Adam R. Bird

Diagnostic imaging for chronic plantar heel pain: a systematic review and meta-analysis

BackgroundChronic plantar heel pain (CPHP) is a generalised term used to describe a range of undifferentiated conditions affecting the plantar heel. Plantar fasciitis is reported as the most common cause and the terms are frequently used interchangeably in the literature. Diagnostic imaging has been used by many researchers and practitioners to investigate the involvement of specific anatomical structures in CPHP. These observations help to explain the underlying pathology of the disorder, and are of benefit in forming an accurate diagnosis and targeted treatment plan. The purpose of this systematic review was to investigate the diagnostic imaging features associated with CPHP, and evaluate study findings by meta-analysis where appropriate.MethodsBibliographic databases including Medline, Embase, CINAHL, SportDiscus and The Cochrane Library were searched electronically on March 25, 2009. Eligible articles were required to report imaging findings in participants with CPHP unrelated to inflammatory arthritis, and to compare these findings with a control group. Methodological quality was evaluated by use of the Quality Index as described by Downs and Black. Meta-analysis of study data was conducted where appropriate.ResultsPlantar fascia thickness as measured by ultrasonography was the most widely reported imaging feature. Meta-analysis revealed that the plantar fascia of CPHP participants was 2.16 mm thicker than control participants (95% CI = 1.60 to 2.71 mm, P < 0.001) and that CPHP participants were more likely to have plantar fascia thickness values greater than 4.0 mm (OR = 105.11, 95% CI = 3.09 to 3577.28, P = 0.01). CPHP participants were also more likely to show radiographic evidence of subcalcaneal spur than control participants (OR = 8.52, 95% CI = 4.08 to 17.77, P < 0.001).ConclusionThis systematic review has identified 23 studies investigating the diagnostic imaging appearance of the plantar fascia and inferior calcaneum in people with CPHP. Analysis of these studies found that people with CPHP are likely to have a thickened plantar fascia with associated fluid collection, and that thickness values >4.0 mm are diagnostic of plantar fasciitis. Additionally, subcalcaneal spur formation is strongly associated with pain beneath the heel.

The effect of foot wedging on electromyographic activity in the erector spinae and gluteus medius muscles during walking

The use of foot orthoses for treatment of low back pain (LBP) has received some attention in the literature, mainly from a clinical or theoretical perspective. It has been proposed that this treatment alleviates pain by altering muscle activity in the area of the low back but there is no direct evidence of such an effect. The objective of this study was to determine the effects of different types of foot wedging on the bilateral surface electromyographic activity of erector spinae (ErSp) (L3 level) and gluteus medius (GlMed) of 13 participants without LBP. Activity in ErSp had a significantly earlier onset during the gait cycle with bilateral heel lifts and bilateral lateral forefoot wedging. GlMed activity had a significantly later onset with bilateral heel lifts, and with an unilateral heel lift on the ipsilateral side (P<0.0125). No significant amplitude changes were demonstrated in either muscle for any of the forms of wedging tested. These results show that foot wedging can produce measurable changes in timing of muscle activity within the low back and pelvis during the gait cycle. Further investigation is required to determine whether this effect contributes to the alleviation of LBP.

The effect of pregnancy on footprint parameters. A prospective investigation.

Pregnancy produces significant alterations in the posture of the pregnant woman; however, gait changes that occur during pregnancy have not been adequately evaluated in the literature. This prospective investigation of the footprints of 25 pregnant women from early pregnancy to just prior to parturition revealed a significant increase in the base of gait during walking. This change in gait function may be a compensatory mechanism to improve locomotor stability, and may have important implications for foot function and development of lower-extremity pathology in pregnant women.

Ultrasound guided corticosteroid injection for plantar fasciitis: a randomised controlled trial

