Determining the effect of feedback-based and dual-task exercises on lower limb biomechanical patterns in military personnel with patellofemoral pain syndrome.
Design
This research is of an applied type and is conducted with an experimental approach and a randomized controlled trial design with parallel groups and a pre-test-post-test design.
The study population of this research will be practically limited to active military personnel and male armed forces soldiers aged 20 to 35, with a height of 165 to 185 and a weight of 65 to 85 kg in Quchan County, whom the researcher has access to.
Participants are assigned to two feedback and dual-task groups using a Random Number Generator. Coding and maintenance of the random list is performed by an independent person to reduce the possibility of bias.
Settings and conduct
The study area is the rehabilitation of individuals with PFPS in Quchan city. The intervention includes two groups of subjects (feedback group and dual task group), each of which is subject to its own specific training program. The intervention period is 6 weeks, with 3 sessions held each week. Each session is 45 minutes long, and will include warm-up, main exercises, and cool-down, respectively.
Participants/Inclusion and exclusion criteria
Clinical diagnosis of PFPS by a specialist based on MRI images
Ability to perform basic independent activities (with or without assistive devices such as crutches)
No severe neurological disease or other musculoskeletal problems (such as severe knee osteoarthritis) that would interfere with the intervention
No history of knee surgery in the past 6 months
Intervention groups
Feedback-Based Training
Dual-Task Training
Main outcome variables
Knee valgus angle; Dynamic balance; Lower limb neuromuscular coordination; Pain intensity; Quadriceps and hamstring strength
General information
Reason for update
Acronym
PFPS
IRCT registration information
IRCT registration number:IRCT20260511069346N1
Registration date:2026-06-03, 1405/03/13
Registration timing:registered_while_recruiting
Last update:2026-06-03, 1405/03/13
Update count:0
Registration date
2026-06-03, 1405/03/13
Registrant information
Name
mojtaba khoshbaten
Name of organization / entity
Country
Iran (Islamic Republic of)
Phone
+98 51 4725 9005
Email address
mj.khoshbaten@gmail.com
Recruitment status
Recruitment complete
Funding source
Expected recruitment start date
2026-05-12, 1405/02/22
Expected recruitment end date
2026-06-10, 1405/03/20
Actual recruitment start date
empty
Actual recruitment end date
empty
Trial completion date
empty
Scientific title
Comparison of Feedback-Based and Dual-Task Training on Lower Limb Biomechanics inMilitary Personnel with Patellofemoral Pain Syndrome
Public title
Comparison of two types of exercises on knee pain in military personnel
Purpose
Treatment
Inclusion/Exclusion criteria
Inclusion criteria:
Clinical diagnosis of PFPS by a specialist based on MRI
Ability to perform basic independent activities (with or without assistive devices such as canes)
Absence of severe neurological diseases (such as stroke or Parkinson's) or other musculoskeletal problems (such as severe knee osteoarthritis) that would interfere with the intervention
No history of knee surgery in the past 6 months.
Exclusion criteria:
Presence of severe neurological disorders such as stroke or Parkinson’s disease
Presence of musculoskeletal disorders affecting knee function, such as severe knee osteoarthritis
History of knee surgery within the past 6 months
Medical contraindication to participation in exercise or rehabilitation interventions
Inability to perform basic independent activities, even with assistive devices
Lack of confirmed diagnosis of patellofemoral pain syndrome (PFPS) based on MRI and specialist evaluation
Age
From 20 years old to 35 years old
Gender
Male
Phase
N/A
Groups that have been masked
No information
Sample size
Target sample size:
44
Randomization (investigator's opinion)
Randomized
Randomization description
Participants are assigned to two feedback and dual-task groups using a Random Number Generator. Coding and maintenance of the random list is performed by an independent person to reduce the possibility of bias.
