Dear Strength Coach Personal Trainer,
While I do believe that it is more accurate to refer to specific muscles stabilizing or mobilizing ROLES during specific phases of a given motor pattern (check the late Mel Siff’s blog for a good discussion on this topic), certain muscles are, due to their position deeper and closer to the joints, more suited for a stabilizing than a mobilizing function (The Flexible Periodization Method has a table with reference to this topic).
These muscles are often characterised by tonic activity (hence the term tonic stabilizers) and typically are smaller and not that strong muscles.
While it is impossible to “isolate” muscles in the sense that a certain muscle is the only muscle active, we can “emphasize” a certain muscle (or at least a functional group) as the agonist through single joint exercises. In the case of single joint exercises to emphasize tonic stabilizers, we often choose lower loads and higher reps, to ensure that the contraction is performed by the “weaker” stabilizers without the stronger phasic muscles taking over. We also often use slower tempos, because these tonic stabilizers tend to be slow twitch dominant muscles.
However, according to Lebensson C., the stabilizers are suited to worked with an eccentric-isometric function during movement and in certain cases, we can design exercises that emphasize speed of OTHER muscles, while having the targeted tonic stabilizer working eccentric-isometric.
Watch this video to learn two different exercises that engage the gluteus medius with a direct slow contraction or with an indirect faster contraction.
Tempo contrasts and combination exercises are covered in my new course, “How to Double the Effect of Your Bodyweight Training” that will be available from tomorrow, Nov 15th, to our valued subscribers only.
To Your Success,