Clinicians' assessment of the hindfoot: a study of reliability

Modified hindfoot alignment radiological evaluation and application in the assessment of flatfoot

BACKGROUND

Alignment is indispensable for the foot and ankle function, especially in the hindfoot alignment. In the preoperative planning of patients with varus or valgus deformity, the precise measurement of the hindfoot alignment is important. A new method of photographing and measuring hindfoot alignment based on X-ray was proposed in this study, and it was applied in the assessment of flatfoot.

METHODS

This study included 28 patients (40 feet) with flatfeet and 20 volunteers (40 feet) from January to December 2018. The hindfoot alignment shooting stand independently designed by our department was used to take hindfoot alignment X-rays at 10 degree, 15 degree, 20 degree, 25 degree, and 30 degree. We measured the modified tibio-hindfoot angle (THA) at the standard hindfoot aligment position (shooting at 20 degree) and evaluated consistency with the van Dijk method and the modified van Dijk method. In addition, we observed the visibility of the tibiotalar joint space from all imaging data at five projection angles and evaluated the consistency of the modified THA method at different projection angles. The angle of hindfoot valgus of flatfoot patients was measured using the modified THA method.

RESULTS

The mean THA in the standard hindfoot aligment view in normal people was significantly different among the three evaluation methods (P < .001). The results from the modified THA method were significantly larger than those from the Van Dijk method (P < .001) and modified Van Dijk method (P < .001). There was no significant difference between the results of the modified THA method and the weightbearing CT (P = .605), and the intra- and intergroup consistency were the highest in the modified THA group. The tibiotalar space in the normal group was visible in all cases at 10 degree, 15 degree, and 20 degree; visible in some cases at 25 degree; and not visible in all cases at 30 degree. In the flatfoot group, the tibiotalar space was visible in all cases at 10 degree, visible in some cases at 15 degree and 20 degree, and not visible in all cases at 25 degree and 30 degree. In the normal group, the modified THA was 4.84 ± 1.81 degree at 10 degree, 4.96 ± 1.77 degree at 15 degree, and 4.94 ± 2.04 degree at 20 degree. No significant differences were found among the three groups (P = .616). In the flatfoot group, the modified THA of 18 feet, which was visible at 10 degree, 15 degree and 20 degree, was 13.58 ± 3.57 degree at 10 degree, 13.62 ± 3.83 degree at 15 degree and 13.38 ± 4.06 degree at 20 degree. There were no significant differences among the three groups (P = .425).

CONCLUSIONS

The modified THA evaluation method is simple to use and has high inter- and intragroup consistency. It can be used to evaluate hindfoot alignment. For patients with flatfeet, the 10 degree position view and modified THA measurement can be used to evaluate hindfoot valgus.

Assessment of Aircraft Engine Blade Inspection Performance Using Attribute Agreement Analysis

Background—Visual inspection is an important element of aircraft engine maintenance to assure flight safety. Predominantly performed by human operators, those maintenance activities are prone to human error. While false negatives imply a risk to aviation safety, false positives can lead to increased maintenance cost. The aim of the present study was to evaluate the human performance in visual inspection of aero engine blades, specifically the operators’ consistency, accuracy, and reproducibility, as well as the system reliability. Methods—Photographs of 26 blades were presented to 50 industry practitioners of three skill levels to assess their performance. Each image was shown to each operator twice in random order, leading to N = 2600 observations. The data were statistically analysed using Attribute Agreement Analysis (AAA) and Kappa analysis. Results—The results show that operators were on average 82.5% consistent with their serviceability decision, while achieving an inspection accuracy of 67.7%. The operators’ reproducibility was 15.4%, as was the accuracy of all operators with the ground truth. Subsequently, the false-positive and false-negative rates were analysed separately to the overall inspection accuracy, showing that 20 operators (40%) achieved acceptable performances, thus meeting the required standard. Conclusions—In aviation maintenance the false-negative rate of <5% as per Aerospace Standard AS13100 is arguably the single most important metric since it determines the safety outcomes. The results of this study show acceptable false-negative performance in 60% of appraisers. Thus, there is the desirability to seek ways to improve the performance. Some suggestions are given in this regard.

A Narrative Review on the Tests Used in Biomechanical Functional Assessment of the Foot and Leg: Diagnostic Tests of Deformities and Compensations

BACKGROUND

To date, scientific literature has not as yet come up with any review showing the diagnostic tests used for functional assessment of the foot and leg.

