The Effect of Physical Activity on Knee Osteoarthritis, Pain and Gait

The Effect of Retro Walking on Pain and Gait Biomechanics Using Non-linear Analysis in People With Knee Osteoarthritis

Knee osteoarthritis, a chronic musculoskeletal disease, is the most prevalent type of osteoarthritis and the leading cause of disability and major healthcare costs worldwide. The pathogenesis of the disease is not fully understood and there are few non-invasive disease-modifying therapies available to patients. Therefore, there is a critical need to enhance therapeutic interventions, which requires improvement of our understanding of knee osteoarthritis pathogenesis.

Increasing evidence suggests that physical activity and exercise training are cost-effective and widely available interventions for the treatment of knee osteoarthritis, however, consideration of type of physical activity and optimal exercise modality are needed to reduce pain, improve gait, knee joint function, stiffness, and muscle weakness in individuals with knee osteoarthritis.

The aim of this pilot clinical trial is to compare individuals with knee osteoarthritis who have not exercised with individuals that have performed retro walking exercise chosen from the systematic review and survey we have conducted previously to reduce pain and improve gait.

Non-linear analyses will be performed to determine the effects of exercise intervention on gait biomechanics and stability of movement in these patients. These findings may form a basis for recommendations of exercise/physical activity interventions for the benefits of patients with knee osteoarthritis including pain reduction, mobility improvement and gait modification.

Study Overview

• Status: Not yet recruiting
• Conditions: Osteoarthritis (OA) of the Knee
• Intervention / Treatment: Other: Retro walking (backwards walking) on a treadmill

• Study Type: Interventional
• Enrollment (Estimated): 44
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Hasmik J Samvelyan, PhD; Phone Number: +441245683738; Email: jasmine.samvelyan@aru.ac.uk
• Study Contact Backup: Name: Nathan Bytheway, MEng; Email: NB941@pgr.aru.ac.uk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Male and female
• Any ethnicity
• Adults over 18 years old
• Meet the UK guidelines for physical activity supported by NICE (National Institute for Health and Care Excellence) and NHS (able to exercise if it is safe with regular breaks)
• Otherwise, adults with clinically diagnosed knee osteoarthritis according to NICE criteria or confirmed by a healthcare professional able and willing to participate and provide written informed consent

Exclusion Criteria:

• Any musculoskeletal injury
• Any conditions known to affects gait (e.g. Parkinson's disease or stroke)
• Any surgical intervention in the previous 12 months on lower limbs
• Surgical replacement of hip or knee joints
• BMI (body mass index) over 35
• Athletes or take part in significant recreational activity
• Takes any medication known to affect the gait and ability to walk
• Received an intra-articular injection in the last 3 months
• Have been told by medical professionals that they should not take part in any intensity exercise/physical activity

