The Effectiveness of an Exercise Program on Scapulohumeral Rhythm, Range of Motion, and Stability in Young Female Handball Players

The Effectiveness of an Exercise Program on Scapulohumeral Rhythm, Range of Motion, and Shoulder Girdle Stability in Young Female Handball Players

This record describes a planned randomized parallel-group trial of a modified Watson-based shoulder exercise program in female handball players. An internal pilot phase was conducted first to evaluate feasibility and obtain preliminary estimates to inform the definitive trial.

Study Overview

• Status: Active, not recruiting
• Conditions: Scapular Dyskinesis; Handball Players; Female Athlete
• Intervention / Treatment: Other: Modified Watson-based scapular exercise program; Other: Active Comparator: Standard upper-limb exercise program

Detailed Description

The aim of this study is to investigate the effects of a structured shoulder girdle exercise programme on stability, range of motion (ROM) and motor control in female handball players. The study will be conducted over a period of 8 weeks and will involve 60 participants aged 17-30 years recruited from professional handball clubs. Participants will be randomly assigned to either the experimental group, which will follow a modified version of the Watson programme, or the control group, which will continue with their standard training programme. Aims: - To compare the effects of the upper scapular rotation-oriented exercise intervention with a standardised upper extremity exercise programme. - Scapulohumeral rhythm assessment: To assess scapulohumeral rhythm at different angles of shoulder flexion (30°, 60°, 90° and 120°) in young female handball players, with a focus on identifying potential asymmetries between the dominant and non-dominant limbs. - Analysis of scapular kinematics: To measure scapular upward rotation, anterior/posterior tilt and medial/lateral translation at different degrees of shoulder flexion to identify movement patterns associated with scapular dyskinesis. - Functional stability analysis: To assess upper extremity functional stability using the Y-Balance Upper Quarter Test (YBT-UQ) and the Closed Kinetic Chain Upper Extremity Stability Test pre- and post-exercise to identify potential correlations between stability improvements and changes in scapular rhythm and muscle activation. - Isometric strength measurement: To evaluate isometric strength in shoulder abduction, internal rotation and external rotation using the Lafayette HHD handheld dynamometer to assess the impact of the intervention on shoulder muscle performance.

An internal pilot phase of this registered study was conducted between March and September 2025 to assess feasibility, retention, adherence, safety, and preliminary variability of outcome measures before progression to the full trial. Seventeen participants were enrolled and 14 completed post-intervention assessment. Findings from this pilot phase are being reported separately in a manuscript focused on feasibility and preliminary effect estimation. The definitive randomized trial remains planned contingent on feasibility findings and available resources.

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Poland
  • Pomeranian Voivodeship
    • Gdansk, Pomeranian Voivodeship, Poland, 80-211
      • Department of Immunobiology and Environment Microbiology, Medical University of Gdańsk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy individuals with no reported health problems
• No history of shoulder or elbow surgery within the past 2 years
• Received information about the study
• Written consent from the participant to participate in the study, including video recording and photography

Exclusion criteria:

• Injury or trauma to the upper extremity within the past 3 months
• Illness that prevents participation in the study or tests
• Heavy physical activity of the shoulder girdle within 2 hours prior to the study
• Orthopedic surgery or physiotherapy treatment of the shoulder girdle

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental: Modified Watson-based scapular exercise program; Participants undergo baseline and post-intervention assessment including scapulohumeral rhythm, range of motion, isometric shoulder strength, Upper Quarter Y-Balance Test, and Closed Kinetic Chain Upper Extremity Stability Test. The intervention lasts 8 weeks and is divided into four consecutive 2-week phases targeting the dominant upper extremity. Participants receive scapular positioning correction and scapular-specific cueing aimed at improving upward rotation and neuromuscular control during exercise performance. Two elastic resistance bands are used: one to facilitate scapular upward rotation control and one to provide external resistance during the exercises. Participants are instructed to perform the home exercise program daily for approximately 10 minutes.	Other: Modified Watson-based scapular exercise program; An 8-week dominant-limb exercise program based on the Watson rehabilitation approach, incorporating scapular positioning correction, scapular-specific cueing, and progressive exercises performed with two elastic resistance bands.
Active Comparator: Active Comparator: Standard upper-limb exercise program; Participants undergo baseline and post-intervention assessment including scapulohumeral rhythm, range of motion, isometric shoulder strength, Upper Quarter Y-Balance Test, and Closed Kinetic Chain Upper Extremity Stability Test. The control intervention lasts 8 weeks and is divided into four consecutive 2-week phases targeting the dominant upper extremity. Participants perform a standardized upper-limb exercise program without scapular positioning correction, without scapular-specific cueing, and without specific upward-rotation facilitation. One elastic resistance band is used to provide external resistance during the exercises. Participants are instructed to perform the home exercise program daily for approximately 10 minutes.	Other: Active Comparator: Standard upper-limb exercise program; An 8-week dominant-limb standardized upper-limb exercise program performed with one elastic resistance band and without scapular positioning correction or scapular-specific cueing.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Scapulohumeral rhythm	Scapular upward rotation is assessed with the Digital Inclinometer (BASELINE 12-1057) in a seated position to minimize compensatory movements of the trunk and lower extremities. The first measurement is taken at baseline (0° of shoulder flexion), followed by additional measurements at 30°, 60°, 90°, and 120° of shoulder flexion. Each position is held for 10-15 seconds to ensure stable measurement conditions. Measurements are repeated three times and the average is used for analysis. The assessment will be performed on both the dominant and non-dominant upper limb to evaluate movement symmetry. Data will be recorded manually by a research assistant to reduce the risk of reading errors and to ensure measurement accuracy. Statistical analysis will be performed to determine the scapulohumeral rhythm across different ranges of motion and to identify potential movement asymmetries.	through study completion, an average of 2 years
ISOMETRIC STRENGTH TEST - Internal and External Rotation	Isometric strength assessment of the shoulder girdle muscles will be conducted using the Lafayette Hand-Held Dynamometer (HHD). For the rotator muscles, measurements will be performed in the prone position with the shoulder abducted to 90° and the elbow flexed to 90°, with the forearm hanging freely over the edge of the examination table. This setup will be used for both internal and external rotation strength assessments. Results are expressed in Newtons (N) or normalized to body weight as Newtons per kilogram (N/kg).	through study completion, an average of 2 years
Y-Balance Upper Quarter Test (YBT-UQ)	The Y-Balance Upper Quarter Test (YBT-UQ) is used to assess upper extremity stability and reach performance. The test requires the participant to maintain a single-arm support position while the opposite arm performs reaching movements in three directions: anterior (forward), inferolateral (diagonally opposite the supporting hand), and superolateral (diagonally toward the supporting hand). Each reach is measured in centimeters, and the final score for each direction is calculated as the average of three trials. The test will be performed on both upper limbs and arm length will be included in the analysis to ensure standardized results. Results will be reported in centimeters, "cm", and Upper Limb Length % (standardized by upper limb length).	through study completion, an average of 2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Closed Kinetic Chain Upper Extremity Stability Test	Two strips of tape will be placed on the floor 90 cm apart. Participants will be instructed to assume a push-up position and perform as many hand touches as possible on each strip within 15 seconds. The examiner will count the number of touches. Three trials will be conducted, and the final score will be calculated as the average number of touches across all three trials. A 45-second rest period will be provided between each trial. The CKCUEST score and CKCUEST power will be calculated using the following formulas: Score = Average number of touches on CKCUEST / height (m); Power = 68% of body weight (kg) × Average number of touches on CKCUEST	through study completion, an average of 2 years
RANGE OF MOTION (Shoulder Internal and External Rotation)	Range of motion is measured for internal and external rotation of the shoulder. The participant is positioned in the prone position with the shoulder abducted to 90 degrees and the elbow flexed to 90 degrees, allowing the forearm to hang freely over the edge of the examination table. The starting position (0 degrees) is defined as the forearm being vertically aligned. Results are presented in degre	through study completion, an average of 2 years

Collaborators and Investigators

• Sponsor: Medical University of Gdansk
• Collaborators: Gdansk Medical Academy of Applied Sciences
• Investigators: Principal Investigator: Bartosz Wilczyński, Medical University of Gdansk

Study record dates

Study Major Dates

• Study Start (Actual): March 8, 2025
• Primary Completion (Actual): September 10, 2025
• Study Completion (Estimated): February 10, 2028

Study Registration Dates

• First Submitted: March 8, 2025
• First Submitted That Met QC Criteria: March 8, 2025
• First Posted (Actual): March 13, 2025

Study Record Updates

• Last Update Posted (Actual): May 7, 2026
• Last Update Submitted That Met QC Criteria: May 1, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Scapular dyskinesis; Handball; Sports Performance Assessment; Muscle Strength assessment; Scapular
• Additional Relevant MeSH Terms: Neurologic Manifestations; Central Nervous System Diseases; Nervous System Diseases; Movement Disorders; Dyskinesias
• Other Study ID Numbers: KB/42/2025

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Data on OSF (osf.io/n9ket/)
• IPD Sharing Time Frame: Beginning upon publication and available indefinitely.
• IPD Sharing Access Criteria: Available via OSF repository without restriction.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No