METHODS

A literature review was conducted of electronic databases (MEDLINE, PEDro, DOAJ, BioMed Central, PLOS, and Centre for Reviews and Dissemination at the University of York) up to December 8, 2018. The biomechanical tests, which have adequate supportive literature, were divided into qualitative tests that provide a dichotomy/trichotomy-type answer to clinical diagnostic questions; semiquantitative tests that provide numerical data to clinical diagnostic questions; and quantitative tests that record continuous numerical data (in analogue or digital form).

RESULTS

These tests produce a useful functional evaluation model of the foot and leg for different purposes: evaluation of lower limb deficits or abnormalities in healthy patients and in athletes (in sports or other physical activities); assessment of tissue stress syndromes caused by pathomechanics; evaluation of lower limb deficits or abnormalities in rheumatic disease and diabetic foot patients; and to determine the appropriate functional or semifunctional foot orthotic therapy and therapeutic path used in gait rehabilitation.

CONCLUSIONS

Many of these tests have adequate diagnostic reliability and reproducibility and therefore can be considered diagnostic. Few of these are validated, and some have initiated the validation process by determining their sensitivity and specificity. The widespread use of these tools in clinical practice (diagnosis of function) lacks scientific evidence and in-depth analysis of their limitations.

The relationship between measures of foot mobility and subtalar joint stiffness using vibration energy with color Doppler imaging-A clinical proof-of-concept validation study

INTRODUCTION

Subtalar joint (STJ) dysfunction can contribute to movement disturbances. Vibration energy with color Doppler imaging (VECDI) may be useful for detecting STJ stiffness changes.

OBJECTIVES

(1) Support proof-of-concept that VECDI could detect STJ stiffness differences; (2) Establish STJ stiffness range in asymptomatic volunteers; (3) Examine relationships between STJ stiffness and foot mobility; and (4) Assess VECDI precision and reliability for examining STJ stiffness.

METHODS

After establishing cadaveric testing model proof-of-concept, STJ stiffness (threshold units, ΔTU), ankle complex passive range-of-motion (PROM) and midfoot-width-difference (MFWDiff) data were collected in 28 asymptomatic subjects in vivo. Three reliability measurements were collected per variable; Rater-1 collected on all subjects and rater-2 on the first ten subjects. Subjects were classified into three STJ stiffness groups.

RESULTS

Cadaveric VECDI measurement intra-rater reliability was 0.80. A significantly lower STJ ΔTU (p = .002) and ankle complex PROM (p < .001) was observed during the screw fixation versus normal condition. A fair correlation (r = 0.660) was observed between cadaveric ΔTU and ankle complex PROM. In vivo VECDI measurements demonstrated good intra-rater (0.76-0.84) versus poor inter-rater (-3.11) reliability. Significant positive correlations were found between STJ stiffness and both dorsum (r = .440) and posterior (r = .390) PROM. MFWDiff exhibited poor relationships with stiffness (r = .103) and either dorsum (r = .256) or posterior (r = .301) PROM. STJ stiffness ranged from 2.33 to 7.50 ΔTUs, categorizing subjects' STJ stiffness as increased (n = 6), normal (n = 15), or decreased (n = 7). Significant ANOVA main effects for classification were found based on ΔTU (p< .001), dorsum PROM (p = .017), and posterior PROM (p = .036). Post-hoc tests revealed significant: (1) ΔTU differences between all stiffness groups (p < .001); (2) dorsum PROM differences between the increased versus normal (p = .044) and decreased (p = .017) stiffness groups; and (3) posterior PROM differences between the increased versus decreased stiffness groups (p = .044). A good relationship was found between STJ stiffness and dorsum PROM in the increased stiffness group (r = .853) versus poor, nonsignificant relationships in the normal (r = -.042) or decreased stiffness (r = -.014) groups.

CONCLUSION

PROM may not clinically explain all aspects of joint mobility. Joint VECDI stiffness assessment should be considered as a complimentary measurement technique.

Foot and ankle abnormalities among a cohort of Nigerian school children: an epidemiological study

PURPOSE

Foot and ankle problems in children are a common cause for paediatric orthopaedic referrals. There is a variation in the reported epidemiology of foot and ankle abnormalities across the globe. The prevalence in our locality was unknown. The objective of this study was to determine the prevalence pattern of foot and ankle problems in our locality as well as compare with patterns from other geographical locations to determine the presence or otherwise, of differences among varying populations.

