Patient-reported outcome measures (PROMs)

The presence of generalised foot pain is usually documented by the care provider during a physical examination , or using interviewer-administered or self-response questionnaires . Questionnaires and surveys have also been used to quantify the severity of pain and assess patients’ self-reported foot function and disability. Foot-specific outcome instruments often have subscales that evaluate pain, pain severity, activity limitation, foot function and psychosocial issues , as well as participation in sports . Two recent systematic reviews have critically evaluated surveys that are currently used: one summarised surveys used in individuals with RA and the other encompasses clinical and population-based studies . These reviews suggest that while several instruments are available, few have been studied extensively to establish their psychometric properties (e.g., Foot Function Index and Leeds Foot Impact Scale). In particular, limited evidence is available regarding responsiveness to change following non-operative and non-pharmacologic interventions. While most region-specific PROMs include both, the foot and ankle, some are specific to a region or clinical population ( Table 1 ). In clinical practice, the Lower Extremity Functional Scale (LEFS), though not foot specific, is often used, given that its reliability, construct validity and 90% confidence interval of minimal detectable change (MDC ₉₀ ) have been previously established .

Key aspects of the clinical examination

A clinical examination of the foot includes ‘traditional’ components such as history, palpation, and assessments of sensation, range of motion and strength, as well as special tests that provoke specific tissues. On observation, toe deformities and skin health (dryness, sweating and perfusion) should be noted. A detailed review of foot examination techniques and their reliability has been presented by Wrobel and Armstrong (2008) . Salient features are highlighted in subsequent paragraphs.

Static foot structure and alignment

Foot structure has been quantified in terms of the alignment of the medial longitudinal arch, as well as by characterising foot types ( Fig. 1 ). However, the predictive value of arch alignment remains contentious , and objective data quantifying the diagnostic accuracy (sensitivity, specificity, receiver operating characteristic, or ROC and curves) of arch alignment are lacking. Arch alignment has been assessed using clinical (palpation-based), radiographic and footprint-based methods that have varying levels of reliability and validity. Radiographic measures are considered the ‘gold standard’ measure of arch alignment but are susceptible to measurement errors due to magnification and beam positioning . Due to its high concurrent validity and relative ease of use, navicular height is frequently used in clinical practice . Arch height index, defined as the ratio of dorsum height to truncated foot length, can be measured using a relatively low-cost jig and offers both, high reliability and concurrent validity . Hybrid methods that combine two or more assessments of arch alignment, such as the Foot Posture Index, a six-item rating system and a screening protocol, combining clinical and radiographic methods have been proposed.

The traditional approach proposed by Root et al . focussed on identifying and correcting foot malalignment. Ideal foot alignment was defined as “subtalar neutral”, the position in which the calcaneal bisection (blue line) is parallel with the bisection of the lower third of the leg (red line), and the plane passing through all five metatarsal heads (green line) is perpendicular to the calcaneal bisection (blue line). Based on the relationship of the rearfoot and forefoot in subtalar neutral, chief malalignments include rearfoot varus and valgus (top row), forefoot varus and valgus (bottom row) are identified. Adapted from Ref. .

Aberrant foot structure such as an elevated first ray , hypermobile first ray and long second metatarsal have been linked with the development of first metatarso-phalangeal joint OA, hallux valgus and midfoot OA, respectively. Aberrant foot structure has also been linked to the development of pain and OA changes at the knee and hip ( Fig. 2 ). Gross et al. found a modest relationship between forefoot varus and ipsilateral hip pain . Limbs with low arched feet had 1.3 times the odds of knee pain . Self-reported toe out may play a significant role in the development of radiographic medial patella-femoral knee OA .

Theorized links between foot (arch alignment), knee and hip mechanics. Low arch alignment and consequent tibial internal rotation have been linked to the development of medial knee pain.

Joint range of motion

Joint range of motion, quantified using a goniometer with 1° resolution, has shown good reliability at the first metatarso-phalangeal joint and subtalar joint . The ankle is reviewed in detail in the subsequent sections. The rater should note the position used to perform testing (supine, prone or seated), method of stabilising proximal joints, and whether the measurement was obtained in the weight-bearing position, to improve consistency.

Muscle performance

Muscle strength, quantified using a hand hand-held dynamometer, has demonstrated good reliability (Intra-rater (0.78–0.94) and Inter-rater (0.77–0.88)) Intraclass Correlation Coefficient (3,1), respectively) . Standardised patient positioning and dynamometer placement are key to achieving inter-rater consistency. Decreased toe flexor strength and foot pain are independently associated with fall risk . Strength deficits have also been reported in individuals with foot pain secondary to tibialis posterior tendinopathy .

