Identification of Exercise Components of Core Stability and Their Effectiveness on Foot Posture, Foot Function, and Lower Limb Alignment in Adults With Flexible Flat Feet
Phase: NA
Conditions: Flexible Flatfoot
Sponsor: International Islamic University Malaysia

TITLE: Identification of exercise components of core stability and their effectiveness on foot 
posture, foot function and lower limb alignment in adults with flexible flat feet  
NCT number:  NCT06567509 
IREC ETHICAL APPROVAL NUMBER: IREC 2024-257 
DATE OF DOCUMENT: 16/07/2024 
DOCUMENT TYPE: Study Protocol 
 
BACKGROUND 
Flexible flat feet are a common clinical condition that may influence lower limb alignment and 
proximal joint biomechanics. Conventional foot-focused exercises are commonly prescribed; 
however, their effects may be limited. Emerging perspectives suggest that altered foot posture 
may be influenced by proximal postural and neuromuscular factors, including core musculature 
function. Therefore, this study aimed to examine the effect of core stability exercises on foot 
posture and lower limb alignment in individuals with flexible flat feet 
Objectives 
1. To evaluate the feasibility of core stability training protocol that will be devised in the 
proposed study.  
2. To assess the effect of core stability training on the foot posture in adults with flexible flat 
feet. 
3. To assess the effect of core stability training on lower limb alignment in adults with flexible 
flat foot.  
 
STUDY DESIGN 
 
 Randomized Controlled Trial 
 Allocation:  parallel 
 Number of groups: 2 
 Study duration: December 2024 to January 2026 
 Study was conducted at Department of Physical rehabilitation Sciences, International 
Islamic university of Malaysia, Kuantan, Pahang, Malaysia. 

 
 
 
 
PARTICIPANTS 
 Participants were recruited from general student population around Kuantan 
with following criteria: 
o Inclusion Criteria 
 Subjects of age group 18 to 30 years. 
 Both males and females. 
 No recent history of lower limb injuries. 
 Subjects with bilateral flexible flat feet as per the definition. 
 Subjects with positive navicular drop test (> 10mm) and positive Jack’s test. 
          
o Exclusion criteria 
 Rigid flat foot  
 Subject who are involved in a specific sport at least 2 h /day and 3 times a week 
regularly. 
 History of arthritic symptoms of lower limb joints. 
 History of any ligament or tendon injuries around ankle, knee, or hip joint. 
 History of any limb surgery or back surgery. 
 Chronic back pain. 
 Any history of neurological deficit or diabetic neuropathy. 
 
 
 
 
 
 
 
 
 
 
 

INTERVENTIONS 
 
Experimental Group 
 
Six-week exercise protocol with progression developed following systematically reviewing 
bod of evidences and tested for feasibility and acceptability in pilot trial. 
 
 
Exercises 
Repetitions 
and 
phase 
wise 
progression 
Rest 
period 
between 
exercise sets 
Warm 
up 
(Back 
arching 
and 
knee 
rolling) 
3 times each exercise 
5 sec rest between exercises 
Abdominal hollowing 
Repeat until the subject learns to 
contract core muscles. 
5 sec rest between each trial 
Curl ups with hands 
behind head  
Phase 1:10 rept × 3 times 
120 sec rest between the sets 
 
 
Phase 2: 15 rept × 3 times 
Phase 3:  20 rept × 3 times 
Bridges with leg lifts 
Phase 1: 15 sec hold × 3 times 
120 sec rest between the sets 
Phase 2: 20 sec hold × 3 times 
Phase 3: 25 sec hold × 3 times 
Side bridges  
Phase 1: 15 sec hold × 3 times 
120 sec rest between the sets 
Phase 2: 20 sec hold × 3 times 
Phase 3: 25 sec hold × 3 times 
Planks on feet 
Phase 1: 15 sec hold × 3 times 
120 sec rest between the sets 
Phase 2: 20 sec hold × 3 times 
Phase 3: 25 sec hold × 3 times 
Quadripedal 
stance 
with contralateral arm 
and leg raise. 
Phase 1: 15 sec hold × 3 times 
120 sec rest between the sets 
Phase 2: 20 sec hold × 3 times 
Phase 3: 25 sec hold × 3 times 
Cool Down  
Self-stretching of hamstrings and calf in long sitting position 3 
times with 10 sec hold. 

