Muscle Fatigue and Scapular Sensorimotor System

Not Applicable

Completed

Conditions: Muscle; Fatigue

Registration Number: NCT03066102

Lead Sponsor: National Yang Ming Chiao Tung University

Brief Summary: The aims of this study are to investigate the effects of scapular muscle fatigue on scapular joint position sense and neuromuscular performance (scapular muscle strength, the kinematics data and muscle activity of shoulder during scaption (arm elevation in the scapular plane)). The investigators hypothesize that scapular muscle fatigue would increase scapular reposition error and affect neuromuscular performance of the scapular during scaption.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 30

Inclusion Criteria

no shoulder, cervical, and thoracic spine pain within six months
negative for subacromial impingement test
normal range of motion of glenohumeral joint

Exclusion Criteria

history of dislocation, fracture, or surgery of shoulder joint
history of central nervous system disorder, rheumatoid arthritis, shoulder osteoarthritis, or cervical radiculopathy

Study & Design

Study Type: INTERVENTIONAL

Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
Change From Baseline in Scapular Proprioception	through fatigue intervention completion, an average of 20 minutes in female subjects and 40 minutes in male subjects	Test the ability of active re-position the scapula from neutral to 90% range of protraction, and elevation.
Change From Baseline in Muscle Activation During Scapular Proprioception	through fatigue intervention completion, an average of 20 minutes in female subjects and 40 minutes in male subjects	Test the ability of muscle activation (upper trapezius, lower trapezius, and serratus anterior) during active re-position the scapula from neutral to 90% range of protraction, and elevation. Muscle activation during active re-position would divide into muscle activation during maximum voluntary isometric contraction (MVIC), present in percent.

Secondary Outcome Measures

Name	Time	Method
Change From Baseline in Scapular Muscle Strength	through fatigue intervention completion, an average of 20 minutes in female subjects and 40 minutes in male subjects	use dynamometer to detect the force of maximum isometric voluntary contraction of upper trapezius, lower trapezius and serratus anterior
Change From Baseline in Shoulder Kinematics Data During Shoulder Elevation in the Scapular Plane	through fatigue intervention completion, an average of 20 minutes in female subjects and 40 minutes in male subjects	use Liberty to detect the motion of spine, humerus, and scapula during shoulder elevation in the scapular plane (scaption)
Change From Baseline in Scapular Muscle Activity During Shoulder Elevation in the Scapular Plane	through fatigue intervention completion, an average of 20 minutes in female subjects and 40 minutes in male subjects	Test the ability of muscle activity (upper trapezius, lower trapezius, and serratus anterior) during shoulder elevation in the scapular plane (scaption). Muscle activation during scaption would divide into muscle activation during maximum voluntary isometric contraction (MVIC), present in percent.
Change From Baseline in Scapular Muscle Recruitment Timing During Arm Elevation in Scapular Plane	through fatigue intervention completion, an average of 20 minutes in female subjects and 40 minutes in male subjects	Test the ability of muscle onset timing (upper trapezius, lower trapezius, and serratus anterior) during shoulder elevation in the scapular plane (scaption). Onset timing was determined by EMG signals bigger than resting signals plus 3 times standard deviations. Origin was set at onset of kinematics data of glenohumeral joint.