Footwear assessment

Footwear should be inspected for fit (length and width) and design features such as the presence of a heel cup, arch support, torsional and toe-break flexibility ( Fig. 3 ). Patterns of wear on the sole of the shoe and/or or scuffing should be noted. The Footwear Assessment Form is a simple and well-organised tool with established reliability and face validity . Additional work may be needed to establish its suitability across cultures and clinical populations. Individuals’ perception of footwear comfort can be assessed using the Footwear Comfort Scale .

Clinical assessment of A) torsional flexibility, B) toe break flexibility and C) wear patterns. Wear patterns assessed with the shoes on a flat surface indicate excessive lateral wear.

Dynamic assessment of foot motion (including gait analysis)

Dynamic assessment of foot function involves an observational or quantitative assessment of foot and lower extremity mechanics during a weight-bearing task (e.g., walking, running, single limb squat and step down). Dynamic assessments are particularly relevant in a clinical foot exam because evidence indicates that there is only a weak relationship between static and dynamic measures of arch height and large between-person variability . The reliability of observational assessments has been questioned by some authors , while others have found acceptable reliability using video-based gait analysis. The studies that found acceptable reliability used ordinal scales to quantify dynamic foot alignment and standardised video position and measurement procedures . Advances in three-dimensional (3D) motion capture technology have provided higher resolution and large capture volume, and afford the opportunity to simultaneously assess in vivo segmental foot motion concurrently with the motion of larger proximal joints .

Dynamic assessment of plantar load distribution

When performing a clinical assessment, the plantar aspect of the foot should be inspected for patterns of calluses and weight bearing. More recently, load distribution (plantar pressure) at the foot-floor or the foot–shoe interface has been quantified during functional activities such as walking, stair ascent and descent and running . The reliability of both, barefoot as well as in-shoe pressure measuring devices, has been established . Early applications of this technology focussed on individuals with diabetes and neuropathy who demonstrate loss of protective sensation. The evaluation of the at-risk diabetic foot is covered in an excellent review , and thus, will not be described in this paper. More recently, in individuals with foot pain, and elevated and prolonged plantar loading has been postulated to contribute to the evolution of patients’ self-reported pain. Consistent with this mechanical overloading theory, recent reports have found increased regional plantar pressure accompanying foot pain . By contrast, some authors postulate that individuals experiencing foot pain adopt an antalgic strategy to avoid exacerbating their foot pain. For instance, individuals with first metatarso-phalangeal OA may shift their weight laterally in an attempt to unload the painful region during walking . Similarly, lower lateral forefoot loading has been reported in patients with RA and low Health Assessment Questionnaire (HAQ) score (more disability and more pain) compared to RA patients with high HAQ scores . While pressure measurement technology and appropriate measurement methods are increasingly common in clinical and population-based research studies, their use in routine clinical practice is infrequent.

Provocational tests

The final part of the clinical examination comprises provocational tests that provoke specific tissues. The Windlass test ( Fig. 4 ) is used to stretch the plantar fascia and is considered positive if the patient reports pain when the first metatarso-phalangeal joint is passively dorsiflexed . Limited extensibility in the gastrocnemius–soleus complex or the flexor hallucis longus can be assessed using passive muscle length testing. Symptoms related to the sesamoids may manifest as plantar pain and localised tenderness to palpation. Custom devices have been developed to objectively quantify first ray dorsal mobility and first metatarso-phalangeal joint mobility in in vivo research studies; however, these devices are not in widespread use in clinical practice.

Flexor Hallucis Longus tightness. First, the interphalangeal joint extended and dorsiflexion of the 1st metatarsophalangeal joint is measured. Next, the interphalangeal joint is flexed and dorsiflexion of the 1st metatarsophalangeal joint is measured. If the latter is greater than the former, tightness of the Flexor Hallucis Longus muscle may present. Dorsiflexion of the 1st metatarsophalangeal joint may also stretch the plantar fascia in which case pain is reported in the middle the heel (Windlass test).

Overview and general approach

The primary aim of treatment is to afford pain relief, restore mechanics (alignment, motion and/or load distribution) and return the patient to their desired level of activity participation. The plan of care should be designed with the goal of targeting impairments noted during assessment. The most frequently used treatment modalities in this clinical population include orthoses and footwear, stretching and therapeutic exercises, manual therapy, taping and combinational therapies, and are discussed in detail in subsequent subsections.

