Immediate effects of foot orthoses on lower limb biomechanics, pain, and confidence in individuals with patellofemoral osteoarthritis

Journal Pre-proof Immediate effects of foot orthoses on lower limb biomechanics, pain, and confidence in individuals with patellofemoral osteoarthritis Jade M. Tan, Kane J. Middleton, Harvi F. Hart, Hylton B. Menz, Kay M. Crossley, Shannon E. Munteanu, Natalie J. Collins

PII:

S0966-6362(19)30373-X

DOI:

https://doi.org/10.1016/j.gaitpost.2019.10.019

Reference:

GAIPOS 7358

To appear in:

Gait & Posture

Received Date:

2 April 2019

Revised Date:

2 October 2019

Accepted Date:

12 October 2019

Please cite this article as: Tan JM, Middleton KJ, Hart HF, Menz HB, Crossley KM, Munteanu SE, Collins NJ, Immediate effects of foot orthoses on lower limb biomechanics, pain, and confidence in individuals with patellofemoral osteoarthritis, Gait and amp; Posture (2019), doi: https://doi.org/10.1016/j.gaitpost.2019.10.019

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier.

Immediate effects of foot orthoses on lower limb biomechanics, pain, and confidence in individuals with patellofemoral osteoarthritis

Authors: Jade M. Tan1,2, Kane J. Middleton2,3, Harvi F. Hart2,4, Hylton B. Menz1,2, Kay M. Crossley,2, Shannon E. Munteanu1,2, and Natalie J. Collins2,5. Discipline of Podiatry, School of Allied Health, Human Services and Sport, College of Science, Health and Engineering, La Trobe

ro of

1.

University, Melbourne, Australia, 3086. 2.

La Trobe Sport and Exercise Medicine Research Centre, La Trobe University, Melbourne, Australia, 3086.

3.

Discipline of Sport and Exercise Science, School of Allied Health, Human Services and Sport, College of Science, Health and

4.

-p

Engineering, La Trobe University, Melbourne, Australia, 3086.

Department of Physical Therapy, Faculty of Health Sciences, Collaborative Training Program in Musculoskeletal Health

Research, and Bone and Joint Institute, The University of Western Ontario, London, Canada, N6A 3K7 School of Health and Rehabilitation Sciences, Faculty of Health and Behavioural Sciences, The University of Queensland,

re

5.

lP

Brisbane, Australia, 4072.

Corresponding author: Jade M. Tan

Foot orthoses cause instant changes to ankle biomechanics in people with PFOA. No biomechanical difference between flat inserts (sham) and shoes, indicating a good sham device. Foot orthoses do not alter knee pain or confidence immediately in people with PFOA.

Jo

 

ur

Highlights



na

[email protected]

Abstract Background Foot orthoses are a recommended treatment for patellofemoral (PF) pain and a number of lower limb osteoarthritis (OA) conditions. However, their mechanism of effect is poorly understood. Research question To compare the immediate effects of foot orthoses and flat inserts on lower limb biomechanics, knee

ro of

pain and confidence in individuals with PFOA. Methods

Twenty-one participants (14 females; mean ± SD age 58 ± 8 years) with PFOA underwent three-

dimensional motion analysis during level-walking, stair ascent and stair descent under three footwear

-p

conditions: (i) their own shoes; (ii) prefabricated foot orthoses; and (iii) flat shoe inserts. Participants reported their average levels of knee pain and confidence after each task. Data were analysed with

re

repeated-measures analysis of variance (ANOVA), effect sizes (partial eta squared), and Bonferroni

lP

post-hoc tests. Results

na

During level-walking, there was a significant main effect of foot orthoses on peak ankle dorsiflexion angle (F2=0.773, p<0.001, ƞ2=0.773) and peak ankle external dorsiflexion moment (F2=0.356, p=0.046, ƞ2=0.356). Foot orthoses decreased the peak ankle dorsiflexion angle compared to the flat

ur

insert and shoe conditions, and decreased the peak ankle external dorsiflexion moment relative to flat

Jo

inserts. During stair descent, there was a significant main effect of foot orthoses on peak ankle external dorsiflexion moment (F2=0.823, p=0.006, ƞ2=0.738), with a trend towards lower peak dorsiflexion moment for foot orthoses compared to the flat insert and shoe conditions. No significant main effects were observed during stair ascent. No other lower limb biomechanical changes were observed across all three conditions. Knee pain and confidence scores were not significantly different across the three conditions.

Significance Prefabricated foot orthoses altered sagittal plane biomechanics of the ankle during level-walking and stair descent in individuals with PFOA. Further research is required to determine whether these changes are clinically beneficial.

Keywords Gait analysis

ro of

Walking Stairs Kinematics

Jo

ur

na

lP

re

-p

Kinetics

1.

Introduction

Patellofemoral (PF) osteoarthritis (OA) affects 43% of individuals with knee pain [1]. PF involvement often develops before tibiofemoral (TF) OA, and increases the likelihood of TFOA incidence and disease progression [2]. Furthermore, PFOA is a more prominent source of symptoms compared to TFOA [3], occurs in middle-aged individuals [2], and affects more females than males [4]. Foot orthoses are an effective treatment for patellofemoral pain (PFP) [5]. Biomechanical studies on the effects of foot orthoses in individuals with PFP have demonstrated transverse plane knee rotation

ro of

[6], hip adduction [6], ankle joint inversion moments [7], and increased vastus medialis and gluteus medius activity [8]. These changes could potentially influence PF loading and provide an explanation for the apparent effectiveness of foot orthoses in the management of PF symptoms.