METHODS

One thousand seven hundred and fifty-eight Nigerian primary school children aged between five and 13 years were clinically evaluated, checking for weight, height and calculation of BMI. The heel axis angle and hallux angle were measured clinically while determination of flatfeet or high arched feet was made from analysis of foot imprints.

RESULTS

Hindfoot valgus was the commonest abnormality of the foot and ankle in this population with a prevalence of 34.2% and predominantly in females and older children, while hallux valgus and a high arched foot were the least common abnormalities at 0.6 and 0.7% prevalence rates, respectively. We found no statistically significant relationship between BMI and hindfoot valgus.

CONCLUSION

Hindfoot valgus is the commonest foot and ankle abnormality among primary school children in our locality.

Reliability of laser-assisted hindfoot alignment evaluation

[Purpose] A goniometer is frequently used for static measurement of hindfoot alignment. However, although goniometer measurements require experience, their reliability and validity remain controversial. We developed a hindfoot alignment measurement method by laser as an alternative measure. The purpose of this study was to examine the reliability of laser-assisted hindfoot alignment evaluation. [Participants and Methods] Two non-expert examiners (without medical knowledge), briefly trained in the use of laser-assisted hindfoot alignment evaluation, evaluated hindfoot alignment in 12 healthy participants. [Results] The ICC of the intra-rater reliability was 0.74 for both examiners and the ICC for inter-rater reliability was 0.43. [Conclusion] The good intra-rater and moderate inter-rater reliability of laser-assisted hindfoot alignment evaluation, when used by non-professionals, suggest the laser-assisted hindfoot alignment evaluation may be appropriate for use in clinical practice settings.

Hindfoot alignment of adult acquired flatfoot deformity: A comparison of clinical assessment and weightbearing cone beam CT examinations

BACKGROUND

Clinical assessment of hindfoot alignment (HA) in adult acquired flatfoot deformity (AAFD) can be challenging and weightbearing (WB) cone beam CT (CBCT) may potentially better demonstrate this three-dimensional (3D) deformity. Therefore, we compared clinical and WB CBCT assessment of HA in patients with AAFD.

METHODS

In this prospective study, we included 12 men and 8 women (mean age: 52.2, range: 20-88) with flexible AAFD. All subjects also underwent WB CBCT and clinical assessment of hindfoot alignment. Three fellowship-trained foot and ankle surgeons performed six hindfoot alignment measurements on the CT images. Intra- and Inter-observer reliabilities were calculated using intra-class correlation (ICC). Measurements were compared by paired T-tests, and p-values of less than 0.05 were considered significant.

RESULTS

The mean of clinically measured hindfoot valgus was 15.2 (95% confidence interval [CI]: 11.5-18.8) degrees. It was significantly different from the mean values of all WB CBCT measurements: Clinical Hindfoot Alignment Angle, 9.9 (CI: 8.9-11.1) degrees; Achilles tendon/Calcaneal Tuberosity Angle, 3.2 (CI: 1.3-5.0) degrees; Tibial axis/Calcaneal Tuberosity Angle, 6.1 (CI: 4.3-7.8) degrees; Tibial axis/Subtalar Joint Angle 7.0 (CI: 5.3-8.8) degrees, and Hindfoot Alignment Angle 22.8 (CI: 20.4-25.3) degrees. We found overall substantial to almost perfect intra- (ICC range: 0.87-0.97) and inter-observer agreements (ICC range: 0.51-0.88) for all WB CBCT measurements.

CONCLUSIONS

Using 3D WB CBCT can help characterize the valgus hindfoot alignment in patients with AAFD. We found the different CT measurements to be reliable and repeatable, and to significantly differ from the clinical evaluation of hindfoot valgus alignment.

LEVEL OF EVIDENCE

Level II-prospective comparative study.

Correlation of Clinical Evaluation and Radiographic Hindfoot Alignment in Stage II Adult-Acquired Flatfoot Deformity

BACKGROUND

Previous work has demonstrated that the amount of radiographic hindfoot correction required at the time of adult-acquired flatfoot deformity (AAFD) operative treatment can be predicted by the amount of radiographic deformity present before surgery. Successful outcomes after reconstruction are closely correlated with hindfoot valgus correction. However, it is not clear if differences exist between clinical and radiographic assessment of hindfoot valgus. The purpose of this study was to evaluate the correlation between radiographic and clinical evaluation of hindfoot alignment in patients with stage II AAFD.

