Footwear and Exercise for Knee Osteoarthritis (FiREwORK Trial)

Scored on an 11-point numeric rating scale for average knee pain on walking over the past week, with terminal descriptors of "0=no pain" to "10=worst pain imaginable".

Graded using the MRI Osteoarthritis Knee Score hoffa-synovitis sub-score, ranging grade 0 (normal) to grade 3 (severe).

Graded using the MRI Osteoarthritis Knee Score effusion-synovitis sub-score, ranging grade 0 (physiologic amount) to grade 3 (large - evidence of capsular distention).

Graded using the MRI Osteoarthritis Knee Score bone marrow lesion sub-score, grade 0 (none) to grade 3 (>66% of subregional volume).

Measured with the function subscale of the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index. This sub-scale gives a range of possible scores from "0=no dysfunction" to "68=maximum dysfunction".

Scored on an 11-point numeric rating scale for average knee pain overall the past week, with terminal descriptors of "0=no pain" to "10=worst pain imaginable".

Scored on a 7-point ordinal scale (with terminal descriptors of "1=much worse" to "7=much better"). Participants who report they are "moderately better" and above will be classified as "improved".

Scored on a 7-point ordinal scale (with terminal descriptors of "1=much worse" to "7=much better"). Participants who report they are "moderately better" and above will be classified as "improved".

Scored on a 7-point ordinal scale (with terminal descriptors of "1=much worse" to "7=much better"). Participants who report they are "moderately better" and above will be classified as "improved".

Measured using a pedometer attached to the hip for 7 subsequent days to assess objective physical activity.

Measured using the Physical Activity Scale for the Elderly with scores ranging 0-400 where higher scores indicate greater physical activity.

Measured using the EuroQoL Quality of Life Scale (EQ-5D) with scores ranging from 0 to 100 (higher scores indication better health-related quality of life).

Measured using a shoe-mounted pedometer on week 1, 12 and 37 for 7 consecutive days and by self-report in logbooks for one week during each month. The number of hours of daily shoe wearing will be recorded for 7 consecutive days and compliance will be rated using an 11-point NRS (with terminal descriptors "0=never worn" to "10=always worn").

During the supervised 12-week phase, participants will record completed exercise sessions every week in a logbook and will complete weekly 11-point NRS scales rating their overall compliance with the exercise prescription (with terminal descriptors: "0= not at all compliant" to "10=extremely compliant"). Therapists will record participants' attendance. During the 6-month phase, patient-reported adherence will be collected for one week each month.

will be collected monthly using logbooks and will also be quired by questionnaire.

An 8-camera optical motion capture system and a force plate will be used to collect kinematic and ground reaction forces. Participants will perform barefoot walking trials at a self-selected walking speed until seven complete "clean" foot strikes (satisfactory force plate contact defined as initial contact at the heel and toe off occurring on the force plate)) will be recorded from both limbs. At 36 weeks, participants will perform gait analysis under two conditions (in random order): (i) barefoot and (ii) allocated shoe. Major parameters of interest will be: (i) peak knee adduction moment, (ii) knee adduction moment angular impulse, and (iii) peak knee flexion moment. Unblinded scientific personnel and a blinded PhD student will collect the gait data. At 36 weeks the PhD student will be unblinded during the 3D gait analyses (last test of the testing session). Subsequent analyses will be performed by the blinded PhD student.

Will be measured using an ultrasound machine with a 10-18 MHz linear array transducer. The regions examined will be: the suprapatellar recess, the medial and lateral parapatellar recesses and the medial and lateral femorotibial joint space. All anterior scans will be performed in the longitudinal position except for the parapatellar recess (transverse). Posteriorly, The medial aspect of the popliteal space will be assessed both in the longitudinal and transversal position to assess Baker's cyst presence. All US examinations will be carried out by one unblinded investigator with the participant lying supine on an examination table (knee flexed to 30°), except for the Baker's cyst assessment in which the participant is prone (knee fully extended). The same investigator will evaluate all images for capsular distension, synovial Doppler activity, synovial hypertrophy, effusion and presence of Baker's cyst. The investigator will be blinded to participant ID and test date.

Will be assessed using the modified painDETECT questionnaire (mPDQ) a 12-item patient-based, screening questionnaire to determine the presence of neuropathic pain components validated in a range of conditions including OA.

Will be assessed using the Foot Posture Index (FPI), a valid and reliable tool that scores six features of foot posture from - 2 (more supinated) to + 2 (more pronated).

The Photographic Knee Pain Map will be used to determine location of knee pain. The map consists of a photographic representation of the anterior view of a pair of knees on which the participant can mark all painful locations in their study knee.

Participants who will stop participating in the study (either due to loss to follow-up or study withdrawal) will be asked by mail or telephone to provide the reason why they dropped out from the study. These information will be formally recorded throughout the trial by the trial coordinator.

Will be measured assessing heat detection and pain thresholds on the study knee (i.e., most painful knee) by one (always the same) blinded investigator.Heat contact thermal stimuli will be delivered using a computer-controlled (Medoc Pathway Pain & Sensory Evaluation System).

Will be measured assessing heat detection and pain threshold on a remote peripheral site (i.e., extensor carpi radialis longus) by one (always the same) blinded investigator. Heat contact thermal stimuli will be delivered using a computer-controlled (Medoc Pathway Pain & Sensory Evaluation System).

Will be measured by temporal summation (TS) at the study knee (i.e., most painful knee) performed by one (always the same) blinded investigator. Heat contact thermal stimuli will be delivered using a computer-controlled (Medoc Pathway Pain & Sensory Evaluation System). Heat stimuli will be individualized for each subject. Participants will receive10 heat pulses. Participants will be asked to provide a verbal pain rating on a 11-point (0-10) numeric rating scale (NRS) (0 = no pain and 10 = most intense pain imaginable) at 1st; 5th and 10th pulse. TS will be derived according to established protocols.

Will be measured by temporal summation (TS) on a remote peripheral site (i.e., extensor carpi radialis longus) performed by one (always the same person) blinded investigator. Heat contact thermal stimuli will be delivered using a computer-controlled (Medoc Pathway Pain & Sensory Evaluation System). Heat stimuli will be individualized for each subject. Participants will receive10 heat pulses. Participants will be asked to provide a verbal pain rating on a 11-point (0-10) numeric rating scale (NRS) (0 = no pain and 10 = most intense pain imaginable) at 1st; 5th and 10th pulse. TS will be derived according to established protocols.

Pressure pain thresholds (PPTs) will be performed on the study knee (i.e., most painful knee) by eliciting mechanical pressure pain applied perpendicular to the skin using an analogue algometer. PPTs will be performed by one (always the same person) blinded investigator.

Pressure pain thresholds (PPTs) will be performed on a remote peripheral site (i.e., extensor carpi radialis longus) by eliciting mechanical pressure pain applied perpendicular to the skin using an analogue algometer. PPTs will be performed by one (always the same person) blinded investigator.

Will be assessed by conditioned pain modulation (CPM) at the study knee (i.e., most painful knee) by one (always the same person) blinded investigator. CPM will be measured using a test stimulus followed by a conditioning stimulus and re-assessment of the test stimulus during and after the conditioning stimulus.

Will be assessed by conditioned pain modulation (CPM) on a remote peripheral site (i.e., extensor carpi radialis longus) by one (always the same person) blinded investigator. CPM will be measured using a test stimulus followed by a conditioning stimulus and re-assessment of the test stimulus during and after the conditioning stimulus.

Will be assessed using the central sensitisation inventory (CSI).