Enhancing Balance, Agility, and Strength in Amateur Badminton Players Using a Novel Badminton Specific Square-Stepping Exercise (Bs-SSE)
Phase: NA
Conditions: Physical Performance
Sponsor: INTI International University

Retrospective Registration Study Protocol 
Page 1 
Study Protocol for Retrospective Registration 
Enhancing balance, agility and strength in amateur badminton players using a novel 
badminton-specific square-stepping exercise (bs-SSE) 
Important note. This protocol reformats a completed quasi-experimental study for retrospective 
registration. Fields not reported in the manuscript are flagged for investigator confirmation. 
Administrative information 
Protocol version 
Version 1.0 
Protocol date 
March 31 2026 
Study status 
Completed study; final analysis already conducted 
Registration status 
Prepared for retrospective registration 
Design 
Two-arm, parallel-group, quasi-experimental intervention study 
Ethics approval 
University Research Ethics Committee, INTI-IU/FHLS-
RC/BPHTI/7NY12022/020 
Funding 
No funds, grants or other support declared 
Data availability 
Available upon reasonable request to the corresponding author 
Protocol source 
Reformatted from the revised manuscript supplied by the investigators 
Registration-oriented summary 
Scientific title 
Enhancing balance, agility and strength in amateur badminton players using a 
novel badminton-specific square-stepping exercise (bs-SSE) 
Public title 
Badminton-specific square-stepping exercise to improve balance, agility and 
ankle strength in amateur badminton players 
Health condition / focus 
Physical performance in amateur badminton players (dynamic balance, agility, 
and ankle strength) 
Setting 
Amateur badminton players in Malaysia 
Participants 
Adults aged 18–40 years with at least 5 years of badminton experience and 
current participation of 2–4 hours per week 
Intervention 
Eight-week badminton-specific square-stepping exercise programme 
delivered on a 2.5 m × 1.0 m mat divided into 40 squares 
Comparator 
Usual activity with no additional structured bs-SSE programme 
Assessment schedule 
Baseline, week 4 and week 8 
Outcome domains 
Dynamic balance, agility, and ankle dorsiflexor/plantar flexor strength 
Sample size 
66 participants recruited; 60 participants (30 per group) analysed after attrition 
and one additional control exclusion 

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Protocol summary 
Background: Badminton involves repeated accelerations, lunges, landings and directional changes, placing 
high demands on balance, agility and ankle function. Amateur players may not routinely receive structured 
sport-specific conditioning. 
Objective: To evaluate whether an eight-week bs-SSE programme improves dynamic balance, agility and ankle 
strength in amateur badminton players. 
Design: Retrospectively documented quasi-experimental study with assessments at baseline, week 4 and 
week 8. 
Methods: Eligible participants were allocated to an intervention group receiving bs-SSE or a control group 
continuing usual activity. Outcomes were measured with the Y-Balance Test, Agility T-test and handheld 
dynamometry. 
Completed-study status: The study has been completed and analysed. This document restates the original 
study methods in protocol format for retrospective registration. 
Background and rationale 
Badminton is a demanding racquet sport characterised by rapid changes of direction, repeated lunges, 
jumping, landing and complex footwork. These actions require efficient postural control, neuromuscular 
coordination and lower-limb force production. 
Dynamic balance is central to effective rally movement because players must control their centre of mass 
while accelerating, decelerating and recovering across the court. Agility is equally important because 
successful play depends on fast, accurate multidirectional movement. The ankle complex contributes 
substantially to propulsion, stability and controlled landing, while also representing a common site of injury in 
amateur badminton players. 
The badminton-specific square-stepping exercise (bs-SSE) programme was designed to combine progressive 
multidirectional stepping patterns with badminton footwork demands in a structured format suitable for 
amateur players. 
Objectives and study hypothesis 
The objective was to determine whether an eight-week bs-SSE programme could improve physical 
performance domains relevant to badminton in amateur players. 
The study evaluated changes in dynamic balance, agility and ankle strength over time and compared those 
changes between the intervention group and the control group. 
The hypothesis was that participants receiving bs-SSE would improve more than those continuing usual 
activity. 
Methods 
Study design 
This was a two-arm, parallel-group, quasi-experimental intervention study with repeated assessments at 
baseline, week 4 and week 8. Because the source manuscript describes group assignment without confirming 
randomisation, the study is documented here as non-randomised. 
Participants and eligibility criteria 
• 
Inclusion criteria: age 18–40 years; at least 5 years of singles or doubles badminton experience; currently 
playing badminton 2–4 hours per week; ability to understand instructions in English; and clearance on the 
Exercise Preparticipation Health Screening Questionnaire for Exercise Professionals. 
• 
Exclusion criteria: upper- or lower-limb injury within the preceding 6 months; musculoskeletal, 
neurological, visual, vestibular, cardiorespiratory or cognitive disorders; regular participation in sports 

