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Changes in Shoulder Kinematics Following an Isokinetic Fatigue Protocol in Tennis Players

NCT04900922 · Status: COMPLETED · Type: OBSERVATIONAL · Enrollment: 26

Last updated 2022-09-06

No results posted yet for this study

Summary

A typical tennis match can take 1 to 5 hours. Tennis serve can be divided into eight stages and three phases. Injuries usually happen in the cocking stage and acceleration phase of the serve, where it requires large shoulder range of motion and proper scapular motion, including sufficient scapular upper rotation, external rotation, and posterior tilt to produce a powerful serve. Altered shoulder kinematics are associated with shoulder injuries in tennis players, including delayed shoulder horizontal adduction, and early external rotation. Due to the long duration and repetition of activity in a match, fatigue may happen and result in decreases in sensory input, passive range of motion, ball speed, and muscle strength. These changes may further lead to altered glenohumeral and scapular kinematics. However, previous studies mainly focused on the effects of fatigue on scapular kinematics in constrain movements and applied different fatigue protocols, which lead to inconsistent results. Tennis serve in cocking stage and the acceleration phase require high activation of shoulder external rotators and internal rotators, including infraspinatus, pectoralis major, subscapularis, latissimus dorsi and serratus anterior. However, to our knowledge, no study has investigated how fatigue of shoulder rotators influences shoulder kinematic as well as scapular kinematics during the late cocking stage and acceleration phase of tennis serve. Therefore, the investigators aim to investigate whether fatigue of shoulder rotator affects shoulder kinematics in healthy tennis players during the late cocking stage and acceleration phase of tennis serve.This is a single group, pretest-posttest measurement study. In a fatigue protocol, investigators use an isokinetic dynamometer to induce fatigue of shoulder rotators. Outcome measures will be tested before and after the fatigue protocol, including peak torque of shoulder rotators, humerothoracic kinematics, scapulothoracic kinematics, and median power frequency recorded by a surface electromyography. Peak torque of shoulder rotators will be measured with an isokinetic dynamometer. Surface electromyography will be used to measure peripheral muscle fatigue by maximum voluntary isometric contraction. Humerothoracic kinematics and scapulothoracic kinematics during a functional tennis serve and scaption will be collected with a motion capture system.

Conditions

Interventions

DEVICE

isokinetic dynamometer

We will use an isokinetic dynamometer to conduct the concentric isokinetic fatigue protocol. The start position is shoulder abduction 90°, elbow flexion 90°and range of motion is set from 0 ° (internal rotation) to 90 ° (external rotation) under 120°/s. To calculate maximum torque of shoulder external and internal rotation, the subject will perform maximum isokinetic test 5 times before fatigue. Fatigue protocol include 10 sets, and each set include 32 repetitions with 30 seconds of rest between sets. The fatigue protocol will be stopped under three conditions: 1. the torque decreases 50% of maximum torque three times in one set or 2.rating of perceived exertion (RPE) abrove 15 and players can not perform the fatigue protocol or 3. finish the whole test.

Sponsors & Collaborators

  • Fu Jen Catholic University

    collaborator OTHER

  • National Yang Ming Chiao Tung University

    lead OTHER

Principal Investigators

  • Yin-Liang Lin, PhD · National Yang Ming Chiao Tung University

Eligibility

Min Age
20 Years
Max Age
45 Years
Sex
ALL
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2021-11-10
Primary Completion
2022-03-05
Completion
2022-03-05

Countries

  • Taiwan

Study Locations

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Diseases

Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT04900922 on ClinicalTrials.gov