[quote]Well, I can't speak about the age factor exactly, since I'm not up there in years like some around here,
I realize you've got years of experience behind you, but would you consider that that maybe you're missing something in your training?
I suspect that my biggest training failure was not to have regular visits with a sports physician and a professional Rolfer.
As far as I know, the tendon/ligament, and fascia shouldn't degrade too rapidly with age. If you have a proper solo training practice then it should be strengthening these facets with age (up to a point).
I've seen this in a fair number of guys with the goods across several different styles. Of course I won't know for myself for at least another 15 years or so...^^;[/
Age leads to death. Oh yeay, that is a tautology as time leads to age and death is an inevitability. Nevertheless, while I am not a sports physician, here is my take on the "unity of motion" thing and sports/chronic aging injuries.
Shoulder issues like chronic biceps tendon injuries can be compensated since arm leverage is the last thing you need to use in a throw. You can bypass the shoulder and even the elbow for that matter and still make "unified motion" technique work. Body throwing (without the arms) is just a reduction of techniques that are taught by throwing through 3 joints (wrist, elbow and shoulder). You can even pin your elbow to your rib cage and complete the throw (isolating the shoulder all together). What Ledyard sensei is calling the "Ikkyo Curve" can also be seen as simply connecting the humerous with the clavicle and scapula so that you can find the center of gravity in the pelvic girdle through the spine and rib cage connections. thus, one torso can throw another torso as long as this connection is made.
Chronic knee injuries can be a bigger issue. The easiest way to drop weight in a "small circle" throwing technique is to bend the knees. What if you cannot? Bending at the waist tends disunify the throw, by taking pressure off the uke's center during the throw . You can still throw with big circles using two out of the three dimensions as long as you use the circle to take the yaw out of the thorax and make it hook up with the pelvis. You still have width and depth even though you lose the element of height during the throw. Many Aikido traditions teach what I would call "wide stances" as the basic curriculum. The throws that naturally occur from wide stances are projection throws and focus on this 2 dimensional force do accomplish the major part of the throw.. Little dropping on height is necessary. But small throwing requires a drop in height of some kind and from some part of the body.
There is a Tomiki instructor in Columbus, Ohio that teaches on crutches due to a medical challenge in his legs. He found another compensation when he cannot use pure projection due to his limitations.. He throws often with the use of aiki set ups and judo "coupling" actions using his crutch like a tripping foot.
The greatest degeneration in "unity of motion" has to do with hip/pelvic girdle problems. This is where your core strength is and where your primary center of gravity resides. If you have a muscle imbalance, for instance, you most likely cannot fully single weight on one foot. And if you get into a wide stance, you cannot minimize/reduce the stance smoothly. Either way, transferring momentum/force through "weight shift" and the connection with uke will likely be disconnected and easily read as primary force..
I suspect that there is a "real world reason" (among others) to be learned when asking why "old man" style has stances where the feet are almost next to each other. Old martial arts teachers had to figure out how to throw and strike without athletic stances, using one leg to support the other without becoming double weighted and losing momentum.
Oh well such a digression. Key lesson, don't let your injuries go untreated. They come back and haunt you when you get older.