Study supports plantar fasciitis orthotic relief

[Guest guest]

Study supports plantar fasciitis orthotic relief

http://www.biomech.com/showArticle.jhtml?articleID=199600545

By: Tinley, PhD, Breidahl, MBBS, MRCP, and Will,

MBBS, FRACP

Plantar fasciitis is a common condition that presents clinically as

pain in the arch or, more commonly, as pain within the heel.

Bordelon1 describes plantar fasciitis as " a clinical syndrome

characterized by unilateral or bilateral heel pain in the medial

tubercle of the calcaneous. " However, other sites of pain have been

described within the syndrome.2

Although plantar fasciitis has been well described, Singh et al3

pointed out that " little is known about its underlying disease

process or its natural evolution. " Taunton et al2 suggested that " a

calcaneal spur can also be present, and this is thought to be the

result of periosteal detachment, hemorrhage and osteoblastic

activity. " Recent use of ultrasound in the diagnosis of plantar

fasciitis4 has clearly shown soft tissue swelling, confirming that

this condition is a multitissue disease process.

A number of treatments have been used for plantar fasciitis,

including night splints,5 surgery,6 custom and prefabricated

orthoses,7 and steroid injections,8 with varying degrees of success.

Prefabricated orthoses appear to be the most commonly used treatment

option as they are readily available from pharmacies, shoe stores,

and selected health professionals.

The pain experienced by the patient with plantar fasciitis is often

extreme, and sufferers complain of disability, loss of work time,

and reduced activity. Until recently, assessment of the effect the

condition has on general health and function has been poorly

researched,7 with pain being seen as the major factor in its

presentation. The importance of general foot health in terms of

pain, disability, and activity needs to be considered as a

significant indicator of treatment success.

Foot function indices (FFIs) such as those developed by Budiman-Mak,

Conrad, and Roach9 have proven to be effective methods of evaluating

foot function. FFI measures are divided into three main areas or

subscales (i.e., pain, disability, and activity) and are based on a

line measurement with defined parameters. A total of nine pain

scores, nine disability scores, and five activity scores are used.

The disability subscale of the FFI is shown in Table 1.

Background and methodology

The purpose of our study was to determine the effect of " off-the-

shelf " orthoses in the short-term treatment of plantar fasciitis as

measured by the FFI. The study was the first stage of a larger,

ongoing trial on injection therapy.

The study methodology comprised six main areas: clinical diagnosis,

imaging diagnosis, patient characteristics, FFI, clinical/orthopedic

measurements, and orthoses.

Clinical diagnosis. Patients presenting with the clinical symptoms

of plantar fasciitis were examined for the presence of unilateral or

bilateral palpable heel pain and evaluated for other possible heel

pain conditions; rheumatic conditions were excluded by blood test.

Subjects with a history of foot injury were excluded from the study.

Imaging diagnosis. All patients underwent an isotopic bone scan to

confirm the presence of an osteitis in the medial plantar heel

insertion point of the plantar fascia. An ultrasound of the affected

heel(s) was conducted at the time of initial presentation and before

orthotic therapy commenced. At the time of presentation, male

patients showed a plantar fascia thickness of 4.25 mm plus/minus 1.4

mm and female patients had a plantar fascia thickness of 4.39

plus/minus 1.51 mm. Ultrasonography was repeated 12 weeks later to

confirm the diagnosis that the plantar fascia had thickened.

Patient characteristics. The 34 study subjects comprised 13 men and

21 women. Disease duration was 21.5 plus/minus 22.94 months. A

summary of the patients' characteristics, including height, weight,

body mass index (BMI), and age is shown in Table 2.

FFI. A baseline measurement was recorded. In addition, all patients

received an FFI at the 12-week follow-up.

Clinical/orthopedic measurements. Standardized orthopedic

measurements10 were taken with an average of three repeat measures

to determine ankle joint neutral position, maximum dorsiflexion, and

maximum plantar flexion. In addition, the nonweight-bearing neutral,

maximum inversion, and maximum eversion positions of the subtalar

joint were recorded.

Midtarsal joint pronation, or flattening of the medial arch, was

recorded via the navicular drop measurement. This test was repeated

three times and an average score was calculated for each subject. In

this measurement, the patient rises from a seated, neutral,

semiweight-bearing position into a fully compensated weight-bearing

position. A skin marker positioned over the navicular prominence is

used to determine vertical displacement between the semiweight-

bearing and weight-bearing positions.11

Orthoses. After a diagnosis of plantar fasciitis was made, study

subjects were issued one pair of off-the-shelf Vasyli (Vasyli

International, Queensland, Australia) medium-density arch-support

orthoses (Figure 2). These devices were adjusted to fit their

footwear. Patients were advised to wear the orthoses at all times

when weight-bearing, and were provided footwear guidance. After

wearing the orthoses for 12 weeks, they were reevaluated.