Orthoses and footwear

Over the last decade, significant evolution has occurred in clinical decision making related to the prescription of foot orthoses. Three theoretical approaches can be distinguished. The traditional approach proposed by Root et al. focussed on identifying impairments in foot alignment and used orthoses to restore static and dynamic foot alignment. Subtalar neutral position, operationally defined as the position in which the calcaneal bisection is parallel with the bisection of the lower third of the leg, and the plane passing through all five metatarsal heads perpendicular to the calcaneal bisection, was considered ideal foot alignment . Based on the relationship of the rearfoot and forefoot in subtalar neutral, four chief malalignments were delineated (rearfoot varus, rearfoot valgus, forefoot varus and forefoot valgus ( Fig. 1 ). While Root et al. ‘s approach had a substantial influence on orthoses prescription, increasing concerns emerged related to its reliability and validity. Studies examining the inter-rater reliability of clinicians in positioning the foot in subtalar neutral have reported measurement errors of 4°, with better reliability reported in weight-bearing measures . Measurement error is extremely important because it can lead to errors in classification of foot malalignment. Questions have been raised related to the validity of Root et al. ‘s classification system, and limited normative data are available. For example, one study found forefoot valgus in 45% limbs assessed in women (mean age: 23 years) , while another group found forefoot varus in 87% limbs assessed in women (mean age: 28 years) . Lastly, while Root et al. postulated that static foot alignment and dynamic foot function are strongly linked, objective evidence has challenged the predictive value of static alignment. In asymptomatic adults, root-based static foot alignment was not significantly related to dynamic foot motion .

As an alternative, the Tissue Stress Model has been proposed as a paradigm to guide the evaluation and management of foot disorders . This model is based on an individual-specific load deformation curve and postulates that deformation within the elastic region of the curve will not provoke symptoms. However, tissue stress in the micro-failure or plastic region of the load deformation curve may result in injury and inflammation. Consequently, tissue-specific interventions incorporating orthoses, and stretching and targeted exercises have been proposed in individuals with foot pain. Similarly, the Preferred Movement Pathway theory proposes that orthoses do not function by realigning the skeleton but rather by altering input signals (forces) acting on the foot during the stance phase and resultant muscle activation . Additional evidence is needed to establish the use of these theoretical models in clinical decision making.

Orthoses and footwear have been postulated to relieve foot pain by restoring alignment , redistributing plantar loads or limiting motion and ‘splinting’ the painful joints . In individuals with midfoot pain, footwear modifications such as steel shanked shoes and rocker shoes are prescribed to limit motion at the painful joints . However, these modifications are often cosmetically unacceptable, resulting in poor compliance with therapeutic footwear. As an alternative, low profile and stiff carbon graphite orthoses have been used in this population more recently . In individuals with tibialis posterior tendinopathy, braces incorporating design features (e.g., air bladder) that allow subject-specific correction of aberrant foot motion are available. Objective data suggest that while braces have a robust effect on correcting hindfoot eversion in individuals with tibialis posterior tendinopathy, their effect in controlling forefoot abduction may be variable .

A recent systematic review indicates that custom foot orthoses should be used judiciously in the treatment of foot pain . Yet, custom-made foot orthoses were effective for painful pes cavus and rearfoot pain in RA (studies show a remarkably small number needed to treat only 4–5 patients for either of these specific conditions to show a benefit). Custom orthoses were as effective as over-the-counter orthoses in juvenile idiopathic arthritis, and surgery was more effective than custom orthoses in painful hallux valgus . There is no evidence to support the use of custom orthoses in plantar heel pain . While the use of custom orthoses has been accompanied by very few side effects, they can be expensive ($300–700 per pair) and their efficacy can be variable. Some authors have suggested the use of a treatment direction test to predict determine whether orthoses will be successful in providing pain relief . Briefly, the patient’s history and physical examination are used to identify specific tasks that provoke symptoms. Taping is applied (low-dye taping, with felt pads, if needed), and if the patient reports greater than 50% resolution of symptoms, orthoses are prescribed. If the patient reports modest symptomatic relief with taping, orthoses are unlikely to be effective.

Taping

In individuals with plantar heel pain (plantar fasciitis), low-dye taping has been used to provide short-term pain relief. In a recent clinical trial, week-long application of low-dye taping produced a small but significant reduction in ‘first-step’ pain compared with sham ultrasound . This trial also noted that 28% of patients treated with taping reported mild to moderate adverse effects such as discomfort from the tape being too tight, emergence of a new pain or an allergic reaction. Adverse reactions may limit compliance with taping. More recently, taping has been used to determine if the patient is a candidate for custom orthoses (see Treatment Direction Test in the section on Orthoses and Footwear above).

