Condition category
Musculoskeletal Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status

Plain English Summary

Background and study aims
Knee osteoarthritis (OA) is a condition that causes the knees to become painful and stiff. It is strongly affected by the way in which the knee joint is loaded during activities (i.e., the force put on the knee joint). Previous studies have found that footwear which alters the loading at the knee joint can reduce the pain. However, to date there has been relatively little research investigating the potential effects of rocker shoes. These shoes have a curved sole and are designed to rock the foot forward when walking. This rocking action may change the way in which the muscles of the leg activate and this may bring about a corresponding change in the way the joint is loaded. Before undertaking a large study, it is important to understand the effects of rocker footwear. Therefore, this study has been designed to find out how this type of footwear changes muscle activation patterns and how it may impact on joint loading in both individuals with knee osteoarthritis and healthy volunteers.

Who can participate?
Knee osteoarthritis patients and healthy volunteers aged between 40-85.

What does the study involve?
Each participant attends a single laboratory testing session at the University of Salford, during which they will wear different types of footwear (i.e., rocker footwear and a flexible OA shoe) whilst muscle activation and 3D motion data is collected.

What are the possible benefits and risks of participating?
Participants will experience different types of footwear, but we do not expect this to provide any significant benefits to participants. We are able to provide participants with travel expenses for participating. There are no risks of participating.

Where is the study run from?
University of Salford (UK)

When is the study starting and how long is it expected to run for?
November 2015 to November 2017

Who is funding the study?
University of Salford (UK)

Who is the main contact?
Ali Algarni

Trial website

Contact information



Primary contact

Dr Stephen Preece


Contact details

Centre for Health Sciences Research
Blatchford Building
Stratham Street
M6 6PU
United Kingdom
+44 (0)161 295 2273

Additional identifiers

EudraCT number number

Protocol/serial number

Protocol v2

Study information

Scientific title

The biomechanical effect of rocker shoes in people with knee osteoarthritis: a randomised cross-over trial


Study hypothesis

This study will therefore compare the biomechanical effect of this specific design of rocker shoe, with both a flexible shoe and also a standard control shoe.

Ethics approval

UK NHS ethics committee of East Midlands - Derby, 17/11/2015, REC ref: 15/EM/0502

Study design

Randomised cross-over trial

Primary study design


Secondary study design

Randomised cross over trial

Trial setting


Trial type


Patient information sheet

Not available in web format. Please use the contact details below to request a patient information sheet.


Knee osteoarthritis


Single-centre trial in which we plan to investigate the biomechanical effects of different footwear. This will be achieved with a laboratory cross-over study at the University of Salford, during which participants will wear the different types of footwear (rocker footwear and a flexible OA shoe) during a single testing session whilst biomechanical data (muscle activation and 3D motion) is collected.

Intervention type



Drug names

Primary outcome measures

Muscular co-contraction of the quadriceps and hamstrings and the quadriceps and gastrocnemius, derived from electromyography (EMG) data collected from the specified muscles during walking

Secondary outcome measures

1. The knee extensor moment outcome calculated from force and kinematic (3D motion) data collected during walking
2. The centre of mass position derived from full-body 3D motion data during walking

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Age range 40-85 (upper age limit due to the amount of walking involved in the study)
2. Ability to stand and walk independently
3. Speak and understand written English
4. Ability to walk without any walk assistive for at least 250 m
5. Clinical diagnosis of knee OA according to American College of Rheumatology (ACR) (Altman et al. 1986) (if they are a participant with knee OA)
6. Pain for at least 6 months' duration (if they are a participant with knee OA)
7. Pain or difficulty in rising from sitting and/or climbing stairs (if they are a participant with knee OA)

Participant type


Age group




Target number of participants

30 with OA and 30 healthy volunteers

Participant exclusion criteria

1. Complex pain conditions such as diabetic neuropathic pain, fibromyalgia
2. Have had previous surgery to the lower limb
3. BMI >33 since it is not possible to perform accurate measurements on individuals with excess adipose tissue
4. Lower limb arthroplasty
5. Any systemic inflammatory disorders, such as rheumatoid arthritis
6. Any balance disorders which may increase the risk of a fall

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

University of Salford
Centre for Health Sciences Research Blatchford Building University of Salford Salford
M6 6PU
United Kingdom

Sponsor information


University of Salford (UK)

Sponsor details

Allerton Building
University of Salford
M6 6PU
United Kingdom

Sponsor type

Research organisation



Funder type


Funder name

University of Salford (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

The results will be submitted for publication in biomechanics and osteoarthritis journals

Intention to publish date

Participant level data

Not expected to be available

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes