Kinematics and Muscle Activity During the Tennis Serve and Musculoskeletal Characteristics in Tennis Players With Subacromial Pain Syndrome or History of Shoulder Pain

Tennis players often suffer from shoulder pain due to the repetitive high-loaded overhead movements during serving, and subacromial pain syndrome is one of the main types of shoulder pain. Previous shoulder injury has been identified as one of the risk factors for shoulder overuse injuries in overhead sports. No research has explored differences in trunk kinematics and shoulder muscle activities among tennis players with and without subacromial pain syndrome or a history of shoulder pain. Furthermore, limited studies have examined shoulder kinematics during tennis serve and musculoskeletal characteristics in tennis players with subacromial pain syndrome or a history of shoulder pain. Therefore, this study aims to investigate shoulder and trunk kinematics and shoulder muscle activity during the tennis serve and musculoskeletal characteristics in tennis players with subacromial pain syndrome or a history of shoulder pain. This study will recruit sixty tennis players with subacromial pain syndrome, a history of shoulder pain, and healthy players. The electromagnetic tracking system will be applied to collect shoulder and trunk kinematics during the tennis serve, and surface electromyography will be simultaneously used for recording shoulder muscle activities. Moreover, we will collect shoulder and trunk rotational joint range of motion, isometric strength and rate of force development of shoulder internal and external rotation, scapulothoracic and glenohumeral joint control capability, upper quarter Y-balance test performance, and posterior shoulder endurance. This study will compare the difference of these measures in tennis players with subacromial pain syndrome or a history of shoulder pain to healthy players.

Study Overview

• Status: Recruiting
• Conditions: Shoulder Pain

• Study Type: Observational
• Enrollment (Estimated): 60

Contacts and Locations

Study Locations

• Taiwan
  • Taipei, Taiwan
    • Recruiting
    • No. 155, Sec. 2, Linong St. Beitou Dist., Taipei City 112304, Taiwan
    • Contact: I, Chen Cheng; Phone Number: +886 966-719-573; Email: ted724.be13@nycu.edu.tw

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Tennis players in Taiwan

Description

Inclusion Criteria:

• Amateur tennis players
• National Tennis Rating Program (NTRP) should level ≥ 3.5
• Training experience: ≥ 3 years, current or former school team players
• Training volume: ≥ 4 hours/week

Exclusion Criteria:

• Any current musculoskeletal injuries preventing maximum skill execution at the time of testing
• Previously had any form of surgery or trauma
• Patient-reported pain that will inhibit participation in this study

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort
subacromial pain syndrome; (1) Shoulder pain that had lasted for at least 3 months and recurred during flat serves in matches or practice; and (2) positive results in at least 3 of the 5 subacromial impingement tests, including the empty can test, Neer impingement test, Hawkins-Kennedy impingement test, resisted external rotation test, and painful arc during shoulder elevation.
history of shoulder pain; Within 6 months prior to the begin of the experiment, the participant was absent from or had to adjust one practice or competition due to pain in the dominant shoulder joint.
healthy; The healthy group had no neck pain, shoulder pain, or disability on their dominant side within the six months prior to the start of the experiment