METHODS

Twenty-nine patients (30 feet) with stage II AAFD, 17 men and 12 women, mean age of 51 (range, 20-71) years, were prospectively recruited. In a controlled and standardized fashion, bilateral weightbearing radiographic hindfoot alignment views were taken. Radiographic parameters were measured by 2 blinded and independent readers: hindfoot alignment angle (HAA) and hindfoot moment arm (HMA). Clinical photographs of hindfoot alignment were taken in 3 different vertical camera angulations (0, 20, and 40 degrees). Pictures were assessed by the same readers for standing tibiocalcaneal angle (STCA) and resting calcaneal stance position (RCSP). Intra- and interobserver reliability were assessed by Pearson/Spearman's and intraclass correlation coefficient (ICC), respectively. Relationship between clinical and radiographic hindfoot alignment was evaluated by a linear regression model. Comparison between the different angles (RCSP, STCA, and HAA) was performed using the Wilcoxon rank-sum test. P values of less than .05 were considered significant.

RESULTS

We found overall almost perfect intraobserver (range, 0.91-0.99) and interobserver reliability (range, 0.74-0.98) for all measures. Mean value and confidence interval (CI) for RCSP and STCA were 10.8 degrees (CI, 10.1-11.5) and 12.6 degrees (CI, 11.7-13.4), respectively. The position of the camera did not influence readings of clinical alignment ( P > .05). The mean HMA was 18.7 mm (CI, 16.3-21.1 mm), and the mean HAA was 23.5 degrees (CI, 21.1-26.0). Clinical and radiographic hindfoot alignment were found to significantly correlate ( P < .05). However, the radiographic HAA demonstrated increased valgus compared to both clinical alignment measurements, with a mean difference of 12.8 degrees from the RCSP (CI, 11.0-14.5, P < .0001) and 11.0 degrees from the STCA (CI, 9.2-12.8, P < .0001).

CONCLUSION

We found significant correlation between radiographic and clinical hindfoot alignment in patients with stage II AAFD. However, radiographic measurements of HAA demonstrated significantly more pronounced valgus alignment than the clinical evaluation. The results of our study suggest that clinical evaluation of hindfoot alignment in patients with AAFD potentially underestimates the bony valgus deformity. One should consider these findings when using clinical evaluation in the treatment algorithm of flatfoot patients.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Measurement properties of visual rating of postural orientation errors of the lower extremity - A systematic review and meta-analysis

OBJECTIVES

To systematically review measurement properties of visual assessment and rating of Postural Orientation Errors (POEs) in participants with or without lower extremity musculoskeletal disorders.

METHODS

A systematic review according to the PRISMA guidelines was conducted. The search was performed in Medline (Pubmed), CINAHL and EMBASE (OVID) databases until August 2016. Studies reporting measurement properties for visual rating of postural orientation during the performance of weight-bearing functional tasks were included. No limits were placed on participant age, sex or whether they had a musculoskeletal disorder affecting the lower extremity.

RESULTS

Twenty-eight articles were included, 5 of which included populations with a musculoskeletal disorder. Visual rating of the knee-medial-to-foot position (KMFP) was reliable within and between raters, and meta-analyses showed that this POE was valid against 2D and 3D kinematics in asymptomatic populations. Other segment-specific POEs showed either poor to moderate reliability or there were too few studies to permit synthesis. Intra-rater reliability was at least moderate for POEs within a task whereas inter-rater reliability was at most moderate.

CONCLUSIONS

Visual rating of KMFP appears to be valid and reliable in asymptomatic adult populations. Measurement properties remain to be determined for POEs other than KMPF.

Challenging the foundations of the clinical model of foot function: further evidence that the root model assessments fail to appropriately classify foot function

BACKGROUND

The Root model of normal and abnormal foot function remains the basis for clinical foot orthotic practice globally. Our aim was to investigate the relationship between foot deformities and kinematic compensations that are the foundations of the model.

METHODS

A convenience sample of 140 were screened and 100 symptom free participants aged 18-45 years were invited to participate. The static biomechanical assessment described by the Root model was used to identify five foot deformities. A 6 segment foot model was used to measure foot kinematics during gait. Statistical tests compared foot kinematics between feet with and without foot deformities and correlated the degree of deformity with any compensatory motions.

