A dynamic extensor brace reduces electromyographic activity of wrist extensor muscles in patients with lateral epicondylalgia.
METHODS
Semiexperimental study.


OBJECTIVE
To investigate the effect of an external wrist extension force on extensor muscle activity during hand gripping in patients with lateral epicondylalgia.


BACKGROUND
Lateral epicondylalgia or "tennis elbow" is a common, often disabling ailment affecting millions of people. An optimal treatment strategy remains to be identified. The use of an external wrist extension force may reduce the extensor muscle activity during gripping in these patients.


METHODS
Muscle activity of the extensor carpi radialis brevis (ECRB), extensor digitorum communis (EDC), and extensor carpi radialis longus (ECRL) was measured using surface EMG. Subjects gripped at an intensity of 10%, 20%, and 30% of the maximum voluntary contraction (MVC) force with and without the dynamic extensor brace and with and without an applied external wrist extension force of 1%, 2%, and 3% of MVC.


RESULTS
At all levels of MVC gripping, the EMG signal of the ECRB and EDC were significantly lower for gripping with than without brace. An extension force of 3% of the MVC force significantly reduced the EMG signal of all muscles in almost all measurement conditions.


CONCLUSIONS
The results of this study indicate that the dynamic extensor brace as well as the external extension force significantly reduced the EMG signal of the wrist extensor muscles during gripping in patients with lateral epicondylalgia. Based on these results, the dynamic extensor brace could be a promising new intervention for lateral epicondylalgia.
Faes
Miriam
M
Department of Physiology, University Medical Centre, Nijmegen, The Netherlands.
van Elk
Niek
N
de Lint
Jan A
JA
Degens
Hans
H
Kooloos
Jan G M
JG
Hopman
Maria T E
MT
D000328:Adult; D001915:Braces; D004576:Electromyography; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D013716:Tennis Elbow / Q000503:physiopathology / Q000628:therapy*; D014955:Wrist Joint / Q000502:physiology*