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Degree of the glenohumeral and scapulothoracic joint during serving	The kinematics is assessed using an electromagnetic motion tracking system (VIPERTM, Polhemus, USA) and IMU (Inertial Measurement Unit) systems (Noraxon USA, Scottsdale, AZ, USA) to collect the glenohumeral elevation, horizontal abduction/adduction, internal/external rotation, scapulothoracic retraction/protraction, upward/downward rotation, anterior/posterior tilt, and trunk rotation, sidebending, flexion/extension during tennis serve. During the test, participants performed 5 flat serves, with 60 seconds of rest between each trial. Data were analyzed at the end of the arm cocking (maximal shoulder horizontal abduction), at ball-contact (peak of acceleration or perturbation in IMU), and at the end of the arm deceleration (maximal shoulder horizontal adduction). Data will report as mean values for each trial. (unit of measure: degree, °)	Day 1
Amplitude of the activation of glenohumeral and periscapular muscles	The muscle activation amplitude of the upper trapezius, lower trapezius, serratus anterior, latissimus dorsi, pectoralis major, biceps brachii, and triceps brachii would be recorded during tennis serve. During the test, participants performed 5 serves, with 60 seconds of rest between each trial. Data were collected in the arm cocking phase (from shoulder elevation over 5 standard deviation form resting to the shoulder maximal horizontal abduction) and the acceleration phase (from maximal shoulder horizontal abduction to the ball-contact), and the deceleration phase (from ball-contact to maximal horizontal adduction). The data will be reported as mean values for each trial. (unit of measure: percentage, %)	Day 1
Shoulder active range of motion	Shoulder external rotation and internal rotation range of motion in shoulder flexion 90 degrees in supine. An inclinometer will used for the test. The test will perform 3 times. Data will report as mean values for each trial. (unit of measure: degree, °)	Day 2
Shoulder passive range of motion	Shoulder external rotation and internal rotation range of motion in shoulder flexion 90 degrees in supine. An inclinometer will used for the test. The test will perform 3 times. Data will report as mean values for each trial. (unit of measure: degree, °)	Day 2
Trunk rotational range of motion	Trunk rotational range of motion would be tested in lumbar locked position. An inclinometer will used for the test, and participants active rotate their trunk to both sides, and 3 times each sides. Data will report as mean values. (unit of measure: degree, °)	Day 2
Isometric strength and rate of force development of shoulder internal and external rotation	Subjects supine with the test side positioned at 90° shoulder abduction and 90° elbow flexion in scapular plane. The K-pull Digital Dynamometer (Kinvent, Montpellier, France) will used for trials. Subjects would be asked to hold the digital dynamometer and perform the maximum isometric contraction strength test of shoulder internal and external rotation for 5 seconds at their maximal exertion. Shoulder internal and external rotation will be performed 3 times each, with a 30-second rest interval. The maximum isometric strength of the shoulder internal and external rotation is calculated by dividing the maximum strength by the body weight and multiplying by 100%, and the average of the 3 measurements will be calculated. The shoulder external/internal rotation strength ratio would also be calculated. The force rate data are averaged using the values in the time ranges of 0-50, 0-100, 0-150, 0-200, and 0-300 milliseconds.	Day 2
Scapulothoracic and glenohumeral joint control ability	Subjects will supine with the tested side positioned at 90° shoulder abduction and 90° elbow flexion in scapular plane, and then actively perform 60° shoulder internal rotation. The test consist of two parts. The first part observe whether the scapula is excessively anteriorly rotated; if so, one point will be given. The second part observe whether the subject has difficulty breathing, difficulty moving, inability to reach 60° shoulder internal rotation, excessive anterior rotation of the humerus, fatigue, or a need for external feedback and assistance; if so, one point will be given. Each item can be scored as one point. A score of 1 in the first part or more than 3 points in the second part (out of a total of 7 points) is considered a positive test result. Positive or negative result will be recored.	Day 2
Upper quarter Y-balance test performance	Subjects will remove their shoes and socks for the test. The test begin with a push-up position with both shoulders flexed at 90°, elbows extended, and both legs shoulder-width apart. The subject will perform maximum movement in each direction from the non-test side (moving end), returning to the starting position in the same motion to complete the test. Participants will be asked to perform the test 3 times each direction, with a 30-second rest between each test.The maximum distance of movement was standardized by dividing by the upper limb length, and the standardized results for each direction are summed and averaged to obtain the overall score. (unit of measure: %)	Day 2
Posterior shoulder endurance	After the subject positioned in 90° shoulder flexion position in standing, a Thera band is fixed at the same level as the shoulder, which is the starting position. The endpoint is defined as a position with 90° external rotation and 90° abduction of the shoulder. Male subjects use a green resistance band (2.1 kg), while female subjects use a red resistance band (1.7 kg). The subject is asked to repeat the movement between the starting and endpoint positions until the subject is unable to maintain the rhythm or complete the movement after two verbal reminders. The beat starts at 60 bpm and increases by 30 bpm every 20 seconds, up to a maximum of 150 bpm. (unit of measurement: seconds)	Day 2

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Degree of shoulder and scapular kinematics during arm elevation	The kinematics is assessed using an electromagnetic motion tracking system (VIPERTM, Polhemus, USA) to collect the glenohumeral elevation, horizontal abduction/adduction, internal/external rotation, scapulothoracic retraction/protraction, upward/downward rotation, anterior/posterior tilt during arm elevation. During the test, participants performed 5 arm elevations, with 60 seconds of rest between each trial. Data will report as mean values for each trial. (unit of measure: degree, °)	Day 1
Amplitude of the activation of glenohumeral and periscapular muscles during arm elevation	The muscle activation amplitude of the upper trapezius, lower trapezius, serratus anterior, latissimus dorsi, pectoralis major, biceps brachii, and triceps brachii would be recorded during arm elevation. During the test, participants performed 5 arm elevations, with 60 seconds of rest between each trial. The data will be reported as mean values for each trial. (unit of measure: percentage, %)	Day 1

Collaborators and Investigators

• Sponsor: National Yang Ming Chiao Tung University

Study record dates

Study Major Dates

• Study Start (Actual): January 29, 2026
• Primary Completion (Estimated): January 29, 2027
• Study Completion (Estimated): January 29, 2027

Study Registration Dates

• First Submitted: March 12, 2026
• First Submitted That Met QC Criteria: April 15, 2026
• First Posted (Actual): April 22, 2026

Study Record Updates

• Last Update Posted (Actual): April 22, 2026
• Last Update Submitted That Met QC Criteria: April 15, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: shoulder pain, tennis, kinematics, electromyography
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Musculoskeletal Diseases; Joint Diseases; Arthralgia; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Shoulder Pain
• Other Study ID Numbers: NYCU114005AF