RESULTS

None of the deformities proposed by the Root model were associated with distinct differences in foot kinematics during gait when compared to those without deformities or each other. Static and dynamic parameters were not correlated.

CONCLUSIONS

Taken as part of a wider body of evidence, the results of this study have profound implications for clinical foot health practice. We believe that the assessment protocol advocated by the Root model is no longer a suitable basis for professional practice. We recommend that clinicians stop using sub-talar neutral position during clinical assessments and stop assessing the non-weight bearing range of ankle dorsiflexion, first ray position and forefoot alignments and movement as a means of defining the associated foot deformities. The results question the relevance of the Root assessments in the prescription of foot orthoses.

Runners with patellofemoral pain have altered biomechanics which targeted interventions can modify: A systematic review and meta-analysis

Patellofemoral pain (PFP) is the most prevalent running pathology and associated with multi-level biomechanical factors. This systematic review aims to guide treatment and prevention of PFP by synthesising prospective, observational and intervention studies that measure clinical and biomechanical outcomes in symptomatic running populations. Medline, Web of Science and CINAHL were searched from inception to April 2015 for prospective, case-control or intervention studies in running-related PFP cohorts. Study methodological quality was scored by two independent raters using the modified Downs and Black or PEDro scales, with meta-analysis performed where appropriate. 28 studies were included. Very limited evidence indicates that increased peak hip adduction is a risk factor for PFP in female runners, supported by moderate evidence of a relationship between PFP and increased peak hip adduction, internal rotation and contralateral pelvic drop, as well as reduced peak hip flexion. Limited evidence was also identified that altered peak force and time to peak at foot level is a risk factor for PFP development. Limited evidence from intervention studies indicates that both running retraining and proximal strengthening exercise lead to favourable outcomes in both pain and function, but only running retraining significantly reduces peak hip adduction, suggesting a possible kinematic mechanism. Put together, these findings highlight limited but coherent evidence of altered biomechanics which interventions can alter with resultant symptom change in females with PFP. There is a clear need for high quality prospective studies of intervention efficacy with measurement of explanatory mechanisms.

A comparative study of the feet of middle-aged women in Korea and the Maasai tribe

Background

Members of the Maasai tribe spend their days either barefoot or wearing traditional shoes made from recycled car tires. Although they walk long distances (up to 60 km) daily, they do not generally experience foot ailments. Here, we compared parameters associated with the feet, ankles, and gait of middle-aged women in Korea and the Maasai tribe.

Methods

Foot length, calf circumference, hindfoot alignment, step length, cadence, and walking velocity were compared among 20 middle-aged Korean and bush-living Maasai women. Static and dynamic Harris mat footprints were taken to determine the distribution of forefoot pressure patterns during walking. We also compared several radiographic parameters with standing foot and ankle radiographs.

Results

The mean foot length and width were significantly longer in Maasai women. Interestingly, 38 ft (96 %) in the Maasai group showed a claw deformity of the toe (s). There were no statistically significant differences in gait-related indices and Harris mat findings between the two groups. On radiographic analysis, tibial anterior surface angle, tibial lateral surface angle, talonavicular coverage angle, talo-first metatarsal angle, Meary angle, and naviculo-cuboidal overlap were significantly greater in the Maasai group, whereas hallux valgus angle and the first and second intermetatarsal angle were greater in the Korean group.

Conclusions

Middle-aged women from the Maasai tribe showed a higher prevalence of abducted forefeet, everted hindfeet, and fallen medial longitudinal arches than did Korean women, while Korean women showed a higher prevalence of hallux valgus, a preserved medial longitudinal arch, and toes that are free from claw deformity.

Salient features of the Maasai foot: analysis of 1,096 Maasai subjects

Background

The Maasai are the most widely known African ethnic group located in Kenya and northern Tanzania. Most spend their days either barefoot or in their traditional shoes made of car tires. Although they walk long distances of up to sixty kilometers a day, they do not suffer from any foot ailments. Little is known about their foot structure and gait. The goal of this investigation was to characterize various aspects of Maasai foot in standing and walking.