-p

A theoretical link between PFP and PFOA has been proposed, with similar features and

biomechanical impairments observed in both populations [9]. However, due to age-related differences

re

in foot mobility in individuals with PFP [10], it cannot be assumed that foot orthoses will have a similar biomechanical effect in individuals with PFOA. Therefore, the primary aim of this study was

lP

to determine the immediate effects of foot orthoses and flat shoe inserts on lower limb biomechanics in individuals with PFOA. The secondary aim of this study was to evaluate the immediate effects of

na

these interventions on knee pain and confidence. We hypothesised that foot orthoses would increase the dorsiflexion angle and moment at the ankle, and improve knee pain and confidence compared to

Jo

ur

the flat insert.

2.

Methods

This study used a within-subject, randomised, cross-over design to evaluate the immediate effects of foot orthoses and flat shoe inserts on lower limb biomechanics, pain, and confidence. Data for this study was collected at the baseline testing session of a pilot randomised controlled trial (RCT) evaluating the six-week effects of foot orthoses compared to flat shoe inserts [11]. Ethical approval

for this study was granted by La Trobe University Human Ethics Committee (S15/286) and the trial was registered on the Australian New Zealand Clinical Trials Registry (ACTRN12616001287426). Volunteers were recruited from the greater Melbourne community via paid advertisements (e.g. local newspapers, seniors’ magazines), free advertisements (e.g. community newsletters, flyers on noticeboards and in clinical waiting rooms), recruitment stands at local markets and fun runs, and referrals from physiotherapists and podiatrists. In order to increase the generalisability of our findings, this study used a clinical diagnosis of PFOA based on the National Institute for Health and Care

ro of

Excellence (NICE) guidelines [12]. Volunteers were eligible for participation in this study based on the following criteria derived for the pilot RCT: (i) aged 50 to 75 years; (ii) anterior or retropatellar knee pain aggravated by ≥2 PF joint loading activities (e.g. stair ambulation, squatting, rising from

sitting); (iii) pain during these activities on most days in the past month; (iv) pain severity ≥30mm on

-p

a 100mm Visual Analogue Scale (VAS) during aggravating activities; (v) either no morning jointrelated stiffness or morning stiffness that lasts no longer than 30 minutes; and (vi) ability to

re

understand spoken and written English. Volunteers were excluded if they had: (i) concomitant pain

lP

from other knee structures, hip, or lumbar spine; (ii) recent treatment for knee pain; (iii) any foot condition precluding the use of shoe inserts; (iv) knee or hip arthroplasty/osteotomy; (v) neurological or systemic arthritic conditions; (vi) physical inability to undertake testing procedures; and (vii)

na

inability to understand spoken and written English. The knee rated most severe by participants with bilateral PFOA was selected as the study knee. For those with equal symptoms, the right knee was

Jo

ur

chosen.

2.1. Protocol

A two-stage screening process determined suitability for inclusion. Firstly, a preliminary email or telephone interview was conducted. Potential participants then attended the gait laboratory for a comprehensive musculoskeletal examination by an experienced musculoskeletal podiatrist, to ensure participants were primarily experiencing PFOA symptoms. The musculoskeletal examination included: (i) palpation of the PF joint and surrounding soft tissue and osseous structures; (ii)

identification of knee effusion; (iii) hip quadrant and lumbar spine range of motion tests to ensure knee pain did not arise from concomitant structures; and where required (iv) examination of the foot for any conditions precluding the use of shoe inserts (e.g. ganglions). Participants provided written informed consent before the musculoskeletal examination was undertaken. At the completion of the musculoskeletal examination, eligible participants completed clinical measures, patient-reported outcome measures (PROMs), and biomechanical testing during the same appointment, where

ro of

possible.

2.2. Interventions

Interventions used for this study were prefabricated arch contouring foot orthoses, and flat shoe

-p

inserts, which were fitted by a podiatrist during the testing session. The order of testing the conditions was randomised using an online randomisation program (http://www.randomization.com), and the

2.2.1. Prefabricated foot orthoses

lP

re

intervention allocation was concealed from the participant.

Commercially available prefabricated full length arch contouring foot orthoses (Vasyli® Medical,

na

Labrador, Australia) constructed from high-density (Shore A 75ᵒ) ethylene-vinyl acetate (EVA), with inbuilt arch support, and a 6ᵒ varus wedge (Fig. 1) were used as the test insert for this study. The foot

ur

orthoses were covered with a synthetic fabric (Cambrelle®, Camtex Fabrics, Cumbria, CA, USA) top

Jo

cover to ensure no differentiation could be made to the flat insert.

2.2.2. Flat shoe inserts A flat shoe insert constructed from high-density (Shore A 75ᵒ) EVA of uniform thickness along its full length (3mm), with no inbuilt arch or varus wedging, served as the control insert (Fig. 1). The flat shoe inserts were covered with the same synthetic fabric top cover as the foot orthoses.

2.3. Participant characteristics Demographic characteristics, medical history and medications were documented using a structured questionnaire. Height and mass were measured using a stadiometer and digital scales, respectively, and body mass indices (BMI) calculated as weight (kg)/height (m)2. Footwear was assessed using five out of the six items from the Footwear Assessment Tool (item six excluded as it was not of interest in this study) [13]. Clinical tests of foot and ankle mobility were conducted using established and

ro of

reliable methods, including: (i) 6-item Foot Posture Index (FPI) [14]; (ii) weight bearing ankle joint dorsiflexion (knee to wall test) [15]; and (iii) midfoot and arch height mobility/arch indices [16]. PROMs used to characterise the cohort included: (i) the Knee Injury and Osteoarthritis Outcome

Score (KOOS) [17]; (ii) the Anterior Knee Pain Scale (AKPS) [18]; and (iii) severity of average and

-p

maximum pain over the preceding week on a 100mm VAS (terminal descriptors 0mm = no pain,

lP

2.4. Biomechanical data collection

re

100mm = worst pain possible) [19].

