much love for shoulder flexion
Posted: Wed Mar 24, 2010 1:51 am
I'm writing this post out of recent ponderings about the vault. We always say that vaulters need to be strong, fast, kinesthetically aware, etc. But when? Do we need to be kinesthetically aware on the runway? Do we need to be fast when we're inverted? These could be argued. Nevertheless, the athletic characteristic "strength" does come into play pretty heavily in certain parts of the vault, the swing for example. However I believe the role of strength in the plant is very misunderstood.
We vaulters tend to make assumptions about the sport and sometimes never delve deeper to figure out the intricate workings. This is exemplified by the majority of us limiting ourselves by not using the 6.40 model for the last 50 years. Another feature of the vault which I believe is greatly overlooked is the role of shoulder flexion (NOT PUSHING UP ON THE POLE, that is a combination of shoulder adduction and extension) following takeoff. At plant a great amount of energy is directed back toward the vaulter through the pole into the hands. We used to refer to this as getting into "the pocket" but this term has become synonymous with a passive takeoff, so could call it the hang drive if you want, it doesn't really matter. What matters is that you understand that this force must be resisted by the shoulder flexors (and to an extent the elbow flexors) or else you'll get clothes-lined something fierce and probably end up on your back in the box (if you want to try this just run down the runway and plant and go completely limp except for your hand muscles). Up to this point I believe most people tend to agree with what I just wrote.
HOWEVER, any powerful movement using the amorisation phase and conversion of kinetic energy into elastic energy is subject to muscle dampening and therefore energy loss. If a vaulter is not strong enough in his/her shoulder flexors to resist the pole, there will be an overstretch of the anterior muscles, energy will bleed out of the system, and a powerful elastic rebound will become impossible(Think about trying to do a depth jump off of an 8 foot platform compared to a 18" box, which jump do you think will be higher?). This is common in younger vaulters and I believe is a reason why certain coaches are flabbergasted about why their vaulters can't swing well even when they run fast, plant tall and takeoff on. The truth is the vaulter is probably too weak. If you can't resist a force strongly, then it will take longer to slow it down and consequently it will take longer to accelerate in the positive direction (in this case shoulder flexion). In the pole vault we don't have the luxury of time.
This is where I'm gonna get a bit radical. I believe that the role of isometric exercise for the shoulder flexors could be of great help here. Since isometric exercise is not subject to the proprioceptive inhibition that dynamic work is, much greater force can be developed. This can be helpful in the development of starting strength and eccentric strength as well. Some limitations are that it has regional specificity, meaning it only strengthens a small ROM, and can also hinder concentric speed of movement. However due to the very small range of motion the shoulders go though prior to the initiation of the swing, and the relative "slowness" of it (compared to the speed in terms of degrees/second that throwing a baseball takes) I believe these limitations are inconsequential. Therefore, isometric strength training in the relevant joint angles for the plant could assist in slowing down the speed of eccentric movement which in turn shortens the range of motion which increases the amount of kinetic energy converted to elastic energy and speeds up the concentric portion. This will greatly speed up the beginning of the swing and everything that follows.
A few more benefits of training the shoulder flexors isometrically rather than dynamically are:
1. Isometrics tend to result in less mass gains.
2. Isometrics do not take as much time (one set of 6 second reps with about 5-10 seconds of rest in between reps is generally accepted as sufficient)
3. Isometrics expend less energy than dynamics.
4. Isometrics result in less muscle soreness.
We vaulters tend to make assumptions about the sport and sometimes never delve deeper to figure out the intricate workings. This is exemplified by the majority of us limiting ourselves by not using the 6.40 model for the last 50 years. Another feature of the vault which I believe is greatly overlooked is the role of shoulder flexion (NOT PUSHING UP ON THE POLE, that is a combination of shoulder adduction and extension) following takeoff. At plant a great amount of energy is directed back toward the vaulter through the pole into the hands. We used to refer to this as getting into "the pocket" but this term has become synonymous with a passive takeoff, so could call it the hang drive if you want, it doesn't really matter. What matters is that you understand that this force must be resisted by the shoulder flexors (and to an extent the elbow flexors) or else you'll get clothes-lined something fierce and probably end up on your back in the box (if you want to try this just run down the runway and plant and go completely limp except for your hand muscles). Up to this point I believe most people tend to agree with what I just wrote.
HOWEVER, any powerful movement using the amorisation phase and conversion of kinetic energy into elastic energy is subject to muscle dampening and therefore energy loss. If a vaulter is not strong enough in his/her shoulder flexors to resist the pole, there will be an overstretch of the anterior muscles, energy will bleed out of the system, and a powerful elastic rebound will become impossible(Think about trying to do a depth jump off of an 8 foot platform compared to a 18" box, which jump do you think will be higher?). This is common in younger vaulters and I believe is a reason why certain coaches are flabbergasted about why their vaulters can't swing well even when they run fast, plant tall and takeoff on. The truth is the vaulter is probably too weak. If you can't resist a force strongly, then it will take longer to slow it down and consequently it will take longer to accelerate in the positive direction (in this case shoulder flexion). In the pole vault we don't have the luxury of time.
This is where I'm gonna get a bit radical. I believe that the role of isometric exercise for the shoulder flexors could be of great help here. Since isometric exercise is not subject to the proprioceptive inhibition that dynamic work is, much greater force can be developed. This can be helpful in the development of starting strength and eccentric strength as well. Some limitations are that it has regional specificity, meaning it only strengthens a small ROM, and can also hinder concentric speed of movement. However due to the very small range of motion the shoulders go though prior to the initiation of the swing, and the relative "slowness" of it (compared to the speed in terms of degrees/second that throwing a baseball takes) I believe these limitations are inconsequential. Therefore, isometric strength training in the relevant joint angles for the plant could assist in slowing down the speed of eccentric movement which in turn shortens the range of motion which increases the amount of kinetic energy converted to elastic energy and speeds up the concentric portion. This will greatly speed up the beginning of the swing and everything that follows.
A few more benefits of training the shoulder flexors isometrically rather than dynamically are:
1. Isometrics tend to result in less mass gains.
2. Isometrics do not take as much time (one set of 6 second reps with about 5-10 seconds of rest in between reps is generally accepted as sufficient)
3. Isometrics expend less energy than dynamics.
4. Isometrics result in less muscle soreness.