Methods

Foot length, calf circumference, hindfoot alignment, step length, cadence, and walking velocity were obtained from 1,096 adult Maasai people (545 males and 551 females; mean age, 40.28 ± 14.69 years; age range, 16 to 65 years). All included subjects were from rural areas, where the primary terrain was sandy soil, who spend most of their lifetime barefoot, walking. They all denied any medical history or previous symptoms related to foot problems. A trained clinician scanned all feet for deformities. Static (standing) and dynamic (walking) Harris mat footprints were taken to determine the distribution of forefoot pressure patterns during walking.

Results

The average foot length was 250.14 ± 18.12 mm (range, 210 to 295 mm) and calf circumference was 32.50 ± 3.22 cm (range, 25 to 41 cm). The mean hindfoot alignment was 6.21° ± 1.55° of valgus. Sixty-four subjects (5.84%) had bilateral flat-shaped feet with a low medial longitudinal arch that exactly matched the broad pattern of their static footprints. Step length, cadence, and walking velocity were 426.45 ± 88.73 cm (range, 200 to 690 cm), 94.35 steps/min (range, 72 to 111 steps/min), and 40.16 ± 8.36 m/min (range, 18.20 to 63.36 m/min), respectively. A total of 83.39% subjects showed unilateral or bilateral deformities of multiple toes regardless of age. The most frequent deformity was clawing (98.79%) of which the highest incidence occurred with the fifth toe (93.23%). Dynamic footprints showed even pressure patterns throughout the forefoot (64.87%), followed by lateral forefoot pressure concentration patterns (21.81%).

Conclusions

Our study shows the distinct parameters that provide more insight into the Maasai foot.

Musculoskeletal conditions of the foot and ankle: assessments and treatment options

Musculoskeletal conditions of the foot and ankle are an important public health challenge due to their increasing incidence combined with their substantial negative impact on patients' quality of life. Non-pharmacological treatments serve as the first line of treatment and are frequently used for patients with musculoskeletal conditions of the foot and ankle. This review provides a summary of the assessments and non-invasive treatment options based upon available evidence. Recent studies show that individuals with foot and ankle pain have multiple co-existing impairments in alignment, motion, load distribution and muscle performance that may be evident in static and/or dynamic tasks. In addition, both clinical and epidemiological studies support the inter-dependence between the foot and proximal joints. For instance, aberrant foot structure has been linked to foot osteoarthritis (OA), as well as OA and pain at the knee and hip. Most recently, advances in motion capture technology and plantar load distribution measurement offer opportunities for precise dynamic assessments of the foot and ankle. In individuals with musculoskeletal conditions of the foot and ankle, the chief objectives of treatment are to afford pain relief, restore mechanics (alignment, motion and/or load distribution) and return the patient to their desired level of activity participation. Given that most patients present with multiple impairments, combinational therapies that target foot-specific as well as global impairments have shown promising results. In particular, in individuals with rheumatoid arthritis and other rheumatic diseases, comprehensive rehabilitation strategies including early detection, foot-based interventions (such as orthoses) and wellness-based approaches for physical activity and self-management have been successful. While significant improvements have been made in the last decade to the assessment and treatment of foot and ankle conditions, few randomised clinical trials specifically have investigated patients with foot or ankle conditions to provide global insights into this area. Consequently, current recommendations vary based upon the scope of studies presented in this review as well as the strength of studies. This review indicates a need for more in-depth investigations into the components of assessment and treatment options for foot and ankle musculoskeletal conditions.

Inter-assessor reliability of practice based biomechanical assessment of the foot and ankle

Background

There is no consensus on which protocols should be used to assess foot and lower limb biomechanics in clinical practice. The reliability of many assessments has been questioned by previous research. The aim of this investigation was to (i) identify (through consensus) what biomechanical examinations are used in clinical practice and (ii) evaluate the inter-assessor reliability of some of these examinations.

Methods

Part1: Using a modified Delphi technique 12 podiatrists derived consensus on the biomechanical examinations used in clinical practice. Part 2: Eleven podiatrists assessed 6 participants using a subset of the assessment protocol derived in Part 1. Examinations were compared between assessors.

Results

Clinicians choose to estimate rather than quantitatively measure foot position and motion. Poor inter-assessor reliability was recorded for all examinations. Intra-class correlation coefficient values (ICC) for relaxed calcaneal stance position were less than 0.23 and were less than 0.14 for neutral calcaneal stance position. For the examination of ankle joint dorsiflexion, ICC values suggest moderate reliability (less than 0.61). The results of a random effects ANOVA highlight that participant (up to 5.7°), assessor (up to 5.8°) and random (up to 5.7°) error all contribute to the total error (up to 9.5° for relaxed calcaneal stance position, up to 10.7° for the examination of ankle joint dorsiflexion). Kappa Fleiss values for categorisation of first ray position and mobility were less than 0.05 and for limb length assessment less than 0.02, indicating slight agreement.

Conclusion

Static biomechanical assessment of the foot, leg and lower limb is an important protocol in clinical practice, but the key examinations used to make inferences about dynamic foot function and to determine orthotic prescription are unreliable.

The accuracy of an automasking algorithm in plantar pressure measurements

Masking algorithms provide a way to analyze plantar pressure parameters based on distinct anatomical regions of the foot. No study has addressed their accuracy. The purpose of this study was to determine the accuracy of the Novel® ten-region standard masking algorithm in both dynamic and static measurements in normal feet. Static and dynamic plantar pressure measurements were collected from ten normal subjects (20 ft) with and without 10-mm radiopaque markers placed under the first through fifth metatarsal heads, fifth metatarsal base, and first proximal phalanx. The automask was then applied to subdivide the foot into distinct anatomical areas. Weight-bearing AP radiographs were obtained with and without markers. Plantar pressures and radiographs were overlaid. The percent accuracy of each marker within its appropriate mask region was calculated. The average accuracies of the automasking algorithm regions for dynamic and static measurements, respectively, were 98.8% and 90.4% (1MH), 89.9% and 80.6% (2MH), 98.6% and 81.4% (3MH), 96.8% and 82.3% (4MH), 93.1% and 80.8% (5MH), 97.3% and 92.5% (5MB), and 91.2% and 64.2% (1PPH). Marker presence did not alter foot structure or function as determined by intermetatarsal angles (range, p = 0.361 to p = 0.649) and the center of pressure excursion index (p = 0.727), respectively. The automasking algorithm accurately identifies most foot regions in normal feet, particularly in gait. Such accuracy may be reduced in the setting of foot deformity. Understanding the accuracy of masking algorithms may help guide the interpretation of plantar pressure measurements and ultimately both conservative and operative treatment decisions.

Foot Build Registration System (FBRS) to evaluate foot posture: a reliability study with healthy subjects and patients with Charcot-Marie-Tooth disease

BACKGROUND

To follow the weight bearing foot posture in subjects, a measurement tool using digital photography was developed, Foot Build Registration System (FBRS) (Fig. 1) [M. Van der Cruijsen, Voetvorm registratie systeem, Boxmeer (1999).]. This study's objective was to investigate the reproducibility of FBRS measurements in healthy feet and feet of patients with Charcot-Marie-Tooth disease (CMT).

METHODS

Reproducibility and reliability studies were performed in several foot views in healthy and CMT patients.

RESULTS

These studies showed that the variability of the 95% prediction limit depended upon the foot view being studied and whether markers had been drawn. Some individuals had a higher intra-individual variability than others. Limiting data collection to those individuals with a SD<3.5 degrees for a series of five or more photographs per view improved the 95% prediction limits. These varied between 2.8 degrees and 7.7 degrees.

CONCLUSIONS

If the differences found between registration are greater than the abovementioned, values can be attributed to time or operative management for healthy and CMT patients and not to measurement error.

Clinical or radiologic measurements and 3-D gait analysis in children with pes planus

BACKGROUND

Static measurement in clinical and radiologic evaluation is often used in assessment of pes planus, but it is important to know whether pes planus leads to abnormal gait pattern. The purpose of the present study was to assess the clinical and radiologic findings of children with pes planus and the relationship between clinical, radiologic findings and parameters obtained in 3-D gait analysis.

METHODS

Thirteen children with pes planus were selected. Physical measurements included femoral anteversion, internal and external rotation, thigh-foot angle (TFA), and resting calcaneal stance position (RCSP). Radiologic measurements included talo-calcaneal angle (TCA), talometatarsal angle (TMA), calcaneal pitch, and forefoot adduction on simple X-ray, and femoral anteversion, tibial torsion and rotation on computed tomography (CT). 3-D gait analysis was also performed and kinetic and kinematic data were obtained in sagittal, frontal, and transverse plane. The correlation between clinical, radiologic, and gait analysis data was investigated.

RESULTS

RCSP was found to be significantly correlated with TMA. TMA was also correlated with TCA. TCA on simple X-ray was correlated with maximal internal and external rotation angle of the knee joint on gait analysis.