Lower limb biomechanical data were collected while the participant performed level-walking, stair

na

ascent, and stair descent tasks under three test conditions: (i) foot orthoses, (ii) flat inserts, and (iii) their shoes alone (control). Both shoe inserts were tested in the participant’s own shoe. A neutral shoe

ur

(Mizuno Wave Rider, Mizuno Corporation, Chiyoda, Tokyo, Japan) was used if a participant did not have appropriate footwear. Kinematic data were recorded using ten-camera opto-reflective motion

Jo

capture system (Vicon Motion Systems Ltd, Oxford, UK; 100 Hz), while two embedded force plates (Kistler, type 9865B, Winterthur, Switzerland and AMTI, OR6, MA, USA; 1000 Hz) simultaneously captured ground reaction force data during walking. A third force plate (AMTI Accugait, AMTI, Watertown, MA, USA) was used to collect stair ascent and descent data. Vicon Nexus software was used to capture synchronised kinematic and force plate data. Three-dimensional joint kinematics of the ankle, knee, and hip were determined using Plug-in-Gait [20]. Each participant underwent

calibration whereby their height, weight, ankle width, knee width, anterior superior iliac spine to greater femoral trochanter distance, and distance between left and right anterior superior iliac spines were recorded. Nineteen 14mm diameter retro-reflective markers were positioned bilaterally at the base of the second metatarsal, bilaterally at the posterior heel, bilaterally on the medial and lateral malleoli, bilaterally on the lateral aspect of the tibia, bilaterally on the lateral aspect of the femur, bilaterally on anterior and posterior superior iliac spines, 10th thoracic vertebrae, 2nd thoracic vertebrae, and the sternum (Supplementary files Fig. 1a and 1b). To calculate knee joint centres, participants completed a static trial with bilateral knee alignment devices (KAD, Motion Lab Systems

ro of

Inc., LA, USA) (Supplementary file Fig. 1a). A single KAD was placed on each knee, with the medial pad positioned directly on the medial femoral epicondyle, and the lateral pad positioned directly over the TF joint line. After the static trial was completed, each KAD was replaced with a single marker

-p

over the exact location of the lateral pad of the KAD (Supplementary file Fig. 1b), and the medial malleoli markers were removed.

re

Participants then performed level-walking at a self-selected speed along a 12-metre walkway, as well

lP

as stair ascent and descent tasks, under the three test conditions. Testing was repeated until six successful trials were recorded for each of the three test conditions. For a trial to be considered successful, total foot contact needed to occur on one of the two embedded force plates without

na

disrupting gait, and all three force plates for stair ambulation. Marker trajectories were filtered using a Woltring Filter routine with a 10mm predicted mean squared

ur

error. Hip, knee, and ankle joint kinematics and moments were calculated during the stance phase of

Jo

gait (heel contact to toe off), with stance phase reported as 0 to 100%. Data were averaged across a minimum of three trials for level-walking and two trials for stair ambulation, and moment data were normalised to body mass. All data were extracted using a custom Matlab program (Mathworks Inc; Natick, MA, USA), with all time-series data temporally normalised to 101 data points using cubic spline interpolation. Variables of interest were peak flexion and extension angles and moments of the hip, knee, and ankle during early stance, peak flexion and extension angles of the hip and ankle during stance phase, peak

plantarflexion and dorsiflexion moments of the ankle during stance phase, and peak knee adduction moments during early and late stance. These variables were selected based on known biomechanical differences previously reported in PFP [21] and PFOA [22] cohorts, compared to controls. Kinetic data were reported as external joint moments.

2.5. Measures of pain and confidence The primary investigator (JMT) administered PROMs during biomechanical testing. The PROMs

ro of

included: (i) knee pain severity using a 100mm VAS (terminal descriptors 0mm = no pain, 100mm = worst pain possible) and (ii) knee confidence using a 100mm VAS, with the question phrased as “how confident did you feel completing that task?” (terminal descriptors 0mm = very confident, 100mm =

re

-p

not confident at all).

2.6. Sample size

lP

As this was a nested study, the sample size was determined for the pilot RCT using an a priori power analysis based on the primary outcome measures VAS, KOOS, and AKPS. The minimal clinical important difference (MCID) for pain VAS is 15mm [19]. Using a standard deviation of 20mm, a

na

power level of 0.8, an alpha level of 0.05, and accounting for a dropout rate of 10%, a sample size of 32 participants (i.e. 16 per group) was required for the RCT. A subset of 20 participants was deemed

Jo

study.

ur

sufficient to detect meaningful within-subject differences in the biomechanical immediate effects

2.7. Data processing and statistical analysis Statistical analysis was undertaken using IBM SPSS® Statistics version 24.0 (IBM Corp, NY, USA). Data were time-normalized from 0% to 100% of the stance phase. Stance phase was defined as a vertical ground reaction force (vGRF) ≥20 Newtons (N), with the first frame considered heel strike

and the final frame considered toe-off. For level-walking, stages of stance were defined as; early ≥0% to <50% and late ≥50% to 100% of stance phase. For stair ascent and descent, data were extracted as time point zero being heel strike of the symptomatic limb to toe-off of the ipsilateral limb. All biomechanical data were reported as peak angles and moments for sagittal plane motion of the hip, knee, and ankle, and frontal plane motion of the knee during stance phase. Biomechanical data were visually inspected for trends regarding differences in biomechanics between the three test conditions. Data were then inspected for normality and parametric tests were used to

ro of

report means and standard deviations (SDs). Where data were not normally distributed, nonparametric tests were utilised and data reported as medians and interquartile ranges (IQRs).

Biomechanical variables and PROMs were compared across the three test conditions using repeatedmeasures analysis of variance (ANOVA) with Bonferroni post-hoc tests. Effect sizes were determined

Results

lP

3.

re

to 1.2), large (1.2 to 2.0), and very large (>2.0) [23].