Blinding (investigator's opinion)
Not blinded
Blinding description
Placebo
Not used
Assignment
Parallel
Other design features
Secondary Ids
empty
Ethics committees
1
Ethics committee
Name of ethics committee
Research Ethics Committees of Baqiyatullah Hospital
Street address
Sheykh Bahayi st., Mollasadra st., Vanak Sq.,
City
Tehran
Province
Tehran
Postal code
1435915381
Approval date
2026-02-02, 1404/11/13
Ethics committee reference number
IR.BMSU.BAQ.REC.1404.141
Health conditions studied
1
Description of health condition studied
Patellofemoral pain syndrome
ICD-10 code
M22.2
ICD-10 code description
Patellofemoral disorders
Primary outcomes
1
Description
Pain by visual analog scale
Timepoint
6 week
Method of measurement
VAS Questionnaire
Secondary outcomes
empty
Intervention groups
1
Description
Feedback-Based Training: Feedback training is a neuromuscular intervention that uses real-time visual, auditory, or combined feedback to correct abnormal movement patterns. In individuals with Patellofemoral Pain Syndrome, this approach aims to reduce dynamic knee valgus, improve hip and knee joint control, and optimize mechanical load distribution across the patellofemoral joint. During the intervention, participants perform functional movements such as squats, stair ascent, and stair descent while receiving immediate feedback to correct lower-limb alignment and movement quality.The equipment used in this intervention includes a full-length mirror for visual feedback, an interactive video projector to display correct movement patterns, a Kinect camera for real-time motion capture and display, and Kinovea software for biomechanical motion analysis. Additional training equipment includes resistance bands (TheraBand), light ankle weights ranging from 0.5 to 2 kg, adjustable aerobic steps, exercise mats, and balance foam pads.The intervention program lasts for six weeks and consists of three sessions per week, for a total of 18 sessions. Each session lasts approximately 45 minutes. Before the intervention begins, participants attend a 60-minute introductory session that includes explanation of the study objectives, instruction on proper exercise execution, familiarization with the feedback devices, practice of basic movements, and education regarding pain-monitoring and exercise termination criteria.Each training session begins with a 5–7 minute warm-up consisting of light walking, hip-knee-ankle mobility exercises, and dynamic stretching of the quadriceps, hamstrings, and calf muscles. The main training section lasts approximately 30 minutes and includes exercises such as mini squats, wall squats, step-ups, step-downs, single-leg squats, and sit-to-stand tasks. While performing these exercises, participants observe their knee and hip alignment in the mirror, receive verbal corrections from the therapist, and in selected sessions view live movement feedback through the Kinect system.Training initially starts with 3 sets of 10 repetitions with 30–60 seconds of rest between sets. Exercises are performed within a pain-free or minimally painful range (VAS < 3). As participants progress, repetitions are increased to 15–20, resistance bands are added, squat depth is increased, and some exercises are performed on unstable surfaces.Visual feedback is provided through direct observation of lower-limb alignment in the mirror and through movement-angle analysis using Kinovea software. Auditory feedback is provided by the therapist using verbal cues such as “keep the knee aligned,” “stabilize the pelvis,” and “distribute your weight evenly.” Throughout the intervention, faded feedback principles are applied. In the early sessions, feedback is provided continuously, but over time the amount of verbal correction is gradually reduced to encourage self-monitoring and automatic motor control.
Category
Rehabilitation
2
Description
Dual-Task Training: Dual-task training is a rehabilitation approach in which participants simultaneously perform a motor task and a cognitive task. This intervention is designed to improve cognitive-motor integration, postural control, and movement automaticity during functional activities. In individuals with Patellofemoral Pain Syndrome, impaired motor control and increased attentional demands may contribute to pain and functional instability. Therefore, dual-task exercises are used to improve movement performance under conditions that more closely resemble daily-life activities.The equipment used for this intervention includes an interactive video projector, a Kinect motion sensor, balance boards, foam balance pads, cones and movement markers, a digital timer, cognitive-task presentation software, and speakers for auditory instructions.The intervention lasts for six weeks with three sessions per week, resulting in a total of 18 sessions. Each session lasts approximately 45 minutes. Prior to the intervention, participants attend a 60-minute familiarization session in which they are introduced to the basic motor exercises, cognitive tasks, and the Kinect and projector systems.Each session begins with a 5–7 minute warm-up including light walking, simple balance activities, and dynamic stretching exercises. The main training component lasts approximately 30 minutes and combines motor and cognitive activities simultaneously.Motor tasks include line walking, single-leg standing, controlled squatting, weight-shifting activities, and exercises performed on unstable surfaces. Cognitive tasks performed concurrently include backward counting, color naming, responding to visual stimuli, solving simple arithmetic problems, and short-term memory exercises such as number repetition.Training initially begins with 3 sets of 1-minute dual-task exercises with 30–60 seconds of rest between sets. As participants improve, the duration of the exercises is increased to 2–3 minutes, cognitive-task complexity is progressively increased, unstable surfaces are introduced, and additional visual or auditory stimuli are added to increase attentional demands.Throughout the intervention, pain intensity and fatigue are continuously monitored. Exercises are stopped if participants experience excessive pain or discomfort, and all activities are performed within a tolerable and safe movement range under therapist supervision.
