Electromyographical Assessment of Passive, Active Assistive, and Active Shoulder Rehabilitation Exercises
Received 8 October 2008; accepted 4 January 2010.
Objective
To determine the electromyographical (EMG) activation levels of shoulder musculature during early rehabilitation exercises to regain active range of motion.
Fine-wire (supraspinatus and infraspinatus) and surface (anterior deltoid, upper trapezius, lower trapezius, and serratus anterior) electrodes recorded EMG activity from each muscle during 12 therapeutic exercises completed during a single testing session in random order.
Main Outcome Measure
EMG root mean squared amplitude normalized to a percentage of maximum voluntary contraction (% MVC).
Results
Passive exercises generated the lowest mean EMG activity (<10%) for all muscles studied. The standing active shoulder elevation exercises generated the greatest mean EMG activity with an upper boundary of 95% CI (40% MVC). Overall the active-assistive exercises generated a small (<10%) increase in muscle activity compared with the passive exercises for the supraspinatus and infraspinatus muscles, which was not a significant increase (P > .05).
Conclusion
This electrophysiological data in normal volunteers suggest that many exercises used during the early phase of rehabilitation to regain active elevation do not exceed 20% MVC. Progression from passive to active-assisted can potentially be performed without significantly increasing muscular activation levels exercises. Upright active exercises demonstrated a consistent and often a statistically significant increase in muscular activities supporting that these exercises should be prescribed later in a rehabilitation program.
aDepartment of Rehabilitation Sciences, Division of Athletic Training, Rm 210C CT, Wethington Building, University of Kentucky, 900 S. Limestone Street, Lexington, KY 40536-0200⁎
bDepartment of Rehabilitation Sciences, Division of Athletic Training, University of Kentucky, Lexington, KY†
cDivision of Physical Therapy, University of Kentucky, Lexington, KY‡
Address correspondence to: T.L.U.
Disclosure Key can be found on the Table of Contents and at www.pmrjournal.org
ABSTRACT