Stretching

Stretching is a key component of rehabilitation interventions for foot pain, particularly in individuals with heel pain. Stretching protocols in heel pain involve weight-bearing and non-weight-bearing calf stretches and a plantar fascia stretch performed with the patient seated. The patient is instructed to perform at least 10 repetitions of each stretch, with a 10–20 s hold, at least twice a day . In a recent clinical trial, tissue-specific plantar fascia stretching demonstrated superior pain relief and improvement self-reported outcomes at 8-week follow-up compared to calf stretching .

Therapeutic exercise

Targeted as well as generalised strength training have been prescribed for individuals with foot pain, and have been associated with positive outcomes. In individuals with tibialis posterior tendinopathy, participation in a structured, 10–12-week eccentric strengthening programme was associated with symptomatic relief and improvement in physical function . In a recent clinical trial, a home-based programme of foot and ankle exercises combined with routine foot care demonstrated a 36% reduction in falls rate in community-dwelling older adults . In addition to exercises, this community-based intervention included orthoses, advice on and subsidy for footwear, a falls prevention education booklet, and routine foot care for 12 months. Additional examples of stretching and therapeutic exercises are presented in the section on Combinational Therapy below.

Manual therapy

Manual therapy includes soft-tissue techniques (such as trigger point release and strain counterstrain) and joint mobilisations to address restrictions at the foot (subtalar, talo-crural and inter-tarsal joints) as well as proximal joints (hip, knee and ankle) . Promising recent studies indicate that soft-tissue mobilisation may provide short-term pain relief in individuals with heel pain. The addition of myofascial trigger point release to a self-stretching protocol provided superior short-term (single session) pain relief compared to a self-stretching protocol . Studies using joint mobilisations in conjunction with other modalities are covered in the section on Combinational Therapy below.

Combinational therapy

Consistent with the concept of functional phenotypes (sub-groups) of foot pain that are characterised by the existence of multiple impairments (e.g., pain, loss of range of motion and poor muscle performance), a number of recent studies have proposed combinational therapies to alleviate pain and maximise return to activity participation. For instance, in individuals with first metatarso-phalangeal joint pain, the addition of sesamoid mobilisation, flexor hallucis strengthening and gait training resulted in superior pain relief, restoration of range of motion and strength, compared to a control group that received physical modalities (whirlpool, ultrasound, cold packs and electrical stimulation) and general lower extremity exercises (calf and hamstring stretching and marble pick-up exercise) . Similarly, individuals with heel pain treated with combinational therapy including joint mobilisations and stretching demonstrated superior pain relief and self-reported physical function at a 4-week follow-up compared to those treated with electro physical agents (ultrasound and ionophoresis) and stretching .

Individuals with RA are particularly susceptible to foot pain, deformities and disability. Consequently, aggressive preventive and monitoring strategies have been deployed in this population. In parallel with tight disease control through medical management, early detection of forefoot pain, and diagnostic ultrasonography and corticosteroid injection therapies for localised synovitis are strongly advocated . In a recent systematic review of the role of orthoses in RA, the use of rigid, full-length custom-moulded orthoses was accompanied by pain relief and reduction in forefoot plantar loading . In addition to foot-specific interventions, rehabilitation interventions including elements of physical activity, strength training and self-management are critical to maintaining physical health and wellness in individuals with RA . While high-quality evidence in the form of clinical trials is relatively scarce, two recent reviews have summarised key features of rehabilitation interventions that are beneficial in the management of individuals with RA . These reviews indicate that while the benefits of physical activity programmes in improving outcomes in individuals with RA are well established, limited objective data are available examining the effects of dosage and intensity. Critical aspects of successful programmes include access to multidisciplinary care, and the use of cognitive behavioural approaches, therapeutic exercise and joint protection strategies.

In summary, the management of foot pain has grown to include combinational therapies that address multiple foot-specific impairments as well as maintain physical health. While robust evidence supports the use of custom-moulded orthoses in individuals with RA, there is limited support for the use of custom devices in plantar heel pain or midfoot pain. Additional studies are needed to assess if non-pharmacologic interventions such as taping and soft-tissue mobilisation provide long-term pain relief. There is a need for community-based and self-management interventions in individuals with foot pain.

