Study of the scapular muscle latency and deactivation time in people with and without shoulder impingement

Abstract Changes in muscle activities are commonly associated with shoulder impingement and theoretically caused by changes in motor program strategies. The purpose of this study was to assess for differences in latencies and deactivation times of scapular muscles between subjects with and without s...

Full description

Saved in:
Bibliographic Details
Published in:Journal of electromyography and kinesiology 2013-04, Vol.23 (2), p.469-475
Main Authors: Phadke, Vandana, Ludewig, Paula M
Format: Article
Language:English
Subjects:
Adult
Female
Humans
Male
Motor control
Movement
Movement disorders
Muscle Contraction
Muscle, Skeletal - physiopathology
Physical Medicine and Rehabilitation
Reaction Time
Scapula - physiopathology
Shoulder Impingement Syndrome - physiopathology
Shoulder Joint - physiopathology
Shoulder pain
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Changes in muscle activities are commonly associated with shoulder impingement and theoretically caused by changes in motor program strategies. The purpose of this study was to assess for differences in latencies and deactivation times of scapular muscles between subjects with and without shoulder impingement. Twenty-five healthy subjects and 24 subjects with impingement symptoms were recruited. Glenohumeral kinematic data and myoelectric activities using surface electrodes from upper trapezius (UT), lower trapezius (LT), serratus anterior (SA) and anterior fibers of deltoid were collected as subjects raised and lowered their arm in response to a visual cue. Data were collected during unloaded, loaded and after repetitive arm raising motion conditions. The variables were analyzed using 2 or 3 way mixed model ANOVAs. Subjects with impingement demonstrated significantly earlier contraction of UT while raising in the unloaded condition and an earlier deactivation of SA across all conditions during lowering of the arm. All subjects exhibited an earlier activation and delayed deactivation of LT and SA in conditions with a weight held in hand. The subjects with impingement showed some significant differences to indicate possible differences in motor control strategies. Rehabilitation measures should consider appropriate training measures to improve movement patterns and muscle control.
ISSN:1050-6411
1873-5711
DOI:10.1016/j.jelekin.2012.10.004