OBJECTIVE To investigate the effectiveness of ultrasound guided corticosteroid injection in the treatment of plantar fasciitis. DESIGN Randomised, investigator and participant blinded, placebo controlled trial. SETTING University clinic in Melbourne, Australia. PARTICIPANTS 82 people with a clinical and ultrasound diagnosis of plantar fasciitis unrelated to systemic inflammatory disease. INTERVENTIONS Participants were randomly allocated to ultrasound guided injection of the plantar fascia with either 1 mL of 4 mg/mL dexamethasone sodium phosphate (experimental group) or 1 mL normal saline (placebo). Before injection the participants were given an ultrasound guided posterior tibial nerve block with 2% lidocaine (lignocaine). MAIN OUTCOME MEASURES Primary outcomes were pain, as measured by the foot health status questionnaire (0-100 point scale), and plantar fascia thickness, measured by ultrasound at 4, 8, and 12 weeks. RESULTS Reduction in pain at four weeks favoured the dexamethasone group by 10.9 points (95% confidence interval 1.4 to 20.4, P=0.03). Between group differences for pain scores at eight and 12 weeks were not statistically significant. Plantar fascia thickness measured at four weeks favoured the dexamethasone group by -0.35 mm (95% confidence interval -0.67 to -0.03, P=0.03). At eight and 12 weeks, between group differences for plantar fascia thickness also favoured dexamethasone, at -0.39 mm (-0.73 to -0.05, P=0.02) and -0.43 mm (-0.85 to -0.01, P=0.04), respectively. The number needed to treat with dexamethasone for one successful outcome for pain at four weeks was 2.93 (95% confidence interval 2.76 to 3.12). There were no reported adverse events associated with the intervention. CONCLUSION A single ultrasound guided dexamethasone injection is a safe and effective short term treatment for plantar fasciitis. It provides greater pain relief than placebo at four weeks and reduces abnormal swelling of the plantar fascia for up to three months. However, clinicians offering this treatment should also note that significant pain relief did not continue beyond four weeks. TRIAL REGISTRATION Australian New Zealand Clinical Trials Registry ACTRN12610000239066.

Reliability of lower limb electromyography during overground walking: a comparison of maximal- and sub-maximal normalisation techniques.

The purpose of this study was to determine the reliability of investigating electromyography (EMG) of selected leg muscles during walking. Tibialis posterior and peroneus longus EMG activity were recorded via intramuscular electrodes. Tibialis anterior and medial gastrocnemius EMG activity were recorded with surface electrodes. Twenty-eight young adults attended two test-sessions approximately 15 days apart. Relative and absolute measures of reliability were calculated for EMG timing and amplitude parameters during specific phases of the gait cycle. Maximum contractions and sub-maximal contractions were obtained via maximum isometric voluntary contractions and a very fast walking speed, respectively. Time of peak EMG amplitude for all muscles displayed relatively narrow limits of random error. However, reliability of peak and root mean square amplitude parameters for tibialis posterior and peroneus longus displayed unacceptably wide limits of random error, regardless of the normalisation reference technique. Whilst some amplitude parameters for tibialis anterior and medial gastrocnemius displayed good to excellent relative reliability, the corresponding values for absolute error were generally large. Timing and amplitude EMG parameters for all muscles displayed low to moderate coefficient of variation within each test session (range: 7-25%). Overall, between-participant variability was minimised with sub-maximal normalisation values. These results demonstrate that re-application of electrodes results in large random error between sessions, particularly with tibialis posterior and peroneus longus. Researchers planning studies of these muscles with a repeated-test design (e.g. to evaluate the effect of an intervention) must consider whether this level of error is acceptable.

A comparison of augmented low-Dye taping and ankle bracing on lower limb muscle activity during walking in adults with flat-arched foot posture

OBJECTIVE To compare the effect of taping and bracing on lower limb muscle activity during gait. DESIGN Cross-sectional laboratory study. METHODS Twenty-seven asymptomatic adults with flat-arched foot posture were recruited to this study. They walked over-ground under three randomly allocated conditions: (i) barefoot; (ii) augmented low-Dye taping; (iii) replaceable ankle brace. Electromyographic (EMG) activity from tibialis posterior, tibialis anterior, peroneus longus and medial gastrocnemius was measured for each condition. Peak EMG amplitude and time of peak EMG amplitude were assessed from stance phase data. A series of one-way repeated measure analysis of variance followed by Bonferroni post hoc tests were undertaken (α=0.05). RESULTS Tibialis posterior peak EMG amplitude decreased by 22% and 33% with bracing and taping (respectively), compared to barefoot. Peak amplitude was also decreased for peroneus longus by 34% and 30% and for tibialis anterior by 19% and 13% with bracing and taping (respectively), compared to barefoot. Small significant changes in time of peak EMG amplitude were found for tibialis posterior and tibialis anterior with taping and bracing compared to barefoot. The effect of taping and bracing was only different for tibialis posterior peak EMG amplitude, with tape producing a 15% reduction compared to bracing. CONCLUSION The augmented low-Dye tape and replaceable ankle brace used in this study could be useful in managing overuse and dysfunction of selected leg muscles, particularly tibialis posterior, by reducing their level of activation during walking.

