Muscle Fatigue and Scapular Sensorimotor System
Phase: NA
Conditions: Muscle; Fatigue
Sponsor: National Yang Ming Chiao Tung University

 
 
Date: 3/27/2018 
The Effects of Scapular 
Muscle Fatigue on Scapular 
Sensorimotor System 
 
 
Author: Guo-Fong Luo 
 
Adviser: Yi-Fen Shih, Ph.D. 
 
 
 
 
 

 
 
 
2
Study Protocol  
l 
Objective: To investigate the effect of scapular muscle fatigue on 
scapulothoracic joint position sense and neuromuscular performance. 
l 
Design: Cross-sectional study design 
l 
Methods: We recruited 30 healthy adults (15 males and 15 females aged 
23.6 ±1.8 years old in average) for the study. They received the 
measurements of scapulothoracic joint position sense (reposition error) 
during the elevation and protraction tasks, muscle strength, and scapular 
kinematics and muscle activation (amplitude and recruitment timing) 
during scaption (arm elevation in scapular plane) before and after a fatigue 
protocol. Our fatigue protocol was a task designed to exhaust scapular 
muscles including upper, lower trapezius, and serratus anterior. The task 
required the participants holding the modified push-up plus position for 
two (female) or three (male) minutes for five to ten repetitions or until 
they could only longer hold the position. The repeated measured analysis 
of variance (ANOVA) was used to assess the effects of fatigue on scapular 
reposition errors, muscle strength, scapular kinematics, muscle activation, 
and recruitment timing. The level of statistical significance was set at P < 
0.05.   
Statistical Analysis Plan  
l Two-way repeated measures analysis of variance (ANOVA) for kinematics 
data and muscle activation during scaption  
l Statistical significance for all comparisons at P < .05, and adjusted to 0.00625 
and 0.0083 using Bonferroni method for post separate one-way repeated 
measures analysis of variance