Statistical analysis and results

Statistical analysis was performed using SPSS (SPSS Inc., Chicago)

statistical analysis software. Values are stated as mean plus/minus

standard error of the mean (SEM) with a 95% confidence interval

(CI). A paired sample t-test and analysis of variance (ANOVA) was

used. A P value of < .05 was considered significant.

Results of the t-tests clearly showed that patients' pain,

disability, and activity scores were all reduced. It is important to

note that the reduction in the activity score indicates that the

patients' activity levels had improved after introduction of the

orthoses.

A significant reduction in all FFI scores was observed, with over

90% of patients showing significant or total relief of plantar

fasciitis symptoms. However, not all subjects had complete symptom

resolution. In terms of activity levels, 67% of subjects reported a

significant improvement. Similar results were seen in the disability

indicator.

Pre- and post-treatment ultrasound measurements showed that the

plantar fascia thickness returned to normal levels of thickness

(defined as less than 3 mm).

Bone scans were positive in all cases, and soft tissue scans showed

increased flow to the sole of the feet of all patients.

Analysis of patient characteristics

All independent data points were tested statistically for

correlation using an ANOVA. Only significant results are presented

here.

The right foot plantar fascia thickness data showed significant (r

< .05, P < .05) correlation with BMI. An increase in this parameter

would appear to be directly related to an increase in plantar fascia

thickness. However, the left foot plantar fascia thickness showed no

relationship with any of the patient characteristics, or

clinical/orthopedic measures. No correlation was found between any

of the ankle or subtalar joint measurements and plantar fascia

thickness, FFIs, BMI, etc.

The navicular drop measurement was not predictive of any of the

variables in either foot. Patients with flatter feet did not appear

to experience greater levels of pain and disability.

Discussion

This paper represents the first stage of a larger study, " Local

corticosteroid injection therapy in plantar fasciitis: a randomized

controlled trial. " The purpose of this study was to provide a

standard pretreatment before the subjects went on to the second,

double-blind stage, where they would receive corticosteroid

injection or lignocaine injection therapy. This research was worthy

of independent presentation because of significant results that were

obtained using standardized podiatric therapy. Among the study's

subjects, 70% (as defined by the FFI total scores) had significant

resolution of their plantar fasciitis symptoms, and did not progress

to the second stage of the study. The remaining 30% moved into the

injection trial.

A limitation of the research presented here is that no controls were

used, because the initial aim of the overall study was to

investigate corticosteroid therapy in the double-blind stage. In

support of the methodology used is the fact that prior to joining

the study, patients had plantar fasciitis symptoms for 21 months on

average and had not shown any improvement during this period. Use of

the FFI at presentation and at the 12-week follow-up allowed before

and after intervention comparison; this ensured that each patient

acted as his or her own control subject.

It could be argued that some patients might have seen improvement

over the study's 12-week time frame. This seems unlikely, given the

length of time they had experienced pain and disability prior to the

study (e.g., disease duration was 21.5 plus/minus 22.94 months).

However, the time frame can be regarded as a limitation of the

study. All subjects presented with an average plantar fascia

thickness of 4.3 mm, which was greater than the normal thickness of

3 mm, as indicated in the medical literature.12,13 It is for this

reason that the study was deemed worthy of presentation at this

time. Research is ongoing and consideration is being made for the

use of randomized controls.

Common sense would suggest that a foot that has more

pronation/eversion accompanied by flattening of the arch on weight-

bearing would be more prone to plantar fasciitis. However, none of

the foot motion variables showed correlation with pain, disability,

activity levels, or plantar fascia thickness.

Dorsiflexion at the ankle joint motion also has been linked with

lowering of the arch, as pronation is considered a compensation for

limited dorsiflexion. In this population there was no correlation

between these factors. Limited dorsiflexion did not equate to higher

navicular drop values.

The type of feet seen in this study population varied greatly and

included inverted, normal, and everted subtalar joint position.

Again no correlation was seen between these factors and pain,

disability, activity levels, or navicular drop values. This would

confirm the limited clinical value of foot measurement techniques in

predicting foot problems.

