 28.96 9.77 37.93 14.48 -23.6% NR

Chen et al. 1999 44.2 21.2 48.4 13.8 -8.7% n.s.

Pohl et al. 2006 12.5 5.2 15.7 6.7 -20.4% <0.05

Wang et al. 2005 (1) 0.31 0.24 0.31 0.25 0.0% n.s.

Wang et al. 2005 (2) 0.29 0.2 0.31 0.16 -6.5% n.s.

But: Other parameters representative of balance and stability showed

significant improvements.

| © Otto Bock

Results: Time to complete one flight of stairs Average improvement: 13.5%

13

AFO No AFO

Study Mean SD Mean SD

Differenc

e p-value

Corcoran et al. 1970 (1) 16.1 4.4 19.7 6.87 -18.3%

NR

Corcoran et al. 1970 (2)

17.2 5.3 19.7 6.87 -12.7% NR

de Wit et al. 2004 73 37.8 80.61 44.4 -9.4% 0.004

| © Otto Bock

Results: Energy consumption Improvement: 35.5%

14

AFO No AFO

Study Mean SD Mean SD Difference p-value

Francheschini et al. 2003 0.49 0.2 0.76 0.41 -35.5% <0.01

| © Otto Bock

Discussion

15

Results are confirmed by a recently published systematic review of

AFO effects in drop foot after stroke:

Significant improvement in overall mobility / independent walking with

AFO: standardized mean difference (SMD) 1.34 FAC; p<.001

Significant improvement in walking speed: SMD .06 m/s; p<.0001

Significant improvement in step or stride length: SMD .28 m; p=.02

Trend to improve TUG: p=.09

Trend to improve time to negotiate stairs: p=.07

Balance: mixed results due to heterogeneity of study samples and

outcome measures

Tyson SF, Kent RM: Effects of an ankle-foot orthosis on balance and walking after stroke: A systematic review of the

literature. Arch Phys Med Rehabil 2013, e-pub ahead of print

| © Otto Bock

Conclusion

16

Ankle-foot orthoses can improve walking, overall mobility,

walking efficiency and balance after stroke.

However, studies of long-term effects and comparative trials of the various

types of AFOs in different subgroups of stroke patients are needed to

guide distinguished orthosis prescription.

| © Otto Bock

Thank you for your attention

Dr. Andreas Kannenberg │