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

N/AActive Not RecruitingNCT06875596

Medical University of Gdansk60 enrolled

Overview

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.

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

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

Conditions

Scapular Dyskinesis Handball Players Female Athlete

Interventions

Modified Watson-based scapular exercise programOTHER

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: Standard upper-limb exercise programOTHER

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.

Eligibility

Sex: FEMALEMin age: 16 YearsMax age: 45 YearsHealthy volunteers:

Medical Language ↔ Plain English

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

Locations (1)

Department of Immunobiology and Environment Microbiology, Medical University of Gdańsk

Gdansk, Pomeranian Voivodeship, Poland

Outcomes

Primary Outcomes

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.

Time frame: 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).

Time frame: 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).

Data from ClinicalTrials.gov

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