-p

using the partial eta squared (ƞ2) statistic, with results interpreted as small (0.2 to 0.6), moderate (0.6

From February to July 2016, 129 volunteers underwent screening (email/telephone initially, with

na

physical screen as indicated) for the pilot RCT in which 30 were eligible. Four participants declined to participate due to time demands of being in involved in a study and five participants did not consent

ur

to baseline biomechanical testing. Twenty-one participants (14 females; mean  SD age 58  8 years [range 50-75]; BMI 27.0  4.8 kg/m2) with PFOA were enrolled in the biomechanics study (see Table

Jo

1). Common reasons for study exclusion were: currently wearing insoles (n = 21); not enough pain/pain in the wrong region (n = 17); currently receiving physiotherapy treatment (n = 14); a surgical history precluding study involvement (n = 6); unable to commit to the time obligations of being involved in the study (n = 4); too young (n = 3); and reported being diagnosed with rheumatoid arthritis (n = 3).

The effects of foot orthoses and flat inserts on lower limb biomechanics during level-walking are presented in Table 2 and Fig. 2. There was a significant main effect of foot orthoses on peak ankle dorsiflexion angle (F2=0.773, p<0.001, ƞ2=0.773), with post-hoc tests revealing that foot orthoses reduced peak ankle dorsiflexion angle compared to flat inserts (mean difference [MD]=0.3 [95%CI 1.1 to 2.5]) and shoe alone (MD=0.4 [95%CI 0.6 to 2.6]). In addition, there was a significant main effect of foot orthoses on peak ankle dorsiflexion moment (F2=0.356, p<0.046, ƞ2=0.356), with posthoc tests revealing that foot orthoses reduced peak ankle dorsiflexion moment compared to flat inserts

ro of

(MD=0.22Nm/kg [95%CI 0.04 to 1.24]). Effects of foot orthoses and flat inserts on lower limb biomechanics during stair ascent and descent

are presented in Table 3. No significant main effects were observed during stair ascent. During stair descent, there was a significant main effect of foot orthoses on peak external dorsiflexion moment

-p

(F2=0.823, p=0.006, ƞ2=0.738), with a trend towards lower peak dorsiflexion moment for foot

(MD=0.89Nm/kg [95%CI -1.76 to 3.83]).

re

orthoses compared to flat inserts (MD=0.68Nm/kg [95%CI -0.39 to 3.87]) and shoes alone

lP

There were no significant effects of foot orthoses and flat inserts on pain and confidence scores (Table

4.

na

4).

Discussion

ur

The primary objective of this study was to determine the immediate effects of foot orthoses and flat

Jo

inserts on lower limb biomechanics in individuals with PFOA. The secondary objective was to evaluate the immediate effects of foot orthoses on knee pain and confidence during level-walking and stair ambulation. Overall, results do not support the hypotheses of an increase in the dorsiflexion angle and moment at the ankle, or improvements in knee pain and confidence. However, foot orthoses significantly reduce sagittal plane ankle joint kinematics and joint moments during level-walking and stair descent compared to a flat insert. Furthermore, there were no statistically significant differences in knee pain and confidence scores across all three conditions.

Foot orthoses induced distal biomechanical effects in individuals with PFOA without influencing biomechanics at more proximal segments. The reduced peak ankle dorsiflexion angle during levelwalking may be due to the arch support and 6ᵒ varus wedge incorporated into the foot orthosis, which encourages more ankle plantarflexion throughout stance phase (Figure 2). Considering dorsiflexion is a component of foot pronation, and that the biomechanical model used was unable to measure other components of pronation (e.g. calcaneal eversion), it is possible that the foot orthoses did influence foot pronation during gait. However, given that our participants did not exhibit a highly pronated foot posture or increased foot mobility (as indicated by the FPI and Foot Assessment Platform results),

ro of

which has been observed in individuals with PFOA [24], we are unable to draw further conclusions as to the link between foot kinematics, foot orthoses, and PFOA. Further studies are necessary to investigate foot kinematics in more detail using complex biomechanical foot models in this

-p

population.

The reduced peak ankle dorsiflexion moment was coupled with a decrease in peak ankle dorsiflexion

re

angle during level-walking but not stair descent whilst wearing the foot orthoses. The decrease in

lP

peak ankle dorsiflexion moment may be partly due to the known shock absorptive capacity [25] and reduction in peak plantar pressure [26] of the foot orthoses. As participants in this study demonstrated lower foot mobility when compared to young adults [16], the shock absorptive characteristics of foot

na

orthoses may be therapeutically beneficial, particularly given that stair ambulation is an activity which often evokes pain in those with PFOA [2].

ur

We found no biomechanical differences between flat inserts and shoes alone during all three

Jo

functional tasks. This suggests that the flat inserts used in this study could be considered an adequate sham device in future clinical trials investigating the effectiveness of foot orthoses [12]. This result may also help explain the non-significant immediate changes in pain levels observed. The findings of our study differ to previous research demonstrating immediate biomechanical effects in individuals with PFP [27], suggesting that responses to foot orthoses are different in PFOA. The reasons for this are unclear, however the disparity may be due to differences in biomechanical assessment methods and/or foot mobility. As foot mobility has been shown to influence foot orthosis

efficacy in PFP populations [28], a potential explanation for the observed difference in this study is that those with PFOA are typically older and may display less foot mobility, similar to older individuals with PFP [10]. Therefore, reduced foot mobility may limit the capacity of an in-shoe intervention to alter lower limb biomechanics proximal to the foot. There were no significant differences in knee pain during level-walking, stair ascent or descent across the three footwear conditions. This finding contrasts to that of Collins et al. [29], who reported that foot orthoses reduced pain during level-walking and flat insoles reduced pain during stair ambulation.

ro of

This may be explained by the control condition used in each study. In Collins et al. [29], the control condition was a contoured sandal, while in our study, participants wore their own shoes, which are likely to provide more support and comfort than a control sandal.