Patient-reported outcome measures (PROMs)

The presence of generalised foot pain is usually documented by the care provider during a physical examination , or using interviewer-administered or self-response questionnaires . Questionnaires and surveys have also been used to quantify the severity of pain and assess patients’ self-reported foot function and disability. Foot-specific outcome instruments often have subscales that evaluate pain, pain severity, activity limitation, foot function and psychosocial issues , as well as participation in sports . Two recent systematic reviews have critically evaluated surveys that are currently used: one summarised surveys used in individuals with RA and the other encompasses clinical and population-based studies . These reviews suggest that while several instruments are available, few have been studied extensively to establish their psychometric properties (e.g., Foot Function Index and Leeds Foot Impact Scale). In particular, limited evidence is available regarding responsiveness to change following non-operative and non-pharmacologic interventions. While most region-specific PROMs include both, the foot and ankle, some are specific to a region or clinical population ( Table 1 ). In clinical practice, the Lower Extremity Functional Scale (LEFS), though not foot specific, is often used, given that its reliability, construct validity and 90% confidence interval of minimal detectable change (MDC ₉₀ ) have been previously established .

Key aspects of the clinical examination

A clinical examination of the foot includes ‘traditional’ components such as history, palpation, and assessments of sensation, range of motion and strength, as well as special tests that provoke specific tissues. On observation, toe deformities and skin health (dryness, sweating and perfusion) should be noted. A detailed review of foot examination techniques and their reliability has been presented by Wrobel and Armstrong (2008) . Salient features are highlighted in subsequent paragraphs.

Static foot structure and alignment

Foot structure has been quantified in terms of the alignment of the medial longitudinal arch, as well as by characterising foot types ( Fig. 1 ). However, the predictive value of arch alignment remains contentious , and objective data quantifying the diagnostic accuracy (sensitivity, specificity, receiver operating characteristic, or ROC and curves) of arch alignment are lacking. Arch alignment has been assessed using clinical (palpation-based), radiographic and footprint-based methods that have varying levels of reliability and validity. Radiographic measures are considered the ‘gold standard’ measure of arch alignment but are susceptible to measurement errors due to magnification and beam positioning . Due to its high concurrent validity and relative ease of use, navicular height is frequently used in clinical practice . Arch height index, defined as the ratio of dorsum height to truncated foot length, can be measured using a relatively low-cost jig and offers both, high reliability and concurrent validity . Hybrid methods that combine two or more assessments of arch alignment, such as the Foot Posture Index, a six-item rating system and a screening protocol, combining clinical and radiographic methods have been proposed.

The traditional approach proposed by Root et al . focussed on identifying and correcting foot malalignment. Ideal foot alignment was defined as “subtalar neutral”, the position in which the calcaneal bisection (blue line) is parallel with the bisection of the lower third of the leg (red line), and the plane passing through all five metatarsal heads (green line) is perpendicular to the calcaneal bisection (blue line). Based on the relationship of the rearfoot and forefoot in subtalar neutral, chief malalignments include rearfoot varus and valgus (top row), forefoot varus and valgus (bottom row) are identified. Adapted from Ref. .

Aberrant foot structure such as an elevated first ray , hypermobile first ray and long second metatarsal have been linked with the development of first metatarso-phalangeal joint OA, hallux valgus and midfoot OA, respectively. Aberrant foot structure has also been linked to the development of pain and OA changes at the knee and hip ( Fig. 2 ). Gross et al. found a modest relationship between forefoot varus and ipsilateral hip pain . Limbs with low arched feet had 1.3 times the odds of knee pain . Self-reported toe out may play a significant role in the development of radiographic medial patella-femoral knee OA .

Theorized links between foot (arch alignment), knee and hip mechanics. Low arch alignment and consequent tibial internal rotation have been linked to the development of medial knee pain.

Joint range of motion

Joint range of motion, quantified using a goniometer with 1° resolution, has shown good reliability at the first metatarso-phalangeal joint and subtalar joint . The ankle is reviewed in detail in the subsequent sections. The rater should note the position used to perform testing (supine, prone or seated), method of stabilising proximal joints, and whether the measurement was obtained in the weight-bearing position, to improve consistency.

Muscle performance

Muscle strength, quantified using a hand hand-held dynamometer, has demonstrated good reliability (Intra-rater (0.78–0.94) and Inter-rater (0.77–0.88)) Intraclass Correlation Coefficient (3,1), respectively) . Standardised patient positioning and dynamometer placement are key to achieving inter-rater consistency. Decreased toe flexor strength and foot pain are independently associated with fall risk . Strength deficits have also been reported in individuals with foot pain secondary to tibialis posterior tendinopathy .