Of no surprise is the significant correlation between plantar fascia

thickness and the apparent increase in BMI, a finding supported by

the literature.14 However, in this study a correlation is only

evident in the right foot and not in the left foot. This is a

mystery that may be due to environmental factors such as driving a

car (increased foot function on the accelerator). Or it may be that

the greater incidence of right-handedness in the population

corresponds to a greater incidence of right-footedness.

Conclusion

Simple off-the-shelf orthoses, in the form of Vasyli arch supports,

had a significant effect on plantar fasciitis symptoms in this

patient group. While this finding supports the current

literature,7,15 the effect may be short-term and requires further

research. The results suggest that clinical measures of the foot

have little or no value as predictors of the level of plantar fascia

thickness, or pain, disability, or reduced activity seen in the

plantar fasciitis patient. The navicular drop measurement is a

reliable evaluation of foot posture.10 However, it would appear to

have no correlation with any of the variables measured.

Flatter feet do not seem to produce a thicker plantar fascia or

cause more pain, greater disability, or a reduction in activity. The

only factor that seems to be correlated with increased plantar

fascia thickness is an increase in a patient's BMI.14 However, in

this group, correlation with that factor showed only in the right

foot, a curious finding that deserves further research.

Tinley, PhD, is with the department of podiatry at Curtin

University in Bentley, Perth, Western Australia. Breidahl,

MBBS, MRCP, is a consultant radiologist, and Will, MBBS,

FRACP, is a consultant rheumatologist, both at the Royal Perth

Hospital in Perth, Western Australia.

Acknowledgments

We would like to thank the staff and students in the podiatry

department at Curtin University for their help with this study. We

also thank Vasyli International for the supply of orthoses.

References

Bordelon RL. Subcalcaneal pain: a method of evaluation and plan for

treatment. Clin Orthop Relat Res 1983;(177):49-53.

Taunton JE, Clement DB, McNicol K. Plantar fasciitis in runners. Can

J Appl Sport Sci 1982;7:41-44.

Singh D, Angel J, Bentley G, Trevino SG. Plantar fasciitis. BMJ

1996;315(7101):172-175.

Bygrave CJ, Betts RP, Saxelby J. Diagnosing plantar fasciitis with

ultrasound using Planscan. Foot 1998;8(3):141-146.

Wapner KL, Sharkey PF. The use of night splints for the treatment of

recalcitrant plantar fasciitis. Foot Ankle 1991;12(3):135-137.

Green D, Brekke M, J. What is the best surgical approach

for heel spur syndrome. Podiatry Today 2000;13(10):39-43.

Pfeffer G, Bacchetti P, Deland J, et al. Comparison of custom and

prefabricated orthoses in the initial treatment of proximal plantar

fasciitis. Foot Ankle Int 1999;20(4):214-221.

Crawford F, Atkins D, Young P, J. Steroid injection for heel

pain: evidence of short-term effectiveness. A randomized controlled

trial. Rheumatology (Oxford) 1999;38(10):974-977.

Budiman-Mak E, Conrad KJ, Roach KE. The foot function index: a

measure of foot pain and disability. J Clin Epidemiol 1991;44(6):561-

570.

Tinley P. Two and Three Dimensional Assessment of the Foot and

Ankle. [PhD thesis]. Brisbane, Australia: Queensland University of

Technology; 1998.

Vinicombe A, Raspovic A, Menz HB. Reliability of navicular

displacement measurement as a clinical indicator of foot posture. J

Am Podiat Med Assoc 2001;91(5):262-268.

Gibbon WW, Long G. Ultrasound of the plantar aponeurosis (fascia).

Skeletal Radiol 1999;28:21-26.

Kane, D, Greaney T, Shanahan M, et al. The role of ultrasonography

in the diagnosis and management of idiopathic plantar fasciitis.

Rheumatology (Oxford) 2001;40(9):1002-1008.

Hill JJ Jr, Cutting PJ. Heel pain and body weight. Foot Ankle 1989;9

(5):254-256.

Landorf K, Keenan A, Rushworth L, Griffiths R. Effectiveness of foot

orthoses in the treatment of plantar fasciitis: a randomized

controlled trial. Presented at the 19th Australiasian Podiatry

Conference; Canberra, Australia; 2001:66-67.

TABLE 1. FOOT FUNCTION INDEX: DISABILITY SUBSCALE How much

difficulty do you have

Walking in house?

Walking outside?

Walking four blocks?

Climbing stairs?

Descending stairs?

Standing tip-toe?

Getting up from a chair?

Climbing curbs?

Walking fast?

Respondents are asked to answer each question on a one to 10 scale,

with one corresponding to " no difficulty " and 10 corresponding

to " unable to do. "

Source: Reference #9