Excerpted from a presentation to teenagers 12 thru 18: Injury Prevention begins with good Posture
Physical therapists are movement specialists, we observe how someone sits, stands walks or runs. We identify and treat injuries or all sorts with the goal of returning the person to their activity as soon as it is safe to do so with out increasing the risk of injury or if they have done a huge fund raiser and just have to run. Usually a PT is seeing someone after they have been injured so we don’t know what there normal was. When someone comes in to see me I start with standing assessment.
Posture particulalry to teenagers is often a dirty word. You get criticized you when you slump in your chair, when you walk around slouched, maybe your shoulders are forward or back is hunched. But the way you sit can directly impact your sports performance. When we sit for a prolonged period of time some muscles are put on slack others are lengthened. When sitting, the psoas is on slack while the glutes and low back muscles are lenghtened. When we stand these muscles are no longer at the optimal length or tension in order to contract. Practicing good postural habits such as sitting up straight, knees in good alignment not dropping out to the side, can offset some of the effects of sitting. Oftent the external rotators of the hips will get very tight. A test for this - lie down on your back and watch how your feet are aligned if they drop out to the side then most likely your hips are too tight which can influence low back issues.
The psoas muscle is often the cause of increased curvature of the lower back. This is an important muscle in running and posture. It is a long muscle which extends from above the navel down thru your belly, pelvis, groin and attaches to the inner thigh. Its main job is to flex the hip. But it also can put a tremendous amount of pressure on the lumbar spine. After a hard workout your back might be achy, can’t stand up straight. You might even feel your belly is distended or your back is arched more then ususal. This is one example.
Good posture allows us to move in the most efficient way possible in general and in sports. The longer the distance the more important being able to maintain good form becomes not only from a performance perspective but also to avoid getting injured. Ok one more posture thing Texting Neck it is now a diagnosis, this is a bad thing.
Cadence, Stride Length and Center of Gravity
These three things: cadence, stride length and center of gravity all have to come together to create optimal running form. In terms of injury prevention what we want to find the form that's optimal for each individual that optimizes these three components. The literature and running research is showing that 85 to 90 RPM or is optimal. In order to accomplish this the runner has to decrease their stride length and increase their cadence. The optimal stride length is one where our foot lands directly underneath our center of gravity. In order for this to happen we have to have good running posture or form. Here is where core strength is very important in order to maintain this upright posture. The runner on the right of this diagram is running from his core rather then from his extremities. The runner on the left will have to use moreforce pushing off with his feet and lower leg muscles. Now, what makes more sense to run using the smallest muscles, the foot and lower leg muscles to lift our body weight or to lean forward and move forward as if you are falling forward and catching yourself. Forceful running were we push off hard is often the cause of lower leg injuries.
Now an interesting thing is footstrike forefoot vs mid foot vs heel strike doesn’t seem to make too much difference as long as the cadence is high 85 to 90 rpm. The main thing is getting the foot under the center of gravity as in the right hand picture.
Running with a metronome is probably the best way to learn to run at 85 to 90 rpm. This cadence will dictate our stride length. Now some of you probably see people that have a really long stride but if you really observe what they're doing is their gait opens up behind them. They're foot contacts the ground immediately under their center of gravity and their leg trails out behind them. When we run from our core you learn to feel that this is where your power is coming from. During one running cycle, when the right foot strikes the ground the left heel will be lifted up towards the butt from the hamstrings and hip flexors (the psoas again), knee extension occurs as the foot comes through just prior to contact. Arm swing is crucial and must be directed in a straight motion not across our body. Optimally the arm swing is elbow does not come past midline nor does the hand as it goes back. At the same time there is a rotational force between the upper body and lower body. The right shoulder should be at the furthest position backward when the left foot is being pulled upward. The driving force comes from the runners trunk.
When you practice good postural habits these will help transfer into your sports. Finding the optimal running form for your body is one of the keys to being able to run injury free. Now the last thing, you know your body better then anyone else if training is getting harder or recovery from a workout is taking longer then before you are probably over reaching in your training, over reaching is the beginning of over training, you need to talk with your coach and parents. This is usually the beginning of some over use type injury, form starts to deteriorate and you develop compensations in your gait.