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Exercise; Participants in the intervention group will perform treadmill retro walking exercise 3 days/week for 6 weeks.	Other: Retro walking (backwards walking) on a treadmill; Prior to the intervention participants will be made familiar with retro walking on the treadmill. The exercise will consist of a forward walking for 5min on the treadmill for warm-up followed by retro walking for 10min and a cool-down for 5min. Participants will be instructed to increase their retro walking time up to 30min if the pain sensation continuously was reduced (pain scores < 3 numerical rating scale). The comfortable speed of the retro walking will be determined by the participant under supervision of the researchers. No slopes or inclination will be used in this study for participant safety. In the warm-up and cool-down sessions participants will be asked to perform muscle stretch, ankle toe movements and heel raise exercises.; Other Names: Exercise
No Intervention: Control; Participants in the control group will maintain their existing level of activity.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Knee function and associated frequency and severity of pain	Participants' opinion about their own knee function and associated problems will be assessed through self-administered and validated questionnaire Knee Injury and Osteoarthritis Outcome Score (KOOS). KOOS questionnaire designed to collectively evaluate and measure five outcomes in individuals with knee osteoarthritis including: Pain: Frequency and severity of knee pain. Symptoms: Swelling, grinding, stiffness, and range of motion issues. Activities of Daily Living (ADL): Difficulty with physical tasks like stairs, rising from a seat, or getting in and out of a car. Sports and Recreation Function: The ability to perform higher-level physical activities, such as running, squatting, or playing sports. Quality of Life (QOL): Knee-related lifestyle limitations and personal awareness of the joint.	Baseline or Day 1 and end of study at 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain intensity	A standardised tool numeric pain rating scale (NPRS) will be used to measure a participants' pain intensity. It is an 11-point scale ranging from 0 to 10. 0: Represents "no pain" whereas 10: Represents the "worst imaginable pain". Participants can state their number verbally or circle it on a chart.	Baseline or Day 1 up to 6 weeks
The gait biomechanics - change from baseline in spatiotemporal parameter walking speed at 6 weeks	Spatiotemporal parameter walking speed (velocity, meters/sec) will be assessed using VICON motion capture analysis system.	Baseline or Day 1 and end of study at 6 weeks
The gait biomechanics - change from baseline in spatiotemporal parameter cadence at 6 weeks	Spatiotemporal parameter cadence (steps/min) will be assessed using VICON motion capture analysis system.	Baseline or Day 1 and end of study at 6 weeks
The gait biomechanics - change from baseline in spatiotemporal parameter stride/step length at 6 weeks	Spatiotemporal parameter stride/step length (meters or cm) will be assessed using VICON motion capture analysis system.	Baseline or Day 1 and end of study at 6 weeks
The gait biomechanics - change from baseline in spatiotemporal parameter swing/stance phases at 6 weeks	Spatiotemporal parameter swing/stance phases (% of gait cycle) will be assessed using VICON motion capture analysis system.	Baseline or Day 1 and end of study at 6 weeks
The gait biomechanics - change from baseline in spatiotemporal parameter double support time at 6 weeks	Spatiotemporal parameter double support time (% of gait cycle) will be assessed using VICON motion capture analysis system.	Baseline or Day 1 and end of study at 6 weeks
The gait biomechanics - change from baseline in kinetic parameter knee adduction moment (KAM) at 6 weeks	Kinetic parameter knee adduction moment (KAM) (Newton meters Nm) will be assessed using VICON motion capture analysis system.	Baseline or Day 1 and end of study at 6 weeks
The gait biomechanics - change from baseline in kinetic parameter knee flexion/extension moment at 6 weeks	Kinetic parameter knee flexion/extension moment (Newton meters Nm) will be assessed using VICON motion capture analysis system.	Baseline or Day 1 and end of study at 6 weeks
The gait biomechanics - change from baseline in kinetic parameter vertical ground reaction force (vGRF) at 6 weeks	Kinetic parameter vertical ground reaction force (vGRF) (Newtons N) will be assessed using VICON motion capture analysis system.	Baseline or Day 1 and end of study at 6 weeks
The gait biomechanics - change from baseline in kinetic parameter joint contact force (JCF) at 6 weeks	Kinetic parameter joint contact force (JCF) (Newtons N) will be assessed using VICON motion capture analysis system.	Baseline or Day 1 and end of study at 6 weeks
The gait biomechanics - change from baseline in kinematic parameter knee flexion angle at 6 weeks	Kinematic parameter knee flexion angle (Degrees (°)) will be assessed using VICON motion capture analysis system.	Baseline or Day 1 and end of study at 6 weeks
The gait biomechanics - change from baseline in kinematic parameter Range of Motion (ROM) at 6 weeks	Kinematic parameter Range of Motion (ROM) (Degrees (°)) will be assessed using VICON motion capture analysis system.	Baseline or Day 1 and end of study at 6 weeks
The gait biomechanics - change from baseline in kinematic parameter knee adduction/abduction at 6 weeks	Kinematic parameter knee adduction/abduction (Degrees (°)) will be assessed using VICON motion capture analysis system.	Baseline or Day 1 and end of study at 6 weeks
Gait stability	The stability of walking will be measured using non-linear analysis including Lyapunov (1/s or s^(-1)) and Hurst Exponents.	Baseline or Day 1 and end of study at 6 weeks

Collaborators and Investigators

• Sponsor: Anglia Ruskin University
• Collaborators: Cambridge University Hospitals NHS Foundation Trust; Nuffield Health

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: May 18, 2026
• First Submitted That Met QC Criteria: June 11, 2026
• First Posted (Actual): June 16, 2026

Study Record Updates

• Last Update Posted (Actual): June 16, 2026
• Last Update Submitted That Met QC Criteria: June 11, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Arthritis; Joint Diseases; Rheumatic Diseases; Osteoarthritis; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Exercise
• Other Study ID Numbers: 356992

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No