CONCLUSION

TMA was the factor most related to degree of calcaneal valgus measured on physical exam. Larger TCA contributed to decreased maximal external rotation and increased maximal internal rotation in gait cycle. Clinical or radiological methods, however, had very limited ability to predict gait deviance of pes planus.

The development of an intraoperative plantar pressure assessment device

BACKGROUND

The goal of this study was to develop an accurate and reliable supine plantar pressure measurement apparatus that could potentially be used in the operating room to guide operative decision making. It was hypothesized that plantar pressures would be similar in supine and vertical posture trials.

MATERIALS AND METHODS

A supine plantar pressure system was developed using the Pliance 32 sensor array (Novel, Munich, Germany). Accuracy was tested with a standardized manometer and the Trublu calibration system (Novel). Next, bilateral feet of 10 healthy, asymptomatic patients were tested in the apparatus by two separate investigators. Intraclass correlation coefficients (ICC) were calculated to determine intrarater and interrater reliability for parameters of average mean pressure (AMP), peak pressure (PP) and percentage of total force (PF). Finally, plantar pressures were tested in vertical posture and compared to supine parameters.

RESULTS

The sensor was both linear and accurate. The ICC values demonstrated that the sensor was reliable for AMP (0.66 to 0.93), PP (0.75 to 0.94), and PF (0.69 to 0.97). In general, AMP, PP, and PF values were significantly different at most anatomical regions for supine and vertical posture trials (p < 0.0001).

CONCLUSION

This intraoperative pressure measurement system provided an accurate, linear, and reliable method to measure plantar pressure parameters in the supine subject. These measures were similar in magnitude to vertical posture, but were statistically different.

CLINICAL RELEVANCE

This intraoperative plantar pressure system could guide operative reconstruction of foot deformities whose outcome depends on the distribution of pressures across the plantar foot.

Reevaluating the way we classify the diabetic foot: restructuring the diabetic foot risk classification system of the International Working Group on the Diabetic Foot

OBJECTIVE

To separately evaluate peripheral arterial occlusive disease (PAOD) and foot ulcer and amputation history in a diabetic foot risk classification to predict foot complications.

RESEARCH DESIGN AND METHODS

We evaluated 1,666 diabetic patients for 27.2 +/- 4.2 months. Patients underwent a detailed foot assessment and were followed at regular intervals. We used a modified version of the International Working Group on the Diabetic Foot's (IWGDF's) risk classification to assess complications during the follow-up period.

RESULTS

There were more ulcerations, infections, amputations, and hospitalizations as risk group increased (chi(2) for trend P < 0.001). When risk category 2 (neuropathy and deformity and/or PAOD) was stratified by PAOD, there were more complications in PAOD patients (P < 0.01). When risk group 3 patients (ulceration or amputation history) were separately stratified, there were more complications in subjects with previous amputation (P < 0.01).

CONCLUSIONS

We propose a new risk classification that predicts future foot complications better than that currently used by the IWGDF.

Reliability and normative values of the foot line test: a technique to assess foot posture

STUDY DESIGN

Test-retest reliability.

OBJECTIVE

To examine the reliability and report normative values of a novel test, the foot line test (FLT), to describe foot morphology.

BACKGROUND

Numerous foot examinations are performed each day, but most existing examination techniques have considerable limitations regarding reliability and validity.

METHODS

One hundred thirty subjects with mean foot size 44 (41-50 European size) participated. Two examiners, blinded to each other's measurements, measured the right foot of the subjects twice and the left foot once. The position of the most medial aspect of the navicular in the mediolateral direction was projected vertically onto a piece of paper placed under the subject's foot, and compared to the position of the forefoot and hindfoot to obtain the FLT value.

RESULTS

FLT values ranged from -8 to 14 mm, with a mean (+/-SD) of 3.7 +/- 3.4 mm. The intratester reproducibility reported by SEM was 0.8 mm for tester 1 and 0.9 mm for tester 2, while intertester SEM was 1.4 mm for the right foot and 1.3 mm for the left foot. The intrarater ICC was 0.95 for tester 1 and 0.94 for tester 2, while the interrater ICC was 0.86 (left foot) and 0.83 (right foot). There was no significant association between foot size and FLT values.

CONCLUSION

The FLT is a reproducible technique to assess foot posture.