Footwear assessment

Footwear should be inspected for fit (length and width) and design features such as the presence of a heel cup, arch support, torsional and toe-break flexibility ( Fig. 3 ). Patterns of wear on the sole of the shoe and/or or scuffing should be noted. The Footwear Assessment Form is a simple and well-organised tool with established reliability and face validity . Additional work may be needed to establish its suitability across cultures and clinical populations. Individuals’ perception of footwear comfort can be assessed using the Footwear Comfort Scale .

Clinical assessment of A) torsional flexibility, B) toe break flexibility and C) wear patterns. Wear patterns assessed with the shoes on a flat surface indicate excessive lateral wear.

Dynamic assessment of foot motion (including gait analysis)

Dynamic assessment of foot function involves an observational or quantitative assessment of foot and lower extremity mechanics during a weight-bearing task (e.g., walking, running, single limb squat and step down). Dynamic assessments are particularly relevant in a clinical foot exam because evidence indicates that there is only a weak relationship between static and dynamic measures of arch height and large between-person variability . The reliability of observational assessments has been questioned by some authors , while others have found acceptable reliability using video-based gait analysis. The studies that found acceptable reliability used ordinal scales to quantify dynamic foot alignment and standardised video position and measurement procedures . Advances in three-dimensional (3D) motion capture technology have provided higher resolution and large capture volume, and afford the opportunity to simultaneously assess in vivo segmental foot motion concurrently with the motion of larger proximal joints .

Dynamic assessment of plantar load distribution

When performing a clinical assessment, the plantar aspect of the foot should be inspected for patterns of calluses and weight bearing. More recently, load distribution (plantar pressure) at the foot-floor or the foot–shoe interface has been quantified during functional activities such as walking, stair ascent and descent and running . The reliability of both, barefoot as well as in-shoe pressure measuring devices, has been established . Early applications of this technology focussed on individuals with diabetes and neuropathy who demonstrate loss of protective sensation. The evaluation of the at-risk diabetic foot is covered in an excellent review , and thus, will not be described in this paper. More recently, in individuals with foot pain, and elevated and prolonged plantar loading has been postulated to contribute to the evolution of patients’ self-reported pain. Consistent with this mechanical overloading theory, recent reports have found increased regional plantar pressure accompanying foot pain . By contrast, some authors postulate that individuals experiencing foot pain adopt an antalgic strategy to avoid exacerbating their foot pain. For instance, individuals with first metatarso-phalangeal OA may shift their weight laterally in an attempt to unload the painful region during walking . Similarly, lower lateral forefoot loading has been reported in patients with RA and low Health Assessment Questionnaire (HAQ) score (more disability and more pain) compared to RA patients with high HAQ scores . While pressure measurement technology and appropriate measurement methods are increasingly common in clinical and population-based research studies, their use in routine clinical practice is infrequent.

Provocational tests

The final part of the clinical examination comprises provocational tests that provoke specific tissues. The Windlass test ( Fig. 4 ) is used to stretch the plantar fascia and is considered positive if the patient reports pain when the first metatarso-phalangeal joint is passively dorsiflexed . Limited extensibility in the gastrocnemius–soleus complex or the flexor hallucis longus can be assessed using passive muscle length testing. Symptoms related to the sesamoids may manifest as plantar pain and localised tenderness to palpation. Custom devices have been developed to objectively quantify first ray dorsal mobility and first metatarso-phalangeal joint mobility in in vivo research studies; however, these devices are not in widespread use in clinical practice.

Flexor Hallucis Longus tightness. First, the interphalangeal joint extended and dorsiflexion of the 1st metatarsophalangeal joint is measured. Next, the interphalangeal joint is flexed and dorsiflexion of the 1st metatarsophalangeal joint is measured. If the latter is greater than the former, tightness of the Flexor Hallucis Longus muscle may present. Dorsiflexion of the 1st metatarsophalangeal joint may also stretch the plantar fascia in which case pain is reported in the middle the heel (Windlass test).

Overview and general approach

The primary aim of treatment is to afford pain relief, restore mechanics (alignment, motion and/or load distribution) and return the patient to their desired level of activity participation. The plan of care should be designed with the goal of targeting impairments noted during assessment. The most frequently used treatment modalities in this clinical population include orthoses and footwear, stretching and therapeutic exercises, manual therapy, taping and combinational therapies, and are discussed in detail in subsequent subsections.