-p

The finding of no change in confidence scores between all three conditions is clinically useful. This demonstrates that participants can complete pain provoking tasks, whilst using an in-shoe

re

intervention, without resulting in reduced confidence. This observation has important implications for planning treatment in individuals with PFOA, as lack of confidence is a barrier that can often lead to

lP

poor adherence to rehabilitation exercises and treatment [30], which may limit positive outcomes. Strengths of this study include a detailed characterisation of a PFOA cohort and the first known

na

published study investigating the effects of foot orthoses on lower limb biomechanics in individuals with PFOA. However, our findings need to be viewed in light of three key limitations. Firstly, we

ur

used a relatively simple biomechanical model that did not include a multi-segment foot model, which means that changes within the foot were not evaluated in detail and subtle lower limb changes may

Jo

not have been detected. Furthermore, we did not collect any PF joint loading data and therefore, the ability to determine if any lower limb biomechanics translate to changes about the PF joint are limited [22]. Secondly, all participants were tested with the same density (Shore A 75ᵒ), unmodified prefabricated arch contouring foot orthoses. Foot orthoses are frequently customised by adding wedges or via heat molding to enhance comfort [12] and/or biomechanical alignment, which could influence both biomechanical changes and measures of pain and function. Finally, despite a moderate sample size of 21 participants for a biomechanical study, due to this being a nested study with the

sample size calculated for the RCT, a type 2 error may be responsible for some of the non-significant findings.

5.

Conclusion

In individuals with PFOA, prefabricated arch contouring foot orthoses produce immediate biomechanical changes at the ankle when compared to a flat insert or the participants’ own shoes during level-walking and stair descent. However, these changes were not accompanied by immediate

ro of

changes in knee pain and confidence. This suggests that changes in distal biomechanics induced by

-p

foot orthoses may not drive therapeutic effects observed in individuals with PFOA.

Conflict of interest

lP

re

The authors state there are no competing interests to declare.

Contributors

na

JMT recruited and screened the participants, carried out the outcome measures and biomechanical data collection, data entry and analysis, and prepared the manuscript. KC, HBM, NC, and SEM were

ur

involved in the methodological design, data analysis and interpretation, and preparation of the manuscript. KM assisted in methodological design, biomechanical data analysis, and preparation of

Jo

the manuscript. HH assisted in the methodological design, biomechanical data collection, and preparation of the manuscript.

Funding sources This study was partially funded by the National Health and Medical Research Council of Australia (ID: 1106852; 2016-2019) and the Discipline of Podiatry at La Trobe University, Melbourne campus

(Bundoora). NJC previously held a University of Queensland Postdoctoral Research Fellowship (2015-2017). HBM is currently a National Health and Medical Research Council Senior Research Fellow (ID: 1135995). Vasyli® Medical (Labrador, Australia) provided a portion of the foot orthoses free of charge. The funding sources have no financial or personal relationship with Vasyli® Medical and therefore the contributions to the study design, analysis and interpretation of data, manuscript, and publication submission by the head of the podiatry discipline are independent. The work of the

ro of

authors was independent of the funders.

Supplementary tables and figures

-p

Fig 1a. Markers needed in static trial to run static gait model (estimate joint centres for Plug in Gait)

re

and participant calibration (create auto labelling for other trials).

Caption. THR2 thoracic 2, THR10 thoracic 10, STRM sternum, RASI right anterior superior

lP

iliac spine, LASI left anterior superior iliac spine, RPSI right posterior superior iliac spine, LPSI left posterior superior iliac spine, RTHI right lateral femur, LTHI left lateral femur, RKD1 right knee alignment device 1, RKAX right knee axis, RKD2 right knee alignment

na

device 2, LKD1 left knee alignment device 1, LKAX left knee axis, LKD2 left knee alignment device 2, RTIB right lateral tibia, LTIB left lateral tibia, RMED right medial

ur

malleoli, LMED left medial malleoli, RANK right ankle, LANK left ankle, RTOE right toe

Jo

(over 2nd metatarsal), LTOE left toe (over 2nd metatarsal), RHEE right heel, LHEE left heel Fig 1b. Markers needed in dynamic trials to run dynamic gait model (calculation of angles from joint centres).

Caption. THR2 thoracic 2, THR10 thoracic 10, STRM sternum, RASI right anterior superior iliac spine, LASI left anterior superior iliac spine, RPSI right posterior superior iliac spine, LPSI left posterior superior iliac spine, RTHI right lateral femur, LTHI left lateral femur,

RKNE right knee, LKNE left knee, RTIB right lateral tibia, LTIB left lateral tibia, RANK right ankle, LANK left ankle, RTOE right toe (over 2nd metatarsal), LTOE left toe (over 2nd metatarsal), RHEE right heel, LHEE left heel

ro of

Acknowledgements The authors wish to thank all participants who volunteered to take part in this study, Vasyli® Medical (Labrador, Australia) for providing a portion of the foot orthoses free of charge, and Sally Coburn for assisting with a portion of the phone screenings and data collection. This study was partially funded

-p

by the National Health and Medical Research Council of Australia (ID: 1106852; 2016-2019) and the

re

Discipline of Podiatry at La Trobe University, Melbourne campus (Bundoora). NJC previously held a University of Queensland Postdoctoral Research Fellowship (2015-2017). HBM is currently a

lP

National Health and Medical Research Council Senior Research Fellow (ID: 1135995). The funding sources have no financial or personal relationship with Vasyli® Medical and therefore the contributions to the study design, analysis and interpretation of data, manuscript, and publication

na

submission by the head of the podiatry discipline are independent. The work of the authors was

Jo

ur

independent of the funders.

