In this post I want to flesh out some of the details of body tension that I have not described yet, I also want to take a stab at defining the sub categories of body tension and I hope to do this through analyzing specific moments in the video of Dave Graham on the Island (V15) that I mentioned in an earlier post. This posts contains descriptions of two sub-types of body tension. In my next post I will address what we might call “classic” body tension.
Here is the link to the Graham video The Island
And here is the link to my Basic Movement Terms Video
I apologize in advance for how technical this post is, but when doing movement analysis it is often necessary to get technical. Keep in mind that this analysis is grounded by two ideas.
The first idea is that in situations when the hold surface is perpendicular to the line of gravity, the contact force is primarily responsible for keeping the hand or foot in place on the hold. On holds that are not perpendicular to the line of gravity the friction force plays a greater role in keeping the hand or foot in place.(1) In these situations, the kinetic chain works to increase the contact force on the hold, thus affecting a proportional increase in the friction force. It’s this use of the kinetic chain that I theorize is a principle aspect of body tension.
The second idea is that the direction of the forces we apply to holds is also a principle aspect of body tension. While there are many different directions of force that we see in climbing moves, for now we will just consider forces between holds that are in similar or in opposing directions; and how these forces relate to the body. I suggest that body positions in which hands or feet are applying force in opposite directions defines one type of body tension such as in compression moves. But body tension in the “classic” sense is constituted, in part, by the fact that the hands and feet are applying forces in similar directions.
First Example: Body Tension Defined by Oppositional Forces
The two shots above show two angles on the same move (although not at the exact same moment.)
There are three points of contact while the left hand is in motion, I am going to focus on the left leg and right arm as these are the body segments applying opposing forces. Looking at the right hand we see that it is a terrible sloper, nowhere near perpendicular to the line of gravity so Graham is relying more on the friction force than the contact force to stay on this hold.(2) As I suggested in previous posts in this situation the climber uses the closed kinetic chain to increase the contact force on the hold, thus increasing the friction force on the hold. In this move we see evidence of this effort coming from the kinetic chain at three places. In the right arm we see flexion of the right elbow and horizontal adduction of the right shoulder.(3) Normally, in this body position in a closed kinetic chain these joint actions would move the body to the right, but here they don’t. The reason they don’t is the oppositional force being created by the left foot, which by dorsal flexion of the ankle is toe hooking the left edge of the roof. This toe hook stabilizes the body, resisting the lateral movement created by the right elbow and shoulder, which means that the actions of the right arm, don’t move the body, but they do increase the contact force on the right hand sloper and the left toe hook. In this kind of situation the climber is applying a great deal of force, but this force creates little if any movement and so the physical sensation in this type of position is one of tension.
Importantly, in the most obvious example of oppositional forces such as opposing side pulls the forces at work run across the body. In the example here, because the kinetic chain involves the left leg, the pelvis, trunk, right shoulder and arm, the oppositional forces run more or less diagonally through the body. It’s my thinking that when tension runs diagonally across the body, or lengthwise through the body that we are most likely to perceive the move as requiring body tension. So it might be possible to say that this move is representative of one sub type of body tension in which oppositional forces work diagonally across the body.
Second Example: Body tension to resist rotational movement
As Graham gets the left hand crimper, he releases the left toe hook. The result of releasing the left toe hook is the involuntary dropping of the left leg, which includes extension of the left hip joint, and severe outward rotation of the right hip joint. The result is that the COG accelerates downward almost yanking Graham off the rock. Recall from my video of basic kinesiology terms that rotation of the hip joint can occur with the foot free or planted. The difference between the two situations is the body segment that moves. With the foot free in an open kinetic chain it’s the leg that rotates in relation to the pelvis. With the foot planted, in a closed kinetic chain, it’s the pelvis that rotates in relation to the leg, which is what we see here. We also see some rotation of the trunk as well: Comparing the first and second stills we see horizontal abduction and extension has occurred in the right shoulder. In the left shoulder we see horizontal adduction but the amount of extension appears to be about the same.
So in this move Graham faces two tasks. The first is to prevent or minimize the outward rotation of the hip in the first place. This is what we prefer because not doing so often means being yanked off the rock by the downward acceleration of the COG. Preventing the outward rotation also allows for faster transition between moves and is more efficient. If the climber can’t prevent the outward rotation, as is the case with Graham here, the climber needs to take corrective action in order to get the foot back on the wall and the COG in an acceptable position to facilitate the next hand move. In this case the corrective action clearly consist of inward rotation of the right hip, and flexion of the left hip. Other than that, this observational angle makes it hard to see what is going on. In an effort to stabalize the shoulders we do see slight horizontal abduction and extension of the left shoulder. In order to maintain contact with his right foot, there must be extension of the trunk, right hip and plantar flexion the left ankle. Without those actions it would be impossible for the right foot to maintain contact. So it’s the entire kinetic chain between the right foot and the left hand that facilitates the corrective movement, and any climber will feel this effort through the length of his or her body.
I have a little more to add about this examples such as the muscles at work in each joint action described above, but that is probably best done in a chart that I will add later. For now the take home points from these examples might be summarized as follows:
1- Oppositional forces in closed kinetic chains are an important part of body tension but the physical sensation of body tension is most likely going to be felt when the forces run the length of the body rather than simply across it.
2- Resisting or correction rotational movement at the hip joint often requires effort of the entire kinetic chain and will create the physical sensation of body tension.
More on the Graham video in the next post.
1. As I’ve mentioned before, its not just the relation of the hold surface to the line of gravity, it’s also the reltion of the hold surface to the COG. In this instance if you draw a line from the right hand’s point of contact, to the approximate position of the COG we see the mechanical value of keeping the body to the left, in that doing so means that the vector from hand to COG is at a somewhat more advantageous angle in relation to the hold than if the COG was directly below the hold, in that case, the vector from hold to COG, the hold surface, and the line of gravity would all be parallel. Which would make it impossible to use this hold.
2. Regarding the right hand there may be some very small ripple in the texture of the sloper. The first still suggests that there is not as the fingers are straight but in the second shot we see flexion of the distal interphalangeal joint of the index finger, and flexion of the proximal interphalangeal joint of the middle finger which may suggest the presence of a ripple. Beyond that possibility no part of the hold is even close to perpendicular to the line of gravity. Also note that the difference in finger positions suggests that the video contains two different takes that have been edited together. Nothing wrong with this, but it may distort our analysis in ways we can’t anticipate because what we are analyzing is not a continuous record of a complete move.
3. There is also extension of the right shoulder but I don’t think this plays much of role in increasing the contact force on the right hand.