Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 21 (3), 478-82

Shoulder Muscle Activation and Fatigue During a Controlled Forceful Hand Grip Task


Shoulder Muscle Activation and Fatigue During a Controlled Forceful Hand Grip Task

O Alizadehkhaiyat et al. J Electromyogr Kinesiol.


Purpose: Reliable electromyographic evaluation of the shoulder in common painful conditions is a major challenge due to a reduced range of movement and pain-related muscle inhibition. This study investigates the use of a hand grip task for the assessment of shoulder muscle activation.

Methods: Muscle activity and fatigue for supraspinatus and infraspinatus muscles were measured in 16 healthy controls using fine-wire electrodes during a controlled gripping task at 50% of maximum voluntary contraction, in a standardized sitting and arm position. Changes in muscle activity and fatigue were measured by the time-slope of root mean square amplitude and median frequency, respectively.

Results: A significant positive amplitude slope (p<0.01) was found for both supraspinatus and infraspinatus, indicating that the task resulted in increasing muscle activity. Judging by the median frequency slope, there was no sign of fatigue progression.

Conclusion: A standardized hand grip task in a neutral position activates key rotator cuff muscles. This might provide a method for electromyographic assessment of shoulder girdle muscles which avoids problems due to pain-related limitation of movement, and might be useful in the development and monitoring of shoulder rehabilitation strategies.

Similar articles

See all similar articles

Cited by 4 articles

LinkOut - more resources