Control Group 
Conventional foot exercises for control group (3 times weekly for 6 weeks) adapted from 
previous studies. 
A. Warm up: 
Active ROM exercise (Knee and hip flexion) 10 repetitions × 2 sets) 
 
 
B. Training: 
 Active dorsiflexion exercises in long sitting (10 sec hold × 15 repetitions ×2 
sets) 
 Active plantarflexion exercises in long sitting (10 sec hold × 15 repetitions ×2 
sets) 
 Active inversion exercises in long sitting (10 sec hold × 15 repetitions ×2 sets) 
 Active eversion exercises in long sitting (10 sec hold × 15 repetitions ×2 sets) 
 
C. Cool down: 
 Calf stretches in long sitting for 10 seconds hold × 3 sets. 
 
 
OUTCOME MEASUREMENTS 
 
 Rearfoot Angle (Right & Left) 
Rear foot angle was measured by testers using Goniometer in standing position. 
 Staheli Plantar Arch Index (SPAI ) (Right & Left) 
SPAI was measure using footprint method and calculation of arch index 
 Q Angle (Right & Left) 
Q angle was measure using Goniometer. 
 
ASSESSMENT TIMELINE 
 
 Baseline 
 Post Intervention after 6 weeks 

SAMPLE SIZE 
 Initially Pilot trial started with a sample size of 20 for assessing feasibility 
 After completion of protocol, a sample size of 62, determined using G power was 
recommended. 
 
 
SAMPLING 
 Participants were recruited using convenience sampling and randomly assigned to 
either the experimental (core stability) group or control (conventional exercises) group. 
Randomization was performed using a blinded lottery method, in which eligible 
participants were coded, and the codes were placed in a container. An independent 
assessor randomly allocated participants to each group using these codes. 
 
BLINDING 
 Assessors were blinded to group allocation during the randomization process. 
Participants and intervention-givers were not blinded due to the nature of the exercise 
intervention. 
 
STATISTICAL ANALYSIS 
 Changes scores (Post mean – Pre mean) were calculated and multivariate analysis was 
conducted with BMI as a covariate. 
 
ETHICAL CONSIDERATIONS 
 
Ethics approval was obtained from IREC, Research management centre, International 
Islamic University of Malaysia with protocol Id -IREC 2024-257 
 
Written informed consent was obtained from all participants prior to enrolment. 
 
 
 

INFORMED CONSENT FORM 
 
INTERNATIONAL ISLAMIC UNIVERSITY MALAYSIA 
KULLIYAH OF ALLIED HEALTH SCIENCES 
 
Informed Consent form for: 
This Informed Consent form is for adults aged 18 to 30 years of both genders who we are 
inviting to participate in research on Bilateral flexible flat feet. The title of our research 
project is “Identification of exercise components of core stability and their effectiveness 
on foot posture, foot function and lower limb alignment in adults with flexible flat feet”. 
 
Name of Principal Investigator: ________________________ 
 
 
Name of Organization:         ________________________ 
 
 
Name of Sponsor: ________________________ 
 
 
This Informed Consent Form has two parts: 
 Information Sheet (to share information about the research with you). 
 
 Certificate of Consent (for signatures if you agree to take part). 
 
          You will be given a copy of the full Informed Consent Form. 
 
 

PART I: Information Sheet 
 
Introduction 
I am Mr. ___________ a PhD student for the International Islamic university of Malaysia. I 
am doing research to check the efficacy of core stability exercises on the flat feet.  I am going 
to give you information and invite you to be part of this research. You do not have to decide 
today whether you will participate in the research. Before you decide, you can talk to anyone 
you feel comfortable with, about the research. 
This consent form may contain words that you do not understand. Please ask me to stop as we 
go through the information, and I will take time to explain. If you have questions later, you 
can ask them of me or of another researcher. 
 
Purpose of Research 
Flexible flat feet are very common and affect other joints of the limbs and low back if not 
treated on time. We want to find ways to stop this from happening. We want to use special 
exercises called core stability exercises for the treatment of flexible flat feet. We want to learn 
whether these exercises will help the people with flat feet in any means.  
 
Type of research intervention 
This research will involve exercises for back (core stability exercises) and exercises for foot 
in a single session as well as four follow-up visits to the clinic. 
 
Participant selection 
We are inviting all adults aged between 18 to 30 years with flexible flat feet who attend clinic 
of Department of physical Rehabilitation Sciences, IIUM Kuantan to participate in the 
research on the use of core stability exercises on flat feet. 
 