References [1] Hart HF, Stefanik JJ, Wyndow N, Machotka Z, Crossley KM. The prevalence of radiographic and MRI-defined patellofemoral osteoarthritis and structural pathology: a systematic review and metaanalysis. Br J Sports Med. 2017;51:1195-208. [2] Hinman R, Crossley K. Patellofemoral joint osteoarthritis: an important subgroup of knee osteoarthritis. Rheumatology (Oxford). 2007;46:1057-62. [3] Kornaat PR, Bloem JL, Ceulemans RY, Riyazi N, Rosendaal FR, Nelissen RG, et al. Osteoarthritis of

ro of

the Knee: Association between Clinical Features and MR Imaging Findings. Radiology. 2006;239:8117.

[4] Collins NJ, Oei EH, de Kanter JL, Vicenzino B, Crossley KM. Prevalence of radiographic and MRI

patellofemoral pain. Arthritis Care Res. 2019;71:1068-73.

-p

features of patellofemoral osteoarthritis in young and middle‐aged adults with persistent

re

[5] Collins NJ, Crossley KM, Beller E, Darnell R, McPoil TG, Vicenzino B. Foot orthoses and

(Clin Res Ed). 2009;43:169-71.

lP

physiotherapy in the treatment of patellofemoral pain syndrome: randomised clinical trial. Br Med J

[6] Lack S, Barton C, Woledge R, Laupheimer M, Morrissey D. The immediate effects of foot orthoses

na

on hip and knee kinematics and muscle activity during a functional step-up task in individuals with patellofemoral pain. Clin Biomech. 2014;29:1056-62.

ur

[7] Stefanyshyn DJ, Hettinga BA. Running injuries and orthotics: review article. ISMJ. 2006;7:109-19. [8] Hertel J, Sloss BR, Earl JE. Effect of foot orthotics on quadriceps and gluteus medius

Jo

electromyographic activity during selected exercises. Arch Phys Med Rehabil. 2005;86:26-30. [9] Wyndow N, Collins NJ, Vicenzino B, Tucker K, Crossley KM. Is There a Biomechanical Link Between Patellofemoral Pain and Osteoarthritis? A Narrative Review. Sports Med. 2016;46:1797-808. [10] Tan JM, Crossley KM, Vicenzino B, Menz HB, Munteanu SE, Collins NJ. Age-related differences in foot mobility in individuals with patellofemoral pain. J Foot Ankle Res. 2018;11.

[11] Tan JM, Menz HB, Crossley KM, Munteanu SE, Hart HF, Middleton KJ, et al. The efficacy of foot orthoses in individuals with patellofemoral osteoarthritis: a randomised feasibility trial. Pilot Feasibility Stud. 2019;5. [12] Collins NJ, Tan JM, Menz HB, Russell TG, Smith AJ, Vicenzino B, et al. The FOOTPATH Study: protocol for a multicentre, participant- and assessor-blind, parallel group randomised clinical trial of foot orthoses for patellofemoral osteoarthritis. BMJ open. 2019;9. [13] Barton CJ, Bonanno D, Menz HB. Development and evaluation of a tool for the assessment of

ro of

footwear characteristics. J Foot Ankle Res. 2009;2:1-12. [14] Redmond AC, Crane YZ, Menz HB. Normative values for the Foot Posture Index. J Foot Ankle Res. 2008;1:1-6.

-p

[15] Konor MM, Morton S, Eckerson JM, Grindstaff TL. Reliability of three measures of ankle dorsiflexion range of motion. Int J Sports Phys Ther. 2012;7:279-87.

re

[16] McPoil TG, Vicenzino B, Cornwall MW, Collins N, Warren M. Reliability and normative values for the foot mobility magnitude: a composite measure of vertical and medial-lateral mobility of the

lP

midfoot. J Foot Ankle Res. 2009;2:6.

[17] Roos EM, Roos HP, Lohmander LS, Ekdahl C, Beynnon BD. Knee Injury and Osteoarthritis

na

Outcome Score (KOOS) - development of a self-administered outcome measure. J Orthop Sports Phys Ther. 1998;28:88-96.

ur

[18] Kujala UM, Jaakkola LH, Koskinen SK, Taimela S, Hurme M, Nelimarkka O. Scoring of patellofemoral disorders. Arthroscopy. 1993;9:159-63.

Jo

[19] Crossley KM, Bennell KL, Cowan SM, Green S. Analysis of outcome measures for persons with patellofemoral pain: which are reliable and valid? Arch Phys Med Rehabil. 2004;85:815-22. [20] Kadaba MP, Ramakrishnan H, Wootten M. Measurement of lower extremity kinematics during level walking. J Orthop Res. 1990;8:383-92. [21] Barton CJ, Levinger P, Menz HB, Webster KE. Kinematic gait characteristics associated with patellofemoral pain syndrome: a systematic review. Gait Posture. 2009;30:405-16.

[22] Fok LA, Schache AG, Crossley KM, Lin YC, Pandy MG. Patellofemoral joint loading during stair ambulation in people with patellofemoral osteoarthritis. Arthritis Rheum. 2013;65:2059-69. [23] Hopkins WG. Measures of reliability in sports medicine and science. Sports Med. 2000;30:1-15. [24] Wyndow N, Collins NJ, Vicenzino B, Tucker K, Crossley KM. Foot and ankle characteristics and dynamic knee valgus in individuals with patellofemoral osteoarthritis. J Foot Ankle Res. 2018;11:65. [25] Mills K, Blanch P, Chapman AR, McPoil TG, Vicenzino B. Foot orthoses and gait: a systematic review and meta-analysis of literature pertaining to potential mechanisms. Br J Sports Med.

ro of

2010;44:1035-46. [26] McCormick CJ, Bonanno DR, Landorf KB. The effect of customised and sham foot orthoses on plantar pressures. J Foot Ankle Res. 2013;6:19-33.