Category
Rehabilitation
Recruitment centers
1
Recruitment center
Name of recruitment center
Dr.Khoshbaten Corrective Exercise Center
Full name of responsible person
Mojtaba khoshbaten
Street address
Unit 3, No. 16, Nikoei Street
City
Quchan
Province
Razavi Khorasan
Postal code
9471948468
Phone
+98 51 4725 9005
Email
mj.khosbaten@gmail.com
Sponsors / Funding sources
1
Sponsor
Name of organization / entity
Bagheiat-allah University of Medical Sciences
Full name of responsible person
Dr. Hossein Kachuee
Street address
Mollasadra st, Vanak sq Sheykh Bahayi st.
City
Tehran
Province
Tehran
Postal code
1435915381
Phone
+98 21 8804 0060
Email
info@bmsu.ac.ir
Web page address
https://www.bmsu.ac.ir
Grant name
No specific grant
Grant code / Reference number
N/A
Is the source of funding the same sponsor organization/entity?
Yes
Title of funding source
Bagheiat-allah University of Medical Sciences
Proportion provided by this source
100
Public or private sector
Public
Domestic or foreign origin
Domestic
Category of foreign source of funding
empty
Country of origin
Type of organization providing the funding
Academic
Person responsible for general inquiries
Contact
Name of organization / entity
Bagheiat-allah University of Medical Sciences
Full name of responsible person
Hossein Shirvani
Position
Associate Professor of Baqiyatallah University
Latest degree
Ph.D.
Other areas of specialty/work
Physiology
Street address
Sheykh Bahayi st, Mollasadra st, Vanak sq.
City
Tehran
Province
Tehran
Postal code
1435915381
Phone
+98 21 8804 0060
Email
shirvani.h2006@gmail.com
Person responsible for scientific inquiries
Contact
Name of organization / entity
Bagheiat-allah University of Medical Sciences
Full name of responsible person
Hossein Shirvani
Position
Associate Professor of Baqiyatallah University
Latest degree
Ph.D.
Other areas of specialty/work
Physiology
Street address
Sheykh Bahayi st, Mollasadra st, Vanak sq.
City
Tehran
Province
Tehran
Postal code
14359 15371
Phone
+98 21 8755 5000
Email
shirvani.h2006@gmail.com
Person responsible for updating data
Contact
Name of organization / entity
Kharazmi university
Full name of responsible person
Mojtaba Khoshbaten
Position
Assistant Professor, Quchan Azad University
Latest degree
Ph.D.
Other areas of specialty/work
Sports Biomechanics
Street address
Unit 3, Parseh Medical Complex, Nikooei Street
City
Quchan
Province
Razavi Khorasan
Postal code
9471948467
Phone
+98 51 4725 9005
Email
mj.khoshbaten@gmail.com
Sharing plan
Deidentified Individual Participant Data Set (IPD)
Yes - There is a plan to make this available
Study Protocol
Yes - There is a plan to make this available
Statistical Analysis Plan
Yes - There is a plan to make this available
Informed Consent Form
Yes - There is a plan to make this available
Clinical Study Report
Yes - There is a plan to make this available
Analytic Code
Undecided - It is not yet known if there will be a plan to make this available
Data Dictionary
Undecided - It is not yet known if there will be a plan to make this available
Title and more details about the data/document
All documentation will be published in the form of a research article published in a reputable journal.
When the data will become available and for how long
After printing the article
To whom data/document is available
Universities and researchers
Under which criteria data/document could be used
Use for citation or review article
From where data/document is obtainable
Website of the publication that published the article
What processes are involved for a request to access data/document
The application must be official to the Vice Chancellor for Research of Baqiyatallah University of Medical Sciences.