Core Strengthening and Scapular Stability

Summaries Courtesy of Strength and Conditioning Research Review

The study

Comparison of spine motion and trunk muscle activity between abdominal hollowing and abdominal bracing maneuvers during prone hip extension, by Suehiro, Mizutani, Watanabe, Ishida, Kobara, and Osaka, in Journal of Bodywork & Movement Therapies, 2014

What is the background?

Prone hip extension is an exercise often placed in the rehabilitation programs of individuals with lower back or hip injuries. However, excess anterior pelvic tilt or lumbar extension can occur when it is performed improperly. Two methods that are commonly used for stabilizing the lumbo-pelvic complex are abdominal bracing (AB) and the abdominal hollowing maneuver (ADIM). However, which is best for stabilizing the lower back and pelvis during the prone hip extension exercise has not previously been explored.

What did the researchers do?

The researchers compared spinal motion and trunk muscle activity during the prone hip extension when performing either the AB or ADIM approaches to lumbo-pelvic stability.

What did the researchers find?

The control condition displayed the greatest lumbar extension measurement (7.3 ± 3.5 degrees) and that there were significant differences between the control and AB and between the control and ADIM. However, there were no differences between AB and ADIM.

The control condition displayed the greatest degree of anterior pelvic tilt (5.4 ± 3.3 degrees) and there were significant differences between the control and ADIM and between the control and AB. Again, however, there were no differences between AB and ADIM.

Overall abdominal muscle group EMG activity was greatest in AB followed by ADIM, followed by the control. These differences between conditions were all significant. In respect of individual muscles, external obliques EMG activity was greater in AB than in ADIM, extensor spinae EMG activity was greatest in the control, followed by AB and then ADIM.

What are the practical implications?

Both abdominal hollowing (ADIM) and abdominal bracing (AB) can be used to reduce spinal motion (excess anterior pelvic tilt and lumbar extension) during the prone hip extension exercise. However, abdominal bracing leads to greater abdominal muscle activity than abdominal hollowing and may therefore be better for training the abdominal musculature.


The effects of active scapular protraction on the muscle activation and function of the upper extremity.
Yang, Lee, Lee, Jeon, Han, and Han, in Journal of Physical Therapy Science, 2014

 

Scapular protraction

What is the background?

Upper body function is achieved through both proximal and distal movements. Proximal stability is attained through muscular control of the scapula. Thus, it is possible that when the scapula is not ideally placed, upper body function may be impaired.

What did the researchers do?

The researchers wanted to understand the differences in upper body function (as measured by grip strength and the muscle activity of the shoulder girdle and arm muscles) when the scapula is ideally positioned using active scapular protraction and when it is not.

What did the researchers find?

With active protraction of the scapula, grip strength of the trial group increased significantly.  Similarly, muscle activation of the serratus anterior, upper trapezius, flexor carpi ulnaris, flexor carpi radialis, and palmaris longus muscles all significantly increased as a result of active scapular protraction. There was a non-significant trend for the muscle activation of the infraspinatus to increase as well.

What are the practical implications?

By placing the scapula in an ideal position using active scapular protraction, it is possible to improve upper body function (as measured by grip strength and the muscle activity of the shoulder girdle and arm muscles).

Reviews provided in partnership with Strength and Conditioning Review.

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