We know from our studies in general anatomy that every muscle and visceral organ is innervated by our nervous system. Our nervous system is divided into two systems the somatic and autonomic. We are more familiar with the autonomic system because it is subdivided into the parasympathetic and sympathetic. The autonomic system is what creates the flight or fight response in our bodies. The parasympathetic and sympathetic systems are more complex systems to understand because the nerve signal is not sent directly to the organ, gland or artery/vein first. The signal goes through a ray of pathways until the signal is finally delivered to its desired destination. The somatic system is less complex because the nerve signal is sent straight from the axon to the muscle. (Figure 1.11) In the health and fitness profession we are more concerned with the somatic system because our lively hood is based on shaping and retraining muscles.
Now if we understand the basics of the nervous system then understanding neural firing can be very easy. We need to look at neural firing as the neuron that sends signals through our nerves out to the muscles or viscera. The neuron is like a messenger. The neuron carries the message being sent from the muscle/viscera to the brain via the spinal cord back down to the muscle/viscera. So if there is a muscle spasm or an organ is diseased than the neuron can not fire as quickly or may not fire at all. For an example, multiple sclerosis patients have lost their ability to fire neurons effectively because of a decrease in the number of ACH (acetylcholine) being produced at the neuromuscular junction. This is a more complex example but demonstrates the concept of neural firing very well. We will now look at how this applies to functional movement which is our main concern.
To begin we need to understand a few concepts about how our nervous system helps control functional movement patterns. The central nervous system is the command center that controls and regulates all movement patterns. Say we wanted to pick up a pencil on our desk, before the action can be preformed a signal is sent to our brain which tells the brain to conduct an action and then the signal is sent back down via the spinal cord to the muscles before the pencil is even picked up. The central nervous system directs preprogrammed patterns of movement that can be modified to react appropriately to gravity, ground reaction forces, and momentum. This concept is extremely important when we look at designing a training, reconditioning or rehabilitation program. With core stabilization we will be able to retrain muscle groups to fire correctly when doing functional exercises or activities. When a muscle becomes injured other muscle groups will protect that particular injured muscle while it heals but at the same time the other muscle groups adapt in order to perform regular movements. For example, research has demonstrated that the transverse abdominus (a major intrinsic stabilizer of the lumbar spine) has shown decreased neural firing in individuals complaining of low back pain. Therefore these individuals will have relied on the psoas, erector spinae and the superficial abdominal muscles to provide stability to the lumbo-pelvic-hip complex. And what we see in individuals with low back pain is poor posture, inadequate stabilization and decreased neuromuscular efficiency as a result of decreased core strength.
Before I had mentioned that we would look at ways to test certain muscle groups in order to see if they were weak or strong. This correlates with neural firing and the lumbo-pelvic-hip complex which is the main focus surrounding core stabilization. These are very basic ways to test our clients or patients muscles and how we can send a proprioceptive signal into the muscle belly to make the muscle fire again.
A proprioceptive signal is where we can send a stimulus into the muscle in order to wake it up again. The proprioceptive signal is sent into the golgi tendon organ of the muscle which tells the muscle to either contract or relax.
Take the gluteus maximus and medius muscles. Both muscles cause extension of the hip. To test the gluteal muscles have your client or patient stand so that they are facing forward. Then stand behind the client or patient. Have your client or patient stand next to a wall or chair encase they need something for balance. Ask them to raise one leg to 90 degrees with the knee bent and then repeat to the other side. When the leg is brought up to 90 degrees we are looking to see if the opposite gluteal muscles dip down. This simple test indicates a problem or a weakness with the gluteus medius muscle. Since we might not choose to do this test on everyone we could look at it from another stand point. Say you have a client or patient who complains of a muscle spasm when doing hip extension exercises on a therapeutic ball or on a machine, our first instinct is to stop and stretch the muscle. But what if we sent a proprioceptive signal to the muscle instead of stretching the muscle? What we are able to do is retrain the muscle and get the muscle firing again hence decreasing the spasm. Now this is not going to be a pain-free movement for your client or patient so please address that first. Next go ahead and have your client or patient lie on the uninvolved side with their backside facing you. Have your client or patient lie on a mat on the floor and not a bench to ensure safety. Next place your thumb right on the ischial tubersoity (also known as your butt bone) and ask your client if that causes the same discomfort. Next ask your client or patient to perform hip extension while you maintain your contact and resist them from performing extension. Hold for about five seconds then have them relax and repeat five times. Since the area will be inflamed and sore for about 24 to 48 hours have your client or patient ice at home for about twenty minutes and have them do this three times before going to bed for the evening. The next time your client or patient performs any action that requires hip extension the gluteus maximus and medius will fire before any other muscle fires which is what we want to happen.