Voluntary participation 
Your participation in this research is entirely voluntary. It is your choice whether to 
participate or not. If you choose not to participate all the services, you receive at this Centre 
will continue and nothing will change. You may change your mind later and stop 
participating even if you agreed earlier. 
 
Information on trial 
The exercises used in this research are called core stability exercises and foot muscle 
exercises. These exercises have been tested before in various other conditions. We want to 

test their effect on bilateral flexible flat feet. Some participants will be given core stability 
exercises, and some will be given foot exercises. There is no risk involved both the sets of 
exercises. 
 
Procedure and protocol 
 
A. Description of process 
 
We are asking you to help us learn more about flexible flat feet. If you accept, you 
will be asked to visit the clinic at least 3 to 4 times weekly for 45 minutes treatment 
sessions. In every session you will be performing exercise sessions. Before the 
sessions start a pretesting of your foot arch, lower limb alignment and foot function 
will be assessed, and same tests will be repeated after the completion of the treatment 
sessions. 
 
 Duration 
The research takes place over 4 weeks in total. During that time, it will be necessary 
for you to come to the clinic 3 times weekly, for 1 hour each day.In total, you will be 
asked to come 12 times to the clinic in 4. At the end of 4 weeks, the research will be 
finished. 
 Side effects 
As stated earlier there are no side effects for these exercises. However, you might feel 
bit tired after doing exercise session and that will recover after taking rest. 
 
 Risks 
There are no risks involved with this intervention. 
 
 Benefits 
If you participate in this research, you will have the following benefits:  
The treatment for your flexible flat feet will be free of charge. There may not be any 
benefit for you, but your participation is likely to help us find the answer to the 
research question. There may not be any benefit to the society at this stage of the 
research, but future generations are likely to benefit. 
 
 Reimbursements 
You will not be provided any incentive to take part in the research. 
 
 Confidentiality 
The information that we collect from this research project will be kept confidential. 
Information about you that will be collect during the research will be put away and 
no-one, but the researchers will be able to see it. Any information about you will have 
a number on it instead of your name. Only the researchers will know what your 
number is, and we will lock that information up. 

 Sharing the Results 
The knowledge that we get from doing this research will be shared with you if you 
wish so.  
  
 Right to Refuse or Withdraw 
You do not have to take part in this research if you do not wish to do so. You may also 
stop participating in the research at any time you choose. It is your choice, and all 
your rights will still be respected. 
 
 Who to Contact 
If you have any questions, you may ask them now or later, even after the study has 
started. If you wish to ask questions later, you may contact any of the following: 
Name: Shahid Mohd Dar 
Address: Kulliyah Allied Health Sciences, IIUM Kuantan. 
Telephone number: 0169807816 
E-mail: shahiddar@iium.edu.my 
 
 
This proposal has been reviewed and approved by IREC, which is a committee whose 
task it is to make sure that research participants are protected from harm. If you wish 
to find about more about the IREC, contact: 
Name: 
Address: IIUM Research Ethics Committee (IREC), Research Management Centre 
(Kuantan) Level 1, Admin Building (OCD). International Islamic University Malaysia 
Bandar Indera Markota, 25200 Kuantan, Pahang 
Telephone number: 09-5704733/4227 
 
PART II: Certificate of Consent 
I have read the foregoing information, or it has been read to me. I have had the 
opportunity to ask questions about it and any questions that I have asked have been 
answered to my satisfaction. I consent voluntarily to participate as a participant in this 
research. 
Print Name of Participant__________________ 
 
Signature of Participant ___________________ 
 
Date ___________________________ 
             Day/month/year 

 
IF ILLITERATE: 
I have witnessed the accurate reading of the consent form to the potential participant, 
and the individual has had the opportunity to ask questions. I confirm that the 
individual has given consent freely. 
 
Print name of witness____________________ AND    Thumb print of participant 
 
Signature of witness ______________________ 
 
Date ________________________ 
           Day/month/year 
 
Statement by the researcher/person taking consent. 
I have accurately read out the information sheet to the potential participant, and to the 
best of my ability made sure that the participant understands that the following will be 
done: 
1. 
2. 
3. 
I confirm that the participant was given an opportunity to ask questions about the 
study, and all the questions asked by the participant have been answered correctly and 
to the best of my ability. I confirm that the individual has not been coerced into giving 
consent, and the consent has been given freely and voluntarily. 
A copy of this ICF has been provided to the participant. 
Print Name of Researcher/person taking the consent________________________ 
 
Signature of Researcher /person taking the consent__________________________ 
 
Date ___________________________ 
Day/month/year