Muscle Activation: Using EMG To Improve Movement

At every physical therapy office, gym, CrossFit box, and Pilates studio people are trying to improve fitness and strength.

To rehab from injury, get in shape, perform a PR clean, or improve posture you need to improve your strength and motor control.

Improving strength takes effort.  

If you are going to put in the time and energy to "get stronger" you want to make sure that you are getting the most out of your workouts right...

...nobody wants to put in hard workouts day after day without REAL results. 

In rehab and fitness, it is essential to perform movements correctly without compensations in order to maximize gains.

So, how do you know you are using your muscles equally when you strength train?  Even though you are doing a specific movement to improve your quadriceps strength for instance, are you sure that those specific muscles are doing the work?

Right versus Left quadriceps activation with a single leg step down

Muscle Biofeedback: EMG

There fortunately is a way to know for sure that the right muscles are working during your training...it's called electromyography or EMG.  

EMG technology has been around for a number of decades; however, recently it has made its way into the everyday health and rehabilitation market.  EMG analysis uses small electrodes (sensors) that are placed on the target muscles being evaluated in order to "pick up" electrical signals that are emitted from the muscles during contractions.

These small changes in current are amplified using specialized software which creates tracking tools and biofeedback graphs to help train muscle activation.  It looks something like this...



Often times, when we exercise, although we think we are using equal muscle activation and proper symmetry the reality is that some asymmetry is normal.  Now, too much difference in side to side activation will limit performance and lead to either overuse or injury. 

How Is EMG Used For Rehabilitation At Competitive EDGE PT?

At Competitive EDGE Physical Therapy in San Jose we use EMG biofeedback everyday. In fact, EMG training is built in to our specialized running and recovery programs as the first step in training optimal movement. 

Frequently, runners have gluteus maximus and medius weakness leading to knee collapse, pelvic drop, or hip adduction.   Another reason for these movement impairments however could be a lack of gluteal "activation".  Although many runners do the right exercises for training, they may have been using the wrong muscles because they simply don't know how to access the gluteal muscles.

EMG training in this instance is a true game changer.  Having real-time feedback on muscle activation allows true motor learning.

A phrase I hear often from runners and multi-sport athletes that use EMG for the first time...

"I have been doing bridges for months...and I haven't even been using my glutes!"

Although this causes frustration at first, there tends to be a quick progression of activation and strength once EMG is used for biofeedback.

Post-Operative Rehabilitation

Another common usage of EMG is for post-operative rehabilitation.  Often after surgery, atrophy occurs leading to muscle weakness.  In addition, swelling temporarily "shuts off" the ability to activate the atrophied muscle.  EMG works great to help improve proper control of muscle contraction after surgery. 

Plus, later in rehabilitation, we can use EMG software to compare muscle activation during a specific movement such as a squat.  This data allows tracking of muscle usage to help improve technique and balance. 

Here is an example comparing quadriceps (VMO) activation during double leg squatting 9 months post-op ACL (ACL surgery was on the right side)... 

Getting The Most Out Of Training And Rehab

If you are looking to maximize your time in physical therapy or looking to improve your movement skills, EMG can help take your training to the next level.

For those recovery from injury, EMG training is essential to restoring optimal movement. We are all pressed for time and want to get the most out of the time we devote to our bodies and health.  

For those of you in the San Jose area be sure to check out www.compedgept.com for more information on EMG training.  

Written by:  Kevin Vandi DPT, OCS, CSCS

Serving: San Jose, Los Gatos, Almaden, Campbell