Another test we can look at stems from the psoas and quadratus lumborum muscles. We already know that the two muscles aid in core stabilization and their primary muscle action is hip flexion. For this test you would want to ulitize a bench since you will be adding a stretch into the test. Have your client or patient lie on their back while you stand to the side of the bench. If your client or patient feels unsteady on the bench have them grasp the bench for additional support. But this may be difficult because the test requires them to use their hands. Ask the client or patient to bring one knee into their chest and hold have them hold it there with their hands for about five seconds and then have them relax. What you are looking for is to see if the knee bends or comes up toward the ceiling of the straight leg. If this happens it indicates that they have a tight psoas or quadratus lumborum on the straight leg side. Repeat this to the opposite side. You can add to this test by taking the straight leg off to the side of the bench keeping the rest of the body on the bench and put one hand over our client’s or patient’s hands while your other hand is placed on their thigh just above the knee. Next push gently on your client’s or patient’s hands while you also push the other leg towards the floor. Once they feel a stretch hold for five seconds. Then continue to maintain the exact position as you continue to push the leg to the floor. Hold again for five seconds once they feel the stretch and then go into one more stretch from there. You do this three times and every time you never release the stretch until the third stretch is completed. What you are doing is sending a signal into the muscle by stretching instead of applying a physical contact to the area. Again, since you might not choose to do this test with everyone of your client’s or patient’s you might notice that they have a tight psoas or quadratus when they have difficulty bringing their knee to their chest or when they try to bring both knees to their chest during stretching. This test also works as a great stretch for these two muscles since they lie deep in the abdomen and you can not physically contact the muscle belly.
One other test we can look at is when we have a client or patient complain of knee pain on the lateral side (outside part of the knee). Now the muscle most likely to be effected here is the iliotibial band. This muscle has no main connection with our core but if we look at the effect it has when it becomes too tight the connection becomes clear. If we put our hands at our sides and run them up to where we feel our hips then we have just illustrated where the iliotibial band is located. The iliotibial band is a thin muscle that starts up by the hip and runs down to the fibula. We usually see tight iliotibial bands in runners. Now if our iliotibial band is tight or in spasm then it directly effects the movement surrounding the hip, the pelvis and right up into our low backs. You can test the iliotibial band by having the client or patient side lying on a bench with you standing behind them for support. Have them lie on the uninvolved side. Next ask your client or patient to abduct their leg and extend the leg behind them. What you are looking for is the leg to stop or cause discomfort to the client or patient when performing this movement. Once they can not go any further, place one hand on their pelvis and the other on their thigh just above the knee. Then bring them into a stretch and hold once the stretch is felt for five seconds. Again you are going to maintain that position as you bring them further and further into a stretch. Repeat this three times before you have the client or patient completely relax. If you choose not to do it this way, you can also have your client or patient lie on their side on the floor. Again have them lie so the involved side is up and so their pelvis is perpendicular to the floor. Place both of your thumbs over their hip joint and apply some pressure. Remember you never want to cause any harm to our client or patient when doing any of these techniques. While you maintain your contact ask your client or patient to bring their knee to their nose and then have them fully extend from that position. This is going to be uncomfortable. Perform this exercise slowly and repeat five times. With this technique you are able to send a signal into the muscle telling the muscle to relax and stretch.
What I have illustrated here is three techniques that you can use to send a proprioceptive signal into the injured muscle. Even though they are simple techniques they are very useful with most of our clients and patients when it comes to retraining the injured muscle.
For more information or questions concerning this topic contact +Heather Gansel.