Foot posture, leg length discrepancy and low back pain - Their relationship and clinical management using foot orthoses - An overview

Mechanical low back pain (LBP) is a very common, expensive, and significant health issue in the western world. Functional musculoskeletal conditions are widely thought to cause mechanical low back pain. The role of foot posture and leg length discrepancy in contributing to abnormal biomechanics of the lumbopelvic region and low back pain is not sufficiently investigated. This critical review examines the evidence for the association between foot function, particularly pronation, and mechanical LBP. It also explores the evidence for a role for foot orthoses in the treatment of this condition. There is a body of evidence to support the notion that foot posture, particularly hyperpronation, is associated with mechanical low back pain. Mechanisms that have been put forward to account for this finding are based on either mechanical postural changes or alterations in muscular activity in the lumbar and pelvic muscles. More research is needed to explore and quantify the effects of foot orthoses on chronic low back pain, especially their effects on lumbopelvic muscle function and posture. The clinical implications of this work are significant since foot orthoses represent a simple and potentially effective therapeutic measure for a clinical condition of high personal and social burden.

Ultrasound guided injection of dexamethasone versus placebo for treatment of plantar fasciitis: protocol for a randomised controlled trial

BackgroundPlantar fasciitis is the most commonly reported cause of chronic pain beneath the heel. Management of this condition commonly involves the use of corticosteroid injection in cases where less invasive treatments have failed. However, despite widespread use, only two randomised trials have tested the effect of this treatment in comparison to placebo. These trials currently offer the best available evidence by which to guide clinical practice, though both were limited by methodological issues such as insufficient statistical power. Therefore, the aim of this randomised trial is to compare the effect of ultrasound-guided corticosteroid injection versus placebo for treatment of plantar fasciitis.MethodsThe trial will be conducted at the La Trobe University Podiatry Clinic and will recruit 80 community-dwelling participants. Diagnostic ultrasound will be used to diagnose plantar fasciitis and participants will be required to meet a range of selection criteria. Participants will be randomly allocated to one of two treatment arms: (i) ultrasound-guided injection of the plantar fascia with 1 mL of 4 mg/mL dexamethasone sodium phosphate (experimental group), or (ii) ultrasound-guided injection of the plantar fascia with 1 mL normal saline (control group). Blinding will be applied to participants and the investigator performing procedures, measuring outcomes and analysing data. Primary outcomes will be pain measured by the Foot Health Status Questionnaire and plantar fascia thickness measured by ultrasound at 4, 8 and 12 weeks. All data analyses will be conducted on an intention-to-treat basis.ConclusionThis will be a randomised trial investigating the effect of dexamethasone injection on pre-specified treatment outcomes in people with plantar fasciitis. Within the parameters of this protocol, the trial findings will be used to make evidence-based recommendations regarding the use of corticosteroid injection for treatment of this condition.Trial RegistrationAustralian New Zealand Clinical Trials Registry. ACTRN12610000239066.

The effect of different depths of medial heel skive on plantar pressures

BackgroundFoot orthoses are often used to treat lower limb injuries associated with excessive pronation. There are many orthotic modifications available for this purpose, with one being the medial heel skive. However, empirical evidence for the mechanical effects of the medial heel skive modification is limited. This study aimed to evaluate the effect that different depths of medial heel skive have on plantar pressures.MethodsThirty healthy adults (mean age 24 years, range 18–46) with a flat-arched or pronated foot posture and no current foot pain or deformity participated in this study. Using the in-shoe pedar-X® system, plantar pressure data were collected for the rearfoot, midfoot and forefoot while participants walked along an 8 metre walkway wearing a standardised shoe. Experimental conditions included a customised foot orthosis with the following 4 orthotic modifications: (i) no medial heel skive, (ii) a 2 mm medial heel skive, (iii) a 4 mm medial heel skive and (iv) a 6 mm medial heel skive.ResultsCompared to the foot orthosis with no medial heel skive, statistically significant increases in peak pressure were observed at the medial rearfoot – there was a 15% increase (p = 0.001) with the 4 mm skive and a 29% increase (p < 0.001) with the 6 mm skive. No significant change was observed with the 2 mm medial heel skive. With respect to the midfoot and forefoot, there were no significant differences between the orthoses.ConclusionsThis study found that a medial heel skive of 4 mm or 6 mm increases peak pressure under the medial rearfoot in asymptomatic adults with a flat-arched or pronated foot posture. Plantar pressures at the midfoot and forefoot were not altered by a medial heel skive of 2, 4 or 6 mm. These findings provide some evidence for the effects of the medial heel skive orthotic modification.

Teaching clinical biomechanics in the context of uncertainty.

Uncertainty in the theories that provide the underpinnings of the clinical practice of podiatric biomechanics creates a dilemma: How should educators prepare students to make clinical decisions in the context of this uncertainty? Students need to be exposed to all approaches and be given the tools to make their own clinical decisions. Critical thinking involves the ability to weigh evidence, examine arguments, and construct rational bases for decisions and beliefs. Perrys model of cognitive development provides educators with one model for fostering critical thinking skills in students to guide them through the uncertainty in clinical biomechanics. This article presents the teaching philosophy that is used to teach undergraduate clinical biomechanics in the Department of Podiatry at La Trobe University, Australia.