-p

[27] Lack S, Barton C, Malliaras P, Twycross-Lewis R, Woledge R, Morrissey D. The effect of anti-

pronation foot orthoses on hip and knee kinematics and muscle activity during a functional step-up

re

task in healthy individuals: A laboratory study. Clin Biomech. 2014;29:177-82. [28] Matthews M, Rathleff MS, Claus A, McPoil T, Nee R, Crossley K, et al. Can we predict the

lP

outcome for people with patellofemoral pain? A systematic review on prognostic factors and treatment effect modifiers. Br J Sports Med. 2017;51:1650-60.

na

[29] Collins NJ, Hinman RS, Menz HB, Crossley KM. Immediate effects of foot orthoses on pain during functional tasks in people with patellofemoral osteoarthritis: A cross-over, proof-of-concept study.

ur

Knee. 2017;24:76-81.

[30] Jack K, McLean SM, Moffett JK, Gardiner E. Barriers to treatment adherence in physiotherapy

Jo

outpatient clinics: a systematic review. Man Ther. 2010;15:220-8.

Fig 1. Prefabricated full-length Vasyli® foot orthosis (top) and flat shoe insert (bottom).

lP

re

-p

ro of

Fig 1. Prefabricated full-length Vasyli® foot orthosis (top) and flat shoe insert (bottom).

Fig 2. Ankle kinematics: level-walking.

na

Caption. *p<0.001

Jo

ur

Fig 2. Ankle kinematics: level-walking.

Dorsiflexion Plantarflexion Angle (°)

20

*

15 10 5 0 -5

0

20

40

60

80

100

-10 -15 -20

100% Stance Flat inserts

Foot orthoses

ro of

Shoe alone

Jo

ur

na

lP

re

-p

*p<0.001

Tables and figures Table 1. Participant characteristics.

2 (9.5) 2 (9.5) 17 (81.0) 3 (1 to 7) 9.1 (3.2) 8.8 (5.2) 8.9 (3.1) 14.8 (7.9) 40 (22) 55 (30) 50 (17)

ro of

Age (years) Sex (female), n (%) BMI (kg/m2) Right knee affected, n (%) Duration of pain 3 to 6 months, n (%) 6 to 12 months, n (%) 1 to 2 years, n (%) Greater than 2 years, n (%) FPI^§ Weight bearing ankle joint dorsiflexion ROM (cm)^ Arch height difference (mm)^ Midfoot width difference (mm)^ Foot mobility magnitude (mm)^ Usual pain VAS (0 to 100mm) Worst pain VAS (0 to 100mm) AKPS (0 to 100)

Total group (N=21) 58 (8) 14 (67) 27.0 (4.8) 13 (62)

na

lP

re

-p

Values are reported as means (SD) unless otherwise specified. ^ Values are reported for the most symptomatic side. § median (range). BMI body mass index; FPI Foot Posture Index (-12: highly supinated to +12: highly pronated); ROM Range of motion; mm = millimeters; VAS visual analogue scale (0mm = no pain; 100 mm worst pain possible); AKPS Anterior Knee Pain Scale (0 = worst score; 100 = best score).

Jo

ur

Table 1. Participant characteristics.

f oo pr

Table 2. Lower limb biomechanics during level-walking.

Knee

Pr

Hip Peak flexion angle – stance (°) Peak extension angle – stance (°) Peak flexion moment – stance (Nm/kg)

na l

Peak flexion angle – early stance (°) Peak flexion moment – early stance (Nm/kg)§ Peak adduction moment – early stance (Nm/kg)§ Peak adduction moment – late stance (Nm/kg)§ Ankle

Peak dorsiflexion angle – stance (°) Peak dorsiflexion moment – stance (Nm/kg)

Jo ur

Foot orthoses (n=21)

Flat inserts (n=21)

Shoe alone (n=21)

ANOVA/2

47.6 (6.6) -2.1 (8.5) 1.30 (0.27)

47.4 (6.5) -2.4 (8.6) 1.37 (0.43)

47.6 (6.3) -2.2 (8.9) 1.39 (0.44)

F=0.026, df=2, p=0.829 F=0.235, df=2, p=0.153 F=0.069, df=2, p=0.607

23.0 (7.8) 0.58 (0.23) 0.69 (0.23) 0.30 (0.26)

23.1 (6.8) 0.62 (0.33) 0.66 (0.38) 0.29 (0.29)

22.8 (7.1) 0.58 (0.25) 0.66 (0.27) 0.29 (0.28)

F=0.022, df=2, p=0.857 2=0.375, df=2, p=0.829 2=0.875, df=2, p=0.646 2=1.125, df=2, p=0.570

13.3 (3.4)†‡ 0.15 (0.28) ‡

15.1 (3.3) 0.16 (0.27)

14.9 (3.2) 0.15 (0.27)

F=0.773, df=2, p<0.001* F=0.356, df=2, p=0.046*

e-

Table 2. Lower limb biomechanics during level-walking.

Values are reported as mean (SD) unless otherwise stated § median (interquartile range) * significant main effect † significantly different to shoe only condition, Bonferroni post-hoc test ‡ significantly different to flat insert condition, Bonferroni post-hoc test Stance (0 to 100%); early stance (≥0% to <50%); late stance (≥50% to ≤100%) Positive values = flexion and dorsiflexion; negative values = extension and plantarflexion Moments are reported as external

f oo

e-

pr

Table 3. Lower limb biomechanics during stair ascent and descent.