Orthoses and footwear

Over the last decade, significant evolution has occurred in clinical decision making related to the prescription of foot orthoses. Three theoretical approaches can be distinguished. The traditional approach proposed by Root et al. focussed on identifying impairments in foot alignment and used orthoses to restore static and dynamic foot alignment. Subtalar neutral position, operationally defined as the position in which the calcaneal bisection is parallel with the bisection of the lower third of the leg, and the plane passing through all five metatarsal heads perpendicular to the calcaneal bisection, was considered ideal foot alignment . Based on the relationship of the rearfoot and forefoot in subtalar neutral, four chief malalignments were delineated (rearfoot varus, rearfoot valgus, forefoot varus and forefoot valgus ( Fig. 1 ). While Root et al. ‘s approach had a substantial influence on orthoses prescription, increasing concerns emerged related to its reliability and validity. Studies examining the inter-rater reliability of clinicians in positioning the foot in subtalar neutral have reported measurement errors of 4°, with better reliability reported in weight-bearing measures . Measurement error is extremely important because it can lead to errors in classification of foot malalignment. Questions have been raised related to the validity of Root et al. ‘s classification system, and limited normative data are available. For example, one study found forefoot valgus in 45% limbs assessed in women (mean age: 23 years) , while another group found forefoot varus in 87% limbs assessed in women (mean age: 28 years) . Lastly, while Root et al. postulated that static foot alignment and dynamic foot function are strongly linked, objective evidence has challenged the predictive value of static alignment. In asymptomatic adults, root-based static foot alignment was not significantly related to dynamic foot motion .

As an alternative, the Tissue Stress Model has been proposed as a paradigm to guide the evaluation and management of foot disorders . This model is based on an individual-specific load deformation curve and postulates that deformation within the elastic region of the curve will not provoke symptoms. However, tissue stress in the micro-failure or plastic region of the load deformation curve may result in injury and inflammation. Consequently, tissue-specific interventions incorporating orthoses, and stretching and targeted exercises have been proposed in individuals with foot pain. Similarly, the Preferred Movement Pathway theory proposes that orthoses do not function by realigning the skeleton but rather by altering input signals (forces) acting on the foot during the stance phase and resultant muscle activation . Additional evidence is needed to establish the use of these theoretical models in clinical decision making.

Orthoses and footwear have been postulated to relieve foot pain by restoring alignment , redistributing plantar loads or limiting motion and ‘splinting’ the painful joints . In individuals with midfoot pain, footwear modifications such as steel shanked shoes and rocker shoes are prescribed to limit motion at the painful joints . However, these modifications are often cosmetically unacceptable, resulting in poor compliance with therapeutic footwear. As an alternative, low profile and stiff carbon graphite orthoses have been used in this population more recently . In individuals with tibialis posterior tendinopathy, braces incorporating design features (e.g., air bladder) that allow subject-specific correction of aberrant foot motion are available. Objective data suggest that while braces have a robust effect on correcting hindfoot eversion in individuals with tibialis posterior tendinopathy, their effect in controlling forefoot abduction may be variable .

A recent systematic review indicates that custom foot orthoses should be used judiciously in the treatment of foot pain . Yet, custom-made foot orthoses were effective for painful pes cavus and rearfoot pain in RA (studies show a remarkably small number needed to treat only 4–5 patients for either of these specific conditions to show a benefit). Custom orthoses were as effective as over-the-counter orthoses in juvenile idiopathic arthritis, and surgery was more effective than custom orthoses in painful hallux valgus . There is no evidence to support the use of custom orthoses in plantar heel pain . While the use of custom orthoses has been accompanied by very few side effects, they can be expensive ($300–700 per pair) and their efficacy can be variable. Some authors have suggested the use of a treatment direction test to predict determine whether orthoses will be successful in providing pain relief . Briefly, the patient’s history and physical examination are used to identify specific tasks that provoke symptoms. Taping is applied (low-dye taping, with felt pads, if needed), and if the patient reports greater than 50% resolution of symptoms, orthoses are prescribed. If the patient reports modest symptomatic relief with taping, orthoses are unlikely to be effective.

Taping

In individuals with plantar heel pain (plantar fasciitis), low-dye taping has been used to provide short-term pain relief. In a recent clinical trial, week-long application of low-dye taping produced a small but significant reduction in ‘first-step’ pain compared with sham ultrasound . This trial also noted that 28% of patients treated with taping reported mild to moderate adverse effects such as discomfort from the tape being too tight, emergence of a new pain or an allergic reaction. Adverse reactions may limit compliance with taping. More recently, taping has been used to determine if the patient is a candidate for custom orthoses (see Treatment Direction Test in the section on Orthoses and Footwear above).

