Often during our warm up routines that we have our clients perform at the gym, clients will mention feeling a stretch in certain muscles during some of the drills. This will then lead to an explanation of what it is we are hoping to accomplish during the warm up and what you should be feeling. We go through several drills prior to a more dynamic warm up that will lead into the strength portion of your workout. The drills are specifically designed to increase mobility through a joint. You need a certain amount of mobility or the ability to move your joints through a normal range of motion. But what is mobility and what is flexibility?
In a nutshell mobility is the ability of the joint to move through a range of motion and flexibility is the ability of the muscle to stretch to allow movement. In this article we are going to deal with mobility. Physical Therapist Gray Cook's (1) analysis of the body and its function is by means of a series of joints. Each joint has a specific function and is prone to specific dysfunctions. He devised a table that describes the body on a joint-by-joint basis from the bottom up:
Lumbar Spine stability
Thoracic Spine mobility (upper back)
Gleno-humeral stability (shoulder)
As you can see from this chart the joints alternate between mobility and stability. Injuries and problems occur when the joints lose the ability to perform their specific function be it mobility or stability. For our clients we will go through ankle range of motion testing. To do this we have clients kneel on the floor in a lunge position. We then ask them to push forward with their knee over their toe, keeping the heel down. We then used a stick from knee to ground to measure distance the knee moved past the toes. We know that a good range of motion for the ankle is 4″ or more past your toe. If your ankle lacks the mobility it needs, when we ask you to perform exercises such as squats or lunges, you either will not be able to perform these exercises correctly , or you will get knee pain when you do perform them. For this reason, we have included 3 specific ankle mobility drills (ankle rolls, knee to wall, toes on foam roller) in our warm up routine. We also know in our own unscientific test that performing these ankle drills does work. We had one client go from 1/2″ ankle mobility to 3″ ankle mobility in both ankles in a 3 month period.
The hips must be mobile in all planes of movement (front to back, side to side and rotational). If the hip loses its ability to be mobile, you get low back pain. Most lower back pain is not caused by a weak back, it is most often caused by a tight and immobile hip. To work on increasing hip mobility, we will go through a series of hip drills (leg swings front to back and side to side; wide squats). With some clients we will also use a form of lunge on a block. This exercise is called a dynamic warm up in that we are using body weight and a little momentum to increase the range of movement in the lunge. We also use everyone's favorite exercise – the Bulgarian squat – to increase the hip's range of motion.
The lumbar spine or “low back” needs to be stable. Great strides have been made in recent years in understanding the function of low back. Shirley Sahrmann (2) and Porterfield and De Rosa (3)say that increasing range of motion through the lumbar spine isn't recommended and can be dangerous. For our clients we do not do rotational exercises where the pelvis is staying locked and you are twisting side to side. Our warm up at the very beginning of our program is rotating, but we also need to ensure your whole hip and foot are rotating to the direction you are moving the ball. So, the rotation is happening through the hip, not the lower back. Also for you golfers, the cable chop exercise is also done rotating the hip and foot to the direction you are moving. In other words you are “leading with the hips” not the lower back or the shoulders.
This should help explain the difference between mobility and flexibility and the need to have both. But, ways to improve each of them are different.
Till next time,
Narina Prokosch, RN CPT
“Monitoring, Mentoring, Motivation”
Mobility vs. Flexibility, Part 2