Pr

Table 3. Lower limb biomechanics during stair ascent and descent.

Jo ur

na l

Stair Ascent Hip Peak flexion angle – stance (°) Minimum flexion angle – stance (°) Peak flexion moment – stance (Nm/kg) Knee Peak flexion angle – early stance (°) Peak flexion moment – early stance (Nm/kg) Peak adduction moment – early stance (Nm/kg) Peak adduction moment – late stance (Nm/kg) Ankle Peak dorsiflexion angle – stance (°) Peak dorsiflexion moment – stance (Nm/kg) Stair descent Hip Peak flexion angle – stance (°)

ANOVA / 2

Foot orthoses

Flat inserts

Shoe alone

(n=12)

(n=12)

(n=12)

75.4 (8.3) 18.7 (6.1) 0.70 (0.11)

74.9 (8.6) 17.9 (6.2) 0.66 (0.09)

75.2 (8.7) 18.1 (6.0) 0.67 (0.13)

F=0.350, df=2, p=0.221 F=0.261, df=2, p=0.346 F=0.434, df=2, p=0.136

74.5 (5.1) 0.69 (0.08) 0.72 (0.21) 0.54 (0.12)

74.1 (5.3) 0.72 (0.05) 0.70 (0.19) 0.58 (0.13)

74.5 (5.9) 0.69 (0.05) 0.69 (0.18) 0.54 (0.14)

F=0.144, df=2, p=0.580 F=0.147, df=2, p=0.573 F=0.439, df=2, p=0.132 F=0.234, df=2, p=0.393

21.6 (3.6) 1.31 (0.16) (n=14)

22.3 (4.5) 1.30 (0.19) (n=14)

22.0 (4.2) 1.30 (0.21) (n=14)

F=0.082, df=2, p=0.741 F=0.028, df=2, p=0.904

31.4 (9.1)

31.1 (9.2)

31.0 (9.2)

F=0.127, df=2, p=0.665

19.6 (7.0) 0.39 (0.16)

20.2 (9.2) 0.55 (0.33)

f

19.7 (10.2) 0.46 (0.25)

F=0.242, df=2, p=0.435 F=0.089, df=2, p=0.756

Peak flexion angle – early stance (°) Peak flexion moment – early stance (Nm/kg) Peak adduction moment – early stance (Nm/kg) Peak adduction moment – late stance (Nm/kg)§

25.5 (6.3) 0.39 (0.23) 0.52 (0.21) 0.39 (0.26)

24.0 (3.7) 0.37 (0.22) 0.51 (0.17) 0.37 (0.18)

24.7 (6.3) 0.39 (0.26) 0.46 (0.12) 0.38 (0.17)

F=0.289, df=2, p=0.426 F=0.251, df=2, p=0.420 F=0.259, df=2, p=0.407 2=1.000, df=2, p=0.607

9.9 (4.6) 1.04 (0.23)

9.4 (5.1) 1.16 (0.20)

9.7 (4.4) 1.08 (0.22)

F=0.607, df=2, p=0.097 F=0.823, df=2, p=0.006*^

oo

Minimum flexion angle – stance (°) Peak flexion moment – stance (Nm/kg)

pr

Knee

Ankle

e-

Peak dorsiflexion angle – stance (°) Peak dorsiflexion moment – stance (Nm/kg)

Jo ur

na l

Pr

Values are reported as mean (SD) unless otherwise stated § median (interquartile range) * significant main effect ^ No difference between groups after Bonferroni post-hoc test Stance (0 to 100%); early stance (≥0% to <50%); late stance (≥50% to ≤100%) Positive values = flexion and dorsiflexion; negative values = extension and plantarflexion Moments are reported as external

Table 4. Baseline pain and confidence during laboratory-based testing.

na l

Pr

e-

pr

oo

f

Table 4. Baseline pain and confidence during laboratory-based testing Foot Flat Shoes Foot orthoses Foot orthoses versus Flat inserts versus shoe orthoses inserts only versus flat inserts shoe alone alone Knee pain VAS Mean difference (95% confidence interval) (0 to 100 mm) Level 17 (20) 21 (24) 22 (23) 4.2 (-2.9 to 11.2) 4.6 (-3.1 to 12.3) 0.4 (-6.7 to 7.6) walking Stair ascent 23 (19) 20 (14) 26 (16) -3.4 (-13.1 to 6.3) 2.3 (-5.3 to 9.9) 5.7 (-0.4 to 11.8) Stair 25 (20) 26 (19) 28 (22) 0.7 (-11.5 to 12.9) 3.5 (-8.8 to 15.7) 2.8 (-9.0 to 14.5) descent Knee confidence VAS (0 to 100 mm) Level 19 (17) 13 (13) 15 (18) -6.6 (-16.1 to 2.8) -4.3 (-13.8 to 5.2) 2.3 (-7.5 to 12.0) walking Stair ascent 24 (23) 19 (16) 23 (18) -5.2 (-13.9 to 3.4) -0.6 (-17.1 to 15.8) 4.6 (-8.5 to 17.7) Stair 25 (21) 27 (23) 27 (22) 2.8 (-12.5 to 18.1) 2.2 (-11.6 to 16.0) -0.6 (-11.3 to 10.0) descent

Jo ur

Values are reported as mean (SD) unless otherwise stated *p<0.05 VAS = visual analogue scale (0 = no pain/very confident; 100 = worst pain possible/not confident at all); mm = millimeter Number of participants during level-walking (n=18) and stair ambulation (n=17)

ANOVA

F= 1.517, df=2, p=0.249 F= 3.260, df=2, p=0.067 F= 0.310, df=2, p=0.738

F= 1.692, df=2, p=0.216 F= 1.828, df=2, p=0.195 F= 0.118, df=2, p=0.890