Stretching

Stretching is a key component of rehabilitation interventions for foot pain, particularly in individuals with heel pain. Stretching protocols in heel pain involve weight-bearing and non-weight-bearing calf stretches and a plantar fascia stretch performed with the patient seated. The patient is instructed to perform at least 10 repetitions of each stretch, with a 10–20 s hold, at least twice a day . In a recent clinical trial, tissue-specific plantar fascia stretching demonstrated superior pain relief and improvement self-reported outcomes at 8-week follow-up compared to calf stretching .

Therapeutic exercise

Targeted as well as generalised strength training have been prescribed for individuals with foot pain, and have been associated with positive outcomes. In individuals with tibialis posterior tendinopathy, participation in a structured, 10–12-week eccentric strengthening programme was associated with symptomatic relief and improvement in physical function . In a recent clinical trial, a home-based programme of foot and ankle exercises combined with routine foot care demonstrated a 36% reduction in falls rate in community-dwelling older adults . In addition to exercises, this community-based intervention included orthoses, advice on and subsidy for footwear, a falls prevention education booklet, and routine foot care for 12 months. Additional examples of stretching and therapeutic exercises are presented in the section on Combinational Therapy below.

Manual therapy

Manual therapy includes soft-tissue techniques (such as trigger point release and strain counterstrain) and joint mobilisations to address restrictions at the foot (subtalar, talo-crural and inter-tarsal joints) as well as proximal joints (hip, knee and ankle) . Promising recent studies indicate that soft-tissue mobilisation may provide short-term pain relief in individuals with heel pain. The addition of myofascial trigger point release to a self-stretching protocol provided superior short-term (single session) pain relief compared to a self-stretching protocol . Studies using joint mobilisations in conjunction with other modalities are covered in the section on Combinational Therapy below.

Combinational therapy

Consistent with the concept of functional phenotypes (sub-groups) of foot pain that are characterised by the existence of multiple impairments (e.g., pain, loss of range of motion and poor muscle performance), a number of recent studies have proposed combinational therapies to alleviate pain and maximise return to activity participation. For instance, in individuals with first metatarso-phalangeal joint pain, the addition of sesamoid mobilisation, flexor hallucis strengthening and gait training resulted in superior pain relief, restoration of range of motion and strength, compared to a control group that received physical modalities (whirlpool, ultrasound, cold packs and electrical stimulation) and general lower extremity exercises (calf and hamstring stretching and marble pick-up exercise) . Similarly, individuals with heel pain treated with combinational therapy including joint mobilisations and stretching demonstrated superior pain relief and self-reported physical function at a 4-week follow-up compared to those treated with electro physical agents (ultrasound and ionophoresis) and stretching .

Individuals with RA are particularly susceptible to foot pain, deformities and disability. Consequently, aggressive preventive and monitoring strategies have been deployed in this population. In parallel with tight disease control through medical management, early detection of forefoot pain, and diagnostic ultrasonography and corticosteroid injection therapies for localised synovitis are strongly advocated . In a recent systematic review of the role of orthoses in RA, the use of rigid, full-length custom-moulded orthoses was accompanied by pain relief and reduction in forefoot plantar loading . In addition to foot-specific interventions, rehabilitation interventions including elements of physical activity, strength training and self-management are critical to maintaining physical health and wellness in individuals with RA . While high-quality evidence in the form of clinical trials is relatively scarce, two recent reviews have summarised key features of rehabilitation interventions that are beneficial in the management of individuals with RA . These reviews indicate that while the benefits of physical activity programmes in improving outcomes in individuals with RA are well established, limited objective data are available examining the effects of dosage and intensity. Critical aspects of successful programmes include access to multidisciplinary care, and the use of cognitive behavioural approaches, therapeutic exercise and joint protection strategies.

In summary, the management of foot pain has grown to include combinational therapies that address multiple foot-specific impairments as well as maintain physical health. While robust evidence supports the use of custom-moulded orthoses in individuals with RA, there is limited support for the use of custom devices in plantar heel pain or midfoot pain. Additional studies are needed to assess if non-pharmacologic interventions such as taping and soft-tissue mobilisation provide long-term pain relief. There is a need for community-based and self-management interventions in individuals with foot pain.