Rotator cuff tendinopathy alters the muscle activity onset and kinematics of scapula

Hio Teng Leong, Gabriel Yin fat Ng, Shing Chung Chan, Siu Ngor Fu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

12 Citations (Scopus)


This study aimed to determine whether alteration in scapular kinematics is associated with deficits in the activity onset of scapular muscles. Forty-three male volleyball players (17 asymptomatic and 26 with RC tendinopathy) joined the study. Three-dimensional scapular kinematics was quantified using an acromial marker cluster method. The activity onset of the upper (UT), middle (MT), and lower trapezius (LT), and serratus anterior (SA) during arm abduction was assessed with electromyography. Athletes with RC tendinopathy demonstrated less scapular upward rotation (6.6 ± 2.3 vs. 8.2 ± 1.1°, p = 0.021) in the early phase of shoulder abduction from 0° to 30° when compared to asymptomatic athletes. The tendinopathy group had delayed activity onset of LT (14.1 ± 31.4 ms vs. 74.4 ± 45.1 ms, p < 0.001) and SA (−44.9 ± 26.0 ms vs. 23.0 ± 25.2 ms, p < 0.001) relative to UT when compared to the asymptomatic group. In asymptomatic athletes, earlier activity onset of MT and LT relative to UT was associated with more scapular upward rotation during 0–30° of abduction (r = 0.665, p = 0.021) and 30–60° of abduction (r = 0.680, p = 0.015), respectively. Our findings showed the control of the scapular upward rotation is related to the activity onset of the scapular muscles in athletes.
Original languageEnglish
Pages (from-to)40-46
Number of pages7
JournalJournal of Electromyography and Kinesiology
Publication statusPublished - 1 Aug 2017


  • Activity onset
  • Overhead athletes
  • Rotator cuff tendinopathy
  • Scapular kinematics
  • Scapular muscles

ASJC Scopus subject areas

  • Neuroscience (miscellaneous)
  • Biophysics
  • Clinical Neurology


Dive into the research topics of 'Rotator cuff tendinopathy alters the muscle activity onset and kinematics of scapula'. Together they form a unique fingerprint.

Cite this