2D Key-Event Joint Angles Across Phases of the Badminton Overhead Smash in Elite Colombian Players (BAD-2D-SMASH)

Preliminary Dominant-side 2D Key-event Joint-angle Descriptors Across Five Phases of the Badminton Overhead Smash in Elite Colombian Players: a Cross-sectional Exploratory Case Series

Phase-based descriptions of the badminton overhead smash can support coach-relevant feedback when laboratory motion capture is impractical. This cross-sectional exploratory case series characterises dominant-side, two-dimensional key-event joint-angle configurations (knee, hip, shoulder, elbow) across five phases (preparation, start, acceleration, impact, termination) in elite Colombian players from the Antioquia Badminton League. Athletes performed three maximal-effort smashes; one trial per athlete was selected for analysis using pre-defined visibility criteria, and one key-event frame per phase was digitised in Kinovea. Outcomes are descriptive phase-specific angle values and between-athlete dispersion metrics. The study is retrospectively registered for transparency.

Study Overview

• Status: Completed
• Conditions: Sports Performance; Biomechanics; Video Information

Detailed Description

Badminton overhead smash performance depends on coordinated whole-body contributions and is often judged qualitatively in applied settings. This study provides a field-based, minimal-equipment description of dominant-side planar joint-angle configurations across five technical phases of the overhead smash using a single lateral high-speed camera. Five elite athletes (men n=4; woman n=1) from the Antioquia Badminton League were recorded at 240 frames·s-¹ during maximal-effort smashes. Phases were defined as preparation (F1), start (F2), acceleration (F3), impact (F4), and termination (F5), with one key-event frame selected per phase. Knee, hip, shoulder, and elbow internal angles were extracted via three-point definitions in Kinovea. Data are reported descriptively (male subgroup as mean±SD and CV%; female case descriptively). The intention is to offer coach-interpretable phase references and to identify phases with higher inter-individual dispersion.

• Study Type: Observational
• Enrollment (Actual): 4

Contacts and Locations

Study Locations

• Colombia
  • Antioquia
    • Medellín, Antioquia, Colombia, 054080
      • Tecnológico de Antioquia

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

High-performance adult badminton players from the Antioquia Badminton League (Colombia) with extensive competitive experience, assessed in a single session to describe 2D phase-based overhead smash joint-angle configurations.

Description

Inclusion Criteria:

• 5 years of organised badminton experience
• Current Antioquia Badminton League affiliation
• Competitive participation in ≥5 federated tournaments
• Previous selection to a representative team at least at national level
• Able to execute maximal-effort overhead smashes on the testing day

Exclusion Criteria:

• Pain or musculoskeletal complaints affecting upper limb, trunk, or lower limb on the testing day
• Any condition preventing maximal-effort overhead smashes

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Elite badminton players (Antioquia); Elite badminton athletes from the Antioquia Badminton League (Colombia), aged ≥18 years, with >5 years of organised experience, competitive participation in ≥5 federated tournaments, and previous selection to at least national representative level. Participants completed a single testing session involving three maximal-effort overhead smashes recorded with a single lateral high-speed camera for 2D phase-based joint-angle extraction; no interventions were assigned.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
2D sagittal-plane joint angles at key events during the smash (knee, hip, shoulder, elbow)	Internal joint angles (degrees) for the knee, hip, shoulder, and elbow computed using three-point (planar) definitions at five pre-defined key-event frames (F1-F5) spanning the smash phases. Angles will be extracted from lateral high-speed video after landmark digitisation in Kinovea using pre-specified anatomical landmarks and segment definitions. Data will be reported as mean (SD) for each joint and key-event frame; larger values indicate more extended joint configurations.	Baseline (Visit 1; up to 30 minutes)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Between-participant variability (SD and CV%) of 2D sagittal-plane joint angles by key-event frame and joint	Between-participant dispersion of the 2D sagittal-plane joint angles (knee, hip, shoulder, elbow) at each pre-defined key-event frame (F1-F5). Variability will be summarized as (i) standard deviation (SD, degrees) and (ii) coefficient of variation (CV%, 100×SD/mean) across participants for each joint × key-event frame. Variability will be reported for the overall sample and, if applicable, stratified by sex as a pre-specified exploratory analysis.	Baseline (Visit 1; up to 30 minutes)

Collaborators and Investigators

• Sponsor: Federal University of Vicosa

Study record dates

Study Major Dates

• Study Start (Actual): February 12, 2025
• Primary Completion (Actual): February 13, 2025
• Study Completion (Actual): February 13, 2025

Study Registration Dates

• First Submitted: February 23, 2026
• First Submitted That Met QC Criteria: February 26, 2026
• First Posted (Actual): March 2, 2026

Study Record Updates

• Last Update Posted (Actual): March 2, 2026
• Last Update Submitted That Met QC Criteria: February 26, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: joint angles; badminton; overhead smash; 2D video analysis; technique variability
• Other Study ID Numbers: Badminton-TdeA

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared publicly because the sample is very small and drawn from an identifiable elite sports environment, meaning that de-identified records could still be re-identified when combined with contextual information. In addition, the source materials include video-derived measures, and participant consent was obtained for analysis and publication of aggregated results rather than unrestricted public release of participant-level data. Summary statistics and methodological details are reported in the publication; additional details may be considered on a case-by-case basis under a data-use agreement and ethics constraints.

Drug and device information, study documents

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