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other than badminton; current use of analgesics, muscle relaxants or neuroleptic medication; pregnancy; 
or a positive response on Step 2 and any item in Step 3 of the screening questionnaire. 
Sample size and analysed sample 
The manuscript states that sample size estimation was performed in G*Power version 3.1 for a repeated-
measures analysis involving two groups and three measurement points. A total of 66 participants were 
recruited. The final analysed sample comprised 60 participants, with 30 in the control group and 30 in the 
experimental group, after attrition and exclusion of one additional control participant to maintain equal final 
group sizes. 
Recruitment, consent and group allocation 
Participants who met the eligibility criteria provided written informed consent before participation. The 
manuscript indicates allocation to intervention or control groups, but the exact allocation method should be 
confirmed before registry submission. 
Intervention: badminton-specific square-stepping exercise (bs-SSE) 
The bs-SSE programme was delivered over 8 weeks on a 2.5 m × 1.0 m mat divided into 40 equal squares. 
The programme used progressive forward, backward, lateral and diagonal stepping patterns designed to 
simulate badminton footwork demands. 
Each session comprised a light-intensity warm-up (57 to <64% HRmax), a 30-minute moderate-intensity 
exercise phase (64 to <76% HRmax), and a very light-intensity cool-down (<57% HRmax). 
The training content was adapted from the original square-stepping exercise approach. The manuscript reports 
excellent expert content validity for the bs-SSE protocol (I-CVI = 1.00; S-CVI/Ave = 1.00). Participants in the 
intervention group completed the bs-SSE programme five days per week, with each session lasting 30 minutes, 
for a total of eight weeks. 
Comparator 
The control group continued their usual daily and physical routines and did not receive the additional bs-SSE 
programme. 
Outcome measures 
Outcome domain 
Instrument / metric 
Time points 
Dynamic balance 
Y-Balance Test with anterior, posteromedial 
and posterolateral reaches 
Baseline, week 4, week 8 
Agility 
Agility T-test; lower values indicate better 
performance 
Baseline, week 4, week 8 
Ankle strength 
Handheld dynamometer measurement of 
bilateral dorsiflexor and plantar flexor strength 
(Newtons) 
Baseline, week 4, week 8 
Assessment schedule 
Measure 
Baseline 
Week 4 
Week 8 
Eligibility screening and informed consent 
Yes 
No 
No 
Dynamic balance assessment 
Yes 
Yes 
Yes 
Agility assessment 
Yes 
Yes 
Yes 
Ankle strength assessment 
Yes 
Yes 
Yes 
Data handling and statistical analysis 
Statistical analysis was conducted using IBM SPSS Statistics version 25.0. 

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Descriptive statistics summarised demographic and baseline characteristics, and normality was assessed 
before parametric testing. 
Within-group changes across time were analysed using repeated-measures analysis of variance. Between-
group differences at each time point were examined using independent-samples t-tests. Bonferroni 
adjustment was applied where appropriate. Statistical significance was defined as a two-tailed p value of less 
than 0.05. 
Ethics, confidentiality and dissemination 
The study received ethical approval under reference INTI-IU/FHLS-RC/BPHTI/7NY12022/020 and was reported 
as compliant with the Declaration of Helsinki (2013). 
Participants provided written informed consent before enrolment. The manuscript does not describe 
confidentiality procedures in detail; these can be added if required by the intended registry. 
The investigators stated that data are available upon reasonable request to the corresponding author. Findings 
from the completed study were prepared for manuscript publication and academic dissemination. 
Completed-study statement for retrospective registration 
This document was prepared after completion of recruitment, follow-up and statistical analysis. It is therefore 
a retrospective protocol reconstruction rather than a prospectively registered protocol. 
The methods, intervention description, eligibility criteria, outcomes and analysis plan were derived from the 
revised manuscript and should be checked against original study records before registry submission. 
 
End of protocol